基于振动信号短时能熵比与DTW的高压断路器状态评估及故障诊断

State Evaluation and Fault Diagnosis of High-voltage Circuit Breaker Based on Short-time Energy Entropy Ratio of Vibration Signal and DTW

针对高压断路器在线监测问题,提出了一种基于短时能熵比与动态时间规整(dynamic time warping, DTW)算法的高压断路器状态评估及故障诊断方法。首先对断路器正常工况下的振动信号与未知工况下的振动信号分别进行分帧,依次计算2组振动信号的短时能熵比;然后以正常工况信号计算得到的短时能熵比作为基准向量,以未知工况信号计算得到的短时能熵比作为测试向量输入DTW,得到2个输入向量的最优匹配路径;最后根据匹配路径的变化曲线判断断路器的工作状态。为验证该诊断方法的优越性,将原始信号及原始信号的短时能量作为输入向量输入DTW,结果表明,以短时能熵比作为DTW输入向量的故障诊断方法仅需1组正常工况下的振动信号作为基准,可快速、准确、直观地对断路器的运行状态进行评估判断,并可应用到高压断路器的在线监测中。

Aiming at the problem of on-line monitoring of high-voltage circuit breakers, we proposed a state evaluation and fault diagnosis method for high-voltage circuit breakers based on short-time energy entropy ratio and dynamic time warping(DTW). Firstly, vibration signals of the normal state and unknown states were framed to calculate short-time energy entropy ratio, respectively. Then, a short-time energy-entropy ratio calculated from normal state sample was used as the template, and the ratio calculated from unknown state samples was input to DTW for tests. Finally, the operating state of circuit breaker could be judged by observing the changing curve of matching path. In order to verify the superiority of the method, the original signal and the short-time energy of original signals were input to the DTW as input vectors for comparison. The results show that, by only taking one signal of normal state as the template, the method in which the short-time energy entropy ratio is used as a DTW input vector can be adopted to evaluate and judge the operating state of circuit breaker quickly, accurately and intuitively, suggesting that the proposed method can be applied to the online monitoring of the high voltage circuit breakers.