Pulse Current Signal Detection And Signal Processing Of Cable Partial Discharge

In recent years,with the rapid development of power industry,cable has brought great convenience to people's life and production.But once the cable fails,it will bring serious economic losses.So through the partial discharge signals detection and signal processing to find the cable fault have been paid more and more attention.Analysising the partial discharge signals based on the pulse current method when power cable occurs fault to collect and denoising partial discharge signal.Finally,design the peak pulse signal generator for the measurement of the cable fault.Firstly,setting up the model of the power cable in the Matlab.And the PD signals of different frequencies are added to this model to analyze the propagation characteristics of PD signals in the cable.Secondly,analysising the advantages of the coil transformer compared with the traditional transformer.Reseraching the structure and principle of Rogowski coil and describing the frequency characteristics of Rogowski coil,designing the coil parameters.The model of the Rogowski coil transformer was builded in the Simulink and observing the influence of parameters of mutual inductor on signals.Ultimately selecting the appropriate coil parameters to complete the design of Rogowski coil transformer.Thirdly,Using wavelet threshold denoising method to deal with the collected PD signals.The hard threshold and soft threshold has been widely used,but there is a potential disadvantage.Therefore,a new threshold denoising function is applied to the PD signal denoising,which calculating simply,the threshold of the signal can be changed according to different noises.Using new threshold,soft threshold and hard threshold for signal denoising simulation,observing the different denoising effect.Finally,according to the measurement requirements,the design of the main circuit of the spike voltage geneartor is required for the detection of the cable.The inductive energy storage parallel type of main circuit is selected,the parameters of each circuit module of the main circuit are analyzed.Finally,the appropriate circuit parameters are selected to meet the required measurement and conducting the simulation.