摘要
提出一种应用于模块化多电平变换器(MMC)的混合调制策略,该方法融合了最近电平逼近调制(NLM)与脉宽调制(PWM)策略。利用NLM算法求得输出电平数,引入子模块直流电压瞬时值对阶梯数进行修正,在此基础上求得PWM波,并确保在任意时刻MMC每桥臂中有且仅有一个子模块处于PWM,以减少系统损耗。与此同时,采用电容电压排序的方法选择PWM工作子模块,并对各子模块进行了电压均衡控制。样机验证了其正确性及先进性。
This paper proposes a hybrid modulation method of modular multilevel converter（MMC） which combines the nearest level modulation （NLM） and pulse width modulation （PWM）.The output voltage level is calculated by NLM algorithm.The instantaneous value of submodule DC voltage is introduced to modify the output voltage level and ob- tain the PWM modulating wave.At any time, there is only one module works in PWM mode per arm of MMC in or- der to reduce the switching loss.The ca-pacitor voltage balance control method based on voltage sorting is also intro- duced.Accordingly, the validity and advancement of the modulation strategy are verified by the prototype.
出处
《电力电子技术》
CSCD
北大核心
2015年第12期59-61,共3页
Power Electronics
基金
国家863计划(2011AA05A113)~~
关键词
变换器
混合调制
均衡控制
converter
hybrid modulation
balance control
