基于电流畸变特性的整流器开路故障诊断系统设计与实现

Design and Realization of Open-circuit Fault Diagnosis System for Rectifier Based on Current Distortion Characteristics

半导体开关是影响电压源整流器VSR(voltage source rectifier)系统整体故障率的重要因素。为此,提出一种基于电流畸变特性的三相开路故障诊断系统,该系统由诊断模块、寄存器模块和决策模块组成。诊断模块使用滞环比较器来判断电流的变化趋势,从而诊断开路OC(open-circuit)故障;寄存器模块用于实现多开关OC故障诊断;决策模块用于输出最终结果。实验结果表明,该方法能够正确实现包括6种单开关故障和15种不同的双开关故障在内的故障诊断,故障诊断准确性好。此外,所提方法在负载突变、不同功率因数、电网电压不平衡和畸变以及不同的交流滤波器结构条件下均具有良好的抗干扰性能和较强的鲁棒性,平均诊断时间仅为3.68 ms。

The semiconductor switch is an important factor affecting the overall failure rate of a voltage source rect-ifier(VSR)system.In this context,a three-phase open-circuit(OC)fault diagnosis system based on current distortion characteristics is proposed,which consists of a diagnosis module,a register module and a decision module.The diagnosis module uses a hysteresis comparator to determine the changing trend of current,so as to diagnose one single OC fault.The register module is used to realize the multi-switch OC fault diagnosis,and the decision module is used to output the final result.Experimental results show that the proposed method can correctly realize the diagnosis of faults,including 6 kinds of single-switch fault and 15 kinds of diflerent double-switch faults,with a satisfying fault diagnosis accuracy.In addition,the proposed method has a good anti-interference performance and a strong robustness under conditions of load mutation,diflerent power factors,unbalanced and distorted grid voltage,and difierent AC filter structures.Moreover,the average diagnosis time is only 3.68 ms.