| With the development of society and the progress of the times,people's work and life are increasingly inseparable from the power.This requires the power system to be reliable and stable.However,in China's power grid transformer accident,the proportion of partial discharge accidents due to insulation aging is as high as nearly 70%.This serious phenomenon has caused people to attach great importance to the phenomenon of power grid partial discharge.It is of practical significance to thoroughly study the principle of partial discharge of equipment,timely monitor the partial discharge signal of the equipment,increase the denoising technology of mixed partial discharge signal with noise,and extract the discharge signal,in order to maintain and ensure the stable power supply of the transmission network.The principle of single air gap partial discharge is introduced in this thesis.Considering that in the actual signal detection,the collected discharge signal usually contains noise interference.Therefore,for the problem of signal denoising,this thesis uses the Matlab simulation software to use the improved wavelet threshold function to denoise the noisy signal.Then use the firl function and filter function in Matlab software to simulate the FIR low-pass filter and filter the local high-frequency signal.By simulating the partial discharge in Simulink,the number of discharge in the air gap inc-reases with the increase of the added AC voltage,and the number of the corresponding discha-rge pulse current is also increasing.Wavelet denoising and lowpass filtering denoising,by ana-lyzing the denoised data,verify the excellent perfonnance of the denoising method.Because of its limitation in application,single denoising technology is not suitable for analyzing and pro-cessing most of the discharge situations.Therefore,in the denoising of noisy signals,a variety of denoising equipment and denoising technology can be combined to make the extracted si-gnal better denoising effect. |
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