Link the simulation with dynamic programming successive approximations to the study on optimal operation chart of cascade reservoirs

Hydroelectric plant operation is based on an operation chart.Most of the existing literatures,however,paid much more attention to the single reservoir chart than cascade reservoirs.In this paper,an approach of working out the optimal operation chart for cascade reservoirs is proposed and applied to the well-developed Wujiang River hydropower system in China.Based on the initial traditional operation charts for single reservoir and cascade reservoirs,power results of each single plant and the cascade system are obtained.Then the load dispatching strategy of cascade reservoirs is adopted to regulate the power variance between the sum power of all the single plants and the power of cascade system.By repeating this procedure,the simulated runoff history is obtained.Finally a dynamic programming successive approximation(DPSA) is used to modify the basic parameters of the two charts at an objective of energy maximizing.In comparison with the traditional effort,this approach can give an integrated optimal operation charts for single reservoirs and cascade system.Simulation results indicate that the proposed approach is valuable and feasible and it significantly improves the power generation benefit under the power grid requirements.