Research On Energy Management Strategy Of Micro Grid Based On Hybrid Energy Storage

As the fossil energy crisis and environmental pollution become more and more serious,clean renewable energy becomes the inevitable choice of energy structure adjustment.The power system planning and operation has been greatly influenced by the instability of the output power of distributed energy,such as solar energy and wind energy.The hybrid energy storage system composed of accumulator and super capacitor can solve the above problems.Dc micro power grid based on the analysis of stable operation on the basis of the demand for energy storage,battery-super capacitor cascade approach is adopted to form hybrid energy storage system,in a single hybrid energy storage subsystem for battery and super capacitor,and in the micro grid system of different hybrid energy storage subsystem respectively,puts forward the corresponding power allocation method to realize the smooth control of the battery current,reduce the battery charge and discharge times,prolong the service life of battery,improve the running stability of the micro grid.In this paper,the system structure are mainly carried out in the following aspects?In this paper,the system structure are mainly carried out in the following aspects:Firstly,summarizes the research background and significance of this paper,discussed the micro grid and hybrid energy storage system and its research status,the control strategy of the research of the current dc micro power system stability and the problems faced by energy storage.Secondly,this paper describes the basic structure and operation mode of micro grid,and proposes an improved hybrid energy storage system topology.In the analysis of the hybrid energy storage system output characteristic and working principle of storage battery and super capacitor,gives its mathematical model,and the hybrid energy storage system of bi-directional DC/DC converter's main circuit to carry on the design and calculation of the parameters.Thirdly,research with the method of battery-super capacitor cascade constitute a hybrid energy storage system to bring down the dc bus power fluctuations,by super capacitor charge and discharge control dc bus power fluctuations in the high frequency part,information according to the super capacitor voltage of battery charging and discharging control,keeping a super capacitor voltage in normal work within the scope of low frequency part of indirect compensation dc bus power fluctuations.In a mixture of different energy storage subsystem,combined with the traditional droop control with the hybrid energy storage subsystem SOC information,put forward a kind of power allocation method based on SOC,improve the running stability of the micro grid.Fourthly,construct the experimental control platform of the dc micro-grid system,and design the software and hardware platform of the control strategy.Through the comparative analysis of single hybrid energy storage system of storage battery and super capacitor power fluctuations and multiple power distribution between the hybrid energy storage subsystem,reflects the presented control strategy of hybrid energy storage compared with the traditional control strategy of hybrid energy storage can prolong the service life of the battery,and smooth the performance of the dc bus power fluctuations have significantly improved.It can be proved that the energy management strategy proposed in this paper has certain theoretical significance and practical application value.