一种特高压直流输电线路单端电压暂态保护原理

摘要

平波电抗器、直流滤波器、PLC滤波器构成特高压直流输电线路现实边界。分析特高压直流输电线路边界以及特高压直流输电线路的频率特性，研究特高压直流输电线路以及边界对故障暂态电压信号高频量的衰减作用。分析现有特高压直流输电线路暂态保护原理的保护范围，指出现有利用保护元件区分本侧区内外故障的特高压直流输电线路暂态保护原理并不能实现特高压直流输电线路全线保护。综合考虑特高压直流输电线路边界和线路对故障暂态信号高频量的衰减作用，提出利用保护元件区分对侧区内外故障的特高压直流输电线路单端电压暂态保护原理。建立云广特高压直流输电系统实际参数仿真模型，对所提出的特高压直流输电线路单端电压暂态保护原理进行仿真验证。%The smoothing reactor, DC filter and PLC filter form the physical boundary of UHVDC transmission line. The frequency characteristics of UHVDC transmission line and line boundary are analyzed, and the attenuation of high frequency fault transient signal caused by UHVDC transmission line boundary and transmission line is studied. The protection area of transient based protection of UHVDC transmission line which is widely used now is analyzed, and it is concluded that the transient based protection method can not protect the whole transmission line. Considering the attenuation of high frequency fault transient signal caused by UHVDC transmission line boundary and transmission line, single-ended transient based voltage protection method of UHVDC transmission line which uses protector to distinguish the opposite inside fault from outside fault is studied. The actual parameter simulation model is built, and the single-ended transient based voltage protection method studied in this paper is simulated.