Multi-port charger

A multi-port charger comprising:

• a first bidirectional AC-DC converter, a second bidirectional AC-DC converter, and a third bidirectional AC-DC converter, a positive (+) terminal and a negative (−) terminal of a DC side of each of the first to third bidirectional AC-DC converters being electrically connected to each other;
• at least one decoupling circuit portion connected to the DC side of each of the first to third bidirectional AC-DC converters, the decoupling circuit portion having a topology of a DC-DC converter;
• a first relay configured to determine electrical connection between a voltage application terminal of an AC side of the first bidirectional AC-DC converter and a voltage application terminal of an AC side of the second bidirectional AC-DC converter;
• a second relay configured to determine electrical connection between the voltage application terminal of the AC side of the second bidirectional AC-DC converter and a voltage application terminal of an AC side of the third bidirectional AC-DC converter;
• a third relay configured to determine electrical connection between a neutral end of the AC side of the first bidirectional AC-DC converter and a neutral end of the AC side of the second bidirectional AC-DC converter;
• and
• a controller configured to control operation of the first to third bidirectional AC-DC converters, the decoupling circuit portion, and the first to third relays based on an operating mode, wherein
• the positive (+) terminal and the negative (−) terminal constitute a first DC port and an output end of the decoupling circuit portion and the negative (−) terminal constitute a second DC port having lower voltage than the first DC port,
• the decoupling circuit portion comprises a first switching element having one end connected to the positive (+) terminal, a second switching element having one end connected to the other end of the first switching element and the other end connected to connected to the negative (−) terminal, an inductor having one end connected to a connection node of the first switching element and the second switching element and the other end connected to the output end, and a capacitor having both ends connected to the other end of the inductor and the negative (−) terminal, and
• the decoupling circuit portion further comprises a fourth relay configured to selectively electrically connect one end of the capacitor to one end of the inductor or to a middle point of a secondary coil of a transformer in the third bidirectional AC-DC converter.