基于T型逆变器的APF故障诊断与容错控制

Fault Diagnosis and Fault Tolerant Control for APF Based on T-Type Inverter

逆变器是有源电力滤波器(activepowerfilter,APF)的核心部件,是保证APF稳定运行的基础。T型逆变器具有电路损耗低、输出波形畸变率低等优点,正获得越来越广泛的应用。该文分析T型三电平逆变器功率器件开路故障后的运行状态,通过空间矢量脉宽调制(spacevectorpulse widthmodulation,SVPWM)和逆变器输出电流完成逆变器功率器件开路故障诊断。结合APF的运行特点,利用T型三电平逆变器拓扑冗余和三电平SVPWM的矢量冗余及矢量合成分别提出1种垂直桥臂器件故障容错运行策略和2种水平桥臂容错运行策略。搭建仿真模型及实验平台对提出的容错策略进行验证,仿真和实验结果证明了该容错策略算法的有效性。

Inverter is an important equipment to improve power quality. The inverter is the core component of active power filter(APF), which is the basis of ensuring the stable operation of the APF. The T-type three-level inverter has been widely used in active power filter because of its advantages of low circuit loss and low distortion. In this paper, the operation state of open-circuit fault in power device of T-type three-level inverter was analyzed, space vector pulse width modulation(SVPWM) and the output current of inverter were used to detect the open-circuit fault of power device in the inverter. Combined with the operating characteristics of APF, the redundancy of T-type three-level inverter topology and three-level SVPWM and vector synthesis were used to propose one kind of fault-tolerant operation strategy for switch device in vertical bridge arm and two kinds of fault-tolerant operation strategy for switch device in horizontal bridge arm, respectively. Finally, the simulation model and the experimental platform were established to verify the proposed fault-tolerance strategy. The results of the simulation and experiments proved the effectiveness of the fault-tolerance strategy.