受端混联LCC-VSC特高压直流输电系统故障穿越方法  

Fault ride-through method of inverter hybrid cascade LCC-VSC UHVDC transmission system

作　　者：王冰倩 赵文强[1] 侍乔明 田杰[1] 常昊添 WANG Bingqian;ZHAO Wenqiang;SHI Qiaoming;TIAN Jie;CHANG Haotian(NR Electric Co.,Ltd.,Nanjing 211102,China)

机构地区：[1]南京南瑞继保电气有限公司,江苏南京211102

出　　处：《电力工程技术》2021年第6期69-76,共8页Electric Power Engineering Technology

基　　金：国家重点研发计划资助项目(2016YFB0900602)。

摘　　要：针对受端由电网换相换流器(LCC)和电压源换流器(VSC)级联的混合直流输电系统中VSC在交流故障穿越时子模块过压的问题,文中提出在受端VSC直流侧安装耗能设备以抑制VSC子模块过压的方法,对比分析了基于直流斩波耗能电阻、泄流晶闸管和可控避雷器3种耗能设备的交流故障穿越原理及策略。基于PSCAD/EMTDC仿真平台搭建了包含工程实际控制保护主机程序的受端混联LCC-VSC特高压直流仿真模型,对比分析了3种耗能设备的交流系统故障穿越特性,结果表明在受端VSC直流侧安装耗能设备可以有效抑制子模块过压,实现交流故障可靠穿越。其中可控避雷器方案具有控制原理简单、可靠性高等优点,更适用于受端混联LCC-VSC特高压直流输电系统。In a hybrid cascade UHVDC transmission system which the receiving end consists of a line commutated converter(LCC)in series with multiple parallel voltage source converters(VSC),the VSC has sub-module overvoltage problems when the AC grid fault.A method to suppress the overvoltage of the sub-module by installing energy-consuming devices on the DC side of VSC is proposed.The fault ride-through principles and strategies based on energy-consuming devices as DC Chopper,thyristor and controllable metal oxide surge arrester(CMOA)are compared and analyzed.Based on the PSCAD/EMTDC simulation platform,a hybrid cascade UHVDC simulation model containing the actual control and protection host program is built,and the AC fault ride-through characteristics based on three energy-consuming devices are compared and analyzed.The results show that the method of installing energy-consuming devices on the DC side of the VSC can effectively suppress the overvoltage of the sub-module and achieve reliable AC fault ride-through.The CMOA scheme has the advantages of simple control principle and high reliability,and it is suitable to be the energy-consuming devices for the hybrid cascade UHVDC transmission system which the receiving end consists of LCC and multiple VSC.

关 键 词：电网换相换流器(LCC) 电压源换流器(VSC) 故障穿越 直流斩波耗能电阻 泄流晶闸管 可控避雷器 

分 类 号：TM723[电气工程—电力系统及自动化]