Approach for DC to AC inversion
Aspects of the disclosure include a power-conversion system including an input, an output, a DC/DC converter coupled to the input, a DC/AC inverter coupled to the DC/DC converter and coupled to the output, and at least one controller coupled to the DC/DC converter and the DC/AC inverter, the at least one controller being configured to control the DC/DC converter to draw input power from the input and provide converted power to the DC/AC inverter, and control the DC/AC inverter to receive the converted power and provide output power to the output in synchronization with the DC/DC converter drawing the input power from the input.
1. A power-conversion system comprising:
an input;
an output;
a DC/DC converter coupled to the input, wherein the DC/DC converter includes converter switches coupled to the input;
a DC/AC inverter coupled to the DC/DC converter and coupled to the output, wherein the DC/AC inverter includes inverter switches coupled to the output; and
at least one controller coupled to the DC/DC converter and the DC/AC inverter, the at least one controller being configured to
control the DC/DC converter based on a carrier signal having a carrier-signal frequency to draw input power from the input and provide converted power to the DC/AC inverter,
control the DC/AC inverter to receive the converted power and provide output power to the output in synchronization with the DC/DC converter drawing the input power from the input, wherein controlling the DC/AC inverter to provide the output power to the output in synchronization with the DC/DC converter drawing the input power from the input includes controlling the DC/AC inverter based on the carrier signal having the carrier-signal frequency,
control the DC/DC converter switches based on a comparison between a first reference signal and the carrier signal, and
control the DC/AC inverter switches based on a comparison between a second reference signal and the carrier signal,
wherein the at least one controller is further configured to control the DC/DC converter switches to provide power to the DC/AC inverter switches in synchronization with controlling the DC/AC inverter switches to draw power from the DC/DC converter switches.
2. The power-conversion system of claim 1 , wherein the at least one controller is further configured to control at least two converter switches of the converter switches and at least two inverter switches of the inverter switches to be in a closed and conducting position approximately simultaneously.
3. The power-conversion system of claim 1 , wherein the DC/DC converter includes a transformer having a primary winding coupled to the converter switches and a secondary winding coupled to the inverter switches.
4. The power-conversion system of claim 3 , wherein the at least one controller is further configured to
control at least two converter switches of the converter switches to conduct power from the input to the primary winding, and
control at least two inverter switches of the inverter switches to conduct power from the secondary winding to the output.
5. The power-conversion system of claim 1 , further comprising:
a positive DC bus and a negative DC bus coupled between the DC/DC converter and the DC/AC inverter; and
a capacitor coupled between the positive DC bus and the negative DC bus.
6. The power-conversion system of claim 5 , wherein the at least one controller is further configured to control the DC/AC inverter to receive the converted power directly from the DC/DC converter, bypassing the capacitor.
7. The power-conversion system of claim 5 , wherein the capacitor has a capacitance of approximately 50 μF or less.
8. The power-conversion system of claim 5 , further comprising an output inductor coupled to the capacitor via the DC/AC inverter and coupled to the output.
9. The power-conversion system of claim 8 , wherein the at least one controller is further configured to control the DC/AC inverter to discharge the output inductor to the capacitor.
10. The power-conversion system of claim 8 , wherein the at least one controller is further configured to control the DC/AC inverter to discharge the capacitor to the output inductor.
11. The power-conversion system of claim 1 , wherein the first reference signal and the second reference signal have a same magnitude and a same frequency, and are phase-shifted by 180 degrees with respect to one another.
