Patent ID: 9722507
Date: 2017-08-01
CPC Classifications: H02M

Claim:
1. An electric power conversion apparatus configured to convert electric power from DC or AC to AC or DC, wherein when a constituent element constituted of a leg in which two switching elements provided with self-arc-extinguishing capability are connected in series, and a capacitor connected in parallel with the leg is made a converter unit, and a constituent element formed by connecting one or more converter units in series is made a phase arm, a phase arm on the positive side, a single-phase four-winding transformer, and a phase arm on the negative side are included in each of three phases, one end of the phase arm on the positive side is connected to the positive side of a secondary winding of the four-winding transformer, and the other end thereof is connected to a DC positive side terminal, one end of the phase arm on the negative side is connected to the positive side of a tertiary winding of the four-winding transformer, and the other end thereof is connected to a DC negative side terminal, the negative sides of the secondary windings and the negative sides of the tertiary windings of the four-winding transformers are connected to each other, and are connected to each other between the three phases, the negative sides of the primary windings of the four-winding transformers are connected to each other, quartic windings of the four-winding transformers are connected to each other in series to form delta connection, the electric power conversion apparatus comprising: a first AC circuit breaker connected between the positive sides of the primary windings of the four-winding transformers, and a high-voltage AC power system; and a second AC circuit breaker, and rush current suppression resistors connected in series between the quartic windings of the four-winding transformers, and a low-voltage AC power supply.