SOFT SWITCHED SINGLE STAGE WIRELESS POWER TRANSFER

• US 20160164346A1
• Filed: 01/26/2016
• Published: 06/09/2016
• Est. Priority Date: 09/25/2014
• Status: Active Grant

• Current Assignee: Navitas Semiconductor Limited (Navitas Semiconductor Corp.)
• Original Assignee: Navitas Semiconductor, Inc.
• Inventors: Zhang, Ju Jason
• Granted Patent: US 10,008,884 B2
• Time in Patent Office: Days
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02M 3/01 Resonant DC/DC converters
• CPC Class Codes: H02M 3/335 using semiconductor devices only
• CPC Class Codes: H02M 3/33571 Half-bridge at primary side of an isolation transformer
• CPC Class Codes: H02M 3/33573 Full-bridge at primary side of an isolation transformer
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

A control scheme and architecture for a wireless electrical energy transmission circuit employs two solid-state switches and a zero voltage switching (ZVS) topology to power an antenna network. The switches drive the antenna network at its resonant frequency and simultaneously energize a separate resonant circuit that has a resonant frequency lower than the antenna circuit. The resonant circuit creates out of phase voltage and current waveforms that enable the switches to operate with (ZVS).

Claims

1. A wireless power transmission circuit comprising:

a voltage source having first and second output terminals;

a first solid-state switch having a pair of first power terminals and a first gate terminal, the pair of first power terminals connected between the first output terminal and a first switch node;

a second solid-state switch having a pair of second power terminals and a second gate terminal, the pair of second power terminals connected between the first switch node and the second output terminal;

a third solid-state switch having a pair of third power terminals and a third gate terminal, the pair of third power terminals connected between the first output terminal and a second switch node;

a fourth solid-state switch having a pair of fourth power terminals and a fourth gate terminal, the pair of fourth power terminals connected between the second switch node and the second output terminal;

an antenna network coupled between the first switch node and the second switch node, and configured to transmit electrical energy at a first frequency; and

a controller coupled to the first, second, third and fourth gate terminals and configured to operate the first, second, third and fourth solid-state switches such that they each operate at a fixed duty cycle and regulate power from the voltage source to the antenna network by changing a phase delay between two or more of the first, second, third and fourth solid-state switches.

2. The wireless power transmission circuit of claim 1 wherein in a first portion of a switching cycle the first and second solid-state switches operate complementary and in a second portion of the switching cycle the third and fourth solid-state switches operate complementary.

3. The wireless power transmission circuit of claim 2 wherein zero voltage switching is performed in a deadtime located between the first portion of the switching cycle and the second portion of the switching cycle.

4. The wireless power transmission circuit of claim 1 wherein the power from the voltage source is regulated by changing a phase delay between the first and the third solid-state switches.

5. The wireless power transmission circuit of claim 1 wherein the first, second, third and fourth solid-state switches operate at a fixed duty cycle of 50 percent.

6. The wireless power transmission circuit of claim 1 wherein the first, second, third and fourth solid-state switches are GaN-based devices.

7. The wireless power transmission circuit of claim 1 wherein the first, second, third and fourth solid-state switches operate at a switching frequency in a range of 1-20 MHz.

8. The wireless power transmission circuit of claim 1 wherein the first, second, third and fourth solid-state switches are configured to operate with a voltage potential in the range of 50-1000 Volts DC.

9. The wireless power transmission circuit of claim 1 further comprising a first resonant circuit configured to resonate at a second frequency and is coupled between the first switch node and the antenna network.

10. The wireless power transmission circuit of claim 9 further comprising an AC voltage divider circuit coupled to the first resonant circuit and configured to reduce an AC voltage supplied the antenna network.

11. The wireless power transmission circuit of claim 10 further comprising an impedance matching circuit coupled to the AC voltage divider circuit and configured to match an impedance of the antenna network.

12. The wireless power transmission circuit of claim 9 further comprising a second resonant circuit coupled between the first switch node and the second output terminal;

and

a third resonant circuit coupled between the second switch node and the second output terminal.

13. The wireless power transmission circuit of claim 9 further comprising a second resonant circuit coupled in parallel with the first resonant circuit.

14. A wireless power transmission circuit comprising:

a voltage source;

a full-bridge coupled to the voltage source and having first, second, third and fourth solid-state switches;

an antenna network coupled to the full-bridge rectifier and configured to transmit electrical energy at a first frequency; and

a controller coupled to the first, second, third and fourth solid-state switches and configured to regulate power from the voltage source to the antenna network by changing a phase delay between two or more of the first, second, third and fourth solid-state switches.

15. The wireless power transmission circuit of claim 14 wherein in a first portion of a switching cycle the first and second solid-state switches operate complementary and in a second portion of a switching cycle the third and fourth solid-state switches operate complementary.

16. The wireless power transmission circuit of claim 15 wherein zero voltage switching is performed in a deadtime located between the first portion of the switching cycle and the second portion of the switching cycle.

17. The wireless power transmission circuit of claim 14 wherein the first, second, third and fourth solid-state switches operate at a fixed duty cycle.

18. The wireless power transmission circuit of claim 17 wherein the fixed duty cycle is approximately 50 percent.

19. The wireless power transmission circuit of claim 14 wherein the phase delay is changed between the first and the third solid-state switches.

20. The wireless power transmission circuit of claim 14 wherein the first, second, third and fourth solid-state switches change state with zero voltage switching.

21. A method of operating a wireless power transmission circuit, the method comprising:

supplying power to the power transmission circuit with a voltage source;

coupling power from the voltage source to the transmission circuit with a full-bridge comprising first, second, third and fourth solid-state switches;

regulating power to the power transmission circuit with a controller configured to change the power supplied to the power transmission circuit by changing the phase delay between two or more of the first, second, third and fourth solid-state switches.

22. The method of claim 21 wherein in a first portion of a switching cycle the first and second solid-state switches operate complementary and in a second portion of the switching cycle the third and fourth solid-state switches operate complementary.

23. The method of claim 22 wherein zero voltage switching is performed in a deadtime located between the first portion of the switching cycle and the second portion of the switching cycle.

24. The method of claim 21 wherein the first, second, third and fourth solid-state switches operate at a fixed duty cycle.

25. The method of claim 24 wherein the fixed duty cycle is 50 percent.

26. The method of claim 21 wherein the phase delay is changed between the first and the third solid-state switches.

27. The method of claim 21 wherein the first, second, third and fourth solid-state switches change state with zero voltage switching.