WIRELESS POWER TRANSMISSION/RECEPTION APPARATUS AND METHOD

• US 20120146425A1
• Filed: 02/28/2011
• Published: 06/14/2012
• Est. Priority Date: 12/14/2010
• Status: Active Grant

• Current Assignee: Wit Co., Ltd.
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: Lee, Kwang Du, Kim, Jeong Hoon, Park, Joun Sup, Kim, Eung Ju, Hwang, Sang Hoon, Yoon, Young Seok, Park, Chul Gyun, Yoon, Jung Ho
• Granted Patent: US 8,803,365 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/20 using microwaves or radio frequency waves
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge
• CPC Class Codes: H04B 5/24 Inductive coupling
• CPC Class Codes: H04B 5/266 One coil at each side, e.g. with primary and secondary coils
• CPC Class Codes: H04B 5/70 specially adapted for specific purposes
• CPC Class Codes: H04B 5/77 for interrogation
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

Disclosed herein is a wireless power transmission/reception apparatus. The wireless power transmission/reception apparatus includes a wireless power transmission unit configured to generate a wireless power signal to be transmitted, transmit the wireless power signal using magnetic resonance, receive a reflected wireless power signal from a wireless power reception unit, determine whether a load device is present, and transmit a wireless power signal if it is determined that the load device is present in such a way that impedance and output power depending on variation in a distance to the load device are automatically tracked, and wireless power is supplied to the load device in an optimized state. A wireless to power reception unit is connected to the load device, and configured to receive the wireless power signal, provide the wireless power signal to the load device, and reflect a reflected wireless power signal towards the wireless power transmission unit.

Claims

1. A wireless power transmission/reception apparatus, comprising:

a wireless power transmission unit configured to receive externally input power, generate a wireless power signal to be transmitted in a wireless manner, transmit the generated wireless power signal using magnetic resonance, receive a reflected wireless power signal, determine whether a load device is present, and transmit a wireless power signal if it is determined that the load device is present in such a way that variations in impedance and output power depending on a variation in a distance to the load device are automatically tracked, and a wireless power signal, which has been matched to optimal impedance and which has been amplified to maximum output power, is transmitted in a wireless manner to allow power to be supplied to the load device; and

a wireless power reception unit connected to the load device, and configured to receive the wireless power signal from the wireless power transmission unit using magnetic resonance, to provide the wireless power signal to the load device connected to the wireless power reception unit, and to reflect a reflected wireless power signal, which was not consumed, towards the wireless power transmission unit.

2. The wireless power transmission/reception apparatus as set forth in claim 1, wherein the wireless power transmission unit comprises:

a frequency oscillator for receiving the externally input power and generating a wireless power signal desired to be transmitted;

a power amplifier for amplifying the wireless power signal generated by the frequency oscillator and outputting an amplified wireless power signal;

a first resonant antenna for transmitting the wireless power signal using magnetic resonance, and receiving the reflected wireless power signal that is reflected from the wireless power reception unit using magnetic resonance;

an impedance matching unit disposed between the power amplifier and the first resonant antenna and configured to vary impedance to optimal impedance so as to provide impedance matching between the power amplifier and the first resonant antenna;

a directional power coupler disposed between the power amplifier and the impedance matching unit or between the impedance matching unit and the first resonant antenna, and configured to have directionality such that the wireless power signal, which is input from the power amplifier or the impedance matching unit through a first port, is output to the first resonant antenna through a second port, and such that the reflected wireless power signal, which is input from the first resonant antenna through the second port, is output through a third port;

an output power detector for detecting output power from the wireless power signal which is output from the second port of the directional power coupler, and outputting detected output power;

a reflected power detector for detecting reflected power from the reflected wireless power signal which is output from the third port of the directional power coupler, and outputting detected reflected power;

a variable voltage regulator for varying an input voltage and transferring a boosted output voltage to the power amplifier so that a wireless power signal to be amplified by the power amplifier has maximum output power depending on an output power-to-reflected power ratio; and

