KR20180001783A - A Wireless power transmitter control method and apparatus including a plurality of coils - Google Patents

Abstract

The present invention relates to a wireless power transmitter control method and apparatus including a plurality of coils. A wireless power transmitter according to an embodiment of the present invention includes: N transmission coils in which at least one of the N coils is superimposed; N switches connecting the N transmit coils and the drive circuit; And a control unit for selecting a transmission coil having the highest power transmission efficiency among the N transmission coils when an object is detected in the charging area and controlling the corresponding switch among N switches connecting the selected transmission coil and the drive circuit; And the conductors constituting each of the N transmit coils may have the same inductance by adjusting their lengths corresponding to respective positions with respect to the shielding material.

Description

TECHNICAL FIELD [0001] The present invention relates to a wireless power transmitter control method and apparatus including a plurality of coils,

The present invention relates to wireless power transmission, and more particularly, to a method and apparatus for controlling a wireless power transmitter including a plurality of coils.

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 be based on a variety of wireless power transmission standards based on an electromagnetic induction scheme in which a magnetic field is generated in a power transmitter coil and charged using an electromagnetic induction principle in which electricity is induced in a receiver coil under the influence of its 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.

On the other hand, the wireless power transmitter may include a plurality of transmit coils. The wireless power transmitter can expand the charging area by using more than one transmitting coil when it includes a single transmitting coil.

Each of the plurality of transmit coils included in the wireless power transmitter can be made to have the same physical characteristics. However, depending on the arrangement of the transmission coil, an area overlapping between the coils may occur, and the inductance may vary depending on the distance from the shielding material that affects the magnetic field generated in the transmission coil.

Therefore, there is a need for a method and apparatus that can utilize the same resonant frequency using a plurality of transmit coils having different inductances from each other.

It is an object of the present invention to provide a method and apparatus for controlling a wireless power transmitter including a plurality of coils.

In order to overcome a limit situation requiring a plurality of identical circuits by using a plurality of transmission coils each having a different inductance, a plurality of transmission coils having the same inductance and using the same resonance frequency using a switch And a method of controlling the wireless power transmitter.

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 an aspect of the present invention, there is provided a method of controlling a wireless power transmitter, the method comprising the steps of: when an object is detected in a charging area, at least one of the N transmission coils Selecting a transmission coil having the highest power transmission efficiency; And controlling the switch among the N switches connecting the selected transmission coil and the drive circuit. And the conductors constituting each of the N transmit coils may have the same inductance by adjusting their lengths corresponding to respective positions with respect to the shielding material.

According to an embodiment, the N transmit coils, each connected in parallel, can be individually activated in series with each of the N switches.

According to an embodiment, the N transmit coils may be connected in series with one capacitor.

According to the embodiment, each of the N transmit coils may have the same inductance by differently turning the coil corresponding to the respective positions with respect to the shielding material.

According to an embodiment, the number of turns of each of the N transmit coils may be different according to the distance from the shielding material.

According to an embodiment, the number of turns of each of the N transmit coils may be increased as the distance from the shielding material increases.

According to an embodiment, the number of turns of each of the N transmit coils may differ from 0.5 to 2 times.

According to an embodiment, the transmit coil may transmit power to the receive coil using a specific resonant frequency.

According to an embodiment, the drive circuit may include an inverter to convert the DC voltage from the power source to an AC voltage.

According to an embodiment, the selected transmit coil may be connected in series between one of the N switches and one of the drive circuits and the capacitor.

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.

Also, a wireless power transmitter according to an embodiment of the present invention includes: N transmitting coils, at least one of which is disposed in a superposed manner; N switches connecting the N transmit coils and the drive circuit; And a control unit for selecting a transmission coil having the highest power transmission efficiency among the N transmission coils when an object is detected in the charging area and controlling the corresponding switch among N switches connecting the selected transmission coil and the drive circuit; And the conductors constituting each of the N transmit coils may have the same inductance by adjusting their lengths corresponding to respective positions with respect to the shielding material.

According to an embodiment, the N transmit coils, each connected in parallel, can be individually activated in series with each of the N switches.

According to an embodiment, the N transmit coils may be connected in series with one capacitor.

According to the embodiment, each of the N transmit coils may have the same inductance by differently turning the coil corresponding to the respective positions with respect to the shielding material.

According to an embodiment, the number of turns of each of the N transmit coils may be different according to the distance from the shielding material.

According to an embodiment, the number of turns of each of the N transmit coils may be increased as the distance from the shielding material increases.

According to an embodiment, the number of turns of each of the N transmit coils may be 0.5 or 1 time difference.

According to an embodiment, the transmit coil may transmit power to the receive coil using a specific resonant frequency.

According to an embodiment, the drive circuit may include an inverter to convert the DC voltage from the power source to an AC voltage.

According to an embodiment, the selected transmit coil may be connected in series between one of the N switches and one of the drive circuits and the capacitor.

Effects of the wireless power transmitter control method and apparatus including a plurality of coils according to the present invention will be described as follows.

First, the present invention can have a wider charging area by using a plurality of transmission coils, thereby improving user convenience.

Secondly, the present invention can use only one of a plurality of identical circuits, thereby reducing the size of the wireless power transmitter itself, reducing the number of parts used, and reducing the cost.

