Study On SOC Estimation Method Of Lithium-ion Battery And Control Strategy Of Energy Management For FCEV

In recent years, because of the traditional automobile has limited method to solvethe increasingly serious energy shortage and environmental pollution problems, newenergy vehicles, especially the fuel cell electric vehicles(FCEV) with clean andrenewable fuel sourses and almost zero emission, get more and more attention. Aimedat the power battery and the control strategy of energy management, the related theoryand experimental research were carried on.First of all, characteristics of35A ternary material lithium-ion battery cells wereintroduced, based on the principle of the lithium-ion battery. Then the unit cellexperiments were carried out under different temperatures and differentcharge-discharge rates. In addition, the HPPC performance experiments were carriedout under the different charge-discharge rates.The experiment results show that lowtemperature and high charge-discharge rate have a greater impact on the batteryvoltage and charge-discharge capacity.Secondly, the main factors influencing the power battery’s SOC were introducedand the principle of the linear kalman filter, Extended kalman filter, and Unscentedkalman filter were discussed. Then the EKF models and the UKF model of SOC’sestmation based on the Thevenin battery model and the empirical formula model werecreated in the Matlab/Simulink respectively. The simulation results show that theempirical formula model is more accurate than the Thevenin battery model whenusing the same algorithm, while the model based on UKF is more accurate than thatbased on EKF when the temperature is in both high and low area.Finally, the pros and cons of the On/Off control strategy and power followcontrol strategy were analyzed when taking a section of fuel cell electric vehicle as anexample. Then the instantaneous optimization control strategy based on the fuelconsumption equivalent equations was studied and established in Matlab/Simulink.Besides, the simulation of the power system was carried out combined ADVISOR intypical operating conditions of Chinese cities. The simulation results show that theinstantaneous optimization control strategy has the highest economy performance onthe premise of guaranteeing the power performance.