KR20110134971A - Apparatus and method for transmit power beamforming using sub-transmitter in wireless power transmission systems - Google Patents

Abstract

PURPOSE: A power transmission beam-forming apparatus and method thereof are provided to remove electromagnetic interference to a peripheral device which does not receive power. CONSTITUTION: An information receiving unit(210) receives a wireless power transmission request signal from a target receiver. One or more sub transmission units(220) are prepared in a state that wireless power is transmitted in case a wireless power transmission request signal is received. One or more sub transmission units transmits wireless power which is received from a main transmission unit(230) to the target receiver. The main transmission unit transmits wireless power to the target receiver through the sub transmission unit.

Description

Apparatus and method for transmitting power beamforming using secondary transmitter in wireless power transmission system {APPARATUS AND METHOD FOR TRANSMIT POWER BEAMFORMING USING SUB-TRANSMITTER IN WIRELESS POWER TRANSMISSION SYSTEMS}

TECHNICAL FIELD The art relates to an apparatus and method for beamforming transmit power in a wireless power transfer system.

The research on wireless power transmission has begun to overcome the inconvenience of wired power supply due to the explosive increase of various electric devices including mobile devices and the limitation of existing battery capacity.

However, in the wireless power transmission system, the reception of power decreases as the distance between the power transmitter and the power receiver increases, and when the transmission / reception period becomes longer than a specific distance, power transmission and reception and data communication become almost impossible. . Therefore, when the power receiver is located outside the power transmission / reception area (hereinafter, referred to as a “transmission area”), wireless power transmission is impossible.

In addition, in the wireless power transmission system, the electromagnetic signal from the power transmitter may cause an electromagnetic interference effect on a peripheral device that does not want to receive power. In other words, electromagnetic fields related to electromagnetic fields, such as magnetic fields emitted from power transmitters, may affect not only power receivers intended to receive power, but also peripheral devices that do not want to receive power. The interference caused by the electromagnetic energy on the peripheral device is called electromagnetic interference (EMI). Electromagnetic interference can interfere with the normal operation of peripherals or cause unwanted power reception, noise and various disturbances.

In one aspect, the apparatus for transmitting power beamforming is provided with an information receiver for receiving a wireless power transmission request signal from a target receiver, and ready to perform wireless power transmission when the wireless power transmission request signal is received, and received from a main transmitter. And at least one sub transmitter configured to transfer the wireless power to the target receiver, and a main transmitter configured to transmit wireless power to the target receiver through the sub transmitter based on the wireless power transmission request signal.

The sub-transmitter wakes up when receiving the power transmission request signal from the target receiver, and may be maintained in a sleep mode when the power transmission request is not received.

The sub-transmitter is an information receiving unit for receiving a power transmission request signal from the target receiver, a state preparation unit ready for power transmission when the request signal is received, and powers to the main transmission unit if the power transmission is ready. A transmission request signal transmission unit for transmitting a transmission request signal and a relay unit for receiving the power from the main transmission unit and delivers to the target receiver.

The main transmitter may start power transmission when the transfer power transmission request signal is received.

The information receiver receives position information of the target receiver, and the main transmitter transmits power directly without using the sub transmitter when the target receiver is located in a transmission area of the main transmitter based on the received position information. Can be performed.

The target receiver includes: a search unit searching for the sub transmitter closest to the target receiver, an information transmitter transmitting a power transmission request signal to the searched sub transmitter, and power receiving power from the sub transmitter receiving the request signal. It may include a receiver.

The search unit searches for the sub transmitter closest to the target receiver through in-band communication or out of band communication, and when searching through the out of band communication, the sub transmitter. And the location information of the target receiver may be exchanged to be transmitted to the transmission region of the sub transmitter.

In one aspect, the apparatus for beamforming power transmission forms an information receiver configured to receive a power transmission request signal and position information of the target receiver from a target receiver, and forms a straight line between the target receiver and the main transmitter based on the received position information. And a main transmitter for transmitting power through the sub transmitter based on the received power transmission request signal.

The sub transmitter may be connected to the main transmitter in a straight line and rotate 360 degrees with respect to the main transmitter.

The main transmitter may rotate the sub transmitter to be in a straight line between the target receiver and the main transmitter based on the position information of the target receiver.

