LCC-VSC混合直流系统LCC换流站阀过电压研究  

Valve Overvoltage of LCC Converter Station in LCC-VSC Hybrid DC System

作　　者：王磊 何慧雯 王东举[2] 周姣 WANG Lei;He Huiwen;WANG Dongju;ZHOU Jiao(China Electric Power Research Institute,Wuhan 430074,China;Zhejiang University,Hangzhou 310007,China)

机构地区：[1]中国电力科学研究院有限公司,武汉430074 [2]浙江大学,杭州310007

出　　处：《电瓷避雷器》2021年第1期90-95,共6页Insulators and Surge Arresters

基　　金：国家电网公司重点科技项目“LCC-VSC混合直流输电系统过电压与绝缘配合研究”(编号:EPRIGYKJ(2017)1642)。

摘　　要：LCC-VSC混合直流系统结合了LCC输送大容量电能,VSC适用于向弱交流电网系统输电且不发生换相失败的优点,使输电形式更加灵活。阀过电压是LCC直流换流站重要的一种过电压。建立了一个送端为LCC换流站,受端以MMC换流阀为换流器的VSC换流站的直流过电压计算模型,仿真了逆变侧有无阻断二极管两种条件下混合直流系统中LCC换流站阀过电压,并结合传统两端LCC直流系统中阀过电压的产生机理,对比传统直流阀过电压计算结果,分析了阀过电压受逆变侧VSC换流站的影响机理。结果表明阻断二极管对于限制LCC换流站阀过电压具有重要作用,需要在混合直流系统中配置该类型设备以保护整流侧换流阀。LCC-VSC hybrid DC system combines the advantages of LCC in transmitting large-capacity electric energy and VSC in power transmitting to weak AC power system without commutation failure,which makes the transmission form more flexible. Valve overvoltage is an important overvoltage in LCC DC converter station. Combining with the mechanism of valve overvoltage in traditional two-terminal LCC DC system,the author establishes a DC overvoltage calculation model of VSC converter station with LCC converter at the sending end and MMC converter at the receiving end,and simulates whether there are blocking diodes on the inverter side. Under the condition of hybrid DC system,the valve overvoltage of LCC converter station is compared with that of traditional DC valve,and the mechanism of valve overvoltage affected by VSC converter station on the inverting side is analyzed. The results show that blocking diode plays an important role in limiting valve overvoltage of LCC converter station. It is necessary to configure this type of device in hybrid DC system to protect rectifier side converter valve.

关 键 词：混合直流 阀过电压 阻断二极管 

分 类 号：TM721.1[电气工程—电力系统及自动化]