KR20130087452A - A wireless power transmission apparatus and method thereof - Google Patents

Abstract

PURPOSE: A wireless power transmitting device and a method thereof are provided to improve energy transmission efficiency by transmitting energy through a specific relay resonator. CONSTITUTION: A relay resonant unit includes a plurality of relay resonators. A power source (10) delivers AC power to the relay resonant unit. The AC power has a mutual change resonant frequency. The mutual change resonant frequency is changed by a mutual inductance component. The mutual inductance component is included in a wireless power receiving device (80) and the relay resonant unit. [Reference numerals] (10) Power source

Description

Wireless power transmission apparatus and method thereof {A WIRELESS POWER TRANSMISSION APPARATUS AND METHOD THEREOF}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to wireless power transmission technology, and more particularly, to a wireless power transmission device and a method for efficiently transmitting energy using a magnetic resonance phenomenon.

Wireless power transmission technology (wireless power transmission or wireless energy transfer), which transfers electric energy to a desired device wirelessly, has already started to use electric motors or transformers using electromagnetic induction principles in the 1800s, and then radio waves A method of transmitting electrical energy by radiating electromagnetic waves such as waves or lasers has also been attempted. Our electric toothbrushes and some wireless shavers are actually charged with electromagnetic induction. To date, energy transmission methods using wireless methods include magnetic induction, magnetic resonance, and long-distance transmission technology using short wavelength radio frequencies.

In recent years, the application of short-range wireless power transmission technology, which is an issue, is to install a wireless power transmission device in a building and use a separate power supply when a user uses a wireless power receiver in a mobile device such as a mobile phone or a laptop. A typical case is charging continuously without a cable connection.

However, in the conventional wireless power transmission technology, there is a problem in that power is wasted and harmful to the human body since the power is always transmitted or relayed regardless of the existence and location of the wireless power receiver for receiving power.

As a related prior patent document there is Japanese Patent Laid-Open No. 2011-151989.

The present invention provides a wireless power transmission device and a method for transmitting energy using a magnetic resonance phenomenon.

The present invention also provides a wireless power transmitter and method for transmitting energy through a specific relay resonator corresponding to the position of the wireless power receiver.

A wireless power transmitter for wirelessly transmitting power to a wireless power receiver using resonance according to an embodiment of the present invention includes a mutual resonant unit modified by a relay resonator and mutual inductance components of the wireless power receiver and the relay resonator unit. And a power source for delivering AC power having a frequency to the relay resonator.

In addition, a wireless power repeater for wirelessly transmitting power to a wireless power receiver using resonance according to an embodiment of the present invention, comprising a plurality of relay resonators, the wireless power repeater of the plurality of relay resonators Characterized in that the AC power having a mutual change resonance frequency changed by the mutual inductance component of the relay resonator corresponding to the position of the wireless power receiver is characterized in that for transmitting to the wireless power receiver.

According to an embodiment of the present disclosure, the wireless power transmitter may improve energy transmission efficiency to the wireless power receiver by transmitting energy through a relay resonator corresponding to the position of the wireless power receiver.

In addition, the wireless power transmission apparatus can reduce energy waste and reduce generation of magnetic fields harmful to a human body by concentrating energy transmission through a specific relay resonator.

In addition, the wireless power transmitter transmits energy by using the mutual resonance frequency generated by the mutual inductance component between the specific relay resonator and the wireless power receiver, so that the wireless power transmitter can be implemented as a simple circuit having a lower cost than the active transmission method. have.

Meanwhile, various other effects will be directly or implicitly disclosed in the detailed description according to the embodiment of the present invention to be described later.

1 is a view for explaining a wireless power transmission system according to an embodiment of the present invention;
2 is an equivalent circuit diagram of a transmitting coil unit according to an exemplary embodiment of the present disclosure;
3 is an equivalent circuit diagram of a power source and a transmitter according to an embodiment of the present invention;
4 is an equivalent circuit diagram of a reception resonance coil unit, a reception coil unit, a smoothing circuit, and a load according to an embodiment of the present invention;
5 is a block diagram of a wireless power transmission system according to another embodiment of the present invention;
6 is an equivalent circuit diagram of a relay resonator and a wireless power receiver for calculating mutual resonance frequencies.