The main transmitter may directly perform power transmission without using the sub transmitter when the target receiver is located in a transmission area of the main transmitter based on the position information of the target receiver.

In one aspect, the method of transmitting power beamforming includes receiving a wireless power transmission request signal from a target receiver, and when the wireless power transmission request signal is received, is prepared to be in a state capable of wireless power transmission and is received from a main transmitter. And transmitting wireless power to the target receiver based on the wireless power transmission request signal based on the wireless power transmission request signal.

In one aspect, a method of transmitting power beamforming includes receiving a power transmission request signal and location information of a target receiver from a target receiver, and forming a straight line between the target receiver and a main transmitter based on the received location information. And transmitting power through the sub-transmitter based on the received power transmission request signal.

A transmission power beamforming apparatus using a plurality of secondary transmitters and a transmission power beamforming apparatus using a rotatable secondary transmitter increase the distance at which power transmission and reception are possible.

In addition, a transmission power beamforming apparatus using a plurality of secondary transmitters and a transmission power beamforming apparatus using a rotatable secondary transmitter eliminate and mitigate electromagnetic interference on peripheral devices that do not want power reception.

1 is a block diagram of a power transmission apparatus using a moving body according to one side.
2 is a block diagram of a transmission power beamforming apparatus in a wireless power transmission system according to one side.
3 is a view illustrating the use of a plurality of sub transmitters for extending a transmission area and mitigating electromagnetic interference according to one side.
4 is a view illustrating the use of a rotatable secondary transmitter for extending a transmission area and mitigating electromagnetic interference according to one side.
5 is a diagram illustrating a meta-structured resonator according to one side.
FIG. 6 is a diagram illustrating an equivalent circuit of the resonator illustrated in FIG. 5.
7 is a diagram illustrating a meta-structured resonator according to another side.
8 is a view illustrating in detail the insertion position of the capacitor of FIG.
9 is a flowchart illustrating a transmission power beamforming method using a secondary transmitter in a wireless power transmission system according to one side.
10 is a flowchart illustrating a transmission power beamforming method using a movable sub transmitter in a wireless power transmission system according to one side.

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

First, the wireless power transmission technology used in the wireless power transmission system will be described. Wireless power transmission technology can be classified into three types of electromagnetic induction method, radio wave reception method, electric field or magnetic field resonance method.

First, the electromagnetic induction method uses a phenomenon in which magnetic flux is generated when an alternating current flows in one coil after approaching two different coils close to each other, and thus electromotive force is generated in the other coil. The electromagnetic induction method has the most high efficiency and practical use, such as the power utilization efficiency is approximately 60-98%.

Second, in the radio wave reception method, radio wave energy is received and used by an antenna to convert an AC radio wave waveform into a direct current through a rectifier circuit to obtain power. Radio reception method is capable of transmitting wireless power over the longest distance (above several meters).

Third, the resonance method uses resonance of an electric field or a magnetic field, and transmits energy by resonating at the same frequency between devices. In case of using the resonance of the magnetic field, electric power is generated by using magnetic resonance coupling using the LC resonator structure. The magnetic resonance method is a technology that uses a near field effect of a short distance compared to the wavelength of the used frequency. Unlike the radio wave reception method, it is a non-radiative energy transmission, and matches the resonance frequency between the transmitter and the receiver. Send it. The magnetic resonance method increases the power transmission efficiency by about 50 ~ 60%, which is much higher than the radio wave reception type through radio wave radiation. Although the transmission / reception period distance is about several meters, although the technique used in the near field rather than the radio wave reception method, the power transmission is possible at a far distance than the electromagnetic induction type within a few mm.

1 is a diagram illustrating a wireless power transmission system according to one side.

In the example of FIG. 1, it is assumed that the wireless power transmitted through the wireless power transmission system is resonance power.

Referring to FIG. 1, a wireless power transmission system is a source-target structure consisting of a source and a target. That is, the wireless power transmission system includes a resonance power transmitter 110 corresponding to a source and a resonance power receiver 120 corresponding to a target.

The resonance power transmitter 110 includes a source unit 111 and a source resonator 115 that generate energy by receiving energy from an external voltage supply device. In this case, the external voltage source may be AC, DC, a battery, or the like. In addition, the resonance power transmission apparatus 110 may further include a matching control 113 that performs resonance frequency or impedance matching. In addition, the resonance power transmitter 110 may transmit data to the resonance power receiver 120 using the resonance frequency band.

