Research And Implementation Of On-line State Parameters Estimation For Vehicular Lead-acid Batteries

Lead-acid battery is the main component of the vehicle power supply system,which is mainly used for starting and auxiliary power supply in the traditional fuel vehicles.The state parameters of lead-acid battery are important basis for effective battery energy management.State of Charge(SOC)and State of Health(SOH)are two important parameters of batteries,their value is one of the inputs for power management strategy of energy-saving and environment-friendly vehicles,the estimation accuracy of them is directly related to the life of battery and the effectiveness of vehicle energy management.In this paper,based on the Anhui Province Natural Science Fund and enterprise cooperation project,the real-time on-line estimation method for the state parameters SOH and SOC of lead-acid batteries in the traditional fuel vehicles is studied.First of all,through the analysis of the present estimation methods for the state parameters and equivalent circuit models of battery,a simplified Randles equivalent circuit model of leadacid batteries is established.Then,the SOH estimation based on parameters of equivalent circuit model and the SOC estimation based on the open circuit voltage(Voc)are carried out,the parameters of circuit model in the estimation process are identified based on the unscented Kalman filter(UKF).The on-line SOC,SOH estimation method based on the relationship between the battery state parameters SOC,SOH,Voc is put forward combined with the experiment,the method of the on-line estimation of state parameters are given.What's more,the above estimation method of battery state parameters is actualized on the chip,the prototype node of battery sensor is developed,the parameter acquisition circuit and the LIN communication circuit are designed with the programs of parameter acquisition,parameter estimation and LIN communication written.Finally,an experimental platform based on CANoe is established,the experimental scheme,experimental steps and data acquisition methods of the battery is designed,The experimental results demonstrate that the estimation accuracy of the battery SOH estimation method and the on-line SOC estimation method are accurate and reliable.The research in this paper is of great significance to strengthen the protection of battery,improve the efficiency of power management,reduce the energy consumption and explore the realization of high-precision complex algorithm in the battery sensor.