Wireless power transmitting device and method of controlling the same

• US 10,491,040 B2
• Filed: 11/13/2017
• Issued: 11/26/2019
• Est. Priority Date: 02/06/2017
• Status: Active Grant

• Current Assignee: Wit Co., Ltd.
• Original Assignee: WITS Company Limited
• Inventors: Kim, Young Ho
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): Pham, Duc M
• Application Number:
  US15/810,736
• Publication Number:
  US 20180226833A1
• Time in Patent Office: 743 Days
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02M 1/0048 Circuits or arrangements for reducing losses using snubbers H02M1/34
• CPC Class Codes: H02M 1/0058 by employing soft switching techniques, i.e. commutation of transistors when applied voltage is zero or when current flow is zero using an auxiliary actively switched resonant commutation circuit connected to an intermediate DC voltage or between two push-pull branches of an inverter bridge H02M7/4811; in resonant inverters H02M7/4815; in inverters operating from a resonant DC source H02M7/4826
• CPC Class Codes: H02M 1/0064 Magnetic structures combining different functions, e.g. storage, filtering or transformation
• CPC Class Codes: H02M 1/007 Plural converter units in cascade push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826
• CPC Class Codes: H02M 1/32 Means for protecting converters other than automatic disconnection
• CPC Class Codes: H02M 3/155 using semiconductor devices only
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators
• CPC Class Codes: H02M 3/3376 with automatic control of output voltage or current
• CPC Class Codes: H02M 7/5387 in a bridge configuration
• 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 wireless power transmitting device includes a wireless power generator configured to generate a wireless power based on a supplied power of a power source; a wireless power transmitter configured to transmit the wireless power to a receiving device in a wireless manner; a detector configured to detect either one or both of a voltage and a current of the wireless power transmitter; a distance calculator configured to calculate a distance from the wireless power transmitting device to the receiving device based on either one or both of the voltage and the current of the wireless power transmitter; a comparator configured to: compare a reference efficiency corresponding to the distance to a power transmission efficiency, and generate information of a transmission state based on a result of the comparison; and a controller configured to control the wireless power generator depending on an operation mode corresponding to the information of the transmission state.

Claims

1. A wireless power transmitting device, comprising:

a wireless power generator configured to generate a wireless power based on a supplied power of a power source;

a wireless power transmitter configured to transmit the wireless power to a receiving device in a wireless manner;

a detector configured to detect either one or both of a voltage and a current of the wireless power transmitter;

a distance calculator configured to calculate a distance from the wireless power transmitting device to the receiving device based on either one or both of the voltage and the current of the wireless power transmitter;

a comparator configured to;

compare a reference efficiency corresponding to the distance to a power transmission efficiency, and

generate information of a transmission state based on a result of the comparison; and

a controller configured to control the wireless power generator depending on an operation mode corresponding to the information of the transmission state.

2. The wireless power transmitting device of claim 1, wherein the controller is configured to:

set the operation mode to a first operation mode in response to the power transmission efficiency being equal to or higher than the reference efficiency;

set the operation mode to a second operation mode in response to the power transmission efficiency being lower than the reference efficiency; and

control the wireless power generator such that a magnitude of the wireless power generated in response to the second operation mode being set is lower than a magnitude of the wireless power generated in response to the first operation mode being set.

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

a demodulator configured to;

receive a packet signal comprising information of a magnitude of a received power of the receiving device; and

generate the information of the magnitude of the received power by demodulating the packet signal.

4. The wireless power transmitting device of claim 3, further comprising:

a power calculator configured to calculate a magnitude of the supplied power of the power source based on a voltage and a current of the power source,

wherein the comparator is configured to calculate the power transmission efficiency based on the magnitude of the supplied power and the magnitude of the received power, and

wherein the detector further is configured to detect a voltage and a current of the power source.

5. The wireless power transmitting device of claim 1, wherein:

the wireless power transmitter comprises a transmission coil configured to be electromagnetically coupled to the receiving device; and

the voltage of the wireless power transmitter is a voltage of the transmission coil.

