Fault tolerant strategies under open phase fault for doubly salient electro-magnet motor drives

In this paper, the fault tolerant system for doubly salient electro-magnet motor(DSEM) drives have been proposed to maintain the control performance under open phase faults of inverter. The proposed fault tolerant system provides compensation for open-circuit faults in power inverter. The fault identification is quickly achieved by phase current and voltage changes between lower legs and middle point of DC-link. The drive system after fault identification is reconstructed by the FSTP(four-switch three-phase) topology connecting a faulty leg to the middle point of DC-link using bidirectional switches. The fault tolerant system quickly recovers the control performance by short detecting time. Experiments confirm the feasibility of the proposed fault tolerant system.