The motor is powered by high voltage DC supply and the current from the fuel cell system is regulated via a DC DC converter.

发动机采用高压直流电驱动，电流转换通过直流-直流转换器实现。

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Some people, however, question that standard because over long distances high-voltage DC lines suffer lower losses than AC.

现在有人开始质疑这一标准的适用性，因为在远距离输电的情况下，采用高压直流(HVDC)要比高压交流损耗小。

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An electrical power transformer that converts 220-250 volts AC current to high voltage DC.

一个把220 ~ 250伏交流电转化成高压直流电的变压器。

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High-voltage DC can carry power over long distances at lower cost than alternating current, but the transformers still cost too much to make the idea widespread.

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It's high-voltage, high-current DC, which is not too far off of automotive electronics from a technology standpoint.

CNN: Transcript of June 'CNN Money Summit: Money & Main St.'