Research On Active Equalization Of Battery Based On Inductance

With the continuous reduction of non renewable energy sources such as oil and coal and the improvement of environmental importance in the world,the topic of replacing clean energy has received continuous attention.As one of the main energy consumption of civilian products,the power source of automobile has gradually evolved from traditional oil to natural gas,ethanol,oil and electricity mix,and so on,and the pure electric vehicle industry has been developing rapidly in recent years.As a power source of a pure electric vehicle,the problem of battery capacity inconsistency between the large capacity batteries formed by a series of battery monomers is urgently needed to solve.Based on the balanced topology of inductors,this dissertation designs an active balancing scheme for electric vehicle power lithium batteries,which solves the problems of battery life reduction and the mileage of electric vehicles decreasing due to the difference in battery capacity.In this dissertation,according to the relationship between the residual capacity of the battery and the charged state of the battery,the mathematical model of the battery is established,and the parameters related to the voltage IFP1865140 in the model of the lithium battery are identified by experiments.The voltage of the battery pack is selected as the index of the equalization of the battery.Using inductor as energy storage element,the current decreasing equalization topology is established to transfer energy between batteries,and the current characteristics of the circuit are analyzed according to the different position of the cell in the battery pack.According to the current SOC of the battery,the time of the equalization and the duty cycle of the driving signal are determined,and the control strategy of the battery equalization based on the current decreasing equalization topology is designed.Compare the complexity of topology structure of various inductance-based cell equalization schemes and the use of various equalization strategies,the requirements of battery pack number,by comparing the equalization process of various induction-based equalization schemes,The equalization time of the corresponding strategy is calculated,and the generality of the battery equalization control strategy in other inductance based battery equalization topologies is analyzed.Finally,based on the MATLAB/SIMULINK simulation platform,the models of all kinds of equalization schemes are built for equalization simulation.The simulation and experimental results show that the active equalization topology is simple,the equalization speed is fast,and the control strategy is universal.It can realize the fast equalization between the battery cells.In this dissertation,the research of active battery equalization based on inductance has a certain reference value for the application of electric vehicle battery pack equalization.