KR20180125826A - Wireless Charging Method and Apparatus and System therefor - Google Patents

Abstract

The present invention relates to a wireless power transmission technology. Especially, the present invention relates to a wireless charging method and an apparatus and a system therefor. According to an embodiment of the present invention, the wireless charging method in a wireless power transmitter for wirelessly transmitting power to a wireless power receiver comprises: a step of charging with first guaranteed power; a step of determining whether a state is in a first charging power limit state while charging with the first guaranteed power; a power transmission contract changing step of changing from the first guaranteed power to second guaranteed power when the state is in the first charging power limit state; charging with the second guaranteed power; and determining whether the state is in a second charging power limit state while charging with the second guaranteed power.

Description

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

The present invention relates to wireless power transmission techniques and, more particularly, to a wireless charging method and apparatus and system therefor.

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

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

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

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

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

For example, the wireless power transmission scheme may be based on a variety of wireless power transmission standards based on an electromagnetic induction scheme in which a magnetic field is generated in a power transmitter coil and charged using an electromagnetic induction principle in which electricity is induced in a receiver coil under the influence of its magnetic field . Here, the electromagnetic induction type wireless power transmission standard may include an electromagnetic induction wireless charging technique defined by a Wireless Power Consortium (WPC) and an Air Fuel Alliance (formerly PMA, Power Matters Alliance).

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

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

On the other hand, as various devices are equipped with a wireless charging function and the intensity of power required for wireless charging is increased, the wireless power transmitter has problems such as reduction of the charging area due to high intensity output signal, heat generation, overvoltage and overcurrent .

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 yet another object of the present invention to provide a wireless charging method and apparatus and system therefor, in which a wireless power transmitter is capable of controlling charging power.

It is still another object of the present invention to provide a wireless charging method capable of controlling charging power according to the state of a wireless power transmitter, and a device and system therefor.

It is still another object of the present invention to provide a wireless charging method for enlarging a charging area during wireless charging and an apparatus and system therefor.

It is still another object of the present invention to provide a wireless charging method and apparatus and system therefor for improving a heating phenomenon of a wireless power transmitter.

It is still another object of the present invention to provide a wireless charging method for improving the overvoltage phenomenon of a wireless power transmitter and an apparatus and system therefor.

It is still another object of the present invention to provide a wireless charging method for improving the overcurrent phenomenon of a wireless power transmitter, and an apparatus and system therefor.

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

According to an aspect of the present invention, there is provided a wireless charging method in a wireless power transmitter for wirelessly transmitting power to a wireless power receiver, the wireless charging method comprising: performing charging in a second charging mode; Determining whether the first charging power limitation state is being performed during the charging in the second charging mode; A charging mode changing step of changing from the second charging mode to the first charging mode when the first charging power limitation state is established; Performing charging in a first charging mode; And determining whether the first charging mode is the second charging power limitation state during the charging operation in the first charging mode.

In addition, the wireless charging method according to the embodiment may further include stopping the power transmission if the second charging power limitation state is established.

Also, in the wireless charging method according to the embodiment, the first charging power limitation state may be a state in which the transmission power of the wireless power transmitter should be reduced to a predetermined intensity.

In the wireless charging method according to the embodiment, the transmission power of the wireless power transmitter may be 1 W or more and 6 W or less in the first charging mode.

Also, in the wireless charging method according to the embodiment, the first charging mode may be a low power charging mode and the second charging mode may be a high power charging mode.

In the wireless charging method according to an embodiment of the present invention, the step of determining whether the first charging power limitation state is in the first charging power limiting state includes: measuring transmission power; Receiving a received power packet including a received power value; Calculating a power loss value based on the measured transmission power and the received power value; And determining whether the calculated power loss value is equal to or greater than a first threshold power, and if the calculated power loss value is equal to or greater than the first threshold power, determining the first charging power limiting state.

In addition, in the wireless charging method according to the embodiment, the step of measuring the transmission power may include sensing a driving current or a driving voltage applied to a driving unit of the wireless power transmitter, and using the sensed driving current or driving voltage, Can be calculated.

Also, in the wireless charging method according to the embodiment, the power loss value may be the difference of the received power value at the measured transmission power.

In the wireless charging method according to the embodiment, the first threshold power may be 2000 mW or more and 4500 mW or less.

In the wireless charging method according to an embodiment of the present invention, the step of determining whether the first charging power limitation state is in the first charging power limitation state includes: measuring a driving current applied to a driving unit of the wireless power transmitter; And determining whether the measured driving current value is equal to or greater than a first threshold current, and if the measured driving current value is equal to or greater than the first threshold current, determining the first charging power limiting state.

In the wireless charging method according to the embodiment, the step of determining whether the first charging power limitation state is in the first charging power limit state includes: measuring a driving voltage applied to the driving unit of the wireless power transmitter; And determining whether the measured driving voltage value is equal to or greater than a first threshold voltage, and if the measured driving voltage value is equal to or greater than the first threshold voltage, determining the first charging power limiting state.

Further, in the wireless charging method according to the embodiment, the step of determining whether the first charging power limitation state is in the first charging power limitation state includes: measuring an internal temperature of the wireless power transmitter; And determining whether the measured internal temperature value is equal to or greater than the first threshold temperature, and if the measured internal temperature value is equal to or greater than the first threshold temperature, determining the first charging power limited state.

Further, in the wireless charging method according to the embodiment, the charging mode changing step may include: a power transmission interruption step; Reconnecting to the wireless power receiver; Receiving a packet for initial power control after a transition to a power transmission step; A first packet transfer step of informing a second charge mode support; A first response packet reception step of requesting a second charge mode; And ignoring the first response packet.

Further, in the wireless charging method according to the embodiment, the charging mode changing step may include: a power transmission interruption step; Reconnecting to the wireless power receiver; Receiving a packet for initial power control after a transition to a power transmission step; And not transmitting a first packet informing the second charging mode support.

According to another aspect of the present invention, there is provided a wireless charging method including: measuring a transmission power; receiving a reception power packet including a reception power value; Calculating a power loss value based on the measured transmission power and the received power value; And determining whether the calculated power loss value is equal to or greater than a second threshold power, and if the calculated power loss value is equal to or greater than the second threshold power, determining that the calculated power loss value is equal to or less than the second threshold power.

Also, in the wireless charging method according to the embodiment, the second threshold power may be a value smaller than the first threshold power.

In the wireless charging method according to the embodiment, the second threshold power may be 200 mW or more and 1400 mW or less.

In the wireless charging method according to an embodiment of the present invention, the step of determining whether the second charging power limitation state is a state includes: measuring a driving current applied to a driving unit of the wireless power transmitter; And determining whether the measured driving current value is equal to or greater than a second threshold current, and if the measured driving current value is equal to or greater than the second threshold current, determining the first charging power limiting state, The current may be a value smaller than the first threshold current.

In the wireless charging method according to the embodiment, the step of determining whether the second charging power is in the second charging power limit state includes the steps of: measuring a driving voltage applied to the driving unit of the wireless power transmitter; And determining whether the measured drive voltage value is equal to or greater than a second threshold voltage when the measured drive voltage value is greater than or equal to the second threshold voltage, The voltage may be a value less than the first threshold voltage.

According to another aspect of the present invention, there is provided a method of wireless charging, the method comprising: measuring an internal temperature of the wireless power transmitter; And determining whether the measured internal temperature value is equal to or higher than a second threshold temperature when the measured internal temperature value is equal to or higher than the second threshold temperature, The temperature may be a value less than the first threshold temperature.

A wireless charging method in a wireless power transmitter for wirelessly transmitting power to a wireless power receiver, the method comprising: performing charging at a first guaranteed power; Determining whether the first charging power limitation state is being performed during the charging operation with the first guarantee power; A power transfer contract changing step of changing from the first guarantee power to the second guarantee power when the first charging power limitation state is established; And performing charging with a second guaranteed power; And determining whether the second charging power limitation state is being performed during the charging operation with the second guarantee power.

In addition, the wireless charging method according to the embodiment may further include stopping the power transmission if the second charging power limitation state is established.

Also, in the wireless charging method according to the embodiment, the first charging power limitation state may be a state in which the transmission power of the wireless power transmitter should be reduced to a predetermined intensity.

Also, in the wireless charging method according to the embodiment, the second guaranteed power may be a power output of the wireless power transmitter of 1 W or more and 6 W or less.

Also, in the wireless charging method according to the embodiment, the first guaranteed power may be a high power and the second guaranteed power may be a low power.

In the wireless charging method according to an embodiment of the present invention, the step of determining whether the first charging power limitation state is in the first charging power limiting state includes: measuring transmission power; Receiving a received power packet including a received power value; Calculating a power loss value based on the measured transmission power and the received power value; And determining whether the calculated power loss value is equal to or greater than a first threshold power, and if the calculated power loss value is equal to or greater than the first threshold power, determining the first charging power limiting state.

In addition, in the wireless charging method according to the embodiment, the step of measuring the transmission power may include sensing a driving current or a driving voltage applied to a driving unit of the wireless power transmitter, and using the sensed driving current or driving voltage, Can be calculated.

Also, in the wireless charging method according to the embodiment, the power loss value may be the difference of the received power value at the measured transmission power.

In the wireless charging method according to the embodiment, the first threshold power may be 2000 mW or more and 4500 mW or less.

In the wireless charging method according to an embodiment of the present invention, the step of determining whether the first charging power limitation state is in the first charging power limitation state includes: measuring a driving current applied to a driving unit of the wireless power transmitter; And determining whether the measured driving current value is equal to or greater than a first threshold current, and if the measured driving current value is equal to or greater than the first threshold current, determining the first charging power limiting state.

In the wireless charging method according to the embodiment, the step of determining whether the first charging power limitation state is in the first charging power limit state includes: measuring a driving voltage applied to the driving unit of the wireless power transmitter; And determining whether the measured driving voltage value is equal to or greater than a first threshold voltage, and if the measured driving voltage value is equal to or greater than the first threshold voltage, determining the first charging power limiting state.

Further, in the wireless charging method according to the embodiment, the step of determining whether the first charging power limitation state is in the first charging power limitation state includes: measuring an internal temperature of the wireless power transmitter; And determining whether the measured internal temperature value is equal to or greater than the first threshold temperature, and if the measured internal temperature value is equal to or greater than the first threshold temperature, determining the first charging power limited state.

Further, in the wireless charging method according to the embodiment, the power transfer contract changing step may include: a power transmission interruption step; Reconnecting to the wireless power receiver; Receiving a generic request packet requesting a power transmitter capability packet for a post-transition power transfer contract to a negotiation phase; And transmitting a power transmitter capability packet including a second guaranteed power value in response to the general request packet.

Further, in the wireless charging method according to the embodiment, the power transfer contract changing step may include: receiving a received power packet from the wireless power receiver in a power transmitting step; Transmitting a NAK packet upon receiving the received power packet; Receiving a renegotiated packet from the wireless power receiver; Transmitting an ACK packet in response to the renegotiated packet; Receiving a generic request packet requesting a power transmitter capability packet for a post-transition power transfer contract to a renegotiation phase; And transmitting a power transmitter capability packet including a second guaranteed power value in response to the general request packet.

In the wireless charging method according to an embodiment of the present invention, the step of determining whether the second charging power is in the second charging power limit state includes: measuring transmission power; Receiving a received power packet including a received power value; Calculating a power loss value based on the measured transmission power and the received power value; And determining whether the calculated power loss value is equal to or greater than a second threshold power, and if the calculated power loss value is equal to or greater than the second threshold power, determining that the calculated power loss value is equal to or less than the second threshold power.

Also, in the wireless charging method according to the embodiment, the second threshold power may be a value smaller than the first threshold power.

In the wireless charging method according to the embodiment, the second threshold power may be 200 mW or more and 1400 mW or less.

In the wireless charging method according to an embodiment of the present invention, the step of determining whether the second charging power limitation state is a state includes: measuring a driving current applied to a driving unit of the wireless power transmitter; And determining whether the measured driving current value is equal to or greater than a second threshold current, and if the measured driving current value is equal to or greater than the second threshold current, determining the first charging power limiting state, The current may be a value smaller than the first threshold current.

In the wireless charging method according to the embodiment, the step of determining whether the second charging power is in the second charging power limit state includes the steps of: measuring a driving voltage applied to the driving unit of the wireless power transmitter; And determining whether the measured drive voltage value is equal to or greater than a second threshold voltage when the measured drive voltage value is greater than or equal to the second threshold voltage, The voltage may be a value less than the first threshold voltage.

According to another aspect of the present invention, there is provided a method of wireless charging, the method comprising: measuring an internal temperature of the wireless power transmitter; And determining whether the measured internal temperature value is equal to or higher than a second threshold temperature when the measured internal temperature value is equal to or higher than the second threshold temperature, The temperature may be a value less than the first threshold temperature.

A wireless power transmitter according to an embodiment includes a power transmitter including at least one transmission coil and a driver for controlling output power provided to the at least one transmission coil; A power converter for converting the intensity of the power applied from the outside to provide the output power; A communication unit for exchanging information with an external device; And a control unit for controlling a charging mode by transmitting a predetermined packet through the communication unit, wherein the charging mode includes a first charging mode and a second charging mode, and the controller performs charging in the second charging mode The control unit changes the charging mode to the first charging mode in the second charging mode when the first charging power limiting state is satisfied, 1 charge mode, the control unit may stop the power transmission if the second charge mode restriction canceled state is established.

Further, in the wireless power transmitter according to the embodiment, the first charging mode may be a low power charging mode and the second charging mode may be a high power charging mode.

Also, the wireless power transmitter according to the embodiment may further include a sensing unit, the sensing unit measures transmission power, and the communication unit receives a reception power packet including a reception power value, Wherein the controller calculates the power loss value based on the received power value, and the controller determines that the calculated power loss value is equal to or greater than the first threshold power, And the second threshold power may be a value less than the first threshold power if the second threshold power is greater than the second threshold power.

In addition, in the wireless power transmitter according to the embodiment, the first threshold power may be 2000 mW or more and 4500 mW or less, and the second threshold power may be 200 mW or more and 1400 mW or less.

Further, the wireless power transmitter according to the embodiment may further include a sensing unit having a current sensor, wherein the current sensor measures a driving current applied to the driving unit, and the control unit determines that the measured driving current value is a first threshold current The control unit determines that the measured charging current is equal to or greater than the first threshold current and the second threshold current is greater than the first threshold current, It can be a small value.

Further, the wireless power transmitter according to the embodiment may further include a sensing unit having a voltage sensor, wherein the voltage sensor measures a driving voltage applied to the driving unit, and the controller determines that the measured driving voltage value is a first threshold voltage The controller determines that the first charging power limit state is satisfied and the controller determines that the measured driving voltage value is equal to or greater than the second threshold voltage and determines that the second charging power limit state is greater than the first threshold voltage It can be a small value.

Further, the wireless power transmitter according to the embodiment may further include a sensing unit having a temperature sensor, wherein the temperature sensor measures an internal temperature of the wireless power transmitter, and the controller determines that the measured internal temperature value is equal to or higher than a first threshold temperature The controller determines that the first charging power limit state is satisfied and the controller determines that the measured internal temperature value is equal to or greater than the second threshold temperature, .

Further, the wireless power transmitter according to the embodiment is characterized in that the charging mode change is performed by a controller which reconnects with the wireless power receiver after a power transmission interruption in a second charging mode, and requests a second charging mode Lt; RTI ID = 0.0 > 1 < / RTI > response packet.

Further, the wireless power transmitter according to the embodiment is characterized in that the charging mode change is such that the control unit reconnects with the wireless power receiver after the power transmission stop in the second charging mode, and does not transmit the first packet informing the second charging mode support 1 < / RTI > charging mode.

