Research On Multi-time Scale Operation Optimization Of Integrated Energy System Considering Uncertainty

With the increasing demand and excessive consumption of fossil energy,the problems of resource exhaustion and environmental pollution become increasingly prominent.The integrated energy system is characterized by multienergy complementary,cascade utilization,high efficiency and flexibility,which is of great importance to the absorption and full utilization of renewable energy.However,the increase of the proportion of renewable energy connected to the integrated energy system will bring about fluctuations during the operation.Therefore,in view of the uncertainty of load demand and the fluctuation of renewable energy output,this paper studies the optimal operation of integrated energy system at multiple time scales based on robust optimization and model prediction control method.On this basis,a low-carbon optimal dispatch model of integrated energy system is constructed by introducing carbon trading mechanism and comprehensive demand response,in order to further develop the low-carbon characteristics of the integrated energy system and achieve the " dual-carbon" goal.The specific research contents are as follows:Firstly,this paper combs the uncertainties of the integrated energy system,multi-time scale optimization problems and model prediction control theory,and the research status of the comprehensive demand response at home and abroad,and constructs the basic framework of the integrated energy system.According to the characteristics of each device,the mathematical models of renewable energy power generation,storage and coupling devices in the integrated energy system are made,which lays a foundation for the later dispatching strategies.Secondly,a day-ahead and intra-day optimal scheduling model based on robust-MPC combination is constructed:in the day-ahead phase,based on robust optimization method,uncertain set is used to describe the range of uncertain factors in the system,and the uncertain parameters are transformed into deterministic linear constraints by ordered truncation.Make day-ahead scheduling more meaningful for tracking and correcting;In the intra-day operation phase,an intraday optimal scheduling model is established with the objective of minimizing the deviation from the pre-day scheduling plan.MPC is used to track and roll-over the pre-day scheduling in real time,and a closed-loop scheduling plan is obtained.The validity of the robust-MPC multi-time scale optimal dispatch model in dealing with source-load fluctuation and improving the economy of system operation is verified by numerical simulation.Finally,in order to further respond to the "carbon dioxide" target and achieve the mutual transfer of multivariate loads in horizontal time and the mutual substitution of vertical output,a comprehensive demand response and carbon trading mechanism are introduced based on the above researches,which enables the electric,thermal and cold loads to participate in demand response.Based on the output and load predictions of renewable energy after demand response,a robust-MPC economic optimal dispatch model based on step-by-step carbon trading mechanism is constructed by studying the free carbon quota model and the actual carbon emission measurement model of energy users in the integrated energy system.Through case simulation,the validity of the model in smoothing the load energy curve is verified to achieve overall energy saving,carbon reduction,cost reduction and efficiency of the integrated energy system.