Power System Dynamics: Standard Dynamic Model Reference

Common Information Model
for
Power System Dynamics
Standard Dynamic Model
Reference Document
DRAFT
October 28, 2008
Introduction ............................................................................................................................................................................. 4
Standard Interconnections ................................................................................................................................................... 5
Synchronous Generator Unit............................................................................................................................................................................. 5
Asynchronous (Induction) Generator Unit ................................................................................................................................................... 7
Large Synchronous Motor Unit ........................................................................................................................................................................ 8
Large Asynchronous (Induction) Motor Unit............................................................................................................................................... 9
Aggregate Load.....................................................................................................................................................................................................10
Synchronous Generator Models......................................................................................................................................... 11
genSync - Synchronous Generator Model ..............................................................................................................................................13
genSync - RoundRotor Type....................................................................................................................................................................17
genSync - Salient Pole Type......................................................................................................................................................................19
genSync - Transient Type .........................................................................................................................................................................20
genSync - TypeF.............................................................................................................................................................................................20
genSync - TypeJ .............................................................................................................................................................................................21
genSync - CrossCompound Type...........................................................................................................................................................22
genEquiv - Equivalent (Classical ) Generator Model..............................................................................................................................24
Asynchronous Generator Models ...................................................................................................................................... 26
genAsync - Asynchronous Generator Model...........................................................................................................................................28
Large Synchronous Motor Models ..................................................................................................................................... 31
motorSync - Synchronous Motor Model....................................................................................................................................................33
motorSync - RoundRotor Type...............................................................................................................................................................38
motorSync - Salient Pole Type.................................................................................................................................................................40
Large Asynchronous Motor Models................................................................................................................................... 41
motorAsync - Asynchronous Motor Model...............................................................................................................................................42
Voltage Compensation Models .......................................................................................................................................... 45
vcompIEEE - IEEE Voltage Compensation Model....................................................................................................................................47
vcompCross – Cross-Compound Voltage Compensation Model.....................................................................................................48
Excitation System Models.................................................................................................................................................... 49
excAC1A - IEEE AC1A Model ............................................................................................................................................................................51
excAC2A - IEEE AC2A Model ............................................................................................................................................................................53
excAC3A - IEEE AC3A Model ............................................................................................................................................................................55
excAC4A - IEEE AC4A Model ............................................................................................................................................................................57
excAC5A - IEEE AC5A Model ............................................................................................................................................................................59
excAC6A - IEEE AC6A Model ............................................................................................................................................................................61
excAC7B - IEEE AC7B Model ............................................................................................................................................................................63
Page 2
excAC8B - IEEE AC8B Model ............................................................................................................................................................................65
excDC1A - IEEE DC1A Model............................................................................................................................................................................67
excDC2A - IEEE DC2A Model............................................................................................................................................................................69
excDC3A - IEEE DC3A Model............................................................................................................................................................................71
excDC4B - IEEE DC4B Model............................................................................................................................................................................73
excST1A - IEEE ST1A Model..............................................................................................................................................................................75
excST2A - IEEE ST2A Model..............................................................................................................................................................................77
excST3A - IEEE ST3A Model..............................................................................................................................................................................79
excST4B - IEEE ST4B Model..............................................................................................................................................................................81
excST5B - IEEE ST5B Model..............................................................................................................................................................................83
excST6B - IEEE ST6B Model..............................................................................................................................................................................85
excST7B - IEEE ST7B Model..............................................................................................................................................................................87
Other Excitation System Models To Be Added.........................................................................................................................................89
Power System Stabilizer (PSS) Models ............................................................................................................................... 90
pssIEEE2B - IEEE PSS2B Power System Stabilizer Model .................................................................................................................92
Other PSS Models To Be Added......................................................................................................................................................................94
Turbine-Governor Models ................................................................................................................................................... 95
govHydro – Hydro Turbine-Governor Model ............................................................................................................................................97
Other Turbine-Governor Models To Be Added.........................................................................................................................................99
Aggregate Load Models..................................................................................................................................................... 100
loadStatic - Static Load Model...................................................................................................................................................................102
loadMotor - Aggregate Induction Motor Load ...................................................................................................................................104
Mechanical Load Models ................................................................................................................................................... 107
mechload1 - Mechanical Load Model 1 ................................................................................................................................................108
Page 3
Introduction
The CIM standard dynamic models include most models for power system equipment that are
commonly used for analysis of power system dynamic simulations in the transient and oscillatory
stability time scale as defined by IEEE / CIGRE Standard Terms and Definitions for Power System
Stability Analysis [ref].
Each of the models is described in this document, grouped by type of model.
Page 4
Standard Interconnections
This section describes the standard interconnection of models for various types of equipment.
These interconnections are understood by the application programs and therefore do not need to be
communicated with the CIM data. In the interconnection diagrams, a dashed box means that a
model does not have to be present.
Synchronous Generator Unit
A synchronous generator and its related equipment models are associated with a generator in the
static (power flow) data and have the standard interconnections shown in the following figure.
Etr, Eti
Voltage
Compensator
Vcomp
PSS
inputs
Vref
Vs
PSS
Itr, Iti
Network
Algebraic
Equations
Itr2, Iti2
Efd
Excitation
System
Ifd
Synchronous
Generator
generator
terminal
bus
speed
Pref
Pmech
Turbine-Governor
Pmech2
Generator
#2
Notes:
1. The interface between the generator model and the network algebraic equations is
application dependent. The variables used for this interface do not need to be identified
since they are internal to the application program and will not be used by other models.
2. If no Excitation System model is present for a unit, the field voltage (Efd) is held constant
at the initial value.
3. If no Turbine-Governor model is present for a unit, the generator mechanical power
(Pmech) is held constant at the initial value.
4. If no PSS model is present for a unit, the Vs signal is zero. The PSS model may have any
of several variables as inputs. The identification of the type of variable and its source is
part of the data for the PSS model.
Page 5
5. If no Voltage Compensator is present for at unit, Vcomp is set equal to the magnitude of the
terminal voltage.
6. Generator #2 is the second unit of a cross-compound pair of generators and is usually
connected to the same terminal bus. A single Turbine-Governor model determines the
mechanical power for both units. A Voltage Compensator model that uses the currents
from both units may be used. Therefore, the Turbine-Governor and Voltage Compensator
models must have provision for being associated with two generating units.
7. The Vref and Pref variables are shown because they are standard inputs to the Excitation
System and Turbine-Governor, respectively. These variables may be the output of nonstandard models, e.g. for secondary voltage and frequency controls.
Page 6
Asynchronous (Induction) Generator Unit
An asynchronous generator and its related equipment models are associated with a generator in the
static (power flow) data and have the standard interconnections shown in the following figure.
This is for a “squirrel-cage” induction machine or a wound-rotor induction machine with shortcircuited field windings. Other models and interconnections are required for a wound-rotor
machine with external connections to the field windings.
Network
Algebraic
Equations
speed
Pref
Turbine -Governor
Pmech
Asynchronous
Generator
generator
terminal
bus
Notes:
1. The interface between the generator model and the network algebraic equations is
application dependent. The variables used for this interface do not need to be identified
since they are internal to the application program and will not be used by other models.
2. If no Turbine-Governor model is present for a unit, the generator mechanical power
(Pmech) is held constant at the initial value.
Page 7
Large Synchronous Motor Unit
A synchronous motor and its related equipment models are associated with a generator (with
negative Pgen) in the static (power flow) data and have the standard interconnections shown in the
following figure.
Etr, Eti
PSS
inputs
Voltage
Compensator
Vcomp
Vref
PSS
Vs
Itr, Iti
Network
Algebraic
Equations
Efd
Excitation
System
Ifd
Synchronous
Motor
generator
terminal
bus
speed
Mechanical Load
Pmech
Notes:
1. The interface between the motor model and the network algebraic equations is application
dependent. The variables used for this interface do not need to be identified since they are
internal to the application program and will not be used by other models.
2. If no Excitation System model is present for a unit, the field voltage (Efd) is held constant
at the initial value.
3. If no Mechanical Load model is present for a unit, the motor mechanical power (Pmech) is
held constant at the initial value.
4. If no PSS model is present for a unit, the Vs signal is zero. The PSS model may have any
of several variables as input. The identification of the type of variable and its source is part
of the data for the PSS model.
5. If no Voltage Compensator is present for at unit, Vcomp is set equal to the magnitude of the
terminal voltage.
Page 8
Large Asynchronous (Induction) Motor Unit
An asynchronous motor and its related equipment models are associated with a generator (with
negative Pgen) in the static (power flow) data and have the standard interconnections shown in the
following figure. This is for a “squirrel-cage” induction machine or a wound-rotor induction
machine with short-circuited field windings. Other models and interconnections are required for a
wound-rotor machine with external connections to the field windings.
Network
Algebraic
Equations
speed
Mechanical Load
Pmech
Asynchronous
Motor
generator
terminal
bus
Notes:
1. The interface between the motor model and the network algebraic equations is application
dependent. The variables used for this interface do not need to be identified since they are
internal to the application program and will not be used by other models.
2. If no Mechanical Load model is present for a unit, the motor mechanical power (Pmech) is
held constant at the initial value.
Page 9
Aggregate Load
An aggregate load is associated with a load in the static (power flow) data and has the standard
interconnection shown in the following figure.
Vbus, fbus
Network
Algebraic
Equations
Load Model
Pload
Qload
load
terminal
bus
Load Model Standard Interconnections
Notes:
1. The interface between the model and the network algebraic equations is application
dependent. The variables used for this interface do not need to be identified since they are
internal to the application program and will not be used by other model.
a. For static (non-dynamic) load models, the P and Q consumption of the load is
determined as a function of the magnitude and frequency of the voltage at the
terminal bus.
b. For dynamic load models, the interface is similar to that of a generator model.
Page 10
Synchronous Generator Models
For conventional power generating units (e.g., thermal, hydro, combustion turbine), a synchronous
machine model represents the electrical characteristics of the generator and the mechanical
characteristics of the turbine-generator rotational inertia. The standard interconnection variables
between a synchronous generator model and other models are shown in the following figure and
table:
Efd
Excitation
System
E”d, E”q*
Ifd
Synchronous
Generator
speed
Turbine Governor
angle
Network
Equations
Id, Iq*