a transmission controller for detecting whether a load device is present depending on the output power-to-reflected power ratio calculated using the output power and the reflected power which have been input, controlling the impedance matching unit so that if the load device is present, impedance attributable to the variation in the distance to the load device automatically varies depending on the output power-to-reflected power ratio, thereby realizing matching to optimal impedance, and controlling the variable voltage regulator so that if the load device is present, the output power attributable to the variation in the distance to the load device automatically varies depending on the output power-to-reflected power ratio, thereby allowing maximum output power to be tracked, the transmission controller performing control such that the wireless power signal which has been matched to the optimal impedance and has been amplified to the maximum output power is transmitted through the first resonant antenna.

3. The wireless power transmission/reception apparatus as set forth in claim 2, wherein the impedance matching unit comprises:

a transformer module including a primary coil and a secondary coil;

a plurality of first switches installed on the primary coil so that a turn ratio of the transformer module can be varied; and

a first switch controller connected to the plurality of first switches, and configured to control ON/OFF operations of the first switches under control of the transmission controller so that a turn ratio of the primary coil to the secondary coil varies so as to control impedance depending on the output power-to-reflected power ratio.

4. The wireless power transmission/reception apparatus as set forth in claim 2, wherein the variable voltage regulator comprises:

a Direct Current (DC)-DC converter for varying and boosting an input voltage, and outputting an output voltage which is divided into a reference voltage and a variable voltage so that the output voltage is adjustable depending on the output power-to-reflected power ratio;

a first load resistor for forming the reference voltage;

a resistance adjustment module connected between the first load resistor and a ground, and configured to include a plurality of parallel-connected second load resistors having different values and a plurality of switches connected to the respective second load resistors, the resistance adjustment module forming the variable voltage using a relevant second load resistor selected from among the plurality of second load resistors depending on the output power-to-reflected power ratio; and

a second switch controller for controlling ON/OFF operations of the second switches under control of the transmission controller so that a relevant second load resistor is selected from among the plurality of second load resistors depending on the output power-to-reflected power ratio,

wherein a maximum output voltage which varies with a ratio of resistances of the first load resistor to the selected second load resistor depending on the output power-to-reflected power ratio is provided to the power amplifier.

5. The wireless power transmission/reception apparatus as set forth in claim 2, wherein the transmission controller comprises:

a comparison module for comparing the output power-to-reflected power ratio, calculated using the output power and the reflected power which have been input, with a preset value, thus determining whether a load device is present;

an impedance tracking module for controlling the impedance matching unit so that if it is determined that the load device is present, impedance attributable to the variation in the distance to the load device automatically varies depending on the output power-to-reflected power ratio, thereby tracking optimal impedance; and

a power tracking module for controlling the variable voltage regulator so that if it is determined that the load device is present, output power attributable to the variation in the distance to the load device automatically varies depending on the output power-to-reflected power ratio, thereby tracking maximum output power.

6. The wireless power transmission/reception apparatus as set forth in claim 5, wherein the impedance tracking module comprises:

a first voltage division circuit provided with a plurality of series-connected resistors which have different values and are disposed between a reflected voltage detected from the reflected power and a ground, the first voltage division circuit dividing the reflected voltage into a plurality of reflected voltages using the plurality of resistors;

a first comparison circuit provided with a plurality of comparators, each individually receiving a corresponding one of the plurality of reflected voltages output from the first voltage division circuit and an output voltage detected from the output power, and determining whether the reflected voltage is at level lower than or higher than the output voltage via comparison of voltages, the plurality of reflected voltages being converted into levels by the comparators; and

a first output terminal selection circuit configured to allow any one high-level reflected voltage of the plurality of reflected voltages, converted into the levels by the first comparison circuit, to be output through one selected from among the plurality of output terminals,

wherein the impedance tracking module tracks optimal impedance in response to a first control signal which includes information about the output terminal selected by the first output terminal selection circuit, thus controlling the impedance matching unit.

