Research On Multi-objective Optimal Dispatching Of Cascade Hydropower Stations Under The Coordination Of Plants And Grid

Water resource is the dominant resources of our country,it occupies an important strategic position in the national economy.Thus,developing the water resource is the important measures to guarantee the sustainable development of economy of our country.Large water conservancy hub usually perform a variety of scheduling tasks,such as flood control,power generation,peak shaving,and water supply etc.While various scheduling goal often restrict and conflict with each other,it needs to balance the scheduling goal.The quality of the result decision will directly affect the reservoir generation benefit and network security,which also reflected the practical problems faced by water conservancy hub for comprehensive benefits.The goal of the existing power generation model is to ensure the maximum power output,the maximum load power generation and the largest peak power etc.Among them,the demand of the power grid is to ensure the output and peak load as much as possible,while the power station will seek to maximize the benefit of power generation.When building a multi-objective optimization model for reservoirs,these goals are generally combined in a model according to the requirements of actual dispatch,which includes the goal of the power grid and power station.Taking the maximum load power and largest power generation model as example,when we increase the power plant in the dry season to ensure that the output,power generation capacity will be reduced and the power generation efficiency will be influenced as a result.Thus,there is a conflict of interest between the power plant and the power grid.Therefore,it is necessary to consider the power generation capacity of the power station and the absorptive capacity of the power grid system,in which we should reasonably coordinate the contradiction between the power grid and the power station under the premise of safe operation of the power grid.Based on the above analysis,this thesis establishes a multi-objective power generation optimal dispatching model for cascade reservoirs under the network-network coordination model.in which the two important optimization indicators,power generation and assurance are coordinated by electricity and capacity to meet the needs of the plant and the grid.This thesis proposes a method to optimize the weight coefficient to coordinate the power generation and guarantee the output of the power station with the help of the power price of the power supply and the capacity power price.This method simplifies the solving process for the weight coefficient by getting the ratio of the two prices.Furthermore,this thesis select a reasonable power price to choose the best one from all the alternative scheduling programs for meeting the different requirements of power grid in different period,which pursues total benefits of the two goals.In the end,the method is applied to the long-term optimal scheduling of cascade hydropower stations in Lishui,Hunan Province.The example analysis verifies the validity and excellence of the model and method.