The properties, in numerical order, are:


Property

Description

bus1

Name of bus to which the generator is connected. Include node definitions if the terminal conductors are connected unusually. 3-phase Wye-connected generators have 4 conductors; Delta-connected have 3. Wye-connected generators, in general, have one more conductor than phases. 1-phase Delta has 2 conductors; 2-phase has 3. The remaining Delta, or line-line, connections have the same number of conductors as phases.

Phases

No. of phases this generator.

Kv

Base voltage for generator. For 2- or 3-phase generators, specified in phase-to-phase kV. For all other generators, the actual kV across the generator branch. If wye (star) connected, specify the phase-to-neutral (L-N) kV. If delta or phase-to-phase connected, specify the phase-to-phase (L-L) kV.

Kw

nominal kW for generator. Total of all phases.

Pf

nominal Power Factor for generator. Negative PF is leading (absorbing vars). Specify either PF or kvar (see below). If both are specified, the last one specified takes precedence.

Model

Integer defining how the generator will vary with voltage. Presently defined models are:

1: Generator injects a constant kW at specified power factor.

2: Generator is modeled as a constant admittance.
3: Const kW, constant kV. Somewhat like a conventional transmission power flow P-V generator.

4: Const kW, Fixed Q (Q never varies)

5: Const kW, Fixed Q(as a constant reactance)

6: Compute load injection from User-written Model.(see usage of Xd, Xdp)

7: Constant kW, kvar, but current is limited when voltage is below Vminpu

Yearly

Name of Yearly load shape.

Daily

Name of Daily load shape.

Duty

name of Duty cycle load shape. Defaults to Daily load shape if not defined.

Dispvalue

Dispatch value. If = 0.0 then Generator follows dispatch curves. If > 0 then Generator is ON only when the global load multiplier exceeds this value. Then the generatorfollows dispatch curves (see also Status)

Conn

{wye | y | LN} for Wye (Line-Neutral) connection; {delta | LL} for Delta (Line-Line) connection. Default = wye.

Kvar

Base kvar. If this is specified, will supercede PF. (see PF)

Rneut

Neutral resistance ohms. If entered as negative, non-zero number, neutral is assumed open, or ungrounded. Ignored for delta or line-line connected generators. Default is 0.

Xneut

Neutral reactance, ohms. Ignored for delta or line-line connected generators. Assumed to be in series with Rneut value.

Status

{fixed | variable}. If Fixed, then dispatch multipliers do not apply. The generator is always at full power when it is ON. Default is Variable (follows curves).

Class

Integer number segregating the generator according to a particular user-defined class. Can be any number.

Maxkvar

Maximum kvar limit for Model = 3. Defaults to twice the specified load kvar. Always reset this if you change PF or kvar properties.

Minkvar

Minimum kvar limit for Model = 3. Enter a negative number if generator can absorb vars. Defaults to negative of Maxkvar. Always reset this if you change PF or kvar properties.

Pvfactor

Convergence deceleration factor for P-V generator model (Model=3). Default is 0.1. If the circuit converges easily, you may want to use a higher number such as 1.0. Use a lower number if solution diverges. Use Debugtrace=yes to create a file that will trace the convergence of a generator model.

Debugtrace

{Yes | No } Default is no. Turn this on to capture the progress of the generator model for each iteration. Creates a separate file for each generator named "GEN_name.CSV".

Vminpu

Default = 0.95. Minimum per unit voltage for which the Model is assumed to apply. Below this value, the generator model reverts to a constant impedance model. For Model 7, this is used to determine the upper current limit. For example, if Vminpu is 0.90 then the current limit is (1/0.90) = 111%.

Vmaxpu

Default = 1.05. Maximum per unit voltage for which the Model is assumed to apply.
Above this value, the generator model reverts to a constant impedance model.

ForceON

{Yes | No} Forces generator ON despite requirements of other dispatch modes. Stays ON until this property is set to NO, or an internal algorithm cancels the forced ON state.

kVA

kVA rating of electrical machine. Defaults to 1.2* kW if not specified. Applied to machine or inverter definition for Dynamics mode solutions.

MVA

MVA rating of electrical machine. Alternative to using kVA=.

Xd

Per unit synchronous reactance of machine. Presently used only for Thevenin impedance for power flow calcs of user models (model=6). Typically use a value from 0.4 to 1.0. Default is 1.0

Xdp

Per unit transient reactance of the machine. Used for Dynamics mode and Fault studies. Default is 0.27.For user models, this value is used for the Thevenin/Norton impedance for Dynamics Mode.

Xdpp

Per unit subtransient reactance of the machine. Used for Harmonics. Default is 0.20.

H

Per unit mass constant of the machine. MW-sec/MVA. Default is 1.0.

D

Damping constant. Usual range is 0 to 4. Default is 1.0. Adjust to get damping

UserModel

Name of DLL containing user-written model, which computes the terminal currents for Dynamics studies, overriding the default model. Set to "none" to negate previous setting.

UserData

String (in quotes or parentheses) that gets passed to user-written model for defining the data required for that model.

ShaftModel

Name of user-written DLL containing a Shaft model, which models the prime mover and determines the power on the shaft for Dynamics studies. Models additional mass elements other than the single-mass model in the DSS default model. Set to "none" to negate previous setting.

ShaftData

String (in quotes or parentheses) that gets passed to user-written shaft dynamic model for defining the data for that model.

DutyStart

Starting time offset [hours] into the duty cycle shape for this generator, defaults to 0.

Balanced

{Yes | No*} Default is No. For Model=7, force balanced current only for 3-phase generators. Force zero- and negative-sequence to zero.

XRdp

Default is 20. X/R ratio for Xdp property for FaultStudy and Dynamic modes. Required to match published textbook fault study cases that have generators with both R and X specified.



Inherited Properties


spectrum

Name of harmonic voltage or current spectrum for this generator. Voltage behind Xd" for machine - default. Current injection for inverter. Default value is "default", which is defined when the DSS starts.

Basefreq

Base frequency for which this generator is defined. Default is 60.0

Like

Name of another Generator object on which to base this one