Research On Optimal Allocation Of Energy Storage Capacity Of Multi-energy Complementary System Considering Wind Power And Photovoltaic Power

As the population of society continues to increase,the demand for fossil energy in various countries is also increasing,and fossil combustion pollution is becoming increasingly serious.China is in a critical period of energy structure transformation,promoting the development of renewable energy and enhancing the proportion of clean energy has become the focus of the development of the energy industry.Among them,there is much research on renewable energy represented by wind and solar energy,and the practical applications of wind power and photovoltaic(PV)power generation are becoming more and more widespread.To improve the economics of stand-alone wind and PV power generation and to reduce the harmful effects of large-scale integration of intermittent energy sources into the grid,complementary wind and solar power generation systems are receiving increasing attention.In addition,the development of energy storage technology is mature,the cost of energy storage is getting lower and lower,and the configuration of reasonable capacity energy storage for complementary power generation systems has become an important way to improve the economy of the system.In this thesis,wind and PV power potential are first evaluated to investigate the potential of wind and solar complementarity for large-scale energy sites based on spatial and temporal characteristics.Then the storage capacity of the system is optimized to increase the safety and reliability of the power system.The main works are:(1)Based on the National Development and Reform Commission’s Renewable Energy Data Book,three calculation methods are used to assess the annual wind power generation potential of each province on an ultra-short-term time scale(15 min),and three indicators,namely the average wind power density,the average annual wind speed and the annual effective wind speed hours,are used to assess the wind resources of each province and to develop a highly reliable potential assessment in time and space.In addition,to further integrate variable PV resources,the PV real-time output of 31 provinces was evaluated using two algorithms by applying the 15-minute light and temperature data in the country measured by the National Development and Reform Commission(2)FR,a volatility index,is proposed to smooth out energy system fluctuations.There is a lack of effective evaluation and matching criteria for the type selection and power feature extraction of filtering methods for the fluctuation smoothing scenario.Four classical filtering methods are used to pre-process the power output data of the integrated energy system and optimize the energy storage capacity of the integrated energy system based on the NSGA-II with the objectives of minimizing the LCC and minimizing the FR.It also quantifies the feed-in security and stability of the integrated energy system by defining coefficients.(3)Finally,considering the economy and safety of the system,the BC is proposed to quickly match the appropriate filtering method and verify its reliability,which provides a reference for the selection of filtering methods for integrated energy systems.After verification by examples,the following conclusions can be drawn:(1)Through the assessment of wind and solar resource potential of energy bases nationwide,some provinces with underestimated energy potential were identified.Through the analysis of energy potential on long-term and short-term time scales,it is found that there are large differences in the daily fluctuations of wind and PV output in different quarters of energy bases in each province,among which the northwest region shows a more excellent spatial and temporal complementary characteristic.(2)The optimal energy storage capacity of the integrated energy system under four filtering conditions is in the same range,which is converted to the POIC of the system,around 5%-30%.Among them,the integrated power amplitude variation,output power delay and fluctuation rate processed by the Butterworth filter,Chebyshev filter and elliptic filter are smaller,more economical and more closely fit the original data of the system.The Bessel-filtered integrated power amplitude variation,output power delay and fluctuation rate are larger,which are the smoothest and safest,but the least consistent with the original data.(3)The reliability of the BC is verified,indicating that the proposed BC can quickly match the optimal filtering method for energy systems considering smoothing fluctuation scenarios,which is universal,reduces the time cost of the modeling process,improves the work efficiency,and has practical significance for the selection of filtering methods.