提高配电网PMU测量精度的全景补偿方法

All-application-field Compensation Method for Improving Measurement Accuracy of Synchrophasor Measurement Unit for Distribution Network

配电网线路长度通常较短,且受噪声及谐波影响严重,要实现配电网的监测、控制和状态估计,亟须研制配电网同步相量测量装置(D-PMU)。高精度的测量是配电网可观可控的基石,而交流采样环节是保证D-PMU测量性能的核心。基于交流采样环节的硬件误差来源分析,提出了误差渐进减小的工程全方位应用场景补偿方法(简称全景补偿方法):①通过出厂标校,消除系统固定误差;②通过三次多项式拟合进行全量程补偿,被试装置达到应用需求精度;③通过二次多项式拟合进行温漂补偿,提升D-PMU现场运行精度。基于提出的全景补偿方法改进D-PMU,搭建了人工模拟环境,测试结果表明所提方法可有效提高D-PMU相量测量精度。

The distribution network is seriously affected by noise and harmonics and its line length is usually short,so it is necessary to develop synchrophasor measurement unit for distribution network(D-PMU)to realize the monitoring,control and state estimation of distribution network.High-precision measurement is the cornerstone for the observability and controllability of the distribution network,and the alternating current(AC)sampling module is the kernel of the measurement of D-PMU.Based on the analysis of the source of hardware error in AC sampling module,an all-application-field compensation method in the engineering with gradual error reduction is proposed to improve the measurement accuracy:(1)through factory calibration,the fixed system error is eliminated;(2)through full-range compensation based on the cubic polynomial fitting,the tested device can meet the accuracy required in application;(3)through temperature drift compensation based on the quadratic polynomial fitting,the field operation accuracy of D-PMU is improved.Using the proposed all-application-field compensation method,a D-PMU is modified for verification,and the artificial simulation environment is built.Test results show that the all-application-field compensation method can effectively improve the phasor measurement accuracy of D-PMU.