10kV电网过电压监测装置设计及实测与仿真对比分析  

Design of Overvoltage Monitoring Device for 10 kV Power Grid and Contrastive Analysis of Its Measured and Simulation Waveforms

作　　者：周凯[1] 熊庆[1] 何珉[1] 冉立[1] 

机构地区：[1]四川大学电气信息学院,成都610065

出　　处：《高电压技术》2015年第1期35-41,共7页High Voltage Engineering

摘　　要：为了解雷电过电压从输电线到变电站的传播过程以及过电压的波形特征和影响因素,采用基于两级阻容分压的10 kV电网过电压在线监测装置,采集到变电站10 kV母线上雷电过电压,并对反击雷电过电压波形进行了分析。实测反击雷电过电压波形包含振荡,并且幅值≤50 kV。利用PSCAD/EMTDC建立传输线和变电站的电磁暂态模型,仿真分析了母线上并联馈线、容性设备,以及避雷器动作对过电压波形的影响。仿真结果表明反击雷电过电压波形中的短暂上升沿是由绝缘子闪络引起。母线上并联容性设备使过电压振荡加强,并联馈线使过电压波形产生周期性振荡,并且馈线数量越多,振荡周期越短。受避雷器动作的影响,母线上反击雷电过电压迅速衰减,过电压波形包含不规则周期性振荡,并且过电压幅值被限制到50 kV。To understand the propagation process of lightning overvoltage transmitting from power lines to substations and the overvoltage＇s waveform characteristics and impact factors, we used an on-line monitoring device based on two-stage capacitive/resistnr voltage division for 10 kV grid to measure the lightning overvoltage on a 10 kV bus, and analyzed the waveforms of back flashover lightning overvoltage. The obtained overvoltage waveforms have oscillation, and their amplitudes are less than 50 kV. We also built electromagnetic transient models of substations and transmission lines using PSCAD/EMTDC, and then discussed the influences of feeders, capacitive equipment, and arrester action on the overvoltage waveforms through simulations. The results show that the short rising edge in lightning overvoltage is caused by flashover on insulators. Capacitive equipment connected to the bus in parallel will strengthen the oscillations, while feeders can cause periodical oscillations in the overvoltage waveforms. Meanwhile, the oscillation periods decrease with the increase of feeder number. Due to the effect of arrester action, back flashover lightning overvoltage attenuates rapidly; its waveform has irregular oscillations, and its amplitude is limited to 50 kV.

关 键 词：10kV配电网 在线监测 反击 雷电过电压 PSCAD/EMTDC 电磁暂态分析 

分 类 号：TM863[电气工程—高电压与绝缘技术]