| 摘要 |
A power converter is provided with first to fourth IGBTs (3-6) connected between the positive and negative potentials of DC voltage sources (1 and 2), an AC output terminal (11) led out from the connecting point P2 of the IGBTs (4 and 5), a coupling diode (12) connected between the connecting point P1 of the IGBTs (3 and 4) and the intermediate potential point P4 of the DC power sources, a coupling diode (13) connected between the connecting point P3 of the IGBTs (5 and 6) and the point P4, a capacitor (41) and diode (42) connected between the anode of the diode (12) and the cathode of the IGBT (4), and a discharging resistor (43) connected between the connecting point of the capacitor (41) and the diode (42) and the negative potential side of the DC voltage sources. A snubber circuit for the IGBT (4) is constituted of a small number of parts. The surge voltage when the IGBT (4) is turned off is suppressed by clamping the voltage across both ends of the capacitor (41) to the half of the voltage between the positive and negative sides of the DC voltage sources. |