In addition, the wireless power transmitter according to the embodiment may further include a display unit for displaying the charging performance information of the wireless power transmitter as an optical signal, wherein the display unit displays an optical signal indicating charging during the first charging mode, There may be differences in the optical signals to be displayed.

Further, the wireless power transmitter according to the embodiment may further include an acoustic output unit for outputting the charge execution information as an acoustic signal, and the acoustic output unit may include an acoustic signal output during charging in the first charge mode, There is a difference between the sound signals output during charging.

A wireless power transmitter according to an embodiment includes a power transmitter including at least one transmission coil and a driver for controlling output power provided to the at least one transmission coil; A power converter for converting the intensity of the power applied from the outside to provide the output power; A communication unit for exchanging information with an external device; And a control unit for transmitting a predetermined packet through the communication unit and changing a power transmission contract related to a guaranteed power as a power intensity value transmitted from the power transmitting unit in a power transmitting step, Wherein the control unit determines whether the first charging power limitation state is the first charging power limitation state when the charging is being performed with the first guarantee power and the control unit changes from the first guarantee power to the second guarantee power when the first charging power limitation state is satisfied And the control unit determines whether the second charging mode is the second charging mode or the second charging mode is in the second charging mode, Power transmission can be interrupted.

Further, in the wireless power transmitter according to the embodiment, the first guarantee power may be high power and the second guarantee power may be low power.

Also, the wireless power transmitter according to the embodiment may further include a sensing unit, the sensing unit measures transmission power, and the communication unit receives a reception power packet including a reception power value, Wherein the controller calculates the power loss value based on the received power value, and the controller determines that the calculated power loss value is equal to or greater than the first threshold power, And the second threshold power may be a value less than the first threshold power if the second threshold power is greater than the second threshold power.

In addition, in the wireless power transmitter according to the embodiment, the first threshold power may be 2000 mW or more and 4500 mW or less, and the second threshold power may be 200 mW or more and 1400 mW or less.

Further, the wireless power transmitter according to the embodiment may further include a sensing unit having a current sensor, wherein the current sensor measures a driving current applied to the driving unit, and the control unit determines that the measured driving current value is a first threshold current The control unit determines that the measured charging current is equal to or greater than the first threshold current and the second threshold current is greater than the first threshold current, It can be a small value.

Further, the wireless power transmitter according to the embodiment may further include a sensing unit having a voltage sensor, wherein the voltage sensor measures a driving voltage applied to the driving unit, and the controller determines that the measured driving voltage value is a first threshold voltage The controller determines that the first charging power limit state is satisfied and the controller determines that the measured driving voltage value is equal to or greater than the second threshold voltage and determines that the second charging power limit state is greater than the first threshold voltage It can be a small value.

Further, the wireless power transmitter according to the embodiment may further include a sensing unit having a temperature sensor, wherein the temperature sensor measures an internal temperature of the wireless power transmitter, and the controller determines that the measured internal temperature value is equal to or higher than a first threshold temperature The controller determines that the first charging power limit state is satisfied and the controller determines that the measured internal temperature value is equal to or greater than the second threshold temperature, .

Further, in the wireless power transmitter according to the embodiment, the charge mode change may be such that the control unit reconnects with the wireless power receiver after the power transmission interruption at the first guaranteed power, and transmits the power transmitter capability packet including the second guaranteed power value The charging can be performed with the second ensured power.

In addition, in the wireless power transmitter according to the embodiment, the charging mode change may include transmitting a NAK packet when receiving a received power packet in a power transmission step, transmitting an ACK packet upon receiving a renegotiated packet, And transmit the power transmitter capability packet including the power value to perform charging with the second guaranteed power.

In addition, the wireless power transmitter according to the embodiment may further include a display unit for displaying the charging performance information of the wireless power transmitter as an optical signal, wherein the display unit displays an optical signal indicating charging during the first charging mode, There may be differences in the optical signals to be displayed.

Further, the wireless power transmitter according to the embodiment may further include an acoustic output unit for outputting the charge execution information as an acoustic signal, and the acoustic output unit may include an acoustic signal output during charging in the first charge mode, There is a difference between the sound signals output during charging.

Effects of the wireless charging method and the apparatus and system for the same according to the present invention will be described as follows.

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

The present invention also allows the wireless power transmitter to control the charging power.

In addition, the present invention can control the charging power according to the state of the wireless power transmitter.

Further, the present invention can enlarge the charging region during wireless charging.

Further, the present invention can improve the heat generation phenomenon of the wireless power transmitter.

Further, the present invention can improve the overvoltage phenomenon of the wireless power transmitter.

Further, the present invention can improve the overcurrent phenomenon of the wireless power transmitter.

Further, the present invention can utilize the component elements defined in the published wireless power transmission standard, and can follow the already defined standard.

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

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. It is to be understood, however, that the technical features of the present invention are not limited to the specific drawings, and the features disclosed in the drawings may be combined with each other to constitute a new embodiment.
1 is a block diagram illustrating a wireless charging system according to an embodiment.
2 is a state transition diagram for explaining a first wireless power transmission procedure defined in the WPC standard;
3 is a state transition diagram for explaining a second wireless power transmission procedure defined in the WPC standard.
4 is a block diagram illustrating a structure of a wireless power transmitter according to an exemplary embodiment of the present invention.
FIG. 5 is a block diagram illustrating a structure of a wireless power receiver interworking with the wireless power transmitter according to FIG.
6 is a diagram for explaining a modulation and demodulation method of a wireless power signal according to an embodiment.
7 is a diagram for explaining a packet format according to an embodiment of the first wireless power transmission procedure.
8 is a diagram for explaining the types of packets that can be transmitted in a ping stage of a wireless power receiving apparatus according to an embodiment of the first wireless power transmission procedure.
9 is a diagram for explaining a message format of an identification packet according to an embodiment of the first wireless power transmission procedure.
10 is a diagram for explaining a message format of a configuration packet and a power control hold packet according to an embodiment of the first wireless power transmission procedure.
11 is a diagram for explaining the structure of a charge mode packet for requesting a charge mode change according to an embodiment of the first wireless power transmission procedure.
12 is a view for explaining a type of a packet that can be transmitted in a power transmission step and a message format thereof by a wireless power receiving apparatus according to an embodiment of the first wireless power transmission procedure.
FIG. 13 is a diagram of a charge mode state for explaining a charge mode change according to an embodiment.
14 is a diagram for explaining a wireless charging method in a wireless power transmitter according to an embodiment.
15 is a diagram for explaining a wireless charging method on a wireless charging system according to an embodiment.
16 is a diagram for explaining a wireless charging method in a wireless power transmitter according to another embodiment.
FIG. 17 is a view for explaining an embodiment of the first charging power limitation state determination of FIG. 16; FIG.
FIG. 18 is a diagram for explaining another embodiment of the first charging power limitation state determination of FIG.
FIG. 19 is a diagram for explaining another embodiment of the first charging power limitation state determination of FIG.
FIG. 20 is a diagram for explaining another embodiment of the first charging power limitation state determination of FIG. 16; FIG.
FIG. 21 is a diagram for explaining an embodiment of the charging mode change of FIG. 16 on the wireless charging system.
FIG. 22 is a diagram for explaining an embodiment of a charge mode charge mode change of FIG. 16 in a wireless power transmitter. FIG.
FIG. 23 is a diagram for explaining another embodiment of the charge mode change of FIG. 16 on the wireless charge system. FIG.
FIG. 24 is a diagram for explaining another embodiment of the charge mode charge mode change of FIG. 16 in the wireless power transmitter. FIG.
FIG. 25 is a diagram for explaining an embodiment of the second charging power limitation state determination of FIG. 16; FIG.
FIG. 26 is a diagram for explaining another embodiment of the second charging power limitation state determination of FIG. 16; FIG.
FIG. 27 is a diagram for explaining another embodiment of the second charging power limitation state determination of FIG. 16; FIG.
FIG. 28 is a diagram for explaining another embodiment of the second charging power limitation state determination of FIG. 16; FIG.
29 is a diagram for explaining a packet format according to an embodiment of the second wireless power transmission procedure.
30 is a diagram for explaining a signal strength packet according to an embodiment of the second wireless power transmission procedure.
31 is a diagram for explaining a power transmission end packet according to an embodiment of the second wireless power transmission procedure;
32 is a diagram for explaining a power control hold packet according to an embodiment of the second wireless power transmission procedure;
33 is a diagram for explaining a configuration packet according to an embodiment of the second wireless power transmission procedure.
34 is a diagram for explaining an identification packet and an extension identification packet according to an embodiment of the second wireless power transmission procedure;
FIG. 35 is a diagram for explaining a general request packet according to an embodiment of the second wireless power transmission procedure. FIG.
FIG. 36 is a diagram for explaining a special request packet according to an embodiment of the second wireless power transmission procedure. FIG.
37 is a diagram for explaining an FOD status packet according to an embodiment of the second wireless power transmission procedure.
38 is a diagram for explaining a control error packet according to an embodiment of the second wireless power transmission procedure.
39 is a diagram for explaining a renegotiated packet according to an embodiment of the second wireless power transmission procedure.
40 is a diagram for explaining a message format of an 8-bit received power packet according to an embodiment of the second wireless power transmission procedure.
41 is a diagram for explaining a 24-bit received power packet according to an embodiment of the second wireless power transmission procedure.
FIG. 42 is a diagram for explaining a message format of a charge state packet according to an embodiment of the second wireless power transmission procedure. FIG.
Figure 43 is a diagram for describing packets and power transmitter capability packets transmitted from a wireless power transmitter to a wireless power receiver in accordance with an embodiment of a second wireless power transmission procedure.
44 is a diagram for explaining a wireless charging method on a wireless charging system according to another embodiment.
45 is a diagram for explaining a wireless charging method in a wireless power transmitter according to another embodiment.
46 is a diagram for explaining an embodiment of the power transmission contract modification of FIG. 45 on the wireless charging system.
47 is a view for explaining an embodiment of a power transmission contract change of Fig. 45 in a wireless power transmitter; Fig.
48 is a diagram for explaining another embodiment of the power transfer contract modification of FIG. 45 on the wireless charging system.
FIG. 49 is a diagram for explaining another embodiment of the power transmission contract modification of FIG. 45 in the wireless power transmitter; FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an apparatus and various methods to which the embodiments 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.

The present invention is not necessarily limited to these embodiments, as long as all of the constituent elements of the embodiment are described as being combined or operated together. That is, within the scope of the present invention, all of the components may be selectively coupled to one or more of them. In addition, although all of the components may be implemented as one independent hardware, some or all of the components may be selectively combined to perform a part or all of the functions in one or a plurality of hardware. As shown in FIG. The codes and code segments constituting the computer program may be easily deduced by those skilled in the art. Such a computer program may be stored in a computer-readable storage medium, readable and executed by a computer, thereby realizing embodiments. As the storage medium of the computer program, a magnetic recording medium, an optical recording medium, a carrier wave medium, or the like may be included.

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

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

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

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

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

The wireless charging device according to the embodiment 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 may be transmitted to the device.

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

A mobile phone, a smart phone, a laptop computer, a digital broadcasting terminal, a PDA (Personal Digital Assistants), a PMP (Portable Multimedia Player), a navigation device, an MP3 player, The present invention can be applied to a portable electronic device such as a toothbrush, an electronic tag, a lighting device, a remote control, a fishing rod, etc. However, the present invention is not limited thereto. ), And the term terminal or device can be used in combination. A wireless power receiver according to another embodiment may also be mounted on a vehicle, an unmanned aerial vehicle, an air drone or the like.

A wireless power receiver according to an embodiment may include at least one wireless power transmission scheme and may receive wireless power from two or more wireless power transmitters at the same time. Here, the wireless power transmission scheme may include at least one of the electromagnetic induction scheme, the electromagnetic resonance scheme, and the RF wireless power transmission scheme. Particularly, the wireless power receiving means for supporting the electromagnetic induction method includes a wireless power consortium (WPC), which is a wireless charging technology standard organization, and an electromagnetic induction wireless charging technique defined by the Air Fuel Alliance (formerly PMA, Power Matters Alliance) . In addition, the wireless power receiving means supporting the electromagnetic resonance method may include a resonance wireless charging technique defined in the Air Fuel Alliance (formerly Alliance for Wireless Power) standard mechanism, a wireless charging technology standard organization.

Generally, a wireless power transmitter and a wireless power receiver that constitute a wireless power system can exchange control signals or information through in-band communication or Bluetooth low energy (BLE) communication. Here, the in-band communication and the BLE communication can be performed by a pulse width modulation method, a frequency modulation method, a phase modulation method, an amplitude modulation method, an amplitude and phase modulation method, and the like. For example, the wireless power receiver can transmit various control signals and information to the wireless power transmitter by generating a feedback signal by switching on / off the current induced through the reception coil in a predetermined pattern. The information transmitted by the wireless power receiver may include various status information including received power intensity information. At this time, the wireless power transmitter can calculate the charging efficiency or the power transmission efficiency based on the received power intensity information.

1 is a block diagram illustrating a wireless charging system according to an embodiment.

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 30 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 exemplary embodiment may acquire various status information of the electronic device 30. [ For example, the status information of the electronic device 30 may include current power usage information, information for identifying a running application, CPU usage information, battery charge status information, battery output voltage / current information, temperature information, But it is not limited to this, and information that can be acquired from the electronic device 30 and available for wireless power control suffices.

2 is a state transition diagram for explaining a first wireless power transmission procedure defined in the WPC standard;

Referring to FIG. 2, power transmission from a transmitter to a receiver according to a first wireless power transmission procedure of the WPC standard is largely divided into a selection phase 210, a ping phase 220, and a configuration phase 230, and a power transfer phase 240.

The selection step 210 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 210, 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 220 (S201). In the selection step 210, 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 220, the transmitter activates the receiver when an object is detected, and transmits a digital ping to identify whether the receiver is a WPC compliant receiver. If the transmitter does not receive a response signal to the digital ping (e.g., a signal strength indicator) from the receiver in step 220, then the transmitter may transition back to the selection step 210 (step S202). In addition, in the step 220, when the transmitter receives a signal indicating completion of power transmission from the receiver, that is, a charge completion signal, the transmitter may transition to the selection step 210 (S203).

Once the ping step 220 is complete, the transmitter may transition to an identification and configuration step 230 to collect receiver identification and receiver configuration and status information (S204).

In the identifying and configuring step 230, the transmitter determines whether a packet is received or unexpected, a desired packet is not received for 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 210 (S205).

Once the identification and configuration for the receiver is complete, the transmitter may transition to power transfer step 240, which transmits wireless power (S206).

In a power transfer step 240, the transmitter may receive an unexpected packet, a desired packet is not 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 210 can be transited (S207).

Also, in power transfer step 240, if the transmitter needs to reconfigure a power transfer contract based on transmitter state changes, etc., it may transition to identification and configuration step 230 (S208).

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.

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

Referring to FIG. 3, power transmission from a transmitter to a receiver according to a second wireless power transmission procedure of the WPC standard is largely divided into a selection phase 310, a ping phase 320, and Configuration Phase 330, a Negotiation Phase 340, a Calibration Phase 350, a Power Transfer Phase 360, and a Renegotiation Phase 370 .

The selection step 310 includes a step of transitioning, e.g., S302, S304, S308, S310, S312, 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 310, the transmitter may monitor whether an object is present on the interface surface. If the transmitter detects that an object has been placed on the interface surface, it can transition to the zipping step 320. In the selection step 310, the transmitter transmits an analog ping signal of a very short pulse and, based on the current change of the transmission coil or the primary coil, It is possible to detect whether or not there is an error.

If an object is sensed in the selection step 310, the wireless power transmitter may measure the quality factor of the wireless power resonant circuit, e.g., the transmit coil and / or the resonant capacitor for wireless power transmission.

