双有源桥（Dual active bridge，DAB）在需要高效能量双向流动的工作场景有广泛的应用。在高开关频率工作时，变换器开关器件结电容充放电时间无法忽略，导致扩展移相控制下DAB零电压开通（zero voltage switching，ZVS）范围断续。通过分析扩展移相控制下双有源桥DC-DC变换器工作模态，建立高开关频率工况下DAB变换器数学模型，提出一种利用磁化电流扩宽ZVS范围的方法。在此基础上，结合电感电流应力优化算法，提出一种适用于高频工况应用的电流应力优化下的软开关控制策略。采用该控制策略，可以有效减小导通损耗，消除开关损耗，显著提升高开关频率下的变换器效率。最后，搭建400KHz实验样机，验证控制策略有效性。
英文摘要:
Dual active bridge (DAB) has a wide range of applications in working scenarios that require efficient two-way flow of energy. At high switching frequency, the charging and discharging time of the junction capacitance of the converter switching devices cannot be ignored. So the range of DAB zero voltage switching (ZVS) under extended phase shift control is intermittent. By analyzing the working modes of dual-active bridge DC-DC converter under extended phase shift control, a mathematical model of DAB converter under high switching frequency is established. And a method of using magnetization current to widen the ZVS range is proposed. On this basis, combined with the inductance current stress optimization algorithm, a soft switch control strategy under current stress optimization suitable for high-frequency operating conditions is proposed. This control strategy can effectively reduce the conduction loss, eliminate the switching loss, and significantly improve the converter efficiency at high switching frequency. Finally, a 400KHz experimental prototype was built to verify the effectiveness of the control strategy.