Research On Partial Discharge Diagnosis Of Switchgear Based On TEV And Ultrasonic Joint Detection

In recent years,with the rapid development of power systems,the number of switchboards running in the network is increasing.But at the same time switchgear break down frequently,causing great losses for the economy and society.So the switchgear for non-power detection has far-reaching significance.TEV method and ultrasonic wave detection technology and its characteristics make it suitable for high voltage switchgear partial discharge detection.The essay mainly focuses on the principle and detection methods of the two methods above in further study.In the deep diagnosis of the switchgear,whether the measured signal is a partial discharge signal is one of its important work.Through extracting features of partial discharge signal and establishing partial discharge typical signal feature library,extract and recognize the original signal of TEV and ultrasonic with the establishment of algorithms.In this paper,I further study typical defects of TEV,ultrasonic defects and the pattern recognition,analyzing several typical defects of partial discharge characteristics and pattern recognition methods in detail and researching on the spectral characteristics of typical defects partial discharge,time domain analysis and separation technology-level applications of Switching cabinet multi-source partial discharge signal in depth.In order to study the partial discharge characteristics of the switchgear,the typical partial discharge model of the switchgear is analyzed.It shows that there are many problems in the partial discharge detection of switchgear based on TEV method and the discharge characteristics of different discharge are different.The insulation state the same discharge amplitude and repetition rate stands for in different discharge types,may also be different.Therefore,it is necessary to carry out the discharge pattern recognition of the signal.The result shows that the mode identification of single source discharge can be realized by using the discharge phase characteristic.In this paper,signal separation and clustering technology can not only distinguish different discharge types,but also has the potential to identify and separate the interference pulse.Both the TEV algorithm and the ultrasonic algorithm are based on continuous signal analysis.Some of the algorithms can be generalized,but the related characteristic parameters are different.The pattern recognition method based on the ultrasonic method is a pattern recognition method for general conventional signals,which can be applied to pattern recognition of pulse current,UHF and TEV signals.Finally,a method of joint detection of switchgear is proposed.Through the innovation of routing inspection pattern,thetour inspection would be improved.The insulation state evaluation system will be set up by analyzing operation conditions of Switchgear.Tests can be carried on combing multi-technology.Total data can be analyzed comprehensively.According to the comprehensive evaluation results,optimize the maintenance strategy.In-depth evaluation would be carried on about the switchboard internal office of the switchboard accurately and efficiently.The feasibility and effectiveness of the joint detection and diagnosis of the switchgear would by proved combining the actual situation.