WO2018021666A1

WO2018021666A1 - Apparatus and method for controlling wireless power transmission using near field communication

Info

Publication number: WO2018021666A1
Application number: PCT/KR2017/005367
Authority: WO
Inventors: 박유리
Original assignee: 엘지이노텍(주)
Priority date: 2016-07-28
Filing date: 2017-05-24
Publication date: 2018-02-01
Also published as: KR20180012962A

Abstract

The present invention relates to an apparatus and a method for controlling wireless power transmission using Near Field Communication (NFC). A method for controlling a wireless power transmitter according to one embodiment of the present invention may comprise the steps of: transmitting a first Near Field Communication (NFC) signal having a driving power of a communication unit included in a wireless power receiver; recognizing the wireless power receiver through a response signal to the first Near Field Communication signal; transmitting a second Near Field Communication signal for establishing a Near Field Communication (NFC) channel as a communication channel for a wireless power transmission to the communication unit; and transmitting and receiving a state information signal related to a wireless power transmission and reception through the established Near Field Communication channel.

Description

Wireless power transmission control device and method using local area communication

The present invention relates to wireless power transmission, and more particularly, to an apparatus and method for controlling a wireless power transceiver using Near Field Communication (NFC).

Portable terminals such as mobile phones and laptops include a battery that stores power and circuits for charging and discharging the battery. In order for the battery of the terminal to be charged, power must be supplied from an external charger.

In general, as an example of an electrical connection method between a charging device and a battery for charging power to a battery, the terminal is supplied with commercial power and converted into a voltage and a current corresponding to the battery to supply electrical energy to the battery through the terminal of the battery. Supply method. This terminal supply method is accompanied by the use of a physical cable (cable) or wire. Therefore, when handling a lot of terminal supply equipment, many cables occupy considerable working space, are difficult to organize, and are not good in appearance. In addition, the terminal supply method may cause problems such as instantaneous discharge phenomenon due to different potential difference between the terminals, burnout and fire caused by foreign substances, natural discharge, deterioration of battery life and performance.

Recently, in order to solve this problem, a charging system (hereinafter referred to as a "wireless charging system") and a control method using a method of transmitting power wirelessly have been proposed. In addition, since the wireless charging system was not pre-installed in some terminals in the past and the consumer had to separately purchase a wireless charging receiver accessory, the demand for the wireless charging system was low, but the number of wireless charging users is expected to increase rapidly. It is expected to be equipped with a charging function.

In general, the wireless charging system includes a wireless power transmitter for supplying electrical energy through a wireless power transmission method and a wireless power receiver for charging the battery by receiving the electrical energy supplied from the wireless power transmitter.

The wireless charging system may transmit power by at least one wireless power transmission method (eg, electromagnetic induction method, electromagnetic resonance method, RF wireless power transmission method, etc.).

For example, the wireless power transmission scheme may use various wireless power transmission standards based on an electromagnetic induction scheme that generates a magnetic field in the power transmitter coil and charges using an electromagnetic induction principle in which electricity is induced in the receiver coil under the influence of the magnetic field. . Here, the electromagnetic induction wireless power transmission standard may include an electromagnetic induction wireless charging technology defined by the Wireless Power Consortium (WPC) or / and the Power Matters Alliance (PMA).

As another example, the wireless power transmission method may use an electromagnetic resonance method of transmitting power to a wireless power receiver located in close proximity by tuning a magnetic field generated by a transmission coil of the wireless power transmitter to a specific resonance frequency. . Here, the electromagnetic resonance method may include a wireless charging technology of a resonance method defined in an A4WP (Alliance for Wireless Power) standard device, which is a wireless charging technology standard device.

As another example, the wireless power transmission method may use an RF wireless power transmission method that transmits power to a wireless power receiver located at a far distance by putting energy of low power in an RF signal.

Meanwhile, the wireless power transceiver may use out-of-band communication using a separate Bluetooth communication to control wireless power transmission.

In this regard, Korean Patent Application No. 10-2013-7033209 (a receiver for receiving wireless power and a method for receiving wireless power thereof) has a coil for receiving power energy and a coil provided separately from the outside of the coil to provide NFC (Near Field Communication). A receiver for a wireless charging system has been disclosed that includes a coil.

By using an antenna in which the NFC coil and the wireless power transceiver coil are integrally formed, a method of detecting the wireless power receiver using NFC communication may be added or replaced in addition to the method of detecting the wireless power receiver using Bluetooth communication. In addition, NFC communication may be used for power transmission control as well as pairing between wireless power transceivers.

Accordingly, there is a need for a method of detecting a wireless power receiver using NFC communication and a specific method of pairing with the detected wireless power receiver.

The present invention has been devised to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide an apparatus and method for controlling wireless power transmission using near field communication (NFC).

The present invention uses the NFC signal to search for a wireless power transceiver, wireless power transmission using near field communication (NFC communication) that can be more quickly transfer power when using the Bluetooth communication only NFC tagging (NFC Tagging) between the wireless power transceiver It is to provide a control apparatus and method.

Technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned above will be clearly understood by those skilled in the art from the following description. Could be.

In order to solve the above technical problem, the wireless power transmitter control method according to an embodiment of the present invention, the first near field communication (Near Field Communication, NFC) signal having a driving power of the communication unit included in the wireless power receiver Transmitting; Recognizing the wireless power receiver through a response signal to the first short range communication signal; Transmitting a second near field communication signal for establishing a near field communication (NFC) channel as a communication channel for wireless power transmission with the communication unit; And transmitting and receiving status information signals related to wireless power transmission and reception through the established short range communication channel. It may include.

According to an embodiment, the first short range communication signal may be a signal for periodically searching for an NFC tag included in the wireless power receiver.

According to an embodiment, the communication unit may include an NFC module configured to perform near field communication (NFC); And a Bluetooth module configured to perform Bluetooth communication. It may include.

According to an embodiment, the method may further include: activating any one of an NFC module performing near field communication (NFC) and a Bluetooth module performing Bluetooth communication according to the strength of the second near field communication signal; It may further include.

According to an embodiment, the transmitting and receiving of the status information signal may be performed at regular intervals.

In addition, the wireless power receiver control method according to an embodiment of the present invention, transmitting a first Near Field Communication (NFC) signal for searching for a wireless power transmitter; Recognizing the wireless power transmitter through a response signal to the first short range communication signal; Transmitting a second near field communication signal to establish a near field communication (NFC) channel as a communication channel for receiving wireless power from the wireless power transmitter; And transmitting and receiving status information signals related to wireless power transmission and reception through the established short range communication channel. It may include.

According to an embodiment, the first short range communication signal may be a signal for periodically searching for an NFC tag included in the wireless power transmitter.

According to an embodiment, the method may further include: activating one of an NFC module performing near field communication (NFC) and a Bluetooth module performing Bluetooth communication according to the strength of the second near field communication signal; It may further include.

According to an embodiment, the present invention can provide a computer readable recording medium having recorded thereon a program for executing the method described above.

In addition, the wireless power transmitter according to an embodiment of the present invention, the second communication unit for transmitting a first Near Field Communication (Near Field Communication, NFC) signal having a driving power of the first communication unit included in the wireless power receiver; And a transmitter control unit recognizing the wireless power receiver through a response signal to the first short range communication signal. Wherein the second communication unit transmits a second short range communication signal for establishing a near field communication (NFC) channel as a communication channel for wireless power transmission with the first communication unit, and wireless power through the established short range communication channel. Transmit and receive status information signals related to transmission and reception.

According to an embodiment, the second communication unit may include an NFC module for performing near field communication (NFC); And a Bluetooth module for performing Bluetooth communication. It may include.

According to an embodiment, the transmitter control unit may activate any one of an NFC module performing near field communication (NFC) and a Bluetooth module performing Bluetooth communication according to the strength of the second near field communication signal.

According to an embodiment, the second communication unit may transmit and receive the state information at regular intervals.

According to an embodiment, the antenna is formed integrally with the NFC coil and the transmitting coil; It may further include.

In addition, the wireless power receiver according to an embodiment of the present invention, a communication unit for transmitting a first Near Field Communication (Near Field Communication, NFC) signal for searching for a wireless power transmitter; And a receiver controller recognizing the wireless power transmitter through a response signal to the first short range communication signal. The communication unit transmits a second short range communication signal for establishing a near field communication (NFC) channel as a communication channel for receiving wireless power from the wireless power transmitter, and transmits and receives wireless power through the established short range communication channel. It can transmit and receive the relevant status information signal.

According to an embodiment, the receiver controller may activate any one of an NFC module performing near field communication (NFC) and a Bluetooth module performing Bluetooth communication according to the strength of the second near field communication signal.

According to an embodiment, the communication unit may transmit and receive the status information signal at regular intervals.

The above aspects of the present invention are only some of the preferred embodiments of the present invention, and various embodiments in which the technical features of the present invention are reflected will be described in detail below by those skilled in the art. Can be derived and understood.

The effects of the apparatus and method for wireless power transmission control using Near Field Communication (NFC) according to the present invention are as follows.

First, the present invention takes less time to set up by using NFC communication than when pairing using Bluetooth communication.

Second, the present invention can detect a wireless power receiver using NFC communication in an environment in which Bluetooth communication is poor.

Third, the present invention can transfer signals and information other than the standard for wireless power transmission defined by the standards body by using NFC communication.

