Resonant DC-DC converter

A resonant DC-DC converter circuit comprising:

• a first input node, a second input node, and a third input node, each of the first, second and third input nodes configured to receive one phase of a three phase input power;
• a delta circuit comprising a first leg connected between a first corner node and a second corner node, a second leg connected between the second corner node and a third corner node, and a third leg connected between the third corner node and the first corner node;
• and
• a first outer resonant device connected between the first input node and the first corner node;
• a second outer resonant device connected between the second input node and the second corner node;
• and a third outer resonant device connected between the third input node and the third corner node,
• wherein the first leg consists of a first inner resonant device and a first transformer, the first inner resonant device is connected in series between the first corner node and the first transformer, the second leg consists of a second inner resonant device and a second transformer, the second inner resonant device is connected in series between the second corner node and the second transformer, and the third leg consists of a third inner resonant device and a third transformer, the third inner resonant device is connected in series between the third corner node and the third transformer.