埋め込み磁石型同期電動機の磁石の一部が故障したときの特性解析と診断，日本AEM学会誌，vol.19，no.2，pp261-266，2011
Abstract: Since a high driving reliability is required to interior permanent magnet synchronous motors, the detection of failure of the demagnetization of permanent magnets is becoming important. This paper clarifies the characteristics of the motor with demagnetized permanent magnets. It also shows that the Fourier analysis and the Wavelet analysis of the amplitude of two-phase current are useful to show the difference of the magnetization of permanent magnets, and thus they can be used as the failure diagnosis method of the demagnetization of permanent magnets.