The light rail vehicles (commonly known as tramways or lightly laid railways) offer environmental advantages and have evoked an impressive attraction. The hybrid energy-storage systems efficiently supply energy for the light rail vehicles during the travel. This study implements and analyses an ultracapacitor charger in hybrid energy-storage system for electric-vehicle applications. Moreover, an ultracapacitor charger based on a full-bridge DC–DC converter that utilises a synchronous-rectification technique and high charging-current capability is presented. The proposed converter's current-doubler synchronous rectification reduces the secondary circulating current and recycles the energy of the leakage current to the power-source lead to further increase conversion efficiency. A prototype of this ultracapacitor charger, with an input voltage of 380 V and an output voltage of 14.6 V, has been implemented; the measured efficiency is 92.1% at a full load of 1 kW. In addition, the experimental results show the highest efficiency is 93.4% at an output power of 600 W. Furthermore, an ultracapacitor of 250 F is charged by the presented converter with a charging current of 65 A, and experimental waveforms illustrate that the charging time of the ultracapacitor voltage from 0 to 14.6 V is within 1 min.

中文翻译：

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电动汽车混合动力储能系统中超级电容器充电器的实现与分析

轻轨车辆（通常称为有轨电车或轻轨铁路）具有环保优势，并吸引了众多游客。混合动力储能系统在行驶过程中为轻轨车辆高效供应能量。本研究在电动汽车混合动力储能系统中实现并分析了一种超级电容器充电器。此外，提出了一种基于全桥DC-DC转换器的超级电容器充电器，该充电器利用了同步整流技术和高充电电流能力。提出的转换器的电流倍增器同步整流减少了二次循环电流，并且将泄漏电流的能量再循环到电源引线，从而进一步提高了转换效率。这种超级电容器充电器的原型，已经实现了380 V的输入电压和14.6 V的输出电压；在1 kW的满负载下测得的效率为92.1％。此外，实验结果表明，在输出功率为600 W时，最高效率为93.4％。此外，通过本转换器以250 A的充电电流对250 F的超级电容器进行充电，实验波形表明充电时间从0到14.6 V的超级电容器电压的变化在1分钟内。