Modelling and experimental validation of internal short-circuit fault in salient-pole synchronous machines using numerical gap function including stator and rotor core saturation

In this study, the winding function method is modified and used to calculate the machine inductances in two different cases, namely, a healthy case and a short-circuited stator winding case. For the first time, a numerical air-gap function is used in addition to a model of the air gap of salient-pole machines which considers the stator slot effects. The modified winding function (MWF) method introduced here is more precise when compared with previous methods. This MWF enables one to compute the air-gap function more accurately. Also a mathematical model that allows taking stator and rotor core saturation into account in both healthy and faulty conditions is presented in this study. Stator and rotor winding currents in healthy and faulty condition, obtained from experimental results, are compared with simulation results to verify the accuracy of the proposed method.