Method and apparatus for detecting load fluctuation of wireless power transmission

• US 9,350,193 B2
• Filed: 05/31/2012
• Issued: 05/24/2016
• Est. Priority Date: 06/01/2011
• Status: Expired due to Fees

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Nam Yun, Kwon, Sang Wook, Park, Yun Kwon, Park, Eun Seok, Hong, Young Tack, Kim, Ki Young, Ryu, Young Ho, Kim, Dong Zo, Choi, Jin Sung, Yoon, Chang Wook
• Primary Examiner(s): Tran, Thienvu
• Assistant Examiner(s): Inge, Joseph
• Application Number:
  US13/484,422
• Publication Number:
  US 20120306269A1
• Time in Patent Office: 1,454 Days
• Field of Search: 307/11, 307/104
• US Class Current: 1/1
• CPC Class Codes: B60L 2210/10 DC to DC converters
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 53/126 Methods for pairing a vehicle and a charging station, e.g. establishing a one-to-one relation between a wireless power transmitter and a wireless power receiver
• CPC Class Codes: B60L 53/36 by positioning the vehicle
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 7/00304 Overcurrent protection
• CPC Class Codes: H02J 7/00308 Overvoltage protection
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility
• CPC Class Codes: Y02T 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles

Abstract

A method and apparatus to detect load fluctuation of a wireless power transmission are provided. A wireless power transmitter includes a resonator configured to wirelessly transmit, to a target device, an output power. The wireless power transmitter further includes a power detector configured to detect a current of the output power. The wireless power transmitter further includes a controller configured to detect a change in the current, and to detect a target load based on the change in the current. The target load includes a load of which the output power is applied thereto.

Claims

1. A wireless power transmitter comprising:

a resonator configured to wirelessly transmit, to a target device, an output power;

a power detector configured to detect a current of the output power; and

a controller configured to

detect a change in the current,

detect a target load based on the change in the current,

receive, from the target device, information on a received power, and

determine a charging mode of the target device based on the information;

wherein an operation mode of the wireless power transmitter is selected from a plurality of operation modes comprising a standby mode, a connection mode, and a charging control mode,

wherein the charging mode is selected from a plurality of charging modes comprising a constant current (CC) mode and a constant voltage (CV) mode, and

wherein the controller receives the information in the charging control mode, and adjusts the output power based on the charging mode.

2. The wireless power transmitter of claim 1, wherein the controller is further configured to determine the output power.

3. The wireless power transmitter of claim 1, further comprising:

a power converter configured to output the output power.

4. The wireless power transmitter of claim 3, wherein the load is applied to an output of the power converter.

5. The wireless power transmitter of claim 3, further comprising:

a power supply configured to apply, to the power converter, a voltage based on a control of the controller.

6. The wireless power transmitter of claim 1, wherein the controller is further configured to determine a state of a wireless power transmission based on the target load.

7. The wireless power transmitter of claim 1, wherein, when the current is less than a predetermined value, the controller is further configured to terminate a charging of the target device.

8. The wireless power transmitter of claim 1, wherein the controller is further configured to adjust the output power based on the target load.

9. The wireless power transmitter of claim 1, wherein the target load comprises a sum of loads of target devices.

10. The wireless power transmitter of claim 1, wherein the power detector comprises:

a first resistor in which the current flows; and

a comparator configured to output, to the controller, voltages applied to a first terminal and a second terminal of the first resistor,

wherein the controller is further configured to detect the target load based on the voltages and a resistance value of the first resistor.

11. The wireless power transmitter of claim 10, further comprising:

a power converter configured to output the output power,

wherein the power detector further comprises

a second resistor comprising a first terminal and a second terminal, the first terminal being connected to the first terminal of the first resistor, and the second terminal being connected to a positive terminal of the comparator, and

a third resistor comprising a first terminal and a second terminal, the first terminal being connected to the second terminal of the first resistor and an input of the power converter, and the second terminal being connected to a negative terminal of the comparator.

12. A method of detecting a load in a wireless power transmission, comprising:

wirelessly transmitting, to a target device, an output power;

detecting a current of the output power;

detecting a change in the current;

detecting a target load based on the change in the current;

receiving, from the target device, information on a received power;

determining a charging mode of the target device based on the information; and

wherein an operation mode of the wireless power transmitter is selected from a plurality of operation modes comprising a standby mode, a connection mode, and a charging control mode,

wherein the charging mode is selected from a plurality of charging modes comprising a constant current (CC) mode and a constant voltage (CV) mode, and

wherein the controller receives the information in the charging control mode, and adjusts the output power based on the charging mode.

13. The method of claim 12, further comprising:

determining a state of the wireless power transmission based on the target load.

14. The method of claim 12, further comprising, when the current is less than a predetermined value, terminating a charging of the target device.

15. The method of claim 12, further comprising adjusting the output power based on the target load.

16. The method of claim 12, wherein the target load further comprises a sum of loads of target devices.

17. The method of claim 12, further comprising:

matching an impedance and a resonant frequency of a source device to an impedance and a resonant frequency of the target device.

18. A non-transitory computer-readable storage medium storing a program comprising instructions to cause a computer to implement the method of claim 12.