KR20170124894A - Wireless power transmission mode switching method and apparatus - Google Patents

Abstract

The present invention relates to a wireless power transmission mode switching method and apparatus. A method of controlling a power receiving unit (PRU) according to an embodiment of the present invention includes a step of calculating reception efficiency using the capability information of a PTU (Power Transmission Unit) included in a PTU static signal and at least one parameter measured inside; a step of requesting switching from a first wireless power transmission scheme to a second wireless power scheme using a warning field (PRU alert field) to the PTU if the reception efficiency is lower than a switching threshold; and a step of changing setting to the second wireless power transmission scheme if a switching allowance message is received from the wireless power transmitter.

Description

TECHNICAL FIELD [0001] The present invention relates to a wireless power transmission mode switching method and apparatus,

The present invention relates to wireless power transmission, and more particularly, to a method and apparatus for switching a wireless power transmission mode.

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

2. Description of the Related Art [0002] Generally, as an example of an electrical connection between a charging device and a battery for charging electric power of a battery, a commercial electric power is supplied to a terminal for converting electric power into voltage and current corresponding to the battery, Supply method. This type of terminal supply is accompanied by the use of physical cables or wires. Therefore, when handling a lot of terminal-supplied equipment, many cables occupy considerable work space, are difficult to organize, and are not well apparent. Also, the terminal supply method may cause problems such as instantaneous discharge due to different potential difference between terminals, burnout due to foreign substances, fire, natural discharge, battery life and deterioration of performance.

In order to solve such a problem, a charging system (hereinafter referred to as a "wireless charging system") and a control method using a method of transmitting power wirelessly are proposed. In addition, since the wireless charging system has not been installed in some portable terminals in the past and the consumer has to purchase a separate wireless charging receiver accessory, the demand for the wireless charging system is low, but the wireless charging user is expected to increase rapidly. Wireless charging function is expected to be equipped basically.

Generally, a wireless charging system comprises a wireless power transmitter for supplying electric energy in a wireless power transmission mode and a wireless power receiver for receiving electric energy supplied from a wireless power transmitter to charge the battery.

Such a wireless charging system may transmit power by at least one wireless power transmission scheme (e.g., electromagnetic induction scheme, electromagnetic resonance scheme, RF wireless power transmission scheme, etc.).

For example, the wireless power transmission scheme may use various wireless power transmission standards based on an electromagnetic induction scheme in which a magnetic field is generated in a power transmission terminal coil and charged using an electromagnetic induction principle in which electricity is induced in a reception terminal coil due to the magnetic field . Here, the electromagnetic induction type wireless power transmission standard may include an electromagnetic induction wireless charging technique defined in a Wireless Power Consortium (WPC) or a Power Matters Alliance (PMA).

In another example, the wireless power transmission scheme may employ an electromagnetic resonance scheme in which the magnetic field generated by the transmission coil of the wireless power transmitter is tuned to a specific resonance frequency to transmit power to a nearby wireless power receiver . Here, the electromagnetic resonance method may include a resonance-type wireless charging technique defined in the Alliance for Wireless Power (A4WP) standard mechanism, a wireless charging technology standard mechanism.

In another example, a wireless power transmission scheme may use an RF wireless power transmission scheme that transmits power to a wireless power receiver located at a remote location by applying low-power energy to the RF signal.

The wireless charging system may be designed to support at least two of the above-described electromagnetic induction, electromagnetic resonance, and RF wireless power transmission schemes. In other words, the wireless power transmitter can be designed to transmit power to the wireless power receiver through a plurality of wireless power transmission schemes.

Accordingly, there is a need for a concrete scheme for switching a power transmission scheme among a plurality of wireless power transmission schemes in one wireless charging system.

It is an object of the present invention to provide a wireless power transmission mode switching method and apparatus.

The present invention provides a method for switching a wireless power transmission scheme by a wireless power transceiver in a wireless charging system supporting an electromagnetic induction scheme and an electromagnetic resonance scheme.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, unless further departing from the spirit and scope of the invention as defined by the appended claims. It will be possible.

According to another aspect of the present invention, there is provided a method of switching a wireless power transmission mode in a wireless power receiver, the method comprising: Calculating a reception efficiency using at least one of the capability information of the PTU, the power transmission unit, and at least one parameter measured inside; Requesting switching from a first wireless power transmission scheme to a second wireless power scheme using a PRU alert field to the wireless power transmitter if the reception efficiency is lower than a switching threshold; And upon receiving a switching grant message from the wireless power transmitter, changing the setting to the second wireless power transmission scheme; . ≪ / RTI >

According to an exemplary embodiment of the present invention, the step of requesting the switching may include the step of, in the first wireless power transmission scheme, using the Mode Transition bit of the PRU alert field included in the PRU alert characteristic signal, 2 wireless power transmission scheme; . ≪ / RTI >

According to an embodiment of the present invention, the step of calculating the reception efficiency may include calculating reception efficiency using the voltage information and the current information measured internally; . ≪ / RTI >

According to an embodiment, the step of changing the setting to the second wireless power transmission mode may include the steps of: performing a communication connection for power transmission in the second wireless power transmission scheme, or performing power transmission in the second wireless power transmission scheme Changing a setting to the first wireless power transmission scheme when the communication connection for the first wireless power transmission scheme is not performed within a predetermined time; . ≪ / RTI >

In accordance with another aspect of the present invention, there is provided a method of switching a wireless power transmission mode in a wireless power transmitter, the method comprising: receiving a first wireless power transmission from a wireless power receiver (PRU) Receiving a PRU alert characteristic signal requesting switching from a scheme to a second wireless power transmission scheme; Determining whether to switch from the first wireless power transmission scheme to the second wireless power scheme according to a PRU alert field included in the PRU alert characteristic signal; And performing a transition to the second wireless power transmission scheme according to the determination; . ≪ / RTI >

Transmitting a PTU static signal including capability information on power transmission to the wireless power receiver according to an embodiment; As shown in FIG.

According to an embodiment, performing the switching to the second wireless power transmission scheme according to the determination may comprise: transmitting a switching grant message to the wireless power receiver; . ≪ / RTI >

The step of determining whether to switch from the first wireless power transmission scheme to the second wireless power scheme according to an alert field (PRU alert field) included in the PRU alert characteristic signal may include: Determining whether to switch from the first wireless power transmission scheme to the second wireless power scheme according to a mode transition bit of the alert field (PRU alert field) included in the signal; . ≪ / RTI >

The step of determining whether to switch from the first wireless power transmission scheme to the second wireless power scheme according to an alert field (PRU alert field) included in the PRU alert characteristic signal may include: And determining whether to switch from the first wireless power transmission scheme to the second wireless power scheme using state information of the receiver.

The step of determining whether to switch from the first wireless power transmission scheme to the second wireless power transmission scheme using the state information of the wireless power receiver according to the embodiment may include determining whether to switch from the first wireless power transmission scheme to the second wireless power transmission scheme, Calculating transmission efficiency using at least one of the transmission power and the transmission power and determining whether to switch to the second wireless power transmission scheme according to the transmission efficiency; . ≪ / RTI >

According to an embodiment, the alert field includes a Mode Transition bit, and may include over voltage, over current, over temperature, wireless power receiver self protection, , A charge complete, and a wired charge detector (Wired Charge Detect).

According to an embodiment, the bit for indicating the mode change is a preset value, and the over voltage, the over current, the over temperature, the wireless power receiver self protection (PRU Self Protection) determining whether to switch to the second wireless power transmission scheme considering at least one of a charge complete and a bit indicating a wired charge detection; . ≪ / RTI >

According to an embodiment, performing the switching to the second wireless power transmission scheme according to the determination comprises: adjusting a current (I _{TX - COIL} ) applied to a coil included therein to a preset current; . ≪ / RTI >

According to an embodiment of the present invention, the step of adjusting the current (I _{TX - COIL} ) applied to the coil included therein to a predetermined current may be performed simultaneously with the first radio power transmission method and the second radio power transmission method If present, _adjusting the current (I _{TX - COIL} ) to a predetermined current; Blocking and adjusting the current (I _{TX - COIL} ) if the first wireless power transmission scheme and the second wireless power transmission scheme can not be performed at the same time; . ≪ / RTI >

According to an embodiment, performing the switching to the second wireless power transmission scheme according to the determination may comprise: if a communication connection is not performed for power transmission to the wireless power receiver and the second wireless power transmission scheme, Performing wireless power transmission in the first wireless power transmission mode when a communication connection for power transmission to the wireless power receiver is not performed within a predetermined time period; . ≪ / RTI >

According to the embodiment, the present invention can provide a computer-readable recording medium on which a program for executing the above-described method is recorded.

In addition, a power receiving unit (PRU) according to an embodiment of the present invention includes a communication unit for receiving a PTU static signal including capability information from a wireless power transmitter (PTU); And calculating a reception efficiency using at least one of the capability information and at least one parameter measured in the inside, and when the reception efficiency is lower than a switching threshold, using a PRU alert field with the wireless power transmitter A controller for requesting switching from a first wireless power transmission scheme to a second wireless power transmission scheme and changing a setting to the second wireless power transmission scheme upon receiving a switching grant message from the wireless power transmitter; . ≪ / RTI >

According to an embodiment of the present invention, the control unit may perform the second wireless power transmission in the first wireless power transmission scheme by using a mode transition bit of the PRU alert field included in the PRU alert characteristic signal, Switching can be requested.

According to the embodiment, the controller may calculate the reception efficiency using at least one of the voltage information and the current information measured internally.

According to an embodiment of the present invention, the control unit may be configured such that a communication connection for power transmission is not performed in the second wireless power transmission mode, or a communication connection for power transmission in the second wireless power transmission mode is not performed within a predetermined time The setting can be changed to the first wireless power transmission scheme.

In addition, a power transmission unit (PTU) according to an embodiment of the present invention transmits a request for switching from a first wireless power transmission scheme to a second wireless power transmission scheme from a wireless power receiver (PRU) A communication unit for receiving a PRU alert characteristic signal; And determining whether to switch from the first wireless power transmission scheme to the second wireless power scheme according to a PRU alert field included in the PRU alert characteristic signal, A control unit for performing switching to a transmission mode; . ≪ / RTI >

According to an embodiment, the communication unit may transmit a PTU static signal including capability information on power transmission to the wireless power receiver.

