Design and evaluation of voltage measurement-based sectoral diagnosis method for inverter open switch faults of permanent magnet synchronous motor drives

A sectoral diagnosis method for open switch faults of inverter-fed permanent magnet synchronous motor (PMSM) drives have been described. The proposed diagnosis method defines separate residuals for each of the six switches as a sectoral average of the difference between a reference and measured pole voltage instead of direct use of the instantaneous difference, which has varying AC quantity within one cycle of rotation. How to determine plausible thresholds is described and the effectiveness and limitation of the proposed method are analysed. Several sets of experimental results validate the detection and isolation capability of the proposed method.