| 摘要 |
Provided is a technique of reducing power capacity required for a charge and discharge circuit. A converter (3) performs full-wave rectification on a single-phase voltage (Vin), thus outputting a rectified voltage (Vrec) across DC power supply lines (LL, LH). An inverter (5) receives the rectified voltage (Vrec) and then supplies a three-phase AC current (Iu, Iv, Iw) to an inductive load (6). Between the DC power supply lines (LL, LH) is connected a charge and discharge circuit (4). The charge and discharge circuit (4) includes a buffer circuit (4a) and a boost circuit (4b). The buffer circuit (4a) includes a series connection between a capacitor (C4) and a switch (Sc). The boost circuit (4b), which may be configured by a boost chopper, includes a switch (SI), a reactor (L4) and a diode (D40). The charge and discharge circuit (4) provides and receives part of pulsations of the power input to the converter (3) between the DC power supply lines (LL, LH). |
