【作者】 程述一；

【导师】 律方成； 谢庆；

【作者基本信息】 华北电力大学 ， 高电压与绝缘技术， 2014， 博士

【摘要】 局部放电的超声阵列检测方法是将阵列传感器与阵列信号处理技术应用于局部放电超声检测中的一种新方法。声学性能良好、维数合理的局部放电超声阵列传感器是检测技术的基础和关键。目前,关于局部放电超声阵列传感器的声学性能研究主要以定性分析为主,尚未开展系统、科学的定量研究。论文在国家自然科学基金(51307060)“局部放电超声阵列信号的提取策略研究”、河北省自然科学基金项目(2010001703)“基于超声阵列传感器的电力变压器局部放电在线定位研究”和中央高校基本科研业务费专项资金项目(09MG09)“基于超声相控阵的大型变压器局部放电定位研究”的资助下,重点开展了局部放电超声阵列传感器的声学性能评价及其稀疏设计的研究,主要内容如下：研制了适用于局部放电检测的平面方形与圆环形超声阵列传感器,并开发了相应的局部放电定位系统。首先,研究了传感器阵元的材料、中心频率、厚度以及半径等参数,并设计了单个超声阵列传感器阵元与方形、圆环形局部放电超声阵列传感器装配体；接着,制作了局部放电超声阵列传感器,并搭建了阵列传感器测试平台,对其进行了灵敏度测试,测试结果表明所研制的局部放电超声阵列传感器的频响特性与一致性良好；然后,开发了一套完整的局部放电超声阵列定位系统,包括超声阵列传感器、便携式局部放电检测系统与阵列定位软件系统,为后续研究奠定了基础。研究了一套局部放电超声阵列定位方法。分别采用FastICA(Fast Independent Component Analysis)算法、TLS(Total Least Square)算法、改进FastDOA(Fast Direction of Arrival)算法和测向线最小切球球心原理实现了局部放电超声阵列信号的去噪、聚焦、测向以及准确定位,并对其进行了仿真和实验研究,其结果验证了所提局部放电超声阵列定位方法的有效性和优越性。研究了一种局部放电超声阵列传感器的声学性能定量评价方法。针对方形和圆环形局部放电超声阵列传感器,利用惠更斯原理分别推导了其指向性函数,并定性分析了三维指向性图,论证了声学性能定量评价的必要性；然后,选择定向准确度和最大旁瓣幅值为评价指标,建立了局部放电超声阵列传感器声学性能的量化评价模型,实现了阵列传感器声学性能的定量评价；通过仿真和实验研究,得到阵列传感器的声学性能与阵列结构和阵元个数之间的变化规律,验证了所提声学性能定量评价方法的正确性。研究了一种声学性能评价与智能优化搜索相结合的局部放电超声阵列传感器稀疏设计方法。以9元、36元方形与圆环形局部放电超声阵列传感器为例,推导了考虑稀疏分布情况下,阵列传感器的指向性函数,并利用该函数,以声学性能评价值最优为目标,采用Chaotic Monkey优化算法搜索获得不同稀疏度下,阵列传感器的最优稀疏分布结构。通过仿真与实验研究发现：稀疏度一定时,最优稀疏结构下的圆环形局部放电超声阵列传感器的声学性能均优于方形阵列；阵元个数相同时,满秩圆环形阵列的声学性能最优。更多还原

【Abstract】 The detection method of partial discharge (PD) using ultrasonic array signals is a new method that applies the array sensor and array signal process technique (ASPT) to the PD detection. The ultrasonic array sensor with high quality and reasonable dimension is the key of the PD detection in electrical equipment. However, the research on the acoustic performance of PD ultrasonic array sensor is mainly just qualitative analysis, not developing the quantitive research systematically and scientifically yet.This paper is supported by National Natural Science Foundation of China(51307060)"Research on the extraction strategy of partial discharge ultrasonic array signals", Natural Science Foundation of Hebei Province in China (2010001703)"Research on the location of partial discharge in power transformer based on ultrasonic array sensors" and the Fundamental Research Funds for the Central Universities (09MG09)"Research on the location of partial discharge in transformer using ultrasonic phased array", emphatically to carry out the research on evaluating the PD ultrasonic array sensor’s acoustic performance and its sparse design. The main contents are as follows:The square and circular ultrasonic array sensors which are suitable for partial discharge detection and a complete experimental system for PD location are developed. First, we study the parameters of the array element such as its material, central frequency, thickness and the radius, and then we design the structural model of the single array element and the models of PD square and circular ultrasonic array sensors. Second, the material object is manufactured. Third, the testing platform of the array sensor is put up to proceeding the sensitivity testing. The results show that the PD ultrasonic array sensor has good frequency response characteristic and consistency. Finally, a complete experimental system of the location of partial discharge using ultrasonic array sensor is established. The system contains the ultrasonic array sensor, portable detection system of partial discharge and the software system of PD location, which is the foundation for the follow-up study.A novel effective method to locate the PD source using ultrasonic array sensor is proposed. First, the de-noising, focusing, direction-finding and accurate locating of the PD ultrasonic array signals are realized by using FastICA(Fast Independent Component Analysis^TLS(Total Least Square)^improved FastDOA(Fast Direction of Arrival) and the principal of geometrical location of bearing line’s center of minimal inscribed circle respectively. Then the simulation and experimental results verify the effectiveness and superiority of it.A quantitive evaluation method to evaluate the PD ultrasonic array sensor’s acoustic performance is proposed. First, as for square and circular PD ultrasonic array sensors, their directivity function is derived based on Huygens’ Principle. Second, the three-dimensional directivity pattern is analyzed qualitatively, which verifies the necessarity of the quantitive evaluation of the acoustic performance. Then, the directive accuracy and the maximum amplitude of side lobe are selected as indexes to establishing the quantitive evaluation model of PD ultrasonic array sensor’s acoustic performance. Finally, the variation among the array sensor’s acoustic performance, array structure and the number of array is studied by simulation and experiments, which can verify the correctness of the evaluation method proposed in this paper.A sparse design method of PD ultrasonic array sensor based on the combination of the acoustic performance evaluation and intelligent search algorithm is proposed. First, the array sensors’ directivity function considering sparse distribution are derived through the example of the square and circular PD ultrasonic array sensors with9and36array elements, through these functions, we can obtain the optimal sparse distribution structure of the array sensors under different degree of sparse with the goal of the optimal evaluation value of acoustic performance and the chaotic monkey algorithm. The simulation and experimental results show that the acoustic performance of the circular PD ultrasonic array sensor in optimal sparse structure is superior to that of square in certain sparseness, while the full-rank circular array has the best acoustic performance when the element’s number is the same.更多还原