Long-term Scheduling of Cascaded Hydro Energy System with Distributed Water Usage Allocation Constraints

In a hydro energy and water resource system it is desirable to optimize hydropower production with considerations of flood control, residential, agricultural and industrial water supply, navigation, environmental and ecological requirements, etc.. Incorporating complicated constraints of cascaded reservoirs and government regulation on water resource usage allocation, this paper presents a long-term scheduling problem of hydro energy and water resource system based on chance-constrained programming with uncertainties of natural water inflows and water demands of different regions. The water usage regulation with uncertain natural inflow is modeled as probabilistic chance constraints. The nonlinear and noconvex hydro plant production function is converted into mixed integer formulation and a general mixed integer linear programming (MILP) method is applied to solve this complicated scheduling problem. Preliminary numerical testing results for a river basin with cascaded reservoirs show that based on the problem formulation presented in the paper, the long-term scheduling is solved efficiently and accurately. Numerical testing for a more complex hydro system is being conducted.