The effects obtainable in the present invention are not limited to the above-mentioned effects, and other effects not mentioned above may be clearly understood by those skilled in the art from the following description. will be.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings are provided to facilitate understanding of the present invention, and provide embodiments of the present invention together with the detailed description. However, the technical features of the present invention are not limited to the specific drawings, and the features disclosed in the drawings may be combined with each other to constitute new embodiments.

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

2 is an equivalent circuit diagram of a wireless power transmission system of an electromagnetic resonance method according to an embodiment of the present invention.

3 is a state transition diagram illustrating a state transition procedure in the wireless power transmitter of the electromagnetic resonance method according to an embodiment of the present invention.

4 is a state transition diagram of an electromagnetic resonance wireless power receiver according to an embodiment of the present invention.

FIG. 5 is a diagram for describing an operation region of an electromagnetic resonance type wireless power receiver based on VRECT according to an exemplary embodiment of the present invention.

6 is a flowchart illustrating a wireless charging procedure of the electromagnetic resonance method according to an embodiment of the present invention.

7 is a flowchart illustrating an operation of a wireless power transmitter and a wireless power receiver supporting a multi-mode wireless power transmission method according to an embodiment of the present invention.

8 is a view for explaining a near field communication (NFC) scheme according to an embodiment of the present invention.

FIG. 9 is a diagram for describing a method of searching for and recognizing a wireless power receiver serving as an NFC target when the wireless power transmitter serves as an NFC initiator according to an embodiment of the present invention.

FIG. 10 illustrates a method for searching for and recognizing a wireless power transmitter that serves as an NFC target when the wireless power receiver serves as an NFC initiator according to an embodiment of the present invention.

11 is a block diagram of a wireless power transmitter including an antenna in which the NFC coil and the wireless charging coil are integrally formed according to an embodiment of the present invention.

Hereinafter, an apparatus and various methods to which embodiments of the present invention are applied will be described in more detail with reference to the accompanying drawings. The suffixes "module" and "unit" for components used in the following description are given or used in consideration of ease of specification, and do not have distinct meanings or roles from each other.

In the above description, all elements constituting the embodiments of the present invention are described as being combined or operating in combination, but the present invention is not necessarily limited to the embodiments. In other words, within the scope of the present invention, all of the components may be selectively operated in combination with one or more. In addition, although all of the components may be implemented in one independent hardware, each or all of the components may be selectively combined to perform some or all functions combined in one or a plurality of hardware. It may be implemented as a computer program having a. Codes and code segments constituting the computer program may be easily inferred by those skilled in the art. Such a computer program may be stored in a computer readable storage medium and read and executed by a computer, thereby implementing embodiments of the present invention. The storage medium of the computer program may include a magnetic recording medium, an optical recording medium, a carrier wave medium, and the like.

In the description of the embodiments, in the case of being described as being formed at "up (up) or down (down)", "before (front) or back (back)" of each component, "up (up) or down (Below) "and" before (before) or after (behind) "include both in which the two components are in direct contact with each other or one or more other components are formed disposed between the two components.

In addition, the terms "comprise", "comprise" or "having" described above mean that the corresponding component may be included, unless otherwise stated, and thus excludes other components. It should be construed that it may further include other components instead. All terms, including technical and scientific terms, have the same meanings as commonly understood by one of ordinary skill in the art unless otherwise defined. Terms commonly used, such as terms defined in a dictionary, should be interpreted to coincide with the contextual meaning of the related art, and shall not be construed in an ideal or excessively formal sense unless explicitly defined in the present invention.

In addition, in describing the component of this invention, terms, such as 1st, 2nd, A, B, (a), (b), can be used. These terms are only for distinguishing the components from other components, and the nature, order or order of the components are not limited by the terms. If a component is described as being "connected", "coupled" or "connected" to another component, that component may be directly connected to or connected to that other component, but there may be another configuration between each component. It is to be understood that the elements may be "connected", "coupled" or "connected".

In the following description of the present invention, when it is determined that the subject matter of the present invention may be unnecessarily obscured by those skilled in the art with respect to the related well-known technology, the detailed description thereof will be omitted.

In the description of the embodiment, the apparatus for transmitting wireless power on the wireless power charging system is a wireless power transmitter, wireless power transmitter, wireless power transmitter, wireless power transmitter, transmitter, transmitter, transmitter, transmitting side for convenience of description. A wireless power transmitter, a wireless power transmitter, and a wireless charging device will be used in combination. In addition, as a representation of a device for receiving the wireless power from the wireless power transmitter, for convenience of description, a wireless power receiver, a wireless power receiver, a wireless power receiver, a wireless power receiver, a receiver terminal, a receiver, a receiver, a receiver Terminals and the like may be used interchangeably.

Wireless charging apparatus according to the present invention may be configured in the form of a pad, a cradle, an access point (AP), a small base station, a stand, a ceiling buried, a wall, etc., one transmitter receives a plurality of wireless power It may also transmit power to the device.

To this end, the wireless power transmitter may provide at least one wireless power transfer scheme, including, for example, an electromagnetic induction scheme, an electromagnetic resonance scheme, and the like.

As another example, the wireless power transmission method may use an electromagnetic resonance method of transmitting power to a wireless power receiver located at a short distance by tuning a magnetic field generated by a transmission coil of the wireless power transmitter to a specific resonance frequency. . For example, the electromagnetic resonant method may include a resonant wireless charging technology defined in an A4WP (Alliance for Wireless Power) standard device, which is a wireless charging technology standard device.

As another example, the wireless power transmission method may use an RF wireless power transmission method that transmits power to a wireless power receiver located at a far distance by putting low power energy on an RF signal.

As another example of the present invention, the wireless power transmitter according to the present invention may be designed to support at least two or more wireless power transmission methods of the electromagnetic induction method, the electromagnetic resonance method, and the RF wireless power transmission method.

In this case, the wireless power transmitter may be adaptively used for the wireless power receiver based on the type, state, power required of the wireless power receiver, as well as the wireless power transmission scheme supported by the wireless power transmitter and the wireless power receiver. Can be determined.

In addition, the wireless power receiver according to an embodiment of the present invention may be provided with at least one wireless power transmission scheme, and may simultaneously receive wireless power from two or more wireless power transmitters. Herein, the wireless power transmission method may include at least one of the electromagnetic induction method, the electromagnetic resonance method, and the RF wireless power transmission method.

The terminal according to the present invention is a mobile phone, smart phone, laptop computer, digital broadcasting terminal, PDA (Personal Digital Assistants), PMP (Portable Multimedia Player), navigation, MP3 player, electric It may be used in small electronic devices such as toothbrushes, electronic tags, lighting devices, remote controls, fishing bobbers, and the like, but is not limited thereto. The term "terminal" or "device" may be used interchangeably. The wireless power receiver according to another embodiment of the present invention may be mounted in a vehicle, an unmanned aerial vehicle, an air drone, or the like.

In general, the wireless power transmitter and the wireless power receiver constituting the wireless power system may exchange control signals or information through in-band communication or Bluetooth low energy (BLE) communication. Here, in-band communication and BLE communication may be performed by a pulse width modulation method, a frequency modulation method, a phase modulation method, an amplitude modulation method, an amplitude and phase modulation method, or the like. For example, the wireless power receiver may transmit various control signals and information to the wireless power transmitter by generating a feedback signal by switching ON / OFF the current induced through the receiving coil in a predetermined pattern. The information transmitted by the wireless power receiver may include various state information including received power strength information. In this case, the wireless power transmitter may calculate the charging efficiency or the power transmission efficiency based on the received power strength information.

In one embodiment of the present invention, the wireless communication between the wireless power transmission control device and a terminal (device) including the wireless power receiver is a wireless communication channel for controlling power transmission between the wireless power transmitter and the wireless power receiver. A separate communication channel, different from the in-band (BLE) communication channel, may be used. As another example, when the wireless communication channel for controlling power transmission between the wireless power transmitter and the wireless power receiver is an out-of-band communication channel such as BLE (Bluetooth Low Energy) communication, the wireless power transmission control device may be a wireless power receiver. The communication channel for identifying whether the power transmitter should be activated to be a receiver may be a communication channel different from the out-of-band communication channel.

Hereinafter, the electromagnetic resonance method of the wireless power transmission method will be described with reference to FIGS. 1 to 6, and the pairing method of the wireless power transceiver using the Bluetooth communication method (Bluetooth Low Energy, BLE) in FIG. 7 will be described. The NFC communication method will be described with reference to FIG. 8. Hereinafter, a method of mutually searching and recognizing wireless power transceivers using the NFC communication scheme will be described with reference to FIGS. 9 to 11.

Referring to FIG. 1, the wireless power transmission system may include a wireless power transmitter 100 and a wireless power receiver 200.

Although FIG. 1 illustrates that the wireless power transmitter 100 transmits wireless power to one wireless power receiver 200, this is only one embodiment, and wireless power according to another embodiment of the present invention. The transmitter 100 may transmit wireless power to the plurality of wireless power receivers 200. It should be noted that the wireless power receiver 200 according to another embodiment may simultaneously receive wireless power from the plurality of wireless power transmitters 100.

The wireless power transmitter 100 may generate a magnetic field using a specific power transmission frequency to transmit power to the wireless power receiver 200.

The wireless power receiver 200 may receive power by tuning to the same frequency as that used by the wireless power transmitter 100.

For example, the frequency for power transmission may be a 6.78MHz band, but is not limited thereto.

That is, the power transmitted by the wireless power transmitter 100 may be transmitted to the wireless power receiver 200 which is in resonance with the wireless power transmitter 100.

