不同接线方式调压器对10kV配电网故障电流的影响  

Influence of Voltage Regulator with Different Connection Modes on Fault Current in 10 kV Distribution Network

作　　者：彭和平 端木玉 栾乐 许中 周凯 PENG Heping;DUAN Muyu;LUAN Le;XU Zhong;ZHOU Kai(Guangzhou Power Supply Bureau of Guangdong Power Grid Co.,Ltd.,Guangzhou 510620,China;Guangzhou Maritime University,Guangzhou 510725,China)

机构地区：[1]广东电网有限责任公司广州供电局,广州510620 [2]广州航海学院,广州510725

出　　处：《内蒙古电力技术》2020年第5期63-67,共5页Inner Mongolia Electric Power

摘　　要：结合广州地区10 kV配电网经小电阻接地的特点,利用PSCAD仿真软件和向量分析法,计算分析了不同接线形式下、不同单相调压比调压器的双向调压能力,以及不同接线形式调压器对故障电流的影响,为用户根据调压需求选择调压器单相调压比提供了理论依据:三角形接线调压器可以实现电压的双向调节,且对故障电流分布影响较小;开口三角形接线形式会引起系统的不平衡;星形接线会导致系统零序阻抗增大,单相接地故障时变电站无法采集到故障电流引起保护拒动。推荐在广州地区采用三角形接线的调压器,并提出了保护定值整定校验方法。根据该方案对广州地区多条用户电压异常的线路进行改造后,用户电压得到了改善,且对原有保护方案无不利影响。This paper uses PSCAD software and vector analysis method to calculate and analyze the bidirectional voltage regulation capability of voltage regulators with different connection forms and different single-phase voltage regulation ratios,which provides theoretical basis for users to select the single-phase voltage regulation ratio of voltage regulators according to voltage regulation requirements.According to the grounding characteristics of 10 kV distribution network in Guangzhou area via small resistance,the influence of different connection types of voltage regulators on fault current is calculated.Through calculation,the triangular connection voltage regulator can realize bidirectional regulation of voltage and has little influence on fault current distribution.Open delta connection will cause imbalance of the system.Star connection will cause the zero sequence impedance of the system to increase,and the failure current cannot be collected by the substation when the single-phase grounding fault occurs,causing the protection to refuse to operate.This paper recommends that a voltage regulator with triangular connection can be adopted in Guangzhou area,and proposes a method for setting and checking the protection setting value.According to the scheme recommended in this paper,several lines with abnormal user voltage in Guangzhou area have been reformed.After the renovation,the user voltage has been effectively improved and there is no adverse effect on the original protection scheme.

关 键 词：自耦变压器 调压器 零序电流 零序阻抗 三角形接线 故障电流 

分 类 号：TM421[电气工程—电器]