Third, the present invention can utilize the component elements defined in the published wireless power transmission standard, and can follow the already defined 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 wireless charging system according to an embodiment of the present invention.
2 is a block diagram illustrating a wireless charging system according to another embodiment of the present invention.
3 is a diagram for explaining a sensing signal transmission procedure in a wireless charging system according to an embodiment of the present invention.
4 is a state transition diagram for explaining the wireless power transmission procedure defined in the WPC standard.
5 is a state transition diagram for explaining the wireless power transmission procedure defined in the PMA standard.
6 is a block diagram illustrating a structure of a wireless power transmitter according to an embodiment of the present invention.
7 is a diagram for explaining a packet format according to an electromagnetic induction wireless power transmission procedure according to an embodiment of the present invention.
FIG. 8 is a diagram for explaining the types of packets that a wireless power receiving apparatus according to an electromagnetic induction type wireless power transmission procedure according to an embodiment of the present invention can transmit in a ping stage.
9 is a diagram for explaining a message format of an identification packet according to an electromagnetic induction wireless power transmission procedure according to an embodiment of the present invention.
10 is a diagram for explaining a message format of a configuration packet and a power control hold packet according to an electromagnetic induction wireless power transmission procedure according to an embodiment of the present invention.
11 is a diagram for explaining a type of a packet that can be transmitted in a power transmission step and a message format thereof by a wireless power receiving apparatus according to an electromagnetic induction wireless power transmission procedure according to an embodiment of the present invention.
12 is a view for explaining the arrangement of a plurality of transmission coils and the distance from the shielding member according to an embodiment of the present invention.
13 is a view for explaining three drive circuits including a full-bridge inverter in a wireless power transmitter including a plurality of coils according to an embodiment of the present invention.
FIG. 14 is a diagram illustrating a wireless power transmitter including a plurality of coils and including one drive circuit according to an embodiment of the present invention. Referring to FIG.
15 is a view for explaining a drive circuit including a full-bridge inverter according to an embodiment of the present invention.
16 is a diagram for explaining a plurality of switches for connecting any one of a plurality of transmission coils to a drive circuit 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. In particular, the wireless power receiving means for supporting the electromagnetic induction method may include an electromagnetic induction wireless charging technique defined by Wireless Power Consortium (WPC) and Power Matters Alliance (PMA).

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.

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

Referring to FIG. 1, the wireless charging system includes a wireless power transmitter 10 for wirelessly transmitting power, a wireless power receiver 20 for receiving the transmitted power, and an electronic device 20 Lt; / RTI >

For example, the wireless power transmitter 10 and the wireless power receiver 20 may perform in-band communication in which information is exchanged using the same frequency band as that used for wireless power transmission. In another example, the wireless power transmitter 10 and the wireless power receiver 20 may use out-of-band communication to exchange information using a separate frequency band that is different from the operating frequency used for wireless power transmission .

As an example, information exchanged between the wireless power transmitter 10 and the wireless power receiver 20 may include control information as well as status information of each other. Here, the status information and control information exchanged between the transceivers will become more apparent through the description of the embodiments to be described later.

The in-band communication and the out-of-band communication may provide bidirectional communication, but the present invention is not limited thereto. In another embodiment, the in-band communication and the out-of-band communication may be provided.

 In one example, the unidirectional communication may be that the wireless power receiver 20 only transmits information to the wireless power transmitter 10, but the wireless power transmitter 10 is not limited to this, Lt; / RTI >

In the half duplex communication mode, bi-directional communication is possible between the wireless power receiver 20 and the wireless power transmitter 10, but information can be transmitted only by any one device at any time.

The wireless power receiver 20 according to an embodiment of the present invention may acquire various status information of the electronic device 30. [ For example, the status information of the electronic device 30 may include current power usage information, information for identifying a running application, CPU usage information, battery charge status information, battery output voltage / current information, And is information obtainable from the electronic device 30 and available for wireless power control.

In particular, the wireless power transmitter 10 according to an exemplary embodiment of the present invention may transmit a predetermined packet to the wireless power receiver 20, The wireless power receiver 20 can notify the electronic device 30 if the connected wireless power transmitter 10 is determined to support the fast charge mode. The electronic device 30 may indicate that fast charging is possible through a predetermined display means, which may be, for example, a liquid crystal display.

In addition, the user of the electronic device 30 may select a predetermined fast charge request button displayed on the liquid crystal display means to control the wireless power transmitter 10 to operate in the fast charge mode. In this case, the electronic device 30 may transmit a predetermined fast charge request signal to the wireless power receiver 20 when the quick charge request button is selected by the user. The wireless power receiver 20 can generate a charging mode packet corresponding to the received fast charging request signal and send it to the wireless power transmitter 10 to switch the normal low power charging mode to the fast charging mode.

2 is a block diagram illustrating a wireless charging system according to another embodiment of the present invention.

For example, as shown in 200a, the wireless power receiver 20 may be configured with a plurality of wireless power receiving devices, wherein a plurality of wireless power receiving devices are connected to one wireless power transmitter 10, Charging may also be performed. In this case, the wireless power transmitter 10 may distribute power to a plurality of wireless power receiving apparatuses in a time division manner, but the present invention is not limited thereto. For example, the wireless power transmitter 10 may transmit Power can be distributed and transmitted to a plurality of wireless power receiving apparatuses using different allocated frequency bands.

At this time, the number of wireless power receiving apparatuses connectable to one wireless power transmitting apparatus 10 is set to at least one of the required power amount for each wireless power receiving apparatus, the battery charging state, the power consumption amount of the electronic apparatus, Can be determined adaptively based on

As another example, as shown in FIG. 200B, the wireless power transmitter 10 may be composed of a plurality of wireless power transmission devices. In this case, the wireless power receiver 20 may be coupled to a plurality of wireless power transmission devices at the same time, and may receive power from the connected wireless power transmission devices at the same time to perform charging. At this time, the number of wireless power transmission apparatuses connected to the wireless power receiver 20 may be adaptively calculated based on the required power amount of the wireless power receiver 20, the battery charging status, the power consumption amount of the electronic apparatus, Can be determined.

3 is a diagram for explaining a sensing signal transmission procedure in a wireless charging system according to an embodiment of the present invention.

As an example, the wireless power transmitter may be equipped with three transmit coils 111, 112, 113. Each transmit coil may overlap a portion of the transmit coil with a different transmit coil, and the wireless power transmitter may include a predetermined sense signal 117, 127 for sensing the presence of the wireless power receiver through each transmit coil - And sequentially transmits digital ping signals in a predefined order.

