The Location Method Of Cable Partial Discharge Signals Base On Correlation Analysis

The coverage rate of the power cable is getting higher in the city,and the safe operationof the power grid is closely related with the insulation state of the power cable. Partialdischarge is an important indicator to reflect the cable insulation condition. Therefore, how tofind the location of partial discharge that is great significance to carry out the safety work ofpower grid.The generation of partial discharge signal is connected with the electric field distributionof cable and the cable construction, and it is vulnerable to background noise.Study PDsignal generation mechanism in power cable and the detection principle,propose the targeteddenoising method. By laboratory simulations,we can find the band-pass filter and waveletfilter better.This paper analyzes the characteristics of the partial discharge signal,selects thecalculation method of the characterization of PD signals in the frequency domain and timedomain, and studys the transmission characteristics of the PD signal in the cable.Due to theattenuation and reflection phenomenon,waveform with the transmission distance increasingamplitude is smaller width is larger.This paper compares the cable PD detection methods,comprehensive analyses thecurrent commonly used methods of fault location.For the deficiencies of these methods, suchas the positioning accuracy is not high,vulnerable to the environmental factors, not locate along-distance cable. Proposing positioning method based on correlation analysis for the cablePD signals, realized waveform identification on the cable partial discharge. Find the pulse ofthe reflection points corresponding to the original pulse,and calculate the cable PD locationquickly.Experimental data and case analysis shows that this method have a high positioningaccuracy,which can detect long-distance cable effectively.The correlation is an important signal analysis method. There’s significant correlationbetween PD signal in before and after unit time, which is similarity reflects in waveform, theuse of the segment before and after the PD signal acquisition to determine the location of thefault. Collected the PD signal before and after paragraph to determine the location of thefault.The main work of the author is to complete the location algorithm based on correlation, and the involved theoretical research. Finally, together with members of the softwaredevelopment team,fault location method based on correlation analysis applied to the softwaremodule, to achieve the precise location of the cable.