The maximum number of wireless power receivers 200 that can receive power from one wireless power transmitter 100 is the maximum transmit power level of the wireless power transmitter 100, the maximum power reception level of the wireless power receiver 200, the wireless It may be determined based on the physical structures of the power transmitter 100 and the wireless power receiver 200.

The wireless power transmitter 100 and the wireless power receiver 200 may perform bidirectional communication in a frequency band different from a frequency band for transmitting wireless power, that is, a resonant frequency band. For example, at least one of a half-duplex Bluetooth Low Energy (BLE) communication protocol and Near Field Communication (NFC) may be used for bidirectional communication.

The wireless power transmitter 100 and the wireless power receiver 200 may exchange characteristic and state information, that is, power negotiation information, with each other through the bidirectional communication.

For example, the wireless power receiver 200 may transmit predetermined power reception state information for controlling the power level received from the wireless power transmitter 100 to the wireless power transmitter 100 through bidirectional communication. 100 may dynamically control the transmit power level based on the received power reception state information. Through this, the wireless power transmitter 100 may not only optimize power transmission efficiency, but also prevent load damage due to over-voltage, and prevent unnecessary waste of power due to under-voltage. It can provide a function to.

In addition, the wireless power transmitter 100 performs a function of authenticating and identifying the wireless power receiver 200 through two-way communication, identifying an incompatible device or an unchargeable object, and identifying a valid load. You may.

Hereinafter, the wireless power transmission process of the resonance method will be described in detail with reference to FIG. 1.

The wireless power transmitter 100 includes a power supplier 110, a power conversion unit 120, a matching circuit 130, a transmission resonator 140, and a main controller. , 150) and a communication unit 160. The communicator 160 may include a data transmitter and a data receiver.

The power supply unit 110 may supply a specific supply voltage to the power converter 120 under the control of the main controller 150. In this case, the supply voltage may be a DC voltage or an AC voltage.

The power converter 210 may convert the voltage received from the power supply unit 110 into a specific voltage under the control of the main controller 150. To this end, the power converter 210 may include at least one of a DC / DC converter, an AC / DC converter, and a power amplifier.

The matching circuit 130 is a circuit that matches the impedance between the power converter 210 and the transmission resonator 140 to maximize power transmission efficiency.

The transmission resonator 140 may wirelessly transmit power using a specific resonance frequency according to the voltage applied from the matching circuit 130.

The communication unit 160 may perform out-of-band communication with the communication unit 260 of the wireless power receiver as bidirectional half-duplex communication. In one embodiment, the communication unit 160 may include a Bluetooth low energy (BLE) module or a near field communication (NFC) module according to a communication method.

The wireless power receiver 200 includes a reception resonator 210, a rectifier 220, a DC-DC converter 230, a load 240, a main controller 250. ) And a communication unit 260. The communication unit 260 may include a data transmitter and a data receiver.

The reception resonator 210 may receive power transmitted by the transmission resonator 140 through a resonance phenomenon.

The rectifier 210 may perform a function of converting an AC voltage applied from the receiving resonator 210 into a DC voltage.

The DC-DC converter 230 may convert the rectified DC voltage into a specific DC voltage required for the load 240.

The main controller 250 controls the operations of the rectifier 220 and the DC-DC converter 230 or generates characteristics and state information of the wireless power receiver 200 and controls the communication unit 260 to control the wireless power transmitter 100. The characteristics and state information of the wireless power receiver 200 may be transmitted to the. For example, the main controller 250 may control the operation of the rectifier 220 and the DC-DC converter 230 by monitoring the intensity of the output voltage and the current in the rectifier 220 and the DC-DC converter 230. have.

The intensity information of the monitored output voltage and current may be transmitted to the wireless power transmitter 100 in real time through the communication unit 260.

In addition, the main controller 250 compares the rectified DC voltage with a predetermined reference voltage to determine whether it is an over-voltage state or an under-voltage state, and a system error state is detected according to the determination result. If so, the detection result may be transmitted to the wireless power transmitter 100 through the communication unit 260.

In addition, when the main controller 250 detects a system error condition, the main controller 250 controls the operation of the rectifier 220 and the DC-DC converter 230 or a predetermined overcurrent including a switch or a zener diode to prevent damage to the load. The blocking circuit may be used to control the power applied to the load 240.

The communication unit 260 may perform out-of-band communication with the communication unit 160 of the wireless power transmitter, and may include a Bluetooth low energy (BLE) module or a near field communication (NFC) module according to a communication method. can do.

In FIG. 1, the

main controller

150 and 250 and the

communication unit

160 and 260 are configured as different modules, but this is only one embodiment, and another embodiment of the present invention is a main controller ( It should be noted that the 150 and 250 and the

communication unit

160 and 260 may be configured as one module.

In detail, FIG. 2 shows the interface point on an equivalent circuit in which reference parameters, which will be described later, are measured.

Hereinafter, the meanings of the reference parameters shown in FIG. 2 will be briefly described.

I _TX and I _TX _{_COIL} are root mean square (RMS) currents applied to the matching circuit (or matching network) 201 of the wireless power transmitter and RMS currents applied to the transmission resonator coil 202 of the wireless power transmitter, respectively. do.

Z _TX _{_IN} and Z _TX _{_IN_COIL} mean an input impedance before the matching circuit 201 of the wireless power transmitter, an input impedance after the matching circuit 201 and a front end of the transmission resonator coil 202, respectively.

L1 and L2 mean an inductance value of the transmitting resonator coil 202 and an inductance value of the receiving resonator coil 203, respectively.

Z _RX _{_ IN} refers to the input impedance at the rear end of the matching circuit 204 and the front end of the filter / rectifier / load 205 of the wireless power receiver.

The resonance frequency used for the operation of the wireless power transmission system according to an embodiment of the present invention may be 6.78MHz ± 15kHz.

In addition, the wireless power transmission system according to an embodiment may provide simultaneous charging of multiple wireless power receivers, i.e., multi-charging, in which case the wireless power receiver remains even if the wireless power receiver is newly added or deleted. The amount of change in received power may be controlled so as not to exceed a predetermined reference value. For example, the received power variation may be ± 10%, but is not limited thereto.

The condition for maintaining the received power change amount should not overlap with the existing wireless power receiver when the wireless power receiver is added to or deleted from the charging area.

When the matching circuit 204 of the wireless power receiver is connected to the rectifier, the real part of the Z _{TX —} _IN may be inversely related to the load resistance of the rectifier, hereinafter referred to as R _RECT . That is, increasing R _RECT may decrease Z _TX _{_IN,} and decreasing R _RECT may increase Z _TX _{_IN} .

Resonator Coupling Efficiency according to the present invention may be the maximum power reception ratio calculated by dividing the power transferred from the receiver resonator coil to the load 204 by the power carried in the resonant frequency band by the transmitter resonator coil 202. have. Resonator matching efficiency between the wireless power transmitter and wireless power receiver can be calculated if the reference port impedance (Z _{TX_IN)} and receiving a reference port impedance (Z _{_IN} _RX) of the cavity resonator is a transmission that is perfectly matched.

Table 1 below is an example of the minimum resonator matching efficiency according to the class of the wireless power transmitter and the class of the wireless power receiver according to the embodiment of the present invention.

	카테고리 1Category 1	카테고리 2Category 2	카테고리 3Category 3	카테고리 4Category 4	카테고리 5Category 5	카테고리 6Category 6	카테고리 7Category 7
등급 1Grade 1	N/AN / A	N/AN / A	N/AN / A	N/AN / A	N/AN / A	N/AN / A	N/AN / A
등급 2Grade 2	N/AN / A	74%(-1.3)74% (-1.3)	74%(-1.3)74% (-1.3)	N/AN / A	N/AN / A	N/AN / A	N/AN / A
등급 3Grade 3	N/AN / A	74%(-1.3)74% (-1.3)	74%(-1.3)74% (-1.3)	76%(-1.2)76% (-1.2)	N/AN / A	N/AN / A	N/AN / A
등급 4Grade 4	N/AN / A	50%(-3)50% (-3)	65%(-1.9)65% (-1.9)	73%(-1.4)73% (-1.4)	76%(-1.2)76% (-1.2)	N/AN / A	N/AN / A
등급 5Grade 5	N/AN / A	40%(-4)40% (-4)	60%(-2.2)60% (-2.2)	63%(-2)63% (-2)	73%(-1.4)73% (-1.4)	76%(-1.2)76% (-1.2)	N/AN / A
등급 6Grade 6	N/AN / A	30%(-5.2)30% (-5.2)	50%(-3)50% (-3)	54%(-2.7)54% (-2.7)	63%(-2)63% (-2)	73%(-1.4)73% (-1.4)	76%(-1.2)76% (-1.2)

If a plurality of wireless power receivers are used, the minimum resonator matching efficiency corresponding to the class and category shown in Table 1 may increase.

3 is a state transition diagram for explaining a state transition procedure in the wireless power transmitter of the electromagnetic resonance method according to an embodiment of the present invention.

Referring to FIG. 3, the state of the wireless power transmitter is largely configured in a configuration state 310, a power save state 320, a low power state 330, and a power transfer state. , 340), a local fault state 350, and a locking fault state 360.

When power is applied to the wireless power transmitter, the wireless power transmitter may transition to configuration state 310. The wireless power transmitter may transition to the power saving state 320 when the predetermined reset timer expires or the initialization procedure is completed in the configuration state 310.

In the power saving state 320, the wireless power transmitter may generate a beacon sequence and transmit it through the resonant frequency band.

