基于LQIR的MMC-SST输入级控制策略研究

Research on MMC-SST input stage control strategy based on LQIR

针对现有固态变压器(Solid-State Transformer,SST)输入级控制算法复杂,且参数整定困难等不足,文章提出一种基于线性二次型积分调节(Linear Quadratic Integrate Regulator,LQIR)的最优控制策略。首先根据固态变压器输入级的简化等效电路建立了基于dq旋转坐标系的数学模型;然后,推导了换流器交、直流侧的状态空间方程,并提出了基于LQIR控制器的新型综合控制策略;最后,在Matlab/Simulink中搭建基于模块化多电平变换器(Modular Multilevel Converter,MMC)型SST的仿真模型,并与传统比例积分(Proportion Integration,PI)控制进行对比,在几种典型测试工况下验证了所提控制策略的可行性与优越性。

In view of the shortcomings of the Solid-State Transformer(SST),such as the complexity of input stage control algorithm and the difficulty of multi-parameter tuning in engineering practice,In this paper,an optimal control strategy based on Linear Quadratic Integration Regulator(LQIR)is proposed.Firstly,a mathematical model based on dq rotating coordinate system is established according to the simplified equivalent circuit of solid-state transformer input stage.Secondly,the state space equations of the AC and DC sides of the converter are derived,and a new integrated control strategy based on LQIR controller is proposed.Finally,the simulation model of Modular Multilevel Converter(MMC)SST is built in Matlab/Simulink.And compared with the traditional Proportion Integration(PI)control,the feasibility and superiority of the proposed control strategy are verified under several typical test conditions.