# Machine Model: PVD1

AutoCorrection Properties

Following checks and corrections are applied during Validation and AutoCorrection.

- If 0.0 < Tf < 0.5*Mult*TimeStep then Tf = 0, ElseIf 0.5*Mult*TimeStep < Tf < Mult*TimeStep then Tf = Mult*TimeStep
- If Tg < 4*TimeStep then Tg = 4*TimeStep, and if Tg > 0.2 then Tg = 0.2

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:**

Pqflag | Priority to reactive current (0) or active current (1) |

Xc | Line drop compensation reactance (pu on mbase) |

Qmx | Maximum change in reactive power due to voltage droop response (in pu on mbase) |

Qmn | Minimum change in reactive power due to voltage droop response (in pu on mbase) |

V0 | Lower limit of deadband for voltage droop response (pu) |

V1 | Upper limit of deadband for voltage droop response (pu) |

Dqdv | Voltage droop response characteristic |

fdbd | Overfrequency deadband for governor response (pu deviation) |

Ddn | Down regulation droop gain (pu on mbase) |

Imax | Apparent current limit (pu on mbase) |

Vt0 | Voltage below which all generation is tripped (pu) |

Vt1 | Voltage below which generation starts to trip (pu) |

Vt2 | Voltage above which generation starts to trip (pu) |

Vt3 | Voltage above which all generation is tripped (pu) |

Vrflag | Fraction of generation that can reconnect after low or high voltage tripping. 0.0 means voltage tripping is permanent; 1.0 means all generation can reconnect; Between 0 and 1 for partially self-resetting |

Ft0 | Frequency below which all generation is tripped (pu) |

Ft1 | Frequency below which generation starts to trip (pu) |

Ft2 | Frequency above which generation starts to trip (pu) |

Ft3 | Frequency above which all generation is tripped (pu) |

Frflag | Fraction of generation that can reconnect after low or high frequency tripping. 0.0 means frequency tripping is permanent; 1.0 means all generation can reconnect; Between 0 and 1 for partially self-resetting |

Tg | Inverter current lag time constant (seconds) |

Tf | Frequency measurement lag time constant (seconds) |

Vtmax | Voltage limit for high voltage clamp logic (pu) |

Lvpnt1 | Low voltage active current management breakpoint 1 (pu) |

lvpnt0 | Low voltage active current management breakpoint 0 (pu) |

qmin | High Voltage reactive current management term for PSLF (not used by PowerWorld) |

accel | High Voltage reactive current management term for PSLF (not used by PowerWorld) |