A Generalized Open-Phase Fault Detection Technique for Symmetrical Multiphase Machines Using Zero-Sequence Current Constraints

Due to their inherent fault tolerance capability, multiphase drives are favored in applications with high-reliability requirements. In order to further enhance the fault-tolerant performance, many study efforts have been devoted to different postfault control strategies. In most of the strategies, knowledge of the fault type and location is required prior to the fault-tolerant operation. Therefore, fault detection is an indispensable procedure. Making use of the zero-sequence current constraints, this paper proposes a generalized method to detect and locate the open-phase faults in symmetrical multiphase machines. This method is simple and can be applied to symmetrical multiphase machines with any phase numbers. Experimental results prove the fast detection speed and robustness of the proposed method even in machine transients (such as speed and torque steps) and multiple-open-phase faults.