| 摘要 |
<p>Provided is a power conversion device which can simultaneously perform regenerative current absorption and direct AC power conversion. A converter (4) is connected to an inverter (6) via a cramp circuit (5). The converter (4) performs commutation in a first commutation mode which compares a trapezoidal wave to a carrier or in a 120-degree electrical connection mode. The cramp circuit (5) has a diode (Dcl) which is short-circuited by a shortcircuit switch (Qcl). When a power factor and a power supply voltage are lowered, the shortcircuit switch (Qcl) makes an electric connection and capacitors (51, 52) of the cramp circuit (5) are connected in series between DC power supply lines (LL, LH). While the shortcircuit switch (Qcl) is electrically connected, the converter (4) performs communication in the 120-degree electrical connection mode instead of the first commutation mode.</p> |