According to an embodiment, the communication unit may transmit a switching permission message to the wireless power receiver.

According to an embodiment of the present invention, the controller may control the second wireless power transmission scheme in the first wireless power transmission scheme according to a mode transition bit of the PRU alert field included in the PRU alert characteristic signal, Or not.

According to an embodiment, the controller may determine whether to switch from the first wireless power transmission scheme to the second wireless power transmission scheme using state information of the wireless power receiver.

According to an embodiment of the present invention, the control unit may calculate transmission efficiency using at least one of voltage information and current information of the wireless power receiver, and determine whether to switch to the second wireless power transmission scheme according to the transmission efficiency .

According to an embodiment, the alert field includes a Mode Transition bit, and may include over voltage, over current, over temperature, wireless power receiver self protection, , A charge complete, and a wired charge detector (Wired Charge Detect).

According to an embodiment of the present invention, the control unit may be configured such that the bit indicating the mode change is a preset value, and the over voltage, the over current, the over temperature, the wireless power receiver self protection ), A charge complete, and a bit indicating a wired charge detection (Wired Charge Detect) to determine whether to switch to the second wireless power transmission scheme.

According to an embodiment, the controller may adjust a current (I _{TX - COIL} ) applied to a coil included therein to a preset current.

According to an embodiment of the present invention, when the first radio power transmission method and the second radio power transmission method can be performed simultaneously, the controller may adjust the current (I _{TX - COIL} ) If one wireless power transmission system and the second wireless power transmission method can not be performed at the same time, it can be adjusted to cut off the current (I _{_COIL TX).}

According to an embodiment, the control unit may be configured to determine whether a communication connection for power transmission to the wireless power receiver is not performed, or if the connection is not established within a predetermined time period between the wireless power receiver and the second wireless power transmission If the communication connection for power transmission is not performed, the wireless power transmission can be performed in the first wireless power transmission mode.

Effects of the wireless power transmission mode switching method and apparatus according to the present invention are as follows.

First, according to the present invention, a plurality of wireless power transmission schemes can be used to select a wireless power transmission scheme that is efficient according to a situation, thereby enhancing transmission efficiency.

Second, the present invention can define a specific communication protocol for switching the wireless power transmission scheme while utilizing the published wireless power transmission standard.

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

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. It is to be understood, however, that 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 a new embodiment.
1 is a block diagram illustrating a structure of a wireless power transmission system of an electromagnetic resonance method 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 for explaining a state transition procedure in a wireless power transmitter of an electromagnetic resonance system according to an embodiment of the present invention.
4 is a state transition diagram of an electromagnetic resonance type wireless power receiver according to an embodiment of the present invention.
5 is a view for explaining an operation region of a wireless power receiver of an electromagnetic resonance type according to a VRECT according to an embodiment of the present invention.
6 is a flowchart illustrating a wireless charging procedure of an 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 multimode wireless power transmission scheme according to an embodiment of the present invention.
8 is a flowchart illustrating an operation of a wireless power receiver supporting a multimode wireless power transmission scheme according to an embodiment of the present invention.
9 is a flowchart illustrating an operation of a wireless power transmitter supporting a multimode wireless power transmission scheme according to an embodiment of the present invention.
10 is a flowchart illustrating operations of a wireless power transmitter and a wireless power receiver supporting a multimode wireless power transmission scheme according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an apparatus and various methods to which embodiments of the present invention are applied will be described in detail with reference to the drawings. The suffix "module" and " part "for the components used in the following description are given or mixed in consideration of ease of specification, and do not have their own meaning or role.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. That is, within the scope of the present invention, all of the components may be selectively coupled to one or more of them. In addition, although all of the components may be implemented as one independent hardware, some or all of the components may be selectively combined to perform a part or all of the functions in one or a plurality of hardware. As shown in FIG. The codes and code segments constituting the computer program may be easily deduced by those skilled in the art. Such a computer program can be stored in a computer-readable storage medium, readable and executed by a computer, thereby realizing an embodiment of the present invention. As the storage medium of the computer program, a magnetic recording medium, an optical recording medium, a carrier wave medium, or the like may be included.

In the description of the embodiment, in the case of being described as being formed on the "upper or lower", "before" or "after" of each component, (Lower) "and" front or rear "encompass both that the two components are in direct contact with each other or that one or more other components are disposed between the two components.

It is also to be understood that the terms such as " comprises, "" comprising," or "having ", as used herein, mean that a component can be implanted unless specifically stated to the contrary. But should be construed as including other elements. All terms, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. Commonly used terms, such as predefined terms, should be interpreted to be consistent with the contextual meanings of the related art, and are not to be construed as ideal or overly formal, unless expressly defined to the contrary.

In describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the constituent elements from other constituent elements, and the terms do not limit the nature, order or order of the constituent elements. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected to or connected to the other component, It should be understood that an element may be "connected," "coupled," or "connected."

In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

In the description of the embodiments, an apparatus for transmitting wireless power on a wireless power charging system includes a wireless power transmitter, a wireless power transmitter, a wireless power transmitter, a wireless power transmitter, a transmitter, a transmitter, a transmitter, , A wireless power transmission device, a wireless power transmitter, a wireless charging device, and the like. For the sake of convenience, a wireless power receiving device, a wireless power receiving device, a wireless power receiving device, a wireless power receiving device, a receiving terminal, a receiving side, a receiving device, a receiver Terminals and the like can be used in combination.

The wireless charging device according to the present invention may be configured as a pad type, a cradle type, an access point (AP) type, a small base type, a stand type, a ceiling embedded type, Power may be transmitted to the device.

As an example, a wireless power transmitter can be used not only on a desk or on a table, but also developed for automobiles and used in a vehicle. A wireless power transmitter installed in a vehicle can be provided in a form of a stand that can be easily and stably fixed and mounted.

The terminal according to the present invention may be used in a mobile phone, a smart phone, a laptop computer, a digital broadcasting terminal, a PDA (Personal Digital Assistants), a PMP (Portable Multimedia Player), a navigation device, an MP3 player, (Hereinafter referred to as a " device ") capable of charging a battery by mounting a wireless power receiving means according to the present invention, but not limited thereto, can be used for a small electronic device such as a toothbrush, an electronic tag, Quot;), and the term terminal or device may be used in combination. The wireless power receiver according to another embodiment of the present invention can also be mounted on a vehicle, an unmanned aerial vehicle, an air drone or the like.

A wireless power receiver according to an exemplary embodiment of the present invention may include at least one wireless power transmission scheme and may simultaneously receive wireless power from two or more wireless power transmitters. Here, the wireless power transmission scheme may include at least one of the electromagnetic induction scheme, the electromagnetic resonance scheme, and the RF wireless power transmission scheme.

Generally, a wireless power transmitter and a wireless power receiver that constitute a wireless power system can exchange control signals or information through in-band communication or Bluetooth low energy (BLE) communication. Here, the in-band communication and the BLE communication can 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, and the like. For example, the wireless power receiver can 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 reception coil in a predetermined pattern. The information transmitted by the wireless power receiver may include various status information including received power intensity information. At this time, the wireless power transmitter can calculate the charging efficiency or the power transmission efficiency based on the received power intensity information.

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 schemes among the electromagnetic induction method, the electromagnetic resonance method, and the RF wireless power transmission method.

Among them, a wireless power transmission scheme supporting electromagnetic induction and electromagnetic resonance is defined as a multimode wireless power transmission scheme. The operation in each channel of the wireless power transmission scheme supporting the multimode wireless power transmission scheme can be performed according to the electromagnetic induction scheme and the electromagnetic resonance scheme, respectively.

Hereinafter, the electromagnetic resonance method in the wireless power transmission system will be described with reference to Figs. 1 to 6, and the method of switching the charging mode in the electromagnetic induction system to the electromagnetic resonance system will be described with reference to Figs.

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

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

Although the wireless power transmitter 100 is shown in FIG. 1 as transmitting wireless power to one wireless power receiver 200, this is only one embodiment, and the wireless power 100 according to another embodiment of the present invention Transmitter 100 may also transmit wireless power to a plurality of wireless power receivers 200. It should be noted that the wireless power receiver 200 according to yet another embodiment may receive wireless power from a plurality of wireless power transmitters 100 simultaneously.

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. [

As an example, the frequency for power transmission may be, but is not limited to, the 6.78 MHz band.

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

The maximum number of wireless power receivers 200 capable of receiving power from one wireless power transmitter 100 is determined by the maximum transmission power level of the wireless power transmitter 100, the maximum power reception level of the wireless power receiver 200, May be determined based on the physical structure of the power transmitter 100 and the wireless power receiver 200.

The wireless power transmitter 100 and the wireless power receiver 200 can perform bidirectional communication in a frequency band different from the frequency band for the wireless power transmission, i.e., the resonance frequency band. For example, bi-directional communication may be a half-duplex Bluetooth low energy (BLE) communication protocol.

The wireless power transmitter 100 and the wireless power receiver 200 may exchange each other's characteristics and status information, i.e., power negotiation information, via the two-way communication.

In one example, the wireless power receiver 200 may transmit certain power reception state information for controlling the power level received from the wireless power transmitter 100 to the wireless power transmitter 100 via bi-directional communication, 100 can dynamically control the transmission power level based on the received power reception state information. Accordingly, the wireless power transmitter 100 not only can optimize the power transmission efficiency, but also has a function of preventing a load breakage due to an over-voltage, a function of preventing unnecessary power from being wasted due to an under-voltage And the like can be provided.

The wireless power transmitter 100 also performs functions such as authenticating and identifying the wireless power receiver 200 through bidirectional communication, identifying incompatible devices or non-rechargeable objects, identifying a valid load, and the like You may.

Hereinafter, a wireless power transmission process in a resonance mode will be described in more detail with reference to FIG.