As shown in FIG. 3, the wireless power transmitter sequentially transmits the detection signal 117 through the primary sensing signal transmission procedure shown in reference numeral 110, and receives a signal strength indicator (Signal Strength Indicator 116 (or signal strength packet) may be received. Subsequently, the wireless power transmitter sequentially transmits the detection signal 127 through the secondary detection signal transmission procedure shown in the reference numeral 120, and the signal strength indicator 126 is transmitted to the transmission coils 111 and 112 It is possible to control the efficiency (or charging efficiency) - that is, the state of alignment between the transmitting coil and the receiving coil - to identify a good transmitting coil and to allow power to be delivered through the identified transmitting coil, .

As shown in FIG. 3, the reason why the wireless power transmitter performs the two detection signal transmission procedures is to more accurately identify to which transmission coil the reception coil of the wireless power receiver is well aligned.

If the signal strength indicators 116 and 126 are received at the first transmission coil 111 and the second transmission coil 112 as shown in the aforementioned numerals 110 and 120 of FIG. 3, Selects a transmission coil having the best alignment based on the received signal strength indicator 126 in each of the first transmission coil 111 and the second transmission coil 112 and performs wireless charging using the selected transmission coil .

4 is a state transition diagram for explaining the wireless power transmission procedure defined in the WPC standard.

Referring to FIG. 4, power transmission from a transmitter to a receiver according to the WPC standard is largely divided into a selection phase 410, a ping phase 420, an identification and configuration phase 430, And a power transfer phase (step 440).

The selection step 410 may be a phase transition when a specific error or a specific event is detected while initiating a power transmission or maintaining a power transmission. Here, the specific error and the specific event will become clear through the following description. Also, in a selection step 410, the transmitter may monitor whether an object is present on the interface surface. If the transmitter detects that an object is placed on the interface surface, it can transition to the step 420 (S401). In the selection step 410, the transmitter transmits an analog ping signal of a very short pulse and can detect whether an object exists in the active area of the interface surface based on the current change of the transmission coil.

In step 420, the transmitter activates the receiver when an object is sensed, and transmits a digital ping to identify whether the receiver is a WPC compliant receiver. If the transmitter does not receive a response signal for the digital ping (e.g., a signal strength indicator) from the receiver in step 420, then the transmitter may transition back to the selection step 410 (S402). Also, in step 420, the transmitter may transition to a selection step 410 when receiving a signal indicating completion of power transmission from the receiver, i.e., a charging completion signal (S403).

Once the ping stage 420 is complete, the transmitter may transition to an identification and configuration step 430 to collect receiver identification and receiver configuration and status information (S404).

In the identifying and configuring step 430, the sender may determine whether the packet is unexpected, whether a desired packet is received during a predefined period of time (time out), a packet transmission error (transmission error) (No power transfer contract), the process can be shifted to the selection step 410 (S405).

Once the identification and configuration for the receiver is complete, the transmitter may transition to power transfer step 440, which transmits the wireless power (S406).

In the power transfer step 440, the transmitter determines whether an unexpected packet is received, a desired packet is received for a predefined period of time (time out), a violation of a predetermined power transmission contract occurs transfer contract violation, and if the charging is completed, the selection step 410 can be performed (S407).

In addition, in the power transfer step 440, if the transmitter needs to reconfigure the power transfer contract according to changes in the transmitter state, etc., it may transition to the identification and configuration step 430 (S408).

The power transmission contract may be set based on the status and characteristic information of the transmitter and the receiver. For example, the transmitter status information may include information on the maximum amount of transmittable power, information on the maximum number of receivable receivers, and the receiver status information may include information on the requested power and the like.

5 is a state transition diagram for explaining a wireless power transmission procedure defined in the PMA standard;

Referring to FIG. 5, power transmission from a transmitter to a receiver according to the PMA standard is largely divided into a standby phase 510, a digital ping phase 520, an identification phase 530, A Power Transfer Phase 540, and an End of Charge Phase 550. FIG.

The waiting step 510 may be a step of performing a receiver identification procedure for power transmission or transitioning to a specific error or a specific event while sensing a power transmission. Here, the specific error and the specific event will become clear through the following description. Also, at a standby step 510, the transmitter may monitor whether an object is present on the Charging Surface. If the transmitter detects that an object has been placed on the charging surface, or if an RXID retry is in progress, the digital switching may proceed to step 520 (S501). Here, RXID is a unique identifier assigned to a PMA compatible receiver. At the standby step 510, the transmitter transmits an analog ping of a very short pulse and, based on the change in current of the transmitting coil, causes the object to move to the active surface of the interface surface-for example, It can be detected whether or not it exists.

The transmitter transited to the digital pinging step 520 sends a digital finger signal to identify whether the sensed object is a PMA compatible receiver. When sufficient power is supplied to the receiver by the digital ping signal transmitted by the transmitter, the receiver can modulate the received digital ping signal according to the PMA communication protocol and transmit a predetermined response signal to the transmitter. Here, the response signal may include a signal strength indicator indicating the strength of the power received at the receiver. At step 520, the receiver can transition to the identification step 530 if a valid response signal is received (S502).

If the response signal is not received or it is determined that it is not a PMA compliant receiver, i.e., it is a Foreign Object Detection (FOD), at step 520, the transmitter can transition to the wait step 510 (S503). As an example, a foreign object (FO) may be a metallic object including coins, keys, and the like.

In the identifying step 530, the transmitter may transition to the wait step 510 if the receiver identification procedure fails or the receiver identification procedure must be re-performed and the receiver identification procedure has not been completed for a predefined period of time S504).

If the transmitter succeeds in identifying the receiver, the transmitter may transition from the identifying step 530 to the power transfer step 540 and start charging (S505).

In the power transfer step 540, the transmitter determines if the desired signal is not received within a predetermined time (Time Out), an FO is detected, or if the voltage of the transmit coil exceeds a predefined reference value, (S506).

Also, in the power transmission step 540, if the temperature sensed by the temperature sensor provided inside the transmitter exceeds a predetermined reference value, the transmitter may transition to the completion of charging step 550 (S507).

In the charge completion step 550, if the transmitter is confirmed that the receiver has been removed from the charging surface, the transmitter can transition to the standby state 510 (S509).

If the measured temperature drops below the reference value in the over temperature state, the transmitter may transition from the charging completion step 550 to the digital charging step 520 in step S510.

