KR20170107155A - Wireless Charging Method and Apparatus and System therefor - Google Patents

Abstract

The present invention relates to a wireless charging method and apparatus and system therefor. A wireless power transmitter for wirelessly transmitting power to a wireless power receiver according to an embodiment of the present invention includes a communication part which receives information on the reception sensitivity of a terminal having the wireless power receiver, and a determination part which compares the reception sensitivity with a predetermined reference value to determine whether the reception sensitivity of the terminal is normal, and determining whether to change a pulse width modulation frequency according to the determination result; a change part which changes the pulse width modulation frequency when the change of the pulse width modulation frequency is determined, and a power transmission part for generating and transmitting power corresponding to the pulse width modulation signal generated at the changed frequency. Accordingly, it is possible to minimize the deterioration of the wireless communication reception sensitivity of a terminal due to wireless charging.

Description

Technical Field [0001] The present invention relates to a wireless charging method, and a wireless charging method and apparatus and system therefor.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless power transmission technique, and more particularly, to a wireless charging method for adaptively changing a pulse width modulation signal frequency according to receiving sensitivity of a terminal equipped with a wireless power receiver, and an apparatus and system therefor.

Recently, as the information and communication technology rapidly develops, a ubiquitous society based on information and communication technology is being made.

In order for information communication devices to be connected anytime and anywhere, sensors equipped with a computer chip having a communication function must be installed in all facilities of the society. Therefore, power supply problems of these devices and sensors are becoming a new challenge. In addition, mobile devices such as Bluetooth handsets and iPods, as well as mobile phones, have been rapidly increasing in number, and charging the battery has required users time and effort. As a way to solve this problem, wireless power transmission technology has recently attracted attention.

The wireless power transmission technology (wireless power transmission or wireless energy transfer) is a technology to transmit electric energy from the transmitter to the receiver wirelessly using the induction principle of the magnetic field. In the 1800s, electric motor or transformer And thereafter, a method of transmitting electrical energy by radiating electromagnetic waves such as high frequency, microwave, and laser has also been attempted. Our electric toothbrushes and some wireless shavers are actually charged with electromagnetic induction.

Up to the present, energy transmission using radio may be roughly classified into a magnetic induction method, an electromagnetic resonance method, and an RF transmission method using a short wavelength radio frequency.

In the magnetic induction method, when two coils are adjacent to each other and a current is supplied to one coil, a magnetic flux generated at this time causes an electromotive force to the other coils. As a technology, . The magnetic induction method has the disadvantage that it can transmit power of up to several hundred kilowatts (kW) and the efficiency is high, but the maximum transmission distance is 1 centimeter (cm) or less, so it is usually adjacent to the charger or the floor.

The self-resonance method is characterized by using an electric field or a magnetic field instead of using electromagnetic waves or currents. The self-resonance method is advantageous in that it is safe to other electronic devices or human body since it is hardly influenced by the electromagnetic wave problem. On the other hand, it can be used only at a limited distance and space, and has a disadvantage that energy transfer efficiency is somewhat low.

Short wavelength wireless power transmission - simply, RF transmission - takes advantage of the fact that energy can be transmitted and received directly in radio wave form. This technology is a RF power transmission system using a rectenna. Rectena is a combination of an antenna and a rectifier, which means a device that converts RF power directly into direct current power. That is, the RF method is a technique of converting an AC radio wave into DC and using it. Recently, as the efficiency has improved, commercialization has been actively researched.

Wireless power transmission technology can be applied not only to mobile, but also to various industries such as IT, railroad, and household appliance industry.

The wireless power transmission apparatus uses a power converter called a buck converter to control the intensity of the output power.

The output voltage of the buck converter is determined according to the duty ratio of the pulse width modulated signal, and the pulse width modulated signal can be generated at a predetermined frequency.

However, in the related art, a harmonic component is generated due to a frequency used for generating a pulse width modulation signal, and some harmonic components have a problem that the reception sensitivity of a terminal equipped with a wireless power receiver is lowered, .

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems of the prior art, and it is an object of the present invention to provide a wireless charging method and apparatus and system therefor.

It is another object of the present invention to provide a wireless charging method for adaptively changing the pulse width modulation signal frequency according to reception sensitivity of a terminal equipped with a wireless power receiver, and an apparatus and system therefor.

It is still another object of the present invention to normalize reception sensitivity by identifying whether a decrease in reception sensitivity of a terminal equipped with a wireless power receiver is due to wireless charging and changing the pulse width modulation signal frequency according to the result of identification A possible wireless charging method and apparatus and system therefor are provided.

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.

The present invention can provide a wireless charging method and apparatus and system therefor.

A wireless power transmitter for wirelessly transmitting power to a wireless power receiver according to an exemplary embodiment of the present invention includes a communication unit for receiving information on a reception sensitivity of a terminal equipped with the wireless power receiver and a communication unit for comparing the reception sensitivity with a predetermined reference value A determination unit for determining whether the reception sensitivity of the terminal is normal and determining whether to change the pulse width modulation frequency according to the determination result; and a determination unit for determining whether the pulse width modulation frequency is changed, And a power transmitter for generating and transmitting power corresponding to the pulse width modulation signal generated by the changed frequency.

The wireless power transmitter may further include a controller for determining whether the reception sensitivity is deteriorated by a harmonic component generated by the pulse width modulation frequency.

If the reception sensitivity is not normal, the control unit adjusts the transmission power to a predetermined minimum power level. Then, when the reception sensitivity becomes normal, it is determined that the reception sensitivity is deteriorated by the harmonic component, To be changed.

Also, the controller may control the intensity of the transmission power by adjusting a duty rate of the pulse width modulation signal.

Also, the pulse width modulation frequency may be controlled to be changed in units of preset frequency offset until the reception sensitivity becomes normal.

The information on the reception sensitivity may include a received signal strength indicator (RSSI), a reference signal received power (RSRP), a reference signal reception quality (RSRQ) And a signal to interference plus noise ratio (SINR).

In addition, the information on the reception sensitivity can be received through the in-band communication.

In addition, the information about the reception sensitivity may be received through the established out-of-band communication channel with the wireless power receiver.

In addition, the communication unit may further receive information on a wireless communication frequency band allocated to the terminal, and a pulse width modulation frequency to be changed for each wireless communication frequency band may be preset and maintained.

A wireless power receiver for wirelessly receiving power from a wireless power transmitter according to another embodiment of the present invention includes a controller for acquiring reception sensitivity information of a terminal equipped with the wireless power receiver, Wherein the AC signal generated by a pulse width modulation frequency dynamically determined in accordance with the reception sensitivity information is received from the wireless power transmitter, .

