Internal fault simulation in synchronous machines

This paper describes a synchronous machine model that can be used to simulate internal fault waveforms for power system protection studies. The need to develop the machine model in the direct phase domain is explained and a method to calculate the inductances involving the faulty windings is outlined using a four pole lap wound machine. The machine equations are then solved using a suitable numerical technique. Comparisons are made between the simulated waveforms and recorded waveforms to verify the accuracy of the model.