| 摘要 |
In a direct power converter employing a boost chopper, a peak current flowing an inductor of the boost chopper is reduced. When a rectifying duty dr, a discharge duty dc, a voltage between both ends Vc of a capacitor (34), and a rectified voltage Vrec of an AC voltage Vin are introduced, a virtual DC link voltage Vdc in an inverter (6) is expressed by dc€¢Vc+dr€¢Vrec. The discharge duty dc is a time ratio of continuity of a switch (41). The rectifying duty dr has a value obtained by subtracting the discharge duty dc and a zero voltage duty dz from 1. The zero voltage duty dz is a time ratio for the inverter (6) to adopt a zero voltage vector regardless of a magnitude of a voltage to be output from the inverter (6). The capacitor (34) is charged in the boost chopper (3) at a part of a period during which the virtual DC link voltage Vdc is larger than the rectified voltage Vrec. |
