Analysis of unbalanced polyphase networks by the method of phase co-ordinates. Part 2: Fault analysis

A general analysis of power-system polyphase networks under fault conditions is developed in terms of the phase-co-ordinate representation. It is shown that the method requires only the assembly of the nodal phase admittance or impedance matrices from connection tables, and either the subsequent solution of sets of linear algebraic equations subject to constraints, or the use of the superposition principles of the generalised Norton theorem. By these techniques, the problems of multiple unbalanced faults on unbalanced systems can be analysed with no more difficulty than balanced 3-phase faults on balanced systems.