KR20140120404A

KR20140120404A - Wireless power transmission apparatus, wireless power transmission system, and wireless power transmission method

Info

Publication number: KR20140120404A
Application number: KR20130035559A
Authority: KR
Inventors: 한민석; 박래혁; 김영선; 박운규; 류성한
Original assignee: 엘에스전선 주식회사
Priority date: 2013-04-02
Filing date: 2013-04-02
Publication date: 2014-10-14

Abstract

The present invention relates to a wireless power transmission apparatus for wirelessly transmitting power to a wireless power receiving apparatus through a magnetic field, the wireless power transmission apparatus comprising: a transmitting unit for generating the magnetic field; An impedance matching unit capable of adjusting an impedance so that the transmission unit has a resonant frequency; Detecting an input signal value at an input terminal of the power transmitting unit which changes in accordance with a change in the distance or position between the wireless power transmission apparatus and the wireless power receiving apparatus and comparing the input signal value with a predetermined signal value, A detector for outputting a value; And a controller for controlling the impedance of the impedance matching unit such that the maximum power is transferred to the wireless power receiving apparatus according to a change in distance or position between the wireless power transmitting apparatus and the wireless power receiving apparatus. A wireless power transmission system, and a wireless power transmission method.

Description

[0001] The present invention relates to a wireless power transmission apparatus, a wireless power transmission system, and a wireless power transmission method,

An embodiment of the present invention relates to a wireless power transmission apparatus, a wireless power transmission system, and a wireless power transmission method using the same.

Wireless power transmission refers to the technology that supplies power to home electric appliances or electric vehicles wirelessly instead of the conventional wired power line. The advantage of wireless power charging is that it can be charged wirelessly Therefore, related research is actively proceeding.

Wireless power transmission technologies include magnetic induction, magnetic resonance, and microwave. The magnetic induction method is a technique using magnetic induction coupling between adjacent coils. The distance between the two coils before sending is within a few cm, and the transmission efficiency is largely influenced by the arrangement condition of the two coils. The self-resonance method is a technique in which non-radiation magnetic field energy is transmitted between two resonators that are separated from each other by a resonant coupling. The distance between the coils before and after the transmission is 1 to 2 m, It is advantageous in that the alignment of the two coils is relatively flexible and the wireless chargeable range can be expanded by using the relaying method. The microwave method is a technology for transmitting electric power by radiating a very high frequency electromagnetic wave such as a microwave through an antenna. However, it is necessary to consider a safety problem by electromagnetic waves although long distance wireless power transmission is possible.

The wireless power transmission system comprises a wireless power transmission device for wirelessly transmitting power and a wireless power reception device for wirelessly receiving the power. In the wireless power transmission, the load impedance changes according to the distance or the relative position between the wireless power transmission device and the wireless power reception device, so that the resonance frequency of the wireless power transmission system changes. Accordingly, the wireless power transmission efficiency to the wireless power reception device .

Korean Patent Publication No. 2011-0131954, "Wireless Power Transmission Device and Method Thereof"

SUMMARY OF THE INVENTION A primary object of the present invention is to provide a wireless power transmission device, a wireless power transmission system, and a wireless power transmission system capable of preventing a degradation of wireless power transmission efficiency due to a change in load impedance as a distance between a wireless power transmission device and a wireless power reception device changes, And a method of wireless power transmission.

A wireless power transmission apparatus according to an embodiment of the present invention is a wireless power transmission apparatus for wirelessly transmitting power to a wireless power reception apparatus via a magnetic field, the wireless power transmission apparatus comprising: a transmission unit for generating the magnetic field; An impedance matching unit capable of adjusting an impedance so that the transmission unit has a resonant frequency; Detecting an input signal value at an input terminal of the power transmitting unit which changes in accordance with a change in the distance or position between the wireless power transmission apparatus and the wireless power receiving apparatus and comparing the input signal value with a predetermined signal value, A detector for outputting a value; And a controller for controlling the impedance of the impedance matching unit such that the maximum power is transferred to the wireless power receiving apparatus according to a change in distance or position between the wireless power transmitting apparatus and the wireless power receiving apparatus. .

