This paper proposes an improved modularizable high-frequency battery equalizer with multi-winding transformer for energy storage systems. The involvement of parasitic components in circuit resonance, along with the ad...This paper proposes an improved modularizable high-frequency battery equalizer with multi-winding transformer for energy storage systems. The involvement of parasitic components in circuit resonance, along with the addition of a resonant network, enables soft-switching for the power switches to reduce the switch voltage stress due to high frequency switching operation. The proposed circuit is designed to operate at switching frequency of 1 MHz. The detailed analysis of circuit operation is provided. At last, the feasibility and performance of the proposed battery equalizer are demonstrated through the system implementation and experimental tests of a prototype circuit. Experimental results have shown zero voltage switching (ZVS) is achieved on the switches.展开更多
In this paper, equivalent circuits for high frequency multi-winding magnetic components are derived from finite element （FE） computations. Lumped parameter models are first presented, based on previously published w...In this paper, equivalent circuits for high frequency multi-winding magnetic components are derived from finite element （FE） computations. Lumped parameter models are first presented, based on previously published work. All parameters of these circuits can be interpreted as the results of open and short-circuit tests on the transformer. Based on this consideration, numerical procedures are then proposed to derive frequency-dependent lumped parameters from FE simulations. By using an adequate formulation, parameters are directly obtained from the FE model degrees of freedom, without performing any volume integration in post-processing, which can be source of numerical errors. In this contribution, attention is paid on the modeling of magnetic coupling using inductances, and dissipative effects （winding and core losses） using resistances. The impact of conductor eddy currents on the circuit parameters is moreover studied in details. Instead of an analysis of the impact conductor eddy currents may have on the circuit parameters is moreover carried through.展开更多
针对风力助航船舶航线优化中存在的风能利用效率量化不足、油耗预测精度受限以及多目标协同优化机制缺失等问题,提出1种融合动态风帆控制与混合驱动预测的多目标航线优化方法。通过建立基于流体力学特性的动态风帆控制策略模型,实现风...针对风力助航船舶航线优化中存在的风能利用效率量化不足、油耗预测精度受限以及多目标协同优化机制缺失等问题,提出1种融合动态风帆控制与混合驱动预测的多目标航线优化方法。通过建立基于流体力学特性的动态风帆控制策略模型,实现风帆辅助推力的空间矢量解析,该模型突破传统静态攻角设定的局限性,可即时动态调整帆角参数,使风能转化效率处于较高水平。为解决传统物理模型环境适应性差与数据驱动方法物理可解释性弱的双重局限,构建物理约束下的人工神经网络分层融合架构,通过船舶运动学方程构建特征空间基底,采用注意力机制引导的人工神经网络进行残差学习。该方法在保留能耗物理机理的同时,实现数据特征与流体力学方程的双向耦合,经北大西洋航线的验证表明,其油耗预测平均绝对百分比误差(mean absolute percentage error,MAPE)较纯物理模型降低21.9%,较纯数据驱动方法的可解释性也大大提升。在此基础上,建立包含时间成本和燃油消耗的多目标优化模型,设计基于非支配排序遗传算法(non-dominated sorting genetic algorithm,NSGA-Ⅱ)和逼近理想解排序法(technique for order preference by similarity to ideal solution,TOPSIS)的协同优化算法,其非劣解集收敛速度较标准算法得以提升。以“新伊敦”轮为对象的实证研究表明:优化后的航线在北大西洋典型航次中,风帆有效工作效率提升,相较于传统推荐航线,优化航线的单航次航行时间缩短5%左右,油耗成本和固定成本分别降低9.1%和4.95%,总成本降低超过7.2%,有效的提高了风力助航船的经济效益并较少了对环境的污染。展开更多
文摘This paper proposes an improved modularizable high-frequency battery equalizer with multi-winding transformer for energy storage systems. The involvement of parasitic components in circuit resonance, along with the addition of a resonant network, enables soft-switching for the power switches to reduce the switch voltage stress due to high frequency switching operation. The proposed circuit is designed to operate at switching frequency of 1 MHz. The detailed analysis of circuit operation is provided. At last, the feasibility and performance of the proposed battery equalizer are demonstrated through the system implementation and experimental tests of a prototype circuit. Experimental results have shown zero voltage switching (ZVS) is achieved on the switches.
文摘In this paper, equivalent circuits for high frequency multi-winding magnetic components are derived from finite element （FE） computations. Lumped parameter models are first presented, based on previously published work. All parameters of these circuits can be interpreted as the results of open and short-circuit tests on the transformer. Based on this consideration, numerical procedures are then proposed to derive frequency-dependent lumped parameters from FE simulations. By using an adequate formulation, parameters are directly obtained from the FE model degrees of freedom, without performing any volume integration in post-processing, which can be source of numerical errors. In this contribution, attention is paid on the modeling of magnetic coupling using inductances, and dissipative effects （winding and core losses） using resistances. The impact of conductor eddy currents on the circuit parameters is moreover studied in details. Instead of an analysis of the impact conductor eddy currents may have on the circuit parameters is moreover carried through.
文摘针对风力助航船舶航线优化中存在的风能利用效率量化不足、油耗预测精度受限以及多目标协同优化机制缺失等问题,提出1种融合动态风帆控制与混合驱动预测的多目标航线优化方法。通过建立基于流体力学特性的动态风帆控制策略模型,实现风帆辅助推力的空间矢量解析,该模型突破传统静态攻角设定的局限性,可即时动态调整帆角参数,使风能转化效率处于较高水平。为解决传统物理模型环境适应性差与数据驱动方法物理可解释性弱的双重局限,构建物理约束下的人工神经网络分层融合架构,通过船舶运动学方程构建特征空间基底,采用注意力机制引导的人工神经网络进行残差学习。该方法在保留能耗物理机理的同时,实现数据特征与流体力学方程的双向耦合,经北大西洋航线的验证表明,其油耗预测平均绝对百分比误差(mean absolute percentage error,MAPE)较纯物理模型降低21.9%,较纯数据驱动方法的可解释性也大大提升。在此基础上,建立包含时间成本和燃油消耗的多目标优化模型,设计基于非支配排序遗传算法(non-dominated sorting genetic algorithm,NSGA-Ⅱ)和逼近理想解排序法(technique for order preference by similarity to ideal solution,TOPSIS)的协同优化算法,其非劣解集收敛速度较标准算法得以提升。以“新伊敦”轮为对象的实证研究表明:优化后的航线在北大西洋典型航次中,风帆有效工作效率提升,相较于传统推荐航线,优化航线的单航次航行时间缩短5%左右,油耗成本和固定成本分别降低9.1%和4.95%,总成本降低超过7.2%,有效的提高了风力助航船的经济效益并较少了对环境的污染。
