Photovoltaic Capacity Optimization Of Hydro-photovoltaic Hybrid Energy Systems Based On Joint Optimization Operation

The development and utilization of renewable energy is an important way to ensure future energy security and deal with global climate change.Among them,photovoltaic power generation because of its characteristics as a green pollution-free renewable energy,technology increasingly mature,low cost,and more and more popular.Under normal circumstances,the capacity of photovoltaic power plant is determined based on investment and benefit.However,due to the inherent uncontrollable power generation characteristics of photovoltaic power generation,there is a lack of controllable power to regulate it in the power grid,and direct incorporation into the power grid will lead to the problem of "absorption".Therefore,this paper takes advantage of the flexible output characteristics of hydropower stations and considers the optimization of installed capacity of photovoltaic power stations from the perspective of optimal operation of hydro-photovoltaic hybrid energy system,to provide technical support for the planning and design of photovoltaic power stations.The main work and results of this paper are as follows:(1)Based on the analysis of different output characteristics of hydropower plant and photovoltaic power plant and their respective influencing factors,the uncertainties coupling model of hydro-photovoltaic hybrid energy systems was established by coupling the inflow runoff frequency of hydropower plant and the standardized typical output of photovoltaic power plant.Taking the Naijili hydro-photovoltaic hybrid energy system project in Qinghai Province as the research example,20 scenarios covering extreme climate were set,and the uncertainty quantitative model of hydrophotovoltaic hybrid energy system was used to carry out scenario probability calculation,which laid a theoretical foundation for setting the optimal scenario of photovoltaic power station capacity in the following paper.(2)A two-layer nested model for capacity optimization of photovoltaic power station under basic load mode is established.The maximum uniform output of the system was taken as the objective function to optimize the photovoltaic capacity in a specific situation,and then the capacity was determined by the confidence degree of the scenarios and probabilities calculated by the uncertainty quantitative model of the hydro-photovoltaic hybrid energy system.Taking the Naijili hydro-photovoltaic hybrid energy system project in Qinghai Province as an example,the relationship curve of photovoltaic capacity and confidence is drawn.The results show that when the confidence is 85%,the corresponding photovoltaic capacity is 6MW,and the installed capacity ratio of photovoltaic power station and hydropower station is 6:16.The rationality test is carried out to verify the effectiveness of the model.(3)A two-layer nested model for capacity optimization of photovoltaic power plant under peak-shaving mode is established.Taking the maximum peak-shaving regulation capacity of the system as the objective function,the photovoltaic capacity in a specific situation was optimized,and then the capacity was determined by confidence degree based on the scenarios and probabilities calculated by the uncertainty quantitative model of hydro-photovoltaic hybrid energy system.Taking the Naijili hydro-photovoltaic hybrid energy system project in Qinghai Province as an example,the relationship curve of photovoltaic capacity and confidence is drawn.The results show that when the confidence is 85%,the corresponding photovoltaic capacity is7 MW,and the installed capacity ratio of photovoltaic power station to hydropower station is 7:16.The rationality test is carried out to verify the validity of the model.