In the present invention, when the input signal value is a current, the detection unit may convert the detected current into a voltage, compare the converted voltage with a predetermined voltage, and output the output signal value.

In the present invention, the detecting unit may include: a voltage converting unit converting the detected current into a voltage; A differential amplifier for outputting an output voltage proportional to a difference between the converted voltage and the preset voltage; And a noise removing unit removing the noise from the output voltage and outputting the output signal value.

In the present invention, the predetermined signal value may be a signal value when the wireless power transmission apparatus and the wireless power reception apparatus are critical coupling.

In the present invention, the distance between the wireless power receiving apparatus and the wireless power transmitting apparatus corresponds one-to-one with the output signal value varying with the change, and the wireless power transmitting apparatus is impedance-matched with the transmitting unit, And a storage unit for storing a matching impedance value of the impedance matching unit.

In the present invention, the storage unit may store the output signal value and the matching impedance value in the form of a look-up table.

In the present invention, the controller may search the storage unit for the matching impedance value corresponding to the output signal value output from the detecting unit, and may control the impedance matching unit such that the impedance matching unit has the matching impedance value .

The phase of the output signal value may be compensated for by changing the phase of the output signal value by compensating for the phase change occurring while the input signal value passes through the detection unit and outputting as the output signal value, And a phase compensating unit for compensating the phase of the output signal of the phase comparator.

A wireless power transmission system according to an embodiment of the present invention includes: a wireless power transmission apparatus that transmits a power signal to a transmission unit to generate a magnetic field around the transmission unit; And at least one wireless power receiving device coupled to the magnetic field for wirelessly receiving the power signal, wherein the wireless power transmitting device comprises: The input signal value at the input terminal is compared with a predetermined signal value, and based on this, the transmission unit is impedance-matched to transmit the optimal power signal to the wireless power receiving apparatus after the wireless power transmission apparatus is in a resonant state.

In the present invention, the wireless power transmission apparatus may further include: a transmission unit for generating the magnetic field; An impedance matching unit capable of adjusting an impedance so that the transmission unit has a resonant frequency; Detecting an input signal value at an input terminal of the power transmitting unit which changes in accordance with a change in the distance or position between the wireless power transmission apparatus and the wireless power receiving apparatus and comparing the input signal value with a predetermined signal value, A detector for outputting a value; And a controller for controlling the impedance of the impedance matching unit such that the maximum power is transferred to the wireless power receiving apparatus according to a change in distance or position between the wireless power transmitting apparatus and the wireless power receiving apparatus. .

In the present invention, the detecting unit may include: a voltage converting unit converting the detected current into a voltage; A differential amplifier for outputting an output voltage proportional to a difference between the converted voltage and the preset voltage; And a noise eliminator for removing noise from the output voltage and outputting the output signal value; As shown in FIG.

In the present invention, the predetermined signal value may be a signal value when the wireless power transmission apparatus and the wireless power reception apparatus are in a critical combination.

A wireless power transmission method according to an embodiment of the present invention is a wireless power transmission method for transmitting a magnetic field generated in a wireless power transmission apparatus to a wireless power reception apparatus through a wireless power relay apparatus, The distance between the wireless power receiving apparatus is changed; Detecting an input signal value input to an input terminal of a transmitter of the wireless power transmission apparatus; Comparing the input signal value with a preset signal value and outputting an output signal value; Impedance matching the transmission unit based on the output signal value; And transmitting the optimum power signal to the wireless power receiving apparatus after the wireless power transmitting apparatus is in a resonant state by the impedance matching; .

In the present invention, the resonance frequency of the wireless power transmission apparatus may vary as the distance between the wireless power transmission apparatus and the wireless power reception apparatus changes.

In the present invention, the input signal value may vary as the distance between the wireless power transmission apparatus and the wireless power reception apparatus changes.

In the present invention, the input signal value may be a current input to the transmission unit.

In the present invention, the output signal value output step may include: converting the current, which is the input signal value, into a voltage; And outputting the output signal value by obtaining a difference between the converted voltage and the predetermined signal value; .