The source unit 111 receives energy from an external voltage supply to generate resonance power. The source unit 111 rectifies an AC signal output from an AC-AC converter or an AC-AC converter for adjusting a signal level of an AC signal input from an external device to a desired level, thereby outputting a DC voltage having a predetermined level. It can include a DC-AC Inverter that generates an AC signal of several MHz to several tens of MHz band by fast switching the DC voltage output from the DC converter and the AC-DC converter. In addition, the source unit 111 may transmit the idle power to the target unit 125 while moving through the moving object rather than at a fixed position. For example, the source unit 111 may be included in a moving robot device.

The matching control 113 sets the resonance bandwidth of the source resonator 115 or the impedance matching frequency of the source resonator 115. The matching control unit 113 includes at least one of a source resonance bandwidth setting unit (not shown) or a source matching frequency setting unit (not shown). The source resonant bandwidth setting unit sets a resonance bandwidth of the source resonator 115. The source matching frequency setting unit sets the impedance matching frequency of the source resonator 115. In this case, the Q-factor of the source resonator 115 may be determined according to the resonance bandwidth of the source resonator or the impedance matching frequency of the source resonator.

The source resonator 115 transfers electromagnetic energy to the target resonator. That is, the source resonator 115 transmits the resonance power to the target device 120 through the magnetic coupling 101 with the target resonator 121. At this time, the source resonator 115 resonates within the set resonance bandwidth.

The resonance power receiver 120 includes a target resonator 121, a matching control unit 123 for performing resonance frequency or impedance matching, and a target unit 125 for transferring the received resonance power to a load. In addition, the resonance power receiver 120 may receive data from the resonance power transmitter 110 using the resonance frequency band.

The target resonator 121 receives electromagnetic energy from the source resonator 115. At this time, the target resonator 121 resonates within the set resonance bandwidth.

The matching control unit 123 sets at least one of a resonance bandwidth of the target resonator 121 or an impedance matching frequency of the target resonator 121. The matching control unit 123 includes at least one of a target resonance bandwidth setting unit (not shown) or a target matching frequency setting unit (not shown). The target resonance bandwidth setting unit sets a resonance bandwidth of the target resonator 121. The target matching frequency setting unit sets the impedance matching frequency of the target resonator 121. In this case, the Q-factor of the target resonator 121 may be determined according to the resonance bandwidth of the target resonator 121 or the impedance matching frequency of the target resonator 121.

The target unit 125 transfers the received resonance power to the load. At this time, the target unit 125 rectifies an AC signal received from the source resonator 115 to the target resonator 121 to generate a DC signal, and an AC-DC converter to adjust the signal level of the DC signal to adjust the device voltage. It may include a DC-DC converter that supplies a device or a load. The load capable of receiving the resonance power includes various home appliances including a digital photo frame, a speaker, a vacuum cleaner, a dryer, a shaver, a laptop PC, a computer, a peripheral device thereof, a mobile phone, a digital camera, a camcorder, an MP3 player, a PDA, and various portable devices. The device, in addition to the femtocell base station, various sensors and lighting equipment may be included.

The source resonator 115 and the target resonator 121 may be configured as a helix coil structure resonator, a spiral coil structure resonator, or a meta-structured resonator. The meta-structured resonator will be described in detail later with reference to FIG. 6.

Referring to FIG. 1, the control process of the cue-factor sets the resonance bandwidth of the source resonator 115 and the resonance bandwidth of the target resonator 121, and the source resonator 115 and the target resonator 121. And transferring electromagnetic energy from the source resonator 115 to the target resonator 121 through magnetic coupling therebetween. In this case, the resonance bandwidth of the source resonator 115 may be set to be wider or narrower than the resonance bandwidth of the target resonator 121. That is, since the resonance bandwidth of the source resonator 115 is set wider or narrower than the resonance bandwidth of the target resonator 121, the BW-factor of the source resonator and the BW-factor of the target resonator are maintained in an unbalanced relationship with each other. .

In resonant wireless power transmission, the resonance bandwidth is an important factor. When Qt is a Q-factor that considers the distance change between the source resonator 115 and the target resonator 121, the change in the resonance impedance, the impedance mismatch, the reflected signal, and the like, Qt is equal to the resonance bandwidth as shown in Equation 1 below. Have an inverse relationship.

