The Research Of The Method Of Internal Resistance Of Lead-acid Battery

The internal resistance of lead-acid batteries is the main basis for judging its performance.In this paper,the measurement method of lead-acid battery internal resistance is studied.First we build a hardware platform as a hardware support to get high-precision parameters for resistance calculation.On this basis,this paper integrated the fast Fourier transform into the data processing process,and realized the high precision internal resistance measurement.After the resistance is obtained,the parameter composition is estimated,and the ohmic resistance of the lead-acid battery is deduced from the impedance,and the performa nce of the lead-acid battery is determined.Aiming at the requirement of the measurement accuracy of lead-acid battery internal resistance,this paper first designs the overall scheme.The hardware test platform was built by AC discharge method,the internal resistance measurement algorithm based on fast Fourier transform lead acid battery was designed,and the modular design of the software was realized.In the construction of the hardware platform,we chose STM32F3 series control chip as the core,selected the components,and built several circuits.It is to obtain high-precision current and voltage parameters for internal resistance measurement.Then this paper analyzed the limitations of the existing data processing.and combined the fast Fourier transform with the data processing.Firstly,the feasibilit y of the algorithm was verified by using the fast Fourier transform channel of DSO3064.After the preliminary judgment,the internal resistance measurement algorithm based on fast Fourier transform was simulated in MATLAB.The fast Fourier transform points were obtained,and the multi-frequency detection was carried out under the number of points.We analyzed the experimental results and verified the feasibility of the algorithm.After analysis and verification,this paper used the MDK ARM as the software development platform to write the C program to realize the internal resistance measurement process based on the fast Fourier transform.In order to meet the functional requirements of the software,this paper completed the sub-module design of the software process,and finally used the hardware platform to measure the resistance of the lead-acid battery,which verified the measurement result of the hardware platform to meet the precision requirement s.Finally,this paper estimated the composition of the internal resistance measurement results.Based on the RLC circuit model,we used the multi frequency method to construct the equation,and we solved the equation in MATLAB.Compared with the results o f the analysis,it is concluded that the ohmic resistance of the lead-acid battery is basically the same under the excitation of different frequencies,and the use of the ohmic resistance is more convincing.