基于最小二乘法的变电站故障录波测距系统设计

Design of Substation Fault Recording and Ranging SystemBased on Least Squares Method

当前,变电站故障区域受录波器性能的影响,阻抗值获取难度较大,导致故障区域测距效率较低。为提高变电站故障区域的测距效率、确保变电站的供电稳定,设计了基于最小二乘法的变电站故障录波测距系统。在系统硬件部分,采用分布式的电力故障录波器装置,收集变电站电力数据,利用以太网后台机完成数据传输。在系统软件部分,凭借最小二乘法计算模拟量通道的变比参数,校正电力录波装置通道间的相位误差,以提高录波器模拟量的测量精度。通过故障相电流差与相电压差获得阻抗值结果,计算出变电站故障录波的准确距离。试验结果表明:所设计系统的步角误差与测距误差均较小,故障录波测距误差降到了1%以内。该系统可以有效完成变电站故障点的精准定位,具有较高的参考价值。

Currently, the fault area of a substation is affected by the performance of the recorder, and it is difficult to obtain the impedance value, which leads to the low ranging efficiency of the fault area.To improve the ranging efficiency of the substation fault area and ensure the power supply stability of the substation, a substation fault recording and ranging system based on least squares method is designed.In the hardware part of the system, a distributed power fault recorder device is used to collect power data from the substation, and the Ethernet backend machine is used to complete the data transmission.In the software part of the system, the ratio parameter of the analog channel is calculated by the least squares method, and the phase error between the channels of the power recording device is corrected, so as to improve the measurement accuracy of the analog quantity of the recorder.The impedance value results are obtained through the fault phase current difference and phase voltage difference, and the accurate distance of substation fault recording is calculated.The test results show that the step angle error and ranging error of the designed system are both small, and the ranging error of fault recording is reduced to within 1%.The system can effectively complete the accurate localization of substation fault points and has high reference value.