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. The following terms are defined in consideration of the functions of the present invention, and may be changed according to the intentions or customs of the user, the operator, and the like. Therefore, the definition should be based on the contents throughout this specification.

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

1 illustrates a wireless power transmission system according to an embodiment of the present invention.

Referring to FIG. 1, a wireless power transmission system includes a power source 10, a power transmitter 20, a power receiver 30, a rectifier circuit 40, and a load 50.

The power generated by the power source 10 is transmitted to the power transmitter 20, and is resonated with the power transmitter 20 by a self resonance phenomenon, that is, is transmitted to the power receiver 30 having the same resonance frequency value. Power delivered to the power receiver 30 is transferred to the load 50 via the rectifier circuit 40. In this case, the load 50 may be a rechargeable battery or any device requiring power.

More specifically, the power source 10 is an AC power source that provides AC power with a predetermined frequency.

The power transmitter 20 is composed of a transmitter coil unit 21 and a transmission resonance coil unit 22. The transmission coil unit 21 is connected to the power source 10, the alternating current flows. When an alternating current flows through the transmission coil part 21, an alternating current is also induced in the transmission resonant coil part 22 which is physically spaced by electromagnetic induction. Power transmitted to the transmission resonant coil unit 22 is transferred to the power receiver 30 forming a resonance circuit with the power transmitter 20 by magnetic resonance.

Power transmission by magnetic resonance is a phenomenon in which power is transmitted between two LC circuits with matching impedances, and thus power can be transmitted with greater efficiency up to a far distance than power transmission by electromagnetic induction.

The power receiver 30 includes a reception resonance coil unit 31 and a reception coil unit 32. The power transmitted by the transmission resonant coil unit 22 is received by the reception resonant coil unit 31 so that an AC current flows in the reception resonant coil unit 31. Power transmitted to the reception resonant coil unit 31 is transferred to the reception coil unit 32 by electromagnetic induction. Power delivered to the receiving coil unit 32 is rectified through the rectifier circuit 40 and delivered to the load 50.

2 is an equivalent circuit of the transmitting coil unit 21 according to an embodiment of the present invention. As shown in FIG. 2, the transmitting coil unit 21 may be composed of an inductor L1 and a capacitor C1, thereby forming a circuit having appropriate inductance and capacitance values.

The capacitor C1 may be a fixed capacitor or a variable capacitor. When the capacitor C1 is a variable capacitor, the power transmitter 20 may perform impedance matching by adjusting the variable capacitor. Meanwhile, an equivalent circuit of the transmission resonant coil unit 22, the reception resonant coil unit 31, and the reception coil unit 32 may also be the same as that shown in FIG. 2.

3 is an equivalent circuit of the power source 10 and the power transmitter 20 according to an embodiment of the present invention. As shown in FIG. 3, the transmission coil unit 21 and the transmission resonant coil unit 22 may be formed of inductors L1 and L2 and capacitors C1 and C2 having predetermined inductance values and capacitance values, respectively. .

In particular, the capacitor C2 of the transmission resonant coil unit 22 may be a variable capacitor, and the power transmitter 20 may adjust the variable capacitor to adjust a resonance frequency value for self resonance.

4 is an equivalent circuit of the reception resonance coil unit 31, the reception coil unit 32, the smoothing circuit 40, and the load 50 according to an embodiment of the present disclosure. As shown in FIG. 4, the reception resonant coil unit 31 and the reception coil unit 32 may be formed of inductors L3 and L4 and capacitors C3 and C4 having predetermined inductance values and capacitance values, respectively. .

The smoothing circuit 40 may be composed of a diode D1 and a smoothing capacitor C5, and converts AC power into DC power and outputs the same. The load 50 is indicated by a DC power supply of 1.3 V, but may be any rechargeable battery or device requiring DC power.

Meanwhile, in the following embodiment of the present invention, a wireless power transmitter and method for transmitting energy through a specific relay resonator corresponding to the position of the wireless power receiver will be described.

5 illustrates a configuration of a wireless power transmission system according to another embodiment of the present invention.

Referring to FIG. 5, the wireless power transmission system includes a wireless power transmitter 60, a relay resonator 70, and a wireless power receiver 80. Hereinafter, in the present embodiment, the wireless power transmitter 60 transmits energy to the wireless power receiver 80 through the relay resonator 70.

