| On September 22,2020,China pledged at the UN General Assembly that it will strive to reach a peak in carbon emissions by 2030 and be carbon-neutral by 2060.China’s energy system will undergo a profound transformation in the medium and long term,and the share of non-fossil fuels is expected to increase significantly.The energy plan for the 14 th five-year plan is expected to be good in the short term.Under the vision of achieving carbon neutrality,we want to effectively solve ecological and environmental problems,reduce carbon dioxide emissions and gradually replace fossil resources such as coal,the development of renewable energy is the fundamental way and the best choice.It is estimated that in the future the actual cost of electricity generated from clean energy sources worldwide will be as low as 2 cents per kilowatt hour by 2050.Compared with fossil energy,renewable energy has absolute cost advantage and will dominate the future development of energy industry.In recent years,distributed generation technology based on renewable energy has been applied more and more widely.At present,wind and photovoltaic generation stations transmit electricity through the form of interconnection with the power grid,however,when a large number of distributed power supply is connected to the power grid,it may lead to power imbalance,uncontrollable and difficult to manage the situation,and then lead to such problems as poor stability and low power quality.In order to avoid the contradiction between the power grid and the distributed generation(DG),the independent wind and solar power generation system is used to meet the load demand first.Independent wind and solar power generation is influenced by weather factors and has strong instability,so it needs a large amount of installed capacity to fully meet the load demand,which leads to a large number of power abandonment.In this paper,aiming at the phenomenon of excessive waste of electricity in independent wind-solar power generation system,a large-scale office in a remote area is taken as the research object,battery energy storage system and electrolyzed water hydrogen production system are added,the charge and discharge characteristics of the battery are used to balance the power of the system,and hydrogen production from electrolyzed water is used to absorb some of the waste electricity during the non-heating period.In order to determine the optimal capacity allocation of the components of the wind-solar combined battery energy storage system from the economic point of view,the power simulation software Homer is used.Further consider to increase the thermal storage electric boiler to increase the system load,in the heating period.By analyzing and comparing the operation mode of regenerative electric boiler and different boiler capacity,the system is optimized with the goal of eliminating the largest amount of waste electricity and the lowest operation cost by using python.First of all,the simulation software Homer mainly through simulation,optimization and sensitivity analysis to determine the optimal capacity configuration of system components.According to the research location selected in this paper,the wind speed,the light radiation value and the electric load are analyzed statistically.Through the simulation function of Homer software,the data of 8760 hours in the whole year is formed,and the data is imported into the software to pave the way for the follow-up optimization simulation.Secondly,the electrical energy software Homer is used to build models of wind turbines,photovoltaic panels,storage batteries,convertors and electrolyzers.In order to minimize the total net present cost(NPC),3142 k W photovoltaic(PV),21 MW battery and 32 wind turbine each with a capacity of 100 k W,and 1960 k W converter are chosen as the most optimal configuration through a series of optimization and comparison.Simulation results show that the minimum COE is 0.503 k Wh;the total number of NPC is 35,600,000 RMB.Finally,since the independent wind-and-solar power generation system is used to generate electricity in this paper,the installed capacity needs to be increased to fully meet the demand for electricity consumption,so more electricity will be discarded.In order to improve the utilization rate of renewable energy,and taking into account the reduction of carbon emissions,in this paper,the regenerative electric boiler is considered to replace the coal-fired boiler to provide heat,which can not only eliminate the large amount of excess electricity in the system,but also alleviate the pressure of heating period in winter in North China.By analyzing the traditional two-stage operation of regenerative electric boiler and tracking the abandoned power operation,it can be concluded that the effect of eliminating excess electricity is poor in the traditional two-stage operation of electric boiler,so as to the operation of tracking abandoned power,although the effect of absorbing and discarding air is good,the fluctuation of daily heat output with discarding electricity is large,and stable heat supply can not be achieve.Therefore,the multi-objective optimization operation mode of the solid heat storage electric boiler is presented.Therefore,the multi-objective optimization operation mode of the solid heat storage electric boiler is adopted,and the objective function is the maximum rejection and the minimum purchase cost through one-dimensional mathematical modeling,the multi-objective optimization problem is solved by genetic algorithm using Python software with the constraints of eliminating rejected power,system power balance,electric boiler power,heat storage and regulation times,the optimal compromise solution is selected from the pareto solution set,and the optimal configuration capacity of the regenerative electric boiler is 6 units,which can absorb about 32% of the waste electricity in the system every year.In the end,52.2% of the power is wasted by the combined method of energy storage,hydrogen production and heat storage,which verifies the feasibility of the proposed energy dissipation strategy.This elimination method can better help the establishment of off-grid renewable energy power generation system,and then for the power system is not very developed areas,can achieve power self-sufficiency,and in the future,the development of hydrogen is getting better and better,the approach would generate a share of the proceeds from hydrogen sales,which would further promote the widespread use of stand-alone renewable power generation systems. |
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