| Energy storage technology is the key technology for sustainable energy development in the future.Power storage technology,which is composed of power type lithium ion batteries and supercapacitors,is widely used in many fields such as renewable energy,smart grid and electric propulsion equipment.Because the inevitable difference between the energy storage monomer lead to inconsistent parameters,prone to some or some of the energy storage monomer overcharge or over discharge phenomenon,with the increase in the number of charg e and discharge,will lead to the actual capacity of the series storage Down,reduced service life.Therefore,the energy balance between the multi-monomer of the energy storage system is one of the important technologies of the energy storage system.In this paper,the multi-element equalization technology of the advanced energy storage unit is compared.The key step is to shorten the equilibrium path and realize the direct equilibrium of the energy storage monomer for the large-capacity series energy storage system under complex conditions.A four-element direct equalization circuit is proposed,which can realize the direct equilibrium between the four monomers,but the difference is poor.For this reason,a multi-monomer equilibrium topology is proposed to realize the direct equilibrium of any monomer.Non-adjacent energy storage monomer is not balanced,without the aid of intermediate monomer for energy transfer,shorten the equilibrium path,improve the efficiency of the balance.By introducing the c oupling inductance and effectively controlling the current flow,the two-way energy transfer channel is constructed,and the direct energy balance is realized.The effects of equalizer parameters on the equalization process are studied,and the simulation model of the equilibrium topology is established,and the simulation is carried out.The simulation results show that the equilibrium model is equal to each other.The magnetic components of the main circuit adopt the planar multi-winding coupling inductors composed of planar cores and PCB windings.The structure and parameters are analyzed and calculated to ensure the consistency of the parameters.The number of switches used in the balanced topology is very large,and the switch tube source is very common.In this way,the optocoupler is designed to isolate the high-density driving circuit,and the battery voltage is used to supply the optocoupler chip,and the multi-The power density of the device.The structure of multi-monomer direct equalization system controller is designed with DSP chip as the core,and the reliable control of two balanced working modes is realized.The main energy storage unit in the main circuit is made up of 6 sections of 3300 m Ah series lithium ion battery.The system is carried out under the condition of monomer balance and monomer balance in the group.Experimental testing and analysis.According to the experimental results,the multi-element direct equalization system of series energy storage can make the energy equalization between cell-to-cell paths between any monomers,and the equilibrium path is shortened and the equilibrium velocity is improved compared with the current equilibrium topology. |
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