A voltage based approach for fault detection and separation in permanent magnet synchronous machines

摘要

Different faults in Permanent Magnet Synchronous Machines will cause various and independent changes to the machine magnetic flux distribution, which will cause different changes to the machine parameters and performance. These changes will be reflected in the machine flux linkages, which can be determined from the machine voltages. In this paper, a method is proposed to detect and separate three types of faults in Permanent Magnet Synchronous Machines: static eccentricity, demagnetization and turn-to-turn short circuit. The proposed method is based on using the direction of the shift in the commanded d and q axis voltages while the machine is operating at steady state. Simulation tests using Finite Element Analysis software (MAGSOFT-Flux2D) were performed under healthy and faulted conditions on a 3 phase 10-pole fractional slot concentrated winding Permanent Magnet Synchronous Machine. Experimental tests were carried out and compared with Finite Element Analysis for the same machine under demagnetization and turn-to-turn short circuit faults. The effects of the speed and temperature variations were simulated to validate the detection method under different operating conditions.