模块化多电平换流器的快速电压模型预测控制策略

Fast Voltage Model Predictive Control Strategy for Modular Multilevel Converters

针对传统模型预测控制策略用于模块化多电平换流器(MMC)时存在运算量庞大的问题,在分析MMC离散数学模型的基础上,通过优化控制目标实现方式、简化滚动优化过程,提出一种结合排序均压思想的快速电压模型预测控制策略。该控制策略针对三相MMC系统,基于电压矢量预测模型进行设计,可在保留传统模型预测控制算法优点的同时令运算量得到大幅度减小,使其应用不受MMC电平数量限制。通过在MATLAB/Simulink软件中搭建双端21电平的基于MMC的柔性高压直流输电(MMC-HVDC)系统模型进行了仿真验证,证明了所提控制策略的正确性和有效性。

Conventional model predictive control （MPC） strategies for the modular multilevel converter （MMC） are not ideal for actual applications because of the tremendous calculation burden. To solve this problem, a fast voltage MPC （FVMPC） strategy is proposed based on a discrete mathematical voltage vector model of the MMC derived in this paper. By optimizing the implementation of the control targets and simplifying the rolling optimization, the proposed algorithm makes it simpler to expand to higher voltage levels for the three-phase MMC, with the burden of calculation significantly reduced and the advantage of the conventional MPC algorithm retained. The feasibility and effectiveness of the proposed strategy are verified by simulation results of a 21-level back-to back MMC based high voltage direct current system using the simulation software MATLAB/ Simulink.