基于改进模型预测控制的微电网能量管理策略

摘要

微电网中分布式电源出力具有间歇性、波动性等特点,并且负荷形式多样,分布式电源和负荷的不确定性会导致微电网能量优化的不确定性.为了更好地解决上述问题,提出了一种基于改进模型预测控制(MPC)的双层多时间尺度微电网优化策略.传统MPC优化中某些模型参数固定,难以及时处理系统中的突发扰动;并且传统MPC的单个优化周期时长有限,难以处理一些与时间相关或影响优化结果全局性的复杂约束.根据微电网中不确定性因素及复杂约束提出MPC的自适应改进,能更好地适应微电网设备投切灵活、发电功率受外界影响大等特性,更好地保障系统的鲁棒性与优化的精确性.基于日前计划优化出未来的能量分配及负荷调度;在日内基于改进MPC并参考日前优化结果进行实时能量优化,从而使目标更优,提高结果的准确性.最后应用MATLAB进行仿真,证明了所提策略的适用性和准确性.%In a microgrid system,the distributed generator has the characteristics of being intermittent and fluctuating,and the load is variable.The uncertainty of the distributed generator and the load demand will lead to the uncertainty of the microgrid energy optimization results.In order to solve the above problems,an improved model predictive control (MPC) strategy for two-layer microgrid energy optimization with multi time scale is proposed.As some model parameters are fixed in the traditional MPC optimization,it is hard to timely deal with the emergency disturbance in the system;and the single optimization cycle time of traditional MPC is limited,thus it is hard to deal with some complex constraints which are related to time or affect the overall optimization results.An adaptive improved MPC strategy is proposed according to the uncertainty of microgrid and complicated constraints to adapt to the microgrid characteristics of equipment switching flexibility and power generation affected by the outside world.It is shown that the robustness of the system and the accuracy of optimization are guaranteed.The allocation of future energy and load scheduling is optimized according to the day-ahead plan.By taking the results of the day-ahead optimization as reference,the real-time energy optimization is undertaken based on MPC,so as to make the optimization goal better,and improve the accuracy of the results.Finally,the simulation results of MATLAB demonstrate the applicability and accuracy of the proposed method.