Research On Unit Commitment Optimization With Accounting For Renewable Energy Into Reserve Of Power System

Recently,vigorous exploitation and utilization of renewable energy to achieve clean energy substitution have become an important development policy for countries around the world to handle energy shortages and the deterioration of the environment.As the most mature green power,the scale of wind power integration in the power system continues to expand,and wind power with high penetration will become the basic features of China’s power grid.The research on reasonable reserve demand and dispatch strategy for the uncertainty of wind power could not only improve the operation economy but also increase the consumption of wind power.Based on this,this thesis focuses on the unit commitment problem with accounting for renewable energy into the reserve of power system.To more accurately characterize the uncertainty of wind powe r,a fitting method based on the time series features of load fluctuations is designed,and the versatile distribution model is used to characterize the probability of forecast error.The example results show that the fitting method can more refine the pro bability distribution of wind power forecast errors,thus reserving a reasonable reserve capacity for the system.Based on the theoretical analysis of the impact of renewable energy into the system reserve on operation,a layered optimization model for un it commitment considering renewable energy into the reserve is proposed.The upper-level model adopts the reserve operation method that takes into account the renewable reserve,and the output of the pumped storage and the reserve capacity of the wind power is calculated by taking the smooth residual load demand curve.The lower-level model is based on the optimization results of the upper,and comprehensively considers system operating costs and pollutant gas emissions,and then optimizes the windthermal-storage system.Among them,chance constraint theory is used to characterize the impact of wind power uncertainty on the system.Then,case results suggest that the schedule considering the economy and environment of the system can be formulated,and the consumption of renewable energy is also improved,which has certain practical significance.A global rolling dispatch model is established that considers the integration of renewable energy into the power system reserve based on the update of wind forecast information and the change of forecast errors.According to the variation characteristics of wind forecast error decreasing with the shortening of forecast lead time,a global rolling mechanism of schedule based on the update of wind power forecast information is designed.Then,the rolling optimization model based on the renewable energy into the system reserve is established,and the chance constraint theory is used to handle the uncertainty of wind power.During the optimization process,the capacity of the renewable energy integrated into the reserve changes with the update of the wind power forecast information.Finally,numerical results from case analysis show that the proposed model can coordinate the schedule of different time scales based on the rolling update wind power forecast information,and then obtain the global economic optimal schedule.