基于超高频电磁波的变电站局部放电空间定位

Partial Discharge Location Based on Radio Frequency Antenna Array in Substation

局部放电的测量和诊断已成为评估高压电力设备运行状态的重要方法之一。但目前的局部放电监测主要以单个设备监测为主,测试仪器程序多,成本高,维护工程大。可利用4个天线组成天线阵列接收超高频(UHF)电磁波,并定义三维坐标系对变电站范围内的放电源进行全站的局放定位。重点研究了基于能量积累法计算信号起始时刻和基于信号时延序列实现放电源准确定位算法的原理,并给出了求解基于时差的以局放源位置为未知数的非线性方程组的Newton算法和网络搜索法。实验室测试和现场测试验证了基于射频天线阵列实现变电站范围内局部放电定位的有效性,提出的定位算法可以自适应求解基于时差序列的非线性方程组,既保证了求解的速度,又能解决方程的收敛问题,满足变电站全站局部放电定位准确度的要求。

The measurement and diagnosis of partial discharge （PD） is accepted as the most valuable means for assessing the quality of high voltage （HV） power apparatus and its running status. However, the methods for monitoring current partial discharge are mainly based on devices, which require multi-process, high cost, and large maintenance engineering. We proposed to use four antennas array to receive ultra high frequency （UHF） signal, and defined a 3-D coordinate system to locate PD source in the field of the substation. We focused on the principles of calculating signal starting time by energy accumulation method as well as the location algorithm based on time difference, and gave a Newton algorithm and stepped-net search methods to solve the nonlinear equations. Finally, we proved the efficiency of the system by lab and site test. The algorithm can ensure the solving speed, and solve the problem of convergence, thus, it can satisfy the requirments of the accuracy of PD location in the entire substation.