Power conversion apparatus having two secondary winding groups
View Patent ↗A power conversion apparatus including a three-phase transformer interconnected to a three-phase power system, the three-phase transformer including a primary winding group that receives three-phase electric power of the three-phase electric power system, a first secondary winding group and a second secondary winding group that receive electric power transferred from the primary winding group, and a first converter group and a second converter group connected to the first and second secondary winding groups, respectively, the power conversion apparatus further including a DC output terminal group connected to at least one of other ends of the first to third converter arms provided in the first converter group, and connected to at least one of other ends of the fourth to sixth converter arms provided in the second converter group.
1. A power conversion apparatus comprising:
a three-phase transformer interconnected to a three-phase power system;
said three-phase transformer including:
a primary winding group that receives three-phase AC electric power of said three-phase electric power system;
a first secondary winding group and a second secondary winding group that receive the three-phase AC electric power transferred from said primary winding group;
first to third iron cores; and
a first converter group and a second converter group provided for said first and second secondary winding groups, respectively,
said primary winding group having first to third primary windings,
said first secondary winding group having a first neutral point, and having first to third secondary windings having respective one ends star-connected at said first neutral point,
said second secondary winding group having a second neutral point, and having fourth to sixth secondary windings having respective one ends star-connected at said second neutral point,
said first neutral point of said first secondary winding group and said second neutral point of said second secondary winding group being connected to each other,
said first primary winding, said first secondary winding, and said fourth secondary winding being wound around said first iron core,
said second primary winding, said second secondary winding, and said fifth secondary winding being wound around said second iron core,
said third primary winding, said third secondary winding, and said sixth secondary winding being wound around said third iron core,
said first converter group having first to third converter arms having respective one ends connected to other ends of said first to third secondary windings,
said second converter group having fourth to sixth converter arms having respective one ends connected to other ends of said fourth to sixth secondary windings,
said three-phase transformer further including
a positive-side DC output terminal connected with other ends of said first to third converter arms;
a negative-side DC output terminal connected with other ends of said fourth to sixth converter arms; and
a control circuit controlling a DC voltage applied between said positive-side DC output terminal and said negative-side DC output terminal by adjusting a voltage of each of said first to sixth converter arms.
2. The power conversion apparatus according to claim 1 , wherein
each of said first to sixth converter arms has a plurality of unit converters cascade-connected.
3. The power conversion apparatus according to claim 2 , wherein
each of said unit converters includes a full bridge circuit or a bidirectional chopper circuit.
4. The power conversion apparatus according to claim 3 , wherein
each of said unit converters has a DC capacitor for smoothing an output of said full bridge circuit or said bidirectional chopper circuit.