Research On Energy Management Strategy Based On DC Microgrid System

Under the background of high intensity consumption of fossil energy,distributed energy technology is favored by all countries in the world.Distributed energy technology can realize comprehensive utilization of energy and has a good development prospect.The output of distributed generation can not be controlled to affect the stability of power grid,DC microgrid can overcome the inverse peak regulation characteristics of distributed power supply,reduce the peak-to-valley difference and improve the anti-interference ability of the system by coordinating the distributed power supply,energy storage equipment and load through energy management strategy.Therefore,the core energy management of DC mierogrid is studied in this paper.Firstly,this paper carries on the theoretical analysis to the photovoltaic cell,the wind turbine,the battery,the load in the DC microgrid,studies the mathematical model of each function unit,and studies the control of each system,and simulates each function unit in the Matlab.MPPT control of photovoltaic cells is realized by conductance increment method,the maximum wind energy capture of wind turbine is realized by optimal tip speed ratio tracking method,and the running state of battery is analyzed.The constant voltage output of battery under variable load is realized.Secondly,for the problem of DC bus voltage stability in the process of DC microgrid energy management,this paper proposes an energy management scheme based on the control of each component unit in the microgrid.The energy management strategy is ed into three control levels with different functions.Each control layer has different input and output.Through the coordination between each layer,the overall operation of DC microgrid is judged,and the operation decision is made to realize the adaptive decision of complex operation state.According to the real meteorological data measured in the laboratory,the simulation shows that the energy management strategy proposed in this paper can maintain the bus voltage stability.Finally,on the existing experimental platform of DC microgrid,the energy management strategy of DC microgrid proposed in this paper is verified experimentally.Experimental results show that the bus voltage fluctuates in the range of±1%when the power supply andload change,thus maintaining high power quality,The experimental results show that the proposed strategy is correct and feasible,and has good control effect.