Line Monitoring And Fault Diagnosis Of Electrical Equipment

Based on the conception of device maintenance of Electrical Power System , this paper d iscuss the p ossibility and necessity o f s tatus monitoring and fault d iagnosis technology and take the HV (high voltage) circuit breaker as the example .The HV circuit breaker is one of the major critical components , which controls and protects power network,so its reliability service is very important. At home , the HV circuit breakers are overhauled regularly by routine operation now. This way is eyeless which usually brings the new fault to system and reduce the reliability and stability. So it is necessary to develop the on-line monitoring and fault diagnosis for the real-time state of he HV circuit breaker.Because the most faults of circuit breakers root from mechanism, the diagnosis technique for mechanical faults of the circuit breakers if of far reaching importance. The mechanism vibration signal contains plentiful state information of the equipment as an abundant information carrier . With the progress of the technology of sensor , signal processing and computer, it is impossible to diagnose the mechanism state of the circuit breaker on the vibration signal. On this paper , two methods of the vibration signal processing have been put forward: the develop of signal trend and the analysis of the maximum module based on the wavelet transform.The first method : Capture the signal s low frequency component according to the wavelet transform which can reflect the signal's developing trend. Then it can estimate the status of HV circuit breaker according to compare the normal condition's waveform with the fault condition's waveform.The second method: Process the mechanism vibration signal on the theory of wavelet singularity detection. When the signal occur the singularity ,the coefficient's maximum module can appear. It can confirm the time when the fault occur. At the same time ,the module can be considered the characteristic parameters for the fault diagnosis.Finally, the paper introduces the realization of the online status monitoring andfault diagnosis system which includes the hardware and software. For the hardware, we mainly discuss the feature and parameter of BH5116. For the software, the system is made of Visual C++6.0, Matlab6.5, which can obtain the function about data acquisition, data storage , data communication. In the processing ,VC can directly call Matlab program to carry out the data process and data analysis.