Application of MMC with Embedded Energy Storage for Overvoltage Suppression and Fault Ride-through Improvement in Series LCCMMC Hybrid HVDC System  

作　　者：Xiaodong Li Zheng Xu Zheren Zhang 

机构地区：[1]Department of Electrical Engineering,Zhejiang University,Hangzhou 310027,China [2]IEEE

出　　处：《Journal of Modern Power Systems and Clean Energy》2023年第3期1001-1013,共13页现代电力系统与清洁能源学报（英文）

摘　　要：The series line-commutated converter(LCC)and modular multilevel converter(MMC)hybrid high-voltage direct current(HVDC)system provides a more economical and flexible alternative for ultra-HVDC(UHVDC)transmission,which is the so-called Baihetan-Jiangsu HVDC(BJ-HVDC)project of China.In one LCC and two MMCs(1+2)operation mode,the sub-module(SM)capacitors suffer the most rigorous overvoltage induced by three-phase-to-ground fault at grid-side MMC and valve-side single-phase-to-ground fault in internal MMC.In order to suppress such huge overvoltage,this paper demonstrates a novel alternative by employing the MMC-based embedded battery energy storage system(MMC-BESS).Firstly,the inducements of SM overvoltage are analyzed.Then,coordinated with MMC-BESS,new fault ride-through(FRT)strategies are proposed to suppress the overvoltage and improve the FRT capability.Finally,several simulation scenarios are carried out on PSCAD/EMTDC.The overvoltage suppression is verified against auxiliary device used in the BJ-HVDC project in a monopolar BJ-HVDC system.Further,the proposed FRT strategies are validated in the southern Jiangsu power grid of China based on the planning data in the summer of 2025.Simulation results show that the MMC-BESS and proposed FRT strategies could effectively suppress the overvoltage and improve the FRT capability.

关 键 词：Line-commutated converter(LCC) modular multilevel converter(MMC) MMC-based embedded battery energy storage system(MMC-BESS) fault ride-through(FRT)capability overvoltage suppression 

分 类 号：TM721.1[电气工程—电力系统及自动化]