Modified space vector modulation for fault tolerant control of PMSM drive

The paper presents fault tolerant control algorithms of modified space vector pulse width modulation (SVPWM) for three-phase inverter supplies a PMSM in case of failure of one transistor leg. Fault tolerant inverter structure with four-switch is analyzed with taking into account the non-ideal DC link. Calculations of the desired voltage vector in the PMSM drive are presented. An optimal voltage vector sequence and scaling factors for SVM has been derived to synthesize the reference voltage vector in each sampling period. It has been proved by simulation results that four-switch inverter fed PMSM is able to operate steadily and with acceptable static and dynamic properties under the proposed approach.