The Research On Dynamic Random Optimal Control Of Cascade Reservoir Scheduling

During the joint operation of many reservoirs, the pursuit of the biggest overall efficiency is a complex dynamic random optimal control problem, which is not only to solve the problem of flow scheduling between the reservoirs, but also to achieve optimal economic operation of the hydropower station. In this article, the background is of the two cascade reservoirs (one is upper and one is lower) joint operation. The random characteristics and the dynamic time-varying characteristic of many factors are considered, and the optimum scheduling decisions are given by dynamic random optimal control theory and method. The generalization of this model is more realistic, and the model calculation is strictly in accordance with mathematical theory. In view of these goals, the following contents are researched.First, the physical background of this article is introduced in detail, including the basic operational mode and operational characteristics of reservoirs, which is used to explain that the reservoirs' joint operation involving flow scheduling balance, the selection of power flow and hydraulic units with many dynamic parameters is a complex dynamic random optimal control problem. Then the factors (runoff, reservoir water level, storage, etc.) will affect the efficiency, which are considered as the random process, making the generalization of the project more realistic.Second, runoff is estimated with maximum likelihood estimation method, and the best water level downstream model and the largest power generating efficiency of optimal reservoir scheduling model are established with the estimated model.Third, based on the theoretical analysis and physical background of reservoir scheduling, the objective function and constraints are determined, then the nonlinear best water level model and the nonlinear largest power generating efficiency model are solved. The variation of functional extremeness value method is used to solve the best water level downstream, which is used to determine the laying order of the two reservoirs and the optimal discharge of the upper reservoir. Also, the function extremes principle is used for solving the flow distribution of the hydraulic units with inequality constraints to achieve the random optimal control of economic operation of the inner plant.Finally, one pair of cascade reservoir scheduling problem selected as an example, the practical solution is introduced by random optimal control theory and method.