[Equation 1]

는 대역폭,

는 공진기 사이의 반사 손실, BW_S는 소스 공진기(115)의 공진 대역폭, BW_D는 타겟 공진기(121)의 공진 대역폭을 나타낸다. 본 명세서에서 BW-factor는 1/ BW_S 또는 1/BW_D를 의미한다.In Equation 1, f0 is the center frequency,

Is the bandwidth,

Is the reflection loss between the resonators, BW _S is the resonance bandwidth of the source resonator 115, BW _D is the resonance bandwidth of the target resonator 121. In the present specification, the BW-factor means 1 / BW _S or 1 / BW _D.

On the other hand, impedance mismatching between the source resonator 115 and the target resonator 121 may occur due to external influences such as a change in distance between the source resonator 115 and the target resonator 121 or a change in one of the two positions. Can be. Impedance mismatch can be a direct cause of reducing the efficiency of power delivery. The matching control 113 may determine that impedance mismatch has occurred by sensing a reflected wave in which a part of the transmission signal is reflected and return, and perform impedance matching. In addition, the matching control 113 may change the resonance frequency by detecting the resonance point through the waveform analysis of the reflected wave. Here, the matching control 113 may determine a frequency having a minimum amplitude as the resonance frequency in the waveform of the reflected wave.

That is, the resonant power transmitter 110 may exchange not only power but also data with the resonant power receiver 120, and may simultaneously use the power transmission frequency band or use a separate independent frequency band. The resonance power receiver 120 receives power and supplies the load to the load. In this case, the energy field emitted from the resonance power transmitter 110 may have various unnecessary effects on the peripheral system.

2 is a block diagram of a transmission power beamforming apparatus in a wireless power transmission system according to one side. The wireless power receiver includes a target receiver.

Referring to FIG. 2, a transmission power beamforming apparatus according to one side includes an information receiver 210, a sub transmitter 220, and a main transmitter 230.

The information receiver 210 receives a wireless power transmission request signal from a target receiver. The target receiver finds the closest transmitter around it through in-band or out-of-band communication. Here, the in-band refers to the same frequency band as the resonant frequency bands of the main transmitter 230 and the sub transmitter 220, and the out of band refers to a separate frequency band instead of the resonant frequency band. it means. When the target receiver finds a transmitter, the target receiver transmits a wireless power transmission request signal to the transmitter. Therefore, the information receiver 210 receives the wireless power transmission request signal. In addition, the information receiver 210 may receive location information of the target receiver.

In addition, when receiving the wireless power transmission request signal, the sub transmitter 220 is prepared in a state capable of wireless power transmission, and transfers the wireless power received from the main transmitter to the target receiver. The sub transmitter 220 is activated (wake-up) only when the wireless power transmission request signal is received and is ready for power transmission. Here, the wireless power transmission request signal may be received by the information receiver 210 or may be received by a receiver separately installed in the sub transmitter 220. The state in which power transmission is possible means that power is received from the main transmitter and is ready to be delivered to the target receiver.

In addition, the sub-transmitter 220 is located in at least one power transmission region capable of transmitting power of the main transmitter and is activated when the power transmission request signal is received from the target receiver. It stays in sleep mode. The at least one sub transmitter 220 located in the transmission region of the main transmitter receives and activates the power transmission request signal only when it is closest to the target receiver. That is, since only the sub transmitter 220 closest to the target receiver is activated, the sub transmitter 220 receives power from the main transmitter 230 and transmits the power. Therefore, the power transmission distance is extended by the power transmission area of the sub transmitter 220, and power beamforming is possible between the main transmitter, the sub transmitter, and the target receiver. When the sub transmitter 220 located in the direction of the target receiver is activated, the power of the main transmitter 230 is magnetic resonance coupled to the sub transmitter 220, and the power of the sub transmitter 220 is again supplied to the target receiver. Coupling Accordingly, the distance in which magnetic resonance coupling occurs in the direction in which the sub transmitter 220 is turned on increases. On the other hand, since the sub-transmitter 220 is turned off in the direction of the other sub-transmitter 220, the power transmission distance does not increase. Here, the sub transmitter 220 may be implemented such that AC power is not connected to the main transmitter 230. This is because the main transmitter 230 may retransmit as it is by utilizing the power (coupling) coupled.