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

The power supply unit 110 may supply a specific supply voltage to the power conversion unit 120 under the control of the main control unit 150. At this time, the supply voltage may be a DC voltage or an AC voltage.

The power conversion unit 210 may convert the voltage received from the power supply unit 110 to a specific voltage under the control of the main control unit 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 impedances between the power conversion unit 210 and the transmission resonator 140 to maximize the power transmission efficiency.

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

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 may include a data transmitter and a data receiver.

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

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

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

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

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

In addition, the main control unit 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 when a system error state is detected The wireless power transmitter 100 may transmit the detection result to the wireless power transmitter 100 through the communication unit 260.

The main control unit 250 controls the operation of the rectifier 220 and the DC-DC converter 230 to prevent the load from being damaged when a system error condition is detected, or a predetermined overcurrent The power to be applied to the load 240 may be controlled by using a blocking circuit.

1, the main control units 150 and 250 and the communication units 160 and 260 are shown as being composed of different modules, but this is only one embodiment. In another embodiment of the present invention, 150, and 250 and the communication units 160 and 260 may be configured as a single module.

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.

In detail, Fig. 2 shows the interface points on the equivalent circuit in which the reference parameters to be described later are measured.

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

I _TX and I _{TX _COIL} denote the RMS (Root Mean Square) current applied to the matching circuit (or matching network) 201 of the wireless power transmitter and the RMS current applied to the transmitting resonator coil 202 of the wireless power transmitter, respectively do.

Z and Z _{TX TX _IN _IN_COIL} means the input impedance at each of the matching circuit 201. The input impedance of the front end (Input Impedance) and the matching circuit 201 and the rear end transmission resonator coil 202 of the wireless power transmitter front end.

L1 and L2 denote the inductance value of the transmission resonator coil 202 and the inductance value of the reception resonator coil 203, respectively.

Z _{RX _IN} means the input impedance of the matching circuit 204 and the rear end filter / rectifier / load 205, the front end of the wireless power receiver.

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

In addition, a wireless power transmission system according to an embodiment may provide simultaneous charging - i.e., multi-charging - for a plurality of wireless power receivers, in which case the remaining wireless power receivers Can 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 variation should not overlap the existing wireless power receiver when the wireless power receiver is added to or removed from the charging area.

When the matching circuit 204 of the wireless power receiver is connected to a 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, the increase of the R reduces _RECT Z _{TX _IN} and reduce the R _RECT can increase the Z _{TX _IN.}

The resonator coupling efficiency according to the present invention may be a maximum power reception ratio calculated by dividing the power transmitted from the receiving resonator coil to the load 204 by the power supplied to the resonant frequency band in the transmitting 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 shows examples 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 an embodiment of the present invention.

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

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

Referring to FIG. 3, the state of a wireless power transmitter is divided into a configuration state 310, a power save state 320, a low power state 330, a power transfer state 330, , 340, a Local Fault State 350, and a Latching Fault State 360.

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

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

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

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

In particular, Short Beacon sequences are generated repeatedly with a short period (t _{SHORT _BEACON)} a predetermined time interval (t _CYCLE) to be a standby power of the wireless transmitter power saving until the wireless power receiver detection may be transmitted. For example, t _{SHORT _BEACON} is less than 30ms, t _CYCLE can be respectively set to 250ms ± 5 ms. Also, the current intensity of the short beacon is not less than a predetermined reference value, and can be gradually increased for a predetermined time period. In one example, the minimum current intensity of the Short Beacon may be set high enough such that the category 2 or higher wireless power receiver of Table 2 can be detected.

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

Also, in the power saving state 320, the wireless power transmitter may periodically generate and transmit a second beacon sequence to provide sufficient power for the booting and response of the wireless power receiver. Hereinafter, for convenience of explanation, the second beacon and the second beacon sequence will be referred to as Long Beacon and Long Beacon sequences, respectively.

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

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

Thereafter, the wireless power transmitter may wait for the reception of a predetermined response signal during the long beacon transmission interval after the impedance change of the reception resonator is detected. Hereinafter, for convenience of explanation, the response signal will be referred to as an advertisement signal. Here, the wireless power receiver may broadcast an advertisement signal over an out-of-band communication frequency band that is different from the resonant frequency band.

In one example, the advertisement signal includes message identification information for identifying a message defined in the out-of-band communication standard, a unique service for identifying whether the wireless power receiver is legitimate or compatible with the wireless power transmitter, Information on the output power information of the wireless power receiver, information on the rated voltage / current applied to the load, information on the antenna gain of the wireless power receiver, information for identifying the category of the wireless power receiver, wireless power receiver authentication information, Information about whether or not the wireless power receiver is installed, and software version information mounted on the wireless power receiver.

The wireless power transmitter may establish an out-of-band communication link with the wireless power receiver after transitioning from a power saving state 320 to a low power state 330 upon receipt of an advertisement signal. Subsequently, the wireless power transmitter may perform the registration procedure for the wireless power receiver over the established out-of-band communication link. For example, if out-of-band communication is a Bluetooth low-power communication, the wireless power transmitter may perform Bluetooth pairing with the wireless power receiver and exchange at least one of the status information, characteristic information, and control information of each other via the paired Bluetooth link have.

When the wireless power transmitter transmits to the wireless power receiver a predetermined control signal for initiating charging via out-of-band communication in the low power state 330 (i.e., a predetermined control signal requesting the wireless power receiver to transmit 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 in the low power state 330 is not completed normally, the state of the wireless power transmitter may transition from the low power state 330 to the power saving state 320. [

The wireless power transmitter may be driven with a separate Link Expiration Timer for connection to each wireless power receiver and the wireless power receiver may transmit a predetermined message indicating that it is present in the wireless power transmitter at a predetermined time period Should be sent before the link expiration timer expires. The link expiration timer is reset each time the message is received, and the out-of-band communication link established between the wireless power receiver and the wireless power receiver may be maintained if the link expiration timer does not expire.

If all the 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 in the low power state 330 or the power transfer state 340, The power saving state 320 may be transited.

In addition, 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. At this time, if the registration timer expires, the wireless power transmitter in the low power state 330 may transition to the power saving state 320. At this time, the wireless power transmitter may output a predetermined notification signal notifying the registration failure through a notification display means provided in the wireless power transmitter, for example, an LED lamp, a display screen, a beeper, have.

Further, in the power transfer state 340, the wireless power transmitter may transition to the low power state 330 upon completion of charging all connected wireless power receivers.

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

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

At this time, the receiver status information transmitted from the wireless power receiver to the wireless power transmitter may include information on required power information, voltage and / or current information measured at the rear end of the rectifier, charge status information, overcurrent and / or overvoltage and / Information indicating whether or not the means for interrupting or reducing the electric power delivered to the load in accordance with the information, the overcurrent, or the overvoltage is activated. At this time, the receiver status information may be transmitted at a predetermined period or transmitted every time a specific event is generated. In addition, the means for interrupting or reducing the electric power delivered to the load in accordance with the overcurrent or overvoltage may be provided using at least one of an ON / OFF switch and a zener diode.

The receiver status information transmitted from the wireless power receiver to the wireless power transmitter according to another embodiment of the present invention includes information indicating that the external power is connected to the wireless power receiver by wire, information indicating that the out-of-band communication method is changed, And may be changed from NFC (Near Field Communication) to BLE (Bluetooth Low Energy) communication.

In accordance with another embodiment of the present invention, a wireless power transmitter is configured to determine a power intensity to be received by a wireless power receiver based on at least one of the currently available power, the priority of each wireless power receiver, May be adaptively determined. Here, the power intensity for each wireless power receiver can be determined as to how much power should be received at a ratio of the maximum power that can be processed by the rectifier of the corresponding wireless power receiver.

The wireless power transmitter may then send a predetermined power control command to the wireless power receiver that includes information regarding the determined power strength. At this time, the wireless power receiver can determine whether power control is possible with the power intensity determined by the wireless power transmitter, and transmit the determination result to the wireless power transmitter through the 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 a power control command of the wireless power transmitter before receiving the power control command.

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

In one example, the first state 341 may indicate that the power reception state of all wireless power receivers connected to the wireless power transmitter is in a normal voltage state.

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

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

The wireless power transmitter may transition to the lock fault condition 360 if a system error is detected in the power saving state 320 or the low power state 330 or the power transmission state 340

The wireless power transmitter of the lock fault condition 360 may transition to either a configuration state 310 or a power saving state 320 if all connected wireless power receivers are determined to have been removed from the charging area.

In addition, in the lock fault condition 360, the wireless power transmitter may transition to the local fault condition 350 if a local fault is detected. Here, the wireless power transmitter, which is the local fault condition 350, may transition back to the lock fault condition 360 once the local fault is released.

On the other hand, when transitioning from a state of either configuration state 310, power saving state 320, low power state 330, or power transfer state 340 to local fault state 350, If it is released, it may transition to the configuration state 310.

The wireless power transmitter may shut off the power supplied to the wireless power transmitter if it transitions to the local failure state 350. [ For example, the wireless power transmitter may transition to a local fault condition 350 when a fault such as overvoltage, overcurrent, or overtemperature is detected, but is not limited thereto.

For example, the wireless power transmitter may transmit a predetermined power control command to the connected at least one wireless power receiver to reduce the strength of the power received by the wireless power receiver, if an over-current, over-voltage,

In another example, the wireless power transmitter may send a predetermined control command to the connected at least one wireless power receiver to stop the charging of the wireless power receiver if an overcurrent, overvoltage, overheating, or the like is sensed.

Through the above-described power control procedure, the wireless power transmitter can prevent the device from being damaged due to overvoltage, overcurrent, overheat or the like.

The wireless power transmitter may transition to the lock fault condition 360 if the intensity of the output current of the transmit resonator is above a reference value. At this time, the wireless power transmitter which has transitioned to the lock failure state 360 may attempt to make the intensity of the output current of the transmission resonator less than 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 repeated execution, the wireless power transmitter transmits a predetermined notification signal to the user indicating that the lock failure state 360 is not released using a predetermined notification means can do. At this time, if all of the wireless power receivers located in the charging area of the wireless power transmitter are removed from the charging area by the user, the locking failure state 360 may be released.