Here, the wireless power transmitter may control the beacon sequence to be started within a predetermined time after entering the power saving state 320. For example, the wireless power transmitter may control the beacon sequence to be started within 50 ms after the power saving state 320 transition, but is not limited thereto.

In the power saving state 320, the wireless power transmitter periodically generates and transmits a first beacon sequence for sensing the wireless power receiver, and detects a change in impedance of the reception resonator, that is, a load variation. Can be. Hereinafter, for convenience of description, the first beacon and the first beacon sequence will be referred to as short beacon and short beacon sequences, respectively.

In particular, the short beacon sequence may be repeatedly generated and transmitted at a predetermined time interval t _CYCLE for a short period (t _SHORT _{_ BEACON} ) to save standby power of the wireless power transmitter until the wireless power receiver is detected. For example, t _SHORT _{_BEACON} may be set to 30 ms or less and t _CYCLE to 250 ms ± 5 ms. In addition, the current strength of the short beacon is more than a predetermined reference value, and may increase gradually over a period of time. As an example, the minimum current strength of the short beacon may be set sufficiently large so that the wireless power receiver of category 2 or higher of Table 2 may be detected.

The wireless power transmitter according to the present invention may be provided with a predetermined sensing means for detecting a change in reactance and resistance in a reception resonator according to a short beacon.

In addition, in the power saving state 320, the wireless power transmitter may periodically generate and transmit a second beacon sequence for supplying sufficient power for booting and response of the wireless power receiver. Hereinafter, for convenience of description, the second beacon and the second beacon sequence will be referred to as long beacon and long beacon sequences, respectively.

That is, when booting is completed through the second beacon sequence, the wireless power receiver may broadcast a predetermined response signal through the out-of-band communication channel.

In particular, the Long Beacon sequence may be generated and transmitted at a predetermined time interval (t _LONG _{_BEACON_PERIOD} ) during a relatively long period (t _{LONG_BEACON} ) compared to the Short Beacon to supply sufficient power for booting the wireless power receiver. For example, t _LONG _{_BEACON} may be set to 105 ms + 5 ms and t _LONG _{_BEACON_PERIOD} may be set to ₈₅₀ ms, respectively. The current strength of the long beacon may be relatively strong compared to the current strength of the short beacon. In addition, the Long Beacon may maintain a constant power during the transmission interval.

Thereafter, after the wireless power transmitter detects a change in the impedance of the reception resonator, the wireless power transmitter may wait to receive a predetermined response signal during the long beacon transmission period. Hereinafter, for convenience of description, the response signal will be referred to as an advertisement signal. Here, the wireless power receiver may broadcast the advertisement signal through an out-of-band communication frequency band different from the resonant frequency band.

For example, the advertisement signal may include message identification information for identifying a message defined in the corresponding out-of-band communication standard, unique service for identifying whether the wireless power receiver is a legitimate or compatible receiver for the wireless power transmitter, or wireless power receiver identification. Information, output power information of the wireless power receiver, rated voltage / current information applied to the load, antenna gain information of the wireless power receiver, information for identifying the category of the wireless power receiver, wireless power receiver authentication information, with overvoltage protection Information on whether or not, may include at least one or any one of the software version information mounted on the wireless power receiver.

When the advertisement signal is received, the wireless power transmitter may transition from the power saving state 320 to the low power state 330 and then establish an out-of-band communication link with the wireless power receiver. Subsequently, the wireless power transmitter may perform a registration procedure for the wireless power receiver via the established out-of-band communication link. For example, when the out-of-band communication is Bluetooth low power communication, the wireless power transmitter may perform Bluetooth pairing with the wireless power receiver and exchange at least one of state information, characteristic information, and control information with each other through the paired Bluetooth link. have.

When the wireless power transmitter transmits a predetermined control signal to the wireless power receiver for initiating charging through out-of-band communication in the low power state 330, that is, the predetermined predetermined control signal requesting that the wireless power receiver delivers power to the load. The state of the wireless power transmitter may transition from the low power state 330 to the power transfer state 340.

If the out-of-band communication link establishment procedure or registration procedure is not normally completed in the low power state 330, the state of the wireless power transmitter may transition to the power saving state 320 in the low power state 330.

The wireless power transmitter may be driven by a separate Link Expiration Timer for connection with each wireless power receiver, and the wireless power receiver may indicate that the wireless power transmitter is present in the wireless power transmitter at a predetermined time period. Must be sent before the link expiration timer expires. The link expiration timer is reset each time the message is received and an out-of-band communication link established between the wireless power receiver and the wireless power receiver may be maintained if the link expiration timer has not expired.

If, in the low power state 330 or the power transfer state 340, all link expiration timers corresponding to the out-of-band communication link established between the wireless power transmitter and the at least one wireless power receiver have expired, the state of the wireless power transmitter May transition to a power saving state 320.

Also, the wireless power transmitter in the low power state 330 may drive a predetermined registration timer when a valid advertisement signal is received from the wireless power receiver. In this case, when the registration timer expires, the wireless power transmitter in the low power state 330 may transition to the power saving state 320. In this case, the wireless power transmitter may output a predetermined notification signal indicating that registration has failed through notification display means provided in the wireless power transmitter, including, for example, an LED lamp, a display screen, a beeper, and the like. have.

In addition, in the power transmission state 340, the wireless power transmitter may transition to the low power state 330 when charging of all connected wireless power receivers is completed.

In particular, the wireless power receiver may allow registration of a new wireless power receiver in states other than configuration state 310, local failure state 350, and lock failure state 360.

In addition, the wireless power transmitter may dynamically control the transmission power based on state information received from the wireless power receiver in the power transmission state 340.

At this time, the receiver state information transmitted from the wireless power receiver to the wireless power transmitter is for reporting the required power information, voltage and / or current information measured at the rear of the rectifier, charging state information, overcurrent and / or overvoltage and / or overheating state. It may include at least one of information indicating whether the means for interrupting or reducing the power delivered to the load according to the information, overcurrent or overvoltage is activated. In this case, the receiver state information may be transmitted at a predetermined cycle or whenever a specific event occurs. In addition, the means for cutting off or reducing power delivered to the load according to the overcurrent or overvoltage may be provided using at least one of an ON / OFF switch and a zener diode.

Receiver state information transmitted from a wireless power receiver to a wireless power transmitter according to another embodiment of the present invention is information indicating that an external power source is wired to the wireless power receiver, information indicating that an out-of-band communication scheme has been changed. It may further include at least one of-can be changed from NFC (Near Field Communication) to Bluetooth Low Energy (BLE) communication.

According to another embodiment of the present invention, a wireless power transmitter may receive power for each wireless power receiver based on at least one of its currently available power, priority for each wireless power receiver, and the number of connected wireless power receivers. May be adaptively determined. Here, the power strength for each wireless power receiver may be determined by a ratio of power to the maximum power that can be processed by the rectifier of the wireless power receiver.

Thereafter, the wireless power transmitter may transmit a predetermined power control command including information about the determined power intensity to the corresponding wireless power receiver. In this case, the wireless power receiver may determine whether power control is possible using the power intensity determined by the wireless power transmitter, and transmit the determination result to the wireless power transmitter through a predetermined power control response message.

The wireless power receiver according to another embodiment of the present invention may transmit predetermined receiver state information indicating whether wireless power control is possible according to the power control command of the wireless power transmitter before receiving the power control command.

The power transmission state 340 may be any one of a first state 341, a second state 342, and a third state 343 according to the power reception state of the connected wireless power receiver.

For example, the first state 341 may mean that power reception states of all wireless power receivers connected to the wireless power transmitter are normal voltages.

The second state 342 may mean that there is no wireless power receiver in which the power reception state of the at least one wireless power receiver connected to the wireless power transmitter is a low voltage state and a high voltage state.

The third state 343 may mean that a power reception state of at least one wireless power receiver connected to the wireless power transmitter is a high voltage state.

The wireless power transmitter may transition to the lock failure state 360 when a system error is detected in the power saving state 320, the low power state 330, or the power transmission state 340.

The wireless power transmitter in the lock failure state 360 may transition to the configuration state 310 or the power saving state 320 when it is determined that all connected wireless power receivers have been removed from the charging area.

In addition, in the lock failure state 360, the wireless power transmitter may transition to the local failure state 350 when a local failure is detected. Herein, when the local failure is released, the wireless power transmitter having the local failure state 350 may transition to the lock failure state 360 again.

On the other hand, when the transition to the local failure state 350 in any one of the configuration state 310, the power saving state 320, the low power state 330, the power transmission state 340, the wireless power transmitter has a local failure Once released, transition to configuration state 310 may occur.

When the wireless power transmitter transitions to the local failure state 350, the wireless power transmitter may cut off the power supplied to the wireless power transmitter. For example, the wireless power transmitter may transition to the local failure state 350 when the failure of overvoltage, overcurrent, overheating, etc. is detected, but is not limited thereto.

For example, when an overcurrent, an overvoltage, an overheat, or the like is detected, the wireless power transmitter may transmit a predetermined power control command to at least one connected wireless power receiver to reduce the strength of the power received by the wireless power receiver.

As another example, when an overcurrent, an overvoltage, an overheat, or the like is detected, the wireless power transmitter may transmit a predetermined control command to the connected at least one wireless power receiver to stop charging of the wireless power receiver.

Through the above power control procedure, the wireless power transmitter can prevent device damage due to overvoltage, overcurrent, overheating, and the like.