The wireless power transmission device 60 includes a power source 10, a transmission coil unit 21, and a transmission resonance coil unit 22. The wireless power transmitter 60 transmits energy directly to the wireless power receiver, or transmits energy to the wireless power receiver through a specific relay resonator.

The power source 10 generates AC power of a specific frequency for energy transfer by magnetic resonance. That is, the power source 10 generates AC power having a mutual resonant frequency caused by the mutual inductance component between the specific relay resonator and the wireless power receiver.

The transmission coil unit 21 is connected to the power source 10, the alternating current flows. When an alternating current flows through the transmission coil part 21, an alternating current is also induced in the transmission resonant coil part 22 which is physically spaced by electromagnetic induction. Power transmitted to the transmission resonant coil unit 22 is transferred to the reception device forming the resonance circuit with the transmission device by magnetic resonance.

The transmission resonant coil unit 22 includes a capacitor 22a, and the capacitor 22a may be a fixed capacitor or a variable capacitor.

When the capacitor 22a of the transmission resonant coil unit 22 is a variable capacitor, the wireless power transmitter 60 adjusts its own resonance frequency for self resonance through the capacitor 22a of the transmission resonant coil unit 22. Can be.

The relay resonator 70 relays energy transmitted from the transmission resonant coil unit 22 through magnetic resonance to the wireless receiver 80.

The relay resonator 65 in the relay resonator 70 may be larger than the reception resonant coil unit included in the wireless power receiver. This is because a coupling coefficient of more than a threshold value must exist between the resonant coil on the transmitting side and the resonant coil on the receiving side for efficient wireless power transmission. Therefore, the energy transmission method using the plurality of relay resonators 65 increases the transmission efficiency than the method of directly transferring energy from the wireless power transmitter to the wireless power receiver.

The relay resonator 70 includes a plurality of relay resonators 65 regularly arranged. In this case, the plurality of relay resonators 60 may be configured to have the same size and shape, respectively. In addition, the relay resonator 70 may be spaced apart from each other at a predetermined distance from the wireless power transmitter.

In addition, the relay resonator 70 illustrates that 12 relay resonators are arranged in a lattice form or a matrix form, but is not limited thereto. In addition, the relay resonator 70 is illustrated as being configured in the shape of a rectangular relay pad, but is not limited thereto.

Each of the plurality of relay resonators 65 may include the same capacitor 65a, and the capacitor 65a may be a fixed capacitor. In this case, the plurality of relay resonators 65 each have the same self resonant frequency f ₁ .

When the wireless power receiver 80 is positioned on the relay resonator 70, the wireless power transmitter 60 transmits energy through a specific relay resonator corresponding to the position of the wireless power receiver 80. .

The wireless power receiver 80 includes a reception resonance coil unit, a reception coil unit, a rectifier circuit, and a load. However, as shown in FIG. 5, for convenience of description, the wireless power receiver 80 may be briefly represented as including a reception resonance coil unit and a reception coil unit.

The power transmitted by the transmission resonant coil unit 22 is received by the reception resonant coil unit 31 so that an AC current flows in the reception resonant coil unit 31. Power transmitted to the reception resonant coil unit 31 is transferred to the reception coil unit 32 by electromagnetic induction. Power delivered to the receiving coil unit 32 is rectified through the rectifier circuit 40 and delivered to the load 50.

The receiving resonant coil part of each receiving device includes the same capacitor, and the capacitor may be a fixed capacitor. At this time, each receiving device has the same self resonant frequency f ₂ . In addition, the receiving device may be designed to have the same value as the self resonant frequency of the relay resonator 70.

When the wireless power receiver 80 is positioned on the relay resonator 70, the wireless power transmitter 60 transmits energy through a specific relay resonator corresponding to the position of the wireless power receiver 80. . In this case, the wireless power transmitter 60 generates power having mutual resonance frequencies, thereby transmitting energy through a specific relay resonator corresponding to the position of the wireless power receiver 80.

The wireless power transmitter transmits energy to a wireless power receiver through a specific relay resonator as follows.

When the receiving device is close to a specific relay resonator among the plurality of relay resonators, the inductor L1 component of the specific relay resonator and the inductor L2 component of the receiving apparatus are coupled to each other to generate mutual inductance components. In this case, the mutual inductance component is defined as in Equation 1 below.

