Analysis of Simultaneous Ground and Phase Faults on a Six Phase System

Multiphase transmission lines are a serious contender to the conventional three phase lines. The variety of faults on multiphase systems is far greater than on 3 phase systems. From the operational point of view the subject of fault analysis or multiphase systems assumes great importance. Two matrices called ´phase fault co-efficient matrix´ and ´ground fault co-efficient matrix´ have been defined. Their elements can be written for each type of fault. With the help of these two matrices a single algebraic equation is sufficient for calculating all sequence currents following any sustained simultaneous ground and phase fault. From the single equation the sequence currents are written in the format ## with unity as the second element on the RHS. Here z and e1 are the first sequence impedance and e.m.f., respectively. An inspection of a0, a2 ... a5 and z´ at once suggests the manner in which the sequence networks must be connected to simulate a given fault.