| The development of renewable energy is one of the important measures to achieve the goal of " carbon peak and carbon neutrality." In the past decade,China ’s renewable energy has developed rapidly.Taking wind power as an example,by the end of 2022,China ’s wind power will increase by 37.63 million kilowatts in 2021,and the cumulative installed capacity has reached 365 million kilowatts.However,due to the strong volatility,intermittence and uncertainty of renewable energy output such as wind power,and with the large number of renewable energy connected to the grid,the regulation ability of the power supply side is weakened,resulting in serious wind and light abandonment in some areas of China.Driven by the dual carbon target in the future,the proportion of renewable energy integration will still increase,and the regulation ability of power system operation will be greatly challenged,which puts forward higher requirements for the flexibility of power system.In China ’s power structure,thermal power installed capacity is dominant,through the transformation of thermal power units to improve the flexibility of the way to achieve renewable energy consumption is still the main choice of the grid.However,with the gradual increase of the proportion of renewable energy grid connection,the output space of thermal power units is gradually occupied,resulting in damage of the interests of thermal power producers and low enthusiasm of participating in peak regulation.The introduction of peak regulation auxiliary service mechanism of thermal power units is conducive to providing their enthusiasm for participating in deep peak regulation.In addition,as a high-quality flexible resource,energy storage has the characteristics of fast response speed and flexible installation location,but it has the problems of high cost and imperfect revenue accounting mechanism.In summary,the research on the source-storage-network coordinated planning method considering the comprehensive income of flexible resources is conducive to the allocation of flexible resources and the improvement of their enthusiasm for participating in peak shaving,which can further improve the supply and demand balance of proportional new energy grid-connected,and is of great significance in promoting the realization of the ’ dual carbon goal ’.In this paper,facing the demand for safe and economic operation of power systems with a high proportion of renewable energy sources on the grid in the future,a series of methods are carried out to address the problems of inadequate accounting mechanism for energy storage resources and limited peak regulation capacity of a single flexible resource,including analysis of the mechanism of participation of flexible resources in the auxiliary service market,research on the joint source-storage-transmission planning method that takes into account the comprehensive income of energy storage,and research on the flexible transformation of energy storage and thermal power units considering the income of auxiliary services.A series of methods such as coordinated planning methods have been developed to maximize the comprehensive system revenue based on improving the peaking capacity of flexible resources and the system’s ability to accept possible renewable energy when a high percentage of renewable energy is connected to the grid in the future.The main work of this thesis is as follows:Mechanistic analysis of the participation of flexibility resources in the ancillary services market.This chapter analyses the mechanism of deep peaking of thermal power units and energy storage systems respectively,establishes mathematical models for the two types of flexibility resources,and analyses the economics of participation in the ancillary services market.In addition,considering the impact of fixed time-sharing tariffs on the revenue of energy storage,two dynamic time-sharing tariff formulation methods are proposed,and the relevant parameters of energy storage after peak shaving and valley filling with different tariff rules under different penetration rates are explored to verify the effectiveness of dynamic time-sharing tariffs,while laying the theoretical research for the subsequent planning studies.A joint source-storage-transmission planning approach that takes into account the comprehensive benefits of energy storage is proposed to address the problems of high costs and inadequate revenue accounting mechanisms.Firstly,the source-storage-transmission coordinated optimization model considering the comprehensive benefits of energy storage is based on the perspective of maximum benefits of energy storage,the positive impact on the power system after the deployment of energy storage,the direct benefits generated by peak-valley arbitrage and the indirect benefits such as reduced investment costs of power units,reduced investment costs of grid transmission lines,reduced abandoned wind penalty costs and reduced system network loss costs of the power system before and after the deployment of energy storage are incorporated into the optimization objective.A joint source-storage-grid planning model considering the comprehensive benefits is constructed by incorporating the optimization objectives;then,the solution ideas and solution steps of the model are given;finally,the effectiveness and economy of the method are verified through the simulation analysis of the example system.In response to the difficulty of balancing the relationship between system economics and peaking performance by simple thermal unit retrofit or optimal allocation of energy storage,a coordinated planning method for energy storage and thermal unit flexibility retrofit that considers the revenue of auxiliary services is proposed.First,the method uses energy storage and thermal power unit flexibility retrofit to enhance the system peaking capacity,takes into account the revenue indicators and system cost indicators of system operation proposed in the second chapter,and constructs a source-storage planning model considering the comprehensive income and wind curtailment rate of the system;then,the solution ideas and solution steps of the model are given;finally,through the simulation of the actual engineering system,a source-storage planning scheme that takes into account the system economy and wind power acceptance capacity is obtained.Finally,through the simulation of the actual engineering system,the source-storage planning scheme is obtained,which solves the problem of balancing the economy and wind abandonment rate in the high wind power penetration system;meanwhile,on this basis,the influence of the dynamic time-sharing tariff mechanism on the use of energy storage and thermal power unit flexibility modification to improve the system peaking capacity is investigated,and it is verified that the dynamic peak-valley tariff can better balance the system economy and wind abandonment rate while improving the system’s ability to accept wind power. |
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