五相永磁同步电动机单相开路故障的容错控制策略

Fault-tolerant Control Strategy for Five-phase Permanent Magnetic Synchronous Motor Under Single Phase Open-circuit Fault Condition

为使五相永磁同步电动机(five-phase permanent magnetic synchronous motor,FPMSM)在发生单相开路故障时仍能继续提供平滑转矩,提出一种基于解析法的容错电流优化控制策略。利用缺相状态下的扩展派克变换矩阵,分别推导了基波和3次谐波同步旋转坐标系下的转矩和铜损方程。针对磁场为正弦和含3次谐波两种情况,分别提出了仅施加基波电流和注入3次谐波电流消除转矩脉动的解析方法,并从最大转矩电流比和最大转矩的角度分别提出了铜损最小和铜损相等原则的容错电流优化方法。最后,得到了适用于各种磁场类型及优化目标的容错电流通用在线生成方法。仿真和实验结果表明所提容错算法可实现对电机转矩和转速的无扰控制。

To obtain a post-fault smooth motor torque and guarantee safe drive operation after fault occurrence, the novel fault-tolerant current control strategies for five-phase permanent magnetic synchronous motor under single phase open-circuit fault condition was presented. By adopting post-fault extended transformation matrixes, torque and copper loss equations at fundamental and third harmonic synchronous rotating coordinates were deduced respectively. According to the two cases of back-EMF with and without third harmonic component, analytical methods to eliminate the torque pulsation by applying fundamental current only and with third harmonic current injection were proposed. Also, from the perspectives of maximum torque per ampere and maximum total torque, the corresponding analytical optimization methods were proposed further. A universal online generation technique of fault-tolerant current applicable to different types of air gap magnetic field and optimization objectives was designed. A good match between analytical predictions and results of both simulations and experiments validates the proposed current control strategies.