| In today’s traditional energy can not meet the actual needs of the background,renewable energy micro-grid has been more rapid development and progress,because the control mode and economic factors are the two major problems that AC microgrid is facing in the process of rapid expansion,and DC charge is the most popular option in practical production and life,after continuous improvement and improvement,DC micro-grid control is more simple,simple and has the characteristics of high efficiency in the comprehensive utilization of distributed output power supply.In this paper,we mainly analyze the photovoltaic DC micro-grid system combined with supercapacitor and battery,and also study the operation and control mode of the micro-grid system.Firstly,the scheme of energy management in hybrid energy storage system is studied to solve the two main problems,so as to further improve the battery life and Storage Energy Space;Two control modes,namely maximum power tracking control(MPPT)and constant voltage control(CVC),are set up for different requirements of practical operation.After that,the application mode and working principle of bi-directional DC/DC converter and bi-directional DC/AC converter in the system are analyzed.In addition,the management mode and strategy in the application of hybrid energy storage system are put forward in the course of the research,which mainly takes into account that the bus voltage can not be controlled effectively in the micro-grid system,the strategic approach to this management is to use a Stage of Charge(SOC)operation for zonal limit management.In order to solve the problem of over-charging and over-discharging in the process of using ultracapacitors,it is necessary to adjust and control the power distribution mechanism of the hybrid energy storage system in the corresponding application scenario state,the over-charging and over-discharging of ultracapacitor can be effectively controlled,and the limiting factors of power supply system can be eliminated.Finally,based on the Matlab/Simulink platform to complete the system model building,and then through the way of modeling and simulation to verify the different working mode of the operating state,and the different working state simulation analysis.Both the simulation waveform and the numerical results show that the proposed control strategy is more stable and can match the corresponding power more quickly than the droop control,this validates the control strategy studied in this paper and proves the corresponding optimization results. |
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