Optimal hydro generation and interchange scheduling with flow-dependent channel constraints

This paper describes the mathematical formulation, algorithm and some sample results of the advanced short-term hydroelectric generation scheduling function that has been developed as part of a new energy management system. An approach to consider nonlinear, noncontinuous constraints in linear optimization problems, is presented in this paper. The hydroelectric generation and interchange is scheduled to maximize the profit from buying and selling energy while meeting these hydro operating constraints. This problem has been successfully solved for up to a 168 hour time frame using mixed integer linear programming (MILP). This method is well suited to solving this optimization problem with the complete set of hydro constraints, including the flow dependent ramp limits. This paper includes some details of results obtained for some actual operational scenarios, where it can be clearly demonstrated that the new algorithm produces hydro and interchange schedules which maximize the generation over the heavy load hours (in which the energy can be sold at a higher price) and minimize generation over the light load hours while meeting all constraints on the hydro system.