In the digital ping phase 520 or the power transfer phase 540, the transmitter may transition to the charge completion phase 550 (S508 and S511) when an End Of Charge (EOC) request is received from the receiver.

6 is a block diagram illustrating a structure of a wireless power transmitter according to an embodiment of the present invention.

6, the wireless power transmitter 600 may include a power conversion unit 610, a power transmission unit 620, a communication unit 630, a control unit 640, and a sensing unit 650 . It should be noted that the configuration of the wireless power transmitter 600 described above is not necessarily an essential configuration, and may be configured to include more or less components.

As shown in FIG. 6, when power is supplied from the power supply unit 660, the power conversion unit 610 may convert the power to a predetermined intensity.

For this, the power conversion unit 610 may include a DC / DC conversion unit 611 and an amplifier 612.

The DC / DC converting unit 611 may convert DC power supplied from the power supply unit 650 into DC power having a specific intensity according to a control signal of the controller 640. [

At this time, the sensing unit 650 may measure the voltage / current of the DC-converted power and provide the measured voltage / current to the controller 640. In addition, the sensing unit 650 may measure the internal temperature of the wireless power transmitter 600 and may provide the measurement result to the controller 640 in order to determine whether overheating occurs. For example, the control unit 640 may adaptively cut off the power supply from the power supply unit 650 or block the supply of power to the amplifier 612 based on the voltage / current value measured by the sensing unit 650 . To this end, a power cutoff circuit may be further provided at one side of the power conversion unit 610 to cut off power supplied from the power supply unit 650 or to cut off power supplied to the amplifier 612.

The amplifier 612 can adjust the intensity of the DC / DC-converted power according to the control signal of the controller 640. For example, the control unit 640 may receive the power reception status information and / or the power control signal of the wireless power receiver through the communication unit 630 and may receive the power control information based on the received power reception status information and / So that the amplification factor of the amplifier 612 can be dynamically adjusted. For example, the power reception status information may include, but is not limited to, the intensity information of the rectifier output voltage, the intensity information of the current applied to the reception coil, and the like. The power control signal may include a signal for requesting power increase, a signal for requesting power reduction, and the like.

The power transmitting unit 620 may be configured to include a multiplexer 621 (or a multiplexer), a transmitting coil 622, and the like. In addition, the power transmitting unit 620 may further include a carrier generator (not shown) for generating a specific operating frequency for power transmission.

The carrier generator may generate a specific frequency for converting the output DC power of the amplifier 612 delivered via the multiplexer 621 to AC power having a specific frequency. In the above description, the AC signal generated by the carrier generator is mixed with the output of the multiplexer 621 to generate AC power. However, this is only an example, It should be noted that they may be mixed only or later.

The frequency of the AC power transmitted to each of the transmission coils according to the embodiment of the present invention may be different from each other. In another embodiment of the present invention, the transmission coil may have a function of adjusting LC resonance characteristics for different transmission coils The resonance frequencies of the respective transmission coils may be set differently using the frequency controller.

However, when the resonance frequencies generated in each of the plurality of transmission coils are different, a separate frequency controller for controlling the frequency coils may be required to increase the size of the wireless power transmitter. Accordingly, in an embodiment of the present invention, A case where power is transmitted using the same resonance frequency even though it includes the transmission coil of Fig.

6, the power transmission unit 620 includes a multiplexer 621 and a plurality of transmission coils 622 for controlling the output power of the amplifier 612 to be transmitted to the transmission coil, that is, Th to n < th > transmit coils.

The controller 640 according to an exemplary embodiment of the present invention may transmit power through time division multiplexing for each transmission coil when a plurality of wireless power receivers are connected. For example, if the wireless power transmitter 600 has three wireless power receivers-i. E., The first through third wireless power receivers, respectively, identified through three different transmit coils, i. E., First through third transmit coils , The control unit 640 controls the multiplexer 621 so that power can be transmitted through a specific transmission coil in a specific time slot. At this time, the amount of power transmitted to the corresponding wireless power receiver may be controlled according to the length of the time slot allocated for each transmission coil, but this is only one embodiment. The power of the amplifier 612 may be controlled to control the transmission power of each wireless power receiver.

The control unit 640 may control the multiplexer 621 so that the detection signals may be sequentially transmitted through the first through n'th transmission coils 622 during the first detection signal transmission procedure. At this time, the control unit 640 can identify the time at which the sensing signal is transmitted using the timer 655. When the sensing signal transmission time arrives, the control unit 640 controls the multiplexer 621 to output a sensing signal It can be controlled to be transmitted. For example, the timer 650 can send a specific event signal to the control unit 640 at predetermined intervals during the ping transmission step. When the event signal is detected, the control unit 640 controls the multiplexer 621 to transmit the corresponding event signal It is possible to control the digital ping to be transmitted through the coil.

In addition, the control unit 640 may transmit a predetermined transmission coil identifier for identifying a signal strength indicator (Signal Strength Indicator) through a transmission coil from the demodulation unit 632 during the first detection signal transmission procedure, Lt; / RTI > received signal strength indicator. In the second sensing signal sending process, the controller 640 controls the multiplexer 621 so that the sensing signal can be transmitted only through the transmitting coil (s) on which the signal strength indicator is received during the first sensing signal sending procedure You may. In another example, when there are a plurality of transmit coils in which the signal strength indicator is received during the first differential sense signal transmission procedure, the control unit 640 transmits the received transmit coil with the signal strength indicator having the largest value as the second differential sense signal In the procedure, the detection signal may be determined as a transmission coil to be transmitted first, and the multiplexer 621 may be controlled according to the determination result.

The modulator 631 may modulate the control signal generated by the controller 640 and transmit the modulated control signal to the multiplexer 621. Here, the modulation scheme for modulating the control signal includes a frequency shift keying (FSK) modulation scheme, a Manchester coding modulation scheme, a phase shift keying (PSK) modulation scheme, a pulse width modulation scheme, A differential bi-phase modulation method, and the like.