In the present invention, the step of outputting the output signal value may further comprise removing noise of the output signal value.

In the present invention, the impedance matching step may include: selecting a matching impedance value corresponding to the output signal value in a lookup table having an impedance value corresponding to the output signal value; And impedance matching the transmission unit according to the matching impedance value. .

The phase difference between the output signal value output step and the impedance matching step may be compensated for by changing the phase of the output signal value while the input signal value is output as the output signal value, To be equal to the phase of the phase-compensated signal.

According to an embodiment of the present invention, even when the distance between the wireless power transmission apparatus and the wireless power reception apparatus changes, optimal wireless power transmission can be achieved by controlling the impedance so that the wireless power transmission apparatus is in a resonant state.

1 is a block diagram schematically showing a wireless power transmission system according to an embodiment of the present invention.
2 is a perspective view schematically showing a wireless power transmission apparatus and a wireless power reception apparatus constituting a wireless power transmission system according to an embodiment of the present invention.
3 is a block diagram schematically showing a wireless power transmission apparatus according to an embodiment of the present invention.
Fig. 4 is a circuit diagram schematically showing an example of the detection unit of Fig. 3; Fig.
5 is a circuit diagram schematically showing an example of the phase compensator of FIG.
FIG. 6A is a graph of the voltage output from the detector, and FIG. 6B is a graph of voltage output from the phase compensator.
7 is a flow chart schematically illustrating a wireless power transmission method according to an embodiment of the present invention.

While the present invention has been described in connection with certain exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and similarities. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. In addition, numerals (e.g., first, second, etc.) used in the description of the present invention are merely an identifier for distinguishing one component from another.

Also, in this specification, when an element is referred to as being "connected" or "connected" with another element, the element may be directly connected or directly connected to the other element, It should be understood that, unless an opposite description is present, it may be connected or connected via another element in the middle.

In this specification, a charging device is a portable device equipped with a rechargeable battery and capable of being used as a portable device such as a mobile phone, a smart phone, a laptop computer, a digital broadcasting terminal, a PDA (Personal Digital Assistants), a Portable Multimedia Player ), Navigation, and the like.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram schematically showing a wireless power transmission system according to an embodiment of the present invention.

As shown in FIG. 1, a wireless power transmission apparatus can transmit power between a wireless power transmission apparatus 10 and a wireless power reception apparatus 20 by a magnetic induction method or a magnetic resonance method.

The wireless power transmission apparatus 10 converts an AC power input from an external input power supply 12 into an electromagnetic wave signal through an internal circuit such as a rectification unit (not shown) and a voltage amplification unit (not shown) 11 to the wireless power receiving apparatus 20. [

The wireless power receiving apparatus 20 receives the electromagnetic wave signal transmitted from the wireless power transmitting apparatus 10. [ For this purpose, the wireless power receiving apparatus 20 may include a power receiver 21.

In the case of the magnetic resonance method, it is preferable that the resonance frequencies of the power transmission part 11 and the power reception part 21 are the same or substantially the same. In this case, an energy transfer channel is formed between the power transmitting part 11 and the power receiver 21 by resonant coupling. The electromagnetic wave emitted from the power transmission unit 11 is transmitted to the power receiving unit 21 through the energy transfer channel and the electromagnetic wave inputted through the power receiving unit 21 is received by the impedance matching unit ), A rectifying part (not shown), and the like. The converted power may be transmitted to the load device 30 connected to the wireless power receiving device 20 to charge the load device 30 or provide drive power.

In the case of using the magnetic induction method, the resonance frequencies of the power transmitting portion 11 and the power receiving portion 21 need not be substantially the same frequency. However, by matching the resonance frequencies of the power transmitting portion 11 and the power receiving portion 21 substantially equally The power transmission efficiency between both ends can be improved.

Hereinafter, a wireless power transmission system according to an embodiment of the present invention will be described with reference to FIG. 2 based on the wireless power transmission method described above.

2 is a schematic diagram illustrating a wireless power transmission apparatus and a wireless power reception apparatus constituting a wireless power transmission system according to an embodiment of the present invention.