12. A non-transitory computer-readable medium storing thereon sequences of computer-executable instructions for operating a power-conversion system having an input, an output, a DC/DC converter coupled to the input, a DC/AC inverter coupled to the DC/DC converter and to the output, wherein the DC/DC converter includes converter switches coupled to the input, and wherein the DC/AC inverter includes inverter switches coupled to the output, the sequences of computer-executable instructions including instructions that instruct at least one processor to:
control the DC/DC converter based on a carrier signal having a carrier-signal frequency to draw input power from the input and provide converted power to the DC/AC inverter,
control the DC/AC inverter to receive the converted power and provide output power to the output in synchronization with the DC/DC converter drawing the input power from the input, wherein controlling the DC/AC inverter to provide the output power to the output in synchronization with the DC/DC converter drawing the input power from the input includes controlling the DC/AC inverter based on the carrier signal having the carrier-signal frequency,
control the DC/DC converter switches based on a comparison between a first reference signal and the carrier signal,
control the DC/AC inverter switches based on a comparison between a second reference signal and the carrier signal, and
control the DC/DC converter switches to provide power to the DC/AC inverter switches in synchronization with controlling the DC/AC inverter switches to draw power from the DC/DC converter switches.
13. The non-transitory computer-readable medium of claim 12 , wherein the DC/DC converter includes at least two converter switches and the DC/AC inverter includes at least two inverter switches, and wherein the instructions further instruct at least one processor to:
control the at least two converter switches to provide power to the at least two inverter switches in synchronization with controlling the at least two inverter switches to draw power from the at least two converter switches.
14. The non-transitory computer-readable medium of claim 13 , wherein the instructions further instruct at least one processor to control the at least two converter switches and the at least two inverter switches to be in a closed and conducting position approximately simultaneously.
15. The non-transitory computer-readable medium of claim 13 , wherein the DC/DC converter includes a transformer having a primary winding and a secondary winding,
wherein controlling the at least two converter switches to provide power to the at least two inverter switches includes controlling the at least two converter switches to provide power to the primary winding, and
wherein controlling the at least two inverter switches to receive the converted power and provide output power to the output in synchronization with the DC/DC converter drawing the input power from the input includes controlling the at least two inverter switches to conduct power from the secondary winding to the output.
16. The non-transitory computer-readable medium of claim 12 , wherein the power-conversion system further includes a positive DC bus and a negative DC bus coupled between the DC/DC converter and the DC/AC inverter, and a capacitor coupled between the positive DC bus and negative DC bus, and wherein the instructions further instruct at least one processor to control the DC/AC inverter to receive the converted power directly from the DC/DC converter, bypassing the capacitor.
17. The non-transitory computer-readable medium of claim 12 , wherein the power-conversion system further includes a capacitor coupled to the DC/AC inverter and an output inductor coupled to the capacitor via the DC/AC inverter and to the output, wherein the instructions further instruct at least one processor to control the DC/AC inverter to discharge the output inductor to the capacitor.
18. The non-transitory computer-readable medium of claim 12 , wherein the power-conversion system further includes a capacitor coupled to the DC/AC inverter and an output inductor coupled to the capacitor via the DC/AC inverter and to the output, wherein the instructions further instruct at least one processor to control the DC/AC inverter to discharge the capacitor to the output inductor.
19. A method of operating a power-conversion system having an input, an output, a DC/DC converter coupled to the input, a DC/AC inverter coupled to the DC/DC converter and to the output, wherein the DC/DC converter includes converter switches coupled to the input, and wherein the DC/AC inverter includes inverter switches coupled to the output, the method comprising:
controlling the DC/DC converter based on a carrier signal having a carrier-signal frequency to draw input power from the input and provide power to the DC/AC inverter;
controlling the DC/AC inverter to receive the converted power and provide output power to the output in synchronization with the DC/AC inverter drawing power from the DC/DC converter, wherein controlling the DC/AC inverter to receive the converted power and provide the output power to the output in synchronization with the DC/AC inverter drawing power from the DC/DC converter includes controlling the DC/AC inverter based on the carrier signal having the carrier-signal frequency;
controlling the DC/DC converter switches based on a comparison between a first reference signal and the carrier signal; and
controlling the DC/AC inverter switches based on a comparison between a second reference signal and the carrier signal,
wherein controlling the DC/DC converter switches to provide power to the DC/AC inverter switches is in synchronization with controlling the DC/AC inverter switches to draw power from the DC/DC converter switches.