Characteristic analysis of IPM type BLDC motor considering the demagnetization of PM by stator turn fault

A stator turn fault in a symmetrical three-phase machine cause a large circulating current to flow and subsequently generated excessive heat in shorted turns, generate irregular control current of the three phase leads to demagnetization. The demagnetization of PM occurred distortion of air-gap magnetic flux distribution caused deterioration of their torque, mechanical vibration etc. In this paper, for minimization of mechanical vibration, the optimal PM shape is designed and the effect of the circulating current in shorted turns on the demagnetization of PM and motor performance is analyzed. For this analysis, this paper developed a FE-based simulation model with a stator turn fault modeling. The demagnetization phenomenon in IPM type BLDC is analyzed under continuously controlled 3-phase input current considering the circulating current in shorted turn using the developed transient analysis method.