7. The wireless power transmission/reception apparatus as set forth in claim 5, wherein the power tracking module comprises:

a second voltage division circuit provided with a plurality of series-connected resistors which have different values and are disposed between a reflected voltage detected from the reflected power and a ground, the second voltage division circuit dividing the reflected voltage into a plurality of reflected voltages using the plurality of resistors;

a second comparison circuit provided with a plurality of comparators, each individually receiving a corresponding one of the plurality of reflected voltages output from the second voltage division circuit and an output voltage detected from the output power, and determining whether the reflected voltage is at level lower than or higher than the output voltage via comparison of voltages, the plurality of reflected voltages being converted into levels by the comparators; and

a second output terminal selection circuit configured to allow any one high-level reflected voltage of the plurality of reflected voltages, converted into the levels by the second comparison circuit, to be output through one selected from among the plurality of output terminals,

wherein the power tracking module tracks maximum voltage in response to a second control signal which includes information about the output terminal selected by the second output terminal selection circuit, thus controlling the variable voltage regulator.

8. The wireless power transmission/reception apparatus as set forth in claim 2, wherein the wireless power transmission unit further comprises a power pass switch for providing a bypass path so that depending on whether the load device is present, the frequency oscillator is connected to the power amplifier, and the frequency oscillator is connected to the impedance matching unit or the directional power coupler.

9. The wireless power transmission/reception apparatus as set forth in claim 1, wherein the wireless power reception unit comprises:

a second resonant antenna for receiving the wireless power signal from the wireless power transmission unit using magnetic resonance, and reflecting the reflected wireless power signal towards the wireless power transmission unit;

a rectifier for rectifying the wireless power signal received by the second resonant antenna;

a power signal converter to which the load device is connected, the power signal converter converting the wireless power signal rectified by the rectifier into a power signal based on a power supply method and providing the power signal to the load device; and

a reception controller for performing control such that the second resonant antenna receives the wireless power signal using magnetic resonance and power is supplied to the load device, and performing control such that the reflected wireless power signal is reflected towards the wireless power transmission unit.

10. The wireless power transmission/reception apparatus as set forth in claim 9, wherein the wireless power reception unit further comprises a switch disposed between the second resonant antenna and the rectifier and configured to interrupt transmission of the wireless power received from the second resonant antenna,

wherein the reception controller interrupts the transmission of the power received from the second resonant antenna by controlling the switch when connection to the load device is released.

11. A wireless power transmission device, comprising:

a frequency oscillator for receiving externally input power and generating a wireless power signal desired to be transmitted;

a power amplifier for amplifying the wireless power signal generated by the frequency oscillator and outputting an amplified wireless power signal;

a first resonant antenna for transmitting the wireless power signal using magnetic resonance, and receiving a reflected wireless power signal that is reflected from a wireless power reception device using magnetic resonance;

an impedance matching unit disposed between the power amplifier and the first resonant antenna and configured to vary impedance to optimal impedance so as to provide impedance matching between the power amplifier and the first resonant antenna;

a directional power coupler disposed between the power amplifier and the impedance matching unit or between the impedance matching unit and the first resonant antenna, and configured to have directionality such that the wireless power signal, which is input from the power amplifier or the impedance matching unit through a first port, is output to the first resonant antenna through a second port, and such that the reflected wireless power signal, which is input from the first resonant antenna through the second port, is output through a third port;

an output power detector for detecting output power from the wireless power signal which is output from the second port of the directional power coupler, and outputting detected output power;

a reflected power detector for detecting reflected power from the reflected wireless power signal which is output from the third port of the directional power coupler, and outputting detected reflected power;

a variable voltage regulator for varying an input voltage and transferring a boosted output voltage to the power amplifier so that a wireless power signal to be amplified by the power amplifier has maximum output power depending on an output power-to-reflected power ratio; and

a transmission controller for detecting whether a load device is present depending on an output power-to-reflected power ratio calculated using the output power and the reflected power which have been input, controlling the impedance matching unit so that if the load device is present, impedance attributable to a variation in a distance to the load device automatically varies depending on the output power-to-reflected power ratio, thereby realizing matching to optimal impedance, and controlling the variable voltage regulator so that if the load device is present, the output power attributable to the variation in the distance to the load device automatically varies depending on the output power-to-reflected power ratio, thereby allowing maximum output power to be tracked, the transmission controller performing control such that the wireless power signal which has been matched to the optimal impedance and has been amplified to the maximum output power is transmitted through the first resonant antenna.