Pmech
* Network interface variables may differ among application programs
Synchronous Generator Interconnection Variables
The interconnection with the electrical network equations may differ among application programs.
The program only needs to know the terminal bus and generator ID to establish the correct
interconnection.
Synchronous Generator Interconnection Variables
Model Type
Inputs:
Name
Synchronous Generator
Units
Description
Source
Efd
Pmech
p.u.
p.u.
Field voltage on base of Ifag * Rfd (field resistance)
Mechanical shaft power to the generator
Outputs:
Name
Speed
Angle
Units
p.u.
radians
Eppd
Eppq
Ifd
p.u.
p.u.
p.u.
Description
Generator (electrical) speed
Generator rotor angle relative to synchronously-rotating reference
frame
Direct-axis subtransient voltage
Quadrature-axis subtransient voltage
Field current on Ifag base
Page 11
Exciter
Turbine
The following variables may be calculated in the generator model or in the network solution
depending on the particular application program:
Pgen
p.u.
Electrical power
Qgen
p.u.
Reactive power
Eterm
p.u.
Terminal voltage
Iterm
p.u.
Terminal current magnitude
Initialization Inputs:
Name
Units
Eterm
busAngle
Pgen
Qgen
p.u.
radians
MW
MVAr
Description
Terminal voltage magnitude
Terminal voltage angle relative to system reference
Electrical power
Reactive power
Source
Power Flow
Power Flow
Power Flow
Power Flow
Initialization Outputs:
Name
Units
Description
Speed
p.u.
Generator (electrical) speed (= 1.0 initially)
Angle
radians Generator rotor angle relative to synchronously-rotating reference
frame
Efd
p.u.
Field voltage on base of Ifag * Rfd (field resistance)
Ifd
p.u.
Field current on Ifag base (= Efd initially)
Pmech
p.u.
Mechanical shaft power to the generator
Notes:
1. Input/output variable units (except for angle) should be kept in per unit. Attempts to
convert to engineering units would be confusing. Since these variable are not directly
attributes of CIM classes, this should not conflict with CIM standards.
2. The interface between the generator model and the network algebraic equations is
application dependent. The variables used for this interface do not need to be specified
since they are internal to the application program and will not be used by other models, e.g.
user-written models.
3. If no Excitation model is present for a unit, the field voltage (Efd) should be held constant
at the initial value.
4. If no Turbine-Governor model is present for a unit, the generator mechanical power
(Pmech) should be held constant at the initial value.
References
Most of the standard synchronous machine models are based on modeling practices described in
IEEE Standard 1110-1991, “IEEE Guide for Synchronous Generator Modeling Practices in
Stability Analysis.”
Page 12
genSync - Synchronous Generator Model
A single standard synchronous model is defined for the CIM, with several variations indicated by
the “model type” attribute. This model can be used for all types of synchronous machines (salient
pole, solid iron rotor). A simplified model (genEquiv) is also defined below for representation of
groups of generators that are not modeled in detail. All types of the genSync model use a subset of
the same data parameters and input/output variables The input parameters are shown in the
following table:
Model Name
genSync
Description
Synchronous generator model with several variations
Parameters:
Parameter
Name
Bus number
Unit ID
Model Type
MVAbase
kVbase
Ra
Xl
Xd
Xpdv
Usual
Units
CIM
Units??
Typical
Value
None
MVA
kV
p.u.
p.u.
p.u.
p.u.
Xppdv
p.u.
0.2
Xq
Xpq
Xppq
Tpdo
Tppdo
Tpqo
Tppqo
H (note 2)
D (note 3)
S1 (note4)
S12 (note 4)
p.u.
p.u.
p.u.
sec.
sec.
sec.
sec.
sec.
none
none
none
none
none
none
1.6
0.3
0.2
5.0
0.03
0.5
0.03
3.0
0.0
0.02
0.12
Ks
Pfrac
none
none
none
none
0.0
1.0
None
MVA
kV
0.005
0.15
1.8
0.5
sec.
sec.
sec.
sec.
Description
Terminal bus number in power flow case
Generator ID in power flow case
See table below
MVA base for p.u. values
kV base for p.u. values
Stator resistance (>= 0.)
Stator leakage reactance (> 0.)
D-axis synchronous reactance (>= Xpdv)
D-axis transient reactance (unsaturated) (>
=X”dv)
D-axis sub-transient reactance (unsaturated) (>
Xl)
Q-axis synchronous reactance (> =Xpq)
Q-axis transient reactance (> =Xppq)
Q-axis sub-transient reactance (> Xl)
D-axis transient rotor time constant (> Tppdo)
D-axis sub-transient rotor time constant (> 0.)
Q-axis transient rotor time constant (> Tppqo)
Q-axis sub-transient rotor time constant (> 0.)
Inertia constant of turbine-generator (> 0.)
Damping factor
Saturation factor at rated term. voltage (>= 0.)
Saturation factor at 120% of rated term.
voltage (>=S1)
Saturation loading correction factor (>= 0.)
Fraction of power flow generator P (>= 0.)
1. Generator parameters such as Xl, Xd, etc. are actually used as inductances (L) in the
models, but are commonly referred to as reactances since, at nominal frequency, the per
unit values are the same. However, some references (e.g. PSLF User Manual) use the
Page 13
symbol L instead of X. Also, the “p” in the parameter names is a substitution for a “prime”
in the usual notation, e.g. Xppd refers to X”d.
2. H is the stored energy in the rotating mass of the generator plus all other elements
(turbine, exciter) on the same shaft and has units of MW-sec. Conventional units are per
unit on the generator MVA base, usually expressed as MW-sec./MVA or just sec. (since
MW and MVA are equivalent units).
3. D has units of power/speed but is regarded as a dimensionless factor resulting from
linearization of an exponential relationship between speed and power: P = Po (ω)D . This
value is often zero when the source of damping torques (generator damper windings, load
damping effects, etc.) are modeling in detail. [ref]
4. Saturation factors (S1, S12) are defined by S(E1) and S(E2) in Figure genSync1
OPEN
CIRCUIT
VOLTAGE
AIR GAP LINE
OPEN CIRCUIT
MAGNETIZATION
CURVE
E2
OBi - OAi
S(E) = --------------OAi
E1
For generators
E1 = 1.0
E2 = 1.2
For Exciters
E1, E2 are parameters
0
A1 B1 A2
B2
MAGNETIZING
CURRENT
Figure genSync1 -- Synchronous Generator Saturation Parameters
Note: The quantity OA1 in amperes is normally called Ifag -- Field current at rated voltage, open
circuit on the air gap (no saturation) line.
Page 14
Model Equations:
The mechanical equations for all variatons of the genSync model are the same and can be
represented by the following block diagram:
1.
Te
Pmech
d
n
Σ
n/d
Tm +
_
Σ
_
+
ω
Σ
+
∆ω
1
2Hs
speed
ωo
s
angle
D
Figure genSync2 -- Synchronous Generator Mechanical Equation Block Diagram
All variables are per unit on generator MVA base except angle, which is in radians. ωo is the
system synchronous frequency in radians per second, e.g. 377. for 60Hz. systems.
The electrical equations for all variations of the genSync model are based on the following
equivalent circuit diagram for the direct and quadrature axes:
Ra
Xl
Rfd
Xfd
Rkd
efd
Xad
d axis
+
Xkd
Ra
Xl
R1q
X1q
R2q
q axis
Xaq
X2q
Figure genSync3 -- Synchronous Generator Equivalent Circuit
Page 15
In each axis, the branches represent the stator leakage reactance (Xl) and resistance (Ra), the
magnetizing reactance (Xad, Xaq), the physical field winding (Rfd, Xfd, efd) on the rotor, and
equivalent windings for eddy current flow in the rotor iron. This equivalent circuit makes the
assumption of equal mutual inductance among all of the windings (rotor to stator, rotor d to rotor
q). Models based on unequal mutual inductance are not normally used for stability analysis.
The definition of d and q axis variables is based on the following phasor diagram (counterclockwise rotation), for the case of an overexcited generator (generating Q):
q axis
j It ( Xq-X”)
E”
rotor angle
Et
bus angle
It
It (Ra + jX”)
Network
Reference
d axis
Figure genSync4 -- Synchronous Generator Phasor Diagram
The relationships between the equivalent circuit parameters and the standard model parameters are
as follows:
Xd = Xad + Xl
X’d = Xl + Xad * Xfd / (Xad + Xfd)
X”d = Xl + Xad * Xfd* Xkd / (Xad * Xfd + Xad * Xkd + Xfd * Xkd)
T’do = (Xad + Xfd) / (wo * Rfd)
T”do = (Xad * Xfd + Xad * Xkd + Xfd * Xkd) / (wo * Rkd * (Xad + Xfd)
Xq = Xaq + Xl
X’q = Xl + Xaq * X1q / (Xaq+ X1q)
X”q = Xl + Xaq * X1q* X2q / (Xaq * X1q + Xaq * X2q + X1q * X2q)
T’qo = (Xaq + X1q) / (wo * R1q)
T”qo = (Xaq * X1q + Xaq * X2q + X1q * X2q)/ (wo * R2q * (Xaq + X1q)
The several variations of the genSync model described on the following pages differ in the
following ways:
• The number of equivalent windings that are included
• The way in which saturation is incorporated into the model.
Page 16
•
•
Whether or not “subtransient saliency” (Xppq ≠ Xppdv) is represented.
Whether or not multiple units (e.g. cross-compound set) are represented individually in the
static (power flow) data.
Variations of the genSync model are identified by the “model type” attribute as shown in the table
below, together with the corresponding model names in each application program. Each model
type is described in detail on the following pages.
CIM
Model Type
RoundRotor
SalientPole
Transient
TypeF
TypeJ
CrossCompound
PSLF
Model
genrou
gensal
(genrou)
gentpf
gentpj
gencc
PSS/E
Model
GENROU
GENSAL
GENTRA
DigSilent
Model
ElmSym
ElmSym
ElmSym
Eurostag
Model
GENROU?
Note: It is not necessary for each program to have separate models for each of the model types.
The same model can often be used for several types by alternative logic within the model. Also,
differences in saturation representation may not result in significant model performance differences
so model substitutions are often acceptable.
genSync - RoundRotor Type
The complete equivalent circuit is used with two rotor windings in each axis.
Notes:
•
•
•
Xppq is assumed to be equal to Xppd (no subtransient saliency)
Saturation is modeled in both the d and q axes as shown in the block diagram
The following input parameters are not used: Xppq, Ks, Pfrac
Block Diagram:
Page 17
iq
Efd
Σ
1
sT' do
1
sT' ' do
Σ
ψkd
X' d − X' ' d
( X' d − Xl) * *2
Σ
Ifd
ω
X' ' d − Xl
X' d − Xl
ψfd
X' d − X' ' d
X' d − Xl
Σ
X'd-Xl
ψ"d
Ra
Eq
Π
Σ
X''d
d-AXIS
id
Σ
Xd-X'd
ψ" = sqrt(ψ"d2+ψ"d2)
ψ" d
Se
ψ"q
Xq − Xl
Xd − Xl
Xq-X'q
Σ
Σ
X' q − X' ' q
( X' q − Xl) * *2
ψ1q
Σ
1
sT' qo
Σ
1
sT' ' qo
iq
q-AXIS
X'q-Xl
ψ2q
X' q − X' q
X' q − Xl
X' ' q − Xl
X' q − Xl
X''q
ψ"q
Σ
Π
Σ
Ed
ω
Ra
id
Figure genSync5 -- genSync – RoundRotor Type Model Block Diagram
Page 18
genSync - Salient Pole Type
The d-axis equivalent circuit is the same as for the RoundRotor type. The q-axis has only one
equivalent rotor winding, which may be labeled as transient (Xpq) or subtransient (Xppq) – Xpq is
used for the CIM description.
Notes:
•
•
•
Xppq (=Xpq) is assumed to be equal to Xppdv (no subtransient saliency)
Saturation is modeled in the d axis only as shown in the block diagram
The following input parameters are not used: Xpq, Xppq, Tppqo, Ks, Pfrac
Block Diagram:
iq
Efd
Σ
1
sT' do
ω
X' ' d − Xl
X' d − Xl
ψfd
1
sT' ' do
Σ
ψkd
X' d − X' ' d
X' d − Xl
X' d − X' ' d
( X' d − Xl) * *2
Σ
X'd-Xl
ψ"d
Ra
Eq
Π
Σ
X''d
d-AXIS
Se ψfd
Ifd
Σ
Xd-X'd
id
Σ
iq
Xq-X'q
X''q
q-AXIS
Σ
1
sT' qo
ψ1q ψ" q
Π
Σ
Ed
ω
Ra
id
Figure genSync6 -- genSync – SalientPole Type Model Block Diagram
Page 19
genSync - Transient Type
The d-axis equivalent circuit has only the field winding. The q-axis has only one equivalent rotor
winding, which may be labeled as transient (Xpq) or subtransient (Xppq) – Xpq is used for the
CIM description.
Notes:
•
•
•
??? Xppq (=Xpq) is assumed to be equal to Xppdv (=Xpd) (no subtransient saliency)
Saturation is modeled in the d axis only as shown in the block diagram
The following input parameters are not used: Xppd, Xpq, Xppq, Tpdo, Tppqo, Ks, Pfrac
Block Diagram:
Add figure later
Figure genSync7 -- genSync – Transient Type Model Block Diagram
genSync - TypeF
This model has a similar level of detail to the RoundRotor type but permits subtransient saliency
(Xppq ≠ Xppdv) and models saturation differently. The RoundRotor type can usually be
substituted without significant loss of accuracy.
Notes:
•
•
Saturation is modeled in both the d and q axes as shown in the block diagram
The following input parameters are not used: Ks, Pfrac
Block Diagram:
Page 20
Ld − L' d
L' d − L ' ' d
∑
Efd
1
sT' do
Se
E’q
Se
∑
Ld − L" d
L' d − L' ' d
1
sT' ' do
L’d - L”d
ϕ" d
E”q
id
Se = 1. + fsat( ϕag)
Q − Axis similar except :
Se = 1. +
Lq
( ϕag)
Ld
Figure genSync9 -- genSync – TypeF Model Block Diagram
genSync - TypeJ
This model is the same as TypeF but includes the effect of generator loading on saturation.
Notes:
•
•
Saturation is modeled in both the d and q axes as shown in the block diagram
The following input parameters are not used: Pfrac
Block Diagram:
Page 21
Ld − L' d
L' d − L' ' d
∑
Efd
1
sT' do
Se
E’q
Se
∑
Ld − L" d
L' d − L' ' d
1
sT' ' do
L’d - L”d
ϕ" d
E”q
id
Se = 1. + fsat(ϕag + Kis ∗ It ∗ sign(id))
Q − Axis similar except :
Se = 1. +
Lq
∗ fsat (ϕag + Kis ∗ It ∗ sign(id))
Ld
Figure genSync10 -- genSync – TypeJ Model Block Diagram
genSync - CrossCompound Type
This model is the same as RoundRotor Type but permits more than one genSync model to split the
generator power from the power flow synchrounous machine model. This is most often used for
representing the two untis of a cross-compound set which always operate together from the same
steam supply.
Notes:
•
•
•
•
The parameter Pfrac is the fraction of the power flow Pgen and Qgen supplied by this unit.
Xppq is assumed to be equal to Xppd (no subtransient saliency)
Saturation is modeled in both the d and q axes as shown in the block diagram
The following input parameters are not used: Xppq, Ks
Block Diagram:
Page 22
iq
Efd
Σ
1
sT' do
1
sT' ' do
Σ
ψkd
X' d − X' ' d
( X' d − Xl) * *2
Σ
Ifd
ω
X' ' d − Xl
X' d − Xl
ψfd
X' d − X' ' d
X' d − Xl
Σ
X'd-Xl
ψ"d
Ra
Eq
Π
Σ
X''d
d-AXIS
id
Σ
Xd-X'd
ψ" = sqrt(ψ"d2+ψ"d2)
ψ" d
Se
ψ"q
Xq − Xl
Xd − Xl
Xq-X'q
Σ
Σ
X' q − X' ' q
( X' q − Xl) * *2
ψ1q
Σ
1
sT' qo
Σ
1
sT' ' qo
iq
q-AXIS
X'q-Xl
ψ2q
X' q − X' q
X' q − Xl
X' ' q − Xl
X' q − Xl
X''q
ψ"q
Σ
Π
Σ
Ed
ω
Ra
id
Figure genSync11 -- genSync – CrossCompound Type Model Block Diagram
Page 23
genEquiv - Equivalent (Classical ) Generator Model
This model represents a synchronous generator as a constant internal voltage behind an impedance
(Ra +jXpdv) as shown in the following equivalent circuit:
Notes:
•
•
•
•
Since internal voltage is held constant, there is no genEfd input and any excitation system
model will be ignored. There is also no genIfd output.
This model should never be used for representing a real generator except, perhaps, small
generators whose response is insignificant.
The model is often used for gross equivalents of parts of a system that are not represented in
detail. In this case. the MVA rating would be the combined rating of all generators in the
equivalenced area. Ra + jXpdv would be the short circuit equivalent impedance at the
location of the equivalent generator on the generator MVA rating base. H and D would be
typical or average values for the generators in the equivalenced area.
The internal reactance may be labeled in different ways (Xp, Xpp, Xpd, Xppd) by different
programs. The Xpdv value from the genSync input data is selected for use by the CIM
model.
Block Diagram:
The mechanical equations for the genEquiv model are the same as for genSync as shown in Figure
genSync2.
Add figure later
Figure genEquiv1 -- Equivalent (Classical) Model Block Diagram
CIM
Model Name
genEquiv
PSLF
Model
gencls
PSS/E
Model
GENCLS
DigSilent
Model
ElmSym
Eurostag
Model
Parameters:
Parameter
Name
Bus number
Unit ID
Model Type
MVAbase
kVbase
Ra
Xpdv
Page 24
Usual
Units
None
MVA
kV
p.u.
p.u.
CIM
Units??
None
MVA
kV
ohms
ohms
Typical
Value
0.005
0.5
Description
Terminal bus number in power flow case
Generator ID in power flow case
See table below
MVA base for p.u. values
kV base for p.u. values
Stator resistance (>= 0.)
D-axis transient reactance (unsaturated) (> 0.)
H
D
sec.*
none**
MW-sec.
none
3.0
0.0
Inertia constant of turbine-generator (> 0.)
Damping factor
1. Parameter Xpd is actually used as an inductance (L) in the model, but is commonly referred
to as a reactance since, at nominal frequency, the per unit values are the same. However,
some references (e.g. PSLF User Manual) use the symbol L instead of X. Also, the “p” in
the parameter name is a substitution for a “prime” in the usual notation, e.g. Xpd refers to
X’d.
2. H is the stored energy in the rotating mass of the generator plus all other elements
(turbine, exciter) on the same shaft and has units of MW-sec. Conventional units are per
unit on the generator MVA base, usually expressed as MW-sec./MVA or just sec. (since
MW and MVA are equivalent units).
3. D has units of power/speed but is regarded as a dimensionless factor resulting from
linearization of an exponential relationship between speed and power: P = Po (ω)D . This
value is often zero when the source of damping torques (generator damper windings, load
damping effects, etc.) are modeling in detail. [ref]
Page 25
Asynchronous Generator Models
The standard interconnection variables between an asynchronous generator model and other
models are shown in the following figure and table:
E”d, E”q*
speed
Turbine Governor
Network
Equations
Asynchronous
Generator
Id, Iq*
Pmech
* Network interface variables may differ among application programs
Asynchronous Generator Interconnection Variables
The interconnection with the electrical network equations may differ among application programs.
The program only needs to know the terminal bus and generator ID to establish the correct
interconnection.
Asynchronous Generator Interconnection Variables
Model Type
Inputs:
Name
Asynchronous Generator
Units
Pmech
p.u.
Outputs:
Name
Speed
Eppd
Eppq
Units
p.u.
p.u.
p.u.
Description
Mechanical shaft power to the generator
Source
Turbine
Description
Generator (electrical) speed
Direct-axis subtransient voltage
Quadrature-axis subtransient voltage
The following variables may be calculated in the generator model or in the network solution
depending on the particular application program:
Pgen
p.u.
Electrical power
Qgen
p.u.
Reactive power
Eterm
p.u.
Terminal voltage
Iterm
p.u.
Terminal current magnitude
Page 26
Initialization Inputs:
Name
Units
Eterm
busAngle
Pgen
Qgen
p.u.
radians
MW
MVAr
Description
Terminal voltage magnitude
Terminal voltage angle relative to system reference
Electrical power
Reactive power
Source
Power Flow
Power Flow
Power Flow
Power Flow
Initialization Outputs:
Name
Units
Description
Speed
p.u.
Generator (electrical) speed (= 1.0 initially)
Pmech
p.u.
Mechanical shaft power to the generator
Notes:
1. Input/output variable units should be kept in per unit. Attempts to convert to engineering