 A wireless power transmitter may measure the inductance of a wireless power resonant circuit (e.g., a power transfer coil and / or a resonant capacitor).

The quality factor and / or inductance may be used in future negotiation step 340 to determine whether a foreign object is present.

In step 320, the transmitter wakes up the receiver and transmits a digital ping to identify whether the object is a wireless power receiver in step S301. If the transmitter does not receive a response signal to the digital ping (e. G., A signal strength packet) from the receiver at step 320, then it may transition back to step 310 again. If the transmitter receives a signal indicating completion of power transmission from the receiver (i.e., a charge completion packet) in the step 320, the flow may proceed to the selection step 310 (S302).

Once the ping step 320 is complete, the transmitter may transition to an identification and configuration step 330 for identifying the receiver and collecting receiver configuration and status information (S303).

In the identifying and configuring step 330, the transmitter determines whether a packet is received or unexpected, a desired packet is received for 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 310 (S304).

The transmitter may determine whether an entry to the negotiation step 340 is required based on the negotiation field value of the configuration packet received in the identification and configuration step 330. [

If it is determined that negotiation is required, the transmitter may enter the negotiation step 340 (S305). In the negotiation step 340, the transmitter may perform a predetermined FOD detection procedure.

On the other hand, if it is determined that the negotiation is not required, the transmitter may directly enter the power transmission step 360 (S306).

At negotiation step 340, the sender may receive a Foreign Object Detection (FOD) status packet including a reference quality factor value. Or a FOD state packet including a reference inductance value. Or a status packet including a reference quality factor value and a reference inductance value. At this time, the transmitter can determine a quality factor threshold for FO detection based on the reference quality factor value. The transmitter can determine the inductance threshold for FO detection based on the reference inductance value.

The transmitter can detect whether there is an FO in the fill area using the quality factor threshold for the determined FO detection and the currently measured quality factor value, e.g., the quality factor value measured prior to the ping step, Power transmission can be controlled according to the detection result. As an example, if FO is detected, power transmission may be interrupted, but is not limited to this.

The transmitter can detect whether there is an FO in the charging region using the inductance threshold for the determined FO detection and the currently measured inductance value - e.g., the inductance value measured before the ping phase - The power transmission can be controlled. As an example, if FO is detected, power transmission may be interrupted, but is not limited to this.

If FO is detected, the transmitter may return to the selection step 310 (S308). On the other hand, if no FO is detected, the transmitter may enter the power transfer step 360 via the correction step 350 (S307 and S309). In detail, if the FO is not detected, the transmitter determines the strength of the power received at the receiving end in the correcting step 350 and determines the power loss at the receiving end and the transmitting end to determine the strength of the power transmitted at the transmitting end Can be measured. That is, the transmitter can predict the power loss based on the difference between the transmitting power of the transmitting end and the receiving power of the receiving end in the correcting step (350). A transmitter according to one embodiment may compensate the threshold for FOD detection by reflecting the predicted power loss.

In the power transfer phase 360, 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 310 can be performed (S310).

Also, in power transfer step 360, if the transmitter needs to reconfigure the power transfer contract according to transmitter condition changes, it may transition to renegotiation step 370 (S311). At this time, if the renegotiation is normally completed, the transmitter may return to the power transmission step 360 (S313).

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.

If the renegotiation is not normally completed, the transmitter stops transmitting power to the receiver and may transition to the selection step 310 (S312).

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

4, the wireless power transmitter 400 includes a power conversion unit 410, a power transmission unit 420, a communication unit 430, a control unit 440, a sensing unit 450, a storage unit 470, A display unit 480, and an audio output unit 490. [ It should be noted that the configuration of the wireless power transmitter 400 described above is not necessarily an essential configuration, and may be configured to include more or less components.

As shown in FIG. 4, when the power is supplied from the power supply unit 460, the power conversion unit 410 may convert the power to a predetermined intensity.

For this, the power conversion unit 410 may include a DC / DC conversion unit 411 and an amplifier 412.

The DC / DC converting unit 411 may convert DC power supplied from the power supply unit 460 into DC power having a specific intensity according to a control signal of the controller 440.

The amplifier 412 can adjust the intensity of the DC / DC-converted power according to the control signal of the controller 440. For example, the control unit 440 may receive the power reception status information and / or the power control signal of the wireless power receiver through the communication unit 430 and may receive the power control information based on the received power reception status information and / So that the amplification factor of the amplifier 412 can be dynamically adjusted. For example, the power reception status information may include, but is not limited to, the intensity information of the rectifier output voltage, the intensity information of the current applied to the reception coil, and the like. The power control signal may include a signal for requesting power increase, a signal for requesting power reduction, and the like.

The power transmitting unit 420 may include a driving unit 421 and a transmitting coil 422.

The driving unit 421 may include a multiplexer (or a multiplexer) (not shown), a carrier generator (not shown) for generating a specific duty ratio and a specific duty ratio for power transmission. In one example, the carrier generator may generate a specific frequency for converting the output DC power of the amplifier 412 delivered via the multiplexer to AC power having a particular frequency. In one example, the AC signal generated by the carrier generator is mixed with the output of the multiplexer 621 to generate AC power. However, this is only an example, It should be noted that they may be mixed only or later.

The frequency of the AC power transmitted to each of the transmission coils according to the embodiment may be different from each other, and another embodiment may be implemented by using a predetermined frequency controller having a function of adjusting the LC resonance characteristic for each transmission coil differently The resonance frequency of each of the transmission coils may be the same or different.

4, the power transmitting unit 420 includes a multiplexer of the driving unit 421 for controlling the output power of the amplifier 412 to be transmitted to the transmitting coil, and a plurality of transmitting coils 422, 1 th to n th transmit coils.

The sensing unit 450 may include at least one of a current sensor, a voltage sensor, and a temperature sensor.

More specifically, the sensing unit 450 may measure the driving current of the DC-converted power at the power changing unit 410 using the current sensor, and provide the measured driving current to the controller 440. The sensing unit 450 may measure the driving voltage of the DC-converted power at the power changing unit 410 using the voltage sensor, and provide the driving voltage to the controller 440. Also, the sensing unit 450 may measure the internal temperature of the wireless power transmitter 400 to determine whether overheating occurs using the temperature sensor, and provide the measurement result to the controller 440.

For example, the control unit 440 may be configured to calculate the driving current value, the driving voltage value, and the internal temperature value measured by the sensing unit 450 in the power transmission step according to the first wireless power transmission procedure of FIG. It is possible to determine whether or not the state is the first charging power limitation state. In addition, the controller 440 may use the received power value of the wireless power receiver to determine the first charging power limit state. The charging mode has a first charging mode according to the power transfer contract and a second charging mode in which the intensity of the transmission power is larger than the first charging mode. A more detailed description of the charging mode will be given later. The first charging power limiting state may be a state in which the wireless power transmitter is constrained to perform charging at a specific charging power level. A more detailed description of the first charging power limiting state may be made by the wireless charging method of the wireless power transmitter described later. In addition, when the controller 440 determines the first charging power limitation state during the charging in the second charging mode, the controller 440 may change the charging mode to the first charging mode. A more detailed description of the charging mode change may be made by the wireless charging method of the wireless power transmitter described below. In addition, the controller 440 may control the operation of the first wireless power transmission process based on one or more values of the driving current value, the driving voltage value, and the internal temperature value measured by the sensing unit 450 in the power transmission step according to the first wireless power transmission procedure of FIG. It is possible to judge whether or not the state is the second charging power limitation state. In addition, the controller 440 may use the received power value of the wireless power receiver to determine the second charging power limit state. The second charging power limiting state may be a state in which the wireless power transmitter must stop transmitting power. A more detailed description of the second charging power limiting state may be made by the wireless charging method of the wireless power transmitter described later. In addition, when the controller 440 determines the second charging power limitation state during the charging in the first charging mode, the controller 440 can stop the power transmission.

As another example, the control unit 440 may be configured to calculate the driving power based on at least one of the driving current value, the driving voltage value, and the internal temperature value measured by the sensing unit 450 in the power transmission step according to the second wireless power transmission procedure of FIG. It is possible to determine whether or not the state is the first charging power limitation state. In addition, the controller 440 may use the received power value of the wireless power receiver to determine the first charging power limit state. That is, the first charging power limitation state determination method of another example may be the same as the first charging power limitation state determination method of the above example. The guaranteed power may be a power intensity value determined by the wireless power transmitter and the wireless power receiver to transmit upon wireless charging in the power transfer phase by a power transfer agreement. A detailed description of the guaranteed power will be given later. The first charging power limiting state may be a state limited to perform charging at a specific charging power level. A more detailed description of the first charging power limiting state may be made by the wireless charging method of the wireless power transmitter described later. In addition, when the controller 440 determines the first charging power limitation state during the charging operation with the first guarantee power having the relatively large guaranteed power value, the control unit 440 changes the power transmission contract change to the second guaranteed power whose guaranteed power value is relatively small Can be performed. A more detailed description of a power transfer contract change may be provided by the wireless charging method of the wireless power transmitter described below. In addition, the controller 440 may control the power of the mobile station based on at least one of the driving current value, the driving voltage value, and the internal temperature value measured by the sensing unit 450 in the power transmission step according to the second wireless power transmission procedure of FIG. It is possible to judge whether or not the state is the second charging power limitation state. In addition, the controller 440 may use the received power value of the wireless power receiver to determine the second charging power limit state. That is, the method for determining the second charging power limitation state of another example may be the same as the second charging power limitation state determination method described above. The second charging power limitation state may be a state in which the power transmission must be stopped. A more detailed description of the second charging power limiting state may be made by the wireless charging method of the wireless power transmitter described later. In addition, when the controller 440 determines that the second charging power limitation state is being performed during the charging operation with the second guarantee power, the controller 440 can stop the power transmission.

The storage unit 470 may store the threshold power, the threshold current, the threshold voltage, the critical temperature, and the like used for determining the first charging power limiting state or the second charging power limiting state. In addition, the storage unit 470 may store the first charging power limitation state information before reconnection, which is used to change the charging mode or the power transmission contract, and the like.

The display unit 480 can convert the information processed by the control unit 440 into an optical signal from an electrical signal and display the optical signal. More specifically, the display unit 480 can display the charging performance information of the wireless power transmitter 400 so that it can be visually recognized. For example, the display portion 480 may be an LED, but is not limited thereto. The charging information may be charging mode information in accordance with the first wireless power transmission procedure and may be guaranteed power information in accordance with the second wireless power transmission procedure. For example, the display unit 480 may emit a white LED when the wireless power transmitter 400 performs charging with the first charging mode or the second charging power. In addition, the display unit 480 may emit a blue LED when the wireless power transmitter 400 performs charging in the second charging mode or the first ensured power. Also, when the wireless power transmitter 400 stops transmitting power, the display unit 480 can emit a red LED. Accordingly, the present invention can visually indicate charging performance information of a wireless power transmitter. In addition, the present invention according to the embodiment can easily visualize the charging performance information and identify a problem occurring during wireless charging.

The sound output unit 490 can convert the information processed by the control unit 440 into an audio signal from an electric signal and output the audio signal. More specifically, the sound output unit 490 may output sound so that the charging performance information of the wireless power transmitter 400 may be audibly perceived. For example, the sound output section 490 may be a speaker. The charging information may be charging mode information in accordance with the first wireless power transmission procedure and may be guaranteed power information in accordance with the second wireless power transmission procedure. For example, the sound output unit 490 can be output when the wireless power transmitter 400 performs charging with the first charging mode or the second guarantee power, while halting generation and interruption of the beep sound. The sound output unit 490 may continuously output the occurrence of the beep sound when the wireless power transmitter 400 performs the charging with the second charge mode or the first guaranteed power. Also, the audio output unit 490 can stop the audio output when the wireless power transmitter 400 stops transmitting power. Therefore, the present invention according to the embodiment can display the charging performance information of the wireless power transmitter audibly. In addition, the present invention according to the embodiment can easily identify the problem occurring during wireless charging by audibly indicating the charging performance information.

The control unit 440 according to an exemplary embodiment may transmit power by time division multiplexing for each transmission coil when a plurality of wireless power receivers are connected. For example, in a wireless power transmitter 400, three wireless power receivers - i.e., first through third wireless power receivers - are identified via three different transmit coils, i.e., first through third transmit coils, respectively The control unit 440 controls the multiplexer of the driving unit 421 to control power to be transmitted through a specific transmission coil in a specific time slot. At this time, the amount of power transmitted to the corresponding wireless power receiver can be controlled according to the length of the time slot allocated for each transmission coil, but this is only one embodiment. The amplification rate of the amplifier 412 of the wireless power receiver may be controlled to control the transmission power of each wireless power receiver.

The control unit 440 may control the multiplexer of the driving unit 421 so that the sensing signals may be sequentially transmitted through the first through n'th transmission coils 422 during the first sensing signal sending procedure. At this time, the control unit 440 can identify the time at which the sensing signal is transmitted using the timer 455. When the sensing signal transmission time arrives, the controller 440 controls the multiplexer 421 to output a sensing signal It can be controlled to be transmitted. For example, the timer 450 may transmit a specific event signal to the control unit 440 at predetermined intervals during the ping transmission step. When the event signal is detected, the control unit 440 controls the multiplexer 421 to transmit the corresponding event signal It is possible to control the digital ping to be transmitted through the coil.

In addition, the control unit 440 transmits a predetermined transmission coil identifier for identifying a signal strength indicator (Signal Strength Indicator) through a transmission coil from the demodulation unit 432 during the first detection signal transmission procedure, Lt; / RTI > received signal strength indicator. In the second sensing signal transmission procedure, the controller 440 controls the multiplexer of the driving unit 421 so that the signal strength indicator can be transmitted through the transmission coil (s) Control. In another example, when there are a plurality of transmit coils in which the signal strength indicator is received during the first differential sense signal transmission procedure, the control unit 440 transmits the received transmit coil with the signal strength indicator having the largest value as the second differential sense signal In the procedure, the detection signal may be determined as the transmission coil to be transmitted first, and the multiplexer of the driving unit 421 may be controlled according to the determination result.

The modulator 431 modulates the control signal generated by the controller 440 and transmits the modulated signal to the driver 421. [ Here, the modulation scheme for modulating the control signal includes a frequency shift keying (FSK) modulation scheme, a Manchester coding modulation scheme, a phase shift keying (PSK) modulation scheme, a pulse width modulation scheme, A differential bi-phase modulation method, and the like.

The demodulator 432 can demodulate the detected signal and transmit the demodulated signal to the controller 440 when a signal received through the transmission coil is detected. Here, the demodulated signal includes a reception power indicator, a signal strength indicator, an identification indicator, a configuration indicator, an error correction (EC) indicator for power control during wireless power transmission, an end of charge indicator (EOC) / Overcurrent / overheat indicator, and the like, but it is not limited thereto, and various status information for identifying the status of the wireless power receiver may be included.

The demodulation unit 432 can identify which demodulated signal is received from which transmission coil, and provide the control unit 440 with a predetermined transmission coil identifier corresponding to the identified transmission coil.

 For example, the wireless power transmitter 400 may acquire the signal strength indicator through in-band communication using the same frequency used for wireless power transmission to communicate with the wireless power receiver.

In addition, the wireless power transmitter 400 can transmit wireless power using the transmit coil 422, as well as exchange various information with the wireless power receiver via the transmit coil 422. [ In another example, the wireless power transmitter 400 may further include a separate coil corresponding to each of the transmit coil 422 (i.e., first to n < th > transmit coils) It should be noted that it may also perform in-band communication with the receiver.

In the description of FIG. 4, the wireless power transmitter 400 and the wireless power receiver perform in-band communication. However, the wireless power transmitter 400 is only one embodiment, Directional communication through different frequency bands. For example, the near-end bi-directional communication may be any one of low-power Bluetooth communication, RFID communication, UWB communication, and Zigbee communication.

