Study On The Application Of RD-MUSIC Algorithm In The PD Ultrasonic Array Detection

When the partial discharge(PD)occurs in the power transformer,the location of the PD has a great influence on the evaluation of the insulation condition of the power transformer.The direction finding accuracy of the PD detection based on the MUSIC algorithm meets the actual requirements of the project.However,due to the MUSIC algorithm,using a two-dimensional spatial spectrum peak search,the contour map and the peak figure cann't be visually seen the PD source direction of arrival(DOA)estimation from the figures,and it has high computational complexity,poor accuracy,remains to be further improved.This paper is emphatically to carry out the research on the application of reduced dimension MUSIC(RD-MUSIC)algorithm in the PD ultrasonic array detection.The main contents are as follows:(1)Direction finding algorithm of the PD ultrasonic array based on the RD-MUSIC is proposed.The algorithm that made two dimensional parallel search method to be decomposed into the one-dimensional sequence search of azimuth and elevation angle.A simulation model of the PD signal and the ultrasonic array sensor was established.And the performance and complexity of the RD-MUSIC algorithm were studied.Moreover,the simulations of the single source and double sources were carried out based on the RD-MUSIC,and compared with the FastDOA algorithm and the Root-MUSIC algorithm.The results show that the RD-MUSIC algorithm has low computational complexity,fast calculation speed,high direction accuracy,and the resolution are good,besides,the star spectrum can estimate the azimuth information about the signal source directely.Finally,the simulations verify the feasibility of the algorithm.(2)The simulation of the sparse array sensor based on the RD-MUSIC algorithm was carried out.Using the RD-MUSIC algorithm,the simulations of single source and double sources with 4 sparse array sensors were studied.The simulation results show that the RD-MUSIC algorithm with better direction finding performance can make up the deficiency of the direction finding performance of the array structure itself,and reduce the influence of the array structure on the direction finding error,and thus improve the positioning accuracy.(3)The experimental platform was improved,the RD-MUSIC algorithm was used to deal with the measured PD ultrasonic array signal,which was collected with the full array and sparse array respectively.Moreover,the experimental results verify that the full array and sparse array based on RD-MUSIC method can be used to realize the estimation DOA for single source and double PD sources.It can realize the accurate direction finding of the sources,improve the positioning accuracy,and provide the important guidance information in the practical application.