units would be confusing. Since these variable are not directly attributes of CIM classes,
this should not conflict with CIM standards.
2. The interface between the generator model and the network algebraic equations is
application dependent. The variables used for this interface do not need to be specified
since they are internal to the application program and will not be used by other models, e.g.
user-written models.
3. If no Turbine-Governor model is present for a unit, the generator mechanical power
(Pmech) should be held constant at the initial value.
Page 27
genAsync - Asynchronous Generator Model
The genAsynch model represents an asynchrounous (induction) generator with no external
connection to the rotor windings, e.g squirel-cage induction machine.
Model Name
genAsync
Description
Asynchronous generator model
Parameters:
Parameter
Name
Bus number
Unit ID
MVAbase
kVbase
Rs
Xls
Xs
Xp
Xpp
Tpo
Tppo
H (note 2)
Usual
Units
MVA
kV
p.u.
p.u.
p.u.
p.u.
p.u.
sec.
sec.
sec.
D (note 3)
S1 (note4)
S12 (note 4)
none
none
none
CIM
Units??
Typical
Value
MVA
kV
sec.
sec.
none
none
none
0.005
0.15
1.8
0.5
0.2
5.0
0.03
3.0
0.0
0.02
0.12
Description
Terminal bus number in power flow case
Motor (generator) ID in power flow case
MVA base for p.u. values
kV base for p.u. values
Stator resistance (>= 0.)
Stator leakage reactance (> 0.)
Synchronous reactance (>= Xp)
Transient reactance (unsaturated) (> =Xpp)
Sub-transient reactance (unsaturated) (> Xl)
Transient rotor time constant (> Tppo)
Sub-transient rotor time constant (> 0.)
Inertia constant of motor and mechanical load
(> 0.)
Damping factor
Saturation factor at rated term. voltage (>= 0.)
Saturation factor at 120% of rated term.
voltage (>=S1)
1. Generator parameters such as Xls, Xs, etc. are actually used as inductances (L) in the
model, but are commonly referred to as reactances since, at nominal frequency, the per unit
values are the same. However, some references (e.g. PSLF User Manual) use the symbol L
instead of X. Also, the “p” in the parameter names is a substitution for a “prime” in the
usual notation, e.g. Xpp refers to X”.
2. H is the stored energy in the rotating mass of the generator plus all other elements
(turbine, exciter) on the same shaft and has units of MW-sec. Conventional units are per
unit on the generator MVA base, usually expressed as MW-sec./MVA or just sec. (since
MW and MVA are equivalent units).
3. D has units of power/speed but is regarded as a dimensionless factor resulting from
linearization of an exponential relationship between speed and power: P = Po (ω)D . This
value is often zero when the source of damping torques (damper windings, load damping
effects, etc.) are modeling in detail. [ref]
4. Saturation factors (S1, S12) are defined by S(E1) and S(E2) in Figure genSync1 above.
Page 28
Model Equations:
The mechanical equations for the motorAsync model can be represented by the following block
diagram:
d
Pmech
+
n
Σ
n/d
1.
Te
_
Tm +
1
2Hs
Σ
+
Σ
+
∆ω
ω
speed
slip
_
D
Figure genAsync1 Asynchronous Generator Mechanical Equation Block Diagram
All variables are per unit on motor MVA base except angle, which is in radians. ωo is the system
synchronous frequency in radians per second, e.g. 377. for 60Hz. systems.
The electrical equations of the genAsync model are based on the following equivalent circuit
diagram for the direct and quadrature axes, with two equivalent rotor windings in each axis:
Rs
d axis
Xls
Rr1
Rr2
Xlr1
Xlr2
Xm
q axis – same as d -axis
Figure genAsync2 Asynchronous Generator Equivalent Circuit
In each axis, the branches represent the stator leakage reactance (Xls) and resistance (Rs), the
magnetizing reactance (Xm), and the resistance and leakage reactance of equivalent windings (Rr1,
Xlr1, etc.) on the rotor.
The relationships between the equivalent circuit parameters and the standard model parameters are
as follows:
Page 29
Xd = Xm + Xls
Xp = Xls + Xm * Xlr1 / (Xm + Xlr1)
Xpp = Xls + Xm * Xlr1* Xlr2 / (Xm * Xlr1 + Xm * Xlr2 + Xlr1 * Xlr2)
Tpo = (Xm + Xlr1) / (wo * Rr1)
Tppo = (Xm * Xlr1 + Xm * Xlr2 + Xlr1 * Xlr2) / (wo * Rr2 * (Xm + Xlr1)
If Xpp = Xp, a single cage (one equivalent rotor winding per axis) is modeled.
CIM
Model Type
genAsync
PSLF
Model
genind or
motor1
PSS/E
Model
CIMTR1
CIMTR3
DigSilent
Model
ElmAsm
Eurostag
Model
A specific block diagram for an asynchronous generator model is not shown. There will be
variations in modeling among the application programs which should not materially affect the
results in the stability analysis time scale. (ref Krause book/papers)
Page 30
Large Synchronous Motor Models
Large industrial motors or groups of similar motors may be represented by individual motor models
(synchronous or asynchronous) which are represented as generators with negative Pgen in the
static (power flow) data.
Model Interconnections
Standard interconnection of synchronous motor models with other models are shown in Figure 7-1
and listed in Table 7-1.
Eterm
Efd
Excitation
System
E”d, E”q*
Ifd
Synchronous
Motor
speed
Mechanical
Load
angle
Network
Equations
Id, Iq*
Pmech
* Network interface variables may differ among application programs
Synchronous Motor Interconnection Variables
The interconnection with the electrical network equations may differ among application programs.
The program only needs to know the terminal bus and generator ID to establish the correct
interconnection.
Synchronous Motor Interconnection Variables
Model Type
Inputs:
Name
Efd (note 1)
Pmech
Page 31
Motor
Units
p.u.
p.u.
Description
Field voltage on base of Ifag * Rfd (field resistance)
Mechanical shaft power drawn by mechanical load
Source
Exciter
Mech. Load
Outputs:
Name
Speed
Angle
Eppd
Eppq
Ifd (note 1)
Units
p.u.
radians
p.u.
p.u.
p.u.
Description
Motor (electrical) speed
Motor rotor angle relative to synchronously-rotating reference frame
Direct-axis subtransient voltage
Quadrature-axis subtransient voltage
Field current on Ifag base
The following variables may be calculated in the motor model or in the network solution
depending on the particular application program:
Pgen
p.u.
Electrical power
Qgen
p.u.
Reactive power
Eterm
p.u.
Terminal voltage
Iterm
p.u.
Terminal current magnitude
Initialization Inputs:
Name
Units
Eterm
busAngle
Pgen
Qgen
p.u.
radians
MW
MVAr
Initialization Outputs:
Name
Units
Speed
p.u.
Angle
radians
Efd (note 1) p.u.
Ifd (note 1) p.u.
Pmech
p.u.
Description
Terminal voltage magnitude
Terminal voltage angle relative to system reference
Electrical power
Reactive power
Source
Power Flow
Power Flow
Power Flow
Power Flow
Description
Motor (electrical) speed
Motor rotor angle relative to synchronously-rotating reference frame
Field voltage on base of Ifag * Rfd (field resistance)
Field current on Ifag base (= Efd initially)
Mechanical shaft power drawn by mechanical load
Notes:
1. The interface between the motor model and the network algebraic equations is application
dependent. The variables used for this interface do not need to be specified since they are
internal to the application program and will not be used by other models, e.g. user-written
models.
2. If no exciter model is present for a unit, the field voltage (Efd) should be held constant at
the initial value.
3. If no mechanical load model is present for a unit, the motor mechanical power (Pmech)
should be held constant at the initial value.
Page 32
motorSync - Synchronous Motor Model
A single standard synchronous motor model is defined for the CIM, with several variations
indicated by the “model type” attribute. This model can be used for all types of synchronous
machines (salient pole, solid iron rotor). All types of the motorSync model use a subset of the
same data parameters and input/output variables The input parameters are shown in the following
table:
Model Name
motorSync
Description
Synchronous motor model with several variations
Parameters:
Parameter
Name
Bus number
Unit ID
Model Type
MVAbase
kVbase
Ra
Xl
Xd
Xpdv
Usual
Units
CIM
Units??
Typical
Value
None
MVA
kV
p.u.
p.u.
p.u.
p.u.
Xppdv
p.u.
0.2
Xq
Xpq
Xppq
Tpdo
Tppdo
Tpqo
Tppqo
H (note 2)
p.u.
p.u.
p.u.
sec.
sec.
sec.
sec.
sec.
1.6
0.3
0.2
5.0
0.03
0.5
0.03
3.0
D (note 3)
S1 (note4)
S12 (note 4)
none
none
none
None
MVA
kV
0.005
0.15
1.8
0.5
sec.
sec.
sec.
sec.
none
none
none
0.0
0.02
0.12
Description
Terminal bus number in power flow case
Motor (generator) ID in power flow case
See table below
MVA base for p.u. values
kV base for p.u. values
Stator resistance (>= 0.)
Stator leakage reactance (> 0.)
D-axis synchronous reactance (>= Xpdv)
D-axis transient reactance (unsaturated) (>
=X”dv)
D-axis sub-transient reactance (unsaturated) (>
Xl)
Q-axis synchronous reactance (> =Xpq)
Q-axis transient reactance (> =Xppq)
Q-axis sub-transient reactance (> Xl)
D-axis transient rotor time constant (> Tppdo)
D-axis sub-transient rotor time constant (> 0.)
Q-axis transient rotor time constant (> Tppqo)
Q-axis sub-transient rotor time constant (> 0.)
Inertia constant of motor and mechanical load
(> 0.)
Damping factor
Saturation factor at rated term. voltage (>= 0.)
Saturation factor at 120% of rated term.
voltage (>=S1)
1. Motor parameters such as Xl, Xd, etc. are actually used as inductances (L) in the models,
but are commonly referred to as reactances since, at nominal frequency, the per unit values
are the same. However, some references (e.g. PSLF User Manual) use the symbol L instead
of X. Also, the “p” in the parameter names is a substitution for a “prime” in the usual
notation, e.g. Xppd refers to X”d.
Page 33
2. H is the stored energy in the rotating mass of the motor plus its mechanical load and has
units of MW-sec. Conventional units are per unit on the motor MVA base, usually
expressed as MW-sec./MVA or just sec. (since MW and MVA are equivalent units).
3. D has units of power/speed but is regarded as a dimensionless factor resulting from
linearization of an exponential relationship between speed and power: P = Po (ω)D . This
value is often zero when the source of damping torques (damper windings, load damping
effects, etc.) are modeling in detail. [ref]
4. Saturation factors (S1, S12) are defined by S(E1) and S(E2) in Figure 7-2
OPEN
CIRCUIT
VOLTAGE
AIR GAP LINE
OPEN CIRCUIT
MAGNETIZATION
CURVE
E2
OBi - OAi
S(E) = --------------OAi
E1
For generators
E1 = 1.0
E2 = 1.2
For Exciters
E1, E2 are parameters
0
A1 B1 A2
B2
MAGNETIZING
CURRENT
Figure 7-2 Synchronous Motor Saturation Parameters
Note: The quantity OA1 in amperes is normally called Ifag -- Field current at rated voltage, open
circuit on the air gap (no saturation) line.
Page 34
Model Equations:
The mechanical equations for all variatons of the motorSync model are the same and can be
represented by the following block diagram:
1.
Te
Pmech
d
n
Σ
n/d
+
Tm _
Σ
1
2Hs
+
+
∆ω
Σ
ω
speed
ωo
s
angle
+
D
Figure 7-2 Synchronous Motor Mechanical Equation Block Diagram
All variables are per unit on motor MVA base except angle, which is in radians. ωo is the system
synchronous frequency in radians per second, e.g. 377. for 60Hz. systems.
The electrical equations for all variations of the motorSync model are based on the following
equivalent circuit diagram for the direct and quadrature axes:
Page 35
Ra
Xl
Rfd
Xfd
Rkd
efd
Xad
d axis
+
Xkd
Ra
Xl
R1q
X1q
R2q
q axis
Xaq
X2q
Figure 7-3 Synchronous Motor Equivalent Circuit
In each axis, the branches represent the stator leakage reactance (Xl) and resistance (Ra), the
magnetizing reactance (Xad, Xaq), the physical field winding (Rfd, Xfd, efd) on the rotor, and
equivalent windings for eddy current flow in the rotor iron. This equivalent circuit makes the
assumption of equal mutual inductance among all of the windings (rotor to stator, rotor d to rotor
q). Models based on unequal mutual inductance are not normally used for stability analysis.
The definition of d and q axis variables is based on the following phasor diagram (counterclockwise rotation), for the case of a motor consuming P and overexcited (generating Q):
Page 36
bus angle
Et
It (Ra + jX”)
Network
Reference
E”
It
rotor angle
j It ( Xq-X”)
q axis
d axis
Figure 7-4 Synchronous Motor Phasor Diagram
The relationships between the equivalent circuit parameters and the standard model parameters are
as follows:
Xd = Xad + Xl
X’d = Xl + Xad * Xfd / (Xad + Xfd)
X”d = Xl + Xad * Xfd* Xkd / (Xad * Xfd + Xad * Xkd + Xfd * Xkd)
T’do = (Xad + Xfd) / (wo * Rfd)
T”do = (Xad * Xfd + Xad * Xkd + Xfd * Xkd) / (wo * Rkd * (Xad + Xfd)
Xq = Xaq + Xl
X’q = Xl + Xaq * X1q / (Xaq+ X1q)
X”q = Xl + Xaq * X1q* X2q / (Xaq * X1q + Xaq * X2q + X1q * X2q)
T’qo = (Xaq + X1q) / (wo * R1q)
T”qo = (Xaq * X1q + Xaq * X2q + X1q * X2q)/ (wo * R2q * (Xaq + X1q)
The several variations of the motorSync model described on the following pages differ in the
following ways:
• The number of equivalent windings that are included
• The way in which saturation is incorporated into the model.
• Whether or not “subtransient saliency” (Xppq ≠ Xppdv) is represented.
Variations of the motorSync model are identified by the “model type” attribute as shown in the
table below, together with the corresponding model names in each application program. Each
model type is described in detail on the following pages.
CIM
Page 37
PSLF
PSS/E
DigSilent
Eurostag
Model Type
RoundRotor
SalientPole
Model
genrou
gensal
Model
GENROU
GENSAL
Model
ElmSym
ElmSym
Model
Note: It is not necessary for each program to have separate models for each of the model types.
The same model can often be used for several types by alternative logic within the model. Also,
differences in saturation representation may not result in significant model performance differences
so model substitutions are often acceptable.
motorSync - RoundRotor Type
The complete equivalent circuit is used with two rotor windings in each axis.
Notes:
•
•
•
Xppq is assumed to be equal to Xppd (no subtransient saliency)
Saturation is modeled in both the d and q axes as shown in the block diagram
The following input parameters are not used: Xppq
Block Diagram:
Page 38
iq
Efd
Σ
1
sT' do
1
sT' ' do
Σ
ψkd
X' d − X' ' d
( X' d − Xl) * *2
Σ
Ifd
ω
X' ' d − Xl
X' d − Xl
ψfd
X' d − X' ' d
X' d − Xl
Σ
X'd-Xl
ψ"d
Ra
Eq
Π
Σ
X''d
d-AXIS
id
Σ
Xd-X'd
ψ" = sqrt(ψ"d2+ψ"d2)
ψ" d
Se
ψ"q
Xq − Xl
Xd − Xl
Xq-X'q
Σ
Σ
X' q − X' ' q
( X' q − Xl) * *2
ψ1q
Σ
1
sT' qo
Σ
1
sT' ' qo
iq
q-AXIS
X'q-Xl
ψ2q
X' q − X' q
X' q − Xl
X' ' q − Xl
X' q − Xl
X''q
ψ"q
Σ
Π
Σ
Ed
ω
Ra
id
Figure 7-5 motorSync – RoundRotor Type Model Block Diagram
Page 39
motorSync - Salient Pole Type
The d-axis equivalent circuit is the same as for the RoundRotor type. The q-axis has only one
equivalent rotor winding, which may be labeled as transient (Xpq) or subtransient (Xppq) – Xpq is
used for the CIM description.
Notes:
•
•
•
Xppq (=Xpq) is assumed to be equal to Xppdv (no subtransient saliency)
Saturation is modeled in the d axis only as shown in the block diagram
The following input parameters are not used: Xpq, Xppq, Tppqo
Block Diagram:
L"d - Ll
L'd - Ll
Efd
1
sT' do
Pfd
1
sT' ' do
Pkd
P"d
L'd - L"d
L'd - Ll
d-AXIS
L'd - L"d
L'd - Ll
(L'd - Ll) **2
SePfd
Ld - L'd
id
Lad ifd
1
sT' ' qo
P"q
Pkq
q-AXIS
Lq - Lq”
iq
Figure 7-6 motorSync – SalientPole Type Model Block Diagram
Page 40
Large Asynchronous Motor Models
The standard interconnection variables between an asynchronous motor model and other models
are shown in the following figure and table:
E”d, E”q*
speed
Mechanical
Load
Network
Equations
Asynchronous
Motor
Id, Iq*
Pmech
* Network interface variables may differ among application programs
Asynchronous Motor Interconnection Variables
The interconnection with the electrical network equations may differ among application programs.
The program only needs to know the terminal bus and generator ID to establish the correct
interconnection.
Asynchronous Motor Interconnection Variables
Model Type
Inputs:
Name
Asynchronous Motor
Units
Pmech
p.u.
Outputs:
Name
Speed
Eppd
Eppq
Units
p.u.
p.u.
p.u.
Description
Mechanical shaft power of motor load
Source
Mech. Load
Description
Motor (electrical) speed
Direct-axis subtransient voltage
Quadrature-axis subtransient voltage
The following variables may be calculated in the motor model or in the network solution
depending on the particular application program:
Pe
p.u.
Electrical power
Qe
p.u.
Reactive power
Eterm
p.u.
Terminal voltage
Iterm
p.u.
Terminal current magnitude
Page 41
Initialization Inputs:
Name
Units
Eterm
busAngle
Pgen
Qgen
p.u.
radians
MW
MVAr
Description
Terminal voltage magnitude
Terminal voltage angle relative to system reference
Electrical power
Reactive power
Source
Power Flow
Power Flow
Power Flow
Power Flow
Initialization Outputs:
Name
Units
Description
Speed
p.u.
Motor (electrical) speed (= 1.0 initially)
Pmech
p.u.
Mechanical shaft power to the generator
Notes:
1. Input/output variable units should be kept in per unit. Attempts to convert to engineering
units would be confusing. Since these variable are not directly attributes of CIM classes,
this should not conflict with CIM standards.
2. The interface between the motor model and the network algebraic equations is application
dependent. The variables used for this interface do not need to be specified since they are
internal to the application program and will not be used by other models, e.g. user-written
models.
3. If no Mechanical Load model is present for a unit, the motor mechanical power (Pmech)
should be held constant at the initial value.
motorAsync - Asynchronous Motor Model
The motorAsynch model represents an asynchrounous (induction) motor with no external
connection to the rotor windings, e.g squirel-cage induction motor.
Model Name
motorAsync
Description
Asynchronous motor model
Parameters:
Parameter
Name
Bus number
Unit ID
MVAbase
kVbase
Rs
Xls
Xs
Xp
Page 42
Usual
Units
MVA
kV
p.u.
p.u.
p.u.
p.u.
CIM
Units??
Typical
Value
MVA
kV
0.005
0.15
1.8
0.5
Description
Terminal bus number in power flow case
Motor (generator) ID in power flow case
MVA base for p.u. values
kV base for p.u. values
Stator resistance (>= 0.)
Stator leakage reactance (> 0.)
Synchronous reactance (>= Xp)
Transient reactance (unsaturated) (> =Xpp)
Xpp
Tpo
Tppo
H (note 2)
p.u.
sec.
sec.
sec.
sec.
sec.
0.2
5.0
0.03
3.0
D (note 3)
S1 (note4)
S12 (note 4)
none
none
none
none
none
none
0.0
0.02
0.12
Sub-transient reactance (unsaturated) (> Xl)
Transient rotor time constant (> Tppo)
Sub-transient rotor time constant (> 0.)
Inertia constant of motor and mechanical load
(> 0.)
Damping factor
Saturation factor at rated term. voltage (>= 0.)
Saturation factor at 120% of rated term.
voltage (>=S1)
1. Motor parameters such as Xl, Xs, etc. are actually used as inductances (L) in the model, but
are commonly referred to as reactances since, at nominal frequency, the per unit values are
