Research On Insulation Fault Diagnosis And Anti-interference Algorithm Of 10kV Ring Network Cabinet Based On UHF

With the continuous development of the city,the scale of the power grid continues to expand,and users have higher and higher requirements for power quality.As an important equipment for connecting users to the power grid,the 10 k V ring main unit is used to detect the insulation status during operation to ensure the safety and stability of the power system.One of the important means of reliable operation.Generally speaking,partial discharge detection is the important way to determine the insulation status of equipment.Among the many partial discharge detection methods,the ultra-high frequency detection method has become one of the most popular detection methods due to its excellent anti-interference ability and high sensitivity.However,this method also has limitation.This kind of interference cannot be effectively identified and filtered,so it is necessary to design a corresponding anti-interference algorithm to filter the interference mixed in it.This article adopts the method of simulation experiment,introduces the interference source,carries on the simulation to the tip discharge and the creeping discharge.First,by comparing the parameters of the five antennas with the discharge waveforms collected under actual working conditions,the UHF pulse antenna is finally selected as the experimental antenna.The discharge model was simulated before the experiment,after verifying the rationality of the design of the discharge model,a complete experimental platform was built to conduct simulation experiments and obtain experimental data.After the experimental platform is built,in order to cooperate with the high-speed acquisition system of the lower computer based on the FPGA chip for data storage,the upper computer part needs to cooperate to save the experiment time and cost to the greatest extent.This article compares the data receiving program written in C# and Python language.Finally,choose C# as the programming language and design the UI interface to complete the high-speed data reception,high-speed data collection,packet loss search and packet loss rate calculation,file name storage and other functions.Due to the introduction of interference sources,it is necessary to filter the collected discharge signals.By analyzing the collected partial discharge waveforms,the characteristics of periodic narrowband interference,square wave interference,zero-crossing interference and white noise in the time domain and frequency domain are studied.,Design targeted anti-interference methods,such as cross-correlation function method,waveform morphology method,phase filter method,FFT,EEMD,wavelet soft threshold noise reduction,etc.and integrate these algorithms to form a cross-correlation based on time domain characteristics Function and waveform shape parameter anti-jamming algorithm and FFT-EEMD-wavelet soft-threshold anti-jamming algorithm based on frequency domain characteristics,using experimental data of different voltage levels to verify the two algorithms,and the filtering effect of the two anti-jamming algorithms By comparison,it is found that the two algorithms have their own advantages and disadvantages.Among them,the maximum cross-correlation function anti-interference algorithm has advantages in calculation time and discharge signal feature preservation,and the FFT-EEMD-wavelet soft threshold anti-interference algorithm is used in partial discharge signal extraction.It has more advantages.After comprehensive comparison,it is found that the maximum cross-correlation function method is more sui Tab.for rapid judgment of partial discharge on site.