A Review of Fault-Tolerant Operation Technologies for Multiphase Motors

Multiphase motors offer advantages such as high reliability, flexible control methods, and the ability to operate at high power levels, making them suitable for applications with high reliability requirements, such as aerospace, ship propulsion, and electric vehicles. Fault-tolerant operation refers to the ability of motors to continue running despite the presence of faults, achieved by employing special hardware structures or control strategies. In the aspect of fault tolerance, multiphase motor drive systems distinctly outperform traditional three-phase drive systems. This paper reviews and summarizes recent studies on fault-tolerant operation technologies for multiphase motors, categorizing fault tolerance topologies into two categories: motor winding topologies and inverter topologies. It provides a classified overview of design techniques for fault-tolerant control based on vector control, direct torque control, and model predictive control. The paper also summarizes optimization control strategies for current and pulse-width modulation (PWM) strategies within the context of fault-tolerant operation. Subsequent discussion focuses on the speed-sensorless control of multiphase motors during fault-tolerant operation, leveraging signal injection methods and observer-based methods. Additionally, the necessity of parameter identification for multiphase motors under fault-tolerant operation is discussed. After presenting case studies of fault-tolerant operation scenarios for multiphase motors, the paper summarizes the current status of research in this field, and concludes with prospects for future developments.