为提高输电线路故障定位精度,提出了一种基于电流分布式测量和相位比较的输电线路故障定位新方法。该定位方法基于低成本的无线传感网络和Rogowski电流互感器提供的大量电流测点,利用全相位快速Fou-rier变换(FFT)算法计算电流故障分量的相位,通过比较相邻测点的电流相位差和设定阈值的大小关系将故障点定位在相邻测点所在杆塔之间并判断出故障类型。考虑了如Rogowski电流互感器的传变特性、全相位FFT算法的抗噪性能等可能造成电流相位误差的一些主要因素影响,并对各种不同故障情况进行了仿真模拟,结果表明相角差阈值设在65°~75°间能够满足正确的故障判别要求。
In order to improve the fault location accuracy, we proposed a novel fault location scheme for transmission lines based on distributed current measurements and their phases comparison. This fault location scheme is based on lots of current measurements provided with lowcost wireless sensor networks and Rogowski coil current transformers, and all-phase FFT algorithm is used to calculate the phase angle of the fault current component. By comparing the phase angles of the fault current components with the threshold value, the fault point can be located between two towers on which the adjacent measurements are installed and the fault type can also be identified. Some of the main factors that may result in current phase angle errors are taken into account, such as the transfer characteristics of Rogowski coil current transformer, the anti-noise performance of all-phase FFT, etc. All kinds of fault cases are verified by simulation, and the results show that the correct fault identification requirements can be met when the phase angle difference threshold value is set at 65° to 75°.