FIG. 5 is a block diagram illustrating a structure of a wireless power receiver interworking with the wireless power transmitter according to FIG.

5, the wireless power receiver 600 includes a receiving coil 610, a rectifier 620, a DC / DC converter 630, a load 640, a sensing unit 650, 660, and a main control unit 670, as shown in FIG. Here, the communication unit 660 may include at least one of a demodulation unit 661 and a modulation unit 662.

Although the wireless power receiver 600 shown in the example of FIG. 5 is shown as being capable of exchanging information with the wireless power transmitter 400 through in-band communication, this is only one embodiment, The communication unit 660 according to the embodiment may provide short-range bidirectional communication through a frequency band different from the frequency band used for wireless power signal transmission.

The AC power received via the receive coil 610 may be delivered to the rectifier 620. The rectifier 620 may convert the AC power to DC power and transmit it to the DC / DC converter 630. The DC / DC converter 630 can convert the intensity of the rectifier output DC power to a specific intensity required by the load 640 and then deliver it to the load 640. Also, the receiving coil 610 may be configured to include a plurality of receiving coils (i.e., first through n-th receiving coils). The frequency of the AC power transmitted to each of the reception coils (not shown) according to an embodiment may be different from each other, and another embodiment may include a predetermined frequency controller having a function of adjusting LC resonance characteristics for different reception coils The resonance frequencies of the respective receiving coils can be set differently.

The sensing unit 650 may measure the intensity of the DC power output from the rectifier 620 and may provide it to the main control unit 670. Also, the sensing unit 650 may measure the intensity of the current applied to the reception coil 610 according to the wireless power reception, and may transmit the measurement result to the main control unit 670. Also, the sensing unit 650 may measure the internal temperature of the wireless power receiver 600 and provide the measured temperature value to the main control unit 670.

The main control unit 670 may compare the measured rectifier output DC power with a predetermined reference value to determine whether an overvoltage is generated. As a result of the determination, when an overvoltage is generated, a predetermined packet indicating that an overvoltage has occurred can be generated and transmitted to the modulating unit 662. Here, the signal modulated by the modulating unit 662 can be transmitted to the wireless power transmitter through the receiving coil 610 or a separate coil (not shown).

The main control unit 670 can determine that the detection signal is received when the intensity of the rectifier output DC power is equal to or greater than a predetermined reference value. When receiving the detection signal, the signal intensity indicator corresponding to the detection signal is received by the modulation unit 662 To be transmitted to the wireless power transmitter.

The main control unit 670 determines that the power transmission is stopped when the intensity of the rectifier output DC power is equal to or less than a predetermined reference value. If any one of the signal strength packet, the configuration packet, and the identification packet is transmitted to the modulator 662, Lt; RTI ID = 0.0 > wireless power transmitter. ≪ / RTI >

The demodulation unit 661 demodulates the AC power signal between the reception coil 610 and the rectifier 620 or the DC power signal output from the rectifier 620 to identify whether or not the detection signal is received and outputs the identification result to the main control unit 670. [ As shown in FIG. At this time, the main control unit 670 may control the signal intensity indicator corresponding to the detection signal to be transmitted through the modulation unit 662. [

6 is a diagram for explaining a modulation and demodulation method of a wireless power signal according to an embodiment.

Hereinafter, a method of encoding a packet to be transmitted will be described in detail with reference to FIGS. 1 to 5. FIG.

Referring to FIG. 1, when the wireless power transmitter 10 or the wireless power receiver 20 does not transmit a specific packet, the wireless power signal is modulated with modulation having a specific frequency, May be an alternating current signal. On the other hand, when the wireless power transmitting terminal 10 or the wireless power receiving terminal 20 transmits a specific packet, the wireless power signal may be an alternating signal modulated by a specific modulation method, as shown in FIG. For example, the modulation scheme may include, but is not limited to, an amplitude modulation scheme, a frequency modulation scheme, a frequency and amplitude modulation scheme, a phase modulation scheme, and the like.

The binary data of the packet generated by the wireless power transmitting terminal 10 or the wireless power receiving terminal 20 may be subjected to differential bi-phase encoding as shown in reference numeral 720. [ Specifically, the differential two-stage encoding has two state transitions to encode data bit one and one state transition to encode data bit zero. That is, the data bit 1 is encoded such that the transition between the HI state and the LO state occurs at the rising edge and the falling edge of the clock signal, and the data bit 0 is at the rising edge of HI State and the LO state may be encoded to occur.

The encoded binary data may be subjected to a byte encoding scheme, as shown in FIG. Referring to reference numeral 730, a byte encoding technique according to an embodiment of the present invention includes a start bit and a stop bit for identifying a start and a type of a bitstream of an 8-bit encoded binary bitstream, , And a parity bit for detecting whether or not an error has occurred in the bitstream (byte).

7 is a diagram for explaining a packet format according to an embodiment of the first wireless power transmission procedure.

Referring to FIG. 7, a packet format 800 used for information exchange between the wireless power transmitting terminal 10 and the wireless power receiving terminal 20 includes a function of acquiring synchronization for demodulating the packet and identifying an accurate start bit of the packet A header (Header) 820 field for identifying a type of a message included in the packet, a preamble field 810 for transmitting a message (Message, 830) field and a checksum (840) field for identifying whether an error has occurred in the packet.

As shown in FIG. 7, the packet receiving end may identify the size of the message 830 included in the packet based on the header 820 value.

In addition, the header 820 may be defined for each step of the wireless power transmission procedure, and some of the header 820 values may be defined as different types of messages although they are the same value at different stages. For example, referring to FIG. 8, it should be noted that the header value corresponding to the end power transfer in the ping phase and the power transmission phase in the power transfer phase may be equal to 0x02.

The message 830 includes data to be transmitted at the transmitting end of the packet. For example, the data included in the message 830 field may be, but is not limited to, a report, a request, or a response to the other party.

The packet 800 according to another embodiment may further include at least one of transmitting end identification information for identifying a transmitting end that transmitted the packet and receiving end identifying information for identifying a receiving end to receive the packet. Here, the transmitter identification information and the receiver identification information may include IP address information, MAC address information, product identification information, and the like. However, the present invention is not limited thereto.

The packet 800 according to another embodiment may further include predetermined group identification information for identifying the receiving group when the packet is to be received by a plurality of apparatuses.

8 is a diagram for explaining the types of packets that can be transmitted in a ping stage of a wireless power receiving apparatus according to an embodiment of the first wireless power transmission procedure.

As shown in FIG. 8, in the step of pinging, the wireless power receiving apparatus can transmit a signal strength packet or a power transmission stop packet.

Referring to reference numeral 901 in FIG. 8, a message format of a signal strength packet according to an exemplary embodiment may be composed of a signal strength value having a size of 1 byte. The signal strength value may indicate the degree of coupling between the transmitting coil and the receiving coil and may be calculated based on the rectifier output voltage in the digital ping section, the open circuit voltage measured in the output blocking switch, Lt; / RTI > The signal strength value may range from a minimum of 0 to a maximum of 255 and may have a value of 255 if the actual measured value for a particular variable is equal to the maximum value of that variable (Umax).

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

Referring to reference numeral 902 in FIG. 8, the message format of the power transmission stop packet according to an exemplary embodiment may include an end power transfer code having a size of 1 byte.

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

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

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

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

Reconfiguration can be used when renegotiation is required for power transmission conditions.

No response can be used if the transmitter's response to the control error packet - meaning increasing or decreasing the strength of the power - is judged to be unhealthy.

The noise current, which is different from the overcurrent, can be used when the noise current value measured at the receiver exceeds the defined threshold value due to switching noise in the inverter.

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

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

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

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

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

Referring to reference numerals 1001 to 1002, if the extension indicator value is 0, the device identifier for the corresponding wireless power receiver may be a combination of manufacturer information and basic device identification information. On the other hand, if the extension indicator value is 1, the device identifier for the wireless power receiver may be a combination of manufacturer information, basic device identification information, and extended device identification information.

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

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

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

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

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

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

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

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

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

Referring to reference numeral 1102, the message format of the power control hold packet may be configured to include a power control hold time (T_delay). A plurality of power control hold packets may be transmitted during the identification and configuration phase. For example, up to seven power control pending packets may be transmitted. The power control hold time (T_delay) may have a value between a predefined power control hold minimum time (T_min: 5 ms) and a power control hold maximum time (T_max: 205 ms). The wireless power transmission apparatus can perform power control using the power control retention time of the power control retention packet last received in the identification and configuration step. Also, the wireless power transmission apparatus can use the T_min value as the T_delay value when the power control hold packet is not received in the identification and configuration step.

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

11 is a diagram for explaining the structure of a charge mode packet for requesting a charge mode change according to an embodiment of the first wireless power transmission procedure.

Referring to FIG. 11, the header value of the charging mode packet may be any one of undefined values of the packet header values defined in the current wireless charging standard. For example, the header value of the charge mode packet may be defined as 0x18, as shown in FIG. 8, but it should be noted that this is not necessarily the value for convenience of explanation.

The message size corresponding to the header value 0x18 may be one byte.

Information on the charging mode to be changed may be recorded in the message field of the charging mode packet. For example, referring to reference numeral 1210, if a change to the second charging mode during charging in the first charging mode is required, the wireless power receiver may transmit and write 0xff in the message field of the charging mode packet. On the other hand, when a change to the first charging mode during charging in the second charging mode is requested, the wireless power receiver can transmit and write 0x00 in the message field of the charging mode packet. The example shown in FIG. 1210 is for the purpose of helping understanding of the present invention, but the message value is not necessarily so defined.

12 is a view for explaining a type of a packet that can be transmitted in a power transmission step and a message format thereof by a wireless power receiving apparatus according to an embodiment of the first wireless power transmission procedure.

Referring to FIG. 12, in a power transmission step, a packet that can be transmitted by the wireless power receiving apparatus includes a control error packet (CEP), an end power transfer packet, a received power packet, A Charge Status Packet, a packet defined by the manufacturer, and the like.

Reference numeral 1301 denotes a message format of a control error packet composed of a 1-byte control error value. Here, the control error value may be an integer value ranging from -128 to +127. If the control error value is negative, the transmission power of the radio power transmission apparatus decreases, and if it is positive, the transmission power of the radio power transmission apparatus can be increased. If the control error value is 0, the output power of the wireless power transmitting apparatus may be increased or decreased. In particular, a control error packet (CEP) with a control error value of zero may be referred to as a stable control error packet.

Reference numeral 1302 denotes a message format of an End Power Transfer Packet configured by a 1-byte End Power Transfer Code.

Reference numeral 1303 denotes a received power packet of a received power packet including a 1-byte received power value. Here, the received power value may correspond to the average rectifier received power value calculated during a predetermined period. The actual received power amount Preceded can be calculated based on the maximum power and the power class included in the configuration packet 1301. [ As an example, the actual amount of power received can be calculated by (received power value / 128) * (maximum power / 2) * (10 power rating).

Reference numeral 1304 denotes a message format of a Charge Status Packet consisting of a 1-byte Charge Status Value. The charge state value may indicate the battery charge amount of the wireless power receiving device. For example, the charge state value 0 means a completely discharged state, the charge state value 50 may mean a 50% charge state, and the charge state value 100 may mean a full charge state. If the wireless power receiving device does not include a rechargeable battery or can not provide charge state information, the charge state value may be set to OxFF.

FIG. 13 is a diagram of a charge mode state for explaining a charge mode change according to an embodiment.

Referring to FIG. 13, the power transmission step 240 of FIG. 2 may include a first charging mode 1410 and a second charging mode 1420. For example, the first charging mode 1410 may be when charging is performed at a general low power. The second charging mode 1420 may be the case where charging is performed with high power.

The first charging mode 1410 and the second charging mode 1420 can be switched to each other when a predetermined condition is satisfied. In one example, the wireless power receiver may cause the wireless power transmitter to switch to the second charging mode 1420 when receiving a request to switch from the electronic device to the second charging mode 1420 during the charging operation in the first charging mode 1410 The charging mode can be changed by transmitting a predetermined packet. In another example, the wireless power receiver may also transmit a predetermined packet to the wireless power transmitter requesting a switch to the first charging mode 1410 when the battery charge level reaches a predetermined threshold during charging to the second charging mode 1420 have.

A wireless power transmitter in accordance with another embodiment may send power to a plurality of wireless power receivers. In this case, if the wireless power receiver is newly connected or disconnected from the existing wireless power receiver, it may perform the power redistribution procedure for the currently connected wireless power receiver (s). If the power redistribution is no longer able to provide high power to the wireless power receiver being recharged in the second charging mode, the wireless power transmitter transmits to the wireless power receiver a second charging mode 1420 in the first charging mode 1410 ) To the mobile station UE.

In the above embodiment, the charging mode is divided into the first charging mode 1410 and the second charging mode 1420. However, this is only one embodiment, and a new charging mode , Not shown) may be defined and added. For example, the second charging mode 1420 for fast charging may be subdivided into an intermediate power fast charging mode (not shown) and a high power fast charging mode (not shown). For example, an intermediate power fast charge mode (not shown) can deliver an average of 9W of power. The high power fast charge mode (not shown) can deliver an average of 15W of power. The present invention is not limited to the above example, and the intermediate power fast charge mode (not shown) and the high power fast charge mode (not shown) may be defined in other meanings.

The initial charging mode according to one embodiment may be determined through state information exchange or negotiation between the wireless power transmitter and the wireless power receiver in the identification and configuration step 230 of FIG.

For example, in the identifying and configuring step 230 of FIG. 2, the wireless power transmitter may send certain information to the wireless power receiver to identify whether it is a device capable of second charging mode support. At this time, the wireless power receiver can transmit a predetermined packet requesting the second charging mode to the wireless power transmitter when the wireless power receiver is a device capable of the second charging mode and the battery charging amount is less than a predetermined reference value. When the wireless power transmitter normally enters the power transmission stage, it can switch to the second charging mode at the request of the wireless power receiver to perform wireless charging.

The initial charging mode according to another embodiment may be determined in the power transmission step. As an example, the wireless power transmitter may enter the power transfer phase, if it receives an initial power control request packet (e.g., but not limited to a Control Error Packet defined in the WPC standard) 2 < / RTI > charging mode. When the wireless power receiver receives the first packet and it is confirmed that the connected wireless power transmitter supports the second charging mode, the wireless power receiver determines whether charging is started in the second charging mode, To the wireless power transmitter. That is, the initial charge mode may be determined based on the first response packet.

14 is a diagram for explaining a wireless charging method in a wireless power transmitter according to an embodiment.

Referring to FIG. 14, when the wireless power receiver enters the power transmission step, it can collect its own status information (i.e., receiver status information) (S1501).

The wireless power receiver may determine whether a charge mode change is required based on the collected receiver state information (S1503 through S1505).

In one example, the receiver status information may include battery charge status information. If the battery charge level drops below a predetermined reference value during charging in the first charging mode, the wireless power receiver may determine that switching to the second charging mode is necessary.

 In another example, the receiver status information may include information about CPU usage. If the power consumption of the wireless power receiver rapidly increases due to the CPU usage exceeding the predetermined reference value during the charging in the first charging mode, the wireless power receiver may determine that switching to the second mode is necessary.

In another example, the receiver status information may include application software and peripheral status information. For example, if the number of currently running application software exceeds a predetermined reference value, the wireless power receiver may determine that a switch to the second charging mode is necessary. For example, the peripheral device status information may include camera driving status information, flash driving status information, speaker driving status information, and the like. The wireless power receiver may determine whether a switch to the second charging mode is required based on the operating state of the peripheral device.

As a result of the determination, if the change of the charging mode is required, the wireless power receiver may generate a predetermined charging mode packet including the charging mode value to be changed and transmit the packet to the wireless power transmitter (S1507).

