Field reconstruction for modeling multiple faults in permanent magnet synchronous motors in transient states

Abstract

Conventional field reconstruction model (FRM) for electrical machines has proved its main strength in efficient computations of magnetic fields and forces in healthy permanent magnet synchronous machines (PMSM) or faulty machines in steady states. This study aims to develop a magnet library of different magnet defects and include inter-turn short-circuit (ITSC) in the FRM for PMSM. The developed FRM can model a combination fault between ITSC, and magnet defect in a PMSM in transient states. Within the framework, an 8-turn ITSC was modelled in both finite element analysis (FEA) and FRM, and then identified by the extended Park's vector approach. The air-gap magnetic field reproduced by the FRM shows a good agreement with the result from time-stepping FEA. The computation speed is over 1000 times faster than an equivalent time-stepping FEA. The suggested FRM allows for quickly understanding effect of faults in the rotor and stator on the air-gap magnetic flux density and identifying unique signatures for such defects.