The wireless power transmitter may transition to the lock failure state 360 when the intensity of the output current of the transmission resonator is greater than or equal to the reference value. At this time, the wireless power transmitter transitioned to the lock failure state 360 may attempt to make the intensity of the output current of the transmission resonator less than or equal to the reference value for a predetermined time. Here, the attempt may be repeated for a predetermined number of times. If the lock failure state 360 is not released despite the repetition, the wireless power transmitter transmits a predetermined notification signal indicating that the lock failure state 360 is not released to the user by using a predetermined notification means. can do. In this case, when all the wireless power receivers located in the charging area of the wireless power transmitter are removed from the charging area by the user, the lock failure state 360 may be released.

On the other hand, when the intensity of the output current of the transmission resonator falls below the reference value within a predetermined time or during the predetermined repetition, the lock failure state 360 is automatically released. In this case, the state of the wireless power transmitter may automatically transition from the lock failure state 360 to the power saving state 320 to perform the detection and identification procedure for the wireless power receiver again.

The wireless power transmitter of the power transmission state 340 transmits continuous power, and adaptively controls the output power based on the state information of the wireless power receiver and a predefined optimal voltage region setting parameter. have.

For example, the optimal voltage region setting parameter may include at least one of a parameter for identifying a low voltage region, a parameter for identifying an optimal voltage region, a parameter for identifying a high voltage region, and a parameter for identifying an overvoltage region. It may include.

The wireless power transmitter may increase the output power if the power reception state of the wireless power receiver is in the low voltage region, and reduce the output power if the wireless power receiver is in the high voltage region.

In addition, the wireless power transmitter may control the transmission power to maximize the power transmission efficiency.

In addition, the wireless power transmitter may control the transmission power so that the deviation of the amount of power required by the wireless power receiver is equal to or less than the reference value.

In addition, the wireless power transmitter may stop power transmission when the rectifier output voltage of the wireless power receiver reaches a predetermined overvoltage region, that is, when an over voltage is detected.

Referring to FIG. 4, a state of a wireless power receiver may be classified into a disable state (410), a boot state (420), an enable state (430) (or an on state), and a system error state ( System Error State, 440) can be configured.

In this case, the state of the wireless power receiver may be determined based on the intensity of the output voltage at the rectifier terminal of the wireless power receiver, hereinafter, referred to as a V _RECT business card.

The activation state 430 may be classified into an optimal voltage state 431, a low voltage state 432, and a high voltage state 433 according to the value of V _RECT .

The wireless power receiver in the deactivated state 410 may transition to the boot state 420 if the measured V _RECT value is greater than or equal to a predefined V _{RECT_BOOT} value.

In boot state 420, the wireless power receiver establishes an out-of-band communication link with the wireless power transmitter and V _RECT Wait until the value reaches the power required by the load stage.

Wireless power receiver in boot state 420 is V _RECT When it is confirmed that the value has reached the power required for the load stage, the transition to the active state 430 may begin charging.

The wireless power receiver in the activated state 430 may transition to the boot state 420 when charging is confirmed to be completed or stopped.

In addition, the wireless power receiver in the activated state 430 may transition to the system error state 440 when a predetermined system error is detected. Here, the system error may include overvoltage, overcurrent and overheating as well as other predefined system error conditions.

In addition, the wireless power receiver in the active state 430 is V _RECT If the value falls below the V _RECT _{_BOOT} value, it may transition to an inactive state 410.

The wireless power receiver of the boot state 420 or system failure condition 440 may be shifted to, disable state (410) falls below a value V _RECT V _RECT _{_BOOT} value.

Hereinafter, the state transition of the wireless power receiver in the activated state 430 will be described in detail with reference to FIG. 5 to be described later.

Referring to FIG. 5, if the V _RECT value is smaller than a predetermined V _RECT _{_} _BOOT , the wireless power receiver is maintained in an inactive state 410.

Thereafter, if the V _RECT value is increased above V _RECT _{_BOOT} , the wireless power receiver transitions to the boot state 420 and may broadcast the advertisement signal within a predetermined time. Thereafter, when the advertisement signal is detected by the wireless power transmitter, the wireless power transmitter may transmit a predetermined connection request signal for establishing an out-of-band communication link to the wireless power receiver.

The wireless power receiver is normally set to communicate the out-of-band link, if a successful registration, V _RECT value of the minimum output voltage of the rectifier for a normal charge-to below, for convenience of explanation V _RECT _{_} _MIN as business card is reached You can wait until

If the V _RECT value exceeds V _RECT _{_ MIN} , the state of the wireless power receiver transitions from the boot state 420 to the activated state 430 and may begin charging the load.

If the V _RECT value in the activation state 430 exceeds V _RECT _{_ MAX} , which is a predetermined reference value for determining the overvoltage, the wireless power receiver may transition from the activation state 430 to the system error state 440.

Referring to FIG. 5, the activation state 530 is divided into a low voltage state 532, an optimum voltage state 531, and a high voltage state 533 according to the value of V _RECT . Can be.

The low voltage state 532 means a state where V _RECT _{_BOOT} <= V _RECT <= V _RECT _{_} _MIN , and the optimum voltage state 531 means a state where V _RECT _{_MIN} <V _RECT <= V _RECT _{_} _HIGH , The high voltage state 533 may refer to a state in which V _{RECT_HIGH} <V _RECT <= V _RECT _{_} _MAX .

In particular, the wireless power receiver transitioned to the high voltage state 533 may suspend the operation of cutting off the power supplied to the load for a predetermined time, which is referred to as a high voltage state holding time for convenience of description below. In this case, the high voltage state holding time may be determined in advance so that no damage occurs to the wireless power receiver and the load in the high voltage state 533.

When the wireless power receiver transitions to the system error state 540, the wireless power receiver may transmit a predetermined message indicating overvoltage occurrence to the wireless power transmitter through the out-of-band communication link within a predetermined time.

In addition, the wireless power receiver may control the voltage applied to the load by using an overvoltage blocking means provided to prevent damage of the load due to the overvoltage in the system error state 530. Here, an ON / OFF switch or a zener diode may be used as the overvoltage blocking means.

In the above embodiment, when an overvoltage occurs in the wireless power receiver and transitions to the system error state 540, the method and means for responding to a system error in the wireless power receiver are described. However, this is only one embodiment. Another embodiment may transition to a system error state by overheating, overcurrent, or the like in the wireless power receiver.

For example, when a transition to a system error state occurs due to overheating, the wireless power receiver may transmit a predetermined message indicating the occurrence of overheating to the wireless power transmitter. In this case, the wireless power receiver may reduce the heat generated internally by driving the provided cooling fan.

The wireless power receiver according to another embodiment of the present invention may receive wireless power in cooperation with a plurality of wireless power transmitters. In this case, the wireless power receiver may transition to the system error state 540 when it is determined that the wireless power transmitter determined to receive the actual wireless power is different from the wireless power transmitter to which the actual out-of-band communication link is established.

Hereinafter, a signaling procedure between a wireless power transmitter and a wireless power receiver according to the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 6, when the wireless power transmitter is configured to receive power, that is, booting is completed, the wireless power transmitter may generate a beacon sequence and transmit it through a transmission resonator (S601).

When the beacon sequence is detected, the wireless power receiver may broadcast an advertisement signal including its identification information and characteristic information (S603). In this case, it should be noted that the advertisement signal may be repeatedly transmitted at a predetermined period until the connection request signal, which will be described later, is received from the wireless power transmitter.

When the advertisement signal is received, the wireless power transmitter may transmit a predetermined connection request signal for establishing an out-of-band communication link to the wireless power receiver (S605).

When the wireless power receiver receives the connection request signal, the wireless power receiver may establish an out-of-band communication link and transmit its static state information through the set out-of-band communication link (S607).

In this case, the static state information of the wireless power receiver identifies category information, hardware and software version information, maximum rectifier output power information, initial reference parameter information for power control, information on a required voltage or power, and whether a power regulation function is installed. And at least one of information on supportable out-of-band communication schemes, information on supportable power control algorithms, and information on preferred rectifier stage voltage values initially set in the wireless power receiver.

When the static state information of the wireless power receiver is received, the wireless power transmitter may transmit the static state information of the wireless power transmitter to the wireless power receiver through an out-of-band communication link (S609).

Here, the static state information of the wireless power transmitter may include at least one of transmitter power information, class information, hardware and software version information, information on the maximum number of supported wireless power receivers, and / or information on the number of wireless power receivers currently connected. It can be configured to include one.

Thereafter, the wireless power receiver monitors its real-time power reception state and charging state, and may transmit dynamic state information to the wireless power transmitter in a periodic or specific event occurrence (S611).

Here, the dynamic state information of the wireless power receiver includes information on the rectifier output voltage and current, information on the voltage and current applied to the load, information on the internal measurement temperature of the wireless power receiver, and change of reference parameters for power control ( It may be configured to include at least one of the rectified voltage minimum value, the rectified voltage maximum value, the initially set preferred rectifier terminal voltage change value), the charging state information, system error information, alarm information. The wireless power transmitter may perform power adjustment by changing a setting value included in the existing static state information when receiving reference parameter change information for power control.

In addition, when sufficient power for charging the wireless power receiver is prepared, the wireless power transmitter may control the wireless power receiver to start charging by issuing a predetermined control command through the out-of-band communication link (S613).

Thereafter, the wireless power transmitter may dynamically control the transmission power by receiving the dynamic state information from the wireless power receiver (S615).

