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Squirrel Cage Induction Machine

Description

Input Parameters

Description

The Squirrel Cage Induction Machine can be operated in either 'speed control' or 'torque control' modes. In speed controlmode, the machine rotates at the speed specified at the input W. In torque control mode, the speed is calculated based onthe machine inertia, damping, the input torque and the output torque.

Normally, the machine is started in speed control mode with the W input set to rated per-unit speed (say 0.98) and then

switched over to torque control after the initial transients of the machine die out (i.e. reaches steady-state). This

component may also be used with the Multi-Mass Torsional Shaft Interface.

For more details on basic machine simulation theory, see Introduction to Machines.

Input Parameters

Configuration

More: Data Generation/EntryInterfacing to the Multi-Mass Torsional ShaftTerminal DescriptionsCoherent MachinesMagnetizing (main) Saturation Curve

Leakage Saturation CurveSquirrel-Cage Induction Motor

Motor

NameText

Just an identifier. A name should be entered here to avoid compilation

warnings

Data

Generation/Entry

Drop ListEnter Typical, Explicit or EMTP Type 40 data entry format. SeeData Generation/Entry for more details

Multi-massInterface

Drop ListSelect Enable or Disable. See Interfacing to the Multi-Mass TorsionalShaft for more details

Number ofCoherent

Machines

REAL VariableEnter the number of machines acting coherently. See CoherentMachines for more details

Number ofSub-

Iteration

Steps

INTEGER ConstantEnter a number to specify the number of sub-iterations per main timestep. Increase this number if you have convergence problems. Thedefault value of 1 is normally adequate

Rated RMS

PhaseVoltage

REAL Constant Enter the line-to-neutral, RMS rated voltage of the machine [kV]

Rated RMSPhase

REAL Constant Enter the RMS rated line current of the machine [kA]

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Typical Data Format

Explicit Data Format

EMTP Type 40 Format

Current

BaseAngular

Frequency

REAL Constant Enter the machine base angular frequency [rad/s]

GraphicsDisplay

Drop List Select 3-Phase View or Single Line View

HorsePower

REAL ConstantEnter the machine rated horse power if Data Generation/ Entry is selectedas 'Typical' only (1 HP = 0.746 kW)

MutualSaturation

DropList

Select Enabled or Disabled. See Magnetizing (main) Saturation Curvefor more details

LeakageSaturation

DropList

Select Enabled or Disabled. See Leakage Saturation Curve for moredetails

StatorResistance

REAL Constant Enter the stator winding resistance [pu]

First CageResistance

REAL Constant Enter the 1st rotor cage resistance [pu]

SecondCage

ResistanceREAL Constant Enter the 2nd rotor cage resistance [pu]

StatorUnsaturated

LeakageReactance

REAL Constant Enter the stator leakage reactance [pu]

UnsaturatedMagnetizingReactance

REAL Constant Enter the stator main reactance [pu]

RotorUnsaturated

MutualReactance

REAL Constant Enter the mutual reactance between the two rotor cages [pu]

SecondCage

Unsaturated

Reactance

REAL Constant Enter the second cage leakage reactance [pu]

Polar

Moment of

Inertia(J=2H)

REAL Constant

MechanicalDamping

REAL ConstantEnter the mechanical damping to compensate for friction and windageloss [pu]

Design

RatioREAL Constant

The reactance/resistance values of the two rotor cages are derived

based from this ratio [pu]

Power



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Magnetizing (main) Saturation Curve

Leakage Saturation Curve

Factor atRatedLoad

REAL Constant Enter the power factor at rated load [pu]

Efficiencyat Rated

LoadREAL Constant Enter the efficiency at rated load [pu]

Slip at Full

Load

REAL Constant Enter the slip at full load [pu]

MinimumExtinction

TimeREAL Constant Enter the power factor at rated load [pu]

StartingCurrent at

Full Volts

REAL Constant Enter the starting current at full volts [pu]

Starting

Torque atFull Volt /Full Load

Torque

REAL Constant Enter the starting full load torque [pu]

MaximumTorque /Full Load

Torque

REAL Constant Enter the maximum full load torque [pu]

Number ofPoles

INTEGER Constant Enter the number of stator poles

PolarMoment ofInertia (J)

REAL Constant The units are [kgm2] or [MWs/MVA] depending on Units of the

Inertia below.

Units ofthe Inertia

REAL Constant Select either kgm2

or MWs/MVA

MechanicalDamping

REAL Constant Enter the mechanical damping to compensate for friction and windageloss [pu]

NOTE: These properties are only enabled ifData Generation/Entry is set to Explicit and Mutual Saturation isset to Enabled. See Magnetizing (main) Saturation Curve for more details on setting these properties.

MagnetizingCurrentPoint 1

REAL Constant First current point of the magnetizing curve [pu]

MagnetizingVoltagePoint 1

REAL Constant First voltage point of the magnetizing curve [pu]

(I, V) Point#

REAL Constant Enter the remaining points for magnetizing curve of the machine [pu]

NOTE: These properties are only enabled ifData Generation/Entry is set to Explicit and Leakage Saturation

is set to Enabled. See Leakage Saturation Curve for more details on setting these properties.

ShortCircuit

CurrentREAL Constant First current point of the leakage saturation curve [pu]



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Internal Output Variables

Point 1

ShortCircuit

VoltagePoint 1

REAL Constant First voltage point of the leakage saturation curve [pu]

(I, V)Point #

REAL ConstantEnter the remaining points for leakage saturation curve of the machine[pu]

Name forReal

Power(+=in)

(pu)

REAL Output Enter a name for machine real power [pu]

Name forReactive

Power(+=in)

(pu)

REAL Output Enter a name for machine reactive power [pu]

Name forOutputRotorAngle(rad)

REAL Output Enter a name for rotor angle [rad]

Name forOutput

MechanicalTorque

(pu)

REAL Output Enter a name for mechanical torque [pu]

Name forOutputSpeed

(pu)

REAL Output Enter a name for output speed [pu]

Name forElectrical

Torque(pu)

REAL Output Enter a name for electrical torque [pu]

Name forTorque

Angle(rad)

REAL Output Enter a name for the machine torque angle [rad]

Name forSlip Angle

(rad)REAL Output Enter a name for the machine slip angle [rad]

Name forMutualSaturation

Factor

REAL Output Enter a name for the machine mutual saturation factor

Name forLeakage

Saturation

Factor

REAL Output Enter a name for Leakage Saturation Factor


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