# Pref Controller Model: WTGTRQ_A and WTTQA1

In PTI: **WTTQA1** is the same as **WTGTRQ_A** model.

AutoCorrection Properties

Following checks and corrections are applied during Validation and AutoCorrection.

- If 0.0 < Tp < 0.125*Mult*TimeStep then Tp = 0.0

ElseIf 0.125*Mult*TimeStep < Tp < 0.25*Mult*TimeStep then Tp = 0.25*Mult*TimeStep - If 0.0 < Twref < 0.125*Mult*TimeStep then Twref = 0.0

ElseIf 0.125*Mult*TimeStep < Twref < 0.25*Mult*TimeStep then Twref = 0.25*Mult*TimeStep

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 for WTGTRQ_A:**

Flag | 0=Torque Control; 1=Speed control; 2=Alternative with Pref0 feeding to Temax value |

Kip | Integral Gain |

Kpp | Proportional Gain |

Tp | Power measurement lag time constant |

Twref | Speed measurement time constant |

Temax | Maximum torque |

Temin | Minimum torque |

P1 | Power Point 1 for mapping of Pelec to speed function |

Speed1 | Speed Point 1 for mapping of Pelec to speed function |

P2 | Power Point 2 for mapping of Pelec to speed function |

Speed2 | Speed Point 2 for mapping of Pelec to speed function |

P3 | Power Point 3 for mapping of Pelec to speed function |

Speed3 | Speed Point 3 for mapping of Pelec to speed function |

P4 | Power Point 4 for mapping of Pelec to speed function |

Speed4 | Speed Point 4 for mapping of Pelec to speed function |

MVABase | MVA Base for model |

**Parameters for WTTQA1:**

Flag | 0=Torque Control; 1=Speed control; 2=Alternative with Pref0 feeding to Temax value |

Kpp | Proportional Gain |

Kip | Integral Gain |

Tp | Power measurement lag time constant |

Twref | Speed measurement time constant |

Temax | Maximum torque |

Temin | Minimum torque |

P1 | Power Point 1 for mapping of Pelec to speed function |

Speed1 | Speed Point 1 for mapping of Pelec to speed function |

P2 | Power Point 2 for mapping of Pelec to speed function |

Speed2 | Speed Point 2 for mapping of Pelec to speed function |

P3 | Power Point 3 for mapping of Pelec to speed function |

Speed3 | Speed Point 3 for mapping of Pelec to speed function |

P4 | Power Point 4 for mapping of Pelec to speed function |

Speed4 | Speed Point 4 for mapping of Pelec to speed function |

MVABase | MVA Base for model |