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

The wireless power transmitter in the power transfer state 340 can transmit continuous power and adaptively control the transmit power based on the state information of the wireless power receiver and the predefined optimal voltage region setting parameters have.

For example, the Optimal Voltage Region setting parameter may include at least one of a parameter for identifying the low voltage region, a parameter for identifying the optimum voltage region, a parameter for identifying the high voltage region, and a parameter for identifying the overvoltage region .

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

The wireless power transmitter may also control the transmit power to maximize the power transmission efficiency.

The wireless power transmitter may also control the transmit power so that the deviation of the amount of power required by the wireless power receiver is below a reference value.

The wireless power transmitter may also stop transmitting power when the rectifier output voltage of the wireless power receiver reaches a predetermined overvoltage range-that is, when Over Voltage is detected.

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

4, the state of the wireless power receiver is largely divided 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).

At this time, the state of the wireless power receiver may be determined based on the intensity of the output voltage at the rectifier end of the wireless power receiver - hereinafter referred to as V _RECT for convenience of explanation.

The activation state 430 may be divided into an optimum voltage state 431, a low voltage state 432, and a high voltage state 433 depending on the value of V _RECT .

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

In the boot state 420, the wireless power receiver establishes an out-of-band communication link with the wireless power transmitter and transmits a V _RECT And wait until the value reaches the required power at the lower end.

The wireless power receiver in the boot state 420 is a V _RECT When it is confirmed that the required power at the lower end has been reached, the charging state can be shifted to the activated state 430 to start charging.

The wireless power receiver in the active state 430 may transition to the boot state 420 if it is confirmed that charging is complete or charging is interrupted.

In addition, the wireless power receiver in the active state 430 may transition to a system error state 440 if a certain system error is detected. Here, system faults may include overvoltage, overcurrent, and overheating, as well as other predefined system fault conditions.

In addition, the wireless power receiver in the active state 430 is a V _RECT If the value falls below the V _{RECT _BOOT} value, it may transition to the 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 active state 430 will be described in detail with reference to FIG. 5, which will be described later.

5 is a view for explaining an operation region of a wireless power receiver of an electromagnetic resonance type according to a VRECT according to an embodiment of the present invention.

Referring to Figure 5, the V _RECT value is smaller than a predetermined V _{RECT _ BOOT,} the wireless power receiver is held in the inactive state (410).

When Thereafter, V _RECT value is increased above V _{RECT _BOOT,} the wireless power receiver and changes to the boot state 420, it is possible to broadcast the advertisement signal within the prescribed time. Thereafter, if the ad signal is detected by the wireless power transmitter, the wireless power transmitter may transmit a predetermined connection request signal for setting the 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.

When V _RECT value exceeds V _{RECT _MIN,} status of the wireless power receiver and transitions to the active state 430, the boot state 420 may begin charging the load.

If, when the value V _RECT in active state (430) exceeds the predetermined threshold value of V _{RECT _MAX} for determining an over-voltage, the wireless power receiver is in the active state 430 may transition to a system error condition (440).

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

Low voltage 532 _{V RECT _BOOT <= V RECT <} = V RECT _ means the _MIN state, and the optimum voltage state 531 means a state of V _{RECT _MIN} <V _RECT <= V _{RECT _ HIGH,} a high voltage state 533 may indicate the state _{RECT_HIGH} V <V _RECT <= V _{RECT _ MAX.}

In particular, the wireless power receiver transited to the high voltage state 533 may suspend the operation of shutting off the power supplied to the load for a predetermined time - called a high voltage state holding time for convenience of explanation. At this time, the high-voltage state holding time can be predetermined so as to prevent damage to the wireless power receiver and the load in the high-voltage state (533).

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

 The wireless power receiver may also control the voltage applied to the load using overvoltage shutdown means provided to prevent damage to the load due to the overvoltage in the system fault state 530. [ Here, an ON / OFF switch and / or a zener diode may be used as the overvoltage shutoff means.

Although a method and means for responding to a system error in a wireless power receiver have been described in the above embodiment when an overvoltage is generated in a wireless power receiver and transition to a system error state 540 is made, Other embodiments may also transition to a system fault state by overheating, overcurrent, and the like in the wireless power receiver.

As an example, if the system transitions to a system fault state due to overheating, the wireless power receiver may send a message to the wireless power transmitter indicating the occurrence of overheating. At this time, the wireless power receiver may drive a cooling fan or the like to reduce internally generated heat.

A 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 a system error state 540 if it is determined that the wireless power transmitter that is determined to receive the actual wireless power is different from the wireless power transmitter where the actual out-of-band communication link is established.

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

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

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

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

When the wireless power transmitter receives the advertisement signal, it may transmit a predetermined connection request signal to the wireless power receiver to establish an out-of-band communication link (S605).

Upon receipt of the connection request signal, the wireless power receiver may establish an out-of-band communication link and transmit its static status information over the established out-of-band communication link (S607).

Here, the static state information of the wireless power receiver includes category information, hardware and software version information, maximum rectifier output power information, initial reference parameter information for power control, information on demand voltage or power, Information about a supportable out-of-band communication method, information about a supportable power control algorithm, and preferred rectifier voltage value information initially set in the wireless power receiver.

The wireless power transmitter may transmit the static state information of the wireless power transmitter to the wireless power receiver via the out-of-band communication link when the static state information of the wireless power receiver is received (S609).

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

Thereafter, the wireless power receiver monitors its own real-time power receiving state and charging state, and may transmit dynamic state information to the wireless power transmitter at 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 measured temperature of the wireless power receiver, reference parameter change information A rectified voltage minimum value, a rectified voltage maximum value, and an initially set preferred rectifier terminal voltage change value), charging state information, system error information, and alarm information. The wireless power transmitter may perform power adjustment by changing a set value included in the existing static state information when receiving the reference parameter change information for the power control.

In addition, the wireless power transmitter may send a predetermined control command over the out-of-band communication link to control the wireless power receiver to start charging when sufficient power is available to charge the wireless power receiver (S613).

The wireless power transmitter may then receive dynamic state information from the wireless power receiver and dynamically control the transmit power (S615).

The wireless power receiver may also transmit to the wireless power transmitter data to identify the system error in the dynamic state information and / or data indicating that charging is complete if an internal system error is detected or the charging is completed S617). Here, the system error may include overcurrent, overvoltage, overheating, and the like.

The wireless power transmitter according to another embodiment of the present invention redistributes the power to be transmitted to each wireless power receiver when it can not meet the required power of all the wireless power receivers to which the available power is connected, To the corresponding wireless power receiver.

In addition, if a new wireless power receiver is registered during wireless charging, the wireless power transmitter redistributes the power to be received per connected wireless power receiver based on the current available power and transmits it to the corresponding wireless power receiver through a predetermined control command It might

In addition, the wireless power transmitter may be configured such that when the charging of an existing connected wireless power receiver during wireless charging is completed or the out-of-band communication link is released-for example, when the wireless power receiver is removed from the charging area- It may redistribute the power to be received by the wireless power receiver and transmit it to the corresponding wireless power receiver through a predetermined control command.

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

In one example, the power redistribution situation may include receiving a valid advertisement signal from an unconnected wireless power receiver to receive a dynamic parameter indicating a new wireless power receiver's current state or the like of a connected wireless power receiver, This may occur if an event such as no longer exists or an already connected wireless power receiver has been charged, or an alarm message is received indicating a system error condition of the connected wireless power receiver has occurred have.

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

In one example, the wireless power transmitter may transmit power redistribution related information to a wireless power receiver via a predetermined control command.

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

As an example, the wireless power transmitter can determine whether a new wireless power receiver is registered and can provide the amount of power required by the wireless power receiver based on its available power. As a result of the determination, if the requested amount of power exceeds the amount of available power, the wireless power transmitter can confirm whether or not the power control function is mounted on the corresponding wireless power receiver. As a result, if the power control function is implemented, the wireless power receiver may determine the amount of power that the wireless power receiver will receive within the available power amount 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 within a range in which normal charging is possible.

A wireless power receiver according to another embodiment of the present invention can support a plurality of out-of-band communication methods. If the currently set out-of-band communication link is to be changed in a different manner, the wireless power receiver may send a predetermined control signal to the wireless power transmitter requesting an out-of-band communication change. When the out-of-band communication change request signal is received, the wireless power transmitter can release the currently set out-of-band communication link and establish a new out-of-band communication link in the out-of-band communication mode requested by the wireless power receiver.

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

Hereinafter, a method of switching the charging mode from the electromagnetic induction method to the electromagnetic resonance method based on the electromagnetic resonance method described above will be described with reference to FIGS. 7 to 10. FIG. However, a multimode wireless power transmission scheme supporting both the electromagnetic resonance mode and the electromagnetic induction mode will be described first.

A wireless power transmitter (hereinafter referred to as "MMTx "), which supports a multimode wireless power transmission scheme, is a wireless power receiver that operates in either one of an electromagnetic induction mode and an electromagnetic resonance mode. (hereinafter referred to as " MMRx ") capable of transmitting power to a single mode WPT Tx device (hereinafter referred to as" SMTx ") and supporting a multimode wireless power transmission method. May also receive power from a single mode WPT Rx device (hereinafter referred to as "SMRx ") that operates in either the electromagnetic induction mode or the electromagnetic resonance mode.

The MMTx supporting the electromagnetic induction method and the electromagnetic resonance method can be applied to a type 1 wireless power transmitter (hereinafter referred to as "Tier 1 MMTx") capable of simultaneously supporting the above two methods, And a second type wireless power transmitter (hereinafter referred to as "Tier 2 MMTx").

Tier 1 MMTx can simultaneously deliver power by electromagnetic induction and electromagnetic resonance. To perform both methods, Tier 1 MMTx can perform the detection procedure corresponding to each mode. For example, Tier 1 MMTx can detect MMRx or SMRx using electromagnetic induction analog ping and electromagnetic resonance short beacon. Tier 1 MMTx can be performed by arranging the detection procedure corresponding to each of these modes in time.