The wireless charging method in a wireless power transmitter for wirelessly transmitting power to a wireless power receiver according to another embodiment of the present invention includes receiving information about reception sensitivity of a terminal equipped with the wireless power receiver, Determining whether the reception sensitivity is normal or not; determining whether the reception sensitivity is normal or not if the reception sensitivity is not normal; and determining whether the pulse width modulation frequency is changed, Changing the pulse width modulation frequency, and transmitting the generated power using the changed pulse width frequency.

The wireless charging method may further include determining whether the reception sensitivity is deteriorated by a harmonic component generated by the pulse width modulation frequency.

The step of determining whether the reception sensitivity is deteriorated by the harmonic component may include adjusting the transmission power to a predetermined minimum power level if the reception sensitivity is not normal, And confirming that the reception sensitivity due to the harmonic component has decreased when the reception sensitivity becomes normal. When the decrease in reception sensitivity due to the harmonic component is confirmed, the pulse width modulation frequency can be changed.

Also, the intensity of the transmission power can be controlled by adjusting a duty rate of the pulse width modulation signal.

The step of changing the pulse width modulation frequency may include changing the pulse width modulation frequency in units of a preset frequency offset until the reception sensitivity becomes normal.

The information on the reception sensitivity may include a received signal strength indicator (RSSI), a reference signal received power (RSRP), a reference signal reception quality (RSRQ) And a signal to interference plus noise ratio (SINR).

In addition, the information on the reception sensitivity can be received through the in-band communication.

In addition, the information about the reception sensitivity may be received through the established out-of-band communication channel with the wireless power receiver.

Further, it is possible to further receive information on the wireless communication frequency band allocated to the terminal, and the pulse width modulation frequency to be changed for each wireless communication frequency band can be preset and maintained.

A method for wireless charging in a wireless power receiver that receives power wirelessly from a wireless power transmitter in accordance with another embodiment of the present invention includes the steps of obtaining reception sensitivity information of a terminal equipped with the wireless power receiver, Transmitting the sensitivity information to the wireless power transmitter, and rectifying the AC signal received through the receiving coil and transmitting the AC signal to the load, wherein the step of generating the pulse signal includes generating the pulse width modulation frequency dynamically determined according to the reception sensitivity information The AC signal can be received from the wireless power transmitter.

The wireless charging method may further include determining whether the wireless communication reception sensitivity of the terminal is normal.

As a result of the determination, the acquired reception sensitivity information may be transmitted to the wireless power transmitter only when the wireless communication reception sensitivity is not normal.

The wireless charging method may further include acquiring wireless communication frequency band information allocated to the terminal and transmitting the acquired wireless communication frequency band information to the wireless power transmitter, The pulse width modulation frequency can be determined at a predetermined frequency set in advance.

According to another embodiment of the present invention, there is provided a computer-readable recording medium having recorded thereon a program for executing any one of the wireless charging methods.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, And can be understood and understood.

Effects of the method, apparatus and system according to the present invention will be described as follows.

An advantage of the present invention is to provide a wireless charging method and an apparatus and a system therefor that can prevent deterioration of reception sensitivity of a terminal due to wireless charging.

The present invention also provides a wireless charging method capable of removing a terminal interference signal by adaptively changing a pulse width modulation signal frequency according to reception sensitivity of a terminal equipped with a wireless power receiver, and an apparatus and a system therefor .

Further, the present invention can quickly determine whether the reception sensitivity of a terminal equipped with a wireless power receiver is due to wireless charging and change the frequency of the pulse width modulation signal according to the result of identification, thereby quickly normalizing the reception sensitivity of the terminal There is an advantage of providing a wireless charging method and apparatus and system therefor.

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 state transition diagram of a wireless power receiver supporting an electromagnetic resonance method according to an embodiment of the present invention.
FIG. 7 is a state transition diagram for explaining a state transition procedure in a wireless power transmitter supporting an electric resonance system according to an embodiment of the present invention. Referring to FIG.
8 is a flowchart illustrating a method of transmitting a wireless power in a wireless power transmitter according to an embodiment of the present invention.
9 is a flowchart illustrating a method of transmitting a wireless power in a wireless power transmitter according to another embodiment of the present invention.
10 is a flowchart illustrating a method of transmitting a wireless power in a wireless power transmitter according to another embodiment of the present invention.
11 is a block diagram of a wireless power transmitter in accordance with an embodiment of the present invention.
12 is a block diagram for explaining a configuration of an electronic device equipped with a wireless power receiver according to an embodiment of the present invention.
13 is a block diagram illustrating a configuration of a wireless power transmitter according to another embodiment of the present invention.
14 is a diagram for explaining a power control method using a duty rate of a pulse width modulation signal according to an embodiment of the present invention.
15 is a diagram for explaining a configuration of a power conversion circuit mounted in a wireless power transmitter 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.

In the description of the embodiment, in the case where it is described as being formed "above" or "below" each element, the upper or lower (lower) And that at least one further component is formed and arranged between the two components. Also, in the case of "upper (upper) or lower (lower)", it may include not only an upward direction but also a downward direction based on one component.

In the description of the embodiments, an apparatus equipped with a function of transmitting wireless power on a wireless charging system includes a wireless power transmitter, a wireless power transmitter, a wireless power transmitter, a wireless power transmitter, a transmitter, a transmitter, , A transmitting side, a wireless power transmission device, a wireless power transmitter, and the like are used in combination. Further, for the sake of convenience of explanation, it is to be understood that a wireless power receiving apparatus, a wireless power receiving apparatus, a wireless power receiving apparatus, a wireless power receiving apparatus, a receiving terminal, a receiving side, A receiver, a receiver, and the like can be used in combination.

The transmitter 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, a wall type, Power can also be transmitted. To this end, the transmitter may comprise at least one radio power transmission means. Here, the radio power transmitting means may be various non-electric power transmission standards based on an electromagnetic induction method in which a magnetic field is generated in a power transmitting terminal coil and charged using an electromagnetic induction principle in which electricity is induced in a receiving terminal coil under the influence of the magnetic field. Here, the wireless power transmission means may include an electromagnetic induction wireless charging technique defined by Wireless Power Consortium (WPC) and Power Matters Alliance (PMA), which are standard wireless charging technologies.

Also, a receiver according to an embodiment of the present invention may include at least one wireless power receiving means, and may receive wireless power from two or more transmitters at the same time. For example, the wireless power receiving means may include an electromagnetic induction wireless charging technique as defined in Wireless Power Consortium (WPC) and Power Matters Alliance (PMA), a wireless charging technology standard framework. As another example, the wireless power receiving means may include an electromagnetic resonance wireless charging technique defined in Alliance For Wireless Power (A4WP), a wireless charging technology standard framework. In yet another example, the wireless power receiving means may be configured to receive multiple defined multiples defined by the Airfuel Alliance, a standard defined to receive power adaptively at the same time or in any one way via the electromagnetic induction and electromagnetic resonance methods. Mode charging technique.