the same. However, some references (e.g. PSLF User Manual) use the symbol L instead of
X. Also, the “p” in the parameter names is a substitution for a “prime” in the usual
notation, e.g. Xpp refers to X”.
2. H is the stored energy in the rotating mass of the motor plus its mechanical load and has
units of MW-sec. Conventional units are per unit on the motor MVA base, usually
expressed as MW-sec./MVA or just sec. (since MW and MVA are equivalent units).
3. D has units of power/speed but is regarded as a dimensionless factor resulting from
linearization of an exponential relationship between speed and power: P = Po (ω)D . This
value is often zero when the source of damping torques (damper windings, load damping
effects, etc.) are modeling in detail. [ref]
4. Saturation factors (S1, S12) are defined by S(E1) and S(E2) in Figure genSync1 above.
Model Equations:
The mechanical equations for the motorAsync model can be represented by the following block
diagram:
1.
Te
Pmech
d
n
Σ
n/d
+
Tm _
Σ
1
2Hs
+
+
∆ω
Σ
ω
speed
slip
+
D
Figure motorAsync1 Asynchronous Motor Mechanical Equation Block Diagram
All variables are per unit on motor MVA base except angle, which is in radians. ωo is the system
synchronous frequency in radians per second, e.g. 377. for 60Hz. systems.
Page 43
The electrical equations of the motorAsync model are based on the following equivalent circuit
diagram for the direct and quadrature axes, with two equivalent rotor windings in each axis:
Xls
Rs
Rr1
Rr2
Xlr1
Xlr2
Xm
d axis
q axis – same as d -axis
Figure motorAsync2 Asynchronous Motor Equivalent Circuit
In each axis, the branches represent the stator leakage reactance (Xls) and resistance (Rs), the
magnetizing reactance (Xm), and the equivalent windings (Rr1, Xlr1, etc.) on the rotor.
The relationships between the equivalent circuit parameters and the standard model parameters are
as follows:
Xd = Xm + Xls
Xp = Xls + Xm * Xlr1 / (Xm + Xlr1)
Xpp = Xls + Xm * Xlr1* Xlr2 / (Xm * Xlr1 + Xm * Xlr2 + Xlr1 * Xlr2)
Tpo = (Xm + Xlr1) / (wo * Rr1)
Tppo = (Xm * Xlr1 + Xm * Xlr2 + Xlr1 * Xlr2) / (wo * Rr2 * (Xm + Xlr1)
If Xpp = Xp, a single cage (one equivalent rotor winding per axis) is modeled.
CIM
Model Type
motorAsync
PSLF
Model
motor1
PSS/E
Model
CIMTR2
DigSilent
Model
ElmAsym
Eurostag
Model
A specific block diagram for a motor model is not shown. There will be variations in modeling
among the application programs which should not materially affect the results in the stability
analysis time scale.
Page 44
Voltage Compensation Models
The voltage compensation model adjusts the terminal voltage feedback to the excitation system by
adding a quantity that is proportional to the terminal current of the generator. It is linked to a
specific generator by the Bus number and Unit ID
Model Interconnections
Standard interconnection of voltage compensation models with other models are shown in Figure
B-1 and listed in Table B-1.
Etr, Eti
Network
Itr, Iti
Vc
Voltage Compensation
Excitation
System
Itr2, Iti2
Figure B-1 Voltage Compensation Model Standard Interconnections
Table B-1 Voltage Compensation Model Standard Interconnections
Inputs:
Name
Etr
Eti
Itr
Iti
Itr2
Iti2
Outputs:
Name
Vc
Units
p.u.
p.u.
p.u.
p.u.
p.u.
p.u.
Description
Terminal voltage – real component
Terminal voltage – imaginary component
Terminal current – real component
Terminal current – imaginary component
Terminal current – real component – unit 2
Tterminal current – imaginary component – unit 2
Units
p.u.
Description
Compensated terminal voltage
Initialization Inputs:
Name
Units
Etr
p.u.
Eti
p.u.
Itr
p.u.
Iti
p.u.
Itr2
p.u.
Iti2
p.u.
Initialization Outputs:
Name
Units
Page 45
Description
Terminal voltage – real component
Terminal voltage – imaginary component
Terminal current – real component
Terminal current – imaginary component
Terminal current – real component – unit 2
Tterminal current – imaginary component – unit 2
Description
Source
see note 1
see note 1
see note 1
see note 1
see note 2
see note 2
Source
see note 1
see note 1
see note 1
see note 1
see note 2
see note 2
Vc
p.u.
Compensated terminal voltage
Notes:
1. Source of the generator complex voltage components is application dependent. It may come
from the generator or from the network equations.
2. Unit 2 is a second generator connected to the same terminal bus, usually the other unit of a
cross-compound pair. These inputs are not used by all voltage compensation models.
Page 46
vcompIEEE - IEEE Voltage Compensation Model
Model Name
vcompIEEE
Description
IEEE Voltage Compensation Model
Inputs
Etr, Eti, Itr, Iti
Outputs:
Vc
Parameters:
Parameter
Name
Bus number
Unit ID
Rcomp
Xcomp
Units
Typical
Value
p.u. (gen. base)
p.u. (gen. base)
0.
-0.1
Description
Terminal bus number in power flow case
Generator ID in power flow case
Compensating (compounding) resistance
Compensating (compounding) reactance.
Notes:
.
Equation:
Vcomp = (Etr + jEti ) + (Rcomp + jXcomp ) * (Itr + jIti)
CIM
Model Type
vcompIEEE
PSLF
Model
Rcomp,
Xcomp
PSS/E
Model
IEEEVC
COMP
DigSilent
Model
drp_COMP
Eurostag
Model
Notes:
1. PSLF does not have a separate Voltage Compensator model but permits the specification of
Rcomp and Xcomp (with opposite sign convention) for each generator as part of its generator
model data.
Page 47
vcompCross – Cross-Compound Voltage Compensation Model
Model Name
vcompCross
Description
Voltage Compensation Model for Cross-Compound
Generating Unit
Inputs
Etr, Eti, Itr, Iti, Itr2, Iti2
Outputs:
Vc
Parameters:
Parameter
Name
Bus number
Unit ID
Rcomp
Xcomp
Rcomp2
Xcomp2
Units
Typical
Value
p.u. (gen. base)
p.u. (gen. base)
p.u. (gen. base)
p.u. (gen. base)
0.
-0.1
0.
-0.1
Description
Terminal bus number in power flow case
Generator ID in power flow case
Self-Compensating (compounding) resistance
Self-Compensating (compounding) reactance.
Cross-Compensating (compounding) resistance
Cross-Compensating (compounding) reactance.
Notes:
.
Equation:
Vcomp = (Etr + jEti ) + (Rcomp + jXcomp) * (Itr + jIti) + (Rcomp 2 + jXcomp2) * (Itr 2 + jIti2)
CIM
Model Type
vcompCROSS
PSLF
Model
none
PSS/E
Model
COMPCC
COMCC1
DigSilent
Model
Eurostag
Model
Notes:
1. Equation is based on convention in IEEE Std 421.5-2005. PSS/E model uses a different
convention which can be translated to/from CIM equation coefficients.
2. PSLF does not currently have a standard model for cross compensation.
Page 48
Excitation System Models
The excitation system model provides the field voltage (Efd) for a synchronous machine model. It
is linked to a specific generator by the Bus number and Unit ID. The data parameters are different
for each excitation system model; the same parameter name may have different meaning in
different models.
Model Interconnections
Standard interconnection of excitation system models with other models are shown in Figure C-1
and listed in Table C-1.
VUE L
OEL
VOE L
UEL
Vs
PSS
Vref
Efd
Excitation System
Voltage
Compensator
Vc
Generator
LadIfd
Figure C-1 Excitation System Model Standard Interconnections
Table C-1 Excitation System Model Standard Interconnections
Inputs:
Name
Vc
Vref
Ifd
Vs
Voel
Vuel
Page 49
Units
p.u.
p.u.
p.u.
p.u.
p.u.
p.u.
Description
Compensated generator terminal voltage
Voltage reference
Generator field current
Power system stabilizer (PSS) output
Overexcitation limiter output
Underexcitation limiter output
Source
see note 1
see note 2
Generator
PSS
OEL
UEL
Outputs:
Name
Efd
Units
p.u.
Initialization Inputs:
Name
Units
Efd
p.u.
Ifd
p.u.
Vc
p.u.
Initialization Outputs:
Name
Units
Vref
p.u.
Vs
p.u.
Voel
p.u.
Vuel
p.u.
Description
Generator field voltage
Description
Genator field voltage
Generator field current
Compensated generator terminal voltage
Source
Generator
Generator
Compensator
Description
Voltage Reference
Power system stabilizer (PSS) output – initilialized to zero
Overexcitation limiter output – initialized to large negative value
Underexcitation limiter output – initialized to large positive value
Notes:
1. If a voltage compensation model is present, it is the source of Vc. If not, Vc = Eterm from the
generator model. (Note: PSS/E and PSLF handle compensation differently. In PSS/E, the
compensator is a separate model, which may or may not be present. In PSLF, the
compensating (compounding) impedance values (Rcomp, Xcomp) are included in the generator
data. For CIM, separate compensating model is recommended.)
2. Vref may be modified by a user-written model.
References
Most of the standard excitation system models are based on the 2005 version of the IEEE standard
421.5 “IEEE Recommended Practice for Excitation System Modeling for Power System Stability
Studies”. Earlier versions of this standard in 1992, 1980, and 1968 are also referenced. Nearly all
of the models described in these earlier versions can be adequately represented by models in the
2005 standard. Therefore, separate CIM standard models are not included for those earlier versions
of the models. Legacy models in PSLF and PSS/E based on the earlier versions are still used in
many databases but can translated into the new versions without loss of accuracy.
Page 50
excAC1A - IEEE AC1A Model
Model Name
excAC1A
Description
IEEE (1992/2005) AC1A Model
Parameters:
Parameter
Name
Bus number
Unit ID
Tr
Tb
Tc
Ka
Ta
Vamax
Vamin
Te
Kf
Tf
Kc
Kd
Ke
E1
S(E1)
E2
S(E2)
Vrmax
Vrmin
Units
sec.
sec.
sec.
p.u.
sec.
p.u.
p.u.
sec.
p.u.
sec.
p.u.
p.u.
p.u.
p.u.
none
p.u.
none
p.u.
p.u.
Typical
Value
0.0
0.0
0.0
400.0
0.02
14.5
-14.5
0.8
0.03
1.0
0.20
0.38
1.0
4.18
0.10
3.14
0.03
6.03
-5.43
Description
Terminal bus number in power flow case
Generator ID in power flow case
Filter time constant (>= 0.)
TGR lag time constant (>= 0.)
TGR lead time constant
AVR gain (> 0.)
AVR time constant (> 0.)
Maximum AVR output (> 0.)
Minimum AVR output (< 0.)
Exciter time constant (> 0.)
Rate feedback gain (>= 0.)
Rate feedback time constant (> 0.)
Rectifier regulation factor (>= 0.)
Exciter internal reactance (>= 0.)
Exciter field resistance constant
Field voltage value 1 (note d) (> 0.)
Saturation factor at E1 (note d) (>= 0.)
Field voltage value 2. (note d) (> 0.)
Saturation factor at E2 (note d) (>= 0.)
Maximum exciter control signal (> 0.)
Minimum exciter control signal (< 0.)
Notes:
a) For modeling alternator-rectifier excitation system with non-controlled rectifiers and feedback
from exciter field current, e.g. Westinghouse Brushless system.
b) Ka, Ta, Te, Tf must be non-zero. If Tr or Tb are zero, the respective blocks are bypassed.
c) To disable the forward path gain reduction, set Tb = Tc or set Tb = 0.. To disable the rate
feedback, set Kf = 0.
d) Saturation parameters are consistent with the IEEE saturation factor definition using the open
circuit magnetization of the exciter. Either point [E1, S(E1) or E2, S(E2)] may be the higher
value and the other the lower.
Page 51
Block Diagram:
Vre f
Vc
1 + sTr
-
Σ
-
Vrm a x
Vam ax
+ +
1
V OEL
V U EL
Vs
1 + sTc
Ka
1 + sTb
1+ sTa
Va
HV
Gate
LV
Gate
Vr
+
sTe
-
Π
Efd
Fex
V r m in
V a m in
Ve
1
Σ
0
F( I n )
Vf
In
K e + Se ( Ve )
Vfe
sKf
1+ sTf
Kc Ifd / Ve
+
Σ
+
Kd
Ifd
Model Compatibility:
CIM
Model
excAC1A
PSLF
Model
esac1a
exac1*
PSS/E
Model
ESAC1A
EXAC1*
IEEX2A*
IEET1A*
DigSilent
Model
vco_ESAC1A
Eurostag
Model
vco_IEET1A*
* These models can be represented by excAC1A by setting specific parameters to zero or large
values.
Page 52
excAC2A - IEEE AC2A Model
Model Name
excAC2A
Description
IEEE (1992/2005) AC2A Model (ref)
Parameters:
Parameter
Name
Bus number
Unit ID
Tr
Tb
Tc
Ka
Ta
Vamax
Vamin
Kb
Vrmax
Vrmin
Te
Vfemax
Kh
Kf
Tf
Kc
Kd
Ke
E1
S(E1)
E2
S(E2)
Units
sec.
sec.
sec.
p.u.
sec.
p.u.
p.u.
p.u.
p.u.
p.u.
sec.
p.u.
p.u.
p.u.
sec.
p.u.
p.u.
p.u.
p.u.
none
p.u.
none
Typical
Value
0.0
0.0
0.0
400.0
0.01
8.0
-8.0
25.0
105.0
-95.0
0.6
4.4
1.0
0.03
1.0
0.28
0.35
1.0
4.4
0.037
3.3
0.012
Description
Terminal bus number in power flow case
Generator ID in power flow case
Filter time constant (>= 0.)
TGR lag time constant (>= 0.)
TGR lead time constant
AVR gain (> 0.)
AVR time constant (> 0.)
Maximum AVR output (> 0.)
Minimum AVR output (< 0.)
Exciter field current controller gain (> 0.)
Maximum exciter control signal (> 0.)
Minimum exciter control signal (< 0.)
Exciter time constant (> 0.)
Exciter field current limit parameter (>= 0.)
Exciter field current feedback gain (>= 0.)
Rate feedback gain (>= 0.)
Rate feedback time constant (> 0.)
Rectifier regulation factor (>= 0.)
Exciter internal reactance (>= 0.)
Exciter field resistance constant
Field voltage value 1 (note d) (> 0.)
Saturation factor at E1 (note d) (>= 0.)
Field voltage value 2. (note d) (> 0.)
Saturation factor at E2 (note d) (>= 0.)
Notes:
a) For modeling high initial-response alternator-rectifier excitation system with non-controlled
rectifiers and feedback from exciter field current, e.g. Westinghouse HIR Brushless system.
b) Ka, Kb, Ta, Te, Tf must be non-zero. If Tr or Tb are zero, the respective blocks are
bypassed.
c) To disable the forward path gain reduction, set Tb = Tc or set Tb = 0.. To disable the rate
feedback, set Kf = 0.
Page 53
d) Saturation parameters are consistent with the IEEE saturation factor definition using the open
circuit magnetization of the exciter. Either point [E1, S(E1) or E2, S(E2)] may be the higher
value and the other the lower.
.
e) The upper limit on Ve represents the effect of the field current limiter. If Vfemax is zero, this
limit will not be enforced. The real system, the limiter is implemented by a low value gate just
before Kb. The input to this LV gate is Kl * (Vlr – Vfe). If the values of Kl and Vlr are
known, Vfemax can be calculated as Vlr*Kl*Kb / (1 + Kl*Kb).
Block Diagram:
Vref
Vc
Vs
+ +
1
1 + sTr
-
Ka
Va
1+ sTa
+
1 + sTc
Σ
1 + sTb
-
Va m in
Kb
Σ
Vf e m a x - Kd I f d
K e + Se ( Ve )
VOEL
V U EL]
Va m a x
Vr m a x
HV
Gate
LV
Gate
+
Vh
Vr
1
Σ
-
Π
Ef d
Fex
0
Vr m in
Vf
Ve
sTe
F( I n )
Kh
In
Ke +Se (Ve)
Vf e
sKf
1+ sTf
Kc Ifd / Ve
+
Σ
+
Kd
Ifd
Model Compatibility:
CIM
Model
excAC2A
PSLF
Model
esac2a
exac2*
PSS/E
Model
ESAC2A
EXAC2*
DigSilent
Model
vco_ESAC2A
vco_EXAC2
Eurostag
Model
* exac2a/EXAC2A are based on the 1981 IEEE standard. They can be converted to excAC2A by
computing Vfemax parameter from Vlr, Kl as described in note e above.
Page 54
excAC3A - IEEE AC3A Model
Model Name
excAC3A
Description
IEEE (1992/2005) AC3A Model (ref)
Parameters:
Parameter
Name
Bus number
Unit ID
Tr
Tb
Tc
Ka
Ta
Vamax
Vamin
Te
Vemin
Kr
Kf
Tf
Kn
Efdn
Kc
Kd
Ke
Vfemax
E1
S(E1)
E2
S(E2)
Units
sec.
sec.
sec.
p.u.
sec.
p.u.
p.u.
p.u.
p.u.
p.u.
sec.
p.u.
p.u.
p.u.
sec.
p.u.
p.u.
p.u.
p.u.
none
p.u.
none
Typical
Value
0.0
0.0
0.0
45.62
0.013
1.0
-0.95
1.17
0.84
3.77
0.143
1.0
0.05
2.36
0.104
0.499
1.0
16
6.24
1.143
4.68
0.1
Description
Terminal bus number in power flow case
Generator ID in power flow case
Filter time constant (>= 0.)
TGR lag time constant (>= 0.)
TGR lead time constant
AVR gain (> 0.)
AVR time constant (> 0.)
Maximum AVR output (> 0.)
Minimum AVR output (< 0.)
Exciter time constant (> 0.)
Minimum field voltage limit (<= 0.)
Field self-excitation feedback gain (> 0.)
Low level rate feedback gain (>= 0.)
Rate feedback time constant (> 0.)
High level rate feedback gain (>= 0.)
Rate feedback gain break level (> 0.)
Rectifier regulation factor (>= 0.)
Exciter internal reactance (>= 0.)
Exciter field resistance constant
Exciter field current limit parameter (>= 0.)
Field voltage value 1 (note d) (> 0.)
Saturation factor at E1 (note d) (>= 0.)
Field voltage value 2. (note d) (> 0.)
Saturation factor at E2 (note d) (>= 0.)
Notes:
a) For modeling field-controlled alternator-rectifier excitation system with non-controlled, e.g.
GE Alterrex systems with static voltage regulators.
b) Ka, Kr, Ta, Te, Tf must be non-zero. If Tr or Tb are zero, the respective blocks are bypassed.
c) To disable the forward path gain reduction, set Tb = Tc or set Tb = 0.. To disable the rate
feedback, set Kf = Kn = 0.
Page 55
d) Saturation parameters are consistent with the IEEE saturation factor definition using the open
circuit magnetization of the exciter. Either point [E1, S(E1) or E2, S(E2)] may be the higher
value and the other the lower.
e) The upper limit on Ve is an approximate represention of the effect of the maximum field
current limiter. If Vfemax is zero, this limit will not be enforced. The lower limit (Vemin) on
Ve is an approximate representation of the minimum field voltage limiter. If these limiters are
specified in terms of their basic parameters (Kl1, Kfa, Vlv), the exac3a model should be used.
Block Diagram:
Kr
Vr e f
Vc
Vfem ax - Kd Ifd
Ke + Se ( V e )
Vam ax
V U EL
+
1
1 + sTr
-
1 + sTc
Σ
1 + sTb
HV
G a te
Ka
Σ
+
-
+
Vf
Vs
1+ sTa
X
Va
Vr
+
1
Σ
sTe
-
Ve
Π
Efd
Fex
Va m in
V e m in
F( I n )
Vfe
In
s
1+ sTf
Ke+Se (Ve)
Kc I f d / Ve
+
Σ
+
Kd
Vn
Ifd
Kn
Vn
Kf
Efdn
Efd
Model Compatibility:
CIM
Model
excAC3A
PSLF
Model
esac3a
exac3*
exac3a*
PSS/E
Model
ESAC3A
EXAC3*
DigSilent
Model
vco_ESAC3A
Eurostag
Model
vco_EXAC3A
* exac3/EXAC3 are based on the 1981 IEEE standard and represent the exciter limit differently.
Exac3a represents the exciter limit differently from either exac3 or esac3a. They may be
convertible to excAC3A by computing Vfemax parameter from other model parameters.
Page 56
excAC4A - IEEE AC4A Model
Model Name
excAC4A
Description
IEEE (1992/2005) AC4A Model (ref)
Parameters:
Parameter
Name
Bus number
Unit ID
Tr
Vimax
Vimin
Tc
Tb
Ka
Ta
Vrmax
Vrmin
Kc
Units
sec.
p.u.
p.u.
sec.
sec.
p.u.
sec.
p.u.
p.u.
p.u.
Typical
Value
0.0
10.0
-10.0
1.0
10.0
100.0
0.02
5.64
-4.53
0.0
Description
Terminal bus number in power flow case
Generator ID in power flow case
Filter time constant (>= 0.)
Maximum error signal ( > 0.)
Minimum error signal (< 0.)
Lead time constant
Lag time constant (>= 0.)
Gain (> 0.)
Time constant (> 0.)
Maximum controller output (> 0.)
Minimum controller output (< 0.)
Excitation system regulation (>= 0.)
Notes:
a) This model can be used to represent controlled rectifier systems in which the excitation power
is provided by a voltage-controlled source such as a shaft driven alternator with its own voltage
regulator. The voltage droop of the a.c. excitation power source, if any, and the regulation of
the rectifier are approximated by the parameter, Kc. Do not use this model to represent "busfed" excitation systems.
b) Ka and Ta must be non-zero. If Tr or Tb is zero, the respective block is bypassed.
Block Diagram:
Vr e f
Vc
+
1
1 + sT r
S0
-
1 + sT b
+
Model Compatibility:
Page 57
1 + sT c
Σ
Vs
Vuel
V im a x
V im in
Vr m a x - Kc Ifd
HV
gate
Ka
Efd
1 + sT a
V r m in - K c I f d
CIM
Model
excAC4A
Page 58
PSLF
Model
esac4a
exac4
PSS/E
Model
ESAC4A
EXAC4
DigSilent
Model
vco_ESAC4A
Eurostag
Model
excAC5A - IEEE AC5A Model
Model Name
excAC5A
Description
IEEE (1992/2005) AC5A Model (ref)