2, a wireless power transmission system according to an embodiment of the present invention includes a wireless power transmission apparatus 10 and a wireless power reception apparatus 20 that is charged with power through the wireless power transmission apparatus 10 .

The wireless power transmission apparatus 10 can capture an alternating magnetic field in the air and convert it into electric power without connection with a separate external power source. The converted power can be transmitted to an external wireless power receiving apparatus 20 through a transmitting unit (transmission antenna) mounted inside the apparatus and can be used for charging a battery mounted inside the wireless power transmitting apparatus 10 have.

In addition, the wireless power transmission apparatus 10 may include a display unit (not shown) for displaying the magnitude of the alternating magnetic field sensed at the current position on the outside. Or a speaker (not shown) for externally displaying the magnitude of the sensed alternating magnetic field.

The wireless power transmission apparatus 10 transmits power to the wireless power receiving apparatus 20 through an RF signal through a transmission antenna, and the power transmission system may be a magnetic resonance system or a magnetic induction system.

In the case of the magnetic resonance method, when the wireless power transmission apparatus 10 and the wireless power reception apparatus 20 are spaced apart by a predetermined distance h, the maximum power transmission can be performed with the same resonance frequency. In this way, it is called critical coupling that the wireless power transmission apparatus 10 and the wireless power reception apparatus 20 have the same resonance frequency and maximum power transmission is performed.

However, when the wireless power transmission apparatus 10 and the wireless power reception apparatus 20 are within a certain distance h, they are located in the over-coupling region. In this case, a mode dispersion occurs and the wireless power transmission apparatus 10 And the wireless power receiving apparatus 20 have resonance frequencies different from each other at the time of critical coupling. For example, if the resonance frequency of the wireless power transmission apparatus 10 and the wireless power reception apparatus 20 is 250 KHz in the critical coupling, the wireless power transmission apparatus 10 has a resonance frequency at 240 KHz in the over- The power receiving apparatus 20 may have a resonant frequency at 260 KHz. Such a phenomenon occurs when the coupling coefficient k is inversely proportional to the distance and when the distance between the wireless power transmission apparatus 10 and the wireless power reception apparatus 20 is within a predetermined distance h at which critical coupling occurs, It affects each other.

Also, in the overcoupling region, the wireless power transmission apparatus 10 and the wireless power reception apparatus 20 are influenced by each other, and the influence of the input signal (current or voltage) of the transmission unit of the wireless power transmission apparatus 10 . &Lt; / RTI > The wireless power transmission apparatus 10 according to an exemplary embodiment of the present invention detects an input signal of a transmission unit that varies as the distance between the wireless power transmission apparatus 10 and the wireless power reception apparatus 20 changes, The resonance frequency of the wireless power transmission apparatus 10 can be adjusted so that the optimum power transmission is performed. This will be described later.

3 is a block diagram schematically illustrating a wireless power transmission apparatus according to an embodiment of the present invention.

3, a wireless power transmission apparatus 10 according to an exemplary embodiment of the present invention includes a rectifying unit 110, a voltage amplifying unit 120, an impedance matching unit 130, a detecting unit 140, 150, a control unit 160, a storage unit 170, and a power transmitting unit 180.

An external power supply is provided to the wireless power transmission device (10). The external power source is inputted to the rectifying unit 110 and converted into a direct current power source, and the converted direct current power source can be converted into an arbitrary voltage by the voltage amplifying unit 120.

The impedance matching unit 130 can change the resonant frequency of the power transmitting unit 180. [ Specifically, the impedance matching unit 130 is located at the front end of the power transmitting unit 180, and can match the impedance of the power transmitting unit 180 and the impedance of the front end of the impedance matching unit 130. For this purpose, the impedance matching unit 130 may include a variable inductor or a variable capacitor, or a parallel array structure in which a plurality of circuits in which a capacitor and a FET (field effect transistor) switch are directly connected to each other in parallel. At this time, the variable capacitor or the parallel array may be connected in series or parallel to the power transmitting unit 180 to change the capacitance value of the impedance matching unit 130, thereby changing the resonant frequency of the power transmitting unit 180. When the distance or position between the wireless power transmission apparatus 10 and the wireless power reception apparatus 20 changes and the resonance frequency at which the maximum power transmission occurs changes the impedance of the impedance matching unit 130, So that the optimum power transmission can be performed. This will be described later.

