Failure characteristics of motor system using distributed inverters for PMSM

A motor control system driven by multiple distributed inverters has been proposed until now to improve the robustness and the fail-operational control performance of motor drivers just after some of the inverters break down. Its failure characteristics are examined and analyzed by some experiments using a permanent magnet synchronous motor (PMSM) with eight poles and twelve windings. The proposed control system consists of four current controllers and inverters which are installed in parallel between the velocity controller and the motor. In the experiment, the proposed system could keep the commanded velocity without any instability of the system even after three inverters failed at the same time.