Two-Phase Four-Switch Fault-Tolerant Control Of Permanent Magnet Synchronous Motor Based On Model Predictive Control

Permanent Magnet Synchronous Motor(PMSM)is widely used in the field of electric vehicle driving due to its stable performance,high efficiency,and high-power density.As the core component of its driving system,the reliability of the power switching devices in the inverter has always been a concern.Due to the complex internal structure of the inverter and its special and harsh operating environment,the failure rate of the switching devices is extremely high.Once a fault such as a short circuit or an open circuit occurs,it may pose a serious threat to the safe operation of the vehicle.Therefore,exploring a feasible,efficient,and practical inverter fault-tolerant control strategy that enables the PMSM drive system to continue to operate in the event of a single-phase fault is of great practical significance for improving system reliability and stability,ensuring the safety of people and property.This paper focuses on the research of fault-tolerant control technology for PMSM drive system.Specifically,it addresses the problem of inverter single-phase faults caused by damage to switching devices.By combining the two-phase four-switch fault-tolerant topology with model predictive control,a fault-tolerant control scheme based on model predictive control technology is designed.The main research contents are as follows:(1)A mathematical model of PMSM is established in the natural coordinate system,two-phase rotating coordinate system,and two-phase stationary coordinate system,respectively.The principles of direct torque control technology and model predictive control technology are studied and analyzed,and the two methods are combined to design a model predictive direct torque control strategy for PMSM.A simulation model of the motor speed control system based on this strategy is established in Matlab/Simulink,and the simulation output waveform proves the effectiveness of the designed control strategy.(2)A mathematical model of the PMSM drive system based on the two-phase fourswitch fault-tolerant topology is constructed to address inverter single-phase faults.The working principle,switching status,and corresponding voltage vector relationship of the two-phase four-switch fault-tolerant inverter are analyzed.Based on the model predictive direct torque control strategy,a fault-tolerant control strategy for the two-phase four-switch fault-tolerant PMSM drive system is designed.A simulation model of the motor speed control system with fault-tolerant topology is built in Matlab/Simulink,and the output waveform demonstrates the effectiveness of the designed fault-tolerant control strategy.(3)A real-time simulation system based on d SPACE is designed for the fault-tolerant control experiment of the PMSM drive system.The overall structure and hardware circuit design of the platform are introduced.Simulations of single-phase faults of the PMSM are performed on the platform,and the designed fault-tolerant control strategy is experimentally validated.