| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a grid-connected inverter device wherein the distortion of an output current and a switching loss can be suppressed even though an output voltage of a booster circuit is fluctuated by fluctuation in system voltage. <P>SOLUTION: A boosting control unit 9 includes: a first voltage ratio computation unit 14 that determines a ratio of an effective value of a system voltage to a rated value of a system voltage; and a first multiplication unit 16 that multiplies the result of this computation by a preset command value of a direct-current output voltage. The boosting control unit carries out feedback control by the output voltage of the booster circuit 6 with the output value of the first multiplication unit 16 as target value. An inverter control unit 10 includes: a second voltage ratio computation unit 27 that computes a ratio of an instantaneous value of a system voltage to the output voltage of the booster circuit; a second multiplication unit 28 that multiplies the value computed by the second voltage ratio computation unit 27 by a preset constant; and an addition unit 29 that adds the value computed by the second multiplication unit 28 to the output value of a PI computation unit 18. The inverter control unit generates a control signal for an inverter circuit 7 based on the value computed by the addition unit 29. <P>COPYRIGHT: (C)2008,JPO&INPIT |