In addition, when an internal system error is detected or the charging is completed, the wireless power receiver may transmit the dynamic state information to the wireless power transmitter including data for identifying the system error and / or data indicating that the charging is completed ( S617). Here, the system error may include overcurrent, overvoltage, overheating, and the like.

In addition, when the currently available power does not meet the required power of all connected wireless power receivers, the wireless power transmitter according to another embodiment of the present invention redistributes power to be transmitted to each wireless power receiver and issues a predetermined control command. It may be transmitted to the corresponding wireless power receiver.

In addition, when a new wireless power receiver is registered during wireless charging, the wireless power transmitter redistributes power to be received for each connected wireless power receiver based on currently available power, and transmits it to the corresponding wireless power receiver through a predetermined control command. It may be.

In addition, the wireless power transmitter may remain when wireless charging of the previously connected wireless power receiver is completed or the out-of-band communication link is released, including, for example, when the wireless power receiver is removed from the charging area. The power to be received for each wireless power receiver may be redistributed and transmitted to the corresponding wireless power receiver through a predetermined control command.

In addition, the wireless power transmitter may determine whether the wireless power receiver has a power regulation function through a predetermined control procedure. In this case, when a power redistribution situation occurs, the wireless power transmitter may perform power redistribution only for the wireless power receiver equipped with the power adjustment function.

For example, the power redistribution situation may receive a valid advertisement signal from an unconnected wireless power receiver to receive a dynamic parameter indicating a new wireless power receiver is added or indicates a current state of the connected wireless power receiver, or the connected wireless power receiver is Occurs when an event occurs such that it is confirmed that it no longer exists, the charging of the connected wireless power receiver is completed, or an alert message indicating a system error state of the connected wireless power receiver is received. have.

Here, the system error state may include an overvoltage state, an overcurrent state, an overheat state, a network connection state, and the like.

For example, the wireless power transmitter may transmit power redistribution related information to the wireless power receiver through a predetermined control command.

Here, the power redistribution related information is a wireless power transmitter command for power control,

For example, when a new wireless power receiver is registered, the wireless power transmitter may determine whether it is possible to provide the amount of power required by the wireless power receiver based on its available power. As a result of determination, when the required amount of power exceeds the available amount of power, the wireless power transmitter may check whether the power control function is installed in the corresponding wireless power receiver. As a result of the check, when the power adjustment function is mounted, the wireless power receiver may determine an amount of power to be received by the wireless power receiver within the amount of available power, and transmit the determined result to the wireless power receiver through a predetermined control command.

Of course, the power redistribution may be performed within a range in which the wireless power transmitter and the wireless power receiver can operate normally and / or a normal charging range.

The wireless power receiver according to another embodiment of the present invention may support a plurality of out-of-band communication schemes. If it is desired to change the currently set out-of-band communication link in another manner, the wireless power receiver may transmit a predetermined control signal for requesting the out-of-band communication change to the wireless power transmitter. When the out-of-band communication change request signal is received, the wireless power transmitter may release the currently set out-of-band communication link and establish a new out-of-band communication link by the out-of-band communication method requested by the wireless power receiver.

For example, the out-of-band communication scheme applicable to the present invention may include Near Field Communication (NFC), Radio Frequency Identification (RFID), Bluetooth Low Energy (BLE), Wideband Code Division Multiple Access (WCDMA), and Long LTE. Term Evolution) / LTE-Advance communication and Wi-Fi communication.

7 is a flowchart illustrating operations of a wireless power transmitter and a wireless power receiver according to a Bluetooth communication method according to an embodiment of the present invention.

Referring to FIG. 7, when power is applied to the wireless power transmitter 700 (S701), the wireless power transmitter 700 may enter a configuration state (S702).

Thereafter, the wireless power transmitter 700 may enter a power save state in a configuration state (S703).

In the power saving state, the wireless power transmitter 700 may apply different types of detection power beacons at respective cycles. Beacon is a signal with Bluetooth Low Energy ("BLE") technology, Bluetooth 4.0 version. For example, the wireless power transmitter 700 may apply a detection power beacon (eg, a short beacon or a long beacon) (S704 and S705), and detect power. The magnitude of the power value of each of the beacons may be different.

Some or all of the detection power beacons may have a power amount capable of driving the communication unit of the wireless power receiver 750. For example, the wireless power receiver 750 may drive the communication unit by some or all of the detection power beacons to communicate with the wireless power transmitter 700. In this case, the state may be referred to as a null state (disable state) state (S706).

The wireless power transmitter 700 may detect a load change due to the arrangement of the wireless power receiver 750, and may enter a low power state after detecting the load change (S708).

Meanwhile, the wireless power receiver 750 may drive the communication unit based on the power received from the wireless power transmitter 700 (S709). The wireless power receiver 750 may transmit a PTU searching signal to the wireless power transmitter 700 (S710).

The wireless power receiver 750 may transmit a BLE based advertising signal (AD) as a signal for searching for a wireless power transmitter. The wireless power receiver 750 may periodically transmit a wireless power transmitter search signal, and may receive a response signal from the wireless power transmitter 700 or until a preset time arrives.

In addition, according to an embodiment of the present disclosure, the wireless power receiver 750 detects identification information of the wireless power transmitter 700 included in the beacon signal transmitted from the wireless power transmitter 700, and detects the detected identification. Information may be included in the advertising signal and transmitted.

When the wireless power transmitter search signal is received from the wireless power receiver 750, the wireless power transmitter 700 may transmit a PRU response signal (S711). Here, the response signal may form a connection between the wireless power transmitter 700 and the wireless power receiver 750.

After the connection between the wireless power transmitter 700 and the wireless power receiver 750 is formed, the wireless power receiver 750 may transmit a PRU static signal (S712). Here, the PRU static signal may be a signal indicating the state of the wireless power receiver 750, and may request to join the wireless power network controlled by the wireless power transmitter 400.

The wireless power transmitter 700 may transmit a PTU static signal (S713). The PTU static signal transmitted by the wireless power transmitter 700 may be a signal indicating the capability of the wireless power transmitter 700.

When the wireless power transmitter 700 and the wireless power receiver 750 transmit and receive the PRU static signal and the PTU static signal, the wireless power receiver 750 may periodically transmit the PRU dynamic signal (S714 and S715). .

The PRU dynamic signal may include at least one parameter information measured by the wireless power receiver 750. For example, the PRU dynamic signal may include voltage information behind the rectifier of the wireless power receiver 750. The state of the wireless power receiver 750 may be referred to as a boot state S707.

The wireless power transmitter 700 enters a power transfer state (S716), and the wireless power transmitter 700 is a PRU control which is a command signal for allowing the wireless power receiver 750 to perform charging. The signal may be transmitted (S717). In the power transmission state, the wireless power transmitter 700 may transmit charging power.

The PRU control signal transmitted by the wireless power transmitter 700 may include information for enabling / disabling the charging of the wireless power receiver 750 and permission information. The PRU control signal may be sent whenever the state of charge changes. The PRU control signal may be transmitted every 250 ms, for example, or may be transmitted when there is a parameter change. The PRU control signal may be set to be transmitted within a preset threshold time, for example 1 second, even if the parameter does not change.

The wireless power receiver 750 may change a setting according to a PRU control signal, and transmit a wireless power receiver dynamic (PRU dynamic) signal for reporting the status of the wireless power receiver 750 (S718, S719). ).

The PRU dynamic signal transmitted by the wireless power receiver 750 may include at least one of voltage, current, state, and temperature information of the wireless power receiver 750. The state of the wireless power receiver 750 may be referred to as an on state (S720). The PRU dynamic signal may have a data structure as shown in Table 2 below.

필드(field)Field	옥텟(octet)Octet	설명Explanation	사용use	단위unit
선택 필드 타당(Optional field validity)Optional field validity	1One	선택 필드가 채워져있는지 여부Whether the selection field is populated	강제compulsion
VrectVrect	22	정류부의 후단(출력단)에서 DC 전압DC voltage at rear of rectifier (output)	강제compulsion	mVmV
IrectIrect	22	정류부의 후단(출력단)에서 DC 전류DC current at rear of rectifier (output)	강제compulsion	mAmA
VoutVout	22	충전단자(배터리단자)에서 전압 Voltage at the charging terminal (battery terminal)	임의option	mVmV
IoutIout	22	충전단자(배터리단자)에서 전류Current at the charging terminal (battery terminal)	임의option	mAmA
TratioTratio	1One	과온도(TOP) 대비 현재 온도Current temperature over TOP	임의option	Bit fieldBit field
Vrect_min_dynVrect_min_dyn	22	무선 전력 수신기 정류부의 후단 최소 전압 정보Minimum voltage information behind the rectifier of the wireless power receiver	임의option	mVmV
Vrect_set_dynVrect_set_dyn	22	무선 전력 수신기 정류부의 후단 최적 전압값 정보Optimal Voltage Value of Back Stage of Wireless Power Receiver Rectifier	임의option	mVmV
Vrect_high_dynVrect_high_dyn	22	무선 전력 수신기의 정류부 후단 최대 전압값 정보Maximum voltage value at the rear of rectifier of wireless power receiver	임의option	mVmV
PRU alertPRU alert	1One	경고 정보Alert Information	강제compulsion	Bit fieldBit field
Tester commandTester command	1One	테스트 모드 명령Test mode command	임의option	Bit fieldBit field
RFURFU	22

At least one voltage set value determined according to a situation (eg, minimum voltage value information VRECT_MIN_DYN of the rear end of the rectifier of the wireless power receiver 750, and optimum voltage value information VRECT_SET_DYN of the rear end of the rectifier of the wireless power receiver 750). ), The maximum voltage value information (VRECT_HIGH_DYN, etc.) of the rear end of the rectifier of the wireless power receiver may be included in the corresponding field of the PRU dynamic signal and transmitted. As such, the wireless power transmitter 700 receiving the PRU dynamic signal may adjust the wireless charging voltage to be transmitted to each wireless power receiver 750 with reference to the voltage setting values included in the PRU dynamic signal.