6. The wireless power transmitting device of claim 5, wherein the distance calculator is configured to calculate the distance such that the distance calculated if the voltage is a first voltage is longer than the distance calculated if the voltage is a second voltage lower than the first voltage.

7. The wireless power transmitting device of claim 5, wherein the comparator is configured to:

in response to the voltage being a first voltage, determine the distance to be a first distance; and

in response to the voltage being a second voltage lower than the first voltage, determine the distance to be a second distance shorter than the first distance.

8. The wireless power transmitting device of claim 1, wherein the comparator is configured to determine the reference efficiency based on the distance.

9. The wireless power transmitting device of claim 8, wherein the comparator is configured to determine the reference efficiency such that the reference efficiency determined if the distance is a first distance is lower than the reference efficiency determined if the distance is a second distance shorter than the first distance.

10. The wireless power transmitting device of claim 8, wherein the comparator is configured to:

in response to the distance being a first distance, determine the reference efficiency to have a first magnitude; and

in response to the distance being a second distance longer than the first distance, determine the reference efficiency to have a second magnitude less than the first magnitude.

11. The wireless power transmitting device of claim 1, wherein the controller is configured to:

determine a switching frequency of the wireless power generator based on the distance; and

transmit a control signal of the switching frequency to the wireless power generator.

12. The wireless power transmitting device of claim 1, wherein the wireless power generator comprises:

a DC-DC converter comprising a first switch, and configured to convert a DC voltage of the power source through an on-off operation of the first switch and generate conversion power; and

an inverter comprising a second switch and a third switch, and configured to generate the wireless power from the conversion power through an on-off operation of the second switch and the third switch,

wherein the controller is further configured to generate a converter control signal to be transmitted to the first switch and an inverter control signal to be transmitted to the second switch and the third switch, and

wherein either one or both of the converter control signal and the inverter control signal is changed according to a change in the operation mode.

13. A method of controlling a wireless power transmitting device, comprising:

detecting either one or both of a voltage or a current of a transmission coil in response to a wireless power transmitting device transmitting a wireless power to a receiving device through the transmission coil;

generating information of a distance between the wireless power transmitting device and the receiving device based on either one or both of the voltage or the current of the transmission coil;

generating information of a reference efficiency corresponding to the information of the distance;

comparing the reference efficiency to a power transmission efficiency of the wireless power transmitting device; and

reducing a magnitude of the wireless power in response to the power transmission efficiency being lower than the reference efficiency.

14. The method of controlling a wireless power transmitting device of claim 13, further comprising:

generating information of a magnitude of a received power by receiving, from the receiving device, a packet signal comprising the information of the magnitude of the received power of the receiving device, and demodulating the packet signal.

15. The method of controlling a wireless power transmitting device of claim 14, further comprising:

calculating a magnitude of a supplied power from a voltage and a current of a power source of the wireless power transmitting device,

wherein the comparing comprises calculating the power transmission efficiency based on the magnitude of the supplied power and the magnitude of the received power, and

wherein the detecting comprises detecting the voltage and the current of the power source.

16. A non-transitory computer-readable medium storing instructions that, when executed by a processor, cause the processor to perform the method of claim 13.

17. A wireless power transmitting device, comprising:

a wireless power generator configured to generate a wireless power based on a supplied power of a power source;

a wireless power transmitter configured to;

transmit the wireless power to a receiving device, and

receive information of a magnitude of a received power of the receiving device;

a power calculator configured to calculate a magnitude of the supplied power based on either one or both of a voltage and a current of the power source;

a distance calculator configured to calculate a distance from the wireless power transmitting device to the receiving device based on either one or both of a voltage and a current of the wireless power transmitter;

a comparator configured to;

determine a reference efficiency based on the distance,

calculate a power transmission efficiency based on the magnitude of the supplied power and the magnitude of the received power, and

compare the reference efficiency to the power transmission efficiency; and

a controller configured to control the wireless power generator to reduce the magnitude of the generated wireless power in response to the power transmission efficiency being lower than the reference efficiency.