Parameters:
Parameter
Name
Bus number
Unit ID
Tr
Ka
Ta
Vrmax
Vrmin
Ke
Te
Kf
Tf1
Tf2
Tf3
E1
Se(E1)
E2
Se(E2)
Units
sec.
p.u.
sec.
sec.
sec.
p.u.
sec.
p.u.
sec.
sec.
sec.
p.u.
none
p.u.
none
Typical
Value
0.0
400.0
0.02
7.3
-7.3
1.0
0.8
0.03
1.0
0.8
0.0
5.6
0.86
4.2
0.5
Description
Terminal bus number in power flow case
Generator ID in power flow case
Filter time constant (>= 0.)
Gain (> 0.)
Time constant (> 0.)
Maximum controller output (> 0.)
Minimum controller output (< 0.)
Exciter field resistance line slope
Exciter time constant, sec. (> 0.)
Rate feedback gain (>= 0.)
Rate feedback lag time constant (> 0.)
Rate feedback lag time constant (>= 0.)
Rate feedback lead time constant
Field voltage value 1 (note c) (> 0.)
Saturation factor at E1 (note c) (>= 0.)
Field voltage value 2. (note c) (> 0.)
Saturation factor at E2 (note c) (>= 0.)
Notes:
a) Simplified model of a brushless, rotating rectifier excitation system.
b) Ka, Ta, Te, Tf1 must be greater than zero. Tr, Tf1, Tf2 may be zero. If Tr is zero, the block
is bypassed.
c) Saturation parameters are given by the IEEE saturation factor definition using the open circuit
magnetization of the exciter. Either point [E1, S(E1) or E2, S(E2)] may be the higher value
and the other the lower .
Block Diagram:
Page 59
Vref
+
Vc
1
1 + sTr
−
Vs
+
Σ
−
Vrmax
Vr
Ka
1 + sTa
+
Σ
−
1
1 + sTe
Efd
Vrmin
Se(Ve) + Ke
sKf (1 + sTf 3)
(1 + sTf1) (1 + sTf 2)
Model Compatibility:
CIM
Model
excAC5A
PSLF
Model
esac5a
exdc2*
PSS/E
Model
ESAC5A
IEEET2
IEEEX2*
DigSilent
Model
vco_ESAC5A
Eurostag
Model
* exdc2 and IEEEX2 have an extra (1+sTc) / (1+sTb) block before the Ka / (1+sTa) block.
They can be converted to excAC5A if Tb = Tc or Tb = 0.
Page 60
excAC6A - IEEE AC6A Model
Model Name
excAC6A
Description
IEEE (1992/2005) AC6A Model (ref)
Parameters:
Parameter
Name
Bus number
Unit ID
Tr
Ka
Ta
Tk
Tb
Tc
Vamax
Vamin
Vrmax
Vrmin
Te
Kh
Tj
Th
Vfelim
Vhmax
Kc
Kd
Ke
E1
S(E1)
E2
S(E2)
Units
sec.
p.u.
sec.
sec.
sec.
sec.
p.u.
p.u.
p.u.
p.u.
sec.
p.u.
sec.
sec.
p.u.
p.u.
p.u.
p.u.
p.u.
p.u.
none
p.u.
none
Typical
Value
0.02
536
0.086
0.18
9.0
3.0
75.0
-75.0
44.0
-36.0
1.0
92.0
0.02
0.08
19.0
75.0
0.173
1.91
1.6
5.55
0.044
7.4
0.214
Description
Terminal bus number in power flow case
Generator ID in power flow case
Filter time constant
Gain (> 0.)
Time constant (>= 0.)
Lag time constant (>= 0.)
Time constant (>= 0.)
Lead time constant
Maximum controller element output (> 0.)
Minimum controller element output (< 0.)
Maximum exciter control signal (> 0.)
Minimum exciter control signal (< 0.)
Exciter time constant (> 0.)
Exciter field current limiter gain (>= 0.)
Field current limiter time constant (>= 0.)
Field current limiter time constant (> 0.)
Exciter field current limit reference (> 0.)
Maximum field current limiter signal (> 0.)
Rectifier regulation factor (>= 0.)
Exciter internal reactance (>= 0.)
Exciter field resistance constant (note c)
Field voltage value 1 (note c) (> 0.)
Saturation factor at E1 (note c) (>= 0.)
Field voltage value 2. (note c) (> 0.)
Saturation factor at E2 (note c) (>= 0.)
Notes:
a) Ka, Te, Th must be non-zero. If Tr, Ta, Tb or Tc is zero, the respective block is bypassed.
b) To disable the forward path gain reduction, set Tb = Tc = 0. This will also disable the nonwindup limits Vamax and Vamin.
c) If Ke = 0., it is set during initialization to make Vr = 0.
Page 61
d) Saturation parameters is given by the IEEE saturation factor definition using the open circuit
magnetization of the exciter. Either point [E1, S(E1) or E2, S(E2)] may be the higher value
and the other the lower.
Block Diagram:
Vuel
Vs
Vc
1 + sTr
+
+
1
−
Vt Vrmax
Va m a x
Ka (1 + sTk)
Σ
1 + sTa
+
1 + sTc
Va
1 + sTb
+
Vr
Σ
+
−
Va m i n
sTe
−
F(In)
0
Vhmax
Se
In
Vil
1 + sTj
Vh
1 + sTh
+
Σ
Kh
−
0
+
Σ
+
+
Σ
+
Ke
Model Compatibility:
Page 62
PSLF
Model
esac6a
exac6a
PSS/E
Model
ESAC6A
Kc Ifd / Ve
Vfe
Vfelim
Kd
CIM
Model
excAC6A
Efd
Π
Fex
Vt Vrmin
Vref
Ve
1
Σ
DigSilent
Model
vco_ESAC6A
Eurostag
Model
Ifd
excAC7B - IEEE AC7B Model
Model Name
excAC7B
Description
IEEE (2005) AC7B Model (ref)
Parameters:
Parameter
Name
Bus number
Unit ID
Tr
Kpr
Kir
Kdr
Tdr
Vrmax
Vrmin
Kpa
Kia
Vamax
Vamin
Kp
Kl
Te
Vfemax
Vemin
Ke
Kc
Kd
Kf1
Kf2
Kf3
Tf
E1
S(E1)
E2
S(E2)
Units
sec.
p.u.
p.u.
p.u.
sec.
p.u.
p.u.
p.u.
p.u.
p.u.
p.u.
p.u.
p.u.
sec.
p.u.
p.u.
p.u.
p.u.
p.u.
p.u.
p.u.
p.u.
sec.
p.u.
none
p.u.
none
Typical
Value
0.0
3.89
3.89
0.0
0.0
6.74
-6.74
117.7
26.8
1.0
-0.95
12.08
10.0
3.0
15.2
0.0
1.0
0.13
1.14
0.194
0.0
0.0
1.0
6.67
1.951
5.0
0.156
Description
Terminal bus number in power flow case
Generator ID in power flow case
Filter time constant (>= 0.)
Regulator proportional gain (> 0. if Kir = 0.)
Regulator integral gain (>= 0.)
Regulator derivative gain (>= 0.)
Derivative gain washout time constant (>= 0.)
Maximum regulator output (> 0.)
Minimum regulator output (< 0.)
Amplifier proportional gain (> 0. if Kia = 0.)
Amplifier integral gain (>= 0.)
Maximum amplifier output (> 0.)
Minimum amplifier output (< 0.)
Exciter field voltage source gain (> 0.)
Exciter field voltage lower limit parameter
Exciter time constant, sec. (> 0.)
Exciter field current limit parameter (note e)
Minimum exciter ouput voltage (<= 0.)
Exciter field resistance constant
Rectifier regulation factor (>= 0.)
Exciter internal reactance (>= 0.)
Field voltage feedback gain (>= 0.)
Exciter field current feedback gain (>= 0.)
Rate feedback gain (>= 0.)
Rate feedback time constant (> 0.)
Field voltage value 1 (note d) (> 0.)
Saturation factor at E1 (note d) (>= 0.)
Field voltage value 2. (note d) (> 0.)
Saturation factor at E2 (note d) (>= 0.)
Notes:
a) For modeling alternator-rectifier excitation system with either stationary or rotating rectifiers
with PID voltage regulator.
Page 63
b) Te and Tf must be non-zero. If Tr or Tdr are zero, the respective blocks are bypassed. Kpa
and Kpi must not be zero if their corresponding integral gains are zero.
c) To disable the rate feedback, set Kf3 = 0.
d) Saturation parameters are consistent with the IEEE saturation factor definition using the open
circuit magnetization of the exciter. Either point [E1, S(E1) or E2, S(E2)] may be the higher
value and the other the lower.
e) The upper limit on Ve represents the effect of the field current limiter. If Vfemax is zero, this
limit will not be enforced.
f) In the IEEE Std 421.5 – 2005 document, the 1. / sTe block in the block diagram below is
shown as 1. / (1 + sTE), which is incorrect
Block Diagram:
Kp V t
+
Vc
1
1 + sTr
Vs
Vr e f
Vu e l
-
+
+
Σ
Kpr +
-
Kir
s
+
s Kdr
1+ sTdr
Vf e m a x - K d I f d
K e + S e ( Ve )
Va m a x
Vr m a x
+
Kpa +
Σ
-
Kia
s
Va
Vr
Π
+
sTe
-
Σ
F( I n )
Kf 2
In
+
Ke+Se(Ve )
Vfe
s Kf 3
1+ sTf
Σ
+
Kf 1
Model Compatibility:
Page 64
PSLF
Model
esac7b
Kc I f d / Ve
+
Kd
CIM
Model
excAC7B
Ef d
V e m in
Va m in
+
Π
Fex
- Kl V f e
V r m in
Vf
Ve
1
Σ
PSS/E
Model
ESAC7B
DigSilent
Model
Eurostag
Model
Ifd
excAC8B - IEEE AC8B Model
Model Name
excAC8B
Description
IEEE (2005) AC8B Model (ref)
Parameters:
Parameter
Name
Bus number
Unit ID
Tr
Kpr
sec.
p.u.
0.0
80.0
Kir
Kdr
Tdr
p.u.
p.u.
sec.
5.0
10.0
0.1
Vrmax
Vrmin
Ka
Ta
Te
Vfemax
Vemin
Ke
Kc
Kd
E1
S(E1)
E2
S(E2)
vtmult
p.u.
p.u.
p.u.
sec.
sec.
p.u.
p.u.
p.u.
p.u.
p.u.
p.u.
none
p.u.
none
none
35.0
0.0
1.
0.0
1.2
6.0
0.0
1.0
0.55
1.1
6.5
0.3
9.0
3.0
0.
Units
Typical
Value
Description
Terminal bus number in power flow case
Generator ID in power flow case
Voltage transducer time constant (>= 0.)
Voltage Regulator Proportional Gain (> 0. if
Kir = 0.)
Voltage Regulator Integral Gain (>= 0.)
Voltage Regulator Derivative Gain (>= 0.)
Voltage Regulator Derivative Time Constant
(> 0. if Kdr > 0.)
Maximum controller output (> 0.)
Minimum controller output (<= 0.)
Amplifier gain (> 0.)
Amplifier time constant (>= 0.)
Exciter field time constant (> 0.)
Exciter field current limit parameter (note d)
Minimum exciter ouput voltage (<= 0.)
Exciter field proportional constant
Rectifier regulation factor (>= 0.)
Exciter regulation factor (>= 0.)
Field voltage value 1 (note c) (> 0.)
Saturation factor at E1 (note c) (>= 0.)
Field voltage value 2. (note c) (> 0.)
Saturation factor at E2 (note c) (>= 0.)
if not 0, multiply Vrmax and Vrmin by
terminal voltage (note e)
Notes:
a) This model represents a PID voltage regulator with either a brushless exciter or dc exciter. For
a dc exciter, Kc and Kd are set to zero.
b) Te must be non-zero. If Tr is zero, the block is bypassed. If Ta is zero, the block is reduced to
multiplication by Ka. If Tdr is zero, the output of the derivative block is set to zero. Kpr
must not be zero if Kir is zero.
Page 65
c) Saturation parameters are consistent with the IEEE saturation factor definition using the open
circuit magnetization of the exciter. Either point [E1, S(E1) or E2, S(E2)] may be the higher
value and the other the lower.
d) The upper limit on Ve represents the effect of the field current limiter. If Vfemax is zero, this
limit will not be enforced.
e) If vtmult is non-zero, the limits Vrmax and Vrmin are multiplied by the generator’s terminal
voltage to represent a thyristor power stage fed from the generator terminals. This parameter is
not in the IEEE standard model.
Block Diagram:
Vre f
Kp r
+
Vc
1
1 + sTr
+
Kir
Σ
-
s
Σ
+
+
+
sKdr
1 + sTdr
Vs
Vfe m a x - Kd Ifd
K e + S e ( Ve )
Vr m a x
Ka
1 + sTa
V r m in
Vr
+
1
sTe
Σ
-
V emi n
Ife
Ve
Π
Efd
Fex
F (In)
In
Σ
Ke + Se
+
+
Kc Ifd
Ve
Ifd
Kd
Model Compatibility:
CIM
Model
excAC8B
PSLF
Model
esac8b
PSS/E
Model
ESAC8B*
DigSilent
Model
vco_ESAC8B
Eurostag
Model
* As of rev. 30, ESAC8B in PSS/E did not have the parameters Kc, Kd, Vfemax, Vemin of
the IEEE model. Therefore, it can represent a dc exciter but not an ac/rectifier exciter.
Page 66
excDC1A - IEEE DC1A Model
Model Name
excDC1A
Description
IEEE (1992/2005) DC1A Model (ref)
Parameters:
Parameter
Name
Bus number
Unit ID
Tr
Ka
Ta
Tb
Tc
Vrmax
Vrmin
Ke
Te
Kf
Tf
E1
S(E1)
E2
S(E2)
uelin
sec.
p.u.
sec.
sec.
sec.
p.u.
p.u.
p.u.
sec.
p.u.
sec.
p.u.
none
p.u.
none
none
0.0
40.0
0.1
0.0
0.0
1.0
-1.0
0.1
0.5
0.05
0.7
2.8
0.08
3.7
0.33
0
exclim
none
0
Units
Typical
Value
Description
Terminal bus number in power flow case
Generator ID in power flow case
Filter time constant (>= 0.)
Gain (> 0.)
Time constant (> 0.)
Lag time constant (>= 0.)
Lead time constant
Maximum controller output (note d)
Minimum controller output (< 0.)
Exciter field resistance line slope (note c)
Exciter time constant (> 0.)
Rate feedback gain (>= 0.)
Rate feedback time constant, sec. (> 0.)
Field voltage value 1 (note e) (> 0.)
Saturation factor at E1 (note e) (>= 0.)
Field voltage value 2. (note e) (> 0.)
Saturation factor at E2 (note e) (>= 0.)
UEL input: if < 2, HV gate; if = 2, add to error
signal
If not 0, apply lower limit of 0. to exciter
output (note f)
Notes:
a) Ka, Ta, and Te, must be greater than zero. If Tr, Tb or Tf are zero, the respective blocks are
bypassed.
b) To disable the forward path gain reduction, set Tb = Tc or set Tb = 0.. To disable the rate
feedback, set Kf = 0.
c) If Ke is entered as zero, the model calculates an effective value of Ke such that the initial
condition value of Vr is zero. The zero value of Ke is not changed. If Ke is entered as nonzero, its value is used directly, without change.
Page 67
d) If Vrmax <= 0., an effective maximum control value of Vrmax is determined, such that the
control signal, Vr, has the value Vrmax when the exciter output is equal to E2.
e) Saturation parameters is given by the IEEE saturation factor definition using the open circuit
magnetization of the exciter. Either point [E1, S(E1) or E2, S(E2)] may be the higher value
and the other the lower value if the input value of Vrmax > 0; else E2 must > E1.
f) IEEE standard is ambiguous about lower limit on exciter output. If exclim is set non-zero, a
lower limit of zero is applied to integrator output.
Block Diagram:
Vref
Vc
uel i n = 2
+
Vs
1 + sTc
1 + sTb
Σ
−
uel i n < 2
Vrm a x
+
+
1
1 + sTr
V U EL
HV
G a te
Ka
1 + sTa
−
Vr
+
Σ
−
V r m in
Vf
1
sTe
Efd
(no te f)
Se + Ke
sKf
1 + sTf
Model Compatibility:
CIM
Model
excDC1A
PSLF
Model
esdc1a
exdc1*
ieeet1*
PSS/E
Model
ESDC1A
IEEEX1*
IEEET1*
DigSilent
Model
vco_ESDC1A
vco_IEEEX1
vco_IEEET1
Eurostag
Model
* These models are based on early versions of the IEEE standard and can be converted to
the excDC1A model without loss of data.
Page 68
excDC2A - IEEE DC2A Model
Model Name
excDC2A
Description
IEEE (1992/2005) DC2A Model (ref)
Parameters:
Parameter
Name
Bus number
Unit ID
Tr
Ka
Ta
Tb
Tc
Vrmax
Vrmin
Ke
Te
Kf
Tf
E1
S(E1)
E2
S(E2)
uelin
sec.
p.u.
sec.
sec.
sec.
p.u.
p.u.
p.u.
sec.
p.u.
sec.
p.u.
none
p.u.
none
none
0.0
300.0
0.01
0.0
0.0
4.95
-4.9
1.0
1.33
0.1
0.675
3.05
0.279
2.29
0.117
0
exclim
none
0
Units
Typical
Value
Description
Terminal bus number in power flow case
Generator ID in power flow case
Filter time constant (>= 0.)
Gain (> 0.)
Time constant (> 0.)
Lag time constant (>= 0.)
Lead time constant
Maximum controller output (note d)
Minimum controller output (< 0.)
Exciter field resistance line slope (note c)
Exciter time constant (> 0.)
Rate feedback gain (>= 0.)
Rate feedback time constant, sec. (> 0.)
Field voltage value 1 (note e) (> 0.)
Saturation factor at E1 (note e) (>= 0.)
Field voltage value 2. (note e) (> 0.)
Saturation factor at E2 (note e) (>= 0.)
UEL input: if < 2, HV gate; if = 2, add to error
signal
If not 0, apply lower limit of 0. to exciter
output (note f)
Notes:
a) Ka, Ta, and Te, must be greater than zero. If Tr or Tb is zero, the respective block is
bypassed. If Tf is zero, the rate feedback block is not used.
b) To disable the forward path gain reduction, set Tb = Tc or set Tb = 0.. To disable the rate
feedback, set Kf = 0 or Tf = 0.
c) If Ke is entered as zero, the model calculates an effective value of Ke such that the initial
condition value of Vr is zero. The zero value of Ke is not changed. If Ke is entered as nonzero, its value is used directly, without change.
Page 69
d) If Vrmax <= 0., an effective maximum control value of Vrmax is determined, such that the
control signal, Vr, has the value Vrmax when the exciter output is equal to E2.
e) Saturation parameters are given by the IEEE saturation factor definition using the open circuit
magnetization of the exciter. Either point [E1, S(E1) or E2, S(E2)] may be the higher value
and the other the lower value if the input value of Vrmax > 0; else E2 must > E1.
f) IEEE standard is ambiguous about lower limit on exciter output. If exclim is set non-zero, a
lower limit of zero will be applied to integrator output.
Block Diagram:
Vref
Vc
uel i n = 2
+
Vs
1 + sTc
1 + sTb
Σ
−
uel i n < 2
Vt * Vrm a x
+
+
1
1 + sTr
V U EL
HV
G a te
Ka
1 + sTa
Vr
+
−
V t * V r m in
Vf
Σ
−
1
sTe
Efd
(no te f)
Se + Ke
sKf
1 + sTf
Model Compatibility:
CIM
Model
excDC2A
PSLF
Model
esdc2a
exdc2a*
PSS/E
Model
EXDC2A
EXDC2*
DigSilent
Model
Eurostag
Model
* These models are based on early versions of the IEEE standard and can be converted to
the excDC2A model without loss of data.
Page 70
excDC3A - IEEE DC3A Model
Model Name
excDC3A
Description
IEEE (1992/2005) DC3A Model (ref)
Parameters:
Parameter
Name
Bus number
Unit ID
Tr
Trh
Kv
sec.
sec.
p.u.
0.0
20.0
0.05
Vrmax
Vrmin
Te
Ke
E1
S(E1)
E2
S(E2)
exclim
p.u.
p.u.
sec.
p.u.
p.u.
none
p.u.
none
none
5.0
0.0
1.83
1.0
2.6
0.1
3.45
0.35
0
Units
Typical
Value
Description
Terminal bus number in power flow case
Generator ID in power flow case
Filter time constant (>= 0.)
Rheostat full range travel time (> 0.)
Voltage error threshold min/max control action
(> 0.)
Maximum control element output (> 0.)
Minimum control element output (<= 0.)
Exciter field time constant (> 0.)
Exciter field resistance line slope (note b)
Field voltage value 1 (note c) (> 0.)
Saturation factor at E1 (note c) (>= 0.)
Field voltage value 2. (note c) (> 0.)
Saturation factor at E2 (note c) (>= 0.)
If not 0, apply lower limit of 0. to exciter
output (note d)
Notes:
a) Kv, Trh and Te must be greater than zero.
b) If Ke is entered as zero, the model calculates an effective value of Ke such that the initial
condition value of Vr is zero. The zero value of Ke is not changed. If Ke is entered as nonzero, its value is used directly, without change.
c) Saturation parameters are given by the IEEE saturation factor definition using the open circuit
magnetization of the exciter. Either point [E1, S(E1) or E2, S(E2)] may be the higher value
and the other the lower.
d) IEEE standard is ambiguous about lower limit on exciter output. If exclim is set non-zero, a
lower limit of zero will be applied to integrator output.
Block Diagram:
Page 71
Vre f
Vrmax
Vc
Kv
+
1
1 + sTr
−
Σ
Verr
Vrmax −Vrmin
s Kv Trh
−Kv
Vrmin
If V err ≥ K v , Vr = Vr max
If V err ≤ −K v , Vr = Vr min
else Vr = Vrh
Vx = Efd Se(Efd)
Vx
Vrh
Vr −
+
Σ
1
Ke + STe
(note d)
Model Compatibility:
CIM
Model
excDC3A
PSLF
Model
esdc3a
exdc4*
PSS/E
Model
IEEEX4
DigSilent
Model
* exdc4 with it’s parameter Kr = 0 is the same as excDC3A
Page 72
Eurostag
Model
Efd
excDC4B - IEEE DC4B Model
Model Name
excDC4B
Description
IEEE (2005) DC4B Model
Parameters:
Parameter
Name
Bus number
Unit ID
Tr
Ka
Ta
Kp
Ki
Kd
Td
Vrmax
Vrmin
Ke
Te
Kf
Tf
E1
S(E1)
E2
S(E2)
Vemin
OELin
sec.
p.u.
sec.
p.u.
p.u.
p.u.
sec.
p.u.
p.u.
p.u.
sec.
p.u.
sec.
p.u.
none
p.u.
none
p.u.
none
0.0
1.0
0.2
80
20
20
0.01
6.0
-2.7
1.0
0.8
0.0
0.0
1.75
0.08
2.33
0.27
0.
0
UELin
none
0
Units
Typical
Value
Description
Terminal bus number in power flow case
Generator ID in power flow case
Filter time constant (>= 0.)
Gain (> 0.)
Time constant (> 0.)
Proportional gain (>= 0.)
Integral gain (>= 0.)
Derivative gain (>= 0.)
Derivative time constant (> 0. If Kd > 0.)
Maximum controller output (note d)
Minimum controller output (<= 0.)
Exciter field resistance line slope (note c)
Exciter time constant (> 0.)
Rate feedback gain (>= 0.)
Rate feedback time constant (>= 0.)
Field voltage value 1 (note e) (> 0.)
Saturation factor at E1 (note e) (>= 0.)
Field voltage value 2. (note e) (> 0.)
Saturation factor at E2 (note e) (>= 0.)
Exciter minimum output (<= 0.)
OEL input: if < 2, LV gate; if = 2, subtract
from error signal
UEL input: if < 2, HV gate; if = 2, add to error
signal
Notes:
a) Ka, Ta, and Te, must be greater than zero. If Tr is zero, the block is bypassed. If Td or Tf are
zero, the respective blocks are not used.
b) To disable the derivative path, set Kd = 0 or set Td = 0.. To disable the rate feedback, set Kf =
0.
Page 73
c) If Ke is entered as zero, the model calculates an effective value of Ke such that the initial
condition value of Vc is zero. The zero value of Ke is not changed. If Ke is entered as nonzero, its value is used directly, without change.
d) If Vrmax <= 0., an effective maximum control value of Vrmax is determined, such that the
