| 摘要 |
<P>PROBLEM TO BE SOLVED: To minimize a loss in a power factor improvement circuit for driving a motor efficiently by allowing a target DC voltage to be changed to voltage fluctuation in an AC power supply and by setting the target DC voltage to a lower limit within a range, where the power factor improvement circuit operates. <P>SOLUTION: The decision of the target DC voltage is proportional to the voltage value of an AC power supply in addition to the frequency of a compressor 12. The target DC voltage is decided to voltage meeting constraints, where the power factor improvement circuit 4 should operate to fluctuation in a supply voltage and the compressor 12 can be driven without generating any voltage saturation. The target DC voltage is set to the lower limit, where a power factor improvement means can operate, to each voltage value of the AC power supply. <P>COPYRIGHT: (C)2008,JPO&INPIT |