When the Tier 1 MMTx detects the presence of SMRx (a wireless power receiver supporting an electromagnetic induction scheme or a wireless power receiver supporting an electromagnetic resonance scheme), the above detection procedure is stopped and the corresponding wireless power transmission scheme corresponding to the first detected wireless power transmission scheme And complete a communication session setup for performing wireless power transmission.

However, if the Tier 1 MMTx detects the presence of the MMRx capable of supporting both schemes, the detection procedure of the wireless power transmission scheme other than the first detected wireless power transmission scheme can be continued.

The Tier 1 MMTx can be performed by arranging the detection procedure corresponding to each mode in time if the communication session establishment for performing the wireless power transmission with SMRx or MMTx is not completed.

If the Tier 1 MMTx is attempting to establish a communication session to perform a wireless power transmission using another wireless power transmission scheme while the MMRx is transmitting power in any one of the wireless power transmission schemes, The MMTx can terminate the Tier 2 MMRx wireless power transfer session setup by a predefined process.

Tier 1 MMTx may receive a signal (multimode advertising, MMA) to retrieve a wireless power transmitter from MMRx or SMRx.

Multimode advertising (MMA) can be used to search for wireless power transmission transmitters / receivers that can operate in electromagnetic induction and / or electromagnetic induction. In other words, the MMA performed by the power transmission unit (PTU) applied to the electromagnetic resonance communication can utilize the characteristics defined by the electromagnetic induction method.

Tier 2 MMTx can transmit power only at one time either electromagnetic induction or electromagnetic resonance. In order to perform only one of the two methods, Tier 2 MMTx uses either frequency at one time The power signal can be applied to the coil.

Tier 2 If the MMTx is not transmitting power to the wireless power receiver, the Tier 2 MMTx can perform two types of detection procedures. Since the detection procedure of the Tier 2 MMTx does not require the continuous operation of the two methods, the detection procedure of each method can be performed by inserting it so as to meet the respective reference request timing.

Tier 2 MMTx can transmit power to the first MMTx or SMTx that has completed the required detection and authentication procedures in either of two ways.

While the Tier 2 MMTx is transmitting power in any one of the wireless power transmission schemes, the Tier 2 MMTx may not attempt detection procedures with other wireless power transmission schemes.

The Tier 2 MMTx can return to the multimode detection procedure when the wireless power transmission is completed as defined in each of the two schemes.

Tier 2 MMTx can also receive multimode advertising (MMA) for searching for wireless power transmitters from MMRx or SMRx.

The Tier 2 MMTx may include a user interface (UI) that can display status for a particular mode of operation at a particular point in time.

MMRx, which supports both electromagnetic induction and electromagnetic resonance, supports both MMTx, which can be selected and performed smoothly without user intervention, as well as SMTx, which supports one wireless power transmission scheme. Can be performed. MMRx is a type 1 wireless power receiver (hereinafter referred to as " Tier 1 MMRx ") capable of simultaneously supporting the above two schemes, and a second type wireless power receiver (hereinafter referred to as" Tier 2 MMRx ").

The Tier 1 MMRx can provide the power required by the system when at least one of the electromagnetic induction method and the electromagnetic resonance method is active.

Tier 2 MMRx may support one method at a time, Tier 2 MMRx may not be subject to damage due to multimode power transmission from a wireless power transmitter, and a multimode power transmission scheme may be implemented in a wireless power transmitter It may not cause damage. However, when the multimode power transmission scheme is performed, there is no need to actively supply power to the load (system).

While in the process of receiving power, MMRx may communicate to the wireless power transmitter using a defined communication protocol in each manner whether it is receiving power in one way or in two ways .

MMRx can perform automatic switching in other ways if it can not properly receive power in either of the two ways currently. MMRx may use a mechanism defined for a particular mode for signal generation to terminate any one of the wireless power transmission schemes and may use a mechanism defined to set the other scheme.

In this case, the wireless power transmitter may be adapted to adaptively transmit the wireless power transmission scheme to be used for the wireless power receiver based on the type, state, required power, etc. 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.

Tier 1 MMRx can perform two types of switching using the "make before break" method so that the power transmission in the Tier 1 MMTx can be performed continuously. If switching fails, MMRx can continue to receive power in the same manner it did before switching.

The Tier 1 MMRx can shorten the time required to perform the direct communication with the new wireless power transmitter and to switch it before terminating the connection with any one wireless power transmitter by the "make before break" scheme.

Tier 1 MMRx or Tier 1 receiving power from Tier 2 MMTx, or Tier 2 MMRx receiving power from Tier 1, 2 MMTx, receiving power from Tier 2 MMTx prior to any other type of setting being switched using the alternate mode, It must be terminated. However, if this attempt fails, MMRx attempts to reconnect to perform the originally performed scheme.

MMRx can perform communication using BLE (Bluetooth Low Energy) defined in the electromagnetic resonance method only when a power carrier within the resonance frequency range is detected.

MMRx can communicate using in band load modulation communication defined in the electromagnetic induction method only when the power carrier is detected in the inductive frequency range defined by the electromagnetic induction method.

7 is a flowchart illustrating an operation of a wireless power transmitter and a wireless power receiver supporting a multimode wireless power transmission scheme according to an embodiment of the present invention.

Referring to FIG. 7, an embodiment of the present invention is a method for switching a wireless power transmission method from an electromagnetic resonance method to an electromagnetic induction method. Therefore, the electromagnetic induction type wireless charging procedure described in FIG. 6 can be used.

When power is applied to the wireless power transmitter 700 (S701), the wireless power transmitter 700 can enter the 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 can apply each type of different power beacons for detection in each cycle. For example, the wireless power transmitter 700 may apply a power beacon for detection (e.g., a short beacon or a long beacon) (S704, S705) The magnitude of the power value of each of the beacons may be different.

Some or all of the power beacons for detection may have an amount of power capable of driving the communication portion of the wireless power receiver 750. [ For example, the wireless power receiver 750 can communicate with the wireless power transmitter 700 by driving a communication unit by some or all of the power beacons for detection. At this time, the state may be referred to as a null state (S706).

The wireless power transmitter 700 may detect a load change due to the placement of the wireless power receiver 750 and may enter a Low Power state after detecting a load change at step S708.

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

The wireless power receiver 750 may transmit a BLE-based Advertisement (AD) signal as a signal to search 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 transmit it until a predetermined time has elapsed.

Also, according to an embodiment of the present invention, the wireless power receiver 750 detects the identification information of the wireless power transmitter 700 included in the beacon signal transmitted from the wireless power transmitter 700, Information may be included in the advertisement signal and transmitted.

When a wireless power transmitter search signal is received from the wireless power receiver 750, the wireless power transmitter 700 may transmit a response signal (PRU Response) signal (S711). Where 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 established, the wireless power receiver 750 may transmit the PRU static signal (S712). Here, the PRU static signal may be a signal indicating the status of the wireless power receiver 750 and may request a subscription to the wireless power network controlled by the wireless power transmitter 400.

The wireless power receiver 750 may transmit a PRU Inductive (Multimode) Characteristic signal while transmitting the PRU static signal to the wireless power transmitter 700 (S713). The PRU static signal may include state information of the wireless power receiver 750 to perform the electromagnetic resonance method, while the PRU inductive (Multimode) characteristic signal may include a state in which the wireless power receiver 750 supports the electromagnetic induction method Information. The wireless power transmitter 700 may receive the PRU Inductive (Multimode) Characteristic signal to verify that the wireless power receiver 450 is a wireless power receiver (MMRx) of the multimode wireless power transmission scheme.

In one embodiment, the PRU Inductive (Multimode) Characteristic may have a data structure as shown in Table 2.

The wireless power transmitter 700 may transmit the PTU static signal (S714). The PTU static signal transmitted by the wireless power transmitter 700 may be a signal indicating the capability of the wireless power transmitter 700.

The wireless power transmitter 700 may transmit the PTU static signal to the wireless power receiver 750 and transmit the PTU Inductive (Multimode) Characteristic signal (S715). The wireless power transmitter 700 receives a PRU Inductive (Multimode) Characteristic signal and confirms that the wireless power receiver 750 is a wireless power receiver (MMRx) of a multi-mode wireless power transmission method and transmits a PTU Inductive (Multimode) can do. The PTU Inductive (Multimode) Characteristic signal may include information about the capability of the wireless power transmitter 700 to support the electromagnetic induction scheme. The wireless power receiver 750 may receive the PTU Inductive (Multimode) Characteristic signal to verify that the wireless power transmitter 700 is a wireless power transmitter (MMTx) of the multimode wireless power transmission scheme.

In one embodiment, the PTU Inductive (Multimode) Characteristic may have a data structure as shown in Table 3.

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 (S716, S717) .

The PRU dynamic signal may include at least one parameter information measured at the wireless power receiver 750. For example, the PRU dynamic signal may include voltage information at the rear end of the rectifying section of the wireless power receiver 750. The state of this wireless power receiver 750 may be referred to as a boot state (S707).

The wireless power transmitter 700 enters a power transfer state at step S718 and the wireless power transmitter 700 transmits a PRU control PRU control, which is a command signal to cause the wireless power receiver 750 to perform charging, Signal (S719). In the power transmission state, the wireless power transmitter 700 can transmit the charging power.

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

The wireless power receiver 750 may transmit a wireless power receiver dynamic (PRU Dynamic) signal to change the setting in accordance with the PRU control signal and to report the status of the wireless power receiver 750 (S721, S722 ).

The PRU dynamic signal transmitted by the wireless power receiver 750 may include at least one of voltage, current, state of the wireless power receiver 750, and temperature information. The state of the wireless power receiver 750 may be referred to as an On state. On the other hand, the PRU dynamic signal can have a data structure as shown in Table 4 below.