12. The wireless power transmission device as set forth in claim 11, wherein the impedance matching unit comprises:

a transformer module including a primary coil and a secondary coil;

a plurality of first switches installed on the primary coil so that a turn ratio of the transformer module can be varied; and

a first switch controller connected to the plurality of first switches, and configured to control ON/OFF operations of the first switches under control of the transmission controller so that a turn ratio of the primary coil to the secondary coil varies so as to control impedance depending on the output power-to-reflected power ratio.

13. The wireless power transmission device as set forth in claim 11, wherein variable voltage regulator comprises:

a Direct Current (DC)-DC converter for varying and boosting an input voltage, and outputting an output voltage which is divided into a reference voltage and a variable voltage so that the output voltage is adjustable depending on the output power-to-reflected power ratio;

a first load resistor for forming the reference voltage;

a resistance adjustment module connected between the first load resistor and a ground, and configured to include a plurality of parallel-connected second load resistors having different values and a plurality of switches connected to the respective second load resistors, the resistance adjustment module forming the variable voltage using a relevant second load resistor selected from among the plurality of second load resistors depending on the output power-to-reflected power ratio; and

a second switch controller for controlling ON/OFF operations of the second switches under control of the transmission controller so that a relevant second load resistor is selected from among the plurality of second load resistors depending on the output power-to-reflected power ratio,

wherein a maximum output voltage which varies with a ratio of resistances of the first load resistor to the selected second load resistor depending on the output power-to-reflected power ratio is provided to the power amplifier.

14. The wireless power transmission device as set forth in claim 11, wherein the transmission controller comprises:

a comparison module for comparing the output power-to-reflected power ratio, calculated using the output power and the reflected power which have been input, with a preset value, thus determining whether a load device is present;

an impedance tracking module for controlling the impedance matching unit so that if it is determined that the load device is present, impedance attributable to the variation in the distance to the load device automatically varies depending on the output power-to-reflected power ratio, thereby tracking optimal impedance; and

a power tracking module for controlling the variable voltage regulator so that if it is determined that the load device is present, output power attributable to the variation in the distance to the load device automatically varies depending on the output power-to-reflected power ratio, thereby tracking maximum output power.

15. The wireless power transmission device as set forth in claim 14, wherein the impedance tracking module comprises:

a first voltage division circuit provided with a plurality of series-connected resistors which have different values and are disposed between a reflected voltage detected from the reflected power and a ground, the first voltage division circuit dividing the reflected voltage into a plurality of reflected voltages using the plurality of resistors;

a first comparison circuit provided with a plurality of comparators, each individually receiving a corresponding one of the plurality of reflected voltages output from the first voltage division circuit and an output voltage detected from the output power, and determining whether the reflected voltage is at level lower than or higher than the output voltage via comparison of voltages, the plurality of reflected voltages being converted into levels by the comparators; and

a first output terminal selection circuit configured to allow any one high-level reflected voltage of the plurality of reflected voltages, converted into the levels by the first comparison circuit, to be output to through one selected from among the plurality of output terminals,

wherein the impedance tracking module tracks optimal impedance in response to a first control signal which includes information about the output terminal selected by the first output terminal selection circuit, thus controlling the impedance matching unit.

16. The wireless power transmission device as set forth in claim 15, wherein the first output terminal selection circuit comprises:

a plurality of AND gates, input terminals of which are respectively connected to the plurality of comparators, and output terminals of which are respectively connected to the plurality of output terminals; and

a plurality of inverters connected to respective first terminals of the input terminals of the AND gates.

