复杂约束下梯级水电站短期厂网协调多目标MILP模型

随着电力系统负荷的增长及峰谷差的加大,电力消费结构不断优化.电网侧期望水电利用灵活启停特性充分参与电网调峰,以减小系统的峰谷差.电厂侧则在调度过程中追求梯级电量最大,以实现效益最大化.为协调厂网两侧对梯级出力过程的矛盾需求,同时满足厂网两侧复杂的约束条件,以梯级水电站的机组为调度单元,选取梯级发电量最大和电网剩余负荷峰谷差最小为目标函数.充分考虑电网侧联络线约束及电站侧尾水顶托、限制出力曲线、不规则振动区等与水头相关的复杂约束并线性化处理,构建了复杂约束条件下厂网协调多目标短期混合整数线性规划模型,对多目标函数进行归一化处理并采用权重法转化为单目标函数,利用Gurobi商业求解器进行模型求解.中国红水河梯级水电站的实际应用表明所提模型可获得兼顾厂网两侧目标期望的梯级发电计划.

Multi-objective Mixed-integer Linear Programming Model for Short-term Coordination of Power Plants and Power Grid in Cascaded Hydropower Station Under Complex Constraints

With the increase of load and peak-valley difference in power systems, the electric consumption structure is continuously optimized. It is expected that hydropower can use its flexible start-stop feature on the power grid side to fully participate in the peak-shaving of power grid for reducing the peak-valley difference of the system. The power plant side pursues the maximum cascaded electric quantity in the dispatching process to realize the maximum benefit. For the purpose of coordinating the contradictory demands on the cascaded power output process and simultaneously satisfying the complex constraints between the power plant and the power grid, the units of the cascaded hydropower station are taken as the dispatching unit, and the maximum cascaded power generation and the minimum peak-valley difference of the residual load in the power grid are selected as the objective function. The tie-line constraints on the power grid side and the constraints on the power plant side that are related to the water head such as tailwater jacking, output curve limit and irregular vibration areas, are fully considered and linearized. A multi-objective short-term mixed-integer linear programming (MILP) model is constructed under complex constraints to normalize the multi-objective function and transform it into a single objective function by weight method. The model is solved by Gurobi commercial solver.The practical application of the cascaded hydropower plants of Hongshui River in China, shows that the proposed model can get a cascaded generation plan which takes into account the goals and expectations on both sides of the power plant and the power grid.