Control strategies for fault tolerant PM drives using series architecture

A fault tolerant drive based on a series architecture (one or two DC sources, two voltage source inverters and a PMSM) is studied in this paper. Three different operating modes are considered: normal mode, open-circuit degraded mode and short-circuit degraded mode. For each case, an adapted torque control strategy is proposed, applied and tested. The main contribution lies in the control strategies for degraded modes. For the open phase mode, different operating criteria are considered. For short-circuit faults, two solutions are proposed. The proposed strategies in this paper are tested on a drive realized for aerospace applications. The proposed techniques here allow operating under fault conditions in real-time and their implementation is easy. The experimental results show the validity of the proposed methods.