Research And Design Of Data Acquisition And Management System For Lithium-ion Batteries

Lithium-ion batteries are widely used in pure electric vehicles,because of its significant advantages in the rapid development of new energy technologies today.As an important part of pure electric vehicles,battery data should be collected and managed.Excellent management can extend the battery life and ensure personal safety.The battery management system is used for the battery pack process to use scientific and effective management,protection and control of the battery,making the battery play the best role.Firstly,this paper analysis the external characteristics of the battery cell performance through research the battery equivalent model.Focusing on the key technology of battery management system,research and analysis the data acquisition and battery management.Processing the data and manage the system correspondingly according to the collected data.Consider on the battery pack thermal management and insulation testing technology research and design from a security perspective.In addition,due to the difference between the batteries,take SOC as a variable equalization method to eliminate the difference.The hardware circuit of the system adopts the modular structure to isolate the corresponding sub-functions and isolate it from the battery pack.So the sub-module circuit does not affect each other,improve the collection accuracy and is easy to replace hardware circuit and fault detection.The software part also uses modular structure,the battery data collection and invoking can be achieved by invoking each subroutine simply.Secondly,estimate and predict the SOC and SOH of battery in the realization of the basic functions of the battery management system.As the main state parameters of battery life and consistency,the state of charge(SOC)and state of health(SOH)of the battery must be estimated and predicted accurately.The method of estimating and predicting the battery SOC is based on the gray model for the single battery.Then analyze the shortcomings of traditional estimation method,regard balanced SOC as the SOC of batteries,reduce the estimation error and improve the consistency of the battery.The battery capacity ratio is used as the identification parameter of SOH and the method of estimating and predicting SOH is simulated by prognostics and health management after analyzing and defining the method of SOH of battery.The method is based on the empirical model of the battery to find the relationship between the battery capacity change,and then through the extremum disturbed and simple particle swarm optimization algorithm to identify the parameters of the model,and then get the battery capacity change relationship,which analyzed the state of health of battery.Finally,the function of the system is verified by experiment and simulation.The results show that the circuit and the model are feasible and effective.