Study On The Comprehensive Impact Of Coal Power Flexibility Transformation On The System Based On Economic Dispatch Model

Under the influence of double carbon target and high quality and sustainable development,building a new power system with new energy as the mainstay has become an inevitable trend of power development.However,the power output of wind and solar units is highly volatile and random,and their high proportion of grid connection will bring serious challenges to the safe operation and economic dispatch of the power system,while the power system flexibility resources are insufficient,and the process of low-carbon transformation of the power system will be seriously hindered.Coal power units with large inventory and mature technology can enhance the flexible regulation ability of power system after flexibility transformation,and can promote new energy consumption when participating in system economic dispatching,and help to build a new power system.Therefore,based on the time-series production simulation model,this paper conducts qualitative and quantitative analyses on the impact of coal power flexibility transformation before and after and different transformation scales on the system economic dispatching results in provincial power grids against the background of continuous development of new energy units,and selects Shandong Province power system as a real case study to clarify the benefits of coal power flexibility transformation to help the low-carbon transformation of provincial power systems and provide a scientific basis for the coal power flexibility transformation path.This paper first summarizes the current situation and experience of coal power flexibility transformation at home and abroad,analyzes the current domestic coal power flexibility transformation process and transformation bottlenecks.It also summarizes and analyzes the changes of key technical indicators of unit operation before and after the transformation.Second,a qualitative analysis is carried out on the impact of coal power flexibility transformation on system economic dispatch.The points of benefits that coal power flexibility transformation can bring to system economic dispatch are analyzed from three perspectives:the impact on coal power units themselves,the impact on system power side and load side,and the impact on high percentage renewable energy systems.The analysis concludes that,in the short term,coal power can effectively consume wind and solar power by participating in economic dispatch after the transformation,but in the high proportion renewable energy system,the flexible adjustment space released after the transformation cannot meet the demand for grid-connected consumption of high proportion new energy installations due to the limited capacity of coal power units in stock,and the system still faces a serious problem of consumption.Then,a timeseries production simulation model considering renewable energy access is introduced,and Shandong province is selected as a practical case for analysis.Based on the current power development status and coal power flexibility transformation scale in Shandong Province,12 provincial power system development scenarios are constructed,and the scenarios are simulated with the time-series production simulation model for system economic dispatch.Finally,based on the simulation results,the impact of different flexibility transformation scales of coal power on the system economic dispatch is quantitatively analyzed.The results show that the system low-carbon transition mainly relies on the structural changes on the power supply side,but coal power can also optimize the generation structure and reduce the system generation cost and carbon emission when it participates in the system economic dispatch after the flexibility transformation.As the scale of coal power flexibility transformation increases,the gaining effect of its favorable impact on system economic dispatch will gradually weaken,however,the larger the transformation scale is,the more favorable it is to system economic dispatch.In the high proportion of renewable energy power system,the impact effect of flexibility transformation is more obvious,but it is not enough to improve the system flexible regulation capacity by coal power flexibility transformation alone,and it is still necessary to increase the investment in other flexibility resources to promote the synergistic development of source,network,load and storage flexibility to ensure the safety of power system transformation.