Study On Capacity Allocation And Coordinated Operation Of Large-scale Hybrid System Considering The Uncertainties

Hydropower is utilized to compensate for the fluctuations caused by wind power and photovoltaic(PV)in the synergistic exploitation of hydro,wind power,and PV,which is an effective way to enhance the quality of grid-connected power and the operation stability of the grid.With the extensive centralized exploitation of hydro-wind-PV hybrid complementary system,the uncertain fluctuations of wind and PV output undermine the coordination of the hybrid system,and also has an adverse impact on the consumption of wind power and PV.Considering the complementary characteristics of hydro,wind power,and PV,it is the main issue to reasonably configure the capacity allocation scheme at the planning level,and explore the coordinated operation mode of the hydro-wind-PV multi-energy complementary system.Regarding the above issues,this study has carried out research on the capacity configuration and coordinated operation optimization of the hydro-wind-PV multi-energy complementary system considering energy uncertainty and hydropower regulation capabilities.The study method of wind and PV power output uncertainty are proposed,and a nested model of capacity configuration and coordinated operation optimization is constructed.Finally,the upper Yellow River hydro-wind-PV hybrid system is taken as an instance to verify the effectiveness of the proposed method and model.The details of the primary research are as follows:(1)The research on wind and PV power output uncertainty is carried out.A sampling-based scenario generation method is proposed to characterize the uncertainty of wind power and photovoltaics.The Copula theory is used to construct the joint distribution model of the wind power and PV output.The Latin cube sampling method is used to sample according to the joint probability distribution function.The joint wind-PV scenarios are generated based on the fluctuation characteristics of wind power and PV.And the K-means algorithm based on dimensionality reduction is used to reduce the scenario collection.Finally,the uncertainty research method is applied to the upper reaches of the Yellow River hydro-wind-PV multi-energy complementary system.The results verify that joint wind-PV scenarios have obvious seasonality.(2)The research on the large-scale hydro-wind-PV multi-energy complementary system capacity configuration nested coordinated operation optimization model research is carried out.A two-stage self-adaptive complementary strategy for the complementary system is proposed.Based on this,a capacity configuration model with the goal of the maximizing the wind and PV penetration rate and minimizing the system output fluctuation is constructed,nesting a cooperative operation optimization model with the goal of minimizing the variation coefficient of hydropower output.Finally,a three-layer nested framework is proposed to solve the problem of capacity allocation and collaborative operation optimization.(3)The application research of the capacity configuration nested coordinated operation optimization model of the Yellow River hydro-wind-PV multi-energy complementary system is carried out.The results show that the optimal complementary wind and PV capacities of the Laxiwa hydropower station are2800 MW and 1400 MW,respectively.The results of system coordinated operation in each scenario reveal the impact mechanism of wind power and PV uncertainty on the complementary operation.And it is verified that the proposed complementary strategy can effectively enhance the stability of the system output.Finally,the role of complementary systems in the power grid is evaluated,and the influence of capacity configuration on complementary characteristics is further analyzed.