Referring to Table 4, the PRU dynamic signal may include at least one field. The voltage information at the rear end of the rectifying section of the radio power receiver 750, the current information at the rear end of the rectifying section of the radio power receiver 750, the voltage at the rear end of the DC / DC converter 750 of the radio power receiver 750, Temperature information, the minimum voltage value information (VRECT_MIN_DYN) at the rear end of the rectifying section of the wireless power receiver 750, the current information of the rear end of the DC / DC converter of the wireless power receiver 750, The maximum voltage value information VRECT_HIGH_DYN at the rear end of the rectifying section of the wireless power receiver 750 and the warning information PRU alert may be set. The PRU dynamic signal may include at least one of the above fields.

For example, at least one voltage set value (e.g., minimum voltage value information (VRECT_MIN_DYN) at the rear end of the rectifying section of the wireless power receiver 750), the optimum value of the rear end of the rectifying section of the wireless power receiver 750 Voltage value information (VRECT_SET_DYN), maximum voltage value information (VRECT_HIGH_DYN) at the rear end of the rectifying section of the wireless power receiver, etc.) in the corresponding field of the PRU dynamic signal. In this manner, the wireless power transmitter 700 receiving the PRU dynamic signal can adjust the wireless charging voltage to be transmitted to each wireless power receiver 750 by referring to the voltage setting values included in the PRU dynamic signal.

Among them, the warning information (PRU Alert) can be formed with the data structure as shown in Table 5 below.

Referring to Table 5, the warning information includes overvoltage, overcurrent, over temperature, wireless power receiver 750 PRU Self Protection, charge complete, A Wired Charge Detect, a wireless power receiver 75 PRU Charge Port, and an Adjust Power Response.

If a '1' is set in the overvoltage field, this may indicate that the voltage Vrect at the wireless power receiver 750 has exceeded the overvoltage limit. In addition, over current and over temperature can be set in the same manner as in overvoltage. Also, the wireless power receiver 750 self protection (PRU Self Protection) means that the wireless power receiver 750 protects by reducing the power directly on the load, in which case the wireless power transmitter 700 can change the state of charge no need. The wireless power receiver 75 PRU Charge Port may be set to "1" to indicate that the port output for wireless power transmission of the wireless power receiver 75 is activated. Adjust Power Response is used to indicate whether the wireless power receiver 750 has adjusted its output power (PRECT) in response to a power adjustment command. For example, when the wireless power receiver 750 adjusts the output power according to the power adjustment command of the wireless power transmitter 700, the Adjust Power Response bit may be set to "1 & It may receive an adjustment command and adjust the output power (PRECT) within a few seconds (e.g., one second).

On the other hand, the alert information (PRU Alert) may be included in the PRU dynamic signal but may also be included in the PRU alert characteristic signal.

The PRU alert characteristic signal can be formed with the data structure as shown in Table 6. [

Referring to Table 6, the PRU alert characteristic signal may largely include warning information (PRU Alert) and a device address (receiver address) of the wireless power receiver 750. The warning information (PRU Alert) of the PRU alert characteristic signal differs from the last two bits of the PRU dynamic signal and can be formed by the data structure as shown in Table 7. [

Referring to Table 7, the warning information includes overvoltage, overcurrent, over temperature, wireless power receiver 750 PRU Self Protection, charge complete, Wired Charge Detect, Mode Transition, and the like.

Here, over voltage, over current, over temperature, wireless power receiver 750 PRU Self Protection, charge complete, wired charge detector, Can exhibit the same characteristics as the PRU dynamic signal.

The bits for Mode Transition according to the embodiment of the present invention may be set to a value for notifying the wireless power transmitter 700 of a period during which the mode switching procedure is performed.

In one embodiment of mode transition, when the wireless power receiver 750 is in an On state and the wireless power transmitter 700 is in a Power Transfer State, the wireless power receiver 750 May perform a power transfer mode switching process to power other subsystems of the platform in which the wireless power receiver 750 is included.

The bit indicating the mode switching period can be expressed as shown in Table 8 below.

Referring to Table 8, the wireless power transmitter 700 sets the bits (01, 10, 11) corresponding to the time required for performing the mode switching as shown in Table 5. '00' indicates no mode change, '01' indicates that the time required to complete the mode change is at most 2 seconds, '10' indicates that the time required to complete the mode change is at most 3 seconds , And '11' may indicate that the time required to complete the mode change is at most 6 seconds.

For example, if it takes 3 seconds or less to complete the mode change, the mode change bit may be set to '10'. Prior to the start of this mode switching procedure, the wireless power receiver 750 may change the input impedance setting to fit a 1.1 W power draw to limit any impedance changes during the mode switching procedure. Accordingly, the wireless power transmitter 700 adjusts the power (ITX_COIL) for the wireless power receiver 750 to match this setting, and thus maintains the power (ITX_COIL) for the wireless power receiver 750 during the mode transition period have.

Thus, if a mode transition period is set by the mode change bit, the wireless power transmitter 700 can maintain the power ITX_COIL for the wireless power receiver 750 for that mode transition time (e.g., 3 seconds). That is, the connection can be maintained even if no response is received from the wireless power receiver 750 for three seconds.

However, after the mode switching time has elapsed, the wireless power receiver 750 may be regarded as a rouge object and the power transmission may be terminated.

The power transfer mode switching process may boil the previously connected BLE communication between the wireless power receiver 750 and the wireless power transmitter 700 and reinitialize for a new BLE communication connection may be performed. The Device Address (receiver address) of the wireless power receiver 750 included in the PRU alert characteristic signal can be used to connect the new BLE communication.

In particular, the wireless power receiver 750 may inform the wireless power transmitter 700 of the intent to terminate the BLE communication between the wireless power transmitters 700 through the GAP Termination Connection Procedure. At this time, the mode transition notification of the wireless power receiver 750 indicates that the received wireless power transmitter 700 stops the physical BLE communication with the wireless power receiver 750 and then transmits the GATE Can be performed.

The wireless power receiver 750 sets the BLE Device address to connect the new BLE communication using the device address included in the PRU alert characteristic signal, and sets all zero if the device address for the mode transition is unknown Can be set.

If the set time is less than or equal to 3 seconds, the wireless power transmitter 700 waits for the time to reconnect to the wireless power receiver 750 while maintaining ITX_COIL. If the set time is greater than 3 seconds, the wireless power transmitter 700 must set the input impedance to meet the requirements for the wireless power transmitter 700 to enter the boot state (P_RECT_BOOT <1.1W, etc.) The wireless power transmitter 700 must maintain and maintain ITX_COIL. The PRU registration can be deleted at the time of re-connection within that time.

Meanwhile, the wireless power receiver can switch the wireless power transmission scheme using the mode switching table of Table 6. [

In one embodiment, the wireless power receiver may switch the wireless power transmission scheme in an electromagnetic induction manner in an electromagnetic resonance mode using the mode transition table of Table 4. [

The wireless power receiver can switch the wireless power transmission scheme using PRU self-protection field information, PRU characteristic information and Mode transition bit of the warning information (PRU Alert).

In one embodiment, when the PRU characteristic information received from the wireless power receiver is MMRx supporting the multi-mode, the PRU self-protection bit value is "1" and the mode transition information is non-zero (a value other than "00" , The wireless power transmitter may perform an agreed upon operation between the wireless power transceivers to switch the wireless power transmission scheme from electromagnetic resonance to electromagnetic induction.

In addition, bits for mode transition according to an embodiment of the present invention can be expressed as shown in Table 9. [

Referring to Table 9, when the bit value for mode switching is "01" or "10 ", the wireless power transmitter 700 transmits an electromagnetic induction method (or electromagnetic induction method) Electromagnetic resonance mode).

In one embodiment, when the mode transition field received from the wireless power receiver is 01, it is set to perform multi-mode switching and the wireless power transmitter 700 can receive an Alert bit with a Mode transition field of 01 .

If the wireless power receiver is a Tier 1 MMRx and the wireless power transmitter 700 is a Tier 1 MMTx, then I_tx_coil is maintained and a ping (Alter mode pinging) signal is waited for a predetermined time for a communication connection to perform the electromagnetic induction scheme , And can ignore the mode transition request received from the Tier 1 MMRx if it does not receive the ping signal for a preset time.

If the wireless power receiver is a Tier 2 MMRx or Tier 2 MMtx and the wireless power transmitter 700 is, the existing I_tx_coil can be set to zero to receive ping (alter mode pinging). Thereafter, the wireless power transmitter 700 may apply a constant current to the coil to transmit the long beacon in the boot state. After transmitting the long beacon, it can be confirmed whether it receives additional signals from the wireless power receiver.

Meanwhile, the wireless power receiver 750 may sense an error occurrence. The wireless power receiver 750 may send an alert signal to the wireless power transmitter 700 (S723). The warning signal can be transmitted as a PRU Dynamic (PRU Dynamic) signal or as an alert signal. For example, the wireless power receiver 750 may reflect the error condition in the PRU alert field of Table 5 and transmit it to the wireless power transmitter 700. Or wireless power receiver 750 may send a single alert signal to wireless power transmitter 700 indicating an error condition. Upon receiving the warning signal, the wireless power transmitter 700 may enter the Latch Fault mode (S724). The wireless power receiver 750 may enter a null state (S725).

8 is a flowchart illustrating an operation of a wireless power receiver supporting a multimode wireless power transmission scheme according to an embodiment of the present invention.

Referring to FIG. 8, a wireless power receiver receives a PTU static signal from a wireless power transmitter to receive power in an electromagnetic resonance manner (S810). The PTU static signal may include power capability information according to the electromagnetic resonance method of the wireless power transmitter. The wireless power transmitter can transmit the PTU static signal when it is in a low power state and can transmit the static state information of the wireless power transmitter at a constant cycle even in a power transfer state.

The wireless power receiver calculates the reception efficiency using the capability information of the wireless power transmitter included in the PTU static signal and the parameters measured internally (S820). The parameters measured inside the wireless power receiver may include parameters indicating internal voltages, currents, temperatures, and the like.

For example, the parameters measured in the interior of the wireless power receiver may be the minimum voltage (V), V_rect, V_uvlo, etc. of the rectification section (e.g., DC-DC converter)

For example, the wireless power receiver may request transmission mode switching when the voltage value V_rect of the rectifier is lower than the rectifier minimum required voltage V_rect_set_min for a predetermined period of time (S820).

