光纤位移传感器在断路器在线监测系统中的应用

The Applications of the Optical Fiber Displacement Sensor in On-line Monitoring System of Circuit Breaker

针对以往用于断路器在线监测位移传感器的不足,本文提出了使用光纤位移传感器测量断路器动触头行程,达到精度高、干扰少的目的。提出一种基于希尔伯特-黄变换的断路器刚合点分析方法,利用经验模态分解得到包含速度信号局部特性的本征模态函数分量,根据速度突变点的特征,利用方差贡献率选择本征模态函数分量,经过希尔伯特变换得到瞬时幅值,该曲线的特征点即断路器刚合点。实验证明,该方法能够有效提取断路器的刚合点,耗时少、结果准确,可为断路器故障诊断提供可靠依据。

Fiber optic displacement sensor is introduced to measure the trip of the circuit breaker＇s moving contact against deficiencies of the displacement sensors used by previous online monitoring system, which leads to high-accuracy and low interference. An analysis method based on Hilbert-Huang Transform to extract moment-close point is put forward. The intrinsic mode function （IMF） component which contains speed signal partial characteristic is extracted by empirical mode decomposition （EMD）. The IMF component is selected by file variance contribution rate according to the speed characteristic of the moment-close point. Thus the selected IMF component can be analyzed by instantaneous amplitude after Hilbert transform, whose feature point is the moment-close point of the circuit breaker. The experiment results shows that the analysis method could extract the moment-close point effectively and accurately, providing credible information for the fault diagnosis of circuit breaker.