相邻变压器空载合闸对光伏输出电流二次谐波分量影响的研究  

Research on the Impact of No-load Closing of Adjacent Transformer on the Second Harmonic Current Components of Photovoltaic Power

作　　者：郑涛 王铭灏 于吉 陈争光 顾琦 文芳 罗来龙 陈禹志 ZHENG Tao;WANG Minghao;YU Ji;CHEN Zhengguang;GU Qi;WEN Fang;LUO Lailong;CHEN Yuzhi(State Key Laboratory of Alternate Electrical Power System With Renewable Energy Sources(North China Electric Power University),Changping District,Beijing 102206,China;State Key Laboratory of Power Grid Safety and Energy Conservation(China Electric Power Research Institute),Haidian District,Beijing 100192,China;State Grid Tibet Electric Power Company,Lhasa 850000,Tibet Autonomous Region,China)

机构地区：[1]新能源电力系统国家重点实验室(华北电力大学),北京市昌平区102206 [2]电网安全与节能国家重点实验室(中国电力科学研究院有限公司),北京市海淀区100192 [3]国网西藏电力有限公司,西藏自治区拉萨市850000

出　　处：《电网技术》2021年第2期570-577,共8页Power System Technology

基　　金：中国电力科学研究院有限公司科技项目“阿里–藏中联网工程保护适应性分析”(JBB51201901542)。

摘　　要：随着光伏渗透率的提高,含有大量电力电子元件的光伏并网系统改变了电网的谐波特性。当相邻变压器空载合闸于光伏并网点母线时,励磁涌流引起的母线电压波动会导致光伏输出电流中含有二次谐波分量。文章以相邻变压器空载合闸为场景,介绍光伏并网系统结构及其控制策略,揭示光伏输出电流二次谐波分量的产生机理,分析光伏输出电流二次谐波对变压器差动保护的影响并提出抑制措施。最后通过仿真验证理论分析的正确性和抑制措施的有效性。With the increase of photovoltaic(PV) penetration, PV grid-connected systems containing a large number of power electronic components have changed the harmonic characteristics of the power grid. When adjacent transformer closes at the PV grid-connected busbars without load, bus voltage fluctuation caused by inrush current will result in second harmonic components in PV output. Firstly, this paper introduced the structure of PV grid-connected system and its control strategy, and then revealed the generation mechanism of the second harmonic components of PV output current under adjacent transformer closing without load. Secondly, This paper analyzed the influence of the second harmonic current of PV on the transformer differential protection. On this basis, the suppression measure was proposed. Finally, the correctness of the theoretical analysis and the effectiveness of the suppression measure was verified by simulation.

关 键 词：光伏并网系统 励磁涌流 电流二次谐波 差动保护 抑制措施 

分 类 号：TM721[电气工程—电力系统及自动化]