If it is not necessary to change the charging mode in step 1505, the wireless power receiver may return to step 1501. [

In the description of FIG. 14, it is described that the wireless power receiver determines whether to change the charging mode based on the receiver status information, but this is only one embodiment. In another example, When the switching to the specific charging mode is requested according to the selection of the predetermined user menu on the wireless terminal, the wireless terminal may generate a charging mode packet requesting switching to the charging mode and transmit the packet to the wireless power transmitter.

15 is a diagram for explaining a wireless charging method on a wireless charging system according to an embodiment.

15 is a flowchart for explaining a charging mode switching procedure on the wireless charging system.

15, the wireless power transmitter 1610 receives a first control error packet from the wireless power receiver 1620 after a transition from the identification and configuration phase to the power transfer phase, And transmit it to the wireless power receiver 1620 (S1601 to S1602). The wireless power receiver 1620 determines that the wireless power transmitter 1610 supports the second charging mode based on the received first packet and if it is a device capable of charging in the second charging mode, And transmits the first response packet to the wireless power transmitter 1610 (S1603).

The charging mode can be switched to the second charging mode and the charging can be started in the second charging mode (S1604). Here, although not shown, the charging mode may be changed after a predetermined charging mode change waiting time elapses when switching from the first charging mode to the second charging mode. The recharge mode change wait time may be predefined or determined by the wireless power receiver 1620 and then communicated to the wireless power transmitter 1610 via the first response packet. In the second charging mode, the charging power transmitted from the wireless power transmitter 1610 can be controlled by the control error packet of the wireless power receiver 1620 (S1605).

16 is a diagram for explaining a wireless charging method in a wireless power transmitter according to another embodiment.

Referring to FIG. 16, in the power transmission step, the wireless power transmitter can perform charging in the second charging mode (S1610).

It can be determined whether or not the state is the first charging power limitation state (S1620). The first charging power limiting state may be a state in which the wireless power transmitter is constrained to perform charging at a specific charging power level. More specifically, the first charging power limiting state may be a state in which the transmission power of the wireless power transmitter should be reduced to a predetermined intensity. The wireless power transmitter may also be in a first charging power limited state due to one or more predetermined events. As an example, the predetermined event may be that the power loss of the wireless charge due to misplacement of the transmitter of the wireless power transmitter and the receiver of the wireless power receiver occurs above the first threshold power. In this case, when the wireless power transmitter determines that the first charging power limitation state is established and reduces the transmission power intensity, the wireless charging area increases. Accordingly, the wireless power transmitter can reduce the power loss of the wireless charging and proceed with wireless charging normally. The determination of the first charging power limitation state using the power loss follows the description of FIG. 17 to be described later. In another example, the predetermined event may be that the power loss of the wireless charge due to foreign matter (FO) between the wireless power transmitter and the wireless power receiver occurs above the first threshold power. In this case, the wireless power transmitter may determine that the power loss of the wireless charging is still high by determining the first charging power limit state and decreasing the output power intensity. Therefore, the wireless power transmitter can accurately determine that there is foreign matter (FO). The determination of the first charging power limitation state using the power loss follows the description of FIG. 17 to be described later. In another example, the predetermined event may occur in the driver of the wireless power transmitter with an overcurrent greater than or equal to the first threshold current. In this case, the wireless power transmitter can determine the first charging power limitation state and reduce the transmission power intensity, thereby preventing the overcurrent. The determination of the first charging power limitation state using the driving current follows the description of Fig. 18 to be described later. In another example, the predetermined event may occur in the driver of the wireless power transmitter with an overvoltage above the first threshold voltage. In this case, the wireless power transmitter can determine the first charging power limitation state and reduce the transmission power intensity to prevent the overvoltage. The determination of the first charging power limitation state using the driving voltage follows the description of FIG. 19 to be described later. In another example, a given event may occur at a wireless power transmitter with a high temperature phenomenon above a first threshold temperature. In this case, the wireless power transmitter may determine the first charging power limitation state and decrease the transmission power intensity to improve the heat generation phenomenon. The determination of the first charging power limitation state using the internal temperature follows the description of FIG. 20 to be described later. More specifically, the first charging power limiting state may be a state in which the transmission power of the wireless power transmitter is reduced to an intensity of 1 W or more and 6 W or less. More specifically, the first charging power limitation state may be a state for transmitting the transmission power of the wireless power transmitter with an intensity of 5W.

If it is determined that the first charging power limitation state is established, the wireless power transmitter may perform a charging mode change to change from the second charging mode to the first charging mode (S1630). The wireless power transmitter according to another embodiment is less power-transfer contracted in the first charging mode than in the second charging mode. For example, the transmission power in the second charging mode may be 9W, and the transmission power in the first charging mode may be 5W. That is, the wireless power transmitter may determine the first charging power state and perform the charging mode change to reduce the transmission power. If it is determined that the state is not the first charging power limitation state, the wireless power transmitter can perform charging in the second charging mode of S1610.

After changing the charging mode, the wireless power transmitter can perform charging in the first charging mode (S1640). For example, when charging is performed in the first charging mode, the wireless power transmitter can transmit the transmission power with an intensity of 5W.

It can be determined whether or not the state is the second charging power limitation state (S1650). The second charging power limiting state may be a state in which the wireless power transmitter must stop transmitting power. More specifically, the second charging power limiting state may be a state in which the wireless power transmitter determines that the power transmission should be stopped during wireless charging in the first charging power limiting state. That is, since the wireless power transmitter lowers the strength of the transmitted power because it is in the first charging power limiting state, it determines whether to stop the power transmission by determining the second charging power limiting state. For example, power loss due to wireless charging due to miss alignment between the transmitter of the wireless power transmitter and the receiver of the wireless power receiver may occur, and the wireless power may be reduced by lowering the transmission power during the first charging power limiting state. In this case, the wireless power transmitter can determine the second charging power limitation state if the power loss of the wireless charging is equal to or greater than the second threshold power. The determination of the second charging power limitation state using the power loss follows the description of FIG. 25 to be described later. As another example, a power loss due to a foreign matter (FO) due to a foreign matter (FO) may occur between the wireless power transmitter and the wireless power receiver, so that the transmission power may be lowered during the first charging power limiting state to advance the wireless charging. In this case, the wireless power transmitter can determine the second charging power limitation state if the power loss of the wireless charging is equal to or greater than the second threshold power. The determination of the second charging power limitation state using the power loss follows the description of FIG. 25 to be described later. As another example, an overcurrent may be generated in the driving unit of the wireless power transmitter, and the wireless power may be reduced by lowering the transmission power during the first charging power limiting state. In this case, the wireless power transmitter can determine the second charging power limitation state if the driving current is equal to or greater than the second threshold current. The determination of the second charging power limitation state using the driving current is based on the twenty-sixth description to be described later. As another example, an overvoltage may be generated in the driving unit of the wireless power transmitter, and the wireless power may be reduced by lowering the transmission power during the first charging power limitation state. In this case, the wireless power transmitter can determine the second charging power limitation state if the driving voltage is equal to or higher than the second threshold voltage. Determination of the second charging power limitation state using the driving voltage follows the description of FIG. 27 to be described later. As another example, a high-temperature phenomenon may occur in the wireless power transmitter, and the wireless power may be reduced by lowering the transmission power during the first charging power limitation state. In this case, the wireless power transmitter can determine the second charging power limitation state if the internal temperature is equal to or higher than the second threshold temperature.

If it is determined that the second charging power limitation state is established, the wireless power transmitter may stop the power transmission (S1660). More specifically, the wireless power transmitter may stop the power transmission if the wireless power receiver determines that it is in the second charging power limit state even though the wireless power receiver does not request the power transmission interruption. If it is determined that the state is not the second charging power limitation state, the wireless power transmitter can perform charging in the first charging mode of S1640.

Thus, other embodiments may allow the wireless power transmitter to control the charging power. Still further, other embodiments may control the charging power according to the state of the wireless power transmitter. Further, another embodiment can enlarge the charging area during wireless charging. Further, another embodiment can improve the heat generation phenomenon of the wireless power transmitter. In addition, other embodiments may improve the overvoltage phenomenon of the wireless power transmitter. Further, other embodiments can improve the overcurrent phenomenon of the wireless power transmitter.

FIG. 17 is a view for explaining an embodiment of the first charging power limitation state determination of FIG. 16; FIG. That is, FIG. 17 illustrates a step S1620 of determining the first charging power limiting state of FIG. 16 according to an embodiment of the present invention in more detail. 17 may be an embodiment of a step S4520 of determining a first charging power limitation state of FIG. 45 to be described later.

Referring to FIG. 17, the first charging power limitation state determination of FIG. 16 may be performed in the step of the wireless power transmitter performing charging in the second charging mode. The first charging power limitation state determination of FIG. 45 may be performed in the step of performing charging at the first guaranteed power by the wireless power transmitter (S1701).

The wireless power transmitter can measure the transmission power (S1702). More specifically, the measurement of the transmission power can be performed using the driving current or the driving voltage applied to the driving unit 421. [ For example, the transmission power is measured by sensing the driving current applied to the driving unit 421 by the current sensor provided in the sensing unit 450 of FIG. 4, and by using the sensing resistance May be used to calculate the transmission power. As another example, the transmission power is measured by sensing the driving current applied to the driving unit 421 by the current sensor provided in the sensing unit 450 of FIG. 4, and by sensing the sensing voltage May be used to calculate the transmission power.

The wireless power transmitter may receive the received power packet from the wireless power receiver (S1703). The received power packet may include the received power value of the received power that the wireless power receiver is receiving.

The wireless power transmitter can calculate the power loss value using the measured transmission power and the received power value of the received power packet (S1704). The power loss value may be a difference between the transmission power value and the reception power value.

The wireless power transmitter can determine whether the power loss value is equal to or greater than the first threshold power (S1705). The first threshold power may be a value with a large power loss to proceed with wireless charging at a predetermined delivery power intensity. The first threshold power may be a predetermined loss power value. The first threshold power may be 2000 mW or more and 4500 mW or less. More specifically, the first threshold power may be 4200 mW.

If the power loss value is equal to or greater than the first threshold power, the wireless power transmitter can determine that the first charging power limitation state is present (S1706). In one example of the first charging power limit state, the wireless power transmitter may experience a power loss of wireless charge due to misplacement of the transmitter of the wireless power transmitter and the receiver of the wireless power receiver above the first threshold power. Another example of a first charging power limiting state is that a wireless power transmitter can cause a power loss of wireless charging due to foreign matter (FO) between the wireless power transmitter and the wireless power receiver to exceed the first threshold power.

If the power loss value is less than the first threshold power, the wireless power transmitter can determine that it is not in the first charging power limitation state (S1707).

If the wireless power transmitter determines that the first charging power limitation state is established, the wireless power transmitter may store the first charging power limitation state in the storage unit 470. 16, the wireless power transmitter can perform the charging mode change of S1630 of FIG. 16 by checking the first charging power limitation state. If it is determined that the wireless power transmitter is not in the first charging power limitation state, the wireless power transmitter can perform charging in the second charging mode in step S1610. In the case of determining the first charging power limitation state of FIG. 45, the wireless power transmitter can check the first charging power limitation state and perform the power transmission contract change of S4530 of FIG. 45. FIG. If it is determined that the wireless power transmitter is not in the first charging power limitation state, the wireless power transmitter can perform charging with the first guarantee power of S4510 (S1708).

FIG. 18 is a diagram for explaining another embodiment of the first charging power limitation state determination of FIG. That is, FIG. 18 illustrates the step S1620 of determining the first charging power limitation state of FIG. 16 according to another embodiment in more detail. 18 may be another embodiment of the step S4520 of determining a first charging power limitation state of FIG. 45 to be described later.

Referring to FIG. 18, the determination of the first charging power limitation state of FIG. 16 may be performed in the step of the wireless power transmitter performing charging in the second charging mode. The first charging power limitation state determination of FIG. 45 may be performed in a step of the wireless power transmitter performing charging with the first guaranteed power (S1801).

The wireless power transmitter can measure the driving current (S1802). More specifically, as shown in FIG. 4, the current sensor of the sensing unit 450 can sense the driving current applied to the driving unit 421.

The wireless power transmitter can determine whether the measured driving current value is equal to or greater than the first threshold current (S1803). The first threshold current may be an overcurrent value in the course of wireless charging with a predetermined delivery power intensity. Also, the first threshold current may be a predetermined current value.

If the measured driving current value is equal to or greater than the first threshold current, the wireless power transmitter can determine that the first charging power limitation state is present (S1804). As an example of the first charging power limitation state, in the wireless power transmitter, an overcurrent may be generated in the driving unit so that the driving current may be equal to or higher than the first threshold current.

If the measured driving current value is less than the first threshold current, the wireless power transmitter can determine that the first charging power limitation state is not satisfied (S1805).

If the wireless power transmitter determines that the first charging power limitation state is established, the wireless power transmitter may store the first charging power limitation state in the storage unit 470. 16, the wireless power transmitter can perform the charging mode change of S1630 of FIG. 16 by checking the first charging power limitation state. If it is determined that the wireless power transmitter is not in the first charging power limitation state, the wireless power transmitter can perform charging in the second charging mode in step S1610. In the case of determining the first charging power limitation state of FIG. 45, the wireless power transmitter can check the first charging power limitation state and perform the power transmission contract change of S4530 of FIG. 45. FIG. If it is determined that the wireless power transmitter is not in the first charging power limitation state, the wireless power transmitter can perform charging with the first guarantee power of S4510 (S1806).

FIG. 19 is a diagram for explaining another embodiment of the first charging power limitation state determination of FIG. That is, FIG. 19 illustrates a step S1620 of determining the first charging power limitation state of FIG. 16 according to still another embodiment. Further, Fig. 19 may be another embodiment of the step S4520 for determining the first charging power limitation state of Fig. 45 to be described later.

Referring to FIG. 19, the first charging power limitation state determination of FIG. 16 may be performed in the step of the wireless power transmitter performing charging in the second charging mode. The determination of the first charging power limitation state of FIG. 45 may be performed in the step of the wireless power transmitter performing the charging with the first guaranteed power (S1901).

The wireless power transmitter can measure the driving voltage (S1902). More specifically, as shown in FIG. 4, the voltage sensor of the sensing unit 450 can sense the driving voltage applied to the driving unit 421.

The wireless power transmitter can determine whether the measured driving voltage value is equal to or greater than the first threshold voltage (S1903). The first threshold voltage may be an overvoltage value in the course of wireless charging with a predetermined delivery power intensity. Also, the first threshold voltage may be a predetermined voltage value.

If the measured driving voltage value is equal to or greater than the first threshold voltage, the wireless power transmitter can determine that the first charging power limitation state is present (S1904). As an example of the first charging power limitation state, the wireless power transmitter may generate an overvoltage at the driving unit so that the driving voltage may be equal to or higher than the first threshold voltage.

If the measured driving voltage value is less than the first threshold voltage, the wireless power transmitter can determine that the wireless terminal is not in the first charging power limitation state (S1905).

If the wireless power transmitter determines that the first charging power limitation state is established, the wireless power transmitter may store the first charging power limitation state in the storage unit 470. 16, the wireless power transmitter can perform the charging mode change of S1630 of FIG. 16 by checking the first charging power limitation state. If it is determined that the wireless power transmitter is not in the first charging power limitation state, the wireless power transmitter can perform charging in the second charging mode in step S1610. In the case of determining the first charging power limitation state of FIG. 45, the wireless power transmitter can check the first charging power limitation state and perform the power transmission contract change of S4530 of FIG. 45. FIG. If it is determined that the wireless power transmitter is not in the first charging power limitation state, the wireless power transmitter can perform charging with the first guarantee power of S4510 (S1906).

