摘要
高压直流输电技术在大容量长距离输电和电网互联中起着重要作用,在实际工程中模块化多电平换流器(Modular Multilevel Converter, MMC)应用较广,其中电容电压均衡控制影响着输出电压质量、内部环流等,在整体系统的控制中显得尤为重要,然而传统的子模块电容均压算法存在开关频率高、损耗大等问题。从MMC的特性出发,结合最近电平逼近调制技术,提出了针对MMC电容的优化排序算法,同时采用模块变动选择法抑制相间环流,通过在MATLAB/Simulink仿真环境中搭建MMC系统验证了排序算法的可行性。优化排序算法大大降低了子模块的开关频率,同时随着子模块数的增加,电压均衡效果会越来越好,该方法适用于工程中大规模的MMC。
HVDC technology plays an important role in large-capacity long-distance power transmission and grid interconnection. In practical engineering, modular multilevel converter(MMC) is widely used, among which capacitor voltage equalization control affects the output voltage quality and internal circulating current, it is particularly important in the control of the overall system. However, the traditional sub-module capacitor voltage equalization algorithm has problems such as high switching frequency and large loss. In this paper, based on the characteristics of MMC and combining the nearest level approximation modulation technology, an optimal sorting algorithm for MMC capacitance is proposed. At the same time, module variable selection method is adopted to suppress phase-to-phase circulation. In this paper, the feasibility of the sorting algorithm is verifed by building MMC system in MATLAB/Simulink simulation environment. The optimized sorting algorithm in this paper greatly reduces the switching frequency of the sub-modules. At the same time, as the number of sub-modules increases, the voltage balancing effect will become better and better. This method is suitable for large-scale MMC in engineering.
作者
马龙
张子钰
郭希铮
MA Long;ZHANG Ziyu;GUO Xizheng(Coal Science Group Shenyang Research Institute Co.,Ltd.,Fushun 113122,China;School of Electrical Engineering,Beijing Jiaotong University,Beijing 100044,China)
出处
《电气应用》
2020年第10期68-74,共7页
Electrotechnical Application
关键词
模块化多电平换流器
优化排序算法
电容电压均衡控制
环流抑制
modular multilevel converter
optimized sorting algorithm
capacitor voltage balance control
circulating current restraining
