感性非接触式电缆故障在线诊断方法研究

提出采用感性耦合技术实现非接触式电缆故障在线诊断的方法,解决现有非接触式诊断中容性耦合信号衰减量大、诊断效果不佳问题。相比于接触式诊断,非接触式诊断避免了诊断装置与待测电缆的电气连接问题,更安全更方便。首先基于感性耦合主要影响因素(互感、宽带信号耦合能力),理论分析理想条件下感性耦合与接触式直接注入式诊断效果一致时,耦合器的材质及参数特性,对感性耦合器进行了分析设计;进而分析和仿真验证即便在耦合器实际寄生参数影响下,其衰减程度依旧小于容性耦合,最后通过实验验证感性非接触式故障诊断检测率可达93%以上、定位误差在0.42 m以内,该方法具有高的实际推广应用价值。

Research on inductive non contact online cable fault diagnosis method

This paper proposes an online diagnosis method that adopts inductive coupling technique to realize non contact cable fault diagnosis; the method solves the problems of large signal attenuation of capacitive coupling and poor diagnosis effect in existing non contact detection approaches. Compared with contact diagnostic methods, non contact diagnosis approaches avoid the electrical connection between diagnostic device and the cable under test, and is safer and more convenient. Firstly, based on the main factors (mutual inductance, broadband signal coupling ability) that affect inductive coupling method, the paper analyzes theoretically the materials and parameter characteristics of the coupler under ideal condition in which the diagnosis effects are the same for inductive coupling method and contact, direct injection method; the inductive coupler is analyzed and designed. Then, theoretical analysis and simulation verify that even if the inductive coupler suffers from the influence of actual parasitic parameters, the signal attenuation of inductive coupling is still less than that of capacitive coupling. At last, experiment results verify that the detection rate of inductive non contact cable fault diagnosis reaches to above 93%, the positioning error is less than 0.42 meters. The proposed method has great actual application value.