Research On Vibration Monitoring Method For Mechanical Fault Of High Voltage Circuit Breaker

High-voltage circuit breaker(HVCB) plays an important role in the control and protection of power systems. It's function is equivalent to a switch, closing the circuit to make it into the normal grid operation, cuting off the fault circuit in time. Mechanical failures of HVCBs are frequently occurring on site of power system, which bring economic losses and impact on power system stability. Because vibration signals contain plentiful condition information and can be obtained invasively, fault diagnosis via vibration monitoring is a potent technique for mechanical condition estimation of HVCBs, which is competent to detect and prevent impending failures in advance. This paper designs on-line monitoring and fault diagnosis system based on vibration signal of HVCBs, and empirical mode decomposition(EMD) method was applied to the handling of vibration signal of HVCBs, extracting the corresponding state characteristic values and combining support vector machine(SVM) to diagnose the faults.Vibration signal of HVCBs is determined by its internal transmission for a series of actions arising from the superposition of the shock wave, and the vibration signal contains a rich array of device status information. The use of modern signal processing techniques to extract characteristic values of faults, is a hot research topic of HVCBs diagnosis. This article describes the empirical mode decomposition(EMD) principle, the use of Hilbert transform to extract the envelope information of the IMF component, and the use of Time segmentation of IMF component to extract the energy entropy characteristic value of vibration signal. then use the support vector machine to classify the fault, so as to realize the fault diagnosis.In this paper, the characteristics and mechanism of high voltage circuit breakers are analyzed,and the EMD method is simulated to extract the characteristic value;then the hardware and software system of the fault diagnosis of HVCBs is designed.