【摘要】 微电网孤岛运行时,储能系统的主要作用是保持母线电压的稳定.针对超级电容储能系统运行时存在的超级电容端电压和母线侧负载的参数变化,导致母线电压发生波动的问题,提出了一种鲁棒LQR控制方法.首先建立变换器的小信号模型;其次选定超级电容端电压和母线侧负载作为不确定量,利用凸优化理论推导储能系统的多胞体模型;最后用线性矩阵不等式(LMI)的方法计算出满足约束条件的LQR控制器.仿真结果表明,当系统存在参数变化甚至外部干扰时,该控制方法能够更快、更好地稳定母线电压,控制效果优于传统的PI控制方法.更多还原

【Abstract】 The main function of the energy storage system is to keep the bus voltage stable when micro-grid is in islanding operation. In view of the change of the system parameters related to super capacitor terminal voltage and bus side load in the operation of the super capacitor energy storage system which causes the fluctuation of bus voltage,a robust LQR control method is presented. Firstly,the small signal model of the converter is established. Secondly,the super capacitor terminal voltage and the bus side load are selected as uncertainties and a multi-cell model of energy storage system is deduced by the theory of convex optimization. Finally,the LQR controller satisfying the constraint condition is calculated by using linear matrix inequality(LMI)method. The simulation results show that the control method proposed in this paper can stabilize the bus voltage faster and better when there are parameter changes or even external disturbances in the system,and that the control effect is superior to the traditional PI control method.更多还原