The receiver 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, A portable electronic device such as a toothbrush, an electronic tag, a lighting device, a remote control, a fishing rod, a smart watch, etc. However, the present invention is not limited thereto. It suffices.

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 transmission terminal 10 for wirelessly transmitting power, a wireless power receiving terminal 20 for receiving the transmitted power, and an electronic device 20 Lt; / RTI >

For example, the wireless power transmitting terminal 10 and the wireless power receiving terminal 20 can 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 transmitting terminal 10 and the wireless power receiving terminal 20 perform out-of-band communication in which information is exchanged using a different frequency band different from the operating frequency used for wireless power transmission .

For example, information exchanged between the wireless power transmitting terminal 10 and the wireless power receiving terminal 20 may include control information as well as status information of each other. Here, the status information and the control information exchanged between the transmitting and receiving end 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.

 For example, the unidirectional communication may be that the wireless power receiving terminal 20 transmits information only to the wireless power transmitting terminal 10, but the present invention is not limited thereto, and the wireless power transmitting terminal 10 may transmit information Lt; / RTI >

In the half duplex communication mode, bidirectional communication is possible between the wireless power receiving terminal 20 and the wireless power transmitting terminal 10, but information can be transmitted only by any one device at any time.

The wireless power receiving terminal 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 includes current reception sensitivity information, current power usage information, information for identifying an application being executed, CPU usage information, battery charge status information, battery output voltage / current information, and the like But is not limited to, information obtainable from the electronic device 30 and available for wireless power control. The wireless power receiving terminal 20 may transmit various status information of the obtained electronic device 30 to the wireless power transmitting terminal 10 through in-band communication or out-of-band communication.

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 receiving terminal 20 may include a plurality of wireless power receiving devices, and a plurality of wireless power receiving devices may be connected to one wireless power transmitting terminal 10, Charging may also be performed. At this time, the wireless power transmitting terminal 10 can distribute power to a plurality of wireless power receiving apparatuses in a time division manner, but it is not limited thereto. In another example, the wireless power transmitting terminal 10 can distribute power to a plurality of wireless power receiving apparatuses using different frequency bands allocated to the wireless power receiving apparatuses.

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 radio power transmitting terminal 10 may be composed of a plurality of radio power transmitting apparatuses. In this case, the wireless power receiving terminal 20 may be connected to a plurality of wireless power transmission apparatuses at the same time, and may simultaneously receive power from connected wireless power transmission apparatuses to perform charging. In this case, the number of wireless power transmission devices connected to the wireless power receiving terminal 20 is determined by the required power amount of the wireless power receiving terminal 20, the battery charging state, the power consumption amount of the electronic device, the available power amount of the wireless power transmission device, May be adaptively determined based on the reception sensitivity of the terminal equipped with the mobile terminal.

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 sender does not receive a response signal to the digital ping (e. G., A signal strength packet) from the receiver at step 420, then it may transition back to step 410 again at step 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 240, 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 the 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 receiving end by the digital ding signal transmitted by the transmitter, the receiver can modulate the received digital ding 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 packet 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 state transition diagram of a wireless power receiver supporting an electromagnetic resonance method according to an embodiment of the present invention.

6, the state of the wireless power receiver is largely divided into a disabled state 610, a boot state 620, an enabled state 630 (or an On state), and a system error state System Error State, 640).

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 activated state 630 may be divided into an optimum voltage state 631, a low voltage state 632, and a high voltage state 633 depending on the value of V _RECT .

The wireless power receiver in the deactivation state 610 may transition to the boot state 620 if the measured V _RECT value is greater than or equal to the predefined V _{RECT_BOOT} value.

In the boot state 620, 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 620 receives the V _RECT If it is confirmed that the required power at the lower end has been reached, the charging state can be shifted to the activated state 630 to start charging.

The wireless power receiver in the active state 630 may transition to the boot state 620 if it is confirmed that charging is complete or charging is interrupted.

In addition, the wireless power receiver in the active state 630 may transition to a system fault state 640 if a predetermined system fault 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 630 is a V _RECT If the value falls below the V _{RECT _BOOT} value, it may transition to the inactive state 610.

The wireless power receiver of the boot state 620 or system failure condition 640 may be shifted by, inactive 610 falls below the value V _RECT V _{RECT _BOOT} value.

Hereinafter, the state transition of the wireless power receiver within the active state 630 will be described in detail.

The operation region of the wireless power receiver according to the V _RECT in the electromagnetic resonance method will be described in detail.

V _RECT value is less than the predetermined V _{RECT _ BOOT,} the wireless power receiver is maintained in the inactive state (610).

When Thereafter, V _RECT value is increased above V _{RECT _BOOT,} the wireless power receiver and changes to the boot state 620, 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 630, the boot state 620 may begin charging the load.

If you, V _RECT value in the active state (630) exceeds a predetermined reference value of V _{RECT _MAX} for determining an over-voltage, the wireless power receiver may be a transition from the active state 630, a system error state 640.

Referring to FIG. 6, the active state 630 is divided into a low voltage state 632, an optimum voltage state 631, and a high voltage state 633 according to the value of V _RECT . .

Low voltage 632 _{V RECT _BOOT <= V RECT <} = V RECT _ means the _MIN state, and the optimum voltage state 631 means a state of V _{RECT _MIN} <V _RECT <= V _{RECT _ HIGH,} a high voltage state 633 may indicate the state _{RECT_HIGH} V <V _RECT <= V _{RECT _ MAX.}

In particular, the wireless power receiver transited to the high voltage state 633 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 hold time can be predetermined so as to prevent damage to the wireless power receiver and the load in the high-voltage state 633.

When the wireless power receiver transitions to the system error state 640, it may transmit a predetermined message indicating an overvoltage occurrence to the wireless power transmitter via 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 blocking means provided to prevent damage to the load due to the overvoltage in the system fault state 630. [ 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 when an overvoltage is generated in the wireless power receiver and transitioned to a system error state 640 has been described in the above embodiment, 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 640 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.

FIG. 7 is a state transition diagram for explaining a state transition procedure in a wireless power transmitter supporting an electric resonance system according to an embodiment of the present invention. Referring to FIG.

Referring to FIG. 7, the state of the wireless power transmitter is divided into a configuration state 710, a power save state 720, a low power state 730, a power transfer state 720, , 740, a Local Fault State 750, and a Latching Fault State 760.

When power is applied to the wireless power transmitter, the wireless power transmitter can transition to the configuration state 710. [ The wireless power transmitter may transition to a power saving state 720 when a predetermined reset timer expires in the configuration state 710 or the initialization procedure is completed.

In the power saving state 720, 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 start within a predetermined time after entering the power saving state 720. [ 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 720 transition.

