In order to characterize the voltage behavior of a lithium-ion battery for on-board electric vehicle battery management and control applications,a battery model with a moderate complexity was established.The battery o...In order to characterize the voltage behavior of a lithium-ion battery for on-board electric vehicle battery management and control applications,a battery model with a moderate complexity was established.The battery open circuit voltage (OCV) as a function of state of charge (SOC) was depicted by the Nernst equation.An equivalent circuit network was adopted to describe the polarization effect of the lithium-ion battery.A linear identifiable formulation of the battery model was derived by discretizing the frequent-domain description of the battery model.The recursive least square algorithm with forgetting was applied to implement the on-line parameter calibration.The validation results show that the on-line calibrated model can accurately predict the dynamic voltage behavior of the lithium-ion battery.The maximum and mean relative errors are 1.666% and 0.01%,respectively,in a hybrid pulse test,while 1.933% and 0.062%,respectively,in a transient power test.The on-line parameter calibration method thereby can ensure that the model possesses an acceptable robustness to varied battery loading profiles.展开更多
With the rise of the electric vehicle industry,as the power source of electric vehicles,lithium battery has become a research hotspot.The state of charge(SOC)estimation and modelling of lithium battery are studied in ...With the rise of the electric vehicle industry,as the power source of electric vehicles,lithium battery has become a research hotspot.The state of charge(SOC)estimation and modelling of lithium battery are studied in this paper.The ampere-hour(Ah)integration method based on external characteristics is analyzed,and the open-circuit voltage(OCV)method is studied.The two methods are combined to estimate SOC.Considering the accuracy and complexity of the model,the second-order RC equivalent circuit model of lithium battery is selected.Pulse discharge and exponential fitting of lithium battery are used to obtain corresponding parameters.The simulation is carried out by using fixed resistance capacitance and variable resistance capacitor respectively.The accuracy of variable resistance and capacitance model is 2.9%,which verifies the validity of the proposed model.展开更多
A water balance has a significant impact on the overall system performance in proton exchange membrane fuel cell.An actual fuel cell application has a dynamic electrical load which means also dynamic electrical curren...A water balance has a significant impact on the overall system performance in proton exchange membrane fuel cell.An actual fuel cell application has a dynamic electrical load which means also dynamic electrical current.Therefore,since this electrical current is known,the water production from the fuel cell reaction is also able to be predicted.As long as the fuel cell water transportation model is provided,the present liquid water inside the porous medium is also able to be modeled.A model of the liquid water saturation level in a fuel cell in unsteady load condition was proposed.This model is a series of the water transportation model of water saturation level for the final output of proton exchange membrane(PEM) fuel cell to predict the flooding or drying of PEM fuel cell.The simulation of vehicle fuel cell in different dynamic load profiles and different inlet air conditions was done using this model.The simulation result shows that PEM fuel cell with different dynamic load profiles has different liquid water saturation level profiles.This means that a dynamic load fuel cell requires also a dynamic input air humidification.展开更多
基金Project(50905015) supported by the National Natural Science Foundation of China
文摘In order to characterize the voltage behavior of a lithium-ion battery for on-board electric vehicle battery management and control applications,a battery model with a moderate complexity was established.The battery open circuit voltage (OCV) as a function of state of charge (SOC) was depicted by the Nernst equation.An equivalent circuit network was adopted to describe the polarization effect of the lithium-ion battery.A linear identifiable formulation of the battery model was derived by discretizing the frequent-domain description of the battery model.The recursive least square algorithm with forgetting was applied to implement the on-line parameter calibration.The validation results show that the on-line calibrated model can accurately predict the dynamic voltage behavior of the lithium-ion battery.The maximum and mean relative errors are 1.666% and 0.01%,respectively,in a hybrid pulse test,while 1.933% and 0.062%,respectively,in a transient power test.The on-line parameter calibration method thereby can ensure that the model possesses an acceptable robustness to varied battery loading profiles.
基金Project(51507073)supported by the National Natural Science Foundation of China。
文摘With the rise of the electric vehicle industry,as the power source of electric vehicles,lithium battery has become a research hotspot.The state of charge(SOC)estimation and modelling of lithium battery are studied in this paper.The ampere-hour(Ah)integration method based on external characteristics is analyzed,and the open-circuit voltage(OCV)method is studied.The two methods are combined to estimate SOC.Considering the accuracy and complexity of the model,the second-order RC equivalent circuit model of lithium battery is selected.Pulse discharge and exponential fitting of lithium battery are used to obtain corresponding parameters.The simulation is carried out by using fixed resistance capacitance and variable resistance capacitor respectively.The accuracy of variable resistance and capacitance model is 2.9%,which verifies the validity of the proposed model.
文摘A water balance has a significant impact on the overall system performance in proton exchange membrane fuel cell.An actual fuel cell application has a dynamic electrical load which means also dynamic electrical current.Therefore,since this electrical current is known,the water production from the fuel cell reaction is also able to be predicted.As long as the fuel cell water transportation model is provided,the present liquid water inside the porous medium is also able to be modeled.A model of the liquid water saturation level in a fuel cell in unsteady load condition was proposed.This model is a series of the water transportation model of water saturation level for the final output of proton exchange membrane(PEM) fuel cell to predict the flooding or drying of PEM fuel cell.The simulation of vehicle fuel cell in different dynamic load profiles and different inlet air conditions was done using this model.The simulation result shows that PEM fuel cell with different dynamic load profiles has different liquid water saturation level profiles.This means that a dynamic load fuel cell requires also a dynamic input air humidification.
