Mechanical state detection of high voltage circuit breaker based on optimized VMD algorithm

In order to effectively detect the mechanical state of HV(High Voltage) circuit breaker and improve its operation reliability, the vibration signals during the opening/closing operation of HV circuit breaker are analyzed based on the optimized VMD(Variational Mode Decomposition) algorithm. Firstly, the optimal VMD results are obtained based on the global orthogonal coefficients by particle swarm optimization algorithm. Then the time-frequency spectrums obtained from Hilbert transformation of vibration signals are reasonably divided, accordingly the feature vector and similarity degree index of vibration signals are defined. The vibration signals of a 40.5 kV circuit breaker under normal and typical fault conditions are analyzed, and the analytical results show that the decomposition results of the proposed optimized VMD algorithm are more accurate, and the defined similarity degree index can effectively identify typical faults of circuit breaker. When the similarity degree index is greater than 0.9, the circuit breaker is in normal condition; when the similarity degree index is between 0.7 and 0.9, the circuit breaker may exist buffering mechanism defects; when the similarity degree index is smaller than 0.7, the circuit breaker may exist transmission mechanism defects. © 2018, Electric Power Automation Equipment Press. All right reserved.