中性点接地三相桥式固态限流器故障诊断方法

Fault Diagnosis Method for Neutral Grounding Three-Phase Bridge Type SSFCL

探讨了中性点接地三相桥式固态限流器桥路故障诊断方法。仿真研究表明,通过监测、分析桥路直流电感电流和2个续流管电流,能够有效区分不同类型的桥臂开断与直通故障,实现对桥路故障类型的诊断;通过对桥路直流电感电流波形和2个续流管电流波形及其傅里叶变换分析,可计算出直流分量、基波分量和二次谐波分量,根据其数值特点,实现对故障桥臂的定位。该方法具有监测量小、故障特征明显、判据简单等特点,可用于在线监测、诊断固态限流器整流桥桥臂故障。

This paper presents a fault diagnosis method for neutral grounding three-phase bridge type solid-state fault current limiter （SSFCL）. Simulation studies show that based on monitoring and analysis of current of DC reactor and two free-wheeling diodes for the bridge, different type faults of bridge-arm breaking and through can be effectively distinguished so as to implement diagnosis of bridge fault type. With current waveforms of the DC reactor and two free-wheeling diodes and their Fourier analysis, the DC, fundamental and second harmonic components can be calculated to locate fault bridge-arm. This method has many advantages, such as small monitoring amount, obviousness of fault characteristic, the simple criterion, etc. It is conducive to realize on-line monitoring and fault diagnosis for arms of rectifier bridge of SSFCL.