In the power saving state 720, the wireless power transmitter periodically generates and transmits a first beacon sequence (first beacon sequence) for detecting the presence or absence of a conductive object on the charged area, and changes the impedance of the receiving resonator, Load Variation- can be detected.

Also, in the power saving state 720, the wireless power transmitter may periodically generate and transmit a predetermined second beacon sequence (Second Beacon Sequence) for identifying the sensed object. At this time, the transmission timing of the beacon may be determined such that the first beacon sequence and the second beacon sequence do not overlap with each other. Hereinafter, for convenience of explanation, the first beacon sequence and the second beacon sequence will be referred to as a short beacon sequence and a long beacon sequence, respectively.

In particular, the short beacon sequence can be transmitted is generated repeatedly with a conductive object, the standby power of the wireless power transmitter for a short interval so that it can be saved (t _{SHORT _BEACON)} a predetermined time interval (t _CYCLE) until it is detected on the charging area . For example, t _{SHORT _BEACON} is less than 30ms, t _CYCLE. However, each can be set to 250ms ± 5 ms but is not limited to this. Also, the current intensity of each short beacon included in the short beacon sequence is greater than a predetermined reference value, and can be gradually increased during a predetermined time period.

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

Also, in the power saving state 720, the wireless power transmitter periodically generates and transmits the second beacon sequence-that is, the long beacon sequence-to provide sufficient power for the booting and response of the wireless power receiver .

That is, when the wireless power receiver is booted through the long beacon sequence, it can broadcast an appropriate response signal over the out-of-band communication channel and transmit it to the wireless power transmitter.

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

Thereafter, the wireless power transmitter may wait for reception of a predetermined response signal during the long beacon transmission period, if the impedance change of the reception resonator is detected. Hereinafter, for convenience of explanation, the response signal is 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.

For example, the advertisement signal may include message identification information for identifying a message defined in the out-of-band communication standard, unique service identification information for identifying whether the wireless power receiver is legitimate or compatible with the wireless power transmitter, Information for identifying the category of the wireless power receiver, wireless power receiver authentication information, an overvoltage protection function, and an overvoltage protection function. 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 720 to a low power state 730 when an advertisement signal is received. 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.

If the wireless power transmitter transmits a predetermined control signal for initiating charging via out-of-band communication in the low power state 730, i.e., a predetermined control signal requesting the wireless power receiver to transmit power to the load, to the wireless power receiver, The state of the wireless power transmitter may transition from the low power state 730 to the power transfer state 740. [

If the out-of-band communication link establishment procedure or registration procedure in the low power state 730 is not normally completed, the state of the wireless power transmitter may transition from the low power state 730 to the power saving state 720. [

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 of 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 730 or the power transfer state 740, May be transitioned to power saving state 720. &lt; RTI ID = 0.0 &gt;

In addition, the wireless power transmitter in the low power state 730 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 730 may transition to the power saving state 720. [ 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 740, the wireless power transmitter may transition to a low power state 730 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 configuration state 710, local failure state 750, and lock failure state 760. [

In addition, the wireless power transmitter can dynamically control the transmit power based on state information received from the wireless power receiver in the power transmit state 740. [

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 may be configured to determine a power intensity to be received by a wireless power receiver based on at least one of the current available power, the priority of each wireless power receiver, May be adaptively determined. Here, the power intensity of each wireless power receiver can be determined, but not limited to, how much power should be received at a ratio of the maximum power that can be processed by the rectifier of the 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 based on 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 transmits predetermined receiver state information indicating whether or not the wireless power control is possible according to the power control command of the wireless power transmitter to the wireless power transmitter before receiving the power control command It is possible.

The power transmission state 740 may be in any one of a first state 741, a second state 742 and a third state 743 depending on the power reception state of the connected wireless power receiver.

In one example, the first state 741 may indicate that the power reception state of all the wireless power receivers connected to the wireless power transmitter is in a normal voltage state.

The second state 742 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 743 may indicate 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 a lock failure state 760 if a system error is detected in a power saving state 720 or a low power state 730 or a power transmission state 740. [

The wireless power transmitter in the lock fault condition 760 may transition to either a configuration state 710 or a power saving state 720 if all connected wireless power receivers are determined to have been removed from the charging area.

In addition, in the lock fault condition 760, the wireless power transmitter may transition to the local fault condition 750 if a local fault is detected. Here, the wireless power transmitter, which is the local failure state 750, may transition back to the lock failure state 760 once the local failure is released.

On the other hand, when transitioning from a state of either the configuration state 710, the power saving state 720, the low power state 730, or the power transfer state 740 to the local failure state 750, If it is released, it may transition to the configuration state 710.

The wireless power transmitter may shut off the power supplied to the wireless power transmitter if the wireless power transmitter transitions to the local failure state 750. [ For example, the wireless power transmitter may transition to a local fault condition 750 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 760 if the intensity of the output current of the transmit resonator is above a reference value. At this time, the wireless power transmitter that has transitioned to the lock failure state 760 may attempt to make the intensity of the output current of the transmission resonator less than a reference value for a predetermined time. Here, the attempt may be repeated for a predetermined number of times. If the lock failure state 760 is not released despite repeated execution, the wireless power transmitter transmits a predetermined notification signal indicating that the lock failure state 760 is not released to the user 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 760 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 repetitive execution, the lock failure state 760 is automatically released At which time the state of the wireless power transmitter may be automatically transitioned from the lockout state 760 to the power saving state 720 so that the detection and identification procedure for the wireless power receiver may be performed again.

The wireless power transmitter in the power transmission state 740 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.

8 is a flowchart illustrating a method of transmitting a wireless power in a wireless power transmitter according to an embodiment of the present invention.

Referring to FIG. 8, the wireless power transmitter may receive the reception sensitivity information (S810). Here, the reception sensitivity information may be information on reception sensitivity of the wireless communication signal measured by the electronic device on which the wireless power receiver identified by the wireless power transmitter is mounted. For example, the electronic device may include a smart phone, a notebook, and a drone equipped with wireless communication means. The wireless communication signal may include a predetermined reference signal transmitted from a base station and a repeater of the mobile communication system, for example, ) Signal - or may be a specific reference signal sent by a WiFi Access Point (AP). Here, the mobile communication system may include a Code Division Multiple Access (CDMA) system, a Wideband Code Division Multiple Access (WCDMA) system, and a Long Term Evolution (LTE) system. The reception sensitivity according to an exemplary embodiment of the present invention includes a received signal strength indicator (RSSI), a reference signal received power, a reference signal reception quality (RSRQ) Either the signal to interference plus noise ratio (SINR) may be used.

The wireless power transmitter may compare the received reception sensitivity with a predetermined reference value to determine whether the current reception sensitivity is less than a predetermined reference value (S820).