FIG. 20 is a diagram for explaining another embodiment of the first charging power limitation state determination of FIG. 16; FIG. That is, FIG. 20 illustrates the step S1620 of determining the first charging power limitation state of FIG. 16 according to another embodiment in more detail. 20 may be another embodiment of the step S4520 of determining the first charging power limitation state of FIG. 45 to be described later.

Referring to FIG. 20, the determination of the first charging power limit state of FIG. 16 may be performed in the step of the wireless power transmitter performing charging in the second charging mode. The determination of the first charging power limit state of FIG. 45 may be performed in the step of the wireless power transmitter performing the charging with the first guaranteed power (S2001).

The wireless power transmitter can measure the internal temperature (S2002). More specifically, as shown in FIG. 4, the temperature sensor of the sensing unit 450 can sense the internal temperature of the wireless power transmitter.

The wireless power transmitter may determine whether the measured internal temperature value is equal to or greater than the first threshold temperature (S2003). The first threshold temperature may be a high temperature value in the course of wireless charging at a given delivery power intensity. Further, the first threshold temperature may be a predetermined temperature value.

If the measured internal temperature value is equal to or higher than the first threshold temperature, the wireless power transmitter can determine that the first charging power limitation state is present (S2004). As an example of the first charging power limitation state, the wireless power transmitter may generate a heating phenomenon in the wireless power transmitter so that the internal temperature may be equal to or higher than the first threshold temperature.

If the measured internal temperature value is less than the first threshold temperature, the wireless power transmitter can determine that the first charging power limitation state is not satisfied (S2005).

If the wireless power transmitter determines that the first charging power limitation state is established, the wireless power transmitter may store the first charging power limitation state in the storage unit 470. 16, the wireless power transmitter can perform the charging mode change of S1630 of FIG. 16 by checking the first charging power limitation state. If it is determined that the wireless power transmitter is not in the first charging power limitation state, the wireless power transmitter can perform charging in the second charging mode in step S1610. In the case of determining the first charging power limitation state of FIG. 45, the wireless power transmitter can check the first charging power limitation state and perform the power transmission contract change of S4530 of FIG. 45. FIG. If it is determined that the wireless power transmitter is not in the first charging power limitation state, the wireless power transmitter can perform charging with the first guarantee power of S4510 (S2006).

FIG. 21 is a diagram for explaining an embodiment of the charging mode change of FIG. 16 on the wireless charging system.

Referring to FIG. 21, the wireless power transmitter 2110 during the charging in the second charging mode may stop the power transmission when determining the first charging power limitation state (S2101). Thereafter, the wireless power transmitter 2110 may proceed with the first wireless power transmission procedure in the order of the selection step, the ping step, the identification and configuration step, and the power transmission step.

The wireless power transmitter 2110 generates a predetermined first packet informing of the second charging mode support when the first control error packet is received from the wireless power receiver 2120 after the transition from the identification and configuration step to the power transmission step, (S2102 to S2103).

The wireless power receiver 2120 may determine that the wireless power transmitter 2110 supports the second charging mode based on the received first packet and if it is a device capable of charging in the second charging mode, And transmits the first response packet to the wireless power transmitter 2120 (S2104).

The wireless power transmitter 2110 may ignore the received first response packet (S2105). That is, the wireless power transmitter 2110 can continue wireless charging in the first charging mode even if it receives a predetermined first response packet that is requested in the second charging mode. Also, the wireless power transmitter 2110 may use the first charging power limitation state information stored in the storage unit 470 to perform step S2105.

FIG. 22 is a diagram for explaining an embodiment of a charge mode charge mode change of FIG. 16 in a wireless power transmitter. FIG.

Referring to FIG. 22, FIG. 22 illustrates step S1630 of performing the charge mode change of FIG. 16 according to an embodiment in more detail.

The charging mode change of S1630 can be performed when the wireless power transmitter determines that the first charging power limitation state is in operation in the second charging mode (S2201).

The wireless power transmitter may stop power transmission (S2202). That is, the wireless power transmitter may cause the wireless power transmitter to stop transmitting the charging power that is being wirelessly charged, even if the wireless power receiver does not request to stop transmitting power.

The wireless power transmitter may reconnect with the wireless power receiver (S2203). That is, the wireless power transmitter may reconnect with the wireless power receiver to proceed with wireless charging after aborting the power transmission. Reconnection may proceed in the order of a selection step, a ping step, an identification and configuration step, and a power transmission step in accordance with the first wireless power transmission procedure.

The wireless power transmitter may generate and send to the wireless power receiver a predetermined first packet indicating that the second charging mode is supported if a packet for initial power control after the transition is received from the wireless power receiver to the power transmission step (S2204 - S2205).

The wireless power transmitter may receive a first response packet requesting a second charging mode (S2206).

The wireless power transmitter may continue to charge the first charging mode (S2207 to S2208) while ignoring the first response packet requesting the second charging mode. The wireless power transmitter ignoring the first response packet may mean that it does not perform charging in the second charging mode until the first charging power limit state is ended. In addition, the wireless power transmitter may continue wireless charging in the first charging mode without entering the second charging mode based on the first charging power limitation state information stored in the storage unit 470 before the power transmission is stopped. That is, if the wireless power transmitter receives the first response packet requesting the second charging mode when the first charging power limitation state is before the power transmission is stopped, the wireless power transmitter can continue charging in the first charging mode. S2208 may be S1640 of Fig.

The charging mode change may be terminated by entering the step S1640 of FIG. 16 by ignoring the first response packet and charging in the first charging mode (S2209).

FIG. 23 is a diagram for explaining another embodiment of the charge mode change of FIG. 16 on the wireless charge system. FIG.

Referring to FIG. 23, if the wireless power transmitter 2310 is determined to be in the first charging power limitation state during the charging in the second charging mode, the power transmission may be stopped (S2301). Thereafter, the wireless power transmitter 2310 may proceed with the first wireless power transmission procedure in the order of the selection step, the ping step, the identification and configuration step, and the power transmission step.

The wireless power transmitter 2310 sends a first packet that informs the second charging mode support after receiving the first control error packet from the wireless power receiver 2320 after the transition from the identification and configuration step to the power transfer stage to the wireless power receiver 2320 (S2302 to S2303). That is, the wireless power transmitter 2310 can continue wireless charging in the first charging mode without transmitting the first packet informing of the second charging mode support. Also, the wireless power transmitter 2310 may use the first charging power limitation state information stored in the storage unit 470 to perform step S3103.

FIG. 24 is a diagram for explaining another embodiment of the charge mode charge mode change of FIG. 16 in the wireless power transmitter. FIG.

Referring to FIG. 24, FIG. 24 illustrates step S1630 of performing the charge mode change of FIG. 16 in accordance with another embodiment in more detail.

The charging mode change of S1630 can be performed when the wireless power transmitter determines that the first charging power limitation state is in operation in the second charging mode (S2401).

The wireless power transmitter may interrupt power transmission (S2402). That is, the wireless power transmitter may cause the wireless power transmitter to stop transmitting the charging power that is being wirelessly charged, even if the wireless power receiver does not request to stop transmitting power.

The wireless power transmitter may reconnect with the wireless power receiver (S2403). That is, the wireless power transmitter may reconnect with the wireless power receiver to proceed with wireless charging after aborting the power transmission. Reconnection may proceed in the order of a selection step, a ping step, an identification and configuration step, and a power transmission step in accordance with the first wireless power transmission procedure.

The wireless power transmitter may receive a packet for initial power control after the transition from the wireless power receiver to the power transmission step (S2404).

The wireless power transmitter may continue charging in the first charging mode without transmitting the first packet informing of the second charging mode support (S2405 to S2406). The fact that the wireless power transmitter has received the packet for initial power control but does not transmit the first packet informing of the second charging mode support means that the charging is not performed in the second charging mode until the first charging power limitation state is ended Lt; / RTI > In addition, the wireless power transmitter may continue wireless charging in the first charging mode without entering the second charging mode based on the first charging power limitation state information stored in the storage unit 470 before the power transmission is stopped. That is, the wireless power transmitter can continue charging in the first charging mode without charging in the second charging mode if the first charging power limitation state is before the power transmission is stopped. S2406 may be S1640 in Fig.

The charging mode change may be terminated by entering the step S2406 of FIG. 16 by charging the first charging mode without transmitting the first packet (S2407).

FIG. 25 is a diagram for explaining an embodiment of the second charging power limitation state determination of FIG. 16; FIG. That is, FIG. 25 illustrates a step S1650 of determining the second charging power limitation state of FIG. 16 according to an embodiment of the present invention in more detail. 25 may be an embodiment of a step (S4550) of determining a second charging power limitation state of FIG. 45 to be described later.

Referring to FIG. 25, the determination of the second charging power limit state of FIG. 16 may be performed in the step of the wireless power transmitter performing charging in the first charging mode. The determination of the second charging power limitation state of FIG. 45 may be performed in the step of the wireless power transmitter performing the charging with the second guaranteed power (S2501).

The wireless power transmitter may measure the transmit power (S2502). More specifically, the measurement of the transmission power can be performed using the driving current or the driving voltage applied to the driving unit 421. [ For example, the transmission power is measured by sensing the driving current applied to the driving unit 421 by the current sensor provided in the sensing unit 450 of FIG. 4, and by using the sensing resistance May be used to calculate the transmission power. As another example, the transmission power is measured by sensing the driving current applied to the driving unit 421 by the current sensor provided in the sensing unit 450 of FIG. 4, and by sensing the sensing voltage May be used to calculate the transmission power.

The wireless power transmitter may receive the received power packet from the wireless power receiver (S2503). The received power packet may include the received power value of the received power that the wireless power receiver is receiving.

The wireless power transmitter can calculate the power loss value using the measured transmission power and the received power value of the received power packet (S2504). The power loss value may be a difference between the transmission power value and the reception power value.

The wireless power transmitter can determine whether the power loss value is equal to or greater than the second threshold power (S2505). The second threshold power may be a value having a large power loss for proceeding wireless charging with a predetermined sending power intensity. The second threshold power may be a predetermined loss power value. Further, the second threshold power may be a value smaller than the first threshold power. The second threshold power may be 200 mW or more and 1400 mW or less. More specifically, the first threshold power may be 1000 mW.

If the power loss value is equal to or greater than the second threshold power, the wireless power transmitter can determine that the second charging power limitation state is satisfied (S2506). In one example of a second charging power limiting state, the wireless power transmitter may experience a power loss of wireless charging beyond the second threshold power due to misplacement of the transmitter of the wireless power transmitter and the receiver of the wireless power receiver. That is, even though the charging power limiter is determined to be in the first charging power limit state and the transmission power is lowered to expand the charging region of the wireless power transmitter, the degree of erroneous placement is large and the power loss of the wireless charging is large. Another example of the second charging power limiting state is that the wireless power transmitter can cause a power loss of wireless charging due to foreign matter (FO) between the wireless power transmitter and the wireless power receiver to exceed the second threshold power.

If the power loss value is less than the second threshold power, the wireless power transmitter may determine that the wireless terminal is not in the second charging power limitation state (S2507). In a case where the second charging power limitation state is not established, for example, a power loss occurs due to a misalignment between the transmitting section of the wireless power transmitter and the receiving section of the wireless power receiver, thereby lowering the transmission power during the first charging power limiting state, Charging can proceed. In this case, since the wireless power transmitter has a wider charging area, the power loss of the wireless charging may be reduced and the lost power value may be less than the second threshold power.

In the case of determining the second charging power limitation state in Fig. 16, when the wireless power transmitter determines that the second charging power limitation state is established, the wireless power transmitter can stop the power transmission in S1660 of Fig. If it is determined that the wireless power transmitter is not in the second charging power limitation state, the wireless power transmitter can perform charging in the first charging mode of S1640. In the case of determining the second charging power limitation state of FIG. 45, when the wireless power transmitter determines that the second charging power limitation state is established, the wireless power transmitter can stop the power transmission of S4560 of FIG. If it is determined that the wireless power transmitter is not in the second charging power limitation state, the wireless power transmitter may perform charging with the second guarantee power of S4540 (S2508).

FIG. 26 is a diagram for explaining another embodiment of the second charging power limitation state determination of FIG. 16; FIG. That is, FIG. 26 illustrates the step of determining (S1650) the second charging power limitation state of FIG. 16 according to another embodiment in more detail. 26 may be another embodiment of the step S4550 for determining the second charging power limitation state of FIG. 45 to be described later.

Referring to FIG. 26, the determination of the second charging power limit state of FIG. 16 may be performed in the step of the wireless power transmitter performing the charging in the first charging mode. The determination of the second charging power limit state of FIG. 45 may be performed in the step of the wireless power transmitter performing the charging with the second guaranteed power (S2602).

The wireless power transmitter can measure the driving current (S2602). More specifically, as shown in FIG. 4, the current sensor of the sensing unit 450 can sense the driving current applied to the driving unit 421.

The wireless power transmitter can determine whether the measured driving current value is equal to or greater than the second threshold current (S2603). The second threshold current may be an overcurrent value in the course of wireless charging with a predetermined delivery power intensity. Also, the second threshold current may be a predetermined current value. Further, the second threshold current may be a value smaller than the first threshold current.

If the measured driving current value is equal to or greater than the second threshold current, the wireless power transmitter can determine that the second charging power limitation state is present (S2604). As an example of the second charging power limitation state, the wireless power transmitter may generate an overcurrent in the driving unit so that the driving current may be equal to or higher than the second threshold current.

If the measured driving current value is less than the second threshold current, the wireless power transmitter may determine that the second charging power limitation state is not satisfied (S2605).

In the case of determining the second charging power limitation state in Fig. 16, when the wireless power transmitter determines that the second charging power limitation state is established, the wireless power transmitter can stop the power transmission in S1660 of Fig. If it is determined that the wireless power transmitter is not in the second charging power limitation state, the wireless power transmitter can perform charging in the first charging mode of S1640. In the case of determining the second charging power limitation state of FIG. 45, when the wireless power transmitter determines that the second charging power limitation state is established, the wireless power transmitter can stop the power transmission of S4560 of FIG. If it is determined that the wireless power transmitter is not in the second charging power limitation state, the wireless power transmitter can perform charging with the second guarantee power of S4540 (S2606).

FIG. 27 is a diagram for explaining another embodiment of the second charging power limitation state determination of FIG. 16; FIG. That is, FIG. 27 illustrates the step of determining (S1650) the second charging power limitation state of FIG. 16 according to another embodiment in more detail. Further, Fig. 27 may be another embodiment of the step S4550 for determining the second charging power limitation state of Fig. 45, which will be described later.

Referring to FIG. 27, the determination of the second charging power limit state of FIG. 16 may be performed in the step of the wireless power transmitter performing the charging in the first charging mode. The determination of the second charging power limit state of FIG. 45 may be performed in the step of the wireless power transmitter performing the charging with the second guaranteed power (S2701).

The wireless power transmitter can measure the driving voltage (S2702). More specifically, as shown in FIG. 4, the voltage sensor of the sensing unit 450 can sense the driving voltage applied to the driving unit 421.

The wireless power transmitter can determine whether the measured driving voltage value is equal to or greater than a second threshold voltage (S2703). The second threshold voltage may be an overvoltage value in the course of wireless charging with a predetermined delivery power intensity. Also, the second threshold voltage may be a preset voltage value. Further, the second threshold voltage may be a value smaller than the first threshold voltage.

If the measured driving voltage value is equal to or greater than the second threshold voltage, the wireless power transmitter can determine that the second charging power limitation state is present (S2704). As an example of the second charging power limitation state, the wireless power transmitter may generate an overvoltage at the driving unit, and the driving voltage may be higher than the second threshold voltage.

If the measured driving voltage value is less than the second threshold voltage, the wireless power transmitter can determine that the wireless terminal is not in the second charging power limitation state (S2705).