In another embodiment, the wireless power receiver may require switching when the received power is low as compared to the transmitter power or the amount of available power that the transmitter can provide and the voltage and current applied to the receiving coil.

It is assumed that both the transmitter and the receiver support multimode, and whether or not the multimode is supported can be known in step S810 (see Table 2 and Table 3).

The wireless power receiver uses a PRU alert field with the wireless power transmitter when the reception efficiency is lower than the switching threshold (the reception efficiency is low, and the method of determining the reception efficiency can be variously applied) It may request the wireless power transmission mode switching (S830).

The reception efficiency can be calculated using the parameters measured in the wireless power receiver and the power information of the wireless power transmitter included in the PTU static signal.

In one embodiment, the wireless power receiver is configured such that the minimum voltage (V), V_rect, and V_uvlo of the rectification section (e.g., DC-DC converter) included in the wireless power receiver is greater than a preset threshold value for switching the wireless power transmission scheme If it is low, it can request the wireless power transmission mode switching.

When the wireless power receiver receives the switching permission message from the wireless power transmitter, the wireless power transmission mode is switched (S840).

The wireless power receiver may request the switching of the wireless power transmission scheme to the wireless power transmitter and then stop transmitting the existing dynamic state information to receive power in the wireless power transmission scheme to be switched.

For example, when the existing first wireless power transmission system is an electromagnetic resonance system and the second wireless power transmission system to be switched is an electromagnetic induction system, the wireless power receiver transmits a PRU dynamic signal transmitted for a predetermined period .

9 is a flowchart illustrating an operation of a wireless power transmitter supporting a multimode wireless power transmission scheme according to an embodiment of the present invention.

Referring to FIG. 9, the wireless power transmitter transmits a PTU static signal including capability information on power transmission to a wireless power receiver (S910).

The wireless power transmitter receives a PRU alert characteristic signal requesting switching of a wireless power transmission scheme from a wireless power receiver (PRU) (S920).

The wireless power transmitter determines whether to switch the wireless power transmission scheme according to a PRU alert field included in the PRU alert characteristic signal (S930). The wireless power transmitter determines whether or not the switching request of the wireless power transmission scheme is requested according to the mode transition bit of the warning field.

The wireless power transmitter can make the switching decision immediately if the Mode Transition bit is a predetermined value. Alternatively, the wireless power transmitter can determine whether to switch by a combination of bits for indicating operations incompatible with switching operations such as Over-Voltage, Over-Current, and Self-Protection bits included in the PRU alert characteristic in addition to the mode switching bits have.

Mode transition and over voltage, over current, over temperature, wireless power receiver self protection, charge complete, wired charging of wireless power receiver, Signals that warn the Wired Charger Detect are not logically compatible.

For example, PRU Self Protection is incompatible with mode switching because it directs the wireless power receiver to reduce power to the direct load without changing the charging state of the wireless power transmitter. Accordingly, the wireless power transmitter can recognize that the self-protection and mode switching are included in the same alert field (PRU alert field) to request switching of the wireless power transmission scheme. Specifically, when the wireless power transmitter is set to '1' in the PRU Self Protection field and set to '01' in the mode transition bit, it is recognized that the wireless power transmitter requests switching of the wireless power transmission mode can do

As another example, if the wireless power transmitter has at least one of over current, over temperature, charge complete, bit indicating the wired charge detection, Bit is received in the same alert field (PRU alert field), it can be recognized that the switching of the wireless power transmission scheme is requested. The wireless power transmitter transmits the switching permission message to the wireless power receiver while performing the wireless power transmission mode switching according to the switching decision (S940, S950). The wireless power transmitter may transmit permission / denial to the wireless power receiver via PRU control (with permission for mode switching or deny). The PRU control signal can have the data structure as shown in Table 10 below.

Referring to Table 10, the PRU control signal may include information enabling / disabling charging of the wireless power receiver, permission information, and the like. The permission information included in the PRU control signal may indicate not only the permission for the mode change but also the permission for the switching request of the wireless power transmission scheme. In detail, the permission information may have a data structure as shown in Table 11.

Referring to Table 11, the wireless power transmitter can indicate "0000 0010" to allow the switching without a reason, and "0000 0011" to indicate permission after waiting time for power limitation. At this time, the wireless power transmitter can send a "0000 0010" signal again after the wireless power transmitter has performed the power limit and the waiting time has elapsed. The power transmission efficiency, the connection state, the PRU dynamic state of the connected wireless power receiver, and the power consumption of the connected wireless power receiver can be used for reasons other than denying the switching request of the wireless power transmission scheme. Another connected wireless power receiver (other PRU) or the like may be set.

The wireless power transmitter can perform switching while controlling the current (I _{TX - COIL} ) applied to the coil. At this time, when the wireless power transmitter can simultaneously perform the power transmission by the existing first wireless power transmission scheme and the second wireless power transmission scheme to be switched, the current I _{TX_COIL} can be adjusted to a predetermined current. Alternatively, when the wireless power transmitter can not simultaneously perform power transmission by the first wireless power transmission scheme and the second wireless power transmission scheme, the current (I _{TX - COIL} ) is cut off and the power by the second wireless power transmission scheme It may attempt to connect a communication session for transmission.

10 is a flowchart illustrating operations of a wireless power transmitter and a wireless power receiver supporting a multimode wireless power transmission scheme according to an embodiment of the present invention.

Referring to FIG. 10, the conventional wireless power transmission method may be an electromagnetic resonance method and the new wireless power transmission method may be an electromagnetic induction method.

After determining the received power efficiency of the wireless power receiver, the wireless power transmitter may request switching of the wireless power transmission scheme (S1010).

The wireless power receiver may request switching of the wireless power transmission scheme to the wireless power transmitter if the efficiency of the power received from the wireless power transmitter is lower than a preset efficiency.

For example, if the output value of the received DC-DC converter is less than a predetermined value (minimum V) and / or the V_rect value is less than a predetermined value (V_uvlo) according to the electromagnetic induction method, It is possible to request switching to the wireless power transmitter in an electromagnetic-known manner.

At this time, the wireless power receiver may request switching of the wireless power transmission scheme through a specific message (e.g., PRU Alert characteristic signal). The PRU Alert characteristic signal may be a signal differentiated from the PRU Dynamic characteristic that the wireless power receiver transmits to the wireless power transmitter at regular intervals.

In one embodiment, the wireless power receiver may request switching using the PRU Alert Filed included in the PRU Dynamic characteristic signal.

The wireless power transmitter may determine whether to perform the switching using the status information of the wireless power receiver (S1020).

The wireless power transmitter may permit switching based on the current state of the wireless power transmitter itself, the connection state with another wireless power receiver, or the state information received from the wireless power receiver, the property information.

In one embodiment, the wireless power transmitter may receive the Alert bit from the wireless power receiver and perform switching immediately after a certain period of time. In this case, the retry interval may increase every time the switching attempt fails.

Thereafter, the wireless power transmitter may transmit permission / denial to the wireless power receiver via PRU control (with permission for mode switching or deny).

When the wireless power transmitter transmits the request to the permission signal wireless power receiver in response to the switching request, the wireless power transmitter controls the electric current applied to the coil to control the power to be transmitted (S1030).

The wireless power transmitter performs an authentication procedure to perform a wireless power transmission scheme different from the existing wireless power transmission scheme while interrupting the power transmitted to the wireless power receiver (Tier 2 MMTx) or adjusting or maintaining the power (Tier 1 MMTx) (S1040).

The wireless power transmitter transmits a ping (Alternative mode analog ping / digital ping) signal for performing an electromagnetic induction method, which is a new wireless power transmission mode (Alternative mode) switched within a predetermined time, to the wireless power receiver and performs an authentication procedure can do.

Tier 1 MMTx can simultaneously transmit power by electromagnetic induction method and electromagnetic resonance method. Therefore, if the wireless power transmitter is Tier 1 MMTx, it transmits periodically a ping signal even in the state of power transfer by electromagnetic resonance method (Power transfer state) .

At this time, the resonant module of the Tier 1 MMRx may be in the null state (only the BLE communication is connected), and the Tier 2 MMRX may be in the state before the boot state.

The wireless power receiver can transmit the signal to receive the power by the electromagnetic induction method when the reception efficiency of the alternative mode is sufficient by the analog ping / digital ping.

In one embodiment, the wireless power receiver may transmit the received strength packet to the inductive module when the output value of the DC-DC converter is greater than a predetermined value (minimum V).

The wireless power receiver can determine whether to maintain the Alternative mode based on the received power information while receiving the power continuously (PowerTransfer state), and if the efficiency of the received power is lower than a certain value by the electromagnetic induction method, (S1050).

If the wireless power receiver maintains the Alternative mode, it may not send the PRU dynamic characteristic to the wireless power transmitter within a fixed time (e.g., 5 sec). That is, if the wireless power transmitter fails to receive the PRU dynamic characteristic (PRU dynamic signal) within a predetermined time, it can determine that the wireless power receiver has switched to the alternative mode. In addition, when the PRU dynamic characteristic is received, it is possible to control the operation of the alternative mode (ping, identification / setting, power transmission, etc.) to be stopped.

If the wireless power receiver does not maintain the Alternative mode, it can receive the power in the conventional mode by sending the PRU dynamic characteristic to the wireless power transmitter. At this time, if the wireless power receiver is Tier 2 MMRX, the Advertisement can be sent again when the BLE connection is disconnected. In this case, the device address of the PRU Alert is sent equal to the address before Mode Switching, so that it is possible to perform quick reconnection and reception of the existing power.

If the wireless power transmitter fails to receive the PRU Dynamic characteristic within a predetermined time, or if it fails to receive the same device address, it can be determined that switching has been performed and the communication session by the electromagnetic resonance method can be stopped.

Of course, if the wireless power transmitter receives the PRU Dynamic characteristic, the existing transmission power can be maintained.

The method according to the above-described embodiments may be implemented as a program to be executed by a computer and stored in a computer-readable recording medium. Examples of the computer-readable recording medium include a ROM, a RAM, a CD- , A floppy disk, an optical data storage device, and the like, and may also be implemented in the form of a carrier wave (for example, transmission over the Internet).

