Robust operation of double-output AC machine drive

This paper presents strategies for maintaining operation of a double-output AC machine drive in the presence of various component failures. With a short/open-switch fault, the drive is capable of operating the AC machine at a reduced power capability by creating an artificial neutral. The procedures of mode transition are shown to depend on the system configuration. This operating method can be applied to both induction and permanent magnet synchronous machines as long as they can sustain a few cycles of increased current. Robust operation of the drive in case of short-circuit fault in the phase winding is also presented. It is also demonstrated in this paper the operating method when one of the two isolated DC sources is interrupted. This work further discusses the two-phase operation mode in which one faulted phase is isolated from the remaining portion of the circuit. Simulink simulation results are presented.