低压配电网用户相位识别方法研究  

Research on phase identification method of low-voltage distribution network users

作　　者：李方硕 刘丽娜 申杰 王韬 熊思宇[2] LI Fangshuo;LIU Li’na;SHEN Jie;WANG Tao;XIONG Siyu(State Grid Sichuan Metrology Center,Chengdu 610045,China;School of Electrical Engineering,Southwest Jiaotong University,Chengdu 611756,China)

机构地区：[1]国家电网四川省计量中心,四川成都610045 [2]西南交通大学电气工程学院,四川成都611756

出　　处：《中国测试》2024年第3期52-61,共10页China Measurement & Test

基　　金：国家自然科学基金面上项目(51777173);国网四川省电力公司科技项目(52199720005Z)。

摘　　要：配电网由于负荷不均衡,会产生三相不平衡现象。该文提出一种用户相位识别和三相电流相位不平衡检测方法。该方法能够有效辨识同一台区下的用户相位,为用电信息采集和台区治理提供数据基础。考虑到电力信号的动态特性,首先借助泰勒级数来近似表示信号的时变相量;其次联立窗内每个数据点对应的关系方程,并通过最小二乘法求解出泰勒系数,得到精准的相量测量值,然后对用户与变压器处的相位分别进行相移与相位补偿;最后通过比较两者的相位差与所设阈值之间的关系实现用户相位归属关系识别。完成用户的相位识别之后,通过变压器低压侧三相电流的相位差值可判断配电网三相电流相位的不平衡情况,为配电网三相不平衡时的换相、电网重构等措施提供监测分析数据。仿真结果表明,文章所提方法在频率偏移条件下,可以实现台区用户相位的准确识别,而在谐波干扰条件下,识别成功率均高于90%。相比于传统的用户与变压器电压相关性分析方法,所提方法识别精度和鲁棒性均得到较大提升。Due to the unbalanced load in the distribution network,three-phase unbalance will occur.This paper proposes a user phase identification and three-phase current phase imbalance detection method.This method can effectively identify the phases of users in the same station area,and provide a data basis for electricity consumption information collection and station area management.Considering the dynamic characteristics of the power signal,firstly,the Taylor series is used to approximate the time-varying phasor of the signal.Secondly,the relationship equation corresponding to each data point in the window is simultaneously established,and the Taylor coefficient is solved by the least square method to obtain an accurate phase.Then,phase shift and phase compensation are performed on the phases at the user and the transformer,respectively.Finally,by comparing the relationship between the phase difference and the threshold value,the user phase attribution relationship is recognized.After the phase identification of the user,the phase difference of the threephase current on the low-voltage side of the transformer can be used to judge the unbalance of the three-phase current phase of the distribution network,and provide monitoring and analysis data for the measures of commutation and network reconstruction when the three-phase unbalance of the distribution network occurs.The simulation results show that the method proposed in this paper can accurately identify the phase of users in the station area under the condition of frequency offset,and the identification success rate is higher than 90%under the condition of harmonic interference.Compared with the traditional user-transformer voltage correlation analysis method,the recognition accuracy and robustness of the proposed method have been greatly improved.

关 键 词：泰勒级数 相位识别 相量测量 相位补偿 

分 类 号：TM933[电气工程—电力电子与电力传动] TB9[一般工业技术—计量学]