| 摘要 |
<P>PROBLEM TO BE SOLVED: To almost continuously control the total region of output voltage, while eliminating changes in timbre of magnetic noise, in a two-level inverter for the electric vehicle. <P>SOLUTION: The control unit for the electric vehicle comprises a DC power source and a power converter of two-level converting by a plurality of control modes from DC voltage into three-phase AC phase voltage of variable voltage variable frequency to output a pulse of positive/negative 2 values as the phase voltage. In the control mode, an overmodulation control mode is made to interpose between a pulse width modulation control mode and a one-pulse control mode. The overmodulation control mode lengthens a period of a voltage pulse, gradually toward the zero cross from the peak of an output voltage basic wave in accordance with increasing of output voltage, to additionally continuously change a switching frequency, by switching control asynchronously to a period of the output voltage basic wave, so as to gradually lower the switching frequency according to the increase in the output frequency. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
