摘要
针对现有接地故障选线方法受系统参数不对称、互感器采样不同步影响,对于高阻接地故障馈线难以准确判别的问题,笔者提出了基于ZNy11-Dyn7无源降压消弧器件的高阻接地故障选线新方法。首先,提出了基于ZNy11-Dyn7型变压器的无源电压调控结构,分析了ZNy11-Dyn7型无源降压消弧器件接入系统后的运行特性。基于ZNy11-Dyn7型无源器件电压调控原理,在系统发生接地故障前后,分别通过无源器件投入调控系统电压,计算故障前后各馈线零序导纳值,消除系统参数不对称、互感器采样不同步影响,主动构造故障前后各馈线的零序导纳相角差,实现故障线路的准确判别。在PSCAD/EMTDC环境下搭建了10 kV配电网接地故障模型验证所提选线方法有效性,结果表明在不接地系统、谐振接地系统下发生不同过渡电阻接地故障时,所提方法均能准确判别故障线路,耐过渡电阻能力可达24 kΩ。
The existing grounding fault line selection methods are affected by system parameter asymmetry and asynchronous transformer sampling,which makes it difficult to accurately distinguish high resistance grounding fault feeder lines,the author proposes a new method for high resistance grounding fault line selection based on ZNy11-Dyn7 passive step-down arc suppression device.Firstly,a passive voltage regulation structure based on ZNy11-Dyn7 transformer was proposed,and the operational characteristics of ZNy11-Dyn7 passive step-down and arc suppression devices after being connected to the system were analyzed.Based on the voltage regulation principle of ZNy11-Dyn7 passive components,before and after a ground fault occurs in the system,the voltage of the system is regulated through the input of passive components.The zero sequence admittance values of each feeder before and after the fault are calculated to eliminate the influence of system parameter asymmetry and asynchronous transformer sampling.The zero sequence admittance phase difference of each feeder before and after the fault is actively constructed,achieving accurate identification of the faulty line.Under PSCAD/EMTDC environment,a 10 kV distribution network ground fault model is built to verify the effectiveness of the proposed line selection method.The results show that the proposed method can accurately identify fault lines when different transition resistance grounding faults occur in ungrounded system and resonant grounding system,and the resistance to transition resistance can reach 24 kΩ.
作者
陈虓
刘红文
黄继盛
喻锟
曾祥君
曾超
CHEN Xiao;LIU Hongwen;HUANG Jisheng;YÜKun;ZENG Xiangjun;ZENG Chao(Lincang Power Supply Company,Yunnan Electric Power Grid Co.,Ltd.,Lincang 677000,China;Electric Power Research Institute,Yunnan Electric Power Grid Co.,Ltd.,Kunming 650217,China;Hunan Province Key Laboratory of Smart Grids Operation and Control,School of Electrical and Information Engineering,Changsha University of Science and Technology,Changsha 410114,China)
出处
《电瓷避雷器》
CAS
北大核心
2023年第6期45-54,共10页
Insulators and Surge Arresters
基金
云南电网有限责任公司科技项目(编号:YNKJXM20210175)。
