基于有效值的台区电流不平衡度计算方法研究  

Study on calculation method of unbalanced factor based on RMS of fundamental current

作　　者：艾精文 张华赢 汪清 朱明星[2] 高敏 Ai Jingwen;Zhang Huaying;Wang Qing;Zhu Mingxing;Gao Min(Electric Power Research Institute of Shenzhen Power Supply Co.,Ltd.,Shenzhen 518000,Guangdong,China;School of Electrical Engineering and Automation,Anhui University,Hefei 230601,China)

机构地区：[1]深圳供电局有限公司电力科学研究院,广东深圳518000 [2]安徽大学电气工程与自动化学院,合肥230601

出　　处：《电测与仪表》2020年第11期30-36,共7页Electrical Measurement & Instrumentation

基　　金：深圳供电局有限公司科技项目(090000KK52180063)。

摘　　要：为解决在相位信息缺失条件下三相电流不平衡度准确计算的难题,提出了一种基于基波电流有效值的低压台区电流不平衡度计算方法。文章分析了基于对称分量法的电流不平衡度计算方法,以及在相位信息缺失条件下,4种常用三相电流不平衡度工程计算方法的差异性;基于对称分量法分解规律,将三相不平衡电流相量分解为两组相位对称的电流相量。在相位对称条件下,推出基于基波电流有效值的电流不平衡度计算式,确定不同工况下两组电流不平衡度的主从关系;结合低压台区负荷电流的不平衡特性,分析了计算方法在低压台区三相电流不平衡度计算中的适用性及差异性,并对低压台区运行数据进行实测验证。与4种常用工程计算方法相比,所提方法与对称分量法计算结果更加接近,且基本一致。In order to solve the problem that it is difficult to accurately calculate the three-phase current unbalanced factor when missing the phase information,a calculation method of unbalanced factor based on the RMS of fundamental current was proposed in this paper.Firstly,this paper analyzes the calculation method of three-phase current unbalanced factor based on symmetrical component method,and the difference of four commonly used engineering calculation methods of three-phase current unbalanced factor when missing the phase information;Secondly,based on the decomposition law of symmetrical component method,the three-phase unbalanced current was decomposed into two groups of current phasors which is phase symmetrical,the calculation formula of current unbalanced factor based on the effective value of fundamental current is derived when the phase symmetry,and then,the master-slave relationship is determined between two groups of current unbalanced factor under different working conditions.Finally,the applicability and difference of the calculation method in the calculation of three-phase current unbalanced factor are analyzed based on the unbalanced characteristics of load current in the low-voltage district,and the operation data in the low-voltage district are measured and verified,Compared with the four commonly used engineering calculation methods,the calculation results of the proposed method and the symmetrical component method are more close and basically consistent.

关 键 词：低压台区 电能质量 三相不平衡 不平衡度 

分 类 号：TM711[电气工程—电力系统及自动化]