HVDC地中直流对交流系统影响的防范措施  

Measures to Restrain the Neutral Current of the AC Transformer in HVDC Ground Return System

作　　者：曾嵘[1] 赵杰 尚春 黎小林 王琦 牛犇[1] 何金良[1] 张波[1] 

机构地区：[1]清华大学电机系电力系统及发电设备控制和仿真国家重点实验室,北京100084 [2]南方电网技术研究中心,广州510620 [3]南方电网超高压公司,广州510620

出　　处：《高电压技术》2009年第4期919-925,共7页High Voltage Engineering

基　　金：国家自然科学基金(50407002)~~

摘　　要：针对直流输电系统处于单极大地回路运行方式时对交流电网运行带来的噪声、谐波、振动等不利影响,比较全面地对各种抑制地中直流影响的措施进行了对比分析。基于地中电流的成因与流散规律分析,提出了采用直流接地极与交流变电站选址优化、无接地极运行或多极共址运行方式、合理结构型式变压器的选择等主动防范措施减小地中直流的影响。结合作者的研究成果,就国内外目前抑制变压器中性点直流采取的注入反向电流、中性点串入电容、中性点串入电阻等措施进行了对比分析。通过分析串电阻措施的关键问题,认为该方案结构简洁,长期运行可靠性高,不会产生谐振,成本低廉,建议在现场使用。该研究成果为解决交直流电网并列运行安全稳定运行提供了有益的建议。The influences, such as sharp rising of the audible noise, harmonic and oscillation, will be found in the power system and transformer, where the HVDC transmission system operated in ground return mode. Based on the analyzing of the characteristics of the DC current distributed under ground and in the AC network, some useful measures, such as the optimization of the location of the substation and the DC grounding system, being operated with additional metal return wire, several HVDC substations sharing one grounding system, suitable structure selection of transformer, were put forward. Some measures to decrease the neutral current, such as the injection of reverse DC current, blocking capacitor and blocking resistor, were compared. Moreover, the resistor blocking solution was recommended, and some useful conclusions were drawn.

关 键 词：直流接地极 中性点直流 防范措施 反向电流法 串联电容法 串联电阻法 

分 类 号：TM721.1[电气工程—电力系统及自动化]