| 摘要 |
<p>In three-phase, three-level conversion circuits, there is a method whereby a fuse is inserted in each phase arm, as a protective circuit against element malfunction, however fuses are large and expensive, and wiring inductance and loss are increased. An opening means is provided that electrically opens on the positive electrode side or negative electrode side of each phase arm through which the main current for a semiconductor switch or a diode flows, or one terminal side of a bidirectional semiconductor switch, and the malfunctioning element is disconnected from the DC power supply, in order to continue operation during semiconductor element malfunction in a three-level power conversion circuit using the bidirectional semiconductor switch. This opening means is a structural technique based on an active action using detection of a power supply short-circuit current and an action utilizing physical change from overheating.</p> |