Here, the power beamforming concept is slightly different from the data beamforming concept used in the conventional smart antenna system. That is, in the conventional smart antenna system, a method of transmitting and receiving data in a desired direction by controlling each phase in an array of antennas arranged in plural, but power beamforming transmits and receives "power" in a desired direction, not data. Way. Of course, considering the case of simultaneously transmitting data through the frequency band used as power transmission can be considered a similar concept. However, in the smart antenna system, when the signal is transmitted through the phase control of the antenna, it is transmitted in a specific direction through "electromagnetic radiation" in the "far field" region, but the power beamforming method uses an energy field such as a magnetic field in the "near field" region. It is intended to form in a particular direction in a "non-radiative" form.

Also, the sub transmitter 220 moves to a position (to a position of the shortest distance with the target receiver) between the target receiver and the main transmitter 230 based on the received position information of the target receiver. Since the secondary transmitter 220 recognizes the position of the target receiver, the secondary transmitter 220 and the secondary transmitter 220 and the target receiver may move in a straight line. The sub transmitter 220 may move using the moving object. The moving body may include a robot device. In addition, the sub-transmitter 220 may be placed on a disk-shaped rotating plate centering on the main transmitting unit 230, and the rotating plate may rotate to be in line with the target receiver. In addition, the sub transmitter 220 may be connected to the main transmitter 230 in a straight axis to rotate 360 degrees with respect to the main transmitter to form a straight line with the target receiver. In this case, the rotation of the sub transmitter 220 may be performed by the command of the sub transmitter 220 based on the position information of the target receiver, or may be performed by the rotation command of the main transmitter 230.

In addition, the sub-transmitter 220 is an information receiver for receiving a power transmission request signal from a target receiver, a state preparation unit that is prepared to enable power transmission when the request signal is received, and if the power transmission is ready to the state A transmission request signal transmitter for transmitting a power transmission request signal to a transmitter and a relay unit for receiving the power from the main transmitter to deliver to the target receiver.

In addition, the main transmitter 230 transmits wireless power to the target receiver through the sub transmitter based on the wireless power transmission request signal. Since the main transmitter 230 transmits wireless power to the target receiver through the sub transmitter, power beamforming is possible. In addition, the main transmitter 230 may start power transmission when the wireless power transmission request signal is received. When the primary transmitter 230 is in a standby state and the information transmitter 210 or the secondary transmitter 220 receives the wireless power transmission request signal from the target receiver, the primary transmitter 230 is activated to transmit power to the secondary transmitter 220. Can be. In addition, when the target receiver is located in the transmission region of the main transmitter 230 based on the location information of the target receiver received by the information receiver 210, the main transmitter 230 may not directly use the sub transmitter 220. Power transfer can be performed. Also, the main transmitter 230 may rotate the sub transmitter 220 to be in a straight line between the target receiver and the main transmitter 230 based on the location information of the target receiver. The primary transmitter 230 and the secondary transmitter 230 can match the directions of the antennas with each other, so that the best coupling can occur, thus maximizing the strength of the power beamforming.

The target receiver may further include: a searcher for searching for a sub transmitter 220 closest to the target receiver, an information transmitter for transmitting a wireless power transmission request signal to the searched sub transmitter 220, and the receiver having received the request signal. It may include a power receiver for receiving power from the transmitter 220. The search unit may exchange data with the sub transmitter 220 through the in-band. The data may include location information of the target receiver and a wireless power transmission request signal. The searcher may search the sub transmitter 220 closest to the target receiver through the exchange of data. Also, the searcher may search for the sub transmitter 220 closest to the target receiver through out of band communication. When the searcher searches through the out-of-band communication, the sub-transmitter 220 and the target receiver may be guided to the transmission region of the sub-transmitter 220 by exchanging location information of the target receiver through the out-of-band communication. The information transmitter transmits the data to the sub transmitter 220, and the sub transmitter 220 receives power from the main transmitter 230 and transmits the power to the power receiver.

3 is a view illustrating the use of a plurality of sub transmitters for extending a transmission area and mitigating electromagnetic interference according to one side.

