# Plant Controller Model: REPC_A, REPCA1 and REPCTA1

In PTI:

- When used for modeling of **Type 3** wind machine, the model is named **REPCTA1**, and the is used along with REGCA1, REECA1, WTDTA1, WTPTA1, WTARA1 and WTTQA1

-When used for modeling of **Type 4** machines, the model is named **REPCA1**, and is uses along with are REGCA1, REECA1 and WTDTA1.

Following checks and corrections are applied during Validation and AutoCorrection.

- If 0 < Ddn < Mult*TimeStep then Ddn = Mult*TimeStep
- If 0 < Dup < Mult*TimeStep then Dup = Mult*TimeStep
- If 0.0 < Tflr < 0.5*Mult*TimeStep then Tflr = 0, ElseIf 0.5*Mult*TimeStep < Tflr < Mult*TimeStep then Tflr = Mult*TimeStep
- If 0.0 < Tp < 0.5*Mult*TimeStep then Tp = 0, ElseIf 0.5*Mult*TimeStep < Tp < Mult*TimeStep then Tp = Mult*TimeStep
- If 0.0 < Tlag < 0.5*Mult*TimeStep then Tlag = 0, ElseIf 0.5*Mult*TimeStep < Tlag < Mult*TimeStep then Tlag = Mult*TimeStep
- If Femax < Femin then swap the values. If Femax < 0 then Femax change sign to positive. If Femin > 0 then change sign to negative.
- If Emax < Emin then swap the values. If Emax < 0 then Emax change sign to positive. If Emin > 0 then change sign to negative.
- Dbd, dbd1 and dbd2:
- If Branch is not specified: If RefFlag = 1, and Vcomp = 1 and FreqFlag = 0 do nothing else Must specify a branch on which P, Q, and I measurements are taken.
- If Branch is specified: Measurement Bus must be one of the terminals of the Measurement Branch.

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

Following treatment is handled during the transient numerical simulation

- If Reactive PI > Qmax, then Qmax = Reactive PI or if Reactive Pi < Qmin, then Qmin = Reactive Pi
- If PI Power limits > Pmax, then Pmax = PI Power limits or if PI Power limits < Pmin, then Pmin = PI Power limits

Model Equations and/or Block Diagrams

**Parameters for REPC_A:**

RefFlag | Reference Flag: 1 = voltage control; 0 = reactive power control |

VcompFlag | Selection of droop (0) or line drop compensation (1) |

Freqflag | Flag to turn on (1) or off (0) the active power control loop within the plant controller |

Tfltr | Voltage or reactive power measurement filter time constant |

Kp | Proportional gain |

Ki | Integral gain |

Tft | Lead time constant |

Tfv | Lag time constant |

Vfrz | Voltage below which plant control integrator state is frozen |

Rc | Line drop compensation resistance |

Xc | Current compensation constant (to emulate droop or line drop compensation) |

Kc | Gain on reactive current compensation |

emax | Maximum error limit |

emin | Minimum error limit |

dbd | Deadband in control |

Qmax | Maximum Q control output |

Qmin | Minimum Q control output |

Kpg | Proportional gain for power control |

Kig | Integral gain for power control |

Tp | Lag time constant on Pgen measurement |

fdbd1 | Deadband downside |

fdbd2 | Deadband upside |

femax | Maximum error limit |

femin | Minimum error limit |

Pmax | Maximum Power |

Pmin | Minimum Power |

Tlag | Lag time constant on Pref feedback |

Ddn | Downside droop |

Dup | Upside droop |

MVABase | Model MVA base |

PUflag | PUFlag: 0 means that inputs Pbranch, Qbranch and Ibranch are on the system MVABase, otherwise they are the model MVABase |

**Parameters for REPCA1:**

RefFlag | Reference Flag: 1 = voltage control; 0 = reactive power control |

VcompFlag | Selection of droop (0) or line drop compensation (1) |

Freqflag | Flag to turn on (1) or off (0) the active power control loop within the plant controller |

Tfltr | Voltage or reactive power measurement filter time constant |

Kp | Proportional gain |

Ki | Integral gain |

Tft | Lead time constant |

Tfv | Lag time constant |

Vfrz | Voltage below which plant control integrator state is frozen |

Rc | Line drop compensation resistance |

Xc | Current compensation constant (to emulate droop or line drop compensation) |

Kc | Gain on reactive current compensation |

emax | Maximum error limit |

emin | Minimum error limit |

dbdlow | Deadband low in control |

Qmax | Maximum Q control output |

Qmin | Minimum Q control output |

Kpg | Proportional gain for power control |

Kig | Integral gain for power control |

Tp | Lag time constant on Pgen measurement |

fdbd1 | Deadband downside |

fdbd2 | Deadband upside |

femax | Maximum error limit |

femin | Minimum error limit |

Pmax | Maximum Power |

Pmin | Minimum Power |

Tlag | Lag time constant on Pref feedback |

Ddn | Downside droop |

Dup | Upside droop |

dbdupper | Deadband upper in control |

PUflag | PUFlag: 0 means that inputs Pbranch, Qbranch and Ibranch are on the system MVABase, otherwise they are the model MVABase |

**Parameters for REPCTA1:**

RefFlag | Reference Flag: 1 = voltage control; 0 = reactive power control |

VcompFlag | Selection of droop (0) or line drop compensation (1) |

Freqflag | Flag to turn on (1) or off (0) the active power control loop within the plant controller |

Tfltr | Voltage or reactive power measurement filter time constant |

Kp | Proportional gain |

Ki | Integral gain |

Tft | Lead time constant |

Tfv | Lag time constant |

Vfrz | Voltage below which plant control integrator state is frozen |

Rc | Line drop compensation resistance |

Xc | Current compensation constant (to emulate droop or line drop compensation) |

Kc | Gain on reactive current compensation |

emax | Maximum error limit |

emin | Minimum error limit |

dbdlow | Deadband low in control |

Qmax | Maximum Q control output |

Qmin | Minimum Q control output |

Kpg | Proportional gain for power control |

Kig | Integral gain for power control |

Tp | Lag time constant on Pgen measurement |

fdbd1 | Deadband downside |

fdbd2 | Deadband upside |

femax | Maximum error limit |

femin | Minimum error limit |

Pmax | Maximum Power |

Pmin | Minimum Power |

Tlag | Lag time constant on Pref feedback |

Ddn | Downside droop |

Dup | Upside droop |

dbdupper | Deadband upper in control |

PUflag | PUFlag: 0 means that inputs Pbranch, Qbranch and Ibranch are on the system MVABase, otherwise they are the model MVABase |