A Comprehensive DC Short-Circuit Fault Ride Through Strategy of Hybrid Modular Multilevel Converters (MMCs) for Overhead Line Transmission
A Comprehensive DC Short-Circuit Fault Ride Through Strategy of Hybrid Modular Multilevel Converters (MMCs) for Overhead Line Transmission
复制标题
DOI：
10.1109/tpel.2015.2513426
复制
发表时间：
2016-11
影响因子：
6.7
通讯作者：
Shenghui Cui;S. Sul
中科院分区：
文献类型：
--
作者：
Shenghui Cui;S. Sul
模块化多电平换流器（MMC）是基于电压源换流器的高压直流输电（VSC-HVDC）的一种很有前途的选择。对于架空输电线路，非永久性直流短路故障时有发生，直流短路故障管理是一个重要问题。本文提出了一种综合的直流短路故障穿越（FRT）策略的混合MMC，它结合了半桥子模块和全桥子模块。通过所提出的方法，基于混合MMC的VSC-HVDC系统能够穿越极间短路故障，支持交流电网作为静止同步补偿器。此外，在极-地短路故障的情况下，输电系统仍然可以传输额定有功功率的一半，而不增加功率半导体应力或要求电气设备的更高绝缘水平。所提出的方法，确保成功调节臂电流和子模块电容器电压在FRT过程中。计算机仿真和实验结果验证了该策略的有效性。
The modular multilevel converter (MMC) is a promising candidate for voltage-sourced-converter-based high-voltage direct current (VSC-HVDC) transmission. The dc short-circuit fault management is a crucial issue especially for overhead line transmission, where the nonpermanent dc short-circuit faults occasionally occur. In this paper, a comprehensive dc short-circuit fault ride through (FRT) strategy is proposed for a hybrid MMC which combines half-bridge submodules and full-bridge submodules. By the proposed method, the hybrid MMC-based VSC-HVDC system is able to ride through a pole-to-pole short-circuit fault supporting the ac grid as a static synchronous compensator. Moreover, the transmission system can still transmit one-half of the rated active power in case of a pole-to-ground short-circuit fault without increasing power semiconductor stresses or requiring higher insulation levels of the electric equipment. The proposed method ensures successful regulation of arm currents and submodule capacitor voltages during the FRT process. Validity of the proposed strategy is verified by both computer simulation and experiment results.