Research On Integrated Monitoring And Control System For High-Voltage Circuit Breaker

Routine maintenance of high-voltage(HV)circuit breaker is very time consuming and resource hungry. The traditional scheduled maintenance or Time Based Maintenance (TBM) has some serious defects, such as sub-maintenance, over-maintenance and the faults caused by the maintenance itself. Condition Based Maintenance (CBM), being based upon condition monitoring, is the most advanced maintenance program nowadays. The evolvement from TBM to CBM is imperative and exciting. However, the research on CBM is yet in the beginning in China. The condition monitoring systems on site are usually simple, function insufficient or short of integration. Giving emphasis to signal processing methods, this paper puts forward the idea of integrated monitoring system for HV circuit breaker and thus develops an archetypal system. The main contents are given as below: Firstly, the signification to develop CBM is discussed. Aiming at the existing problems in the on site monitoring system for circuit breaker, the basic principles and general structure and function of the integrated monitoring system are established and discussed. Secondly, the possibility and efficiency of applying the spectrum analysis usually used in vibration testing for rotating machine to operation vibration of HV circuit breaker is discussed, The paper goes deeply into this new method and idea, especially the zoom spectrum algorithm. By comparing normal FFT, Zoom-FFT (ZFFT) and Chip-z Transform (CZT) on principle, arithmetic, characteristic and amount of calculation, CZT is proved superior and thus selected. Thirdly, on account of the poor reality that the full fault patterns of HV circuit breaker is difficult to establish due to lack of raw data, an alternate method, namely Similarity Analysis (SA), is proposed. The basic idea of SA is comparing the data of condition to be assessed with the data of working condition. The application of SA in operation vibration analysis and trip coil profile analysis of HV circuit breaker is studied. Some other signal processing methods, such as Welch Method, digital filter and parameter fit are also discussed. Finally, the background software of the integrated monitoring system is developed based on a typical 110kV/10kV substation.