Load Characteristic Model: MOTORX

 

Following checks and corrections are applied during Validation and AutoCorrection.

  • R1: 1) If motor is not Double Cage or Type 1, then if circuit parameters result in a Tp time constant which is too small then set R1 to a multiple of Tp/(Minimum time constant size as a multiple of time step). 2) If motor is Double Cage, then if circuit parameters result in a Tpp time constant which is too small then change the motor to single cage by setting R2 and X2 to zero only if Tpp is less than Half the Minimum time constant size as a multiple of time step, and if not just set R1 to a multiple of Tpp/(Minimum time constant size as a multiple of time step).
  • R2: 1) If motor is Double Cage and Type 1, then if circuit parameters result in a Tpp time constant which is too small then change the motor to single cage by setting R2 and X2 to zero only if Tpp is less than Half the Minimum time constant size as a multiple of time step, and if not just set R2 to a multiple of Tpp/(Minimum time constant size as a multiple of time step).

Mult represents the user-specified value Minimum time constant size as multiple of time step option on the Validation page of the Transient Stability Dialog

TimeStep represents the integration time step being used as described on TimeStep

Model Equations and/or Block Diagrams

Parameters:

MBase MBase: MBase of Load Model
AppliesTo 0 means it applies to all, 1 means it applies to only the constant power part of the load
Pul Pul: Fraction of constant-power load to be represented by this motor model (between 1.0 and 0.0)
Rs Rs: Stator winding resistance, p.u.
Xs Xs: Stator winding reactance, p.u.
Xm Xm: Magnetizing reactance, p.u.
R1 R1: Rotor resistance, p.u.
X1 X1: Rotor leakage reactance, p.u.
R2 R2: Rotor resistance, p.u. (0 for single cage motor)
X2 X2: Rotor leakage reactance, p.u. (0 for single cage motor)
H H: Inertia constant, sec.
D D: Damping factor, p.u.
Vt Vt: Voltage threshold for tripping, p.u.
Tv Tv: Voltage trip pickup time, sec.
Tbkr Tbkr: Circuit breaker operating time, sec.
Acc Acc: Acceleration factor for initialization
ndelt ndelt: Time step subdivision factor.
wdelt wdelt: Speed threshold for subdividing time step, p.u.
pfact pfact: Mbase Multiplier