光伏电源对变压器保护的影响及应对方案  

Influence of Photovoltaic Power Supply on Transformer Protection and Corresponding Solutions

作　　者：范铭豪 韩笑[1] 郭浩然 赵耀 石恒杨 Fan Minghao;Han Xiao;Guo Haoran;Zhao Yao;Shi Hengyang(School of Electrical Engineering,Nanjing Institute of Technology,Nanjing Jiangsu 211167,China)

机构地区：[1]南京工程学院电力工程学院,江苏南京211167

出　　处：《电气自动化》2025年第1期36-39,共4页Electrical Automation

基　　金：国家自然科学基金资助项目(52107098)。

摘　　要：针对光伏电源产生二次谐波造成并网变压器在发生区内故障时制动元件误闭锁差动保护的问题,提出了一种高谐波含量下的区内故障识别方案。分析了光伏变流器低电压穿越策略下二次谐波产生的机理,并根据区内故障及变压器空投励磁涌流时电压电流特性,设计一种新判据。通过PSCAD/EMTDC电磁暂态仿真软件搭建光伏并网系统模型,来验证新方案的有效性和可靠性。结果表明:新方案能够有效防止光伏变流器故障时产生二次谐波导致的变压器差动保护拒动,解决了变压器差动保护在新能源并网中适应性不足的难题。A fault identification scheme for high harmonic content in grid connected transformers was proposed to address the issue of differential protection being mistakenly locked by the braking element in the event of an internal fault caused by the generation of second harmonics in photovoltaic power sources.The mechanism of second harmonic generation was analyzed under the low voltage ride through strategy of photovoltaic converters,and a new criterion was designed based on the voltage and current characteristics of faults in the fault occurrence area and transformer airdrop excitation inrush current.A photovoltaic grid-connected system model was built using PSCAD/EMTDC electromagnetic transient simulation software to verify the effectiveness and reliability of the new scheme.The results show that the new scheme can effectively prevent the rejection of transformer differential protection caused by second harmonic generation during photovoltaic converter faults,and solve the problem of insufficient adaptability of transformer differential protection in new energy grid connection.

关 键 词：光伏并网 变压器 低电压穿越控制 二次谐波 差动保护 

分 类 号：TM73[电气工程—电力系统及自动化]