一种新的中压真空断路器三相同期在线监测方法

针对单独利用短时能量分析法在线监测断路器机械状态时可靠性较低的缺点，该文研究了利用脱扣线圈电流包含的信息来排除机械干扰信号带来的影响，从而提高断路器三相同期性在线监测的可靠性。通过对实际振动信号的分析得出，该方法可以屏蔽掉大范围的干扰噪声，显著提高短时能量法从现场含复杂噪声的振动信号中提取出振动起始时刻的可靠性。并与单独使用短时能量分析法和小波包提取法进行了比较。试验中将该方法应用于ZN12-35型真空断路器分合闸时的振动信号分析，准确得到了空载状态下三相分合闸的同期性。试验结果表明，此改进方法明显提高了短时能量法从振动信号中提取三相同期性的可靠性。

A Novel On-line Monitoring Method for Three Phase Synchronization of Medium Voltage Vacuum Circuit Breaker

Aiming at low reliability in short-time energy analysis method for on-line monitoring of circuit breaker mechanical state, the paper studies the method to eliminate interference noise by using trip coil current signal to improve the reliability of short-time energy analysis method. According to the analysis of vibration signal, this method can significantly improve the reliability of short-time energy analysis method to get the commencement instant of the vibration event from an adverse environment by rejecting most of the noise. The method is also compared with wavelet packets extraction algorithm. The method is tested on a ZN12-35 type vacuum circuit breaker and accurate switching synchronization status of the circuit breaker is obtained. The test results show that the new method obviously improve the accuracy of short-time energy analysis method to get the switching synchronization status of circuit breaker.