master:multimassdefn parametersPSCAD multimassdefn

Every parameter of the PSCAD multimassdefn (master:multimassdefn): 57 names, with the unit, the default and the meaning PSCAD gives each one. Copy a name into parameters().

What master:multimassdefn is

multimassdefn (Multimass Torsional Model), a component of PSCAD's Master Library, filed under control blocks.

Definition
master:multimassdefn
PSCAD name
multimassdefn
Category
Control blocks
Parameters
57, in 8 groups; 9 carry a unit
Read from
PSCAD 5.0.0, 2026-11-07

Read and write master:multimassdefn in Python

import mhi.pscad

pscad = mhi.pscad.connect()              # the PSCAD that is open; launch() starts one
project = pscad.project("my_case")       # a case loaded in the workspace

for comp in project.find_all("master:multimassdefn"):   # the exact definition, namespace first
    params = comp.parameters()           # every parameter, as PSCAD holds it
    print(str(params["F"]))              # Electrical base frequency, in Hz

comp = project.find_all("master:multimassdefn")[0]
comp.parameters(F="120 [Hz]")            # a value that carries a unit is written with it
  • A parameter is named exactly as in the table, letter case included: parameters() gives every one of them in a dictionary, and a name the component does not have is refused.
  • A value that carries a unit comes back as a number whose unit is only in its text, so read it as text first (str(...)) or the unit is lost. PSCAD keeps a written unit as it is given: "2500 [mohm]" stays in mohm.
  • A Choice is read and written as its symbol (the capitals in "Written as"), not as the words PSCAD shows in the dialog.
  • find_all() takes the exact definition only. A wildcard or a bare name without master: comes back empty; the Builder's px_find walks the pages for those.

The Builder's runtime does the same with the unit handled for you: px_get(comp, "F") and px_set(...), which also records the old value so the case is put back at the end. Getting started shows them.

Configuration

ParameterUnitDefaultDescription
ExcInteger·1Model Exciter Mass (1=Yes, 0=No)Range 0 to 1
FRealHz60.0Electrical base frequencyAt least 0
MVARealMVA892.4Machine 3 phase MVAAt least 0
NInteger·4Number of Turbines (1 to 5)Range 1 to 5
NgataInteger·1Icon input: No. of enable inputsRange 1 to 2
RPMRealrev/min3600.0Machine rated speedAt least 0
UnitsInteger·9Unit System Number (See Help)Range 1 to 10

Inertia Constants

ParameterUnitDefaultDescription
H1Real·0.0929Turbine #1 Inertia ConstantAt least 0
H2Real·0.1556Turbine #2 Inertia ConstantAt least 0Used when (N>=2)
H3Real·0.8587Turbine #3 Inertia ConstantAt least 0Used when (N>=3)
H4Real·0.8842Turbine #4 Inertia ConstantAt least 0Used when (N>=4)
H5Real·0.0Turbine #5 Inertia ConstantAt least 0Used when (N>=5)
HEReal·0.0342Exciter Inertia ConstantAt least 0Used when (Exc)
HGReal·0.8685Generator Inertia ConstantAt least 0

Shaft Spring Constant

ParameterUnitDefaultDescription
K12Real·7277Spring Constant From Turbine #1 to #2At least 0Used when (N>=2)
K23Real·13168Spring Constant From Turbine #2 to #3At least 0Used when (N>=3)
K34Real·19618Spring Constant From Turbine #3 to #4At least 0Used when (N>=4)
K45Real·0.0Spring Constant From Turbine #4 to #5At least 0Used when (N>=5)
KGEReal·1064Spring Const. From Generator to ExciterAt least 0Used when (Exc)
KLGReal·26713Spring Const. From Last Turb. to Gen.At least 0

Mutual Damping

ParameterUnitDefaultDescription
MD12Real·0.0Damping Between Turbine #1 and #2At least 0Used when (N>=2)&&(Units>5)
MD23Real·0.0Damping Between Turbine #2 and #3At least 0Used when (N>=3)&&(Units>5)
MD34Real·0.0Damping Between Turbine #3 and #4At least 0Used when (N>=4)&&(Units>5)
MD45Real·0.0Damping Between Turbine #4 and #5At least 0Used when (N>=5)&&(Units>5)
MDGEReal·0.0Damping Between Generator and ExciterAt least 0Used when (Exc)&&(Units>5)
MDLGReal·0.0Damping Between Last Turbine and Gen.At least 0Used when (Units>5)

Internal Output Variable Names

ParameterUnitDefaultDescription
P1Text··Mech. Pos. of Mass 1 wrt Gen.
P2Text··Mech. Pos. of Mass 2 wrt Gen.
P3Text··Mech. Pos. of Mass 3 wrt Gen.
P4Text··Mech. Pos. of Mass 4 wrt Gen.
P5Text··Mech. Pos. of Mass 5 wrt Gen.
P6Text··Mech. Pos. of Mass 6 wrt Gen.
T12Text··Torque on Shaft from Mass 1 - 2
T23Text··Torque on Shaft from Mass 2 - 3
T34Text··Torque on Shaft from Mass 3 - 4
T45Text··Torque on Shaft from Mass 4 - 5
T56Text··Torque on Shaft from Mass 5 - 6
W1Text··Delta Mech. Speed of Mass 1
W2Text··Delta Mech. Speed of Mass 2
W3Text··Delta Mech. Speed of Mass 3
W4Text··Delta Mech. Speed of Mass 4
W5Text··Delta Mech. Speed of Mass 5
W6Text··Delta Mech. Speed of Mass 6
WbasText··Rated Mech. Speed of the System

Self Damping

ParameterUnitDefaultDescription
SD1Real·0.0Turbine #1 Self DampingAt least 0Used when (Units>5)
SD2Real·0.0Turbine #2 Self DampingAt least 0Used when (N>=2)&&(Units>5)
SD3Real·0.0Turbine #3 Self DampingAt least 0Used when (N>=3)&&(Units>5)
SD4Real·0.0Turbine #4 Self DampingAt least 0Used when (N>=4)&&(Units>5)
SD5Real·0.0Turbine #5 Self DampingAt least 0Used when (N>=5)&&(Units>5)
SDEReal·0.0Exciter Self DampingAt least 0Used when (Exc)&&(Units>5)
SDGReal·0.0Generator Self DampingAt least 0Used when (Units>5)

Turbine Torque Share

ParameterUnitDefaultDescription
TF1Realpu0.30Torque Share for Turbine #1Range 0 to 1Used when (N>1)
TF2Realpu0.26Torque Share for Turbine #2Range 0 to 1Used when (N>=2)
TF3Realpu0.22Torque Share for Turbine #3Range 0 to 1Used when (N>=3)
TF4Realpu0.22Torque Share for Turbine #4Range 0 to 1Used when (N>=4)
TF5Realpu0.0Torque Share for Turbine #5Range 0 to 1Used when (N>=5)

Uniform Modal Damping

ParameterUnitDefaultDescription
sigmaReal1/s0.0Modal Damping for all modesAt least 0Used when (Units<=5)

Related

← master:mmc_MultiDimComparator Multi Dimensional Comparator · master:mrun Multiple Run →