Experimental Analysis of the dq0 Stator Current Component Spectra of a 42V Fault-Tolerant Six-Phase Induction Machine Drive with Opened Stator Phases

This paper presents the spectral analysis of the stator phase current and its dq0 components, in a 42V fault-tolerant six-phase induction machine (6PIM) fed by a voltage source inverter (VSI). This machine has symmetrical 60 degrees displacement winding allowing fault-tolerant modes for an electric power steering (EPS) application. The influence of the loss of stator phases in the stator current spectrum is analyzed by studying the behavior of some frequency components which depend on the speed. The fluctuation of these frequencies is examined to evaluate the effect of the torque ripple generated by the negative sequence components in the machine behavior with the loss of one or several stator phases. For this experimental analysis, a six-phase squirrel-cage induction machine of 90W, 17V, 2-poles, fed by VSI, in closed-loop, in normal operation and in faulted mode with the loss of one and two opposite and consecutive phases, has been used.