Research On The Co-estimation Of SOC And SOH And On Charging-discharging Strategy Of The Vehicular Lead-acid Battery

Lead-acid battery is the auxiliary power supply of the oil-fueled automotive,it provides the starter and parts of the electricity loads with power.SOC(State of Charge)and SOH(the State of the Health)are used to describe state of charge and state of health of leadacid battery respectively,they are important input parameters of the power management policy in those oil-fueled automotive which are equipped with energy management system,the estimation accuracy of SOC and SOH has a direct relationship with the effectiveness of energy management system.Excessive discharge current of lead-acid battery makes its capacity drops too fast,resulting in shorter service life,by controlling the current in charging-discharging cycles,the desired service life of the lead-acid battery could be achieved.This thesis is supported by National Natural Science Foundation and enterprise cooperation project.The algorithm of co-estimation of SOC and SOH for vehicular leadacid battery and the charging-discharging strategy which takes the service life of the leadacid battery into consideration are researched.Firstly,the equivalent circuit model of battery is compared and analyzed from precision and complexity;Secondly,the suitable Randles equivalent circuit model has been chosen based on the contrast results,SOCSOH-Voc relation model has been established by experiments,a SOC and SOH coestimation method has been proposed based on the Least Square(LS)and the Kalman Filter(KF)method;thirdly,the relationship among SOH,discharging current and charging-discharging cycles of lead acid battery has been obtained by experiments,and the relationship between the equivalent internal resistance and SOC has also been obtained through experiments,what's more,the relationship of output power and output current has been obtained,a charging-discharging strategy which could extend the battery life has been proposed based on the above relationships.At last,the overall design and detailed design have been carried out on the SOC and SOH estimation system and on the charging-discharging simulation experiment programme.The effectiveness of the estimation method has been verified through the actual charging-discharging experiments based on the platform,the charging-discharging strategy validity has been verified based on the simulation experiment programme.