Mechanical parameters on-line monitoring method for high voltage vacuum circuit breaker using fiber optic displacement sensors

Mechanical parameters are regarded as important content of high voltage vacuum circuit breaker's (HV-VCB) condition monitoring, and the location of closing and separating moment is the premise and key for these parameters' calculation. An on-line monitoring system based on FPGA+ARM+SBC for HV-VCB is designed and developed with various functions. On the basis of which, a new singular point detection method based on ensemble empirical mode decomposition (EEMD) is proposed and applied to mechanical parameters' calculation. Displacement signals are collected by on-line monitoring system firstly. Then, EEMD is adopted to decompose displacement signal into several intrinsic mode functions (IMF) which can eliminate interference. Afterwards, singular point is extracted which is regarded as the closing moment. Finally, mechanical parameters can be calculated. This method has been applied to analyze and process displacement signals of HV-VCB which type is VMB5–12. The calculation results of the experiments are much more precise. Satisfactory performance of on-line monitoring system and calculation method for mechanical parameters are certified by experimental results.