| 摘要 |
<P>PROBLEM TO BE SOLVED: To drop voltage linked to DC in a wider range than conventional as well as dropping the output voltage of a converter more than conventional in a low-speed range. <P>SOLUTION: A converter control circuit 9 controls DC/DC conversion for a DC/DC converter 2 so that the voltage linked to DC may be the target voltage value geared to the velocity of an AC motor 5, according to a specified property curve. At this time, the target voltage in the low-speed range where the voltage linked to DC becomes minimum is lower than the output voltage of a DC source 1, so it can improve the switching loss depression effect in a VVVF inverter 4. <P>COPYRIGHT: (C)2007,JPO&INPIT |
