摘要
具有故障闭锁功能的钳位双子模块型模块化多电平换流器（clamp double submodule-modular multilevel converter,CDSM-MMC）适用于大容量输电工程,为防止交流侧故障后可能引起的直流保护误动,需分析交流侧故障对直流侧的影响。首先,分析交流侧发生短路故障后,CDSM-MMC子模块电容的充放电情况,以及桥臂电流回路。然后,根据基尔霍夫定律与叠加原理,分析交流侧故障后,直流侧电压及电流特征,并在PSCAD中进行仿真验证。交流故障后,直流侧电流随桥臂电容电压变化;两相短路后,直流电压基本不变;单相接地短路与两相接地短路后,直流电压包含交流分量,其频率与幅值受到交流中性点接地方式影响。最后针对CDSM-MMC直流侧保护,给出部分参考建议。
The clamped double submodule-modular multilevel converter（CDSM-MMC） is appropriate for large-capacity transmission projects. In order to prevent the DC-side protection malfunction after AC-side faults, the analysis on impact of AC faults on DC-side electrical quantities is significant. Firstly, the charging and discharging scenarios of capacitors in submodules of the CDSM-MMC, and current circuits of bridge arms after AC-side short-circuit faults were analyzed. Subsequently, based on Kirchhoff＇s laws and the superposition principle, the characteristics of DC-side current and voltage were deduced, and verified via simulations in PSCAD/EMTDC. According to the analysis, the DC current changes with the bridge capacitor voltage after AC-side faults. The DC voltage is basically unchanged after phase-to-phase faults, while after single-phase and two-phase grounded faults, the DC voltage contains AC components, whose frequency and amplitude are influenced by the grounding mode of the AC side. Finally, recommendations in terms of the DC-side protection of CDSM-MMCs are presented.
作者
戴志辉
朱惠君
严思齐
苏怀波
DAI Zhihui;ZHU Huijun;YAN Siqi;SU Huaibo(Hebei Key Laboratory of Distributed Energy Storage and Microgrid （North China Electric Power University）, Baoding 071003, Hebei Province, China)
出处
《中国电机工程学报》
EI
CSCD
北大核心
2018年第12期3568-3577,共10页
Proceedings of the CSEE
基金
国家重点基础研究发展计划项目(2016YFB0900203)
河北省自然科学基金项目(E2018502063)
教育部中央高校基本科研业务费专项基金(2017MS096)~~
关键词
钳位双子模块型模块化多电平换流器
交流故障
接地方式
故障分析
交互影响
clamp double submodule-modular multilevel converter （CDSM-MMC）
AC-side fault
grounding mode
fault analysis
interactive impact