control signal, Vc, has the value Vrmax when the exciter output is equal to E2.
e) Saturation parameters are given by the IEEE saturation factor definition using the open circuit
magnetization of the exciter. Either point [E1, S(E1) or E2, S(E2)] may be the higher value
and the other the lower value if the input value of Vrmax > 0; else E2 must > E1.
Block Diagram:
oel i n = 2
uel i n = 2
Vref
Vc
1
1 + sTr
−
+
Vs
[vsig]
+
Σ
oel i n < 2
uel i n < 2
Vt
Vrm a x / Ka
−
+
V U EL
V OEL
Kpr +
Kir
s
+
s Kdr
1+ sTdr
Vt Vrm a x
HV
G a te
LV
G a te
Π
Ka
1 + sTa
−
Vf
Vr
+
Σ
−
V t V r m in
V r m in / K a
1
sTe
(note g)
Se + Ke
sKf
1 +S4sTf
Model Compatibility:
CIM
Model
excDC4B
PSLF
Model
esdc4b
** Not in PSS/E as of rev. 30
Page 74
PSS/E
Model
**
DigSilent
Model
Eurostag
Model
Efd
excST1A - IEEE ST1A Model
Model Name
excST1A
Description
IEEE (1992/2005) ST1A Model
Parameters:
Parameter
Name
Bus number
Unit ID
Tr
Vimax
Vimin
Tc
Tb
Ka
Ta
Vrmax
Vrmin
Kc
Kf
Tf
Tc1
Tb1
Vamax
Vamin
Ilr
Klr
UELin
sec.
p.u.
p.u.
sec.
sec.
p.u.
sec.
p.u.
p.u.
p.u.
p.u.
sec.
sec.
sec.
p.u.
p.u.
p.u.
p.u.
none
0.0
999.
-999.
1.0
10.0
190.0
.02
7.8
-6.7
0.05
0.0
1.0
0.0
0.0
999.
-999.
0.0
0.0
0
PSSin
none
0
Units
Typical
Value
Description
Terminal bus number in power flow case
Generator ID in power flow case
Voltage transducer time constant (>= 0.)
Maximum error (> 0.)
Minimum error (< 0.)
Lead time constant
Lag time constant (>= 0.)
Gain (> 0.)
Time constant (>= 0.)
Excitation voltage upper limit (> 0.)
Excitation voltage lower limit (< 0.)
Excitation system regulation factor (>= 0.)
Rate feedback gain (>= 0.)
Rate feedback time constant (>= 0.)
Lead time constant
Lag time constant (>= 0.)
Maximum control element output (> 0.)
Minimum control element output (< 0.)
Maximum field current (note b)
Gain on field current limit (note b)
= 2 – UEL input added to error signal
= 1 – UEL input HV gate with error signal
= -1 – UEL input HV gate with volt. reg.
output
= 0 – ignore UEL signal
= 0 – PSS input (Vs) added to error signal
≠ 0 – PSS input (Vs) added to voltage
regulator output
Notes:
a) This model can be used to represent a controlled-rectifier excitation system whose a.c. power
source is a power transformer fed from the generator terminals. The voltage regulation of the
excitation transformer and rectifier are approximated by the parameter Kc.
Page 75
b) The field current limiter (Klr, Ilr) is optional. If Klr = 0., the limiter is not used.
c) Ka and Ta must not be zero. If Ta, Tr, Tb, or Tb1 are zero, the corresponding block is
bypassed. If Tf is zero, the output of the rate feedback block is zero.
Block Diagram:
V U EL
Vs
ps s i n = 0
Vc
1
1 + sTr −
Vs
Σ
+
V U EL
ps sin ≠ 0
uel i n = 1
Vimax
+
+
VU EL
uel i n = 2
uel i n = - 1
Vt Vrm ax - Kc Ifd
Vam a x
HV
Gate
1 + sTc
1 + sTb
1 + sTc1
1 + sTb1
Ka
Va
1 + sTa
−
+
+
HV
Gate
Σ
LV
Gate
V a m in
Ef d
Vt V r m in
Vref
Voel
sKf
+ sTf
Klr
Σ
+
•
−
0
I lr
Model Compatibility:
PSLF
Model
esst1a
exst1*
PSS/E
Model
ESST1A
EXST1*
DigSilent
Model
vco_ESST1A
vco_EXST1
Eurostag
Model
* Based on earlier (1981) IEEE standard. Can be converted to excST1A.
Page 76
•
−
Vimin
CIM
Model
excST1A
Ve
lf d
excST2A - IEEE ST2A Model
Model Name
excST2A
Description
IEEE (1992/2005) ST2A Model
Parameters:
Parameter
Name
Bus number
Unit ID
Tr
Ka
Ta
Vrmax
Vrmin
Ke
Te
Kf
Tf
Kp
Ki
Kc
Efdmax
UELin
Tb
Tc
Units
sec.
p.u.
sec.
p.u.
p.u.
p.u.
sec.
p.u.
sec.
p.u.
p.u.
p.u.
p.u.
none
sec.
sec.
Typical
Value
0.0
120.0
0.15
1.0
-1.0
1.0
0.5
0.05
0.7
4.88
8.0
1.82
99.0
0
0.0
0.0
Description
Terminal bus number in power flow case
Generator ID in power flow case
Filter time constant (>= 0.)
Gain (> 0.)
Time constant (> 0.)
Maximum controller output (> 0.)
Minimum controller output (< 0.)
Time constant feedback
Transformer saturation control time constant (> 0.)
Rate feedback gain (>= 0.)
Rate feedback time constant (>= 0.)
Potential source gain (>= 0.)
Current source gain (>= 0.)
Rectifier loading factor (>= 0.)
Maximum field voltage (>=0.)
UEL input: if = 1, HV gate; if = 2, add to error signal
Time constant (>=0.) (note b)
Time constant (note b)
Notes:
a) Ka, Ta, Te must be greater than zero. If Tr or Tb are zero, the respective blocks are bypassed.
If Tf is zero, the rate feedback is disabled.
b) The lead/lag block (Tc, Tb), which is not in the IEEE ST2A model, is included to match the
WECC FM exciter model. The block can be bypassed by omitting these parameters or by
setting Tb to zero.
Block Diagram:
Page 77
Vs
V U EL
uel i n = 1
uel i n = 2
+
Vc
1
1 + sTr
−
+
Σ
+
1 + sTc
1 + sTb
−
Vrmax
HV
Gate
Ka
1 + sTa
Efdmax
Vr
Vb
Vrmin
Vref
+
Π
1
sTe
Σ
−
Efd
0
Ke
skf
1 + sTf
•
Ifd
Vt
Ve = K p Vt + jK i It
It
Ve
•
Π
Fex(In)
In
Kc Ifd / Ve
Model Compatibility:
CIM
Model
excST2A
PSLF
Model
esst2a
exst2*
exst2a*
PSS/E
Model
ESST2A
EXST2*
EXST2A*
IEEEX3*
IEEET3*
DigSilent
Model
vco_ESST2A
Eurostag
Model
vco_EXST2A
* Based on earlier IEEE standards. Can be converted to excST2A.
Page 78
excST3A - IEEE ST3A Model
Model Name
excST3A
Description
IEEE (1992/2005) ST3A Model
Parameters:
Parameter
Name
Bus number
Unit ID
Tr
Vimax
Vimin
Ka
Ta
Tb
Tc
Vrmax
Vrmin
Km
Tm
Vmmax
Vmmin
Kg
Kp
angp
Ki
Kc
Xl
Vbmax
Vgmax
Units
sec.
p.u.
p.u.
p.u.
sec.
sec.
sec.
p.u.
p.u.
p.u.
sec.
p.u.
p.u.
p.u.
p.u.
deg..
p.u.
p.u.
p.u.
p.u.
p.u.
Typical
Value
0.0
0.2
-0.2
200.
0.0
6.67
1.0
10.0
-10.0
7.04
1.0
1.0
0.0
1.0
4.37
20.0
4.83
1.1
0.09
8.63
6.53
Description
Terminal bus number in power flow case
Generator ID in power flow case
Voltage transducer time constant (>= 0.)
Maximum error (> 0.)
Minimum error (< 0.)
AVR gain (> 0.)
AVR time constant (>= 0.)
AVR lag time constant (>= 0.)
AVR lead time constant
Maximum AVR output (> 0.)
Minimum AVR output (< 0.)
Inner loop forward gain (> 0.)
Inner loop time constant (> 0.)
Maximum inner loop output (> 0.)
Minimum inner loop output (<= 0.)
Inner loop feedback gain (>= 0.)
Potential source gain (> 0.)
Phase angle (θp) of potential source
Current source gain (>= 0.)
Exciter regulation factor (>= 0.)
P-bar reactance (>= 0.)
Maximum excitation voltage (> 0.)
Maximum inner loop feedback voltage (>= 0.)
Notes:
c) Ka, Km and Tm must be greater than zero. If Tr, Ta or Tb is zero, the corresponding block
are bypassed
Block Diagram:
Page 79
Vgmax
Kg
Vuel
Vref
Vimax
Vc
1
1 + sTr
+
−
Vi
Σ
Vmmax
Vrmax
HV
Gate
Vr
Ka
1 + sTa +
1 + sTc
1 + sTb
−
Vm
Km
1 + sTm
Σ
•
Π
Efd
+
Vimin
Vrmin
Vbmax
Vmmin
Vb
Vs
Vt
Kp Vt + j(K i + Kp Xl ) It
It
Ve
•
Π
Fex (In)
In
Ifd
Kc Ifd / Ve
jθ
Kp = K p e p
Model Compatibility:
CIM
Model
excST3A
PSLF
Model
esst3a
exst3*
exst3a*
PSS/E
Model
ESST3A
DigSilent
Model
vco_ESST3A
EXST3A*
* Based on earlier IEEE standard. Can be converted to excST3A.
Page 80
Eurostag
Model
excST4B - IEEE ST4B Model
Model Name
excST4B
Description
IEEE (2005) ST4B Model
Parameters:
Parameter
Name
Bus number
Unit ID
Tr
Kpr
Kir
Ta
Vrmax
Vrmin
Kpm
Kim
Vmmax
Vmmin
Kg
Kp
Angp
Ki
Kc
Xl
Vbmax
Vgmax
Units
sec.
p.u.
p.u.
sec.
p.u.
p.u.
p.u.
p.u.
p.u.
p.u.
p.u.
p.u.
deg..
p.u.
p.u.
p.u.
p.u.
p.u.
Typical
Value
0.0
10.75
10.75
0.02
1.0
-0.87
1.0
0.0
99.
-99.
0.0
9.3
0.0
0.0
0.113
0.124
11.63
999.
Description
Terminal bus number in power flow case
Generator ID in power flow case
Voltage transducer time constant (>= 0.)
AVR proportional gain (note b)
AVR Integral gain (note b)
AVR time constant (>= 0.)
Maximum AVR output (> 0.)
Minimum AVR output (< 0.)
Prop. gain of inner loop regulator (note a)
Integral gain of inner loop regulator (note a)
Maximum inner loop regulator output
Minimum inner loop regulator output
Inner loop feedback gain (>= 0.)
Potential source gain (> 0.)
Phase angle (θp) of potential source
Current source gain (>= 0.)
Exciter regulation factor (>= 0.)
P-bar leakage reactance (>= 0.)
Maximum excitation voltage (> 0.)
Maximum inner loop feedback gain (>= 0.)
Notes:
a) The inner loop field voltage regulator parameters (Kpm, Kim and Kg) are used for modeling of
a compound power source static exciter. Any of these values can be zero, but either Kpm or
Kim must be non-zero. To bypass the inner loop field voltage regulator, set Kpm = 1.0, and
Kim and Kg to zero.
b) Either of the automatic voltage regulator AVR parameters (Kpr, Kir) may be zero but at least
one must be non-zero.
c) Setting Ta or Tr to zero will bypass the corresponding block. If Ta is zero, a one time step
delay is included for this block.
Page 81
Block Diagram:
Vgmax
Kg
Vref
Vuel
Vc
1
1 + sTr
Vrmax
+ +
−
Voel
[voel]
Kpr +
Σ
Kir
s
+
Vr
1
1 + sTa
Vmmax
−
+
Σ
Vrmin
Kpm +
Kim
s
Vm
Vmmin
LV
Gate
•
Π
Efd
Vb
Vbmax
Vs
Vt
Kp Vt + j(K i + Kp Xl ) It
It
Ve
•
Π
In
Fex (In)
Ifd
Kc Ifd / Ve
jθ
Kp = K p e p
Model Compatibility:
CIM
Model
excST4B
PSLF
Model
esst4b
exst4b*
*. Can be converted to excST4B.
Page 82
PSS/E
Model
ESST4B
DigSilent
Model
vco_ESST4B
Eurostag
Model
excST5B - IEEE ST5B Model
Model Name
excST5B
Description
IEEE (2005) ST5B Model
Parameters:
Parameter
Name
Bus number
Unit ID
Tr
Kr
T1
Kc
Vrmax
Vrmin
Tc1
Tb1
Tc2
Tb2
Toc1
Tob1
Toc2
Tob2
Tuc1
Tub1
Tuc2
Tub2
Units
sec.
p.u.
p.u.
p.u.
p.u.
p.u.
sec.
sec.
sec.
sec.
sec.
sec.
sec.
sec.
sec.
sec.
sec.
sec.
Typical
Value
0.0
200
0.004
0.004
5.0
-4.0
0.8
6.0
0.08
0.01
0.1
2.0
0.08
0.08
2.0
10.0
0.1
0.05
Description
Terminal bus number in power flow case
Generator ID in power flow case
Filter time constant (>= 0.)
Regulator gain (> 0.)
Firing circuit time constant (>= 0.)
Rectifier regulation factor (>= 0.)
Maximum regulator output (> 0.)
Minimum regulator output (< 0.)
Regulator lead time constant
Regulator lag time constant (>= 0.)
Regulator lead time constant.
Regulator lag time constant (>= 0.)
OEL lead time constant
OEL lag time constant (>= 0.)
OEL lead time constant
OEL lag time constant (>= 0.)
UEL lead time constant.
UEL lag time constant (>= 0.)
UEL lead time constant
UEL lag time constant (>= 0.)
Notes:
a) For modeling static systems such as ABB UNITROL D, P, F, or 5000 or Brush DCP. Similar
to IEEE Type ST1A but with alternative OEL and UEL inputs and transfer functions.
b) Kr must not be zero. Any of the time constants may be zero. If any denominator time constant
is zero, the respective block is bypassed.
c) If T1 is less than 4 times the integration time step, it’s block is replaced by a one time step
delay.
Block Diagram:
Page 83
Vrmax/Kr
1+sToc1
1+sTob1
Vrmin/Kr
Vrmax /Kr
1+sToc2
1+sTob2
if (Voel < Verr, jlim = +1
if (Vuel > Verr, jlim = -1
else jlim = 0
Vrmin/Kr
Vref
Voel
Vc
1
1 + sTr
S0
+
−
Σ
Vuel
Ver
r
Vrmax/Kr
LV
Gate
HV
Gate
+
Σ
•
+
Vs
1+sTc1
1+sTc2
1+sTb1
Vrmin/Kr
1+sTub1
Vrmin/Kr
0
1+sTb2
Vrmin/Kr
Vrmax/Kr
1+sTuc1
Vrmax
Vrmax/Kr
+1
• jlim
Kr
−1
Vrmin
Vr
+
−
Vt Vrmax
1
Σ
Vt Vrmin
Kc
Vrmax/Kr
1+sTuc2
1+sTub2
Vrmin/Kr
Model Compatibility:
CIM
Model
excST5B
PSLF
Model
esst5b
**. As of rev. 30, not in PSS/E.
Page 84
PSS/E
Model
**
DigSilent
Model
Efd
1 + sT1
Eurostag
Model
Ifd
excST6B - IEEE ST6B Model
Model Name
excST6B
Description
IEEE (2005) ST6B Model
Parameters:
Parameter
Name
Bus number
Unit ID
Tr
Kpa
Kia
Vamax
Vamin
Kff
Km
Kg
Tg
Vrmax
Vrmin
Vmult
OELin
sec.
p.u.
p.u.
p.u.
p.u.
p.u.
p.u.
p.u.
sec.
p.u.
p.u.
none
none
0.012
18.
45.
4.81
-3.85
1.0
1.0
1.0
0.02
4.81
-3.85
1.0
0.0
Ilr
Kcl
Klr
Ts
p.u.
p.u.
p.u.
sec.
4.164
1.0577
17.33
0.0
Units
Typical
Value
Description
Terminal bus number in power flow case
Generator ID in power flow case
Filter time constant (>= 0.)
Regulator proportional gain (> 0.)
Regulator integral gain (> 0.)
PI maximum output. (> 0.)
PI minimum output (< 0.)
Feedforward gain (note b)
Main gain (note b)
Feedback gain (>= 0.)
Feedback time constant (>= 0.)
Maximum regulator output (> 0.)
Minimum regulator output (< 0.)
If non-zero, multiply regulator output by terminal voltage
OEL input selector: 1 – before UEL, 2 – after UEL, 0 – no
OEL input
Field current limiter setpoint (> 0.)
Field current limiter conversion factor (> 0.)
Field current limiter gain (> 0.)
Rectifier firing time constant (not in IEEE model) (>= 0.)
Notes:
a) For modeling static systems such as Siemens THYRIPOL or ECS2100.
b) Kpa and Kia must not be zero. (Kff + Km) must not be zero. Any of the time constants may
be zero. If any time constant is zero, the respective block is bypassed.
c) If Ts is less than 4 times the integration time step, its block is replaced by a one time step
delay.
Block Diagram:
Page 85
Ilr
Kcl
+
Σ
−
Ifd
Vt
Klr
VOEL OELin=2
OELin=1
1
1 + sTr
−
Vrmin
Kff
−
−
Vc
Vamax
Σ
+
Vref
+
HV
Gate
Σ
Kpa +
+
Kia
s
Va
•
+
Σ
Km
+
−
Vrmax
Σ
LV
Gate
Vrmin
Vamin
Vuel
+
1
Kg
1 + sTg
Vs
Model Compatibility:
CIM
Model
excST6B
PSLF
Model
esst6b
**. As of rev. 30, not in PSS/E.
Page 86
PSS/E
Model
**
DigSilent
Model
Eurostag
Model
Vr
0
1
vmult
Vb
Π
•
1
1 + sTs
Efd
excST7B - IEEE ST7B Model
Model Name
excST7B
Description
IEEE (2005) ST7B Model
Parameters:
Parameter
Name
Bus number
Unit ID
Tr
Kpa
Kia
Tia
Tb
Tc
Tf
Tg
Kl
Kh
Vrmax
Vrmin
Vmax
Vmin
UELin
sec.
p.u.
p.u.
sec.
sec.
sec.
sec.
sec.
p.u.
p.u.
p.u.
p.u.
p.u.
p.u.
none
0.0
40.
1.
3.0
1.0
1.0
1.0
1.0
1.0
1.0
5.0
-4.5
1.1
0.9
0.0
OELin
none
0.0
Ts
sec.
0.0
Units
Typical
Value
Description
Terminal bus number in power flow case
Generator ID in power flow case
Filter time constant
Regulator proportional gain (> 0.)
Feedback gain (>= 0.)
Feedback time constant (>= 0.)
Lead-lag denominator time constant (>= 0.)
Lead-lag numerator time constant (>= 0.)
Input lead-lag denominator time constant (>= 0.)
Input lead-lag numerator time constant (>= 0.)
Low-value gate feedback gain (>= 0.)
High-value gate feedback gain (>= 0.)
Maximum field voltage output (> 0.)
Minimum field voltage output (< 0.)
Maximum voltage reference signal (> 0.)
Minimum voltage reference signal (> 0.)
UEL input selector: 1 – add to Vref, 2 – input HV gate,
3 – output HV gate, 0 – no UEL input
OEL input selector: 1 – add to Vref, 2 – input LV gate,
2 – output LV gate, 0 – no OEL input
Rectifier firing time constant (>= 0.) (not in IEEE model)
Notes:
a) For modeling static systems such as Alstom Eurorec, Microrec K4.1 and ALSPA P320.
b) Kpa must not be zero. Any of the time constants may be zero. If any time constant is zero, the
respective block is bypassed.
c) If Ts is zero, its block is replaced by a one time step delay.
Block Diagram:
Page 87
Voel
1
Vref
+
2
Vm a x
+
LV
Gate
Σ
+
1
HV
Gate
V m in
Σ
+
Vs
+
Vuel 2
Voel2
Vuel
3
Vc
1
1 + sTr
1 + sTg
1 + sTf
+
Σ
−
HV
Gate
Kpa
Vt * V r m in
+
LV
Gate
Σ
−
Σ
−
1 + sTc
1 + sTb
+
Σ
+
Vr
LV
Gate
V t * Vr m a x
HV
Gate
•
Vt * Vr m in
V t * Vr m a x
+
Kl
•
Kia
1 + sTia
Kh
Model Compatibility:
CIM
Model
excST7B
PSLF
Model
esst7b
**. As of rev. 30, not in PSS/E.
Page 88
PSS/E
Model
**
DigSilent
Model
Eurostag
Model
Ef d
1
1 + sTs
Other Excitation System Models To Be Added
CIM
Model
PSLF
Model
exac1a
exdc4
exbbc
exeli
exeli2
expic1
rexs
scrx
sexs
Page 89
PSS/E
Model
EXAC1A
IEEET4
IEEEX4
IEET5A
BBSEX1
EXELI
CELIN
EXPIC1
REXSYS
SCRX
SEXS
DigSilent
Model
vco_EXAC1A
vco_IEEET4
vco_IEEEX4
vco_IEET5A
vco_BBSEX1
vco_EXELI
vco_CELIN
vco_EXPIC1
vco_REXSYS
vco_SCRX
vco_SEXS
Eurostag
Model
Power System Stabilizer (PSS) Models
The PSS model provides an input (Vs) to the excitation system model to improve damping of
system oscillations. A variety of input signals may be used depending on the particular design.
Model Interconnections
Standard interconnection of PSS models with other models are shown in Figure D-1 and listed in
Table D-1.
Network
frequency
speed
Pelec
Generator
Power System Stabilizer
(PSS)
Vs
Excitation
System
Pmech
Eterm
Figure D-1 PSS Model Standard Interconnections
Table D-1 PSS Model Standard Interconnections
Inputs:
Name
speed
frequency
Pelec
Pmech
Eterm
Units
p.u.
p.u.
p.u.
p.u.
p.u.
Description
Generator speed
Terminal voltage frequency (note b)
Generator electrical power
Generator mechanical power
Generator terminal voltage
Outputs:
Name
Vs
Units
p.u.
Description
PSS signal to excitation system
Initialization Inputs:
Name
Units
speed
p.u.
frequency
p.u.
Pelec
p.u.
Pmech
p.u.
Eterm
p.u.
Page 90
Description
Generator speed
Terminal voltage frequency
Generator electrical power
Generator mechanical power
Generator terminal voltage
Source
Generator
Network
Generator
Generator
Generator
Source
Generator
Network
Generator
Generator
Generator
Vs
p.u.
PSS signal to excitation system (note a)
Exc. System
Notes:
a) Vs is always initialized to zero by the excitation system model.
b) If bus voltage frequency is not available from network, the model can calculate it as derivative
of the bus voltage angle.
Page 91
pssIEEE2B - IEEE PSS2B Power System Stabilizer Model
Model Name
pssIEEE2B
Description
IEEE (2005) PSS2B Model
Parameters:
Parameter
Name
Bus number
Unit ID
J1
K1
J2
K2
Vsi1max
Vsi1min
Tw1
Tw2
Vsi2max
Vsi2min
Tw3
Tw4
T1
T2
T3
T4
T6
T7
T8
T9
T10
T11
Ks1
Ks2
Ks3
n
m
Vstmax
Vstmin
a
Ta
Tb
Notes:
Page 92
Units
none
none
none
none
p.u.
p.u.
sec.
sec.
p.u.
p.u.
sec.
sec.
sec.
sec.
sec.
sec.
sec.
sec.
sec.
sec.
sec.
sec.
p.u.
p.u.
p.u.
none
none
p.u.
p.u.
none
sec.
sec.
Typical
Value
Description
Terminal bus number in power flow case
Generator ID in power flow case
Input signal #1 code
Input signal #1 remote bus number
Input signal #2 code
Input signal #2 remote bus number
Stabilizer output max limit
Stabilizer output min limit
First washout on signal #1
Second washout on signal #1.
Stabilizer output max limit
Stabilizer output min limit.
First washout on signal #2.
Second washout on signal #2.
Lead/lag time constant
Lead/lag time constant
Lead/lag time constant
Lead/lag time constant
Time constant on signal #1
Time constant on signal #2.
Lead of ramp tracking filter
Lag of ramp tracking filter
Lead/lag time constant
Lead/lag time constant.
Stabilizer gain
Gain on signal #2
Gain on signal #2 input before ramp-tracking filter
Order of ramp tracking filter
Denominator order of ramp tracking filter
Stabilizer output max limit
Stabilizer output min limit
Numerator constant
Lead constant
Lag time constant
a) TW1 and TW3 must be greater than zero.
b) Setting TW2 or TW4 to zero will bypass the corresponding washout function.
c) T1, T2, T3, T4, T6, T7, T8, and T9 may be zero.
d) Set T9 = 0 or n = 0 to get a null effect from the ramp tracking filter.
e) The product of n*m cannot be greater than 10.
f) The input signal code, J, and the remote bus number, K, specify the input signal used by the
stabilizer. If K is zero, the signal is taken from the shaft or terminals of the generator on
which the stabilizer is located. If K is non-zero, the signal is taken from bus number K ( for
J = 1, 2, 3, 4, or 5 ).
g) The values of the input signal code, J, are as follows:
1
2
3
4
5
6
shaft speed
frequency of bus voltage
generator electrical power
generator accelerating power
amplitude of bus voltage
derivative of bus voltage amplitude
.
Block Diagram:
Vsi1max
Input 1
sT w1
1+sTw1
sTw2
1+sTw2
1
1+sT 6
Vsi1min
Σ
Ks3
 1+ sT 
8


