Research On Equalization Technology Of Multilayer Quasi-resonant Battery Pack Based On Buck-Boost

In the actual use of electric vehicles,multiple single batteries need to be connected in series and parallel to meet the power demand.However,there will be inconsistencies in the single cells before they leave the factory,and this inconsistency will gradually become more serious with repeated use of the battery pack,reducing the actual use capacity of the battery pack in series,and even causing the battery pack to burn and explode.Therefore,in order to effectively solve the inconsistency between series battery packs,battery equalization technology has been widely used in series battery packs.This article first introduces the current research status of battery equalization circuits,analyzes its working principle,takes the power battery pack of electric vehicles as the research object,and aims to improve the equalization speed of the buck-boost battery equalization circuit.In the buck-boost battery equalization circuit Multi-layer technology and quasiresonant technology are added,and a buck-boost-based quasi-resonant battery equalization circuit is designed.The equalization circuit increases the energy transmission path and improves the equalization speed,and there is no additional conduction caused by the addition of the equalization path loss.Considering the shortcomings of the battery equalization circuit in terms of volume and cost in the actual electric vehicle application,this paper carries out a modular equalization circuit design based on the designed equalization circuit.Using graph theory analysis to analyze the average equalization efficiency,average equalization speed,and the number of components used in the modular equalization circuit of the small module composed of different numbers of single cells,and finally determined the size of the small module composed of 12 single cells.The modular equalization circuit is suitable for the series battery pack application of electric vehicles.Finally,the equalization circuit designed in this paper and the simulation model and experiment platform of the comparison equalization circuit are built.Both the experiment and simulation results show that the battery equalization circuit designed in this paper has advantages in equalization speed.The application of multi-layer technology and quasiresonance technology to the buck-boost equalization circuit can increase the equalization speed and reduce the cost.A simulation model of the modular equalization circuit was built to verify the conclusions drawn by the research of modular equalization circuit.