为提高锂电池荷电状态的估算精度及模拟锂离子电池实际充放电特性的准确性,本文通过改进现有的PNGV等效电路模型,在PNGV模型基础上,增加一节RC并联模块,使模型更好的反映电池的极化效应。同时,通过实验获取电池充放电特性,为卡尔曼滤波...为提高锂电池荷电状态的估算精度及模拟锂离子电池实际充放电特性的准确性,本文通过改进现有的PNGV等效电路模型,在PNGV模型基础上,增加一节RC并联模块,使模型更好的反映电池的极化效应。同时,通过实验获取电池充放电特性,为卡尔曼滤波器提供精确的参数,并提出了电池的开路电压曲线模型,通过Matlab拟合验证满足精度要求。最后采用扩展卡尔曼滤波(extended kalmanfilter,EKF)算法对锂电池荷电状态(state of charge,SOC)进行估算,并与安时积分法进行比较。实验结果表明,估算最大误差不超过4.5%,平均不超过3%,提高了SOC的估算精度。该研究为电动汽车运行工况提供了理论依据。展开更多
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
The effect of the parameters on the open-circuit voltage, V_(OC) of a-Si:H/c-Si heterojunction solar cells was explored by an analytical model. The analytical results show that V_(OC) increases linearly with the logar...The effect of the parameters on the open-circuit voltage, V_(OC) of a-Si:H/c-Si heterojunction solar cells was explored by an analytical model. The analytical results show that V_(OC) increases linearly with the logarithm of illumination intensity under usual illumination. There are two critical values of the interface state density(D_(it)) for the open-circuit voltage(V_(OC)), D_(it)^(crit,1) and D_(it)crit,2(a few 1010 cm^(-2)·e V^(-1)). V_(OC) decreases remarkably when D_(it) is higher than D_(it)^(crit,1). To achieve high V_(OC), the interface states should reduce down to a few 1010 cm^(-2)·e V^(-1). Due to the difference between the effective density of states in the conduction and valence band edges of c-Si, the open-circuit voltage of a-Si:H/c-Si heterojunction cells fabricated on n-type c-Si wafers is about 22 mV higher than that fabricated on p-type c-Si wafers at the same case. V_(OC) decreases with decreasing the a-Si:H doping concentration at low doping level since the electric field over the c-Si depletion region is reduced at low doping level. Therefore, the a-Si:H layer should be doped higher than a critical value of 5×10^(18) cm^(-3) to achieve high V_(OC).展开更多
文摘为提高锂电池荷电状态的估算精度及模拟锂离子电池实际充放电特性的准确性,本文通过改进现有的PNGV等效电路模型,在PNGV模型基础上,增加一节RC并联模块,使模型更好的反映电池的极化效应。同时,通过实验获取电池充放电特性,为卡尔曼滤波器提供精确的参数,并提出了电池的开路电压曲线模型,通过Matlab拟合验证满足精度要求。最后采用扩展卡尔曼滤波(extended kalmanfilter,EKF)算法对锂电池荷电状态(state of charge,SOC)进行估算,并与安时积分法进行比较。实验结果表明,估算最大误差不超过4.5%,平均不超过3%,提高了SOC的估算精度。该研究为电动汽车运行工况提供了理论依据。
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(11374094)supported by the National Natural Science Foundation of ChinaProject(2013HZX23)supported by Natural Science Foundation of Hunan University of Technology,ChinaProject(2015JJ3060)supported by Natural Science Foundation of Hunan Province of China
文摘The effect of the parameters on the open-circuit voltage, V_(OC) of a-Si:H/c-Si heterojunction solar cells was explored by an analytical model. The analytical results show that V_(OC) increases linearly with the logarithm of illumination intensity under usual illumination. There are two critical values of the interface state density(D_(it)) for the open-circuit voltage(V_(OC)), D_(it)^(crit,1) and D_(it)crit,2(a few 1010 cm^(-2)·e V^(-1)). V_(OC) decreases remarkably when D_(it) is higher than D_(it)^(crit,1). To achieve high V_(OC), the interface states should reduce down to a few 1010 cm^(-2)·e V^(-1). Due to the difference between the effective density of states in the conduction and valence band edges of c-Si, the open-circuit voltage of a-Si:H/c-Si heterojunction cells fabricated on n-type c-Si wafers is about 22 mV higher than that fabricated on p-type c-Si wafers at the same case. V_(OC) decreases with decreasing the a-Si:H doping concentration at low doping level since the electric field over the c-Si depletion region is reduced at low doping level. Therefore, the a-Si:H layer should be doped higher than a critical value of 5×10^(18) cm^(-3) to achieve high V_(OC).
