| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power conversion device that quickly corrects a phase error in a PLL circuit. <P>SOLUTION: The power conversion device includes: an inverter device 2 for driving an AC motor 3; a bypass switch 25 for directly driving the motor; and PLL control means 4. The PLL control means 4 has: phase difference detection means for detecting a phase difference between a detected voltage of a voltage detector 23 and an internal phase of the inverter device 2; PI control means for performing proportional-integral control on the phase difference in a PI controller 43 to produce an uncorrected internal phase via a selector 44; phase correction means for outputting the phase difference via a selector 46 and adding it to the uncorrected internal phase to produce an internal phase; and integral initial value setting means for differentiating the phase difference to produce an integral initial value of the PI controller 43 via a switch 48. A predetermined time after the input of an output switch 24, an input to the selector 44 is switched from 0 to the output of the PI controller 43, an input to the selector 46 is switched from 0 to the phase difference and, shortly after that, returned to 0, and the switch 48 is closed. <P>COPYRIGHT: (C)2013,JPO&INPIT |
