摘要
模块化多电平换流器(MMC)是高压直流输电领域最具发展前景的拓扑结构之一。针对MMC经典控制理论过于依赖模型精度,控制器参数整定复杂,以及MMC传统模型预测控制(MPC)方法中计算量过大、控制精度不足等问题,本文提出一种循环寻优的模型预测控制算法,对多个控制目标逐级优化实现追踪交流电流、抑制相间环流、平衡子模块电容电压和优化开关频率,该算法在考虑提高运行效率的同时,还兼顾了良好的控制效果。在Matlab/Simulink环境下搭建了背靠背MMC-HVDC系统并进行仿真。结果表明,所提控制策略将计算量降低了99.97%,且提高了控制目标精度,特别是桥臂子模块数增多时效果更好,符合工程应用中电压等级高、输送容量大等特点,适用于MMC灵活可拓展特性。与传统MPC方法相比,该控制策略实用性更强。
Modular Multilevel Converter（ MMC） is one of the most promising topologies in HVDC system. For traditional control theory of MMC excessively relying on accuracy of model and complex parameters tuning,as well as an amount of computation and lacking of accuracy in MMC traditional model predictive control（ MPC）,an improved MPC algorithm based on loop optimization is proposed,in which by optimizing multiple objectives,tracking AC current,suppressing circulating current,balancing SM voltage and optimizing switching frequency are achieved.The algorithm takes the good control effect into account and improves operation efficiency. A back-to-back MMCHVDC system model is established in the Matlab/Simulink environment,and the results show that the proposed strategy can reduce 99. 97% of the calculation work and improve the precision,and the effect is better with the increase of the numbers of SM especially. The new method is suitable for the characteristics of high voltage and large conveying capacity of application,and it is applicable to MMC flexible expansion characteristics. Compared with traditional MPC method,the proposed strategy is more practical.
出处
《电工电能新技术》
CSCD
北大核心
2018年第2期9-18,共10页
Advanced Technology of Electrical Engineering and Energy
基金
国家自然科学基金项目(51507029)
关键词
模块化多电平换流器
模型预测控制
环流抑制
电容电压平衡
循环寻优
modular multilevel converter
model predictive control
circulating current suppression
capacitor voltage balance
loop optimization
