改进的配电网对地参数谐振测量方法  

An improved resonance measurement method of grounded parameters for distribution networks

作　　者：曾祥君[1] 刘玉玲 喻锟[1] ZENG Xiangjun;LIU Yuling;YU Kun(Hunan Province Key Laboratory of Smart Grids Operation and Control,Changsha University of Science and Technology,Changsha 410114,China)

机构地区：[1]长沙理工大学智能电网运行与控制湖南省重点实验室,湖南长沙410114

出　　处：《电力科学与技术学报》2020年第3期3-11,共9页Journal of Electric Power Science And Technology

基　　金：国家自然科学基金重点项目(51737002);国网湖南省电力有限公司科技项目(5216A01700AH)。

摘　　要：在配电网中性点经消弧线圈串联阻尼电阻接地方式下现有对地参数测量方法测量误差较大,因此,提出一种改进的配电网对地参数谐振测量方法。该文分析消弧线圈串联阻尼电阻方式下现有对地参数测量方法的局限性,并通过分别构建消弧线圈串联、并联阻尼电阻2种接地方式下的谐振测量等效回路,推导了2种接地方式下配电网对地电容和对地泄漏电导数学表达式。通过在中性点接入变频恒流信号源,向配电网注入特征电流信号并实时测量零序电压互感器开口三角形处特征电压信号,可测得系统谐振频率;进而依据对地参数表达式实现配电网对地参数的快速、准确测量。PSCAD/EMTDC仿真分析和模拟实验验证了所提方法的正确性,仿真分析与实验结果均表明该方法测量对地参数精度高、适用范围广。In the distribution power system with its neutral point grounded by an arc suppression coil connected with the damping resistance in series,the existing method for the grounded parameter measurement is not accurate e nough.Therefore,an improved resonance measurement method of grounded parameters is proposed for distribution power systems.In this paper,the influence from the damping resistance on the arc-suppression coil compensation is analyzed.And then,the equivalent circuit of resonance measurement is constructed respectively for two grounding modes whose arc suppression coils connect a damping resistance in series and parallel.In addition,the mathematical expressions of the distribution power system's grounded capacitance and grounded leakage conductance are derived r espectively.A current signal with characteristic frequency is directly injected into the distribution network through the neutral point connected to the constant current signal source with the variable frequency,and the characteristic voltage signal is measured through the triangular side of zero-sequence voltage transformer.In terms of the grounded parameter expressions,the fast and accurate grounded parameter measurement in distribution power system is realized by exploring the system resonance frequency.The correctness of proposed method is verified by PSCAD/E MTDC simulation.It is shown that this method has the high precision and wide application.

关 键 词：谐振测量 配电网 对地参数 变频信号 阻尼电阻 

分 类 号：TM835[电气工程—高电压与绝缘技术]