If the distance between the main transmitter 230 and the target receiver is far away or power transmission is not desired to the peripheral device in a different direction, that is, to reduce the influence of electromagnetic interference on the peripheral device, a plurality of secondary transmitters 220 around the main transmitter 230 may be used. ) By installing and operating the wake-up of the sub-transmitter 220 located in the target receiver direction to enable power transmission and reception. Referring to FIG. 3, the target receiver searches for the sub-transmitter 1 located closest, and the target receiver activates the sub-transmitter 1 by transmitting a wireless power transmission request signal to the sub-transmitter 1. The activated secondary transmitter 1 receives power from the primary transmitter and delivers power to the target receiver. Therefore, the power transmission distance of the main transmitter is extended in the direction of the sub transmitter 1.

4 is a view illustrating the use of a rotatable secondary transmitter for extending a transmission area and mitigating electromagnetic interference according to one side.

If the distance between the main transmitter 230 and the target receiver is not far or power transmission is not desired, the sub transmitter connected to the main transmitter 230 in a straight axis is installed and mechanically rotatable so that the target receiver can be rotated. Power transmission and reception are enabled. When the target receiver searches for the secondary transmitter 220, the primary transmitter 230 may rotate so that the secondary transmitter 220 and the target receiver are located in the same direction so that the best coupling occurs. The strength of the power beamforming can be maximized.

5 is a diagram illustrating a meta-structured resonator according to one side.

Referring to FIG. 5, the meta-structured resonator includes a transmission line 510 and a capacitor 520. Here, the capacitor 520 is inserted in series at a specific position of the transmission line 510, and the electric field is trapped in the capacitor.

In addition, as shown in FIG. 5, the meta-structured resonator has a form of a three-dimensional structure. Unlike the illustrated in FIG. 5, the resonator may be implemented in a two-dimensional structure in which transmission lines are arranged in x and z planes.

The capacitor 520 is inserted into the transmission line 510 in the form of a lumped element and a distributed element, for example, an interdigital capacitor or a gap capacitor centered on a substrate having a high dielectric constant. As the 520 is inserted into the transmission line 510, the resonator may have a metamaterial characteristic.

Here, the metamaterial is a material having special electrical properties that cannot be found in nature, and has an artificially designed structure. The electromagnetic properties of all materials in nature have inherent permittivity or permeability, and most materials have positive permittivity and positive permeability. In most materials, the right-hand rule applies to electric fields, magnetic fields and pointing vectors, so these materials are called RHM (Right Handed Material). However, metamaterials are materials with a permittivity or permeability of less than 1, and according to the sign of permittivity or permeability, ENG (epsilon negative) material, MNG (mu negative) material, DNG (double negative) material, NRI (negative refractive index) Substances, and left-handed (LH) substances.

At this time, when the capacitance of the capacitor inserted as the lumped element is properly determined, the resonator may have the characteristics of the metamaterial. In particular, by appropriately adjusting the capacitance of the capacitor, the resonator may have a negative permeability, so that the resonator according to an embodiment of the present invention may be referred to as an MNG resonator.

The MNG resonator may have a zero-order resonance characteristic having a frequency when the propagation constant is 0 as a resonance frequency. Since the MNG resonator may have a zeroth resonance characteristic, the resonant frequency may be independent of the physical size of the MNG resonator. That is, as will be described again below, in order to change the resonant frequency in the MNG resonator, it is sufficient to design the capacitor appropriately, so that the physical size of the MNG resonator may not be changed.

In addition, in the near field, the electric field is concentrated on the series capacitor 520 inserted into the transmission line 510, so that the magnetic field is dominant in the near field due to the series capacitor 520.

In addition, the MNG resonator may have a high Q-Factor using the capacitor 520 to the lumped element, thereby improving the efficiency of power transmission.

In addition, the MNG resonator may include a matcher 530 for impedance matching. At this time, the matcher 530 properly tunable the strength of the magnetic field for coupling with the MNG resonator, and the impedance of the MNG resonator is adjusted by the matcher 530. The current flows into or out of the MNG resonator through the connector 540.

In addition, although not explicitly illustrated in FIG. 5, a magnetic core penetrating the MNG resonator may be further included. Such a magnetic core may perform a function of increasing a power transmission distance.

The characteristics of the MNG resonator of the present invention will be described in detail below.

FIG. 6 is a diagram illustrating an equivalent circuit of the resonator illustrated in FIG. 5.