In the case of determining the second charging power limitation state in Fig. 16, when the wireless power transmitter determines that the second charging power limitation state is established, the wireless power transmitter can stop the power transmission in S1660 of Fig. If it is determined that the wireless power transmitter is not in the second charging power limitation state, the wireless power transmitter can perform charging in the first charging mode of S1640. In the case of determining the second charging power limitation state of FIG. 45, when the wireless power transmitter determines that the second charging power limitation state is established, the wireless power transmitter can stop the power transmission of S4560 of FIG. If it is determined that the wireless power transmitter is not in the second charging power limitation state, the wireless power transmitter can perform charging with the second guarantee power of S4540 (S2706).

FIG. 28 is a diagram for explaining another embodiment of the second charging power limitation state determination of FIG. 16; FIG. That is, FIG. 28 illustrates the step of determining (S1650) the second charging power limitation state of FIG. 16 according to another embodiment in more detail. 28 may be another embodiment of the step S4550 for determining the second charging power limitation state of FIG. 45 to be described later.

Referring to FIG. 28, the determination of the second charging power limitation state of FIG. 16 may be performed in the step of charging the wireless power transmitter in the first charging mode. The determination of the second charging power limit state of FIG. 45 may be performed in the step of the wireless power transmitter performing the charging with the second guaranteed power (S2801).

The wireless power transmitter can measure the internal temperature (S2802). More specifically, as shown in FIG. 4, the temperature sensor of the sensing unit 450 can sense the internal temperature of the wireless power transmitter.

The wireless power transmitter can determine whether the measured internal temperature value is equal to or higher than a second threshold temperature (S2803). The second threshold temperature may be a high temperature value as the wireless charging proceeds with a predetermined delivery power intensity. Further, the second critical temperature may be a predetermined temperature value. Further, the second threshold temperature may be a value smaller than the first threshold temperature.

If the measured internal temperature value is equal to or higher than the second threshold temperature, the wireless power transmitter can determine that the second charging power limitation state is present (S2804). As an example of the second charging power limitation state, the wireless power transmitter may generate a heating phenomenon in the wireless power transmitter so that the internal temperature may be higher than the second threshold temperature.

If the measured internal temperature value is less than the second threshold temperature, the wireless power transmitter can determine that it is not in the second charging power limitation state (S2805).

In the case of determining the second charging power limitation state in Fig. 16, when the wireless power transmitter determines that the second charging power limitation state is established, the wireless power transmitter can stop the power transmission in S1660 of Fig. If it is determined that the wireless power transmitter is not in the second charging power limitation state, the wireless power transmitter can perform charging in the first charging mode of S1640. In the case of determining the second charging power limitation state of FIG. 45, when the wireless power transmitter determines that the second charging power limitation state is established, the wireless power transmitter can stop the power transmission of S4560 of FIG. If it is determined that the wireless power transmitter is not in the second charging power limitation state, the wireless power transmitter can perform charging with the second guarantee power of S4540 (S2806).

29 is a diagram for explaining a packet format according to an embodiment of the second wireless power transmission procedure.

29, a packet format 2900 used for information exchange between the wireless power transmitting terminal 10 and the wireless power receiving terminal 20 according to the second wireless power transmission procedure includes a synchronization acquisition for demodulating the packet, A preamble field 2910 for identifying an accurate start bit of a packet, a header field 2920 for identifying a type of a message included in the packet, a contents (or payload) of the packet, A field for transmitting a message 2930, and a check sum field 2940 for checking whether an error has occurred in the packet.

The packet receiving end may identify the size of the message 2930 included in the packet based on the header 2920 value.

In addition, the header 2920 may be defined for each step of the wireless power transmission procedure, and some values of the header 920 may be defined at different levels. For example, referring to FIGS. 10 and 24, a 24-bit received power packet transmitted by a wireless power transmission apparatus and a power transmitter capability packet transmitted by a wireless power transmission apparatus correspond to a packet It should be noted that the header value may be equal to 0x31.

The message 2930 includes data to be transmitted at the transmitting end of the packet. For example, the data contained in the message 2930 field may be, but is not limited to, a report, a request, or a response to the other party.

The packet 2900 according to another embodiment may further include at least one of transmitting end identification information for identifying a transmitting end that transmitted the packet and receiving end identifying information for identifying a receiving end to receive the packet. Here, the transmitter identification information and the receiver identification information may include IP address information, MAC address information, product identification information, and the like. However, the present invention is not limited thereto.

The packet 2900 according to another embodiment may further include predetermined group identification information for identifying a corresponding receiving group when the packet is to be received by a plurality of apparatuses.

The packet transmitted from the wireless power receiver to the wireless power transmitter according to the second wireless power transmission procedure includes a signal strength packet for transmitting the strength information of the detected ping signal, a power for requesting the transmitter to stop the power transmission A power control hold-off packet for transmitting time information for waiting until the actual power is adjusted after receiving a control error packet for controlling an end power transfer packet and transmission power, An Identification Packet and an Extended Identification Packet for transmitting the receiver identification information, a Power Transmitter Capability Packet for checking the transmittable power of the transmitter, General request packet to send general request message, General request packet to send special request message A specific request packet, a FOD status packet for transmitting a reference quality factor value for FO detection, a control error packet for controlling transmission power of the transmitter, a renegotiation for starting renegotiation A 24-bit received power packet for transmitting the received power intensity information, an 8-bit received power packet for transmitting the received power information, And may include a Charge Status packet.

The packets transmitted from the wireless power receiver to the wireless power transmitter may be transmitted using in-band communication using the same frequency band as that used for wireless power transmission.

30 is a diagram for explaining a signal strength packet according to an embodiment of the second wireless power transmission procedure.

Referring to FIG. 30, the message format of the signal strength packet 3001 according to an embodiment may be composed of a signal strength value having a size of 1 byte. The signal strength value may indicate the degree of coupling between the transmitting coil and the receiving coil and may be calculated based on the rectifier output voltage in the digital ping section, the open circuit voltage measured in the output blocking switch, Lt; / RTI > The signal strength value may range from a minimum of 0 to a maximum of 255 and may have a value of 255 if the actual measured value for a particular variable is equal to the maximum value of that variable (Umax).

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

31 is a diagram for explaining a power transmission end packet according to an embodiment of the second wireless power transmission procedure;

Referring to FIG. 31, the message format of the power transmission termination packet 3101 according to one embodiment may be configured with a power transmission termination code having a size of 1 byte.

The reasons why the wireless power receiving apparatus requests the wireless power transmitter to terminate the power transmission include a charge complete, an internal fault, an over temperature, an over voltage, an over current, But is not limited to, battery failure, reconfiguration and no response, noise current, and the like. It should be noted that the power transmission interruption code may be additionally defined corresponding to each new power transmission termination reason.

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

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

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

Reconfiguration can be used when renegotiation is required for power transmission conditions.

No response can be used if the transmitter's response to the control error packet - meaning increasing or decreasing the strength of the power - is judged to be unhealthy.

The noise current, which is different from the overcurrent, can be used when the noise current value measured at the receiver exceeds the defined threshold value due to switching noise in the inverter.

32 is a diagram for explaining a power control hold packet according to an embodiment of the second wireless power transmission procedure;

Referring to FIG. 32, the message format of the power control hold packet 1301 may include a power control hole-off time (T_delay). The power control hold packet 1301 may be transmitted during the identification and configuration phase. For example, up to seven power control hold packets 1301 may be transmitted. The power control hold time (T_delay) may have a value between a predefined power control hold minimum time (T_min: 5 ms) and a power control hold maximum time (T_max: 205 ms). The wireless power transmission device can perform power control using the power control retention time of the last received power control retention packet 3201 in the identification and configuration step. In addition, if the power control hold packet 3201 is not received in the identification and configuration step, the wireless power transmission apparatus can use the T_min value as the T_delay value.

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

33 is a diagram for explaining a configuration packet according to an embodiment of the second wireless power transmission procedure.

33, the message format of the configuration packet 3301 may have a length of 5 bytes and may include a power class field, a maximum power field, a power control (Prop) field, a zero A Count field, a Window Size field, a Window Offset field, a Neg field, a Polarity field, a Depth field, and the like .

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

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

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

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

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

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

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

The negotiation field, if a value of 1, sends an ACK response to the wireless power receiving device indicating that it is entering negotiation phase.

The polarity field can determine the polarity of the FSK. For example, a polarity field value of 1 tells the wireless power sender to use the default FSK polarity. A polarity field value of 0 indicates that the wireless power transmitter is using the inverse FSK polarity.

The depth field allows you to select the FSK modulation depth.

34 is a diagram for explaining an identification packet and an extension identification packet according to an embodiment of the second wireless power transmission procedure;

34, the message format of the identification packet 3401 includes a Version Information field, a Manufacturer Information field, an Extension Indicator field, and a Basic Device Identification Information field As shown in FIG.

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

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

The extension indicator field may be an indicator for identifying whether an extended identification packet 3402 including extended device identification information exists. For example, if the value of the extension indicator is 0, it means that there is no extension identification packet, and if the extension indicator value is 1, it means that the extension identification packet exists after the identification packet.

Referring to reference numerals 1501 to 1502, if the extension indicator value is 0, the device identifier for the corresponding wireless power receiver may be a combination of manufacturer information and basic device identification information. On the other hand, if the extension indicator value is 1, the device identifier for the wireless power receiver may be a combination of manufacturer information, basic device identification information, and extended device identification information.

FIG. 35 is a diagram for explaining a general request packet according to an embodiment of the second wireless power transmission procedure. FIG.

Referring to FIG. 35, the message format of the general request packet 3501 may include a Request field.

The request field may be used by the wireless power receiver to request certain information from the wireless power transmitter. For example, the request field may be set to 0x31 to request the power transmitter capability packet of the wireless power transmitter.

General request packet 3501 may be transmitted if a change of power transfer contract or power transfer contract is required.

In one example, the wireless power receiver may send a general request packet 3501 for a power transfer contract in the negotiation step.

As another example, the wireless power transmission apparatus may determine that a change of the power transmission contract is required in the power transmission step. In this case, the wireless power transmission apparatus can transmit the NAK packet in response to the reception of the received power packet. Thereafter, the wireless power receiving apparatus receiving the NAK packet can transmit the general request packet 3501 to the wireless power transmitting apparatus to perform the renegotiation step.

FIG. 36 is a diagram for explaining a special request packet according to an embodiment of the second wireless power transmission procedure. FIG.

Referring to FIG. 36, the message format of the special request packet 3601 may include a request field and a request parameter field.

In the request field, information regarding a parameter to be changed may be recorded.

The requested parameter field may be written with the changed value of the parameter specified by the request field.

For example, referring to reference numeral 3602, if a change in the count, which is a parameter of the power transfer contract, is required in the negotiation step, the wireless power receiver records 0x00 in the request field and a change count, Can be recorded and transmitted. In addition, to terminate the negotiation phase or renegotiation phase for the power transfer contract, the wireless power receiver may transmit 0x00 in the request field. That is, if the request field is 0x00, the negotiation phase or the renegotiation phase can be terminated as well as changing the count of the power transmission contract. In addition, when a change in the guaranteed power value, which is a parameter of the power transmission contract, is requested, the wireless power receiver can write 0x01 in the request field and write and transmit the guaranteed power value in the request parameter field. In addition, when it is desired to use a 24-bit received power packet in the power transmitting step, the wireless power receiver can write 0x02 in the request field and write the header of the 24-bit received power packet in the request parameter field.

37 is a diagram for explaining an FOD status packet according to an embodiment of the second wireless power transmission procedure.

Referring to FIG. 37, the message format of the FOD status packet 3701 may include a Mode field and a Reference Quality Factor Value field.

The mode field may be used to indicate the operating mode of the wireless power receiver to which the reference quality factor value is applied. For example, if the mode field is '00', the wireless power receiver may be in a power off state.

The reference quality factor value field may record the reference quality factor value used to determine the threshold for FO detection in the negotiation step.

38 is a diagram for explaining a control error packet according to an embodiment of the second wireless power transmission procedure.

Referring to FIG. 38, the message format of the control error packet 3801 may include a 1-byte Control Error Value field.

The control error value field may contain a control error value. The control error value may be an integer value ranging from -128 to +127. If the control error value is negative, the transmission power of the radio power transmission apparatus decreases, and if it is positive, the transmission power of the radio power transmission apparatus can be increased. If the control error value is 0, the output power of the wireless power transmitting apparatus may be increased or decreased. In particular, a control error packet (CEP) with a control error value of zero may be referred to as a stable control error packet.

In addition, the control error packet 3801 may be transmitted by the wireless power receiving apparatus during the power transmitting step.

39 is a diagram for explaining a renegotiated packet according to an embodiment of the second wireless power transmission procedure.

Referring to FIG. 39, the message format of the renegotiated packet 3901 may include a reserved field preset to a certain value. In one example, the reserved field may be set to zero.

The renegotiated packet 3901 may be transmitted if a change of the power transmission contract is required in the power transmission step.

As an example, the wireless power receiving apparatus may determine that a change of the power transmission contract is necessary in the power transmission step. In this case, the wireless power receiving device may transmit the renegotiated packet 3901 to the wireless power transmitting device to perform the renegotiation step.

As another example, the wireless power transmission apparatus may determine that a change of the power transmission contract is required in the power transmission step. In this case, the wireless power transmission apparatus can transmit the NAK packet in response to the reception of the received power packet. Thereafter, the wireless power receiving device receiving the NAK packet may send the renegotiated packet 3901 to the wireless power transmitting device to perform the renegotiation step.

40 is a diagram for explaining a message format of an 8-bit received power packet according to an embodiment of the second wireless power transmission procedure.

Referring to FIG. 40, the message format of the 8-bit RX packet 4001 may include a Received Power Value field of 1 byte.

The received power value field may record the received power value. The received power value may correspond to the average rectifier received power value calculated during a predetermined period. The actual received power amount (Preceived) can be calculated based on the maximum power and the power class included in the configuration packet. As an example, the actual amount of power received can be calculated by (received power value / 128) * (maximum power / 2) * (10 ^ power rating).

41 is a diagram for explaining a 24-bit received power packet according to an embodiment of the second wireless power transmission procedure.

Referring to FIG. 41, the message format of the 24-bit received power packet 4101 may include a 1-byte Mode field and a 2-byte Received Power Value field.

The mode field may be used to provide additional information regarding the received power value. The mode field may also be used to request the response of the wireless power transmission device to the reception of the 24 bit receive power packet 4101. For example, if the mode field is '000', '001', or '010', the wireless power receiving device may request the wireless power transmitting device to receive a response to the reception of the 24 bit receiving power packet 4101. In this case, the wireless power transmission apparatus can transmit a NAK packet or an ACK packet to the wireless power receiving apparatus. If the mode field is '100', the wireless power receiving device may not request a response to the reception of the 24 bit received power packet 4101 to the wireless power transmitting device. In this case, the wireless power transmission apparatus may not transmit the NAK packet or the ACK packet to the wireless power reception apparatus.

The received power value field may record the received power value. The received power value may correspond to the average rectifier received power value calculated during a predetermined period. The actual received power amount (Preceived) can be calculated by the wireless power transmission device based on the maximum power included in the power transmission contract. As an example, the actual received power amount (Preceived) can be calculated by (received power value / 32768) * (maximum power).

FIG. 42 is a diagram for explaining a message format of a charge state packet according to an embodiment of the second wireless power transmission procedure. FIG.

Referring to FIG. 42, the message format of the charge state packet 4201 may include a 1-byte Charge Status Value field.

The charge state value field may record the charge state value. The charge state value may indicate the battery charge amount of the wireless power receiving device. For example, the charge state value 0 means a completely discharged state, the charge state value 50 may mean a 50% charge state, and the charge state value 100 may mean a full charge state. If the wireless power receiving device does not include a rechargeable battery or can not provide charge state information, the charge state value may be set to OxFF.

