Non-synchronous Test System Of Vacuum Circuit Breaker Based On Vibration Signal

Non-synchronous is one of important mechanical characteristics of the circuit breaker,Asynchronous closing of the circuit breaker makes overvoltage more likely to occur,moreover affects motors’ starting and the usage of transformers. Nowadays revolutionaryadvances in the construction of smart grid have led to the development of intelligent circuitbreakers, and advances of online monitoring technique will be the key to successfuldevelopment of intelligent circuit breaker. Barely involve electrical quantities and goodanti-interference ability compared with other online monitor technique makes mechanicalvibration signal measurement superiorly.According to the characteristics of vibration signal, selecting acceleration sensor tocollect the vibration signal of circuit breakers, developing a data acquisition card with thecore of DSP chip, and realize USB communication with host PC based on the CY7C68001chip. The host PC uses LabVIEW programming to test asynchronism characteristics ofcircuit breakers.According to characteristic of the test on asynchronism of circuit breakers, proposingindependent component analysis method suitable for the system with multi-input and multi-output. Extracting vibration signals of the three-phase contact from the mixed vibrationsignals, and then analyze separately. The vibration signals generated by closing and openoperation of Vacuum circuit breaker are mutually independent and non-Gaussian.Collecting vibration signals with three acceleration sensors to satisfy three basic conditionsof independent component analysis method. Verifying the correctness and feasibility ofindependent component analysis method with MATLAB simulation.Three steps needed to analyze Vibration signals: First, Applying wavelet de-noisemethod to remove noise interference and random vibration; Second, Using independentcomponent analysis method for signals blind source separation, Extracting vibration signalof each phase contact from the mixed vibration signals; Third step, Applying short-termenergy analysis to isolated single-phase vibration signal, then Obtain asynchronism lag inthree-phase after determing the time of closing operation.