The resonator shown in FIG. 5 may be modeled with the equivalent circuit shown in FIG. 6. In the equivalent circuit of FIG. 6, C _L represents a capacitor inserted in the form of a lumped element at the interruption of the transmission line of FIG. 5.

를 공진 주파수로 갖는다고 가정한다. 이 때, 공진 주파수

는 하기 수학식 2와 같이 표현될 수 있다. 여기서, MZR은 Mu Zero Resonator를 의미한다.
At this time, the resonator for wireless power transmission shown in FIG. 5 has a zeroth resonance characteristic. That is, when the propagation constant is 0, the resonator for wireless power transmission

Suppose we have a resonant frequency. At this time, the resonance frequency

May be expressed as Equation 2 below. Here, MZR means Mu Zero Resonator.

[Equation 2]

는

에 의해 결정될 수 있고, 공진 주파수

와 공진기의 물리적인 사이즈는 서로 독립적일 수 있음을 알 수 있다. 따라서, 공진 주파수

와 공진기의 물리적인 사이즈가 서로 독립적이므로, 공진기의 물리적인 사이즈는 충분히 작아질 수 있다.
Referring to Equation 2, the resonant frequency of the resonator

Is

Can be determined by the resonant frequency

It can be seen that the physical size of the and the resonator may be independent of each other. Thus, resonant frequency

Since the physical sizes of the and resonators are independent of each other, the physical sizes of the resonators can be sufficiently small.

7 is a diagram illustrating a meta-structured resonator according to another side.

Referring to FIG. 7, the meta-structured resonator includes a transmission line unit 710 and a capacitor 720. In addition, the resonator according to an embodiment of the present disclosure may further include a feeding unit 730.

In the transmission line unit 710, a plurality of transmission line sheets are arranged in parallel. A configuration in which a plurality of transmission line sheets are arranged in parallel will be described in more detail with reference to FIG. 8.

The capacitor 720 is inserted at a specific position of the transmission line unit 710. In this case, the capacitor 720 may be inserted in series at the interruption of the transmission line unit 710. At this time, the electric field generated in the resonator is trapped in the capacitor 720.

The capacitor 720 may be inserted into the transmission line unit 710 in the form of a lumped element and a distributed element, for example, an interdigital capacitor or a gap capacitor centered on a substrate having a high dielectric constant. As the capacitor 720 is inserted into the transmission line unit 710, the resonator may have a metamaterial characteristic.

The feeding unit 730 may perform a function of supplying current to the MNG resonator. In this case, the feeding unit 730 may be designed to distribute the current supplied to the resonator evenly to the plurality of transmission line sheets.

8 is a view illustrating in detail the insertion position of the capacitor 720 of FIG.

Referring to FIG. 8, the capacitor 720 is inserted into the interruption portion of the transmission line unit 710. In this case, the interruption portion of the transmission line unit 710 may be open so that the capacitor 720 may be inserted, and each of the transmission line sheets 710-1, 710-2, and 710-n may be formed. It can be configured in the form of parallel to each other at the stop.

9 is a flowchart illustrating a transmission power beamforming method using an auxiliary transmitter in a wireless power transmission system according to one side.

The wireless power transmission system includes a wireless power transmitter corresponding to a source and a wireless power receiver corresponding to a target.

The source receives a wireless power transmission request signal from a target receiver, and when the wireless power transmission request signal is received, the source is ready to perform wireless power transmission. Transmits to the target receiver.

Referring to FIG. 9, the target receiver searches for the nearest sub-transmitter 910, and when the closest sub-transmitter is found, transmits a wireless power transmission request signal to the sub-transmitter 920. When the found sub-transmitter receives the wireless power transmission request signal, it is ready to be power-transmitted and wakes up (930). The secondary transmitter transmits a wireless power transfer request signal to the primary transmitter 940, and the primary transmitter transmits power 950 to the secondary transmitter. The secondary transmitter transmits the power received from the primary transmitter to the target receiver (960).

10 is a flowchart illustrating a transmission power beamforming method using a movable sub transmitter in a wireless power transmission system according to one side.

The wireless power transmission system includes a wireless power transmitter corresponding to a source and a wireless power receiver corresponding to a target.

The source receives the wireless power transmission request signal and the location information of the target receiver from a target receiver, moves to a straight line between the target receiver and the main transmitter based on the received location information, and receives the received wireless power. Power is transmitted through the sub transmitter based on the transmission request signal.