The power transmitting unit 180 can transmit power wirelessly. As an example, the power transmitting unit 180 can transmit power to the wireless power receiving apparatus 20 in accordance with a control signal of a controller 160, which will be described later. At this time, the transmitted power may be transmitted in the form of an RF (Radio Frequency) energy signal. It is preferable that the power transmitting unit 180 and the power receiver have the same or approximate resonance frequency. If the power transmission unit 180 and the power receiver have the same resonance frequency, maximum power transmission may occur.

The configuration of the transmitting unit 180 may vary according to the wireless power transmission scheme. For example, when the wireless power transmission system is implemented by a magnetic induction method, the power transmission unit 180 may be configured as a single loop antenna. On the other hand, when the wireless power transmission system is implemented by a magnetic resonance method, the power transmission unit 180 may be configured as a pair of transmission coil and transmission-only resonance coil. In addition, the transmitting unit 180 may be implemented in a loop form. For example, the transmitter 180 may be in the form of a spiral loop or a helical loop.

The detection unit 140 detects an input signal value at the input terminal D of the power transmission unit 180 which changes in accordance with a change in the distance or position between the wireless power transmission apparatus 10 and the wireless power reception apparatus 20, The output signal value Vp may be output by comparing the input signal value with a preset signal value.

The detection unit 140 may measure a current or a voltage at an input terminal D of the power transmission unit 180. The current or voltage measured at the input D may be the input signal value. If the input signal value is a current, the detector 140 may convert the detected current into a voltage, and may compare the converted voltage with a predetermined voltage to output an output signal value Vp. The predetermined signal value may be a signal value when the wireless power transmission apparatus 10 and the wireless power reception apparatus 20 are critical coupling. That is, the predetermined signal value is transmitted from the wireless power transmitting apparatus 10 to the wireless power receiving apparatus 20 in the resonant state in which the wireless power transmitting apparatus 10 and the wireless power receiving apparatus 20 have the same resonance frequency Current " or " voltage value "

2, when the wireless power transmission apparatus 10 and the wireless power reception apparatus 20 maintain a certain distance h, they are in a resonance state with each other. At this time, at the input terminal D of the transmission unit 180, May be a predetermined signal value. However, when the distance between the wireless power transmission apparatus 10 and the wireless power reception apparatus 20 becomes smaller than the distance h that is the critical coupling state, that is, in the over coupling region, the mode dispersion occurs and the wireless power transmission apparatus 10 And the wireless power receiving apparatus 20 have different resonance frequencies. In addition, the signal value at the input terminal D of the power transmitting unit 180 also has a different value from the predetermined signal value. The detection unit 140 can measure the signal value at the input terminal D of the power transmission unit 180 which changes in accordance with the change of the distance between the wireless power transmission apparatus 10 and the wireless power reception apparatus 20 , It is possible to output an output signal value by comparing with a preset signal value.

Fig. 4 is a circuit diagram schematically showing an example of the detection unit of Fig. 3; Fig.

4, the detecting unit 140 may include a voltage converting unit 142, a differential amplifier 141, and a noise removing unit 143.

The voltage converting unit 142 can convert the current measured at the input terminal D of the power transmitting unit 180 into a voltage.

The differential amplifier 141 may compare the voltage converted by the voltage converting unit 142 with the preset voltage and output an output signal value. The differential amplifier 141 may multiply the difference between the converted voltage and the preset voltage by a voltage gain to output an output signal value.

The noise eliminator 143 can remove noise from the output signal value output from the differential amplifier 141. [

The phase compensation unit 150 may be disposed between the control unit 160 and the detection unit 140. When the phase compensation unit 150 is positioned at the output of the detection unit 140, As shown in FIG.

The phase compensating unit 150 can compensate for a phase change occurring while the input signal value detected at the input terminal D of the power transmitting unit 180 is output as the output signal value Vp through the detecting unit 140 .