As a result of the determination, if the current reception sensitivity is less than the predetermined reference value, the wireless power transmitter can change the pulse width modulation (PWM) frequency (S830).

Generally, the wireless power transmitter must be able to adaptively control the strength of the transmitted power according to the requested power strength of the wireless power receiver. In particular, in the case of a system performing wireless charging using a fixed operating frequency, the power level of the output power can be controlled by controlling the voltage level and duty of the DC power applied from the power source. Hereinafter, for convenience of explanation, the power control method through the duty control will be referred to as a PWM power control method. At this time, a specific PWM frequency may be used for PWM power control. It should be noted that a PWM signal having the same duty has the same output power even if the applied frequency is different. However, the harmonic component (i.e., the harmonic component) generated according to the frequency applied to the PWM signal may be changed. At this time, some harmonic components may affect the wireless communication frequency band used in the electronic device on which the wireless power receiver is mounted. That is, some harmonic components may be interference or noise components in the wireless communication frequency band, which may deteriorate reception sensitivity in electronic devices. Therefore, when the reception sensitivity of the electronic device deteriorates below a certain level during wireless power charging, the harmonic component in the frequency plane can be shifted by adjusting the PWM frequency.

The wireless power transmitter may return to step 810 after changing the PWM frequency. Thereafter, when the received reception sensitivity exceeds a predetermined reference value, for example, the reception sensitivity may be equal to or greater than a specific set value, or may be within a predetermined range, the currently set PWM frequency may be maintained S840).

An electronic apparatus equipped with a wireless power receiver according to an embodiment of the present invention can transmit the reception sensitivity to the wireless power transmitter at predetermined intervals.

The electronic apparatus equipped with the wireless power receiver according to another embodiment of the present invention may transmit the reception sensitivity information at the current time to the wireless power transmitter only when the current reception sensitivity deviates from a predetermined reference value or the reception sensitivity changes by a predetermined reference value or more have.

A wireless power transmitter in accordance with one embodiment may receive receive sensitivity information from a wireless power receiver via in-band communication.

A wireless power transmitter in accordance with another embodiment may receive reception sensitivity information from a wireless power receiver via some out-of-band communication. For example, the out-of-band communication may be performed by a wireless communication system such as NFC (near field communication), Zigbee communication, infrared communication, visible light communication, Bluetooth communication, bluetooth low energy (BLE), ultrawideband Bi-directional communication.

The wireless power transmitter according to another embodiment may be equipped with a Wi-Fi communication function, in which case the reception sensitivity information may be received via the Wi-Fi AP.

The wireless power transmitter according to another embodiment may be equipped with a mobile communication function. In this case, the reception sensitivity information may be received through a mobile communication network.

9 is a flowchart illustrating a method of transmitting a wireless power in a wireless power transmitter according to another embodiment of the present invention.

Referring to FIG. 9, during wireless charging, the wireless power transmitter may receive reception sensitivity information (S910). Here, the reception sensitivity information may be received by any one of in-band communication, out-of-band communication, mobile communication network, and Wi-Fi network.

The wireless power transmitter can compare whether the reception sensitivity is less than a predetermined reference value (S920).

As a result of the comparison, if the reception sensitivity is smaller than the predetermined reference value, that is, if the reception sensitivity is not normal, the wireless power transmitter can transmit and transmit the power at the minimum possible intensity (S930).

In general, the wireless power receiver may terminate or reset the connection with the wireless power transmitter if power reception is not achieved for a period of time during the power transmission phase. Accordingly, the wireless power transmitter according to an exemplary embodiment of the present invention can transmit a minimum intensity power at which the connection to the wireless power receiver is terminated or the wireless power receiver is not reset, when the reception sensitivity is not normal.

The wireless power receiver can determine whether the reception sensitivity is improved by more than a predetermined level when the reception sensitivity information is received during power transmission to the minimum intensity (S950). Here, the determination as to whether the reception sensitivity is improved beyond a certain level may include a case where the reception sensitivity is compared with a predetermined normal determination reference value or a case where the reception sensitivity is within a predetermined normal range, but the present invention is not limited thereto.

If it is determined in step 950 that the reception sensitivity is not improved by more than a predetermined level, the wireless power transmitter can maintain the current pulse width modulation frequency (S960). That is, when the reception sensitivity is not changed from the abnormal state to the normal state even after the transmission power is reduced to the predetermined minimum power intensity, the wireless power transmitter determines that the reception sensitivity is not deteriorated by the harmonic component of the pulse width modulation frequency .

If it is determined in step 950 that the reception sensitivity is improved by more than a predetermined level, the wireless power transmitter may change the currently applied pulse width modulation frequency to another frequency (S970). That is, when the reception sensitivity is changed from the abnormal state to the normal state after the transmission power is reduced to the predetermined minimum power intensity, the wireless power transmitter can determine that the reception sensitivity is deteriorated by the harmonic component of the pulse width modulation frequency have.

The wireless power transmitter according to an exemplary embodiment of the present invention continuously monitors changes in reception sensitivity and adaptively changes the pulse width modulation frequency until reception sensitivity becomes normal. Of course, if a pulse-width modulated frequency with a normal receive sensitivity is detected, the wireless power transmitter can send power by maintaining the corresponding pulse-width modulated frequency.

In addition, after steps 960 and 970, the wireless power transmitter may adaptively control the transmission power based on the power control signal fed back from the wireless power receiver.

10 is a flowchart illustrating a method of transmitting a wireless power in a wireless power transmitter according to another embodiment of the present invention.

In general, frequency bands allocated to mobile communication providers are different, and accordingly, in the case of a dedicated mobile terminal for a specific mobile communication service provider, wireless communication is performed using the frequency band of the corresponding service provider. Therefore, the conventional wireless power transmitter can not confirm which frequency band the mobile terminal placed on the charging bed performs wireless communication.

In LTE communication systems, multicarrier transmission technology and Carrier Aggregation (CA: Carrier Aggregation), which is a technique to increase transmission speed by bundling heterogeneous frequency bands, are supported. Therefore, the frequency band used for wireless communication in the mobile terminal can be changed in real time.

Referring to FIG. 10, a wireless power transmitter according to an embodiment of the present invention may receive reception sensitivity information and wireless communication frequency allocation information (S1010). Here, the reception sensitivity information and the radio frequency allocation information may be received through a communication channel connected to the wireless power receiver, wherein the communication channel may be an in-band communication channel or an out-of-band communication channel, but is not limited thereto The wireless power transmitter according to another exemplary embodiment may receive at least one of the reception sensitivity information and the wireless communication frequency allocation information through a separate communication channel with the electronic device equipped with the wireless power receiver.

The wireless power transmitter can confirm whether the reception sensitivity is below a predetermined reference value (S1020).

