Research On Optimal Operation Of A Hydropower-photovoltaic-pumped Storage System In The Electricity Market

As the world’s coal,petroleum and other fossil fuel sources are declining,the continual deterioration of human living environment,and countries around the world are strongly supporting the development of renewable energy.As the penetration rate of photovoltaics increases,the abandonment problem becomes more and more serious.Because photovoltaic power generation has the characteristics of randomness,connecting photovoltaic power generation directly to the grid will have a certain impact on the grid.As an important renewable energy in our country,hydropower resources have an important position in the history of energy development in China.Hydropower has the characteristics of fast start-up and stop,and good peak-shaving performance.The participation of hydropower in the peak-shaving operation of the power grid can not only meet the peak-shaving demand of the power grid,but also improve the enthusiasm of the hydropower system.As the most mature and fastest-developing energy storage technology in today’s power grid,pumped storage has become an indispensable part of the development of renewable energy.The paper is supported by the national key research and development program of China “Research and Application Demonstration of Distributed Photovoltaic and Cascade Small Hydropower Complementary Combined Power Generation Technology”(2018YFB0905200).This paper proposes a joint operation strategy of a cascade small hydropower,a pumped storage power station and a photovoltaic power station to participate in the electricity market.The joint operation strategy can not only increase the profits of the photovoltaic power generation and the hydropower in the electricity market,but also effectively address the problem of abandoning solar and water.This paper considers the uncertainties of photovoltaic power outputs,loads,and electricity prices.In the power market environment,the objective function is to maximize the profit of the hydro-photovoltaic-pumped storage joint operation strategy,and a scenario-based stochastic optimization model is established.At the same time,conditional value at risk is taken into account to evaluate the risk of the system.It is worth noting that what this article considers is to meet the local load level before participating in the electricity market.In this paper,the operational problem is transformed into a mixed integer linear programming problem,which is solved by the Gurobi optimization solver in the Python environment.Finally,a case study verifies the feasibility of the proposed joint operation strategy.The results show that when the risk factor is equal to 0,the expected revenue is 15734.1 DKK.As the risk factor increases,the ability of the decision maker to bear risks will gradually decrease.The final results verify the correctness of the proposed model,indicating that the system is economically feasible in the electricity market environment and can bring more economic benefits to investors.Then a cooperative game operation strategy of the hydropower-photovoltaic-pumped storage system in the electricity market is proposed.This study is based on a real system in Xiaojin County,Sichuan province.Although each power station individually participates in the electricity market to obtain higher profits,in fact,the highest profits can be obtained through cooperation.Based on the cooperative game theory,the hydropower-photovoltaic-pumped storage system is studied to participate in the electricity market,and the nucleolus method is used to distribute the profits of the alliance composed of the hydropower-photovoltaic-pumped storage system.The final results show that compared with the independent operation of each power station,the profits of the hydropower station,the photovoltaic power station and the pumped storage power station have increased by 2.67%,79.77% and 106.45%respectively when they cooperate with each other.