Magnetoelectric equivalent circuit analytical method is presented for laminate composites of magneto- strictive Terfenol-D (TbxDy1-xFe2) and piezoelectric Pb(Zr1-xTix)O3 (PZT) operated in longitudinal mag- netized and...Magnetoelectric equivalent circuit analytical method is presented for laminate composites of magneto- strictive Terfenol-D (TbxDy1-xFe2) and piezoelectric Pb(Zr1-xTix)O3 (PZT) operated in longitudinal mag- netized and transverse polarized (or L-T), and transverse magnetized and transverse polarized (or T-T) modes. Magnetoelectric (ME) couplings both at low-frequency and resonance-frequency have been studied, and our analysis predicts that (i) the ME voltage coefficients of both L-T and T-T modes in- crease with increasing the thickness of the piezoelectric phase whereas magnetostrictive phase thickness keeps constant, and then tend to saturation when the thickness ratio of piezoelectric phase to magnetic phases is >3; (ii) there are the optimum thickness ratios that maximize magnetoelectric (ME) voltage coefficients for the two modes, which are dependent on elastic compliances ratio of piezoelec- tric phase and magnetostrictive phase; and (iii) the ME voltage coefficients are dramatically increased by a factor of ~Qm, when operated at resonance frequency. A series of Terfenol-D/PZT laminates were fabricated, and the results were compared with the theoretical ones. Experiments confirmed that equivalent circuit method is a useful tool for optimum designs of ME laminates.展开更多
通过经典传输线理论及部分元等效电路(partial element equivalent circuit,PEEC)方法,对高频继电器常闭型信号传输路径的分布电容、电感、电阻等参数进行提取,建立信号传输路径的等效电路模型。对其进行仿真分析得到继电器射频(radio f...通过经典传输线理论及部分元等效电路(partial element equivalent circuit,PEEC)方法,对高频继电器常闭型信号传输路径的分布电容、电感、电阻等参数进行提取,建立信号传输路径的等效电路模型。对其进行仿真分析得到继电器射频(radio frequency,RF)性能曲线,并讨论了影响继电器插入损耗、电压驻波比及隔离度的主要因素。高频继电器RF性能的实验测试结果与等效电路模型仿真结果符合较好,表明了所建立等效电路模型的正确性。展开更多
对锂离子电池的荷电状态(state of charge,SOC),健康状态(state of health,SOH)和剩余使用寿命(remaining useful life,RUL)进行准确估计是锂离子电池安全稳定运行的重要保障,该文提出一种结合充电电压片段和等效电路模型(equivalent ci...对锂离子电池的荷电状态(state of charge,SOC),健康状态(state of health,SOH)和剩余使用寿命(remaining useful life,RUL)进行准确估计是锂离子电池安全稳定运行的重要保障,该文提出一种结合充电电压片段和等效电路模型(equivalent circuit model,ECM)-数据驱动(data driven method,DDM)融合方法的锂离子电池SOC-SOH-RUL联合估计框架,实现对电池全生命周期的SOC、SOH和RUL的联合估计。首先提取与电池当前容量关联度最高的恒流充电电压曲线片段的上升时间作为健康特征(health factor,HF),利用外部训练集电池的老化数据,离线建立电池老化的最小二乘支持向量机(least squares support vector machine,LSSVM)模型。应用阶段,通过采集待测电池充电电压片段提取HF并代入老化模型进行SOH估计;对该电压区段进行ECM拟合,用阻容参数辨识值和容量估计值建立状态方程和观测方程,结合无迹卡尔曼滤波算法(unscented Kalman filter,UKF)进行SOC估计;用高斯过程回归(Gaussian process regression,GPR)对当前循环次数以前的DV随循环次数的变化进行映射,并借助老化模型预测容量的退化轨迹,实现RUL估计。实验结果表明,所提方法能够联合实现SOC、SOH和RUL的长期稳定估计。展开更多
基金Supported by the Office of Naval Research in USA
文摘Magnetoelectric equivalent circuit analytical method is presented for laminate composites of magneto- strictive Terfenol-D (TbxDy1-xFe2) and piezoelectric Pb(Zr1-xTix)O3 (PZT) operated in longitudinal mag- netized and transverse polarized (or L-T), and transverse magnetized and transverse polarized (or T-T) modes. Magnetoelectric (ME) couplings both at low-frequency and resonance-frequency have been studied, and our analysis predicts that (i) the ME voltage coefficients of both L-T and T-T modes in- crease with increasing the thickness of the piezoelectric phase whereas magnetostrictive phase thickness keeps constant, and then tend to saturation when the thickness ratio of piezoelectric phase to magnetic phases is >3; (ii) there are the optimum thickness ratios that maximize magnetoelectric (ME) voltage coefficients for the two modes, which are dependent on elastic compliances ratio of piezoelec- tric phase and magnetostrictive phase; and (iii) the ME voltage coefficients are dramatically increased by a factor of ~Qm, when operated at resonance frequency. A series of Terfenol-D/PZT laminates were fabricated, and the results were compared with the theoretical ones. Experiments confirmed that equivalent circuit method is a useful tool for optimum designs of ME laminates.
文摘通过经典传输线理论及部分元等效电路(partial element equivalent circuit,PEEC)方法,对高频继电器常闭型信号传输路径的分布电容、电感、电阻等参数进行提取,建立信号传输路径的等效电路模型。对其进行仿真分析得到继电器射频(radio frequency,RF)性能曲线,并讨论了影响继电器插入损耗、电压驻波比及隔离度的主要因素。高频继电器RF性能的实验测试结果与等效电路模型仿真结果符合较好,表明了所建立等效电路模型的正确性。
文摘对锂离子电池的荷电状态(state of charge,SOC),健康状态(state of health,SOH)和剩余使用寿命(remaining useful life,RUL)进行准确估计是锂离子电池安全稳定运行的重要保障,该文提出一种结合充电电压片段和等效电路模型(equivalent circuit model,ECM)-数据驱动(data driven method,DDM)融合方法的锂离子电池SOC-SOH-RUL联合估计框架,实现对电池全生命周期的SOC、SOH和RUL的联合估计。首先提取与电池当前容量关联度最高的恒流充电电压曲线片段的上升时间作为健康特征(health factor,HF),利用外部训练集电池的老化数据,离线建立电池老化的最小二乘支持向量机(least squares support vector machine,LSSVM)模型。应用阶段,通过采集待测电池充电电压片段提取HF并代入老化模型进行SOH估计;对该电压区段进行ECM拟合,用阻容参数辨识值和容量估计值建立状态方程和观测方程,结合无迹卡尔曼滤波算法(unscented Kalman filter,UKF)进行SOC估计;用高斯过程回归(Gaussian process regression,GPR)对当前循环次数以前的DV随循环次数的变化进行映射,并借助老化模型预测容量的退化轨迹,实现RUL估计。实验结果表明,所提方法能够联合实现SOC、SOH和RUL的长期稳定估计。
