三相四开关容错逆变器的PMSM驱动系统FCS-MPC策略

针对三相四开关容错逆变器的永磁同步电机(PMSM)驱动系统,基于模型参考自适应(MRAS)观测器,提出一种有限控制集模型预测控制(FCS-MPC)策略。考虑温度变化对永磁磁链影响,采用MRAS技术,实现了对永磁磁链的在线辨识;同时考虑降低逆变器开关频率的需求,设计开关频率可优化的FCS-MPC系统目标函数。与常规FCS-MPC方法比较,本方法可以有效减小系统控制过程的计算量,与此同时,本方法中的电流反馈特性可对四开关逆变器直流母线电容分压不平衡形成的不利影响实现自动抑制。仿真结果表明,本方法能够保证四开关容错逆变器驱动的PMSM系统持续稳定运行、具有良好运行性能,并能明显降低逆变器功率管的开关频率。

Finite-control-set model predictive control for PMSM systems driven by three-phase four-switch fault-tolerant inverter

Based on three-phase four-switch inverter, a finite-control-set model predictive control ( FCS-MPC) strategy is proposed for permanent magnet synchronous motor ( PMSM) drive system with MRAS observer.Because of the reason that permanent magnet flux linkage is varied with temperature change, a MRAS observer was designed to identify permanent magnet flux online.In order to improve the inverter reliability, its switch frequency optimization was taken into account in designing cost function of FCS-MPC.Compared with conventional FCS-MPC, the proposed one in this paper obviously reduces the com-putation amount of control system.Meanwhile the current feedback characteristic provided by this method can automatically suppress the adverse effect resulting from two capacitor voltages' unbalance of DC bus terminal in three-phase four-switch inverter.Numerical simulation results illustrate that the proposed FCS-MPC can enable whole system to not only run continuously and stably but also achieve satisfactory torque and speed control as well as reduce the average inverter switching frequency.