# Machine Model: REGFM_A1

AutoCorrection Properties

Following checks and corrections are applied during Validation and AutoCorrection.

- Xe < 0.0001 is not allowed, and a value of 0.0001 will be used if a smaller one is entered.
- For TPf, TQf, TVf time constant, any value less than Mult*TimeStep will be modified. If less than 0.5*Mult*TimeStep will be set to 0.0, otherwise it will be increased to Mult*TimeStep.
- Parameters Emax/Emin, Pmax/Pmin, and Qmax/Qmin will be checked for consistency and flipped if entered backwards.

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:**

TPf | Filter time constant for P measurement (s) |

TQf | Filter time constant for Q measurement (s) |

TVf | Filter time constant for V measurement (s) |

Re | Inverter coupling resistance (pu) |

Xe | Inverter coupling reactance (pu), must be greater than zero |

Imax | Inverter maximum output current (pu), Zero means ignore Imax |

Emax | Upper limit of the output of voltage controller |

Emin | Lower limit of the output of voltage controller |

Pmax | Upper limit of the inverter active power control |

Pmin | Lower limit of the inverter active power control |

Qmax | Upper limit of the inverter reactive power control |

Qmin | Lower limit of the inverter reactive power control |

Mp | P-Freq Droop gain |

Mq | Q-V Droop gain |

Kpv | Proportional gain for voltage controller |

Kiv | Integral gain for voltage controller (>0) |

Kppmax | Proportional gain of the Pmax and Pmin controller |

Kipmax | Integral gain of the Pmax and Pmin controller |

Kpqmax | Proportional gain of the Qmax and Qmin controller |

Kiqmax | Integral gain of the Qmax and Qmin controller |

Vflag | Voltage Control Mode Selection. <>0 to use PI controller; =0 to directly set internal voltage |

QVflag | Input Mode Selection. <>0 to use Voltage as a input; =0 to use Reactive Power Q as an input |