摘要
当MMC处于孤岛运行模式时,如果供电给不平衡负荷,尤其是单相负荷,将会导致负序电流的产生。然而目前已有的MMC换流器控制策略不支持孤岛运行方式下的不平衡负荷供电需求。针对该问题提出了一种适用于孤岛不平衡负荷供电需求的MMC换流器控制策略。该控制策略包含正序控制和负序控制两部分。正序控制部分输出为调制波正序分量,控制PCC点的电压幅值;负序控制部分输出为调制波的负序分量,平衡负序电流在阻抗上的压降,从而使得PCC点的电压负序分量为零,保证了PCC点的电压满足国标的要求。最后在MATLAB/Simulink仿真平台下搭建了一个双端MMC-HVDC系统,验证了该控制策略的有效性。
When MMC convertor operates in island model,if the power is supplied to the unbalanced load,especially single-phase load,negative sequence current will be generated. However,the existing island control strategy of MMC converter does not support the power supply demand of unbalanced load. To solve this problem,a novel island control strategy for MMC converter is proposed in this paper,which is suitable for the demand of unbalanced island load power supply. The control strategy includes two parts： positive sequence control and negative sequence control. The output of positive sequence control is the positive sequence component of modulation wave,which control the voltage amplitude of the PCC point. The output of negative sequence control is the negative sequence component of modulation wave,which balance the voltage drop on the impedance generated by negative sequence current,to make the negative sequence component of PCC point voltage zero. In this way,the PCC voltage will meet the requirements of national standard.Finally,a two-terminal MMC-HVDC system was set up in the platform of MATLAB/Simulink,and the effectiveness of the control strategy is verified.
作者
陆地
李玉
张虎
杨蕊
何欣荣
LU Di1, LI Yu1, ZHANG Hu2 , YANG Rui1, HE Xinrong1(1. Xi＇an University of Architecture and Technology, Xi＇an 710075, China; 2. State Grid Xi＇an Electric Power Supply Company, Shanxi Electric Power Company, Xi＇an 710075, Chin)
出处
《南方电网技术》
北大核心
2018年第2期20-26,共7页
Southern Power System Technology
基金
国家自然科学基金青年科学基金(51407133)~~
