用于变压器中局部放电定位的十字形超声阵列传感器研究  

Study of Cross-shaped Ultrasonic Array Senor Applied to Partial Discharge Location in Transformers

作　　者：辛晓虎[1] 李继胜[1] 纪海英[2] 罗勇芬[1] 李彦明[1] 

机构地区：[1]西安交通大学电气工程学院,陕西省西安市710049 [2]唐山供电公司,河北省唐山市063000

出　　处：《中国电机工程学报》2013年第21期154-162,205,共9页Proceedings of the CSEE

基　　金：国家自然科学基金项目(50877064;50977075)~~

摘　　要：局部放电是电力变压器绝缘劣化的主要原因,研究局部放电定位对提高电网的安全运行很有帮助。该文研制了一种用于电力变压器局部放电定位的复合传感器,并针对该传感器进行了定位仿真和实验。复合传感器由共形的13阵元十字形超声波传感器阵列和22阵元的超高频传感器阵列组成。应用高阶累积量处理技术对十字形超声阵列进行虚拟扩展,扩展后阵列具有61个阵元的阵列性能,提高了超声阵列的孔径和方向性锐度,这极大减少了后续硬件电路和成本。利用扩展超声阵列配合超高频阵列来仿真局部放电定位,结果表明扩展阵列具有很好的定位效果。在噪声背景下与多重信号分类(multiple signal classification,MUSIC)方法作了比较,结果表明高阶累积量处理技术能更好地抑制各种高斯色噪声的干扰。基于该十字形超声波阵列传感器进行了局部放电定位实验,结果表明扩展后的十字形超声阵列能精确地定位局部放电,定位的相对误差小于5%。对较少数目阵元的阵列实施虚拟扩展技术,为阵列技术在电力设备上的实用化提供了可能性。Partial discharge（PD） is the main reason for the deterioration of the power transformer insulation.Partial discharge location is helpful to improve the safe operation of power grid.A combined sensor is designed to locate PD in transformer,and based on the sensor PD location simulation and experiments are made in this paper.The combined sensor includes a cross-shaped ultrasonic phased array of 13 array elements and a conformal 2 2 ultra-high-frequencies（UHF） electromagnetic array.The ultrasonic array can achieve the effect of 61 virtual array elements with high-order cumulants processing technology.It can greatly improve the aperture and direction sharpness of the array and reduce the cost of followed-up hardware.The expanded array and the UHF array were used to simulate to locate PD,the results are precise.And the noise suppression effect is compared with the multiple signal classification（MUSIC） method.Simulation results show that virtual expanding array has strong ability to suppress various colored noise interference.PD location experiments are made based the cross-shaped ultrasonic phased array,the results show that the locations are precise and its relative error is less than 5%.Virtual expanding to array with fewer number elements provides the possibility for the practical application of array technology in power equipment.

关 键 词：局部放电 十字形超声波阵列传感器 高阶累积量 噪声抑制 虚拟阵列扩展 

分 类 号：TM855[电气工程—高电压与绝缘技术]