[Equation 1]

, 여기서 k는 결합 계수(coupling coefficient), L₁은 송신 공진부의 자기 인덕턴스, L₂는 수신 장치의 자기 인덕턴스이다.

Where k is the coupling coefficient, L ₁ is the magnetic inductance of the transmission resonator, and L ₂ is the magnetic inductance of the receiver.

The mutual inductance component M generated between the specific relay resonator and the receiving device changes the self resonance frequency of the specific relay resonator or the receiving device, and the changed resonance frequency is referred to as the mutual resonance frequency f ₃ .

Depending on the distance and position between a particular relay resonator and a receiving device, the mutual inductance component generated between the two devices varies. In the present embodiment, the mutual resonance frequency f ₃ is preferably set to a resonance frequency value changed by mutual inductance components when the receiving devices are positioned directly above a specific relay resonator.

6 shows an equivalent circuit of a particular relay resonator and a receiving device for calculating the mutual resonance frequency.

Referring to FIG. 6, the self resonance frequency f ₁ of a specific relay resonator is defined as in Equation 2 below.

&Quot; (2) "

, 여기서 L1은 중계 공진기의 인덕턴스 값이고, C1은 중계 공진기의 캐패시턴스 값이다.

Where L1 is the inductance value of the repeater resonator and C1 is the capacitance value of the repeater resonator.

The self resonant frequency f ₂ of the receiving device is defined as in Equation 3 below.

&Quot; (3) "

, 여기서 L2는 수신 장치의 인덕턴스 값이고, C2는 수신 장치의 캐패시턴스 값이다.

Where L2 is the inductance value of the receiving device and C2 is the capacitance value of the receiving device.

In Fig. 6, input impedances Z ₁ and Z ₂ due to mutual inductance components between the relay resonator and the receiving device. Is defined as in Equations 4 and 5 below.

&Quot; (4) "

&Quot; (5) "

With such a mutual inductance, an inductance component of the intermediate resonator is changed from L ₁ as shown in equation (5) below as L _1. In other words, the inductance component of the relay resonator is represented by Equation Z ₁ .

&Quot; (6) "

By the mutual inductance component, the mutual resonance frequency f ₃ of the relay resonator may be calculated by Equation 7 below.

[Equation 7]

Meanwhile, in Equation 7, the mutual resonant frequency of the receiving device may be calculated by changing L ₁ to L ₂ , C ₁ to C ₂ , L ₂ to L ₁ , and C ₂ to C ₁ values. The value is equal to the mutual resonance frequency of the repeater resonator.

The wireless power transmitter 60 previously stores information about the mutual resonance frequency f ₃ . In addition, the wireless power transmitter 60 generates AC power having a mutual resonance frequency f ₃ through the power source 10 to transmit energy through a specific relay resonator corresponding to the position of the wireless power receiver. do. That is, the actual energy transfer is made of the mutual resonance frequency f ₃ , not the self resonance frequency.

For example, as shown in FIG. 5, the receiver 80 is When positioned over the intermediate resonator 6, the self-resonant frequency is mutual resonant frequency by the mutual inductance between the sixth intermediate resonator and a receiver (f ₃ Is changed to).

When the wireless power transmitter 60 transmits the power having the mutual resonance frequency f ₃ toward the relay resonator 70, only the sixth resonator of the relay resonator 70 may receive the mutual resonance frequency ( f ₃ ) magnetic resonance. Thus, only the sixth repeater resonator relays power to the receiving device 80 present thereon.

Since the other relay resonators of the relay resonator 70 have their own resonance frequencies f ₁ , they do not generate magnetic resonance with respect to the mutual resonance frequency f ₃ . Therefore, the wireless power transmitter 60 only transmits relatively small power to the receiver 80 through the remaining relay resonators.

On the other hand, if the wireless power receiver is not located on the relay resonator 70, all the relay resonators in the relay resonator do not generate magnetic resonance with respect to the mutual resonance frequency f ₃ . Therefore, energy transmission by magnetic resonance is not performed between the wireless power transmitter, the relay resonator, and the wireless power receiver.

As described above, the wireless power transmitter according to the embodiment of the present invention transmits energy through a specific relay resonator corresponding to the position of the wireless power receiver existing on the relay resonator, thereby transmitting the energy to the wireless power receiver. Energy transmission efficiency can be improved.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by equivalents to the appended claims, as well as the appended claims.

