EXACT MODELING AND SIMULATION OF SATURATED INDUCTION MOTORS WITH BROKEN ROTOR BARS FAULT USING WINDING FUNCTION APPROACH

Winding function method (WFM) provides a detailed and rather simple analytical modeling and simulation technique for analyzing performance of faulty squirrel-cage induction motors (SCIMs). Such analysis is mainly applicable for designing on-line fault diagnosis techniques. In this paper, WFM is extended to include variable degree of magnetic saturation by applying an appropriate air gap function and novel techniques for estimating required saturation factor and angular position of the air gap flux density. The resultant saturable winding function method (SWFM) is properly applied for analyzing SCIMs with broken rotor bars and for identifying the saturation effect on the related fault indexes. Comparing simulation results to the corresponding experimental results show higher accuracy of the SWFM. This means that more precise fault diagnosis techniques can be designed by using the proposed saturable modeling technique.