基于振动信号的高压断路器螺栓松动故障诊断研究

Research on Bolt Looseness of High Voltage Circuit Breaker Based on Vibration Signal

断路器在电力系统中肩负着控制和保护的重要任务,加强对断路器机械系统潜伏性故障诊断研究,对提高断路器在运行中的可靠性具有重要意义。文中以ZN98型真空断路器为研究对象,依据其振动强度建立了一套高压断路器振动加速度测试系统,基于MATLAB小波包频带能量分解算法提取故障诊断特征量。以紧固螺栓松动的潜伏性故障为例,分析了不同频段的振动信号能量图谱,提出了一套高压断路器弹簧操动机构螺栓松动潜伏性故障的诊断方法。研究表明,设置单个紧固螺栓故障时,传感器测试位置距离故障螺栓越近所得的特征量阈值越大,应选取特征量阈值的最小值作为测试位置的故障诊断判据;相较于断路器的分闸过程,合闸过程的特征量阈值更能明显准确地反映断路器的机械状态。

Circuit breaker plays the important task of control and protection in the power system.It is of great significance to strengthen the research on the latent fault diagnosis of the mechanical system of the circuit breaker to improve reliability of the circuit breaker in operation.In this paper,type ZN98 vacuum circuit breaker is taken as the research object.According to its vibration intensity,a set of high voltage circuit breaker vibration acceleration test system is established.The fault diagnosis features are extracted based on MATLAB wavelet packet frequency band energy decomposition algorithm.The latent failure of fastening bolt looseness is taken as an example,the vibration signal energy spectrum of different frequency bands is analyzed,and a set of diagnosis method for latent mechanical failure of spring operating mechanism for high-voltage circuit breaker is proposed.The research shows that when a single fastening bolt fault is set,the closer the sensor test position is to the fault bolt,the greater the threshold value of the characteristic value is.The minimum value of the threshold value of the characteristic value should be selected as the fault diagnosis criterion of the test position.The threshold value of the characteristic value of the closing process,compared with the opening process of the circuit breaker,can reflect more clearly and accurately the mechanical state of the circuit breaker.