基于电流斜率的SRM功率变换器故障诊断

A Fault Diagnosis of SRM Power Converter Based on Current Slope

功率变换器是开关磁阻电机调速系统重要部件之一,同时也是系统可靠性最弱的环节。针对传统功率变换器故障诊断方法通用性差、需增加额外硬件、无法进行开路器件定位等问题,以不对称半桥式功率变换器为研究对象,改进传统电流传感器安装位置,各相检测电流为绕组和上续流二极管电流之和,通过分析电流斜率在不同故障下的特点,提出一种基于电流斜率的诊断方案。该方案以逻辑信号、检测电流及其斜率为输入建立了故障变量的数学模型,通过模型输出值,即可对功率管开、短路故障进行快速定位,且各相诊断相互独立、不受电机相数及控制方式限制,通用性强;无需增加额外硬件,诊断功能丰富且控制器负担小。仿真和实验验证了方案的有效性。

Aimed at the problems that the traditional power converter fault diagnosis method is poor in versatility,the additional hardware is needed,and the open-circuit devices fail in location,taking an asymmetric half-bridge power converter as the research object,the installation position of the traditional current sensor is improved,through analyzing the characteristics of the current slope under different faults,a diagnostic scheme based on the current slope is proposed.A mathematical model of fault variables is built up based on the input of logic signals,detection current and its slope taken as input by the scheme.Through the output value of the model,the open and short-circuit faults of the power tube can be quickly located,and the diagnosis of each phase is independent of the motor phase.The number and control method are limited,and the versatility is strong;no additional hardware is required,and the diagnosis function is rich and the controller has a small burden.The scheme is valid.