17. The wireless power transmission device as set forth in claim 15, wherein the first output terminal selection circuit comprises:

a plurality of NOR gates, input terminals of which are respectively connected to the plurality of comparators, and output terminals of which are respectively connected to the plurality of output terminals; and

a plurality of inverters connected to respective first terminals of the input terminals of the NOR gates.

18. The wireless power transmission device as set forth in claim 14, wherein the power tracking module comprises:

a second voltage division circuit provided with a plurality of series-connected resistors which have different values and are disposed between a reflected voltage detected from the reflected power and a ground, the second voltage division circuit dividing the reflected voltage into a plurality of reflected voltages using the plurality of resistors;

a second comparison circuit provided with a plurality of comparators, each individually receiving a corresponding one of the plurality of reflected voltages output from the second voltage division circuit and an output voltage detected from the output power, and determining whether the reflected voltage is at level lower than or higher than the output voltage via comparison of voltages, the plurality of reflected voltages being converted into levels by the comparators; and

a second output terminal selection circuit configured to allow any one high-level reflected voltage of the plurality of reflected voltages, converted into the levels by the second comparison circuit, to be output through one selected from among the plurality of output terminals,

wherein the power tracking module tracks maximum voltage in response to a second control signal which includes information about the output terminal selected by the second output terminal selection circuit, thus controlling the variable voltage regulator.

19. The wireless power transmission device as set forth in claim 18, wherein the second output terminal selection circuit comprises:

a plurality of AND gates, input terminals of which are respectively connected to the plurality of comparators, and output terminals of which are respectively connected to the plurality of output terminals; and

a plurality of inverters connected to respective first terminals of the input terminals of the AND gates.

20. The wireless power transmission device as set forth in claim 18, wherein the second output terminal selection circuit comprises:

a plurality of NOR gates, input terminals of which are respectively connected to the plurality of comparators, and output terminals of which are respectively connected to the plurality of output terminals; and

a plurality of inverters connected to respective first terminals of the input terminals of the NOR gates.

21. The wireless power transmission device as set forth in claim 11, further comprising a power pass switch for providing a bypass path so that depending on whether the load device is present, the frequency oscillator is connected to the power amplifier, and the frequency oscillator is connected to the impedance matching unit or the directional power coupler.

22. The wireless power transmission device as set forth in claim 11, wherein the directional power coupler is either a circulator or an isolator.

23. A wireless power reception device, the wireless power reception device being connected to a load device, comprising:

a second resonant antenna for receiving a wireless power signal from a wireless power transmission device using magnetic resonance, and reflecting a reflected wireless power signal towards the wireless power transmission device;

a rectifier for rectifying the wireless power signal received by the second resonant antenna;

a power signal converter to which the load device is connected, the power signal converter converting the wireless power signal rectified by the rectifier into a power signal based on a power supply method and providing the power signal to the load device; and

a reception controller for performing control such that the second resonant antenna receives the wireless power signal using magnetic resonance and power is supplied to the load device, and performing control such that the reflected wireless power signal is reflected towards the wireless power transmission device.

24. The wireless power reception device as set forth in claim 23, further comprising a switch disposed between the second resonant antenna and the rectifier and configured to interrupt transmission of the wireless power received from the second resonant antenna,

wherein the reception controller interrupts the transmission of the power received from the second resonant antenna by controlling the switch when connection to the load device is released.

25. The wireless power reception device as set forth in claim 23, wherein the power signal converter comprises:

an Alternating Current (AC) converter for converting the rectified wireless power signal into an AC signal; and

an AC-DC converter for converting the rectified wireless power signal into a DC signal.

26. A wireless power transmission/reception method, comprising:

(A) a wireless power transmission unit transmitting a wireless power signal to a wireless power reception unit using magnetic resonance, detecting reflected power from a reflected wireless power signal, and determining whether a load device connected to the wireless power reception unit is present; and

(B) if it is determined that the load device connected to the wireless power reception unit is present, the wireless power transmission unit automatically tracking variations in impedance and output power attributable to a variation in a distance between the wireless power transmission unit and the load device, and then transmitting a wireless power signal which has been matched to optimal impedance and has been amplified to maximum output power.

