Research On Life Model And Durability Management Of Electric Bus Power Battery System

The life of power battery for electric bus is one of the key issues that constrains the alternative of electric buses to the conventional internal combustion vehicle.From the application point of view,the key factors that affect the battery life during the operation were identified,and the influence of the key factors were analyzed.The battery life prediction model was established,and the control parameters aiming at the long life management were obtained through targeted analysis,to extend the life of power batteries and improve the durability of power battery systems.(1)The battery life test was carried out,in the condition of the precise temperature control,charging capacity,and SOC range,the battery charge and discharge cycle test was carried out,the standard capacity was tested at ambient temperature at regular intervals.By observing the change of capacity with the number of cycles under various conditions,the battery life decline characteristics were studied.(2)The battery life prediction model was established.The life prediction model including the capacity retention rate,ambient temperature,charging rate,discharge rate and cycle number was established,and the model parameter identification was carried out based on the life test results.Through the remote monitoring system,the battery capacity of the sample vehicle was obtained,and the model of the battery life prediction model was compared to verify the effectiveness of the prediction model.(3)For electric vehicle power battery system,based on the battery life prediction model,the control parameters of the ambient temperature,by analyzing the charging magnification and the discharge magnification with the long life management of the power battery were obtained,and the durability management target of the power battery system was realized.