The demodulator 632 can demodulate the detected signal and transmit the demodulated signal to the controller 640 when a signal received through the transmission coil is detected. Here, the demodulated signal may include a signal strength indicator, an error correction (EC) indicator for power control during wireless power transmission, an end of charge indicator (EOC), an overvoltage / overcurrent / overheat indicator, But is not limited to, various status information for identifying the status of the wireless power receiver.

Also, the demodulator 632 can identify which of the transmit coils the demodulated signal is received, and provide the control unit 640 with a predetermined transmit coil identifier corresponding to the identified transmit coil.

 The demodulation unit 632 can demodulate the signal received through the transmission coil 623 and transmit the demodulated signal to the control unit 640. In one example, the demodulated signal may include, but is not limited to, a signal strength indicator, and the demodulated signal may include various status information of the wireless power receiver.

In one example, the wireless power transmitter 600 may obtain the signal strength indicator through in-band communication that uses the same frequency used for wireless power transmission to communicate with the wireless power receiver.

In addition, the wireless power transmitter 600 can transmit wireless power using the transmit coil 622, as well as exchange various information with the wireless power receiver via the transmit coil 622. As another example, the wireless power transmitter 600 may further include a separate coil corresponding to each of the transmission coils 622 (i.e., the first to n < th > transmission coils) It should be noted that it may also perform in-band communication with the receiver.

Although the wireless power transmitter 600 and the wireless power receiver perform in-band communication in the description of FIG. 6, this is merely an example, and the frequency band used for the wireless power signal transmission Directional communication through different frequency bands. For example, the near-end bi-directional communication may be any one of low-power Bluetooth communication, RFID communication, UWB communication, and Zigbee communication.

In particular, the wireless power transmitter 600 according to an embodiment of the present invention may adaptively provide a fast charge mode and a general low power charge mode at the request of the wireless power receiver.

The wireless power transmitter 600 can transmit a signal of a predetermined pattern, which is called a first packet for convenience of explanation, when the fast charge mode is supported. The wireless power receiver 600 may identify that the wireless power transmitter 600 being connected is capable of fast charge when the first packet is received.

In particular, the wireless power receiver may send a first response packet to the wireless power transmitter 600 requesting fast charging if fast charging is required.

In particular, the wireless power transmitter 600 may automatically switch to the fast charge mode and initiate fast charge when a predetermined time has elapsed after the first response packet is received.

For example, when the control unit 640 of the wireless power transmitter 600 transits to the power transmission step 440 or 540 of FIGS. 4 through 5, the control unit 640 controls the first packet to be transmitted through the transmission coil 622 However, this is only one example, and another example of the present invention may be the first packet sent out in the identification and configuration step 430 of FIG. 4 or the identifying step 530 of FIG.

It should be noted that another embodiment of the present invention may transmit encoded information that can identify whether or not fast charge support is possible to the digital ring signal transmitted by the wireless power transmitter 600. [

The wireless power receiver may send a predetermined charge mode packet to the wireless power transmitter 600 where the charge mode is set to fast charge if a fast charge is needed at any point in the power transfer phase. Here, the details of the configuration of the charge mode packet will be clarified through the description of FIGS. 7 to 11 to be described later. Of course, the wireless power transmitter 600 and the wireless power receiver can control the internal operation so that power corresponding to the fast charge mode can be sent and received when the charge mode is changed to the fast charge mode. For example, when the charging mode is changed from the normal low-power charging mode to the fast-charging mode, the overvoltage determination criterion, the over temperature criterion, the low-voltage / high- Level (Optimum Voltage Level), power control offset, and the like can be changed and set.

For example, when the charging mode is changed from the normal low-power charging mode to the fast-charging mode, the threshold voltage for determining the overvoltage may be set to be high enough to enable fast charging. As another example, the critical temperature for determining whether overheating occurs may be set high considering the temperature rise due to fast charging. As another example, the power control offset value, which means the minimum level at which the power at the transmitter is controlled, may be set to a larger value than the general low-power charging mode so that it can converge quickly to the desired target power level in the fast-charge mode.

7 is a diagram for explaining a packet format according to an electromagnetic induction wireless power transmission procedure according to an embodiment of the present invention.

Referring to FIG. 7, a packet format 700 used for information exchange between a wireless power transmitter and a wireless power receiver includes a preamble (preamble) 710 for acquiring synchronization for demodulating the packet and identifying an accurate start bit of the packet, A header field 720 for identifying a type of a message included in the packet, a message 730 field for transmitting the contents of the packet (or payload) And a checksum (740) field for identifying whether or not an error has occurred.

As shown in FIG. 7, the packet receiver may identify the size of the message 730 included in the packet based on the header 720 value.

In addition, the header 720 may be defined for each step of the wireless power transmission procedure, and some values of the header 720 may be defined at different steps. For example, referring to FIG. 7, it should be noted that the header value corresponding to the end power transfer in the ping phase and the power transfer termination in the power transfer phase may be equal to 0x02.

The message 730 includes data to be transmitted at the transmitter of the packet. For example, the data contained in the message 730 field may be, but is not limited to, a report, a request, or a response to the other party.

The packet 700 according to another embodiment of the present invention may further include at least one of transmitter identification information for identifying a transmitter that transmitted the packet and receiver identification information for identifying a receiver to receive the packet. Here, the transmitter identification information and the receiver identification information may include IP address information, MAC address information, product identification information, and the like. However, the present invention is not limited thereto, and information that can distinguish the receiver and the transmitter on the wireless charging system is sufficient.

The packet 700 according to another embodiment of the present invention may further include predetermined group identification information for identifying the receiving group when the corresponding packet is to be received by a plurality of apparatuses.

FIG. 8 is a diagram for explaining the types of packets that a wireless power receiving apparatus according to an electromagnetic induction type wireless power transmission procedure according to an embodiment of the present invention can transmit in a ping stage.

8, the wireless power receiving apparatus can transmit a signal strength packet or a power transmission stop packet in the short-ranging step.