27. The wireless power transmission/reception method as set forth in claim 26, wherein (A) comprises:

(A-1) the wireless power transmission unit transmitting the wireless power signal to the wireless power reception unit using magnetic resonance;

(A-2) the wireless power reception unit receiving the wireless power signal and reflecting the reflected wireless power signal; and

(A-3) the wireless power transmission unit receiving the reflected wireless power signal and detecting reflected power from the reflected wireless power signal, and thereafter determining whether a to load device connected to the wireless power reception unit is present depending on an output power-to-reflected power ratio which uses both the reflected power and output power detected from the wireless power signal.

28. The wireless power transmission/reception method as set forth in claim 26, wherein (B) comprises:

(B-1) if it is determined by the wireless power transmission unit that the load device connected to the wireless power transmission unit is present, the wireless power transmission unit automatically varying impedance attributable to a variation in a distance between the wireless power transmission unit and the load device depending on the output power-to-reflected power ratio, thus tracking optimal impedance;

(B-2) if it is determined by the wireless power transmission unit that the load device connected to the wireless power transmission unit is present, the wireless power transmission unit automatically varying output power attributable to the variation in the distance between the wireless power transmission unit and the load device depending on the output power-to-reflected power ratio, thus tracking maximum output power; and

(B-3) transmitting a wireless power signal which has been matched to the tracked optimal impedance and has been amplified to the tracked maximum output power.

29. A wireless power transmission method, comprising:

(A) a wireless power transmission unit transmitting a wireless power signal to a wireless power reception unit using magnetic resonance;

(B) the wireless power transmission unit receiving a reflected wireless power signal which has been reflected from the wireless power reception unit, detecting reflected power from the reflected wireless power signal, and determining whether a load device connected to the wireless power reception unit is present depending on an output power-to-reflected power ratio which uses both the reflected power and output power detected from the wireless power signal;

(C) if it is determined by the wireless power transmission unit that the load device connected to the wireless power reception unit is present, the wireless power transmission unit automatically tracking variations in impedance and output power attributable to the variation in the distance between the wireless power transmission unit and the load device; and

(D) transmitting a wireless power signal which has been matched to the tracked optimal impedance and has been amplified to the tracked maximum output power.

30. The wireless power transmission method as set forth in claim 29, wherein (B) comprises:

(B-1) the wireless power transmission unit receiving the reflected wireless power signal which has been reflected from the wireless power reception unit, detecting the reflected power from the reflected wireless power signal, and detecting output power from the wireless power signal; and

(B-2) comparing the output power-to-reflected power ratio which uses both the output power and the reflected power with a preset value, and then determining whether a load device connected to the wireless power reception unit is present.

31. The wireless power transmission method as set forth in claim 29, wherein (C) comprises:

(C-1) if it is determined by the wireless power transmission unit that the load device connected to the wireless power transmission unit is present, the wireless power transmission unit automatically varying impedance attributable to the variation in the distance between the wireless power transmission unit and the load device depending on the output power-to-reflected power ratio, thus tracking optimal impedance;

(C-2) if it is determined by the wireless power transmission unit that the load device connected to the wireless power transmission unit is present, the wireless power transmission unit automatically varying output power attributable to the variation in the distance between the wireless power transmission unit and the load device depending on the output power-to-reflected power ratio, thus tracking maximum output power; and

(C-3) transmitting a wireless power signal which has been matched to the tracked optimal to impedance and has been amplified to the tracked maximum output power.

32. A wireless power reception method, comprising:

(A) a wireless power reception unit receiving a wireless power signal which has been transmitted from a wireless power transmission unit, providing the wireless power signal to a load device connected to the wireless power reception unit, and thereafter reflecting a reflected wireless power signal; and

(B) if connection of the load device to the wireless power reception unit is released, stopping reception of the wireless power signal transmitted from the wireless power transmission unit.