摘要
在模块化多电平变换器(MMC)中,大量悬浮电容的电压平衡控制是保证系统稳定可靠工作的前提条件。提出了基于载波层叠(CD)PWM技术的选择性循环虚拟映射(VLM)电压平衡控制策略,以解决传统CD-PWM技术中MMC子模块开关频率不一致的问题;建立虚拟子模块与实际子模块之间的选择性VLM关系,无需所有子模块排序操作。实验结果表明,采用所提出的电压均衡控制策略能在较低开关频率下,实现了MMC各功率单元间有功能量的平均分配和直流电容电压的均衡。
In the modular multilevel converter（MMC）,the voltage balance control of large quantities of suspended ca- pacitor is a prerequisite to ensure the stability and reliability of system.A strategy of voltage balance control, selective virtual loop mapping （VLM） which is based on carrier disposition （CD） PWM is proposed, the problem that switching frequency of MMC sub-module is inconsistent in the traditional CD-PWM technology is solved, and the relationship of selective VLM between virtual sub-modules and actual sub-modules is established without sorting operation by all sub-modules.Experimental results show that the proposed strategy of voltage balance control can realize average distri- bution of active power and equalization of DC capacitor voltage in each sub-module at a lower switching frequency.
出处
《电力电子技术》
CSCD
北大核心
2015年第11期77-80,共4页
Power Electronics
关键词
变换器
电压均衡控制
载波层叠
循环虚拟映射
converter
voltage balance control
carrier disposition
virtual loop mapping
