A noninvasive approach for high-voltage (HV) circuit breaker (CB) diagnosis, based on the time–frequency analysis of the transient electric fields (E-fields) radiated due to switching operations outside the enclosure [switching transient E-fields (STEFs)], is presented in this paper. By use of a synthetic test platform, this paper measures the STEFs generated by CBs working in both normal and fault status and analyses their primary parameters, such as the amplitude, the center frequency, and the number of pulses. The correlation between the different working status of the CBs and the time–frequency characteristics of their STEFs is established. Based on the comparison and analysis of the main features, the STEFs could reflect the operating states and serve as an indicator of the early insulation defect of the HV CBs. The proposed defect detection method has been validated experimentally, which makes the most of the high changing rate of the induced current on the CB enclosure that itself is a weak signal and hard to capture by traditionally adopted means. This method can further be a useful reference of defect or fault diagnosis for the switchgear in operation.

中文翻译：

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基于开关瞬态电场时频分析的高压断路器故障检测

一种用于高压 (HV) 断路器 (CB) 诊断的非侵入性方法，基于对由于外壳外的开关操作而辐射的瞬态电场 (E 场) 的时频分析 [开关瞬态电场 (STEF) )]，在本文中介绍。本文利用综合测试平台，测量CB在正常和故障状态下产生的STEF，并分析其主要参数，如幅度、中心频率和脉冲数。建立了CB不同工作状态与其STEF时频特性之间的相关性。通过对主要特性的比较分析，STEF可以反映高压断路器的运行状态，作为判断高压断路器早期绝缘缺陷的指标。所提出的缺陷检测方法已经通过实验验证，它充分利用了CB外壳上感应电流的高变化率，而CB外壳本身是一个弱信号，并且难以通过传统方式捕获。该方法还可为运行中的开关柜进行缺陷或故障诊断提供有益的参考。