m
 (1+ sT 9 ) 
n
Σ
Ks1
1+sT1
1+sT2
Ks4
Vstmax
Vsi2max
Input 2
sT w3
1+sTw3
sTw4
1+sTw4
1+sT3
1+sT4
1
1+sT 7
1+sT10
1+sT11
Vstmin
Vsi2min
Model Compatibility:
CIM
Model
pssIEEE2B
Page 93
Vs
a+sTa
1+sTb
PSLF
Model
pss2b
pss2a
PSS/E
Model
DigSilent
Model
PSS2A
pss_PSS2A
Eurostag
Model
Other PSS Models To Be Added
CIM
Model
PSLF
Model
pss1a
pss3b
pss4b
wsccst
psssb
psssh
expic1
ieeest
Page 94
PSS/E
Model
PSS1A
PSS3B
PSS4B
ST2CUT
DigSilent
Model
pss_PSS1A
pss_ST2CUT
EXPIC1
PTIST1
PTIST3
IEEEST
vco_PTIST1
vco_PTIST3
vco_IEEEST
Eurostag
Model
Turbine-Governor Models
The turbine-governor model determines the mechanical power (Pm) to the generator model.
Model Interconnections
Standard interconnection of turbine-governor models with other models are shown in Figure 5-1
and listed in Table 5-1.
speed
Pref
AGC
Pmech
Turbine-Governor
Generator
Figure 5-1 Turbine-Goveror Model Standard Interconnections
Table 5-1 Turbine-Governor Model Standard Interconnections
Inputs:
Name
speed
Pref
Units
p.u.
p.u.
Outputs:
Name
Pmech
Units
p.u.
Description
Generator speed
Load reference
Source
Generator
See note a
Description
Generator mechanical power
Initialization Inputs:
Name
Units
speed
p.u.
Pmech
p.u.
Description
Generator speed (= 1.)
Generator mechanical power
Source
Generator
Generator
Initialization Outputs:
Name
Units
Pref
p.u.
Description
Load reference
Source
See note a
Page 95
Notes:
a) Pref is usually held constant for stability analysis, but may be deteremined by a user-written
model or, for long-term dynamics, an area-wide automatic generation control (AGC) model.
Page 96
govHydro – Hydro Turbine-Governor Model
Model Name
govHydro
Description
Simple hydro turbine-governor model
Parameters:
Parameter
Name
Bus number
Unit ID
MWcap
Rperm
rtemp
Tr
Tf
Tg
Velm
Gmax
Gmin
Tw
At
Dturb
qnl
Units
Typical
Value
MW
p.u.
p.u.
sec.
sec.
p.u.
p.u./sec.
p.u.
p.u.
sec.
p.u.
p.u.
p.u.
Description
Terminal bus number in power flow case
Generator ID in power flow case
Turbine MW capability (> 0.)
Permanent droop (R) (> 0.)
Temporary droop (r) (> R)
Washout time constant (> 0.)
Filter time constant (> 0.)
Gate servo time constant. (> 0.)
Maximum gate velocity. (> 0.)
Maximum gate opening (> 0.)
Minimum gate opening (>= 0.)
Water inertia time constant (> 0.)
Turbine gain. (> 0.)
Turbine damping factor (>= 0.)
No-load flow at nominal head (>= 0.)
Notes:
a) Per unit parameters are on base of turbine MW capability.
"MWcap", the generator MVA base is used.
If no value is given for
b) The gates travel over a range of 1.0 per unit from fully closed to fully opened. The gate
position is normally greater than zero at zero power and normally less than 1.0 when power
is 1.0 p.u. Gmax and Gmin are operating limits.
c) Tr, Tf, Tg, Tw must be greater than zero.
d) Dturb has the dimensions ∆P(pu of mwcap) /∆speed(pu).
Block Diagram:
Model Compatibility:
CIM
Model
Page 97
PSLF
Model
PSS/E
Model
DigSilent
Model
Eurostag
Model
govHydro
hygov
HYGOV
Block Diagram:
Pref
1.
Gmax
ω
∆ω
Σ
1
1 + sTf
Σ
(speed)
1 + sTr
•
rsTr
1
1+ sTg
•
Gmin
gv
∆ω
rate limit = Velm
R
•
Π
Dturb
gv
(gate
position)
d
H
n/d
•
Π
•
Σ
q
•
Σ
n
hdam
Page 98
1
s Tw
qnl
Π
At
Σ
Pm
Other Turbine-Governor Models To Be Added
CIM
Model
PSLF
Model
ggov1
ggov2
ieeeg1
ieeeg3
hyg3
hygov4
hygovr
g2wscc
gast
gpwscc
lfb1
pidgov
tgov1
tgov3
crcmgv
Page 99
PSS/E
Model
GGOV1
GGOV2
WSIEG1
IEEEG2
IEEEG3
WSHYGP
WSHYDD
GAST
GASTWD
MELGAS
WSHYGP
LCFB1
PIDGOV
TGOV1
TGOV2
TGOV3
CRCMGV
IEESGO
WPIDHY
WEHGOV
RAVGOV
DUMGOV
RAVGOV
DigSilent
Model
GGOV1
WSIEG1
IEEEG3
WSHYGP
WSHYDD
GAST
WSHYGP
PIDGOV
TGOV1
TGOV2
TGOV3
CRCMGV
IEESGO
WPIDHY
Eurostag
Model
Aggregate Load Models
The load models in this section are used to represent all or part of the real and reactive load from a
load in the static (power flow) data. This load is usually the aggregation of many individual load
devices. The load models are approximate representation of the aggregate response of the load
devices to system disturbances. Models of loads for dynamic analysis may themselves be either
static or dynamic. A static load model represents the sensitivity of the real and reactive power
consumed by the load to the amplitude and frequency of the bus voltage. A dynamic load model
can used to represent the aggregate response of the motor components of the load. Several
standard models for agregate load are discussed in this section.
Large industrial motors or groups of similar motors may be represented by individual motor models
(synchronous or asynchronous) which are usually represented as generators with negative Pgen in
the static (power flow) data. These models are discussed in earlier sections
Model Interconnections
Standard interconnection of load models with other models are shown in the following figure and
table:
Vbus, fbus
Pload
Load Model
Network
Qload
Load Model Standard Interconnections
Load Model Standard Interconnections
Inputs:
Name
Vbus
fbus
Units
p.u.
p.u.
Outputs:
Name
Pload
Units
p.u.
Page 100
Description
Terminal bus voltage magnitude
Terminal voltage frequency
Description
Load real power
Source
Network
Network
Qload
p.u.
Initialization Inputs:
Name
Units
Pload
p.u.
Qload
p.u.
Vbus
p.u.
Load reactive power
Description
Load real power
Load reactive power
Terminal bus voltage magnitude
Source
Network
Notes:
1. The application program converts the P and Q of the load into a current injection at the bus.
Page 101
loadStatic - Static Load Model
Model Name
loadStatic
Description
General Static Load Model
Parameters:
Parameter
Name
Model Type
Scope Type
Scope Value
Load ID
Kp1
Kp2
Kp3
Kp4
Ep1
Ep2
Ep3
Kpf
Kq1
Kq2
Kq3
Kq4
Eq1
Eq2
Eq3
Kqf
Units
Typical
Value
Description
Exponential, ZIP1, ZIP2
Bus, owner, zone, area, system
Bus number, area number, zone number
Load ID for individual bus load
Notes:
Equations:
Several variations of the static load model are used in various programs. The model type is used
to specify these variations.
Model type –Exponential
Page 102
Ep1
Ep2
Ep3 