Referring to reference numeral 801 in FIG. 8, a message format of a signal strength packet according to an exemplary embodiment may include a signal strength value having a size of 1 byte. The signal strength value may indicate the degree of coupling between the transmitting coil and the receiving coil and may be calculated based on the rectifier output voltage in the digital ping section, the open circuit voltage measured in the output blocking switch, Lt; / RTI > The signal strength value may range from a minimum of 0 to a maximum of 255 and may have a value of 255 if the actual measured value for a particular variable is equal to the maximum value of that variable (Umax).

For example, the signal strength value may be calculated as U / Umax * 256.

Referring to FIG. 8, the message format of the power transmission stop packet according to an exemplary embodiment may include an end power transfer code having a size of 1 byte.

The reasons why the wireless power receiving apparatus requests the wireless power transmitter to stop the power transmission include charging completion, internal fault, overtemperature, overvoltage, overcurrent, battery But is not limited to, Battery Failure, Reconfigure, and No Response. It should be noted that the power transmission interruption code may be further defined in response to each new power transmission interruption reason.

Charging complete can be used to indicate that the charging of the receiver battery is complete. Internal errors can be used when a software or logical error in the internal operation of the receiver is detected.

Overheating / overvoltage / overcurrent can be used when the measured temperature / voltage / current value at the receiver exceeds the defined threshold for each.

Battery damage can be used if it is determined that there is a problem with the receiver battery.

Reconfiguration can be used when renegotiation is required for power transmission conditions. No response can be used if the transmitter's response to the control error packet - meaning increasing or decreasing the strength of the power - is judged to be unhealthy.

9 is a diagram for explaining a message format of an identification packet according to an electromagnetic induction wireless power transmission procedure according to an embodiment of the present invention.

9, the message format of the identification packet includes a Version Information field, a Manufacturer Information field, an Extension Indicator field, and a Basic Device Identification Information field Lt; / RTI >

In the version information field, revision version information of a standard applied to the wireless power receiving apparatus can be recorded.

In the manufacturer information field, a predetermined identification code for identifying the manufacturer of the wireless power receiving apparatus may be recorded.

The extension indicator field may be an indicator for identifying whether an extended identification packet including the extended device identification information exists. For example, if the value of the extension indicator is 0, it means that there is no extension identification packet, and if the extension indicator value is 1, it means that the extension identification packet exists after the identification packet.

Referring to reference numerals 901 to 902, if the extension indicator value is 0, the device identifier for the corresponding wireless power receiver may be a combination of manufacturer information and basic device identification information. On the other hand, if the extension indicator value is 1, the device identifier for the wireless power receiver may be a combination of manufacturer information, basic device identification information, and extended device identification information.

10 is a diagram for explaining a message format of a configuration packet and a power control hold packet according to an electromagnetic induction wireless power transmission procedure according to an embodiment of the present invention.

10, the message format of the configuration packet may have a length of 5 bytes, and may include a power class field, a maximum power field, a power control field, A count field, a window size field, a window offset field, and the like.

The power rating field may record the power rating assigned to the wireless power receiver.

The maximum power field may record the intensity value of the maximum power that can be provided at the rectifier output of the wireless power receiver.

For example, in the case where the power level is a and the maximum power is b, the maximum power amount Pmax desired to be provided at the rectifier output of the wireless power receiving apparatus can be calculated as (b / 2) * 10 ^a .

The power control field can be used to indicate which algorithm should be used to control the power in the wireless power transmitter. For example, if the power control field value is 0, it implies applying the power control algorithm defined in the standard, and if the power control field value is 1, it means that the power control is performed according to the algorithm defined by the manufacturer.

The count field may be used to record the number of option configuration packets that the wireless power receiving device will send in the identification and configuration phase.

The window size field may be used to record the window size for calculating the average received power. As an example, the window size may be a positive integer value that is greater than zero and has a unit of 4 ms.

In the window offset field, information for identifying the time from the end of the average reception power calculation window to the transmission start point of the next received power packet may be recorded. In one example, the window offset may be a positive integer value greater than zero and in units of 4 ms.

Referring to reference numeral 1002, the message format of the power control hold packet may be configured to include a power control hold time (T_delay). A plurality of power control hold packets may be transmitted during the identification and configuration phase. For example, up to seven power control pending packets may be transmitted. The power control hold time (T_delay) may have a value between a predefined power control hold minimum time (T_min: 5 ms) and a power control hold maximum time (T_max: 205 ms). The wireless power transmission apparatus can perform power control using the power control retention time of the power control retention packet last received in the identification and configuration step. Also, the wireless power transmission apparatus can use the T_min value as the T_delay value when the power control hold packet is not received in the identification and configuration step.

The power control retention time may refer to the time that the wireless power transmission apparatus should wait without performing the power control before performing the actual power control after receiving the latest control error packet.

11 is a diagram for explaining a type of a packet that can be transmitted in a power transmission step and a message format thereof by a wireless power receiving apparatus according to an electromagnetic induction wireless power transmission procedure according to an embodiment of the present invention.

Referring to FIG. 11, in the power transmission step, a packet that can be transmitted by the wireless power receiving apparatus includes a control error packet, an end power transfer packet, a received power packet, A packet (Charge Status Packet), a packet defined by a manufacturer, and the like.

Reference numeral 1101 denotes a message format of a control error packet composed of a 1-byte control error value. Here, the control error value may be an integer value ranging from -128 to +127. If the control error value is negative, the transmission power of the radio power transmission apparatus decreases, and if it is positive, the transmission power of the radio power transmission apparatus can be increased.

Reference numeral 1102 denotes a message format of a control error packet composed of a 1-byte end power transfer code.

Reference numeral 1103 denotes a message format of a received power packet including a 1-byte received power value. Here, the received power value may correspond to the average rectifier received power value calculated during a predetermined period. The actual received power amount (P _received ) can be calculated based on the maximum power and the power class included in the configuration packet 1001. As an example, the actual amount of power received can be calculated by (received power value / 128) * (maximum power / 2) * (10 ^{power rating} ).

