A power converter circuit (3) drives a switching device by the pulse-width modulated wave for converting a direct current into the three phase alternating current.

电力变换器主电路部（3），其根据该脉冲宽度调制波对 开关元件进行驱动，将直流电压转换为三相交流电压；

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The test on three phase alternating voltage has shown that this system has good reliable performances and can afford evidence for finalizing the design of power supply system made in our country.

通过对三相交流电压的测试试验，验证了该系统的可靠性，可为国产电源系统的设计定型提供依据。

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Primary electrical power is provided by two engine driven generators which supply three-phase, 115 volt 400 cycle alternating current.

主电力是由两个发动机驱动发电机供应三相，115伏400周期交流电。

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Although they have not been found to cause any harm, the cables on conventional pylons, which transmit a three-phase alternating current, generate a strong electric field and a continuous buzz of low-frequency radio waves.

ECONOMIST: Monitor