The computer readable recording medium may be distributed over a networked computer system so that computer readable code can be stored and executed in a distributed manner. And, functional program, code, and code segments for implementing the above-described method can be easily inferred by programmers in the technical field to which the embodiment belongs.

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 or essential characteristics thereof.

Accordingly, the above description should not be construed in a limiting sense in all respects and should be considered illustrative. The scope of the present invention should be determined by rational interpretation of the appended claims, and all changes within the scope of equivalents of the present invention are included in the scope of the present invention.

100: Wireless power transmitter
110: Power supply
120: Power conversion section
130: matching circuit
140: transmitting resonator
150:
160:
200: Wireless power receiver
210: receiving resonator
220: Rectifier
230: DC-DC converter
240: Load
250: main control unit
260:
201: matching circuit
202: Transmission resonator coil
203: Receiver resonator coil
204: matching circuit
211: L1
212: L2

Claims (31)

A method for switching a wireless power transmission mode in a wireless power receiver,
Calculating reception efficiency using at least one parameter measured in the capability information of a wireless PTU (Power Transmission Unit) included in the PTU static signal;
Requesting switching from a first wireless power transmission scheme to a second wireless power scheme using a PRU alert field to the wireless power transmitter if the reception efficiency is lower than a switching threshold; And
Upon receiving a switching grant message from the wireless power transmitter, changing the setting to the second wireless power transmission scheme;
/ RTI &gt;
Wireless power transmission mode switching method. The method according to claim 1,
Wherein the step of requesting switching comprises:
Requesting switching from the first wireless power transmission scheme to the second wireless power scheme using a mode transition bit of the PRU alert field included in the PRU alert characteristic signal;
/ RTI &gt;
Wireless power transmission mode switching method. The method according to claim 1,
The step of calculating the reception efficiency includes:
Calculating reception efficiency using the voltage information and current information measured in the interior;
/ RTI &gt;
Wireless power transmission mode switching method. The method according to claim 1,
Wherein changing the setting to the second wireless power transmission scheme comprises:
When a communication connection for power transmission is not performed in the second wireless power transmission mode or a communication connection for power transmission in the second wireless power transmission mode is not performed within a predetermined time, Changing a setting to &lt; RTI ID = 0.0 &gt;
/ RTI &gt;
Wireless power transmission mode switching method. A method for switching a wireless power transmission mode in a wireless power transmitter,
Receiving a PRU alert characteristic signal requesting switching from a first wireless power transmission scheme to a second wireless power transmission scheme from a wireless power receiver (PRU);
Determining whether to switch from the first wireless power transmission scheme to the second wireless power scheme according to a PRU alert field included in the PRU alert characteristic signal; And
Performing switching to the second wireless power transmission scheme according to the determination;
/ RTI &gt;
Wireless power transmission mode switching method. 6. The method of claim 5,
Transmitting a PTU static signal including capability information on power transmission to the wireless power receiver;
&Lt; / RTI &gt;
Wireless power transmission mode switching method. 6. The method of claim 5,
Wherein the performing the switching to the second wireless power transmission scheme according to the determination comprises:
Transmitting a switching grant message to the wireless power receiver;
/ RTI &gt;
Wireless power transmission mode switching method. 6. The method of claim 5,
Wherein the step of determining whether to switch from the first wireless power transmission scheme to the second wireless power scheme according to a PRU alert field included in the PRU alert characteristic signal comprises:
Determining whether to switch from the first wireless power transmission scheme to the second wireless power scheme according to a mode transition bit of the alert field (PRU alert field) included in the PRU alert characteristic signal;
/ RTI &gt;
Wireless power transmission mode switching method. 6. The method of claim 5,
Wherein the step of determining whether to switch from the first wireless power transmission scheme to the second wireless power scheme according to a PRU alert field included in the PRU alert characteristic signal comprises:
Determining whether to switch from the first wireless power transmission scheme to the second wireless power scheme using state information of the wireless power receiver;
/ RTI &gt;
Wireless power transmission mode switching method. 10. The method of claim 9,
Wherein the step of determining whether to switch from the first wireless power transmission scheme to the second wireless power scheme using state information of the wireless power receiver comprises:
Calculating transmission efficiency using at least one of voltage information and current information of the wireless power receiver, and determining whether to switch to the second wireless power transmission scheme according to the transmission efficiency;
/ RTI &gt;
Wireless power transmission mode switching method. 10. The method of claim 9,
The alert field includes a Mode Transition bit and may include over voltage, over current, over temperature, wireless power receiver self protection, charge completion, complete, and a Wired Charge Detect (Wired Charge Detect).
Wireless power transmission mode switching method. 12. The method of claim 11,
Over voltage, over current, over temperature, wireless power receiver self protection, charge complete, and the like, while the bit indicating the mode change is a predetermined value. Determining whether to switch to the second wireless power transmission scheme considering at least one bit indicating a wired charge detection;
/ RTI &gt;
Wireless power transmission mode switching method. 6. The method of claim 5,
Wherein the performing the switching to the second wireless power transmission scheme according to the determination comprises:
_Adjusting a current (I _{TX - COIL} ) applied to a coil included therein to a preset current;
/ RTI &gt;
Wireless power transmission mode switching method. 14. The method of claim 13,
The step of adjusting the current (I _{TX - COIL} ) applied to the coil included therein to a predetermined current may include:
_Adjusting the current (I _{TX - COIL} ) to a preset current if the first wireless power transmission scheme and the second wireless power transmission scheme can be performed simultaneously;
Blocking and adjusting the current (I _{TX - COIL} ) if the first wireless power transmission scheme and the second wireless power transmission scheme can not be performed at the same time;
/ RTI &gt;
Wireless power transmission mode switching method. 6. The method of claim 5,
Wherein the performing the switching to the second wireless power transmission scheme according to the determination comprises:
A communication connection for power transmission to the wireless power receiver and the second wireless power transmission scheme is not performed or a communication connection for power transmission to the wireless power receiver and the second wireless power transmission scheme is established within a predetermined time If not, performing wireless power transmission in the first wireless power transmission scheme;
/ RTI &gt;
Wireless power transmission mode switching method. A computer-readable recording medium having recorded thereon a program for executing the method according to any one of claims 1 to 15. A communication unit for receiving a PTU static signal including capability information from a wireless power transmission unit (PTU); And
And calculates a reception efficiency using at least one of the capability information and at least one parameter measured internally. If the reception efficiency is lower than a switching threshold value, the wireless power transmitter uses a PRU alert field A controller for requesting switching from a first wireless power transmission scheme to a second wireless power transmission scheme and changing a setting to the second wireless power transmission scheme upon receiving a switching grant message from the wireless power transmitter;
/ RTI &gt;
Wireless Power Receiver (PRU). 18. The method of claim 17,
Wherein,
Requesting switching from the first wireless power transmission scheme to the second wireless power scheme using a mode transition bit of a PRU alert field included in a PRU alert characteristic signal,
Wireless power receiver. 18. The method of claim 17,
Wherein,
And calculating reception efficiency using at least one of the voltage information and the current information measured in the inside,
Wireless power receiver. 18. The method of claim 17,
Wherein,
When a communication connection for power transmission is not performed in the second wireless power transmission mode or a communication connection for power transmission in the second wireless power transmission mode is not performed within a predetermined time, To change the setting,
Wireless power receiver. A communication unit for receiving a PRU alert characteristic signal requesting switching from a first wireless power transmission scheme to a second wireless power transmission scheme from a wireless power receiving unit (PRU); And
Determining whether to switch from the first wireless power transmission scheme to the second wireless power scheme according to a PRU alert field included in the PRU alert characteristic signal, A control unit for performing the switching in the method;
/ RTI &gt;
Wireless Power Transmitter (PTU). 22. The method of claim 21,
Wherein,
Transmitting a PTU static signal including capability information on power transmission to the wireless power receiver,
Wireless power transmitter. 22. The method of claim 21,
Wherein,
Transmitting a switching grant message to the wireless power receiver,
Wireless power transmitter. 22. The method of claim 21,
Wherein,
Determining whether to switch from the first wireless power transmission scheme to the second wireless power scheme according to a mode transition bit of the PRU alert field included in the PRU alert characteristic signal,
Wireless power transmitter. 22. The method of claim 21,
Wherein,
Determining whether to switch from the first wireless power transmission scheme to the second wireless power transmission scheme using state information of the wireless power receiver,
Wireless power transmitter. 26. The method of claim 25,
Wherein,
Calculating transmission efficiency using at least one of voltage information and current information of the wireless power receiver and determining whether to switch to the second wireless power transmission scheme according to the transmission efficiency,
Wireless power transmitter. 26. The method of claim 25,
The alert field includes a Mode Transition bit and may include over voltage, over current, over temperature, wireless power receiver self protection, charge completion, complete, and a Wired Charge Detect (Wired Charge Detect).
Wireless power transmitter. 28. The method of claim 27,
Wherein,
Over voltage, over current, over temperature, wireless power receiver self protection, charge complete, and the like, while the bit indicating the mode change is a predetermined value. Determining whether to switch to the second wireless power transmission scheme considering at least one bit indicating a wired charge detection;
Wireless power transmitter. 22. The method of claim 21,
Wherein,
(I _{TX - & lt} ; RTI ID = 0.0 &gt; _COIL ) &lt; / RTI &gt;
Wireless power transmitter. 22. The method of claim 21,
Wherein,
(I _{TX - - COIL} ) to a predetermined current when the first wireless power transmission scheme and the second wireless power transmission scheme can be performed at the same time,
And controlling the current (I _{TX - COIL} ) when the first wireless power transmission method and the second wireless power transmission method can not be performed at the same time,
Wireless power transmitter. 22. The method of claim 21,
Wherein,
A communication connection for power transmission to the wireless power receiver and the second wireless power transmission scheme is not performed or a communication connection for power transmission to the wireless power receiver and the second wireless power transmission scheme is established within a predetermined time If not, performing wireless power transmission in the first wireless power transmission scheme,
Wireless power transmitter.

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