Among them, the alert information PRU Alert may be formed of a data structure as shown in Table 3 below.

77	66	55	44	33	22	1One	00
과전압Overvoltage	과전류Overcurrent	과온도Overtemperature	무선 전력 수신기 셀프 보호Wireless power receiver self protection	충전 완료Charging complete	유선 충전 감지Wired charge detection	무선 전력 수신기 충전 포트Wireless power receiver charging port	전원 응답 조정Power response adjustment

Referring to Table 3, the warning information includes over voltage, over current, over temperature, wireless power receiver 750 PRU Self Protection, charge complete, The device may include a wired charger detect, a wireless power receiver 750 charge port, and an adjust power response.

Meanwhile, the wireless power receiver 750 may detect an error occurrence. The wireless power receiver 750 may transmit a warning signal to the wireless power transmitter 700 (S721). The alert signal may be transmitted as a PRU dynamic signal or as an alert signal. For example, the wireless power receiver 750 may transmit to the wireless power transmitter 700 by reflecting an error condition in the PRU alert field of Table 5 above. Alternatively, the wireless power receiver 750 may transmit a single warning signal indicating the error situation to the wireless power transmitter 700. When the wireless power transmitter 700 receives the warning signal, the wireless power transmitter 700 may enter a latch fault mode (S722). The wireless power receiver 750 may enter a null state (S723).

Referring to FIG. 8, each of the NFC devices performing a peer to peer (P2P) mode may serve as an NFC initiator and an NFC target.

NFC communication uses a frequency band of 13.56 MHz and is a kind of electronic tag (RFID) technology that enables fast two-way communication between NFC devices. As an example, NFC communication is a short-range wireless communication technology that is capable of transmitting power and signals by mounting a wireless power transceiver. to be. NFC communication can support the transmission and reception of data in both directions at a distance of less than 10cm.

In the case of the electromagnetic induction method, considering that the distance between the wireless power transceiver is very small, the distance between the wireless power transceiver, it is preferable to use NFC communication for wireless power transmission by the electromagnetic resonance method of the wireless power transmission method.

Using NFC communication, power transmission can be performed only by tagging (identifying in close proximity) between wireless power transceivers.

NFC communication may be classified into a card mode, an RFID reader mode, and a P2P mode according to an operation mode. NFC communication can provide various mobile payment methods such as transportation cards and discount coupons with contactless smart card technology and security in card mode, and website connection using smart posters with RFID tags as well as NFC devices in RFID reader mode. And information acquisition, and each of the NFC devices in the P2P mode, which is a bidirectional communication mode, may operate to transmit and receive data and share files with each other.

Each NFC device may perform bidirectional information exchange in a P2P mode. In P2P mode, Logical Link Control Protocol (LLCP) is generally used to establish data links and perform activation, deactivation and management operations.

NFC communication is accomplished by NFC devices with embedded NFC tags. In detail, NFC communication is performed by generating a current due to electromagnetic induction while a magnetic field change occurs between a first NFC device including an NFC tag and an NFC coil antenna and an NFC coil antenna included in another second NFC device. In other words, a magnetic field change occurs between the NFC coil antenna, a current is generated by the electromagnetic induction phenomenon, and communication between devices is made using this current.

NFC communication may be divided into an active mode for reader and reader communication and a passive mode for reader and tag communication.

In the active mode, NFC initiators 810 serving as readers and NFC targets 820 serving as tags may be classified according to roles.

The NFC initiator 810 may provide a carrier field to the NFC target 820 and the NFC target 820 may respond by modulating the current electromagnetic field. NFC target 820 is also referred to as a wireless transponder (Transponder) because it operates by being powered by the electromagnetic field provided by the NFC initiator 810. That is, the NFC initiator 810 may selectively transmit the NFC signal having the driving power of the NFC target 820. The NFC initiator 810 and the NFC target 820 both serve as a power supply, and may selectively generate and communicate with an electric field by division according to a role. When any one of the NFC initiator 810 and the NFC target 820 receives data, it may operate as the NFC target 820 by deactivating the high frequency electromagnetic field.

The NFC initiator 810 searches for the surrounding RF field signal, and transmits an RF field signal when it is not detected (S830).

The NFC initiator 810 transmits an initial command signal at a specific frequency (S850). After receiving the initial command signal, the NFC target 820 digitally processes the initial command signal and transmits a response signal at the same frequency (S870).

Since the NFC initiator 810 and the NFC target 820 are classified according to their roles for signal transmission and reception, the wireless power transceiver may assume the roles of the NFC initiator 810 and the NFC target 820 according to a situation of receiving an initial command signal. Can be.

In other words, according to circumstances, the wireless power transmitter may serve as the NFC initiator 810, and the wireless power receiver may serve as the NFC target 820. In contrast, the wireless power receiver may serve as the NFC initiator 810, and the wireless power transmitter may serve as the NFC target 820.

Referring to FIG. 9, the wireless power transmitter may include a controller 910 and an NFC module 920, and the wireless power receiver may also include a controller 930 and an NFC module 940.

The controller 910 of the wireless power transmitter performs overall control for power transmission to the wireless power receiver, controls the NFC module 920 to search for the wireless power receiver, and the found wireless power receiver and control signals related to power transmission. Can be sent.

Although not shown in FIG. 9, the controller 910 of the wireless power transmitter may control the Bluetooth module performing Bluetooth communication (BLE communication) together with the wireless power receiver, and at least any one of BLE communication or NFC communication according to a situation. One can transmit and receive control signals.

For example, in a situation where the beacon signal intensity according to BLE communication is less than a certain size, the Bluetooth module is deactivated for the NFC communication and the NFC module is activated to perform the discovery and authentication process of the wireless power receiver by the NFC module. Can be controlled.

The controller 910 of the wireless power transmitter may set a connection parameter to the NFC module 920 before starting the search of the wireless power receiver (S901).

The connection parameter may include identification information for identifying the wireless power transmitter, and the wireless power receiver is a wireless power transmitter that is eligible to form an NFC communication channel for wireless power transmission via the connection parameter received from the wireless power transmitter. It can be determined.

The NFC module 920 may be based on a logical link protocol (LLCP) in the determination. The LLCP defines a specific way of differently reading or writing data of the NFC module 92.

For example, before establishing a communication session for wireless power transmission, the wireless power receiver may determine whether the wireless power transmission standard that the wireless power transmitter can support is the A4WP standard through the connection parameter of the wireless power transmitter.

The controller 910 may command the NFC module 920 to search for the wireless power receiver while setting the connection parameters (S902).

The NFC module 920 commanded to search for the wireless power receiver from the controller 910 searches for an RF field signal at a low level (low power level). The wireless power transmitter, as an NFC initiator, may periodically transmit a signal for searching for a wireless power receiver as an NFC target (S905).

The NFC module 920 of the wireless power transmitter may selectively transmit a discovery signal having power capable of driving the NFC module 930 of the wireless power receiver.

In the A4WP standard using BLE communication, driving power by beacon signals is transmitted to cause the wireless power receiver to generate an advertisement signal. In other words, in the case of the A4WP standard, transmission and reception of the power transmission signal and the advertisement signal are required. In contrast, when the NFC communication is used, power to drive the NFC module 930 of the wireless power receiver is transferred to the discovery signal. This allows for faster discovery of the wireless power receiver during identification.

NFC module 920 may detect proximity of the wireless power receiver as an NFC target using as little power as possible. Specifically, the detection of the NFC target can be accomplished by comparing the oscillator frequency with a known reference frequency.

For example, using a calibrated low power oscillator (LPO) to monitor the frequency oscillations associated with the NFC antenna, and then determine whether the number of occurrences of frequency oscillations from the reference frequency has a value greater than the frequency deviation threshold. Can be.

As another example, when the value of at least one of the current or voltage derived from the NFC antenna exceeds a preset value, another NFC device may be detected.

In this case, when the wireless power receiver is positioned within a specific distance (for example, 10 cm) from the wireless power transmitter, the search is performed by receiving a response signal for the corresponding signal from the wireless power receiver.

Meanwhile, the controller 940 of the wireless power receiver may set a connection configuration parameter to the NFC module 930 (S903).

The connection configuration parameter may include identification information for identifying the wireless power receiver, and the wireless power transmitter may determine whether the wireless power receiver is eligible to receive wireless power transmission through the connection configuration parameter.

The controller 940 may set a connection configuration parameter and instruct the NFC module 930 to search for the wireless power transmitter (S904).

When the wireless power transmitter searches for the wireless power receiver, the wireless power transmitter may generate a connection activation signal including connection parameter information for identifying the wireless power transmitter (S906).

The wireless power transmitter transmits the generated connection activation signal to the NFC module 930 of the wireless power receiver (S907), and the NFC module 930 receiving the connection activation signal may identify connection configuration parameter information for the wireless power receiver. A response signal including a may be generated (S908).

The NFC module 930 transmits a response signal corresponding to the connection activation signal to the NFC module 920 of the wireless power transmitter (S920), and the NFC module 920 controls the connection configuration parameter of the detected wireless power receiver 910. (S930).