Reference numeral 1104 denotes a message format of a Charge Status Packet consisting of a 1-byte Charge Status Value. The charge state value may indicate the battery charge amount of the wireless power receiving device. For example, the charge state value 0 means a completely discharged state, the charge state value 50 may mean a 50% charge state, and the charge state value 100 may mean a full charge state. If the wireless power receiving device does not include a rechargeable battery or can not provide charge state information, the charge state value may be set to OxFF.

12 is a view for explaining the arrangement of a plurality of transmission coils and the distance from the shielding member according to an embodiment of the present invention.

Referring to FIG. 12, three transmission coils can be arranged. At least one of the plurality of transmission coils may be disposed in an overlapped manner in order to perform a uniform power transmission within a constant sized charging area. 12, the first coil 1210 and the second coil 1220 are disposed on the first layer side by side at a predetermined interval on the shielding member 1240, and the third coil 1230 is disposed on the first coil and the second coil And can be superimposed on the second layer.

The first coil 1210, the second coil 1220 and the third coil 1230 may be manufactured according to the specifications of the coils defined in WPC or PMA and may be manufactured to the same extent can do.

For example, the transmit coil may have the specifications shown in Table 1 below.

Table 1 is a specification for the A13 type transmission coil defined in the WPC. In one embodiment, the first coil 1210, the second coil 1220, and the third coil 1230 have outer lengths defined in Table 1, Inner length, outer width, inner width, thickness, and winding. Of course, the first coil 1210, the second coil 1220, and the third coil 1230 may have the same physical characteristics within an error range by the same manufacturing process.

12, each of the first coil 1210, the second coil 1220, and the third coil 1230 may have different values of inductance measured depending on positions where the first coil 1210, the second coil 1220, and the third coil 1230 are disposed in relation to the shielding material.

For example, the first coil 1210 and the second coil 1220 satisfy the specifications of Table 1 and have an inductance of 12.5 uH. The third coil 1230 is spaced apart from the shielding member by a distance May have an inductance that is less than 12.5 uH different from the first coil 1210 and the second coil 1220.

For example, the first coil 1210 and the second coil 1220 are disposed in contact with the shielding material, while the third coil 1230 may be disposed apart from the shielding material by a predetermined height.

In one embodiment, an adhesive may be disposed between the first coil 1210, the second coil 1220, or the third coil 1230 and the shielding material.

Therefore, in an embodiment of the present invention, the third coil 1230 is wound around the first coil 1210 and the second coil 1220 in order to have the same inductance as the first coil 1210 and the second coil 1220. [ You may have more players than a player (for example, 0.5 times or 1 time or 2 times).

In one embodiment, the third coil 1230 may have 12.5 times or 13 times or 14 times of turns.

In another embodiment, the turns of the first coil 1210 and the second coil 1220 may be made smaller than the third coil 1230 to have the same inductance as the third coil 1230.

In one embodiment, when the third coil 1230 has several more turns than the first coil 1230 and the second coil 1220, the outer length, outer width, and thickness are the same, The width can be different.

In one embodiment, when the third coil 1230 has several more turns than the first coil 1230 and the second coil 1220, the inner length, inner width, and thickness are the same, The width can be different.

In one embodiment, when the third coil 1230 has several more turns than the first coil 1230 and the second coil 1220, the outer length, outer width, inner width, The length can be different.

In one embodiment, when the third coil 1230 has several more turns than the first coil 1230 and the second coil 1220, the outer length, outer width, inner length, The width can be different.

In one embodiment, when the third coil 1230 has several more turns than the first coil 1230 and the second coil 1220, the outer width, inner length, inner width, The length can be different.

In one embodiment, in the case where the third coil 1230 has several more turns than the first coil 1230 and the second coil 1220, the outer length, the inner length, the inner width, The width can be different.

In other words, the centrally located third coil 1230 is located farther from the shield than the first coil 1210 and the second coil 1220, and the measured inductance is greater than the inductance of the first coil 1210 and the second coil 1220 And the length of the conductor constituting the third coil 1230 may be made longer than that of the first coil 1210 and the second coil 1220 to adjust the inductance to be the same.

The length of the wire constituting the third coil 1230 is made slightly longer than that of the first coil 1210 and the second coil 1220 so that the third coil 1230 is connected to the first coil 1230, The inductance of the three coils may be equal to 12.5uH, although they are located farther from the shield than the second coil 1220. In one embodiment, the coils' inductance is equal to an error within +/- 0.5uH Range. ≪ / RTI >

As the distance from the shielding material to the shielding coils increases, the measured inductance of the transmission coil overlaps with the shielding material. The longer the distance to the shielding material, the longer the length of the transmission coil to increase the inductance.

When the inductances of the first coil 1210, the second coil 1220 and the third coil 1230 are different from each other, a resonance circuit including capacitors different from each other depending on inductances and a resonance circuit May be required for each drive circuit.

13 is a view for explaining three drive circuits including a full-bridge inverter in a wireless power transmitter including a plurality of coils according to an embodiment of the present invention.

13, when three transmission coils included in a wireless power transmitter have different inductances, three driving circuits 1310 connected to respective transmission coils and capacitors for generating the same resonance frequency Three LC resonant circuits 1320 are required.

Although the wireless power transmitter includes a plurality of transmit coils, the resonant frequency that the wireless power transmitter generates to carry out the power transmission should not depend on each of the transmit coils and must conform to the standard resonant frequency supported by the wireless power transmitter.

The resonance frequency generated in the LC resonance circuit 1320 may vary depending on the inductance of the coil and the capacitance of the capacitor.

For example, the resonant frequency (fr) may be 100 KHz, and when the capacitance of the capacitor connected to the transmission coil to generate the resonance frequency is 200 nF, if only one capacitor is used, All should meet 12.5uH. When the inductances of the three transmission coils are different from each other, three capacitors having different capacitances corresponding to each other are required in order to generate a resonance frequency of 100 kHz. In addition, three drive circuits 1310 including an inverter for applying an AC voltage in each of the LC resonance circuits 1320 are also required.

FIG. 14 is a diagram illustrating a wireless power transmitter including a plurality of coils and including one drive circuit according to an embodiment of the present invention. Referring to FIG.

