本文選題：局部放電 + 降維MUSIC　； 參考：《華北電力大學(xué)》2017年碩士論文

【摘要】：電力變壓器內(nèi)部發(fā)生局部放電時,其發(fā)生位置對電力變壓器絕緣狀況的評估影響很大。現(xiàn)有的基于MUSIC的局放超聲檢測方法,其測向精度在一定程度上,滿足工程實際的要求。但是,由于MUSIC算法,采用的是二維空間譜峰搜索,其等高線圖以及譜峰圖不能直觀的從圖中看出局放源的波達方向(DOA)估計量,且計算復(fù)雜性較高,測向精度較差,還有待進一步提高。據(jù)此,論文重點開展了降維MUSIC算法在局放超聲陣列檢測中的應(yīng)用研究。主要內(nèi)容如下:(1)提出了一種降維MUSIC的局放超聲陣列的測向方法。該方法將局放超聲陣列信號的波達方向(方位角和俯仰角)的譜峰空間二維并行搜索方式,降維分解為方位角和俯仰角的一維順序搜索方式。建立了局放信號和超聲陣列傳感器的仿真模型,研究了降維MUSIC算法的性能以及復(fù)雜度,開展了基于降維MUSIC的局放超聲陣列對單局放源及雙局放源的仿真研究,并與基于Fast DOA算法和Root-MUSIC算法的局放超聲陣列對單局放源仿真結(jié)果進行了對比分析。結(jié)果表明:該方法計算復(fù)雜性較低,計算速度快,測向精度高,分辨性能好,并且其測向星譜圖可直觀估計出信號源的方位信息,驗證了該測向方法對局放源DOA估計的可行性。(2)開展了基于降維MUSIC的局放超聲稀疏陣列傳感器對局放源進行定位的仿真研究。采用降維MUSIC算法,利用4種稀疏陣列傳感器對單局放源及雙局放源進行定位仿真研究。仿真結(jié)果表明:測向性能較好的降維MUSIC算法,可以彌補陣列結(jié)構(gòu)本身的測向性能的不足,降低了陣列結(jié)構(gòu)對測向誤差的影響,進而提高定位準(zhǔn)確度。(3)完善了實驗平臺,開展了將降維MUSIC算法應(yīng)用于處理滿陣及稀疏陣列分別采集的模擬實驗中實測的局放超聲陣列信號的實驗研究。實驗結(jié)果驗證了基于降維MUSIC測向方法的滿陣及稀疏陣列對單局放源及雙局放源均可實現(xiàn)DOA的估計,并且其測向精度較高,進而提高了下一步定位的準(zhǔn)確度,為實際應(yīng)用提供重要的指導(dǎo)信息。
[Abstract]:When partial discharge occurs in power transformer, the location of partial discharge has a great influence on the evaluation of power transformer insulation. The existing partial discharge ultrasonic detection method based on MUSIC has a certain degree of accuracy and meets the requirements of engineering practice. However, due to the MUSIC algorithm, two-dimensional spatial spectral peak search is used. The contour and spectral peak maps can not directly see the DOA (DOA) estimator of the partial discharge source from the graph, and the computational complexity is high, and the direction finding accuracy is poor. There is still room for further improvement. Therefore, this paper focuses on the application of reduced dimension MUSIC algorithm in PD ultrasonic array detection. The main contents of this paper are as follows: 1) A direction-finding method for partial discharge ultrasound array with reduced dimension MUSIC is proposed. In this method, the direction of arrival (azimuth and pitch angle) of partial discharge ultrasonic array signal is searched in two dimensional parallel mode, and the dimension reduction is decomposed into one dimensional sequential search method of azimuth and pitch angle. The simulation models of partial discharge signal and ultrasonic array sensor are established, the performance and complexity of dimensionality reduction MUSIC algorithm are studied, and the simulation research of partial discharge ultrasonic array based on reduced dimension MUSIC to single local discharge source and dual local discharge source is carried out. The simulation results of single PD source are compared and analyzed with the partial discharge ultrasonic array based on Fast DOA algorithm and Root-MUSIC algorithm. The results show that the method has the advantages of low computational complexity, high speed, high precision and good resolution, and the azimuth information of the signal source can be directly estimated by its direction-finding star spectrum. The feasibility of this direction finding method for partial discharge source DOA estimation is verified. (2) Simulation study of partial discharge ultrasonic sparse array sensor based on reduced dimension MUSIC is carried out to locate partial discharge source. Using reduced dimension MUSIC algorithm, four kinds of sparse array sensors are used to simulate the location of single local discharge source and double partial discharge source. The simulation results show that the dimensionality reduction MUSIC algorithm with good direction-finding performance can make up for the deficiency of the direction-finding performance of the array structure itself, reduce the influence of the array structure on the direction-finding error, and then improve the positioning accuracy. In this paper, the reduced dimension MUSIC algorithm is applied to deal with the measured partial discharge ultrasonic array signals in the simulation experiment of full array and sparse array. The experimental results show that the full array and sparse array based on reduced dimension MUSIC direction finding method can realize the DOA estimation of single partial discharge source and double partial discharge source, and the accuracy of direction finding is high, and the accuracy of next step location is improved. It provides important guiding information for practical application.
【學(xué)位授予單位】：華北電力大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TM855

【參考文獻】

相關(guān)期刊論文 前10條

1 劉丹;孔靜;謝慶;陶s，

本文編號：1978009