5 is a circuit diagram schematically showing an example of the phase compensator of FIG. 5, an output signal value Vp that has passed through the detector 140 is input to the comparator 151 to compensate for the phase of the output signal Vp whose phase is changed to obtain a phase equal to the phase of the input signal value Vp The output signal value Vc can be output.

6 is a graph showing the voltage Vp output from the detector 140 and the voltage Vc output from the phase compensator 150. FIG. More specifically, FIG. 6A is a graph of voltage output from the detector, and FIG. 6B is a graph of voltage output from the phase compensator.

Referring to FIG. 6A, it can be seen that the voltage Vp output from the detector 140 is phase-shifted by? T. This is due to the time delay that occurs when the input signal value detected at the input terminal D of the power transmitting unit 180 passes through the differential amplifier 141 and the noise removing unit 143 of the detecting unit 140.

The phase compensator 150 may compensate the phase of the output signal value Vp in which the phase shift has occurred. The phase compensation unit 150 can compensate the phase of the output signal value Vp equal to the phase of the input signal value detected at the input terminal D of the power transmitting unit 180. [

The controller 160 controls the impedance matching unit 130 to transmit optimum power to the wireless power receiving apparatus 20 according to a change in distance or position between the wireless power transmission apparatus 10 and the wireless power reception apparatus 20 Can be controlled. That is, when the distance or position between the wireless power transmission apparatus 10 and the wireless power reception apparatus 20 changes, the impedance of the wireless power reception apparatus 20 at the lower end is changed, The resonance frequency is changed, and impedance mismatching may occur in the impedance matching unit 130 and the power transmitting unit 180. The controller 160 controls the impedance matching unit 130 and the power transmitting unit 180 so that the impedance matching unit 130 and the power transmitting unit 180 are impedance matched even when the distance or position between the wireless power transmitting apparatus 10 and the wireless power receiving apparatus 20 changes. (130).

The matching impedance value that varies according to the change of the distance or position between the wireless power transmission apparatus 10 and the wireless power reception apparatus 20 may be stored in the storage unit 170 and the control unit 160 may control the phase compensation unit The storage unit 170 searches for a matching impedance value corresponding to the output signal value Vc output from the storage unit 150 and controls the impedance matching unit 130 to have the matching matching impedance value.

The storage unit 170 corresponds one-to-one with the output signal value Vc varying according to the change of the distance or position between the wireless power receiving apparatus 20 and the wireless power transmitting apparatus 10, The matching impedance value of the impedance matching unit 130 matching the wireless power transmission apparatus 10 in the resonance state can be stored. As an example, the storage unit 170 may store the output signal value Vc and the matching impedance value in the form of a look-up table.

7 is a flow chart schematically illustrating a wireless power transmission method according to an embodiment of the present invention.

Referring to FIG. 7, power transmission from the wireless power transmission apparatus 10 to the wireless power reception apparatus 20 may occur first (S101). When the wireless power transmission apparatus 10 and the wireless power reception apparatus 20 are in a critical combination, the distance between the wireless power transmission apparatus 10 and the wireless power reception apparatus 20 is, for example, If possible, maximum power transfer can occur.

Thereafter, there may be a change in the distance between the wireless power transmission apparatus 10 and the wireless power reception apparatus 20 (S102). Referring to FIG. 2, the distance between the wireless power receiving apparatus 20 and the wireless power transmitting apparatus 10 may be within h or h.

Thus, it is possible to detect the input signal value when the distance between the wireless power transmission apparatus 10 and the wireless power reception apparatus 20 changes. That is, the detection unit 140 can detect the input signal value at the input terminal D of the power transmission unit 180. [ Since the input signal value is a measured value at the input terminal D of the power transmitting unit 180 when the distance between the wireless power transmitting apparatus 10 and the wireless power receiving apparatus 20 is within h, And the input signal value at the input terminal D of the power transmitting unit 180 when the distance between the wireless power receiving apparatus 20 and the wireless power receiving apparatus 20 is h.

