Contactless power transfer system and method for controlling the same

Patent metadata

Field	Value
Publication number	US-11303156-B2
Application number	US-201615375789-A
Country	US
Kind code	B2
Filing date	Dec 12, 2016
Priority date	Dec 18, 2015
Publication date	Apr 12, 2022
Grant date	Apr 12, 2022

Abstract

A contactless power transfer system is provided. The contactless power transfer system includes a first power exchanger coil configured to exchange power. The contactless power transfer system also includes a first power converter operatively coupled to the first power exchanger coil and configured to convert a direct current power to an alternating current power at a system frequency. The contactless power transfer system further includes a controller configured to control an operating state of the first power converter to vary an alternating current power provided to the first power exchanger coil at the system frequency.

First claim

What is claimed is:

1. A method for contactless power transfer, the method comprising:
operating a first power exchanger coil at a system frequency, the first power exchanger coil capable of transferring alternating current power to a second power exchanger coil of a wireless power receiving device via a magnetic field using a resonance based coupling at the system frequency;
determining a power requirement associated with a load of the wireless power receiving device;
controlling a duration of intermittent time periods of an activated state to generate pulses of alternating current power at the system frequency based on the load and the power requirement associated with the load, wherein the activated state is different from a deactivated state in which the first power exchanger coil does not transfer the alternating current power; and
transferring, during each of the intermittent time periods, the alternating current power from the first power exchanger coil to the second power exchanger coil via the magnetic field using the resonance based coupling at the system frequency.

2. The method of claim 1 , wherein determining the power requirement associated with the load of the wireless power receiving device includes receiving at least a voltage measured at a first node located between the second power exchanger coil and the load, and varying the duration of the intermittent time periods based, at least in part, on the voltage.

3. The method of claim 1 , wherein detecting the second power exchanger coil comprises generating a bias power using the first power converter and transmitting the bias power from the first power exchanger coil to the second power exchanger coil.

4. The method of claim 3 , further comprising receiving the bias power from the first power exchanger coil using a second bias processing unit and transmitting a signal representative of a presence of the second power exchanger coil to a controller.

5. A contactless power transfer system comprising:
a power converter configured to generate, during an activated state, an alternating current power at a system frequency based, at least in part, on a direct current power received from a power source;
a first power exchanger coil operatively coupled with the power converter and configured to receive the alternating current power from the power converter, the first power exchanger coil configured to transfer the alternating current power to a second power exchanger coil of a wireless power receiving device using resonance based coupling via a magnetic field at the system frequency; and
a controller operatively coupled with the power converter and configured to:
determine a power requirement associated with a load of the wireless power receiving device; and
control a duration of intermittent time periods of an activated state to generate pulses of alternating current power at the system frequency based on the load and the power requirement associated with the load, wherein the activated state is different from a deactivated state in which the first power exchanger coil does not transfer the alternating current power.

6. The contactless power transfer system of claim 5 , further comprising a first bias processing unit operatively coupled to the controller, wherein the first bias processing unit is configured to provide an operating power to the controller from the power source.

7. The contactless power transfer system of claim 5 , further comprising a second bias processing unit operatively coupled to the second power exchanger coil and configured to receive a bias power transmitted by the first power exchanger coil and transmitting a signal representative of a detected second power exchanger coil to the controller.

8. The contactless power transfer system of claim 7 , further comprising a bias coil operatively coupled to the second power exchanger coil and the second bias processing unit, and wherein the bias coil is configured to receive the bias power from the first power exchanger coil and transmit the bias power to the second bias processing unit for detecting the second power exchanger coil.

9. The contactless power transfer system of claim 7 , further comprising a bias transformer configured to receive the bias power from the first power exchanger coil and transmit the bias power to the second bias processing unit for detecting the second power exchanger coil, wherein a primary winding of the bias transformer is operatively coupled to the second power exchanger coil and a secondary winding of the bias transformer is operatively coupled to the second bias processing unit.

10. The contactless power transfer system of claim 7 , wherein the second bias processing unit is a switched-mode power supply.

11. The contactless power transfer system of claim 5 , wherein the controller is further configured to determine the power requirement associated with the load of the wireless power receiving device by receiving a voltage measured between a node located between the second power exchanger coil and the load, and to vary the duration of the intermittent time periods based, at least in part, on the voltage.

12. The contactless power transfer system of claim 5 , wherein each intermittent time period of the activated state is followed by a time period of the deactivated state, and wherein the time period of the activated state is different than the time period of the deactivated state.

13. The method of claim 1 , wherein each intermittent time period of the activated state is followed by a time period of the deactivated state, and wherein the time period of the activated state is different than the time period of the deactivated state.

14. The method of claim 1 further comprising:
modifying the duration of the intermittent time periods in response to a change in a power requirement associated with the second power exchanger coil.

15. The method of claim 13 , wherein controlling the duration of the of intermittent time periods is different from a duty cycle associated with duty cycle modulation.

16. The method of claim 1 , wherein the operating state comprises an activated state and a deactivated state of the first power converter and the controller is configured to control a first time period of the activated state of the first power converter and a second time period of the deactivated state of the first power converter.

17. The method of claim 1 , wherein controlling the duration of the intermittent time periods of the activated state results in an average of the pulses of the alternating current power generated by the first power converter.

18. The contactless power transfer system of claim 5 , wherein controlling the duration of the intermittent time periods of the activated state results in an average of the pulses of the alternating current power generated by the first power converter.

Assignees

• Gen Electric

Inventors

• Vijayan Pradeep
• Naik Rajendra
• Raghunathan Arun Kumar
• Mahadeva Iyer Vishnu

Classifications

• H02J50/80

  involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices · CPC title

• H02J50/12 Primary

  of the resonant type · CPC title

• H02J50/10 Primary

  using inductive coupling · CPC title

• H02J50/90

  involving detection or optimisation of position, e.g. alignment · CPC title

• H02J7/025

  Electricity · mapped topic