基于二次型最优控制的微电网实时能量管理策略

Real-time Energy Management Strategy for Micro-grid Based on the Quadratic Optimal Control Theory

为提高发电经济性和限制电池荷电状态(stateofcharge,SOC)的波动,该文将微电网中功率的动态分配优化控制问题转化成一个扩展的二次型最优控制问题,推导出扩展的二次型最优控制理论的最优解。应用黎卡提方程和伴随方程解的性质,在一定假设条件下,得到近似的最优解,进而得到可用于实时控制的能量管理策略。仿真结果显示,所提策略的发电成本与离线最优策略的优化结果十分接近,同时该策略可将电池组SOC控制在给定参考值附近以防止其过充或过放。

To improve the power generation efficiency and to limit the fluctuation of the battery state of charge(SOC), this paper formulated the energy distribution optimization problem of the micro-grid as an extended quadratic optimal control problem, and the optimal solution of the extended quadratic optimal control theory was derived. By using the solution properties of the Riccati and adjoint equation, the approximated optimal solution under some specific assumptions, which is easy to be real-time implemented, was obtained. Simulation results show that the generation cost of the proposed strategy is very close to that of the optimal offline algorithm, and the battery SOC fluctuating around the reference value to prevent the battery overcharge or over discharge.