Referring to FIG. 10, the target receiver searches for the closest sub transmitter 1001 or the main transmitter 1003, and detects its location to generate location information (1005). The target receiver transmits the position information 1007 and the power transmission request signal 1009 to the secondary transmitter, and the secondary transmitter transmits the position information 1011 and the power transmission request signal 1013 of the received target receiver to the primary transmitter. . The secondary transmitter moves 1015 to a position in line with the primary transmitter and the target receiver to prepare for power beamforming. The primary transmitter transmits power to the secondary transmitter in response to the received power transmission request signal (1017), and the secondary transmitter receives power and transmits the power to the target receiver (1019).

Methods according to an embodiment of the present invention can be implemented in the form of program instructions that can be executed by various computer means and recorded in a computer readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on the media may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts.

As described above, the present invention has been described by way of limited embodiments and drawings, but the present invention is not limited to the above embodiments, and those skilled in the art to which the present invention pertains various modifications and variations from such descriptions. This is possible.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the claims below but also by the equivalents of the claims.

Claims (13)

An information receiver configured to receive a wireless power transmission request signal from a target receiver;
At least one secondary transmitter configured to be ready for wireless power transmission when the wireless power transmission request signal is received, and to transmit wireless power received from a primary transmitter to the target receiver; And
A main transmitter for transmitting wireless power to the target receiver through the sub transmitter based on the wireless power transmission request signal;
Transmission power beamforming apparatus comprising a. The method of claim 1,
The sub-transmitter,
And a wake-up upon receiving a power transmission request signal from the target receiver, and in a sleep mode when the power transmission request is not received. The method of claim 1,
The sub-transmitter,
An information receiver configured to receive a power transmission request signal from the target receiver;
A state preparation unit ready to receive power when receiving the request signal;
A transmission request signal transmitting unit which transmits a power transmission request signal to the main transmission unit when the power transmission is prepared in a possible state; And
A relay unit receiving power from the main transmitter and transferring the power to the target receiver
Transmission power beamforming apparatus comprising a. The method of claim 1,
The main transmission unit,
And transmitting power when the wireless power transmission request signal is received. The method of claim 1,
The information receiver receives the location information of the target receiver,
And the main transmitter performs direct power transmission without using the sub transmitter when the target receiver is located in a transmission area of the main transmitter based on the received position information. The method of claim 1,
The target receiver
A searcher searching for the sub-transmitter closest to the target receiver
An information transmitter for transmitting a wireless power transfer request signal to the found secondary transmitter
A power receiver for receiving power from the sub-transmitter receiving the request signal
Transmission power beamforming apparatus comprising a. The method of claim 6,
The search unit searches for the sub transmitter closest to the target receiver through in-band communication or out of band communication.
And a case of searching through the out-of-band communication, the position information of the sub transmitter and the target receiver is exchanged to be guided to the transmission region of the sub transmitter. An information receiver configured to receive a wireless power transmission request signal and location information of the target receiver from a target receiver;
A sub transmitter configured to move to a position in a straight line between the target receiver and the main transmitter based on the received position information; And
A main transmitter for transmitting power through the sub transmitter based on the received wireless power transmission request signal
Transmission power beamforming apparatus comprising a. The method of claim 8,
The sub-transmitter,
The transmission power beamforming apparatus connected to the main transmission unit in a straight axis and rotated 360 degrees with respect to the main transmission unit. The method of claim 8,
The main transmission unit,
And a sub power transmitter rotating the sub transmitter so as to be in a straight line between the target receiver and the main transmitter based on the position information of the target receiver. The method of claim 8,
The main transmission unit,
And a target power transmitter based on the position information of the target receiver, when the target receiver is located in a transmission region of the main transmitter, directly performing power transmission without using the sub transmitter. Receiving a wireless power transmission request signal from a target receiver;
Preparing to perform a wireless power transmission when the wireless power transmission request signal is received; And
Transmitting wireless power to the target receiver through a sub-transmitter based on the wireless power transmission request signal;
Transmission power beamforming method comprising a. Receiving a wireless power transmission request signal and location information of the target receiver from a target receiver;
Moving to a straight line between the target receiver and the main transmitter based on the received position information; And
Transmitting power through a sub-transmitter based on the received wireless power transmission request signal;
Transmission power beamforming method comprising a.

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