Short-Term Scheduling for Large-Scale Cascaded Hydropower Systems with Multivibration Zones of High Head

Abstract

Construction of huge hydropower plants in the southern region of China has been rapidly increasing in recent years. These plants usually have multiple vibration zones of high head that have a great effect on short-term scheduling and real-time operations. This paper presents a novel approach for optimizing short-term scheduling of large-scale cascaded hydropower systems with multivibration zones of high head. For the purpose of cutting down peak loads, standard deviation minimization relevant to the remaining load series for thermal systems was chosen as the objective nonlinear function. Before the optimization, unit forbidden operation zones were identified by assembled mathematical techniques and hydro unit commitments were optimized using dynamic programming. The combined sets of forbidden operation zones and hydro unit commitments were repeatedly used during the search process. An optimization framework that combined the progressive optimality algorithm with a vibration zone avoidance strategy was finally presented to solve the short-term hydropower scheduling problem. The proposed methodology was applied to a case study in China and the results obtained indicate that it is able to not only handle complex constraints of multivibration zones, but also provide efficient and feasible solutions for short-term scheduling of large plants.