Fault calculations in power system subject to multiple faults

Techniques for considering multiple faults at different locations in a three-phase electrical power system are discussed. The faults may be completely user defined; e.g. a single phase-to-ground fault may be specified on any phase and at any combination of locations. The key idea is to specify the fault in phase quantities and utilize the n-port properties of the [Z] matrices. It is important to note that, in general, multiple faults cannot be dealt with by interconnecting sequence networks and solving the resultant single-phase circuit. The problem is that such interconnections impose additional `across´ constraints between faulted buses. The method is demonstrated by an example