电力系统保护与控制2024，Vol.52Issue(1)：1-12,12.DOI:10.19783/j.cnki.pspc.230122
电网不对称故障下MMC自适应相功率均衡控制策略
Adaptive leg-balancing control strategy of an MMC in an asymmetric AC grid fault
摘要
Abstract
A modular multilevel converter(MMC)has the problem of unbalanced power in asymmetric fault conditions.The conventional control method based on DC circulating current injection will cause asymmetry of arm current,resulting in unequal current of each phase.The method based on zero-sequence voltage injection may lead to over modulation and endanger the safe and stable operation of the system.Given the limitations of traditional leg-balancing control strategies,an adaptive leg-balancing control strategy of an MMC with asymmetric faults is proposed.First,the principle of leg-balancing based on zero-sequence voltage and DC circulating current injection is analyzed,and the limitations of different methods are pointed out.Second,the overmodulation boundary of the zero-sequence voltage injection method is studied,and the phase power distribution coefficient is introduced.Then the optimization method for a leg-power distribution coefficient with different faults is given and an adaptive leg-balancing control strategy of the MMC based on the coordination of zero-sequence voltage and DC circulating current is proposed.Finally,the correctness and effectiveness of the mechanical analysis and the proposed control strategy are verified by simulation.关键词
模块化多电平换流器/相功率均衡/桥臂电流控制/不对称故障/零序电压注入Key words
modular multilevel converter/leg-balancing control/arm current control/unbalanced grid conditions/zero-sequence voltage injection引用本文复制引用
于吉,尹项根,赖锦木,韩翔宇,陈卫,胡家玄,窦真兰,孙沛..电网不对称故障下MMC自适应相功率均衡控制策略[J].电力系统保护与控制,2024,52(1):1-12,12.基金项目
国家电网有限公司科技项目资助(5400-20219953A-0-5-ZN) This work is supported the Science and Technology Project of State Grid Corporation of China(No.5400-20219953A-0-5-ZN). （5400-20219953A-0-5-ZN）
