基于改进MPC的混合储能系统控制策略

Control strategy of hybrid energy storage system based on improved MPC

当直流微电网母线功率发生波动时,混合储能系统能有效维持母线电压的稳定。混合储能系统控制策略通常采用基于PI控制的双闭环控制算法。但由于内环PI调节的滞后性,会出现动态响应速度不佳的问题。提出了一种基于多步预测的模型预测控制(MPC)混合储能系统双闭环优化控制策略,多步预测MPC可降低传统MPC的预测误差,将改进后的MPC作为控制内环来解决传统双闭环控制内环动态响应速度不佳的问题。实验结果表明,与传统MPC作为内环的双闭环相比,优化控制策略减小了系统超调量,与基于PI的传统双闭环控制相比,提高了混合储能系统的动态响应速度,使母线电压突变时电压的恢复时间减少了51%,验证了双闭环优化控制策略的有效性。

When the bus power of the DC microgrid fluctuates,the hybrid energy storage system(HESS)can effectively maintain the stability of the bus voltage.The HESS control strategy usually utilizes a double closed-loop control algorithm based on PI control.Due to the hysteresis of the inner loop PI regulation,there is a problem of poor dynamic response speed.A HESS double closed-loop optimization control strategy based on multi-step prediction MPC was proposed.The multi-step prediction MPC could reduce the prediction error of traditional MPC,and the improved MPC was used as the inner loop to solve the problem of poor dynamic response speed of the inner loop of the traditional double closed-loop control.The results show that compared with the traditional MPC double closedloop control,the optimized control strategy reduces the overshoot of the system.Compared with the traditional double closed-loop control based on PI,the optimized control strategy improves the dynamic response speed of the hybrid energy storage system and reduces the voltage recovery time by 51%when the bus voltage changes abruptly,verifying the effectiveness of the double closed-loop optimization control strategy.