If it is determined that the reception sensitivity is less than the predetermined reference value, the wireless power transmitter may change the current pulse width modulation frequency to a predetermined pulse width modulation frequency corresponding to the received wireless communication frequency allocation information (S 1030). For example, the pulse width modulation frequency to be changed for each allocated wireless communication frequency band may be defined in advance based on the preliminary experimental results, but is not limited thereto, and the predetermined frequency offset value may be added to the current pulse width modulation frequency After applying the new pulse width modulation frequency, the pulse width modulation frequency at which the reception sensitivity exceeds the predetermined reference value may be determined as the pulse width modulation frequency to be changed.

As a result of step 1020, if the reception sensitivity is not lower than the predetermined reference value, the wireless power transmitter can maintain the currently set pulse width modulation frequency.

11 is a block diagram of a wireless power transmitter in accordance with an embodiment of the present invention.

11, the wireless power transmitter 1100 may include at least one of a communication unit 1110, a determination unit 1120, a modification unit 1130, a control unit 1140, and a power transmission unit 1150 .

It should be noted that the components of the wireless power transmitter 1100 shown in FIG. 11 are not necessarily essential components, and some components may be changed / added / deleted.

The communication unit 1110 can receive the reception sensitivity information from the wireless power receiver. The communication unit 1110 can receive the reception sensitivity information from the wireless power receiver using either in-band communication or out-of-band communication.

The determination unit 1120 can determine whether the reception sensitivity is normal by comparing the received reception sensitivity with a predetermined reference value. Also, the determination unit 1120 can determine whether the pulse width modulation frequency is required to be changed according to the determination result of whether or not the reception sensitivity is normal. Also, the determination unit 1120 may determine whether to change the intensity of the transmission power with the minimum power level corresponding to the wireless power receiver according to the determination result of the normality of the reception sensitivity.

The changing unit 1130 may change the pulse width modulation frequency used for the current power transmission to a specific pulse width modulation frequency according to a predetermined control signal of the determination unit 1120. [ Here, the pulse width modulation frequency to be changed can be changed dynamically based on a preset frequency offset. For example, when the current pulse width modulation frequency is f_current, the frequency offset is f_offset, and the pulse width modulation frequency to be changed is f_new, the changing unit 1130 periodically increases or decreases f_current by f_offset until the reception sensitivity becomes normal, Can be determined, and the determined f_new can be applied as a new f_current.

If the reception sensitivity is not normal according to the predetermined control signal of the determination unit 1120, the control unit 1140 determines whether the minimum power corresponding to the radio power receiver is lower than the predetermined power It can be controlled to be sent out. If the reception sensitivity changes from abnormal to normal during the power transmission interval of the minimum intensity, the determination unit 1120 may determine that the pulse width modulation frequency should be changed according to the control signal of the controller 1140.

In addition, the controller 1140 can dynamically control the strength of power transmitted through the power transmitter 1150 based on predetermined status information of the wireless power receiver received through in-band communication or out-of-band communication. Here, the status information of the wireless power receiver may include requested power information, received power information, charging status information, various types of error information, and the like, but is not limited thereto.

The power transmitter 1150 can adjust the intensity of the power transmitted through the transmit coil according to the control signal of the controller 1140. To this end, the power transmitter 1150 includes a DC-DC converter for converting the level of the DC voltage supplied from the external power supply to a specific DC voltage level, An AC signal generator for generating an AC signal, and a transmission coil for transmitting the generated AC signal to the radio. At this time, the DC-DC converter can convert the intensity of the DC power using a pulse width modulation signal having a specific duty ratio. If the number of transmitting coils mounted in the power transmitting unit 1150 is plural, the power transmitting unit 1150 may further include a multiplexer configured to switch a transmitting coil for power transmission. For example, the AC signal generator may be implemented by a full bridge inverter or a half bridge inverter, but the present invention is not limited thereto.

A wireless power transmitter according to another embodiment of the present invention may be mounted on a vehicle. In this case, the communication unit 1100 may be equipped with in-vehicle communication means for communication with a controller mounted on the vehicle. Here, the in-vehicle communication means may include at least one of CAN (Controller Area Network) communication, LIN communication, Flexlay communication, and Ethernet communication.

12 is a block diagram for explaining a configuration of an electronic device equipped with a wireless power receiver according to an embodiment of the present invention.

A wireless power receiver according to an embodiment of the present invention may be integrally formed with an electronic device or may be detachably configured through a predetermined connector.

Referring to FIG. 12, the electronic device 1200 may include a first communication unit 1210, a reception sensitivity measurement unit 1220, and a wireless power receiver 1230.

The first communication unit 1210 can transmit and receive wireless signals to / from the electronic device 1200 and an external base station or an AP.

The reception sensitivity measurement unit 1220 can measure the reception sensitivity of a radio signal received through the first communication unit 1210. [

The reception sensitivity measurement unit 1220 may transmit information on the measured reception sensitivity to the wireless power receiver 1230 at predetermined intervals or whenever a specific event is generated.

For example, a specific event may occur when the measured reception sensitivity is out of a predetermined normal range, but the present invention is not limited thereto. In another example, the measured reception sensitivity may be lower than a predetermined reference value.

The wireless power receiver 1230 may include a second communication unit 1231, a control unit 1232, and a power receiving unit 1233.

The second communication unit 1231 can transmit / receive a control signal to / from the wireless power transmitter. To this end, the second communication unit 1231 may include a modulator for generating a signal to be transmitted to the wireless power transmitter and a demodulator for demodulating a signal received from the wireless power transmitter. The second communication unit 1231 may transmit / receive a control signal through the in-band communication, but the second communication unit 1231 is not limited thereto. For example, the second communication unit 1231 may be a two-way out- Lt; RTI ID = 0.0 &gt; and / or &lt; / RTI &gt;

The reception sensitivity information measured by the reception sensitivity measurement unit 1220 can be transmitted to the controller 1232. The second communication unit 1231 receives the predetermined control signal including the reception sensitivity information from the controller 1232, To a power transmitter.

The controller 1230 may periodically acquire the reception sensitivity information from the reception sensitivity measurement unit 1220 according to an embodiment of the present invention. In this case, the control unit 1230 may control the reception sensitivity information at that time to be transmitted to the wireless power transmitter through the second communication unit 1231 only when the reception sensitivity falls below a predetermined reference value.

The power receiving unit 1233 rectifies the received AC signal, converts the rectified DC signal into a predetermined DC signal required by the load, and transmits the DC signal to the load. As an example, the load may include a battery, a display, a voice output circuit, a main processor, and various sensors.

For this purpose, the power receiving unit 1233 includes a receiving coil for receiving the AC signal, a rectifier for converting the received AC signal into a DC signal, a DC-DC converter for converting the rectifier output voltage to a specific voltage required by the load . The power receiving unit 1233 may further include a matching unit (not shown) for performing impedance matching between the transmitting end and the receiving end.

