Transient 3-D Lumped Parameter and 3-D FE Thermal Models of a PMASynRM Under Fault Conditions With Asymmetric Temperature Distribution

This article proposes a novel transient 3-D lumped-parameter (LP) thermal model and a 3-D finite-element (FE) thermal model of a triple redundant nine-phase permanent magnet-assisted synchronous reluctance machine to predict the asymmetric temperature distribution under various fault conditions. First, the predicted transient and steady-state temperatures are compared between the 3-D LP and the 3-D FE thermal models under fault conditions with uneven loss distribution. Also, the temperatures predicted by the LP and FE thermal models, which account a number of practical issues are comprehensively compared with the test results under healthy and short-circuit fault conditions. The relative merits of the two thermal models are discussed. It is shown that both models have reasonable accuracy in predicting the machine's thermal behavior under fault conditions and can be chosen according to the requirements.