14, if the inductances of the three transmission coils are the same, the wireless power transmitter may include only one drive circuit 1410, and one drive circuit 1410 and three transmit coils, It is possible to control the switch 1430 to connect the transmission coil having the highest efficiency.

Compared with FIG. 13, the wireless power transmitter can reduce the area occupied by the components by using only one drive circuit 1410, thereby making it possible to miniaturize the wireless power transmitter itself and reduce the cost of raw materials required for manufacturing .

In one embodiment, the wireless power transmitter may use a signal strength indicator in the ping stage to calculate the power transfer efficiency between the three transmit coils and the receive coils.

Alternatively, in another embodiment, the wireless power transmitter may calculate a coupling coefficient between the transmitting and receiving coils to select a transmitting coil with a high coupling coefficient.

Alternatively, the wireless power transmitter may calculate a Q factor to control the switch 1430 to identify the high transmit coil of the queue factor and connect it to the drive circuit 1410.

15 is a view for explaining a drive circuit including a full-bridge inverter according to an embodiment of the present invention.

Referring to FIG. 15, a power transmitter included in a wireless power transmitter can generate a specific operating frequency for power transmission. The power transfer section may include an inverter 1510, an input power supply 1520 and an LC resonant circuit 1530.

The inverter 1510 can convert the voltage signal from the input power supply and transmit it to the LC resonance circuit 1530. [ In one embodiment, the inverter 1510 may be a full-bridge inverter or a half-bridge inverter.

The power transfer section can use a full bridge inverter for higher output than the output by the half bridge inverter. The full bridge inverter can be applied to the LC resonance circuit 1530 by outputting a voltage two times higher than that of the half bridge inverter by using four switches in the form of adding two switches to the half bridge inverter.

16 is a diagram for explaining a plurality of switches for connecting any one of a plurality of transmission coils to a drive circuit according to an embodiment of the present invention.

16, the power transmission unit includes a drive circuit 1610 for converting an input voltage, a switch 1620 for connecting a drive circuit 1610 and an LC resonance circuit, a plurality of transmission coils 1630, One capacitor 1640 connected in series and a control unit 1650 for controlling the opening and closing of the switch 1620.

The control unit 1650 can perform control to identify the transmission coil among the plurality of transmission coils 1630 and the transmission coil having the highest power transmission efficiency and to close the switch to connect the identified transmission coil to the drive circuit 1610 .

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.

Claims (21)

When an object is sensed in the charging area, selecting a transmission coil having the highest power transmission efficiency among N transmission coils arranged so that at least one transmission coil is superposed on each other; And
Controlling a switch among the N switches connecting the selected transmission coil and a drive circuit;
/ RTI >
Wherein the wires constituting each of the N transmission coils are adjusted in length corresponding to respective positions with respect to the shielding material and have the same inductance,
A method of controlling a wireless power transmitter. The method according to claim 1,
Each of the N transmit coils connected in parallel with each of the N switches is individually connected in series with each of the N switches,
A method of controlling a wireless power transmitter. The method according to claim 1,
Wherein the N transmit coils are connected in series with one capacitor,
A method of controlling a wireless power transmitter. The method according to claim 1,
Each of the N transmit coils having a different inductance corresponding to a different position with respect to the shielding material,
A method of controlling a wireless power transmitter. 5. The method of claim 4,
Wherein the number of turns of each of the N transmitting coils varies depending on a distance from the shielding member,
A method of controlling a wireless power transmitter. 5. The method of claim 4,
Wherein a distance between each of the N transmitting coils is larger than a distance from the shielding member,
A method of controlling a wireless power transmitter. 5. The method of claim 4,
Wherein the number of turns of each of the N transmit coils is 0.5 to 2 times,
A method of controlling a wireless power transmitter. The method according to claim 1,
Wherein the transmitting coil transmits power to the receiving coil using a specific resonant frequency,
A method of controlling a wireless power transmitter. The method according to claim 1,
Wherein the drive circuit includes an inverter that converts a DC voltage from a power source to an AC voltage.
A method of controlling a wireless power transmitter. The method according to claim 1,
The selected transmission coil includes:
Wherein one of said N switches is closed and connected in series between one said drive circuit and said capacitor,
A method of controlling a wireless power transmitter. A computer-readable recording medium storing a program for executing the method according to any one of claims 1 to 10. N transmitting coils in which at least one of them is arranged to overlap with each other;
N switches connecting the N transmit coils and the drive circuit; And
A controller for selecting a transmission coil having the highest power transmission efficiency among the N transmission coils when an object is detected in the charging area and controlling the corresponding switch among N switches connecting the selected transmission coil and the drive circuit;
/ RTI >
Wherein the wires constituting each of the N transmission coils are adjusted in length corresponding to respective positions with respect to the shielding material and have the same inductance,
Wireless power transmitter. 13. The method of claim 12,
Each of the N transmit coils connected in parallel with each of the N switches is individually connected in series with each of the N switches,
Wireless power transmitter. 13. The method of claim 12,
Wherein the N transmit coils are connected in series with one capacitor,
Wireless power transmitter. 13. The method of claim 12,
Each of the N transmit coils having a different inductance corresponding to a different position with respect to the shielding material,
Wireless power transmitter. 16. The method of claim 15,
Wherein the number of turns of each of the N transmitting coils varies depending on a distance from the shielding member,
Wireless power transmitter. 16. The method of claim 15,
Wherein a distance between each of the N transmitting coils is larger than a distance from the shielding member,
Wireless power transmitter. 16. The method of claim 15,
Wherein each of the N transmit coils has a difference of 0.5 or 1 time,
Wireless power transmitter. 13. The method of claim 12,
Wherein the transmitting coil transmits power to the receiving coil using a specific resonant frequency,
Wireless power transmitter. 13. The method of claim 12,
Wherein the drive circuit includes an inverter that converts a DC voltage from a power source to an AC voltage.
Wireless power transmitter. 13. The method of claim 12,
The selected transmission coil includes:
Wherein one of said N switches is closed and connected in series between one said drive circuit and said capacitor,
Wireless power transmitter.

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