The power receiving unit 1233 may further include a circuit for blocking overvoltage, overcurrent, and overheating in the wireless power receiver 1230 and a control module for controlling the circuit.

13 is a block diagram illustrating a configuration of a wireless power transmitter according to another embodiment of the present invention.

13, the wireless power transmitter 1300 includes a power conversion unit 1320, an AC power signal generation unit 1330, a multiplexing unit 1340, first to nth transmission coils 1350, a communication unit 1360, A pulse width modulation signal generation unit 1370, and a control unit 1380. The configuration of the wireless power transmitter 1300 is not necessarily an essential configuration, and may be configured to include more or less components.

The power conversion unit 1320 can convert the DC power supplied from the power supply unit 1310 according to the pulse width modulation signal input from the pulse width modulation signal generation unit 1370. At this time, And may be input to the power signal generator 1330.

The AC power signal generator 1330 may generate an AC power signal having a specific frequency by adding an AC component to the input DC power signal. For example, the AC power signal generator 1330 may include a full bridge circuit.

The multiplexer 1340 may transmit the AC power signal input from the AC power signal generator 1330 to the corresponding transmission coil according to the control signal of the controller 1380. For example, when the signal strength indicator packet corresponding to the digital ping signal transmitted for each transmission coil is demodulated and received by the communication unit 1360, the control unit 1380 outputs a signal strength indicator Based on the received signal strength indicator, a transmit coil to be used for wireless power transmission can be selected. Subsequently, the controller 1380 can control the multiplexer 1340 to transmit the AC power signal through the selected transmission coil.

13 illustrates a wireless power transmitter having a plurality of transmission coils. However, the wireless power transmitter according to another embodiment of the present invention may include one transmission coil . In this case, the multiplexer 1340 may be deleted from the configuration of the wireless power transmitter.

The communication unit 1360 can demodulate the control signal of the wireless power receiver through the in-band communication and transmit the demodulated result to the control unit 1380. The communication unit 1360 may also modulate the control packet received from the control unit 1380 and transmit the modulated signal to the multiplexing unit 1340. [

The wireless power transmitter 1300 according to an embodiment of the present invention may receive the measured reception sensitivity information at a terminal equipped with a wireless power receiver through in-band communication, but this is merely one embodiment, The wireless power transmitter 1300 according to the embodiment may further include an out-of-band communication function as well as an in-band communication function. In this case, the wireless power transmitter may receive the reception sensitivity information via the out-of-band communication channel. For example, the out-of-band communication may include short-range wireless communication such as Bluetooth communication, RFID communication, infrared communication, UWB (UltraWideBand) communication, and Zigbee communication.

The reception sensitivity information measured by the terminal may include at least one of strength information of a reference signal received from a mobile communication base station or a repeater or intensity information of a Wi-Fi signal received from a Wi-Fi AP. However, May include at least one of intensity information of a signal received from a communication / broadcasting satellite, reception intensity information of a GPS satellite signal, and intensity information of a terrestrial DMB signal. For example, the reference signal may be a pilot signal transmitted from the mobile communication base station, but is not limited thereto, and may be a reference signal for determining the signal reception sensitivity of the connected wireless communication network.

The control unit 1380 determines a duty ratio according to a power control signal fed back from the wireless power receiver and controls the pulse width modulation signal generator 1370 to generate a pulse width modulation signal corresponding to the determined duty rate can do. The intensity of the DC power transmitted to the AC power signal generator 1330 according to the duty rate will become more apparent through the description of FIG. 14 to be described later. For example, the power control signal may include a control error packet of the WPC standard, a power control signal of the PMA standard, for example, a PMA INC Signal, a PMA DEC Signal, , Dynamic Parameter Characteristic (Dynamic Parameter Characteristic) packet of A4WP, and the like.

The pulse width modulation signal generator 1370 may generate a pulse width modulation signal having a specific duty rate and a specific frequency according to a control signal of the controller 1380 and provide the pulse width modulation signal to the power converter 1320.

The harmonic component (harmonic component) generated when the pulse width modulated signal is generated in the pulse width modulated signal generator 1370 may be transmitted to the wireless power receiver to lower the reception sensitivity of the terminal.

At this time, when the frequency used for generating the pulse width modulation signal is changed to another frequency, the frequency band of the harmonic component is changed, and the reception sensitivity of the terminal can be restored to normal.

It should be noted that the intensity of the output power of the power converter 1320 is the same if the duty rate is the same regardless of the change in the frequency used for generating the pulse width modulation signal.

If the reception sensitivity of the terminal equipped with the wireless power receiver is changed from the abnormal state to the normal state through the frequency change for generating the pulse width modulation signal, the controller 1380 maintains the frequency corresponding to the normal state and outputs the pulse width modulation signal Width modulation signal generator 1370 so as to generate the pulse width modulation signal.

The wireless power transmitter 1300 according to another embodiment of the present invention includes an electromagnetic interference filter (EMI (Electromagnetic Interference Detector) 1300 configured to control a noise signal included in a power signal supplied from a power source 1310 to prevent damage to the internal components of the wireless power transmitter, Interference filter (not shown) may be additionally inserted between the power conversion unit 1310 and the power supply unit 1310.

14 is a diagram for explaining a power control method using a duty rate of a pulse width modulation signal according to an embodiment of the present invention.

In detail, FIG. 14 shows the change in the intensity of the output voltage in the power converter 1320 of FIG. 13 according to the duty rate change.

For example, if the input voltage Vin of the power conversion unit 1320 is 10V and the duty rate of the pulse width modulation signal is 30%, it can be seen that the output voltage of the power conversion unit 1320 is DC 3V.

In particular, it should be noted that if the duty rates are the same, the output voltage of the power converter 1320 is the same even if the frequency of the pulse width modulated signal is changed. Note, however, that when the frequency of the pulse width modulated signal changes at the same duty rate, the harmonic frequency component (harmonic component) also changes.

Therefore, when the reception sensitivity of the terminal equipped with the wireless power receiver falls below a predetermined reference value and the reception sensitivity is determined not to be normal, the wireless power transmitter according to the embodiment of the present invention is used for generating the pulse width modulation signal You can change the frequency. At this time, if it is confirmed that the reception sensitivity of the terminal is in a steady state according to the frequency change, the wireless power transmitter can generate the pulse width modulation signal using the finally changed frequency.

