Quarter-Hourly Operation of Hydropower Reservoirs with Pumped Storage Plants

Abstract

This paper formulates a short-term operation problem to determine the optimal quarter-hourly generation schedules of multiple hydropower reservoirs with pumped-storage plants. The model is a comprehensive one that incorporates the plant-based operating zones (PBOZ), the upper and lower bounds on hydrowide power, the hydraulic coupling, and the requirements for generating power and releasing water with a fluctuation tolerance. A new procedure that includes three key techniques makes the problem easier to solve. First, the original problem is temporally decomposed into several quarter-hourly reservoir operation subproblems by dividing the planning horizon into subhorizons. Second, the plant-based operating zones that are integer variables are separately determined with dynamic programming (DP) after solving an hourly reservoir operation problem, which also derives a target-guiding trajectory for the subproblems. Third, iteratively linearizing the constraints simplifies the problems and having nonlinear objective functions guarantees the convergence of the procedure. As part of the software developed for Wuling Power Cooperation, Ltd., the present model and procedure are practical and efficient in aiding users in operating the reservoirs and scheduling the hydropower generation.