降维MUSIC算法在局放超声阵列检测中的应用研究

发布时间：2018-06-04 16:13

本文选题：局部放电 + 降维MUSIC　；参考：《华北电力大学》2017年硕士论文

【摘要】：电力变压器内部发生局部放电时,其发生位置对电力变压器绝缘状况的评估影响很大。现有的基于MUSIC的局放超声检测方法,其测向精度在一定程度上,满足工程实际的要求。但是,由于MUSIC算法,采用的是二维空间谱峰搜索,其等高线图以及谱峰图不能直观的从图中看出局放源的波达方向(DOA)估计量,且计算复杂性较高,测向精度较差,还有待进一步提高。据此,论文重点开展了降维MUSIC算法在局放超声阵列检测中的应用研究。主要内容如下:(1)提出了一种降维MUSIC的局放超声阵列的测向方法。该方法将局放超声阵列信号的波达方向(方位角和俯仰角)的谱峰空间二维并行搜索方式,降维分解为方位角和俯仰角的一维顺序搜索方式。建立了局放信号和超声阵列传感器的仿真模型,研究了降维MUSIC算法的性能以及复杂度,开展了基于降维MUSIC的局放超声阵列对单局放源及双局放源的仿真研究,并与基于Fast DOA算法和Root-MUSIC算法的局放超声阵列对单局放源仿真结果进行了对比分析。结果表明:该方法计算复杂性较低,计算速度快,测向精度高,分辨性能好,并且其测向星谱图可直观估计出信号源的方位信息,验证了该测向方法对局放源DOA估计的可行性。(2)开展了基于降维MUSIC的局放超声稀疏阵列传感器对局放源进行定位的仿真研究。采用降维MUSIC算法,利用4种稀疏阵列传感器对单局放源及双局放源进行定位仿真研究。仿真结果表明:测向性能较好的降维MUSIC算法,可以弥补阵列结构本身的测向性能的不足,降低了阵列结构对测向误差的影响,进而提高定位准确度。(3)完善了实验平台,开展了将降维MUSIC算法应用于处理满阵及稀疏阵列分别采集的模拟实验中实测的局放超声阵列信号的实验研究。实验结果验证了基于降维MUSIC测向方法的满阵及稀疏阵列对单局放源及双局放源均可实现DOA的估计,并且其测向精度较高,进而提高了下一步定位的准确度,为实际应用提供重要的指导信息。
[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.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM855

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