Internal Fault Analysis of Salient Pole Synchronous Machine Using Modified Winding Function Approach

One of the most common faults that affect the life span and operation of a Salient Pole Synchronous Machine (SPSM) is internal faults. Internal faults are incipient faults in electrical machines which do not affect the operation of machine in initial stage, however slowly they develop into severe faults. An internal fault can damage machine completely in worst case scenario. As a result, internal fault study of SPSM is required to analyze current signatures under fault. In this paper, mathematical modelling of 4-pole SPSM is carried out under stator inter turn fault and various eccentricity fault conditions using Modified Winding Function Approach (MWFA). Current signatures under fault conditions are analyzed using power spectral density analysis. From the obtained fault current signatures, the defective state of SPSM can be identified by continuous monitoring of frequency spectrum of machine currents.