A Study On Matching Performance Of Building Renewable Energy System Based On Forecasting Of Power And Load

The energy crisis and environmental pollution problem are becoming more and more serious,which makes the energy system in the world translate to low carbonization.The building system,which accounts for nearly one third of the social energy consumption,is also developing towards a Low-carbon and clean.Besides,the role of building is changing from energy consumer to energy producer with the purposing of new concepts such as ultra-low/zero energy building.The proportion of solar energy,wind energy and other renewable energy sources in building energy system is increasing gradually,but the instability and discontinuity of renewable energy have a great impact on the matching of building energy system.Matching is an important technical parameter for examining the performance of building energy systems and increasing the proportion of renewable energy applications,and it has become a research hotspot in recent years.The dynamic changes of power generation and load in the future can be grasped by forecasting of power and load,most current forecasting research is oriented to the grid,which is convenient for dispatching.In this paper,the forecasting technology is applied to the building energy system to predict the power generation and load,thus,it can optimize the control and scheduling of the system to achieve the goal of improving the matching and economic efficiency of the building renewable energy system.In this paper,a three-story 270m~2 residential building under meteorological conditions in Tianjin is studied.Firstly,the prediction model of pv,fan generation power,building load using BP neural network,and a MATLAB-TRNSYS model of renewable energy system based on forecasting were established.Secondly,the energy management control strategy of building renewable energy system based on forecasting is proposed,and the simulation calculation was carried out for the whole year and compared with the conventional building energy system.The annual waste power of the system is 2688 kW?h,and it costs 2160 yuan to purchase electricity from the grid,and the waste power and power purchase cost about 30%and 43%of the conventional building energy system.Then,the matching indexes:on-site energy fraction(OEF_r)and on-site energy matching(OEM_r)are applied to analyze the matching performance of energy system.On the annual scale,OEF_r of building renewable energy systems based on forecasting and conventional building energy systems were 0.75 and 0.51,OEM_r were 0.88 and 0.60.On the hourly time scale,compared with the conventional system,OEF_r and OEM_r of system based on forecasting increased by 22.92%and 28.78%respectively.Finally,management and control strategy of demand side for building renewable energy system based on virtual energy storage of air conditioning load is proposed,optimizing the dispatching from the demand side and further improving the matching and economy of the system.After dispatching,the number of battery discharge cycles was reduced from 11 to 7times,the discharge depth was reduced to 28.13%from 51.50%,the life of storage battery was improved,OEF_r and OEM_r of system increased by 8.19%and 8.45%compared with the system before dispatching.