# Machine Model: REGFM_B1

AutoCorrection Properties

Following checks and corrections are applied during Validation and AutoCorrection.

- 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.

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:**

wFlag | Flag to select which speed deviation to use for Power-Frequency droop. =0 to use Dwm; <>0 to use DwPLL |

VdrpFlag | Flag to select either Current or Reactive Power Droop. If QVFlag=0 then VdrpFlag will be ignored and treated as 0 regardless. =0 for Power; <>0 for Current. |

QVflag | Input Mode Selection determines whether input value is Qref or Vref. =0 to use Reactive Power Q as an input; <>0 to use Voltage as an input |

PQflag | PQ priority flag specifies a priority used for the steady state current limitation. =0 to use Q priority; <>0 to use P priority |

FFlag | Flag determine if the Power-Frequency droop is enabled. =0 to disable Power-Frequency Droop; <> 0 to enable Power-Frequency Droop |

ESFlag | Flag determines if the model supports energy storage (negative real power or current). =0 to prevent negative angle; <> 0 to enabled negative angles for energy storage |

Re | Inverter coupling resistance [pu] (0.00 <= Re <= 0.25*Xe) |

Xe | Inverter coupling reactance [pu] (0.04 <= Xe <= 0.40) |

mq | Q-V droop gain. When Vdrpflag<>0, mq represents a per unit virtual impedance [pu] |

kpv | Proportional gain of the voltage controller [pu] |

kiv | Integral gain of the voltage controller (>0) [pu/s] |

mp | Power-Frequency Droop gain [pu] |

Dwmax | Upper limit of Dwm (>=0) [pu] |

Dwmin | Lower limit of Dwm (<=0) [pu] |

kpPLL | Proportional gain of PLL [pu] |

kiPLL | Integral gain of PLL (>0) [pu/s] |

DwPLLmax | Upper limit of the PLL output (>=0) [pu] |

DwPLLmin | Lower limit of the PLL output (<=0) [pu] |

Tp | Time constant of the low-pass filter in the VSM control block (>=0) [seconds] |

H | Inertia time constant [seconds] |

D1 | Damping [pu] |

D2 | Transient damping [pu] |

wD | Angular frequency of the washout block [1/seconds] |

Issmax | Steady state current limit [pu] (Issmax <= 0 is treated as 1/Xe) (Issmax <= 1/Xe) (Issmax <= Ifaultmax) |

Kf | PQFlag determines if Idmax = Kf*Issmax or Iqmax = Kf*Issmax (Kf<=0 is treated 1.0) |

kI | Integral gain for the active current limiting loop [pu/s] |

Ifaultmax | Transient fault current limit [pu]. (If Ifaultmax <= 0 then limit is ignored, but this is not recommended) |

Tpf | Time constant of the low-pass filter for active power measurement (>=0) [seconds] |

TQf | Time constant of the low-pass filter for reactive power measurement (>=0) [seconds] |

TVf | Time constant of the low-pass filter for voltage measurement (>=0) [seconds] |

TIf | Time constant of the low-pass filter for current measurement (>=0) [seconds] |

Ke | Scalar on Idmax for negative real steady state current limitation (0 <= Ke <= 1.0) |

Vpllfrz | Terminal voltage below which special PLL state freezing is implemented (Vpllfrz <= 0.10) [pu] |