10: power source 20: power transmitter
21: transmitting coil portion 22: transmitting resonance coil portion
30: power receiving unit 31: receiving resonance coil unit
32: receiving coil portion 40: rectifier circuit
50: load 60: wireless power transmitter
70: power relay unit 80: wireless power receiver

Claims (17)

A wireless power transmitter for wirelessly transmitting power to a wireless power receiver using resonance,
Relay resonator; And
And a power source configured to transfer AC power having a mutually changed resonance frequency changed by mutual inductance components of the wireless power receiver and the relay resonator to the relay resonator.
Wireless power transmitter. The method of claim 1,
The relay resonator includes a plurality of relay resonators,
The power source,
It is characterized in that for supplying AC power having a mutually changed resonant frequency changed by the mutual inductance component between the wireless power receiver and the relay resonator corresponding to the position of the wireless power receiver among the plurality of relay resonators.
Wireless power transmitter. The method of claim 2,
Resonance frequencies of the plurality of relay resonators and the resonance frequency of the wireless power receiver is characterized in that different from each other
Wireless power transmitter. The method of claim 2,
The mutually altered resonance frequency is determined based on the inductance and capacitance of the repeater resonator corresponding to the position of the wireless power receiver, and the inductance and capacitance of the wireless power receiver.
Wireless power transmitter. The method of claim 2,
The mutually altered resonance frequency (f ₃ ) is calculated as in the following equation.
[Mathematical Expression]

,
Where L ₁ is an inductance value of the repeater resonator corresponding to the position of the wireless power receiver, L ₂ is an inductance value of the wireless power receiver, and C ₁ is a value of the repeater resonator corresponding to the position of the wireless power receiver. Capacitance value, C ₂ is the capacitance value of the wireless power receiver. The method of claim 2,
The mutually altered resonance frequency may vary according to a relative position of the repeater resonator corresponding to the position of the wireless power receiver and the wireless power receiver.
Wireless power transmitter. The method of claim 2,
The plurality of relay resonators are arranged in a grid form or a matrix form in the relay pad
Wireless power transmitter. The method of claim 1,
The relay resonator may be spaced apart from the wireless power transmitter at a predetermined distance.
Wireless power transmitter. The method of claim 1,
The transmitter further includes a transmission unit for transmitting the AC power supplied from the power source to the wireless power receiver through the relay resonator using resonance.
Wireless power transmitter. 10. The method of claim 9,
The transmitting unit,
A transmission coil unit receiving the AC power from the power source to generate a magnetic field; And
And a transmission resonant coil unit coupled to the transmission coil unit to transmit power generated by the generated magnetic field to the relay resonance unit using resonance.
Wireless power transmitter. The method of claim 1,
The wireless power transmitter stores information about the frequency to be changed in advance.
Wireless power transmitter. A wireless power repeater that wirelessly delivers power to a wireless power receiver using resonance,
A plurality of relay resonators,
The wireless power repeater
Characterized in that the AC power having a mutually changed resonance frequency changed by the mutual inductance component of the relay resonator corresponding to the position of the wireless power receiver among the plurality of relay resonators is transmitted to the wireless power receiver.
Wireless power repeater. The method of claim 12,
Resonance frequencies of the plurality of relay resonators and the resonance frequency of the wireless power receiver is characterized in that different from each other
Wireless power repeater. The method of claim 12,
The mutually altered resonance frequency is determined based on the inductance and capacitance of the repeater resonator corresponding to the position of the wireless power receiver, and the inductance and capacitance of the wireless power receiver.
Wireless power repeater. The method of claim 12,
The mutually altered resonance frequency (f ₃ ) is calculated as in the following equation.
[Mathematical Expression]

,
Wherein L ₁ is an inductance value of the repeater resonator corresponding to the position of the wireless power receiver, L ₂ is an inductance value of the wireless power receiver, and C ₁ is a value of the repeater resonator corresponding to the position of the wireless power receiver. Capacitance value, C ₂ is the capacitance value of the wireless power receiver. The method of claim 12,
The mutually altered resonance frequency may vary according to a relative position of the repeater resonator corresponding to the position of the wireless power receiver and the wireless power receiver.
Wireless power repeater. The method of claim 12,
The plurality of relay resonators are arranged in a grid form or a matrix form in the relay pad
Wireless power repeater.

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