Research On Optimal Scheduling Method Of Cascade Hydropower Stations Under The Monthly Power Market

With the development of power market in China,the cascade hydropower dispatching method has also changed,from centralized scheduling by dispatching centers to self-scheduling by the cascading power generation stations with market regulation based on their own benefits,from participating in a single type of power market to participating in multiple power markets at the same time,which on the one hand promoted the competitions between the market players,improved the efficiency of the power industry,and increased social welfare,but on the other hand,it also raised the problem of how does the cascade hydropower make optimal decisions in the new market environment to achieve optimal allocation of water resources.The dual constraints of time and space caused by the hydraulic connection between the cascade hydropower stations and the nonlinearity of the hydropower station’s generation function further exacerbate the challenge.Aiming at the optimal dispatching problem of cascade hydropower under the monthly electricity market,this paper took the Yunnan power market as the background and the Lancang River cascade power stations as research instances,studied the optimal dispatching method of multiple cascade hydropower plants in non-transferable utility cooperative games and the optimal dispatching method of cascade hydropower stations under multiple power market based on improved branch and bound algorithm.We draw the following conclusions:(1)Aiming at the problem of optimal dispatching method of multiple cascade hydropower plants in non-transferable utility cooperative games,this paper constructed a multi-agent noncooperative game model and a non-transferable utility cooperative game model under the monthly matched trading market,and solved the models by the genetic algorithm framework.Finally,based on the Yunnan monthly matched trading market and the Lancang River cascade power stations,the simulation experiments were carried out in four scenarios respectively,and the effects of factors such as upstream or downstream,different regulation performances,and different demand situations on the generation decisions of cascade hydropower stations owned by multi-stakeholders in the power market were analyzed through the comparison of the results.Meanwhile,we proved that the cooperative game model can reduce the electricity price while increasing the revenue of the cascade power stations.The model proposed in this paper can provide help for cascaded hydropower stations owned by multi-stakeholders to optimize their power generation decisions in the power market.(2)Aiming at the problem of optimal dispatching method of cascade hydropower stations in multiple power market,this paper taking the market framework coupled monthly energy market and contract transfer market as the representation of multiple power market,constructed the optimal dispatching model of cascade hydropower stations in multiple power market,proposed an improved branch and bound algorithm to solve the model in consideration of its non-convex nonlinear characteristic.Finally,a series of numerical experiments were carried out under the background of the Yunnan power market and the Lancang River cascade power stations.The experimental results showed that the method and model proposed in this paper can effectively guide the hydropower companies to obtain greater profits and promote the optimal allocation of resources.Meanwhile,the experimental results revealed the effect of electricity price on guiding final water level control,and then,provided decision support for market organizers to control electricity price.