# Triple and Quadruple PI Lines

The models of triple and quadruple PI lines are a generalization of the coupled PI line model. They represent respectively 3 and 4 three phase circuits. The quadruple model with fault is also available.

**Triple and Quadruple PI Lines Icons and Diagrams**

**Parameter Description**

The parameters for triple and quadruple PI lines are the same as for those for simple PI lines, except that the dimensions of the R, L and C matrices representing the impedances and admittances of the conductors are 9x9 and 12x12. Since these matrices are large, the option that allows calculate the values of the parameters from EMTP or Inpurdue files is quite interesting; it allows users to avoid the tedious task of re-transcribing the values and possible resulting errors.

**List of Available Signals**

As for a coupled PI line, there is no line signal available for triple and quadruple PI lines. Only the fault signals are available.

**Fault Signals**

V(a, b, c)_FLT1_line label | Voltage on fault bus of line 1 (volt) |

V(a, b, c)_FLT2_line label | Voltage on fault bus of line 2 (volt) |

V(a, b, c)_FLT3_line label | Voltage on fault bus of line 3 (volt) |

V(a, b, c)_FLT4_line label | Voltage on fault bus of line 4 (volt) |

I(a, b, c, n)_FLT1_line label | Fault current of line 1 (ampere) |

I(a, b, c, n)_FLT2_line label | Fault current of line 2 (ampere) |

I(a, b, c, n)_FLT3_line label | Fault current of line 3 (ampere) |

I(a, b, c, n)_FLT4_line label | Fault current of line 4 (ampere) |

CMD(a, b, c, n)_FLT1_line label | Command for states of phase and ground breakers of line1 |

CMD(a, b, c, n)_FLT2_line label | Command for states of phase and ground breakers of line 2 |

CMD(a, b, c, n)_FLT3_line label | Command for states of phase and ground breakers of line 3 |

CMD(a, b, c, n)_FLT4_line label | Command for states of phase and ground breakers of line 4 |

Control Panels for PI Lines - Triple, Quadruple and Quadruple with Fault

**Line Data**

Since these models are a generalization of the coupled PI line, the data are calculated in the same way.