Next, the detection unit 140 may compare the input signal value with a preset signal value and output an output signal value (S104). When the input signal value is a current, the signal is converted into a voltage by the voltage converting unit 142, and compared with a predetermined signal value by the differential amplifier 141, and an output signal value may be output. The output signal value can be removed by the noise eliminator 143.

Next, the output signal value is phase-compensated by the phase compensator 150, and the output signal value whose phase is compensated can be input to the controller 160. The control unit 160 may search the storage unit 170 for the matching impedance value corresponding to the output signal value and may control the impedance matching unit 130 to have the matching impedance value at step S105.

Since the impedance matching unit 130 and the power transmitting unit 180 are impedance-matched by the matching impedance value, the wireless power transmission apparatus 10 can determine that the distance between the wireless power transmission apparatus 10 and the wireless power reception apparatus 20 is Even when the resonance frequency is changed, it is possible to transmit the optimum power to the wireless power receiving apparatus 20 because of the resonance state.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention.

Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments.

The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

110: rectification part 120: voltage amplification part
130: Impedance matching unit 140:
150: phase compensator 160:
170:

Claims

A wireless power transmission apparatus for wirelessly transmitting power to a wireless power receiving apparatus through a magnetic field,
A transmitting unit for generating the magnetic field;
An impedance matching unit capable of adjusting an impedance so that the transmission unit has a resonant frequency;
Detecting an input signal value at an input terminal of the power transmitting unit which changes in accordance with a change in the distance or position between the wireless power transmission apparatus and the wireless power receiving apparatus and comparing the input signal value with a predetermined signal value, A detector for outputting a value; And
A controller for controlling the impedance of the impedance matching unit such that the maximum power is transmitted to the wireless power receiving apparatus according to a change in distance or position between the wireless power transmitting apparatus and the wireless power receiving apparatus; And an antenna for transmitting the radio signal.

The method according to claim 1,
Wherein the detector converts the detected current into a voltage when the input signal value is a current, and outputs the output signal value by comparing the converted voltage with a predetermined voltage.

3. The method of claim 2,
Wherein:
A voltage converter for converting the detected current into a voltage;
A differential amplifier for outputting an output voltage proportional to a difference between the converted voltage and the preset voltage; And
A noise eliminator for removing noise from the output voltage and outputting the output signal value; Further comprising: a power control unit for controlling the power of the wireless power transmission apparatus.

The method according to claim 1,
Wherein the predetermined signal value is a signal value when the wireless power transmission apparatus and the wireless power reception apparatus are critical coupling.

The method according to claim 1,
Wherein the distance between the wireless power receiving apparatus and the wireless power transmitting apparatus corresponds one-to-one with an output signal value varying in accordance with the change, and the matching of the impedance matching unit in which the wireless power transmitting apparatus is impedance- And a storage unit for storing an impedance value.

6. The method of claim 5,
Wherein the storage unit stores the output signal value and the matching impedance value in the form of a look-up table.

6. The method of claim 5,
Wherein the control unit searches the storage unit for the matching impedance value corresponding to the output signal value output from the detecting unit and controls the impedance matching unit so that the impedance matching unit has the matching impedance value. Device.

The method according to claim 1,
And a control unit that is disposed between the control unit and the detection unit and compensates for a phase change occurring while the input signal value passes through the detection unit and is output as the output signal value to adjust the phase of the output signal value to be equal to the phase of the input signal value And a phase compensator configured to compensate the phase of the received signal.

A wireless power transmission device for transmitting a power signal to a power transmission part to generate a magnetic field around the power transmission part; And
And one or more wireless power receiving devices coupled to the magnetic field to receive the power signal wirelessly,
The wireless power transmission apparatus compares an input signal value at an input terminal of the power transmission unit, which changes as the distance from the wireless power reception apparatus changes, with a predetermined signal value, and impedance-matches the transmission unit based on the input signal value, Wherein the power transmitting apparatus is in a resonant state and transmits the optimum power signal to the wireless power receiving apparatus.

