半波长输电线路的工频暂态过电压  

Power Frequency Temporary Overvoltage on Half-wave Length AC Transmission Lines

作　　者：张黎[1] 邹亮[1] 吕鑫昌[1] 李庆民[2] 王冠[1] 师伟[1] 

机构地区：[1]山东大学电气工程学院,济南250061 [2]华北电力大学(北京)电气与电子工程学院,北京102206

出　　处：《高电压技术》2012年第10期2728-2734,共7页High Voltage Engineering

基　　金：国家电网公司科技项目(B11-10-023)~~

摘　　要：半波长输电线路因结构的特殊性,其过电压水平与常规短线路有显著的不同,以致内部过电压成为半波长输电亟待解决的关键技术问题之一,因此研究了半波长输电线路中的工频暂态过电压。首先分析了半波长输电线路的功角特性,从有、无考虑电源阻抗两种情况阐述了其空载电容效应。采用典型的特高压输电线路参数,构建了半波长输电线路的仿真模型,与短距离线路的空载电容效应做对比。然后基于不对称故障和甩负荷两种工况,重点研究了线路传输功率、人工调谐网络类型、线路长度等因素对工频暂态过电压水平的影响,并与常规特高压输电线路进行了对比分析。仿真结果表明,发生不对称单相接地故障时,半波长输电线路的工频过电压最为严重,而甩负荷时的影响相对较低;较之π型和T型调谐的半波长输电线路,电容型调谐的半波长输电线路无论发生不对称接地故障还是甩负荷引起的工频过电压水平均更低。Due to its unique structure,the over-voltage level of the half-wavelength transmission lines is significantly different from that of the conventional short lines,which makes the internal over-voltage one of the key technical issues for developing the half-wavelength transmission technology.Thus,we investigated the power frequency temporary overvoltage on half-wave length AC transmission lines.Firstly,the power-angle characteristics of the half-wavelength transmission lines were briefly analyzed.The capacitance effect of unloaded lines according to the half-wavelength transmission lines were also described with and without considering the source impedances respectively.Based on typical parameters of the ultra-high voltage transmission lines,a simulation model for the half-wavelength transmission lines was established,of which the capacitance effect of unloaded lines was compared with that of short distance transmission lines.Secondly,the impacts of the transmission power,the man-made tuning network type and the line length on the power frequency over-voltages were emphatically researched under two operating conditions,i.e.the asymmetrical faults and the load shedding,and the results were compared with that along the conventional UHV transmission lines.The simulation results shows that,the power frequency overvoltage of the half-wavelength transmission lines is much more serious under asymmetrical fault than that under load shedding;in both situations,the power frequency overvoltage on the half-wavelength transmission lines under capacitance type tuning is lower than that by π type and T type tuning.

关 键 词：半波长线路 工频过电压 电容效应 不对称故障 甩负荷 调谐网络 

分 类 号：TM863[电气工程—高电压与绝缘技术]