Intermittent Misfiring Default Detection and Localisation on a PWM Inverter Using Wavelet Decomposition

This paper presents a method to detect and localize intermittent misfiring default on a Pulse Width Modulation (PWM) inverter supplying a squirrel cage induction machine. The proposed method is based on the Discrete Wavelet Transform (DWT) technique to analyse stator current signals. The intermittent misfiring detection is performed thanks to the Daubechies wavelet mother in high frequency bands of the stator current signal. The localisation of the phase where the intermittent misfiring occurs is determined by a statistic approach. This approach is based on the computing of mean power characteristics of the detail signals which are obtained from the stator current wavelet decomposition.