 V 
 V 
 V 
 1. + K pf ∆f



P = P0 K p1
+ K p2 
+ K p3 
V0 
V0 
V0 







Eq
1
Eq
2
Eq
3


 V 
 V 
 V 
 1. + K qf ∆f



Q = P0 K q1
+ K q2 
+ K q3 
V
V
V


0
0
0








(
)
(
)
Model type – ZIP1
2
1

 V 
 V 
 V 






P = P0 K p1
 + K p2  V  + K p3  V  1. + K pf ∆f
V

 0
 0 
 0

2
1

 V 
 V 
 V 

 + K q2 
 + K q3 
 1. + K qf ∆f
Q = P0 K q1
V
V
V

 0
 0
 0 

(
)
(
)
Model type – ZIP2
2
1

 V 
 V 
 V 






P = P0 K p1
 + K p2  V  + K p3  V  + K p 4 1. + K pf ∆f
V

 0
 0 
 0

2
1

 V 
 V 
 V 

 + K q2 
 + K q3 
 + K q4 1. + K qf ∆f
Q = P0 K q1
V
V
V

 0
 0
 0 

(
)
(
)
Model Compatibility:
CIM
Model Type
General
Exponential
PSLF
Model
NONE
ZIP1
blwscc
ZIP2
zlwscc
alwscc
wlwscc
blwscc
zlwscc
alwscc
wlwscc
Page 103
PSS/E
Model
IEELBL
IEELOW
IEELZN
IEELAR
IEELAL
IEELBL
IEELOW
IEELZN
IEELAR
IEELAL
LDFRBL
LDFROW
LDFRZN
LDFRAR
LDFRAL
DigSilent
Model
Eurostag
Model
loadMotor - Aggregate Induction Motor Load
Model Name
loadMotor
Description
Aggregate Induction Motor Load
Parameters:
Parameter
Name
Bus number
Unit ID
Pfrac
none
0.3
Lfac
Ls
Lp
Lpp
Ra
Tpo
Tppo
H
D
Vt
Tv
Tbkr
none
p.u.
p.u.
p.u.
p.u.
sec.
sec.
Sec.
p.u.
p.u.
sec.
sec.
0.8
3.2
0.15
0.15
0.0
1.0
0.02
0.4
2.0
0.7
0.1
0.08
Units
Typical
Value
Description
Terminal bus number in power flow case
Generator ID in power flow case
Fraction of constant-power load to be represented
by this motor model (between 1.0 and 0.0)
Loading factor – ratio of initial P to motor MVA base
Synchronous reactance
Transient reactance
Sub-transient reactance, p.u.
Stator resistance, p.u.
Transient rotor time constant
Sub-transient rotor time constant, sec.
Inertia constant, sec.
Damping factor, p.u.
Voltage threshold for tripping (default = 0), p.u.
Voltage trip pickup time (default = 999), sec.
Circuit breaker operating time (default = 999), sec.
Notes:
a) This model is used to represent a fraction of an ordinary load as "induction motor load". It
allows load that is treated as ordinary constant power in power flow analysis to be represented
by an induction motor in dynamic simulation. Either a “one-cage” or “two-cage” model of the
induction machine can be modeled. If Lpp = 0. or Lpp = Lp, or Tppo = 0., only one cage is
represented. Magnetic saturation is not modeled. This model is intended for representation of
aggregations of many motors dispersed through a load represented at a high voltage bus but
where there is no information on the characteristics of individual motors.
b) This model treats a fraction of the constant power part of a load as a motor. During
initialization, the initial power drawn by the motor is set equal to Pfrac times the constant P part
of the static load. The remainder of the load is left as static load.
The reactive power demand of the motor is calculated during initialization as a function of
voltage at the load bus. This reactive power demand may be less than or greater than the
constant Q component of the load. If the motor's reactive demand is greater than the constant Q
component of the load, the model inserts a shunt capacitor at the terminal of the motor to bring
its reactive demand down to equal the constant Q reactive load.
Page 104
.
c) If a motor model and a static load model are both present for a load, the motor Pfrac is
assumed to be subtracted from the power flow constant P load before the static load model is
applied. The remainder of the load, if any, is then represented by the static load model.
d) The rotor time constant Tpo and inertia time constant H must be non-zero.
e) Ls, Lp, Lpp must all be specified.
f) D has the dimensions delta P/ delta speed. The initial value of Pmech or the value coming from
an separate mechanical load model, if used, is multiplied by speed raised to the power D to
determine the effective mechanical load seen by the motor.
g) The parameters Vt and Tv define under-voltage tripping logic. A timer is started if the terminal
voltage falls below Vt per unit and continues to run until voltage rises above Vt. If voltage has
not risen above Vt when the timer reaches Tv the motor is tripped immediately.
h) Per unit parameters are on the motor MVA base. The MVA base is calculated during
initialization as the initial motor P in MW divided by the loading factor (Lfac) parameter
Block Diagram:
Page 105
1. +
Te
Pmech
Σ
d
n
n/d
_
Tm +
_
Σ
ω
+
∆ω
1
2Hs
Σ
speed
slip
D
Σ
1
1
Tpo
s
E'q
Σ
Σ
1
Tppo
ωo SLIP Tpo
Σ
1
s
E"q
d-AXIS
ωo SLIP
Lp - Lpp
id
Σ
Ls - Lp
ωo SLIP
ωo SLIP Tpo
Σ
1
1
Tpo
s
E'd
Σ
Σ
1
Tppo
Σ
1
s
E"d
q-AXIS
Lp - Lpp
Σ
iq
Ls - Lp
Model Compatibility:
CIM
Model
loadMotor
PSLF
Model
motorw
PSS/E
Model
CIM5xx,
CIMWxx
DigSilent
Model
ElmAsm
Eurostag
Model
Notes:
1. PSS/E has several versions (xx) of the models for application to load at an individual bus (BL),
all loads with same owner (OW), all loads in a zone (ZN), all loads in an area (AR), or all loads
in the system (AL). The CIMWxx models include a polynomial mechanical load model [Tl =
To(Aw^2 + Bw + Co + Dw^E)] which should be represented by a separate mechanical load
Page 106
Mechanical Load Models
A mechanical load model is used to represent the variation in a motor’s shaft torque or power as a
function of shaft speed.
Model Interconnections
Standard interconnection of mechanical load models with other models are shown in the following
figure and table:
speed
Pmech
Mechanical Load
Synchronous
or
Asynchronous
Motor
Mechanical Load Model Standard Interconnections
Mechanical Load Model Standard Interconnections
Inputs:
Name
speed
Units
p.u.
Motor speed
Outputs:
Name
Pmech
Units
p.u.
Description
Motor shaft mechanical power
Initialization Inputs:
Name
Units
Pmech
p.u.
speed
p.u.
Page 107
Description
Description
Motor shaft mechanical power
Motor speed
Source
Motor
Source
Motor
Motor
mechload1 - Mechanical Load Model 1
Model Name
mechload1
Description
Mechanical Load Model 1
Parameters:
Parameter
Name
Bus Number
ID
a
b
d
e
Units
Typical
Value
Description
Motor terminal bus number
Generator or Load ID
Speed squared coefficient
Speed coefficient
Speed to the exponent coefficient
Exponent
Notes:
Equations:
(
Tmech = T0 aω2 + b ω + c + dωe
Pmech =
)
Tmech
ωDM−1
where :
c = 1.0 − a − b − d
ωoDM−1
To = initial torque =
Tmech(ωo )
ωo = initial motor speed
Model Compatibility:
CIM
Model Type
mechload1
Page 108
PSLF
Model
apfl
spfl
PSS/E
Model
DigSilent
Model
mdm1
mdm3
mdm5
Eurostag
Model