中国电机工程学报2018，Vol.38Issue(4)：1143-1156,后插20,15.DOI:10.13334/j.0258-8013.pcsee.170600
基于模块化多电平换流器的直流电网小信号建模
Small Signal Modeling of MMC-based DC Grid
摘要
Abstract
This paper proposed a generic small signal modeling method for DC grid based on modular multilevel converter (MMC) under balanced AC system. The entire system is divided into three subsystems: AC system, MMC and DC system, which makes it easily extendible to fit arbitrary topology of DC grid in a modular way. The internal dynamics of MMC including arm circulating current and total capacitor voltage, and the control system dynamics including phase lock loop, generic controller, circulating current suppression controller, and signal filters are modeled, which provides the foundation for analyzing the impacts of various parameters on the small-signal stability. According to the deduced coupling equation related to MMC internal electric quantities and AC/DC networks, the equivalent Thevenin circuits for MMC AC/DC-side are proposed. The link equations for MMC model and AC system and DC networks are then deduced. By linearizing each subsystem and link equations, the small-signal model for the whole system is automatically produced without too much manual burden, which simplifies the deduction of small-signal model for MMC-DC grid a lot. The correctness of the modeling method is validated by comparing the step response of the electromagnetic model, the deduced state-space model and the small-signal model based on a four-terminal MMC DC grid system. The impact of control parameters on the small-signal stability of the test system is analyzed through root locus and eigenvalue sensitivities.关键词
模块化多电平换流器/直流电网/小信号模型/线性化模型/模块式建模Key words
modular multilevel converter/dc grid/small signal model/linearized model/modular modeling分类
信息技术与安全科学引用本文复制引用
鲁晓军,林卫星,向往,文劲宇..基于模块化多电平换流器的直流电网小信号建模[J].中国电机工程学报,2018,38(4):1143-1156,后插20,15.基金项目
国家重点研发计划项目(2016YFB0901002). Project Supported by National key research and development program of China (2016YFB0901002). （2016YFB0901002）
