摘要
模块化多电平变换器由于其扩展的容易性,在高压直流输电领域具有突出的优势,针对MMC固有的环流问题,提出了一种有效的环流控制策略,该控制策略既包含环流的利用也包含环流的抑制。首先通过对MMC内部运行机理的分析,得到平衡上、下桥臂子模块电容电压的条件,分析表明可通过环流控制实现上、下母线电容电压和与差的控制,并设计了基于PI与PR调节器的环流利用策略;其次针对环流中的有害成份,提出了一种基于多重PR控制器的环流抑制方案;最后通过算例分析,验证了所提环流控制策略的正确性和有效性。
In the field of high voltage DC transmission,the modular multilevel converter（MMC）has gained prominent attention because of the advantage of easily extension.This paper proposed an effective control strategy to solve the inherent circulating current problem of MMC.This control strategy includes both the utilization and the suppression of circulating current.Firstly,the internal mechanism of MMC is analyzed to get the condition of capacitor voltage balancing for the up and down arms.The analysis indicates that the difference and sum of the capacitor voltage balancing for the up and down arms can be controlled by the circulating current.And then,the circulating current utilization control strategy was designed based on PI and PR controllers.In addition,the circulating current suppression control strategy based multi-PR controllers was designed to eliminate the harmful component.Finally,the correctness and effectiveness of the proposed strategy was verified through examples.
出处
《水电能源科学》
北大核心
2016年第10期202-206,共5页
Water Resources and Power
关键词
模块化多电平变换器
高压直流输电
环流利用
环流抑制策略
modular multi-level converter
HVDC
circulating current utilization
circulating current suppression control
