| 摘要 |
When a leg is configured by connecting two switching elements having a self-turn-off function in series, a constituent consisting of said leg and a capacitor connected in parallel with said leg is defined as a converter unit, and a constituent consisting of one or more said converter units connected in series is defined as a phase arm, a power conversion device according to one embodiment includes, in each phase of three phases, a positive-side phase arm, a single-phase four-winding transformer, and a negative-side phase arm. In the power conversion device, one end of said positive-side phase arm is connected to the positive side of a secondary winding of said four-winding transformer and the other end thereof to a DC positive side terminal. One end of said negative-side phase arm is connected to the positive side of a tertiary winding of said four-winding transformer and the other end thereof to a DC negative side terminal. The negative sides of the secondary and tertiary windings of said four-winding transformers are connected to each other and also connected between the three phases. The negative sides of the primary windings of said four-winding transformers are connected to each other. The quaternary windings of said four-winding transformers are connected in a delta configuration. The power conversion device is equipped with: first AC breakers connected between the positive sides of the primary windings of said four-winding transformers and a high-voltage AC system; and second AC breakers and inrush current suppression resistors connected in series between the quaternary windings of said four-winding transformers and a low-voltage AC power source. |