10. The method of claim 9,
The wireless power transmission apparatus comprising:
A transmitting unit for generating the magnetic field;
An impedance matching unit capable of adjusting an impedance so that the transmission unit has a resonant frequency;
Detecting an input signal value at an input terminal of the power transmitting unit which changes in accordance with a change in the distance or position between the wireless power transmission apparatus and the wireless power receiving apparatus and comparing the input signal value with a predetermined signal value, A detector for outputting a value; And
A controller for controlling the impedance of the impedance matching unit such that the maximum power is transmitted to the wireless power receiving apparatus according to a change in distance or position between the wireless power transmitting apparatus and the wireless power receiving apparatus; And a power control unit for controlling the power of the wireless power transmission system.

11. The method of claim 10,
Wherein the detector converts the detected current into a voltage when the input signal value is a current and outputs the output signal value by comparing the converted voltage with a predetermined voltage.

12. The method of claim 11,
Wherein:
A voltage converter for converting the detected current into a voltage;
A differential amplifier for outputting an output voltage proportional to a difference between the converted voltage and the preset voltage; And
A noise eliminator for removing noise from the output voltage and outputting the output signal value; Further comprising: a power control unit for controlling the power of the wireless power transmission system.

10. The method of claim 9,
Wherein the predetermined signal value is a signal value when the wireless power transmission apparatus and the wireless power reception apparatus are in a critical combination.

10. The method of claim 9,
Wherein the distance between the wireless power receiving apparatus and the wireless power transmitting apparatus corresponds one-to-one with an output signal value varying in accordance with the change, and the matching of the impedance matching unit in which the wireless power transmitting apparatus is impedance- And a storage unit for storing an impedance value.

15. The method of claim 14,
Wherein the storage unit stores the output signal value and the matching impedance value in the form of a look-up table.

15. The method of claim 14,
Wherein the control unit searches the storage unit for the matching impedance value corresponding to the output signal value output from the detecting unit and controls the impedance matching unit such that the impedance matching unit has the matching impedance value. system.

In the ninth aspect,
And a control unit that is disposed between the control unit and the detection unit and compensates for a phase change occurring while the input signal value passes through the detection unit and is output as the output signal value to adjust the phase of the output signal value to be equal to the phase of the input signal value And a phase compensating unit for compensating for a phase of the received signal.

A wireless power transmission method for transmitting a magnetic field generated by a wireless power transmission apparatus to a wireless power reception apparatus through a wireless power relay apparatus,
Varying a distance between the wireless power transmission device and the wireless power reception device;
Detecting an input signal value input to an input terminal of a transmitter of the wireless power transmission apparatus;
Comparing the input signal value with a preset signal value and outputting an output signal value;
Impedance matching the transmission unit based on the output signal value; And
Transmitting the optimum power signal to the wireless power receiving apparatus after the wireless power transmitting apparatus is in a resonant state by the impedance matching; And transmitting the wireless power to the base station.

19. The method of claim 18,
Wherein the resonance frequency of the wireless power transmission apparatus changes as the distance between the wireless power transmission apparatus and the wireless power reception apparatus changes.

19. The method of claim 18,
Wherein the input signal value changes as the distance between the wireless power transmission apparatus and the wireless power reception apparatus changes.

19. The method of claim 18,
Wherein the input signal value is a current input to the transmission unit.

22. The method of claim 21,
The output signal value output step includes:
Converting the current, which is the input signal value, into a voltage; And
Calculating a difference between the converted voltage and the predetermined signal value and outputting the output signal value; And transmitting the wireless power to the base station.

23. The method of claim 22,
Wherein the step of outputting the output signal value further comprises the step of removing noise of the output signal value.

19. The method of claim 18,
Wherein the predetermined signal value is a signal value when the wireless power transmission apparatus and the wireless power reception apparatus are in a critical combination.

19. The method of claim 18,
Wherein the impedance matching step comprises:
Selecting a matching impedance value corresponding to the output signal value in a look-up table having an impedance value corresponding to the output signal value; And
Impedance matching the transmission unit according to the matching impedance value; And transmitting the wireless power to the base station.

19. The method of claim 18,
Between the output signal value output step and the impedance matching step,
Further comprising a phase compensating step of compensating a phase change occurring while the input signal value is output as the output signal value to make the phase of the output signal equal to the phase of the input signal value. Transmission method.