According to another embodiment of the present invention, when the reception sensitivity of a terminal equipped with a wireless power receiver falls below a predetermined reference value and it is determined that the reception sensitivity is not normal, the wireless power transmitter controls a duty cycle 1320 can be lowered. If the reception sensitivity of the terminal is changed to the steady state or the reception sensitivity is improved by more than a certain level after the output voltage is lowered, the wireless power transmitter can prevent the deterioration of reception sensitivity of the terminal due to the wireless charging - that is, the harmonic component of the pulse width modulation signal And the frequency used for generating the pulse width modulation signal can be changed to a predetermined offset unit. The frequency change can be repeatedly performed until it is confirmed that the reception sensitivity of the terminal is normal. The wireless power transmitter can generate a pulse width modulated signal by maintaining the last changed frequency when it is confirmed that the reception sensitivity of the terminal is normal according to the frequency change.

15 is a diagram for explaining a configuration of a power conversion circuit mounted in a wireless power transmitter according to an embodiment of the present invention.

15, the power conversion circuit includes a pulse width modulation signal generator 1501 for generating a pulse width modulation signal, a first switch 1503 for ON / OFF switching the input current according to the pulse width modulation signal, And a second capacitor 1504 and a first capacitor C1 and 1502 connected to the input voltage and an inductor L and a second capacitor 1506. The smoothing circuit And the like. Here, the pulse width modulation signal generator 1501 generates the pulse width modulation signal based on the duty ratio information determined according to the power control signal fed back from the wireless power receiver and the frequency information determined according to whether the terminal reception sensitivity is normal .

The pulse width modulation signal generator 1501 may monitor the output voltage and fine-tune it to the intensity of the desired output voltage.

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 (24)

A wireless power transmitter for wirelessly transmitting power to a wireless power receiver,
A communication unit for receiving information on reception sensitivity of a terminal equipped with the wireless power receiver;
A determination unit for determining whether the reception sensitivity of the terminal is normal by comparing the reception sensitivity with a predetermined reference value and determining whether to change the pulse width modulation frequency according to the determination result;
A changing unit for changing the frequency when the change of the pulse width modulation frequency is determined; And
A power transmitter for generating and transmitting power corresponding to the pulse width modulation signal generated at the changed frequency;
And a wireless power transmitter. The method according to claim 1,
Further comprising a control unit for determining whether the reception sensitivity is deteriorated by a harmonic component generated by the pulse width modulation frequency. 3. The method of claim 2,
If the reception sensitivity is not normal, the controller adjusts the intensity of the transmission power to a predetermined minimum power level. Then, when the reception sensitivity becomes normal, it is determined that the reception sensitivity is deteriorated by the harmonic component, Wireless power transmitter. The method of claim 3,
Wherein the control unit adjusts the duty rate of the pulse width modulation signal to control the intensity of the transmission power. The method according to claim 1,
Wherein the frequency is changed in units of a preset frequency offset until the reception sensitivity becomes normal. The method according to claim 1,
The information about the reception sensitivity includes a received signal strength indicator (RSSI), a reference signal received power (RSRP), a reference signal reception quality (RSRQ) And a signal to interference plus noise ratio (SINR). The method according to claim 1,
Wherein the information about the received sensitivity is received via an in-band communication. The method according to claim 1,
Wherein the information about the reception sensitivity is received over an established out-of-band communication channel with the wireless power receiver. The method according to claim 1,
Wherein the communication unit further receives information on a wireless communication frequency band allocated to the terminal, and a pulse width modulation frequency to be changed per wireless communication frequency band is preset and held. A wireless power receiver for receiving power from a wireless power transmitter wirelessly,
A controller for obtaining reception sensitivity information of a terminal equipped with the wireless power receiver;
A communication unit for transmitting the obtained reception sensitivity information to the wireless power transmitter; And
A power receiver for rectifying the received AC signal and delivering it to a load;
Wherein the AC signal generated with a pulse width modulation frequency dynamically determined according to the reception sensitivity information is received from the wireless power transmitter. A wireless charging method in a wireless power transmitter for wirelessly transmitting power to a wireless power receiver,
Receiving information on reception sensitivity of a terminal equipped with the wireless power receiver;
Comparing the reception sensitivity of the terminal with a predetermined reference value to determine whether it is normal;
Determining whether the pulse width modulation frequency is changed if the reception sensitivity is not normal;
Modifying the pulse width modulation frequency if the change in the pulse width modulation frequency is determined; And
Transmitting the generated power using the changed pulse width frequency
And the wireless charging method. 12. The method of claim 11,
Further comprising the step of determining whether the reception sensitivity is deteriorated by a harmonic component generated by the pulse width modulation frequency. 13. The method of claim 12,
Wherein the step of determining whether the reception sensitivity is deteriorated by the harmonic component
Adjusting the transmission power to a predetermined minimum power level if the reception sensitivity is not normal; And
Determining that the reception sensitivity due to the harmonic component has decreased when the reception sensitivity becomes normal during power transmission to the minimum power level
Wherein the pulse width modulation frequency is changed when a decrease in reception sensitivity due to the harmonic component is confirmed. 14. The method of claim 13,
Wherein the intensity of the transmission power is controlled by adjusting a duty rate of the pulse width modulation signal. 12. The method of claim 11,
The step of varying the pulse width modulation frequency
And modifying the pulse width modulation frequency by a preset frequency offset unit until the reception sensitivity becomes normal. 12. The method of claim 11,
The information about the reception sensitivity includes a received signal strength indicator (RSSI), a reference signal received power (RSRP), a reference signal reception quality (RSRQ) And a signal to interference plus noise ratio (SINR). 12. The method of claim 11,
Wherein the information about the reception sensitivity is received via in-band communication. 12. The method of claim 11,
Wherein the information about the reception sensitivity is received over an established out-of-band communication channel with the wireless power receiver. 12. The method of claim 11,
Further comprising receiving information on a wireless communication frequency band allocated to the terminal, wherein a pulse width modulation frequency to be changed per wireless communication frequency band is preset and maintained. A wireless charging method in a wireless power receiver that receives power wirelessly from a wireless power transmitter,
Obtaining reception sensitivity information of a terminal equipped with the wireless power receiver;
Transmitting the obtained received sensitivity information to the wireless power transmitter;
Rectifying the AC signal received through the receiving coil and transmitting the rectified AC signal to the load;
Wherein the AC signal generated with a pulse width modulation frequency dynamically determined according to the reception sensitivity information is received from the wireless power transmitter. 21. The method of claim 20,
And determining whether the wireless communication reception sensitivity of the terminal is normal based on the obtained reception sensitivity information. 22. The method of claim 21,
Wherein if the wireless communication reception sensitivity is not normal, the obtained reception sensitivity information is transmitted to the wireless power transmitter. 23. The method of claim 22,
Obtaining wireless communication frequency band information allocated to the terminal; And
Transmitting the obtained wireless communication frequency band information to the wireless power transmitter
Wherein the pulse width modulation frequency is determined at a predetermined frequency preset corresponding to the radio communication frequency band information. A computer-readable recording medium on which a program for executing the method according to any one of claims 11 to 23 is recorded.

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