Research On Multi-temporal And Spatial-scale Operation Optimization Of Distributed Energy System

Combined Cooling,Heating and Power system(CCHP)has the excellences of high energy utilization efficiency,reliable energy supply and low pollution,and has been widely used in various energy supply fields.Currently,with the large-scale application of renewable energy and energy storage systems in CCHP systems,the degree of coupling between various energies is more complex and variable,resulting in an increase in the deviation between source-load and large power fluctuations of the equipments.In this paper,taking the CCHP system belonging to different types of communities as the research object,the particularities of the device within the system are determined,the mathematical model of the device is established,and the multi-time scale operation optimization strategy is proposed.And the output fluctuation of the equipment is continuously reduced through step-by-step optimization,and finally the safe,economical and stable operation is achieved.The CCHP system structure containing energy storage system is established,and the capacities of the varous equipments in the corresponding system are optimized.With the primary energy saving rate(PESR),emission of pollutant saving rate(EPSR)and annual total cost rate(ATCR)as the optimization goals,the multi-target genetic algorithm(NSGA-II)is used to determine the equipments capacities in the CCHP system belonging to the office,residential and commercial communities and the comprehensive benefit of "3E" is used as the evaluation index.The results show the emission of pollutant saving rate,annual total cost rate and primary energy saving rate corresponding to the residential community are higher than those of the other two types of communities.The various indicators corresponding to the commercial community are the lowest.The various indicators of the office communities are between commercial and residential communities.Based on the optimization results of equipment capacity in the CCHP system belonging to the office community,residential community and commercial community,a multi-time scale optimization strategy is put forward to optimize the three types of communities step by syep on multi-time scale levels.Multi-time scale operation optimization was carried out with winter typical day,transition season typical day and summer typical day as examples,and the multi-time scale optimization results of the three types of typical days were compared and analyzed with the day-ahead majorization results.The majorization results show that the multi-timescale optimization strategy can not only accurately follow the day-ahead output plan,but also schedule all kinds of equipment s to quickly respond to various loads and renewable energy output changes.At the same time,it can also effectively ensure the operating economy of CCHP system and save the operating cost.In order to realize the diversification of community service functions,the number and proportion of office buildings,residential buildings and commercial buildings in the community was optimized,and a total of 25 kinds of building matching situations were determined.The equipment capacity optimization method is applied to determine the equipment capacity under varous matching situations,and the multi-time scale optimization strategy is applied to optimize the operation on winter typical day,transition season typical day and summer typical day.With the goal of lowest daily operating cost on three typical days,a multi-time scale optimization strategy is used to determine the optimal proportion of building types in the community.The optimization results show that the "3E" comprehensive benefits and daily operating costs corresponding to the system are at the optimal level under the optimal proportion of building types.