摘要
最近电平逼近调制(NLM)是模块化多电平变换器(MMC)中最常用的调制方式。电平数较少时,NLM的输出电压电流谐波严重畸变,使其无法用于电平数较少的变频调速场合。该文通过详细分析NLM下无差拍电流控制的开关过程,指出NLM调制下MMC无差拍电流控制具有滞环特性。定量分析了NLM下MMC无差拍电流控制的滞环环宽,得到了滞环环宽和输出电流波动范围的表达式。同时,设计了MMC背靠背变频调速系统的综合控制方案。与传统方案相比,所提方案具有控制结构简单、开关频率低、环流抑制容易实现和动态特性好等优点。在Matlab/Simulink中搭建了十一电平背靠背MMC中高压变频调速模型,验证了所提控制方案的正确性和有效性。
Nearest level modulation(NLM)is the most commonly used modulation method for modular multilevel converter(MMC).When the number of levels is small,the output voltage and current harmonics of the NLM are severely distorted,and it cannot be used in MMC based medium-voltage motor drive system.In this paper,the switching process of the deadbeat current control under NLM is analyzed in detail,and it is pointed out that the MMC deadbeat current control under NLM modulation has hysteresis characteristics.The hysteresis loop width of MMC deadbeat current control under NLM is quantitatively analyzed,and the expression of hysteresis loop width and output current fluctuation range is obtained.At the same time,the integrated control scheme of MMC based motor drive system is designed.Compared with the traditional scheme,the proposed scheme has the advantages of simple control structure,low switching frequency,easy realization of circulating current suppression and good dynamic characteristics.The 11-level back-to-back MMC motor drive model was built in Matlab/Simulink to verify the correctness and effectiveness of the proposed control scheme.
作者
易灵芝
黄晓辉
黄守道
荣飞
刘罗
Yi Lingzhi;Huang Xiaohui;Huang Shoudao;Rong Fei;Liu Luo(Hunan Province Engineering Research Center for Multi-Energy Collaborative Control Technology Xiangtan University,Xiangtan 411105 China;College of Electrical and Information Engineering Hunan University,Changsha 410082 China)
出处
《电工技术学报》
EI
CSCD
北大核心
2020年第6期1303-1315,共13页
Transactions of China Electrotechnical Society
基金
国家自然科学基金项目(61572417)
国家自然科学基金重点项目(51737004)资助。
关键词
模块化多电平变换器
中高压变频调速
最近电平逼近调制
无差拍控制
滞环特性
Modular multilevel converter
medium-voltage motor drive
nearest level modulation
deadbeat current control
hysteresis characteristics
