基于分布式电流行波监测的输电线路故障精确定位装置研制

Development of Transmission Line Fault Precise Location Device Based on Distributed Current Traveling Wave Monitoring

输电线路发生故障时,及时、准确地确定故障点位置对于快速抢修及保障电力系统的安全可靠运行具有重要意义。针对传统行波故障定位装置存在定位精度低、受影响因素多的问题,研制了一种基于分布式电流行波监测的输电线路故障精确定位装置。考虑到故障行波电流具有频带宽、幅值高等特点,采用Rogowski线圈作为故障定位的基本传感单元,利用卫星授时模块的秒脉冲信号对恒温晶振时钟信号进行实时修正和IRIG-B码校正绝对时标。同时,在故障定位原理上消去行波波速、导线长度对定位精度的影响,仅利用行波波头到达定位装置的时刻计算故障点的准确位置。在实验室条件下对研制的装置开展了各项测量准确度试验和电磁兼容试验,装置在试验期间及试验后均能可靠工作,两分布式电流行波监测装置间的对时偏差小于0.1μs,故障位置的理论定位误差小于30 m、实际误差小于300 m,实现了档距范围内的高精度定位。最后,装置在某500 kV和110 kV输电线路工程上进行应用,运行期间稳定可靠。

When transmission line fault occurs,it is of great significance for rapid repair and stable operation of power system to determine the fault location timely and accurately.Aiming at the problems of low positioning accuracy and many influencing factors of the traditional traveling wave fault location device,a transmission line fault accurate location device based on distributed current traveling wave monitoring was developed.Considering that the fault traveling wave current has the characteristics of high frequency bandwidth and high amplitude,the Rogowski coil was used as the basic sensing unit for fault location,the second pulse signal of the satellite timing module was used to correct the clock signal of the constant temperature crystal oscillator in real time,and the absolute time scale was corrected by IRIG-B code.At the same time,in the principle of fault location,the influence of traveling wave speed and wire length on the location accuracy was eliminated,and the exact location of the fault point was calculated only by the moment when the traveling wave head reaches the location device.Various measurement accuracy tests and electromagnetic compatibility tests were carried out on the developed device under laboratory conditions,the device can work reliably during and after the test.The time deviation between the two distributed current traveling wave monitoring devices is less than 0.1μs,and the theoretical positioning error of fault location is less than 30 m and the actual error is less than 300 m,which realizes the high-precision positioning within the span.Finally,the device is applied in 500 kV and 110 kV transmission line projects,which is stable and reliable during operation.