The controller 910 of the wireless power transmitter may end the process of identifying and recognizing the wireless power receiver by receiving the connection configuration parameter.

The NFC module 930 of the wireless power receiver may transmit a response signal to the wireless power transmitter, and then transfer the connection parameters of the wireless power transmitter detected by the controller 940 (S911).

The controller 940 of the wireless power receiver may identify the wireless power transmitter and terminate the discovery and recognition process through the connection parameters of the wireless power transmitter.

Thereafter, the wireless power transceiver may periodically transmit and receive each state information using the formed NFC communication channel.

Here, the state information may include, but is not limited to, rectifier output voltage strength information and strength information of a voltage applied to a load. In addition, the failure / alarm status information may include, but is not limited to, overvoltage / overcurrent detection information, overheating information, timer expiration information, and charging completion information.

In one embodiment, each of the wireless power transceivers may receive respective identification information or status information via an NFC communication channel. The identification information of the wireless power transceiver may be specification information related to standards of wireless power transmission (eg, WPC, PMA, A4WP, and Airfuel) that the wireless power transceiver can support.

The wireless power transceiver may transmit and receive mounting position and shape information of the transmitting coil on the wireless power transmitter, and / or mounting position and shape information of the receiving coil on the wireless power receiver, in addition to a signal defined by a standard body using BLE communication. Each of the wireless power transceivers may use this information to identify the alignment state of the transmitting coil and the receiving coil and output the information on the identified alignment state.

For example, each of the wireless power transceivers may transmit and receive location information of the transmission / reception coils included in the wireless power transceiver, and may transmit and receive a signal instructing to change the location of the transmission / reception coils (antennas) for alignment to increase charging efficiency. .

In addition, the wireless power transceiver according to an embodiment of the present invention may calculate the current charging efficiency based on the received power reception state information, the information about the calculated charging efficiency may be transmitted to each other via NFC communication.

Referring to FIG. 10, the wireless power receiver may include a controller 1010 and an NFC module 1020, and the wireless power transmitter may include a controller 1030 and an NFC module 1040.

The controller 1010 of the wireless power receiver may control the NFC module 920 to search for a wireless power receiver and transmit a control signal related to power transmission with the found wireless power receiver.

The controller 1010 of the wireless power receiver may set a connection parameter to the NFC module 1020 before starting to search for the wireless power transmitter (S1001).

The connection parameter may include identification information for identifying the wireless power receiver, and whether the wireless power transmitter is a wireless power receiver that is eligible to form a communication channel for wireless power transmission via the connection parameter received from the wireless power receiver. Can be determined.

The controller 1010 may command the NFC module 1020 to search for the wireless power transmitter while setting the connection parameters (S1002).

The NFC module 1020 commanded to search for the wireless power transmitter from the controller 1010 searches for an RF field signal at a low level (low power level). Contrary to FIG. 9, the wireless power receiver may transmit a signal to find a wireless power transmitter as an NFC initiator and periodically as an NFC target.

In this case, when the wireless power transmitter is positioned within a specific distance (for example, 10 cm) from the wireless power receiver, the search is performed by receiving a response signal corresponding to the corresponding signal from the wireless power transmitter (S1005).

Meanwhile, the controller 1040 of the wireless power transmitter may set a connection configuration parameter to the NFC module 1030 (S1003). The connection configuration parameter may include identification information for identifying the wireless power transmitter.

The controller 1040 may set a connection configuration parameter and instruct the NFC module 1030 to search for the wireless power receiver (S1004).

When the wireless power receiver searches for the wireless power transmitter, the wireless power receiver may generate a connection activation signal including connection parameter information for identifying the wireless power receiver (S1006).

The wireless power receiver transmits the generated connection activation signal to the NFC module 1030 of the wireless power transmitter (S1007), and the NFC module 1030 receiving the connection activation signal may identify the connection configuration parameter information of the wireless power transmitter. It may generate a response signal containing (S1008).

The NFC module 1030 transmits a response signal corresponding to the connection activation signal to the NFC module 1020 of the wireless power receiver (S1020), and the NFC module 1020 controls the connection configuration parameter of the detected wireless power transmitter 1010. In step S1030.

The controller 1010 of the wireless power receiver may end the process of identifying and recognizing the wireless power transmitter by receiving the connection configuration parameter.

The NFC module 1030 of the wireless power transmitter may transmit a response signal to the wireless power receiver and then transfer the connection parameters of the wireless power receiver detected by the controller 1040 (S1011).

The controller 1040 of the wireless power transmitter may identify the wireless power receiver and terminate the discovery and recognition process through the connection parameter of the wireless power receiver.

Thereafter, the wireless power transceiver may transmit and receive each state information using the formed NFC communication channel.

Referring to FIG. 11, the wireless power transmitter includes a control unit 1110, an NFC module 1121, and a communication unit 120 including a Bluetooth module 1122, and a wireless charging coil 1131 and an NFC coil 1132 integrally formed. It may include an antenna 1132. The components shown in FIG. 11 are not essential, such that a wireless power transmitter with more or fewer components may be implemented. A wireless power receiver paired with a wireless power transmitter according to an embodiment of the present invention may also have a similar structure.

Hereinafter, the components will be described in detail.

The controller 1110 may control the overall operation of the power transmission of the wireless power transmitter. Before the search for the wireless power receiver, standard information to which the wireless power transmitter is applied, and authentication and identification information according thereto may be transmitted to the communication unit 1120 to control modulation to a specific frequency.

The communication unit 1120 may include an NFC module 1121 capable of performing NFC communication and a Bluetooth module 1122 capable of performing BLE communication.

The communicator 1120 may activate one of the NFC module 1121 and the Bluetooth module 1122 and deactivate the other according to the strength of the signal received from the NFC module 1121 and the Bluetooth module 1122.

The antenna 1132 may have a form of an integrated coil including an antenna 1131 for transmitting power energy and an NFC antenna 1132 provided separately from the outside of the antenna. The wireless power transmitter may control pairing between wireless power transceivers for wireless power transmission using an integrated coil.

The wireless power transmitter may include a controller 1110 for controlling the antenna 1131 for wireless power transmission and the antenna 1132 for performing NFC communication.

According to an embodiment, the controller 1110 may time-division a wireless power signal and a short range wireless communication signal for wireless power transmission and transmit the same to the wireless power receiver.

Since an error may occur in a signal due to interference between a magnetic field generated from the antenna 1131 for wireless power transmission and a magnetic field generated from the antenna 1132 performing NFC communication, the control unit 1110 transmits time-divided signals. Can be controlled.

The method according to the embodiment described above may be stored in a computer-readable recording medium that is produced as a program for execution on a computer, and examples of the computer-readable recording medium include ROM, RAM, CD-ROM, magnetic tape , Floppy disks, optical data storage, and the like, and also include those implemented in the form of carrier waves (eg, transmission over the Internet).

The computer readable recording medium can be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. In addition, functional programs, codes, and code segments for implementing the above-described method may be easily inferred by programmers in the art to which the embodiments belong.

It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit and essential features of the present invention. Thus, the above detailed description is to be considered in all respects as illustrative and not restrictive. Should be. The scope of the invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the invention are included in the scope of the invention.

The wireless power transmitter control method and the wireless power receiver control method according to the embodiment may be used in a wireless power transmitter and a wireless power receiver including a short range communication antenna.

Claims

Transmitting a first near field communication (NFC) signal having driving power of a communication unit included in the wireless power receiver;

Recognizing the wireless power receiver through a response signal to the first short range communication signal;

Transmitting a second near field communication signal for establishing a near field communication (NFC) channel as a communication channel for wireless power transmission with the communication unit; And

Transmitting and receiving status information signals related to wireless power transmission and reception through the established short range communication channel;

Including;

Wireless power transmitter control method.
The method of claim 1,

The first short range communication signal is a signal for periodically searching for an NFC tag included in the wireless power receiver.

Wireless power transmitter control method.
The method of claim 1,

The communication unit,

NFC module for performing near field communication (NFC); And

A Bluetooth module for performing Bluetooth communication;

Including,

Wireless power transmitter control method.
The method of claim 1,

Activating any one of an NFC module performing Near Field Communication (NFC) and a Bluetooth module performing Bluetooth communication according to the strength of the second near field communication signal;

Further comprising,

Wireless power transmitter control method.
The method of claim 1,

Transmitting and receiving the status information signal,

Which is performed at regular intervals,

Wireless power transmitter control method.
Transmitting a first Near Field Communication (NFC) signal searching for a wireless power transmitter;

Recognizing the wireless power transmitter through a response signal to the first short range communication signal;

Transmitting a second near field communication signal to establish a near field communication (NFC) channel as a communication channel for receiving wireless power from the wireless power transmitter; And

Transmitting and receiving status information signals related to wireless power transmission and reception through the established short range communication channel;

Including;

Wireless power receiver control method.
The method of claim 6,

The first short range communication signal is a signal for periodically searching for an NFC tag included in the wireless power transmitter.

Wireless power receiver control method.
The method of claim 6,

Activating any one of an NFC module performing Near Field Communication (NFC) and a Bluetooth module performing Bluetooth communication according to the strength of the second near field communication signal;

Further comprising,

Wireless power receiver control method.
The method of claim 6,

Transmitting and receiving the status information signal,

Which is performed at regular intervals,

Wireless power receiver control method.
A computer-readable recording medium having recorded thereon a program for executing the method according to any one of claims 1 to 9.