摘要
对于地区二次变电站其中性点一般不直接接地,随着高密度分布式电源的接入,若输电线路发生接地故障,会导致该变压器中性点电压升高,甚至会击穿,进一步影响并网点电压。文中针对含光伏的主动配电网,分析了主变中性点击穿前后、线路保护动作前后,影响并网点电压的主要因素,并画出含光伏的主动配电网的各序网络图,推导光伏电源并网点电压理论计算公式,同时,文章通过PSCAD仿真验证了公式的正确性,比较了主变中性点击穿前后,分布式电源并网点电压变化规律。
For a typical radiation type 220-110-10 kV grid,the neutral point of the 110 kV side transformer is a direct grounding system,but not the neutral point of each transformer is directly grounded.If the ground fault occurs on the 110 kV transmission line,the neutral point voltage of the 110 kV transformer will rise.Even the neutral point voltage breakdown will happen.This paper will draw out the sequence network including photovoltaic power and calculate formula of distributed power and network voltage theory.Aiming at the typical power grid,the main changes from the neutral breakdown occurred will be discussed respectively at the same time.By analyzing the formula,the main factors affecting the voltage are obtained.The conclusion is of practical value.Meanwhile,the accuracy of the conclusion is verified by PSCAD simulation.The distributed power and the operation of point voltage are compared considering work condition of the main transformer.
作者
竺庆茸
李晗
李先允
王书征
Zhu Qingrong;Li Han;Li Xianyun;Wang Shuzheng(School of Electrical Engineering,Nanjing Institute of Technology,Nanjing 211167,China)
出处
《电测与仪表》
北大核心
2019年第4期101-106,共6页
Electrical Measurement & Instrumentation
基金
江苏省普通高校研究生科研创新计划项目(SJZZ16_0291)
江苏省普通高校研究生科研创新计划项目(SJCX17_0445)
江苏省高校自然科学研究面上项目(16KJB470006)
南京工程学院引进人才科研启动基金项目(YKJ201519)
关键词
不对称故障
分布式电源
中性点电压击穿
并网点电压
asymmetric faults
distributed power supplies
neutral point voltage breakdown
grid-connected point voltage
