Proportional Allocation Method Of Wind Power And Photovoltaic Capacity Based On Minimizing Cost Of Flexible Resource In Power System

With the release of the White Paper "China’s Energy Development in the New Era" and the proposal of the goal of "carbon peak and carbon neutral",it has become an inevitable trend to promote the construction of renewable energy such as wind power and photovoltaic power during the 14th Five-Year Plan period.Large-scale renewable energy access to the grid will bring flexibility requirements to the power system.In the context of ensuring the consumption of renewable energy and ensuring the reliable operation of the power system,it is necessary to install flexible resources,which means that the further development of renewable energy is closely related to the development of flexible resources.In the process of the development of renewable energy,the output characteristics of renewable energy with different wind power and photoelectric capacity ratios are different,so are the corresponding flexibility demands.If the flexibility constraints of the system are taken into account.the corresponding flexibility resource construction costs are also different.Therefore,the technical and economic analysis of flexible resources and the proportional allocation study of wind power and photovoltaic capacity are of great significance.In this dissertation,the technical and economic characteristics of flexible resources,the evaluation of system flexibility and the proportional allocation of wind power and photovoltaic capacity are deeply studied.The specific research contents are as follows:Based on the literature review of definition of power system flexibility,supply and demand analysis of flexible resources,flexibility quantitative evaluation method and proportional allocation model of wind power and photovoltaic power generation capacity,the technical characteristics of the existing flexibility resources in the power system of source,network,load and storage and their technical suitability for different flexibility requirements are investigated and compared.On this basis,the full cycle kilowatt-hour cost estimation model is established under the condition of flexible resources provided by power supply and energy storage.The climbing and peak-adjusting scenarios of power supply and energy storage are designed,and the economic ranking of flexibility resources is conducted respectively.In view of the most urgent demand for peak-shaving in China,this dissertation establishes a multi-dimensional economic evaluation model to score the economic characteristics of flexible resources suitable for peak-shaving technology,and calculates the cost of promoting the consumption of 1kWh renewable energy under different continuous peak-shaving time scenarios in a day,to analyze the economics of flexible resources further.The limitations of the traditional reliability index evaluation of the power system with a high proportion of renewable energy have been analyzed,and the flexibility evaluation index that is suitable for high-proportion renewable energy systems and can be used as an effective supplement to reliability has been investigated.Based on the in-depth disassembly of the lack of flexibility indicator system proposed in the existing research,four evaluation indicators including loss of ramping flexibility probability,loss of ramping flexibility expectation,loss of peak-shaving flexibility probability,and loss of peak-shaving flexibility expectation,which are helpful to guide the construction of flexibility resources,are put forward in a targeted manner.And the calculation method of these flexibility evaluation indicators has been clarified.Relying on the technical and economic analysis of flexible resources,the flexible resource construction plan was designed,and taking the proposed flexibility evaluation index as constraints,a proportional allocation method of wind power and photovoltaic capacity based on minimizing construction cost of flexible resource in power system is proposed.The effectiveness of the method is verified through calculation examples.With the adjustment of the proportion of wind power and photovoltaic capacity under a certain total renewable energy capacity,changes in system flexibility evaluation indicators,system abandonment of wind power and photovoltaic power generation rate,and the construction cost of flexible resources that need to be additionally installed to meet flexibility evaluation index constraints have been thoroughly analyzed.