中国电机工程学报2018，Vol.38Issue(1)：258-265,后插27,9.DOI:10.13334/j.0258-8013.pcsee.162282
电网电压不对称工况下模块化多电平变换器控制策略
Modular Multilevel Converter Control Strategy Under Unbalanced Grid Condition
摘要
Abstract
Upon the power analysis of modular multilevel converter (MMC), this paper proposed a comprehensive control strategy for the DC-link voltage, the capacitor voltages and the AC-side currents of MMC under unbalanced grid condition. Multi-hierarchy method was adopted to control the capacitor voltage. Under unbalanced grid condition, the AC-side currents were controlled to be symmetrical by adjusting active power distribution among three legs of MMC. Inner current loop employed arm current direct control, which can simultaneously control AC-side currents, DC bus current and circulating currents, removing the need for the three-sequence AC-side current controllers and the three-sequence circulating current suppressing controllers under unbalanced grid condition. A zero-sequence current canceller was proposed to add in arm current reference, and this could eliminate the zero-sequence fundamental-frequency current which is caused by the asymmetrical arm power losses and will flow to the DC-link. A 10kVA experimental prototype of the three-phase MMC was developed. The experiment results verify the feasibility and effectiveness of proposed strategy.关键词
电网电压不对称/零序电流抑制器/模块化多电平变换器/桥臂电流控制Key words
unbalanced grid condition/zero-sequence current canceller/modular multilevel converter (MMC)/arm current control分类
信息技术与安全科学引用本文复制引用
欧朱建,王广柱..电网电压不对称工况下模块化多电平变换器控制策略[J].中国电机工程学报,2018,38(1):258-265,后插27,9.基金项目
国家自然科学基金项目(51541708). Project Supported by National Natural Science Foundation of China (51541708). （51541708）
