Two-transformer three-phase DC-DC resonant converter
A transformer circuit includes a first transformer, a second transformer and an inductor, where a first terminal of the first transformer is coupled to a first terminal of the second transformer. The inductor is coupled between a second terminal of the first transformer and a second terminal of the second transformer.
1. A transformer circuit, comprising:
a first transformer;
a second transformer, a first terminal of the first transformer being coupled to a first terminal of the second transformer;
an inductor coupled between a second terminal of the first transformer and a second terminal of the second transformer; and
a secondary side configured to deliver a three-phase power output using only two transformers, the two transformers comprising the first transformer and the second transformer, and the secondary side comprising:
a first output node formed by a third terminal of the first transformer;
a second output node formed by coupling a fourth terminal of the first transformer and a fourth terminal of the second transformer; and
a third output node formed by a third terminal of the second transformer.
2. The transformer circuit of claim 1 , further comprising a primary side configured to receive a three-phase power input, and the primary side comprising:
a first input node formed by coupling the second terminal of the first transformer and a first terminal of the inductor;
a second input node formed by coupling the first terminal of the first transformer and the first terminal of the second transformer; and
a third input node formed by coupling the second terminal of the second transformer and a second terminal of the inductor.
3. The transformer circuit of claim 2 , wherein the first input node is configured to receive a first phase of the three-phase power input, the second input node is configured to receive a second phase of the three-phase power input, and the third input node is configured to receive a third phase of the three-phase power input.
4. The transformer circuit of claim 2 , wherein the primary side of the transformer circuit is coupled to a resonant tank circuit to receive the three-phase power input.
5. The transformer circuit of claim 4 , wherein the first input node is coupled to a first branch of the resonant tank circuit to receive a first phase of the three-phase power input, the second input node is coupled to a second branch of the resonant tank circuit to receive a second phase of the three-phase power input, and the third input node is coupled to a third branch of the resonant tank circuit to receive a third phase of the three-phase power input.
6. The transformer circuit of claim 1 , wherein the secondary side is coupled to a three-phase rectifier circuit to deliver the three-phase power output, the first output node is coupled to a first branch of the three-phase rectifier circuit, the second output node is coupled to a second branch of the three-phase rectifier circuit, and the third output node is coupled to a third branch of the three-phase rectifier circuit.
7. A resonant converter circuit, comprising:
a resonant tank circuit; and
a transformer circuit coupled to the resonant tank circuit, the transformer circuit comprising:
a first transformer;
a second transformer, a first terminal of the first transformer being coupled to a first terminal of the second transformer;
an inductor coupled between a second terminal of the first transformer and a second terminal of the second transformer, the resonant tank circuit being coupled to a primary side of the transformer circuit; and
a secondary side configured to deliver a three-phase power output using only two transformers, the two transformers comprising the first transformer and the second transformer, and the secondary side comprising:
a first output node formed by a third terminal of the first transformer;
a second output node formed by coupling a fourth terminal of the first transformer and a fourth terminal of the second transformer; and
a third output node formed by a third terminal of the second transformer.
8. The resonant converter circuit of claim 7 , wherein the resonant tank circuit comprises:
a first branch coupled to a first input node of the transformer circuit;
a second branch coupled to a second input node of the transformer circuit; and
a third branch coupled to a third input node of the transformer circuit.
9. The resonant converter circuit of claim 8 , wherein the first branch is coupled between a first input node of the resonant tank circuit and the first input node of the transformer circuit, the second branch is coupled between a second input node of the resonant tank circuit and the second input node of the transformer circuit, and the third branch is coupled between a third input node of the resonant tank circuit and the third input node of the transformer circuit.
10. The resonant converter circuit of claim 9 , wherein the first branch comprises a first branch inductor coupled in series with a first branch capacitor, a first end of the first branch is coupled to the first input node of the transformer circuit, the second branch comprises a second branch inductor coupled in series with a second branch capacitor, a first end of the second branch is coupled to the second input node of the transformer circuit, the third branch comprises a third branch inductor coupled in series with a third branch capacitor, and a first end of the third branch is coupled to the third input node of the transformer circuit.
11. A three-phase resonant direct current-direct current (DC-DC) converter system, comprising:
a primary side;
a secondary side; and
a transformer circuit coupled between the primary side and the secondary side, the transformer circuit comprising:
a first transformer;
a second transformer, a first terminal of the first transformer being coupled to a first terminal of the second transformer,
an inductor coupled between a second terminal of the first transformer and a second terminal of the second transformer; and
a secondary side configured to deliver a three-phase power output using only two transformers, the two transformers comprising the first transformer and the second transformer, and the secondary side comprising:
a first output node formed by a third terminal of the first transformer;
a second output node formed by coupling a fourth terminal of the first transformer and a fourth terminal of the second transformer; and
a third output node formed by a third terminal of the second transformer.
12. The three-phase resonant DC-DC converter system of claim 11 , wherein the primary side comprises a DC voltage input circuit configured to receive a DC input voltage, a resonant tank circuit is coupled to the transformer circuit to provide a three-phase power input to the transformer circuit, and a switching circuit is coupled between the DC voltage input circuit and the resonant tank circuit.
13. The three-phase DC-DC converter system of claim 12 , wherein the secondary side comprises a three-phase rectification circuit coupled between the transformer circuit and a DC voltage output circuit, and the three-phase rectification circuit is configured to receive a three-phase power output signal from the transformer circuit.
14. The three-phase DC-DC converter system of claim 13 , wherein switches in the switching circuit and switches in the three-phase rectification circuit comprise gallium-nitride (GaN) transistors.