矩阵变换器开路故障分析及诊断方法

Analysis and diagnosis method of open-circuit faults in matrix converter

矩阵变换器(MC)故障开关的可靠诊断和定位是故障隔离技术和故障后容错技术高效实现的基础。基于矩阵变换器-永磁同步电机(MC-PMSM)系统仿真平台,定性分析MC中功率开关开路故障影响区间以及MC-PMSM系统故障表现,并提出一种新颖的MC开关开路故障诊断方法—调制误差电流法。故障诊断算法分2步实现:第1步利用电机电流与MC输出电流的绝对差值诊断故障相,缩小故障开关定位范围;第2步结合MC开关调制信号定位故障开关的具体位置。仿真结果验证所提出的故障诊断算法的实时性和可靠性,并能够在电机调速和负载突变等非稳定情况下有效避免误诊断。

Reliable diagnosis and location of matrix converter failure switch is the basis for efficient implementation of fault isolation and fault-tolerant technology. Based on the simulation platform of MC-PMSM system, an analytical work concerning the affected interval of open-circuit switches in MC and faulty behaviors of MC-PMSM system was presented. A new method for detecting and identifying open-circuit switch was proposed. The algorithm based on modulated error current was implemented in two stages： In the first stage, the faulty phase was diagnosed by measuring the differential values between motor currents and MC output currents, which reduced the range of possible faulty switches from nine to three. In the second stage, the MC switch modulated signals were combined to locate faulty switch. The validity and reliability of the proposed method were verified by the simulation results, which demonstrates that the strategy can avoid misdiagnosis under the unstable situations.