一种抑制多馈入特高压直流换相失败的投旁通控制策略  

A Bypass Pair Control Strategy for Commutation Failure Mitigation in Multi-infeed DC System

作　　者：张朝峰 张伟晨 饶宇飞 夏秋 李程昊 鲍超斌 ZHANG Chaofeng;ZHANG Weichen;RAO Yufei;XIA Qiu;LI Chenghao;BAO Chaobin(Electric Power Research Institute of State Grid Henan Electric Power Company,Zhengzhou 450052,China;Wuhan Qiyi Electric Limited Company,Wuhan 430074,China)

机构地区：[1]国网河南省电力公司电力科学研究院,郑州市450052 [2]武汉启亦电气有限公司,武汉市430074

出　　处：《电力建设》2022年第6期56-65,共10页Electric Power Construction

基　　金：国网河南省电力公司科技项目“特高压直流分站接入方式下多直流同时换相失败特性及抑制策略研究”(5217022000AA)。

摘　　要：换相失败是特高压直流输电系统的常见故障之一,常在送、受端交流电网引起剧烈的无功波动。投入旁通对是对直流系统进行保护的重要控制措施之一。当直流输电系统发生故障时,逆变侧保护装置动作后投入旁通对有助于达到快速停运直流输电系统,隔离故障的目的。而现在有关旁通对的研究多集中于其在直流故障中的应用,关于其在换相失败问题中的应用研究较少。通过分析旁通对控制对特高压直流输电系统送、受端电压特性的影响,论证了旁通对控制策略对换相失败后整流侧过电压、逆变侧低电压的改善作用。进而提出了一种换相失败后投旁通对的控制方法,以逆变阀组换相失败及交流电压跌落程度为旁通对控制的启动判据,根据直流运行状态对直流电流进行动态调节,然后根据受端交流系统恢复程度退出旁通对。PSCAD/EMTDC仿真表明,所提旁通对控制器在交流故障导致特高压直流换相失败后,能够起到快速隔离交直流系统、减轻无功电压波动的控制效果。As an inherent drawback of LCC-UHVDC,commutation failure often causes dramatic reactive power fluctuation in the AC power grid both on the rectifier side and the inverter side.The application of bypass pair is one of the important control strategies of DC system protection.When a fault occurs in the HVDC system,the switch of bypass pair after the protection action of the inverter side will help to achieve the purpose of stopping the HVDC system quickly and isolating the fault.At present,the research of bypass pair is mainly focused on the application under DC fault cases,whereas the application of that in commutation failure is lacking.According to the analysis of the impact of bypass control on the voltage characteristics on the rectifier side and the inverter side,this paper demonstrates the contribution of reasonable bypass control on improving the voltage characteristics of UHVDC transmission line after commutation failure.And a bypass pair control scheme is proposed,which takes the commutation failure in inverter valves and the reduction of AC bus voltage as the initialization criterion to dynamically adjust DC current.Then,the bypass pair will quit as the system recovering.The effectiveness of the proposed bypass pair control scheme on isolating AC and DC systems and reliving the reactive power and the voltage fluctuation during the transient process of AC system fault is verified in PSCAD/EMTDC.

关 键 词：特高压直流 换相失败 旁通对 电压稳定性 

分 类 号：TM773[电气工程—电力系统及自动化]