Figure 43 is a diagram for describing packets and power transmitter capability packets transmitted from a wireless power transmitter to a wireless power receiver in accordance with an embodiment of a second wireless power transmission procedure.

Referring to FIG. 43, a packet 4301 transmitted from a wireless power transmitter to a wireless power receiver may include a power transmitter capability packet 4302 for confirming transmittable power of the transmitter.

The packet 4301 transmitted from the wireless power transmitter to the wireless power receiver may be transmitted using in-band communication using the same frequency band as that used for wireless power transmission.

The message format of the power transmitter capability packet 4302 includes a Power Class field, a Guaranteed Power Value field, a Potential Power Value field, a WPID field, and a Not Res sens field Can be configured.

The power rating may be set to '00'.

The guaranteed power value may be the amount of power delivered by the wireless power transmitter depending on the condition. That is, the guaranteed power value may be a variation value that may vary depending on the state of the wireless power transmitter. In one example, when a plurality of transmitters share a single power supply, the energy provided by a single power supply is limited, so the guaranteed power value may vary depending on the number of wireless power receivers that the wireless power transmitter is providing power at the same time have. As another example, if the wireless power transmitter is in the first charge power limited state, the guaranteed power value may be set to a predetermined value.

The potential power value may be the amount of power delivered by the wireless power transmitter. That is, the potential power value may be a unique value determined according to the wireless power transmitter design, regardless of the state of the wireless power transmitter. In one example, when multiple transmitters share a single power supply, the potential power value may not vary depending on the number of wireless power receivers that the wireless power transmitter is simultaneously providing power to. As another example, if the wireless power transmitter is in the first charging power limited state, the potential power value may not change.

The power transmitter capability packet 4302 may be transmitted if a change of power transfer contract or power transfer contract is required.

In one example, the wireless power transmission device may send a power transmitter capability packet 4302 to the wireless power receiving device upon receipt of a generic request packet requesting a power transmitter capability packet 4302.

In another example, the wireless power transmission device may transmit the power transmitter capability packet 4302 to the wireless power reception device upon receipt of the renegotiated packet. More specifically, the wireless power transmission device may enter the renegotiation phase with the renegotiated packet reception and at the same time transmit the power transmitter capability packet 4302 to the wireless power reception device. More specifically, the wireless power transmission device may wish to proceed with the renegotiation phase by requiring a change in the power transfer contract depending on the power state of the wireless power transmission device. In this case, the wireless power transmission apparatus can transmit the power transmitter capability packet 4302 to the wireless power reception apparatus even if it does not receive the general request packet requesting the power transmitter capability packet 4302 upon receiving the resynchronization packet.

44 is a diagram for explaining a wireless charging method on a wireless charging system according to another embodiment.

44 illustrates a wireless charging method when performing a negotiation step of performing a power transfer contract to perform a wireless charging with a first guaranteed power on a wireless charging system and a wireless charging method until the renegotiation step or when a renegotiation step is not required Fig.

Referring to FIG. 44, the wireless power transmitter 4410 may transmit an analog ping to the wireless power receiver 4420 in a selection step (S4401).

The wireless power transmitter 4410 may transition from the selection stage to the ping stage when an object is sensed. The wireless power transmitter 4410 may activate the wireless power receiver 4420 and transmit a digital ping to identify if the receiver is a wireless power receiver 4420 compliant with the WPC standard (S4402). The wireless power receiver 4420 may transmit a signal strength packet in response to the digital ping (S4403).

Once the ping phase is complete, in the identification and configuration phase, the wireless power receiver 4420 may send an identification packet to inform the identification information and a configuration packet to inform the configuration information (S4404 to S4405). The wireless power transmitter 4410 and the wireless power receiver 4420 may transition to the negotiation phase if the negotiation field value of the configuration packet indicates a value to instruct to perform the negotiation step.

In the negotiation phase, the wireless power receiver 4420 may transmit the FOD status packet for FO detection (S4406). In addition, the wireless power receiver 4420 may send a generic request packet requesting a power transmitter capability packet for a power transmission contract (S4407). The wireless power transmitter 4420 may transmit the power transmitter capability packet in response to the general request packet (S4408). In this case, the guaranteed power of the power transmitter capability packet may be the first guaranteed power value. The first guaranteed power value may be a value close to a potential power value that is not subjected to a power limitation based on the number of wireless power transmitters or the number of wireless power receivers based on the power supplied from the power supply of the wireless power transmitter. For example, the first guaranteed power value may be the maximum transmission power value that the power transmitter can send out. The wireless power receiver 4420 may transmit a special request packet to suggest a guaranteed power value of the power transmission contract based on the first guaranteed power value of the power transmitter capability packet (S4407). Note that the guaranteed power of the power transmitter capability packet and the guaranteed power of the power transfer contract can be distinguished. For example, the wireless power receiver 4420 may suggest a guaranteed power value of the power transfer contract to a value equal to or less than the first guaranteed power value of the power transmitter capability packet. For convenience of description, the wireless power receiver 4420 suggests a value equal to the first guaranteed power value of the power transmitter capability packet as the guaranteed power value of the power transmission contract. The wireless power transmitter 4410 may send an ACK packet in response to a special request packet to suggest a guaranteed power value of the power transfer contract (S4410). That is, the wireless power transmitter 4410 accepts the guaranteed power value of the power transmission contract proposed by the wireless power receiver. That is, the power transfer contract can be completed with the first guaranteed power value. The wireless power receiver 4420 may then send a special request packet to terminate the negotiation phase upon completion of the power transfer contract (S4411). The wireless power transmitter 4410 may send an ACK packet in response to a special request packet to terminate the negotiation step (S4412). That is, the wireless power transmitter 4410 may send an ACK packet with an acceptance to the end of the negotiation phase.

In the calibration phase, the wireless power receiver 4420 may send a received power packet to the wireless power transmitter 4410 to predict power loss (S4413). In this case, the received power packet may be an 8-bit received power packet or a 24-bit received power packet. For example, if the received power packet is a 24 bit received power packet, the wireless power transmitter 4410 may transmit an ACK packet in response to the received power packet (not shown).

When the correction step is completed, the power transmission step can be performed with the first guaranteed power. The wireless power receiver 4420 may send one or more control error packets to control the transmit power of the wireless power transmitter 4410 (S4414). The wireless power receiver 4420 may periodically or optionally transmit the received power packet (S4416). In this case, the received power packet may be a 24-bit received power packet. The wireless power transmitter 4410 may send an ACK packet in response to the received power packet (S4416).

45 is a diagram for explaining a wireless charging method in a wireless power transmitter according to another embodiment.

Referring to Fig. 45, in the power transmission step, the wireless power transmitter can perform charging with the first guaranteed power (S4501). In this case, the first guaranteed power is a guaranteed power value of the power transmission contract. The guaranteed power may be a power intensity value determined by the wireless power transmitter and the wireless power receiver to transmit upon wireless charging in the power transfer phase by a power transfer agreement. More specifically, the guarantee power may include a first guarantee power having a relatively large guaranteed power value and a second guaranteed power having a relatively low guaranteed power value.

It can be determined whether the state is the first charging power limitation state (S4520). The first charging power limiting state may be a state in which the wireless power transmitter is constrained to perform charging at a specific charging power level. More specifically, the first charging power limiting state may be a state in which the transmission power of the wireless power transmitter should be reduced to a predetermined intensity. The wireless power transmitter may also be in a first charging power limited state due to one or more predetermined events. As an example, the predetermined event may be that the power loss of the wireless charge due to misplacement of the transmitter of the wireless power transmitter and the receiver of the wireless power receiver occurs above the first threshold power. In this case, when the wireless power transmitter determines that the first charging power limitation state is established and reduces the transmission power intensity, the wireless charging area increases. Accordingly, the wireless power transmitter can reduce the power loss of the wireless charging and proceed with wireless charging normally. The determination of the first charging power limitation state using the power loss follows the description of Fig. 17 described above. In another example, the predetermined event may be that the power loss of the wireless charge due to foreign matter (FO) between the wireless power transmitter and the wireless power receiver occurs above the first threshold power. In this case, the wireless power transmitter may determine that the power loss of the wireless charging is still high by determining the first charging power limit state and decreasing the output power intensity. Therefore, the wireless power transmitter can accurately determine that there is foreign matter (FO). The determination of the first charging power limitation state using the power loss follows the description of Fig. 17 described above. In another example, the predetermined event may occur in the driver of the wireless power transmitter with an overcurrent greater than or equal to the first threshold current. In this case, the wireless power transmitter can determine the first charging power limitation state and reduce the transmission power intensity, thereby preventing the overcurrent. The determination of the first charging power limitation state using the driving current follows the description of Fig. 18 described above. In another example, the predetermined event may occur in the driver of the wireless power transmitter with an overvoltage above the first threshold voltage. In this case, the wireless power transmitter can determine the first charging power limitation state and reduce the transmission power intensity to prevent the overvoltage. The determination of the first charging power limitation state using the driving voltage follows the description of FIG. 19 described above. In another example, a given event may occur at a wireless power transmitter with a high temperature phenomenon above a first threshold temperature. In this case, the wireless power transmitter may determine the first charging power limitation state and decrease the transmission power intensity to improve the heat generation phenomenon. The determination of the first charging power limitation state using the internal temperature follows the description of FIG. 20 described above. More specifically, the first charging power limiting state may be a state in which the transmission power of the wireless power transmitter is reduced to an intensity of 1 W or more and 6 W or less. More specifically, the first charging power limitation state may be a state for transmitting the transmission power of the wireless power transmitter with an intensity of 5W.

If it is determined that the first charging power limitation state is satisfied, the wireless power transmitter may perform the power transmission contract change to change from the first guarantee power to the second guarantee power (S4530). In a wireless power transmitter according to another embodiment, the intensity of the first guaranteed power is greater than the intensity of the second guaranteed power in the power transfer contract. For example, the first guaranteed power may be 15W and the second guaranteed power may be 5W. That is, the wireless power transmitter may determine the first charging power state and perform the power transmission contract change to reduce the transmission power. If it is determined that it is not the first charging power limit state, the wireless power transmitter can perform charging with the first guaranteed power of S4510.

After the power transfer contract change, the wireless power transmitter may perform charging with the second guaranteed power (S4540). For example, when charging is performed in the first charging mode, the wireless power transmitter can transmit the transmission power with an intensity of 5W.

It is possible to determine whether or not the battery is in the second charging power limitation state (S4550). The second charging power limiting state may be a state in which the wireless power transmitter must stop transmitting power. More specifically, the second charging power limiting state may be a state in which the wireless power transmitter determines that the power transmission should be stopped during wireless charging in the first charging power limiting state. That is, since the wireless power transmitter lowers the strength of the transmitted power because it is in the first charging power limiting state, it determines whether to stop the power transmission by determining the second charging power limiting state. For example, power loss due to wireless charging due to miss alignment between the transmitter of the wireless power transmitter and the receiver of the wireless power receiver may occur, and the wireless power may be reduced by lowering the transmission power during the first charging power limiting state. In this case, the wireless power transmitter can determine the second charging power limitation state if the power loss of the wireless charging is equal to or greater than the second threshold power. The determination of the second charging power limitation state using the power loss follows the description of FIG. 25 described above. As another example, a power loss due to a foreign matter (FO) due to a foreign matter (FO) may occur between the wireless power transmitter and the wireless power receiver, so that the transmission power may be lowered during the first charging power limiting state to advance the wireless charging. In this case, the wireless power transmitter can determine the second charging power limitation state if the power loss of the wireless charging is equal to or greater than the second threshold power. The determination of the second charging power limitation state using the power loss follows the description of FIG. 25 described above. As another example, an overcurrent may be generated in the driving unit of the wireless power transmitter, and the wireless power may be reduced by lowering the transmission power during the first charging power limiting state. In this case, the wireless power transmitter can determine the second charging power limitation state if the driving current is equal to or greater than the second threshold current. The determination of the second charging power limitation state using the driving current is based on the above-described twenty-sixth explanation. As another example, an overvoltage may be generated in the driving unit of the wireless power transmitter, and the wireless power may be reduced by lowering the transmission power during the first charging power limitation state. In this case, the wireless power transmitter can determine the second charging power limitation state if the driving voltage is equal to or higher than the second threshold voltage. The determination of the second charging power limitation state using the driving voltage follows the description of FIG. 27 described above. As another example, a high-temperature phenomenon may occur in the wireless power transmitter, and the wireless power may be reduced by lowering the transmission power during the first charging power limitation state. In this case, the wireless power transmitter can determine the second charging power limitation state if the internal temperature is equal to or higher than the second threshold temperature.

If it is determined that the second charging power limitation state is established, the wireless power transmitter can stop the power transmission (S4560). More specifically, the wireless power transmitter may stop the power transmission if the wireless power receiver determines that it is in the second charging power limit state even though the wireless power receiver does not request the power transmission interruption. If it is determined that the state is not the second charging power limitation state, the wireless power transmitter can perform charging with the second guaranteed power of S4540.

Thus, another embodiment may allow the wireless power transmitter to control the charging power. Still further, another embodiment may control the charging power according to the state of the wireless power transmitter. Still further, another embodiment may enlarge the charging area during wireless charging. Still further, another embodiment can improve the heating of the wireless power transmitter. Still another embodiment can improve the overvoltage phenomenon of a wireless power transmitter. Still another embodiment can improve the overcurrent phenomenon of a wireless power transmitter.

46 is a diagram for explaining an embodiment of the power transmission contract modification of FIG. 45 on the wireless charging system.

Referring to FIG. 46, when the wireless power transmitter 4610 determines the first charging power limitation state during the charging operation with the first guarantee power of the power transmission contract, the power transmission may be stopped (S4601). Thereafter, the wireless power transmitter 4610 may proceed with the second wireless power transmission procedure in the order of the selection step, the ping step, the identification and configuration step, and the negotiation step.

In the negotiation phase, the wireless power receiver 4620 may send a generic request packet requesting a power transmitter capability packet for the power transmission contract (S4602). The wireless power transmitter 4620 may transmit the power transmitter capability packet in response to the general request packet (S4603). In this case, the guaranteed power of the power transmitter capability packet may be the second guaranteed power value. The second guaranteed power value may be a reduced power value at the potential power value due to the first charge power limited state. The wireless power receiver 4620 may transmit a special request packet to suggest a guaranteed power value of the power transfer contract based on the second guaranteed power value of the power transmitter capability packet (S4604). Note that the guaranteed power of the power transmitter capability packet and the guaranteed power of the power transfer contract can be distinguished. For example, the wireless power receiver 4620 may propose a guaranteed power value of the power transfer contract to a value equal to or less than the second guaranteed power value of the power transmitter capability packet. For convenience of description, the wireless power receiver 4620 proposes a value equal to the second guaranteed power value of the power transmitter capability packet as the guaranteed power value of the power transmission contract. The wireless power transmitter 4610 may send an ACK packet in response to a special request packet to propose a guaranteed power value of the power transfer contract (S4605). That is, the wireless power transmitter 4610 has accepted the guaranteed power value of the power transmission contract proposed by the wireless power receiver. That is, the power transmission contract can be completed with the second guaranteed power value. The wireless power receiver 4620 may then send a special request packet to terminate the negotiation phase upon completion of the power transfer contract (S4606). The wireless power transmitter 4610 may send an ACK packet in response to a special request packet to terminate the negotiation step (S4607). That is, the wireless power transmitter 4610 may send an ACK packet with an acceptance to the end of the negotiation phase.

In the calibration phase, the wireless power receiver 4620 may send a received power packet to the wireless power transmitter 4610 to predict power loss (S4608). In this case, the received power packet may be an 8-bit received power packet or a 24-bit received power packet. For example, if the received power packet is a 24 bit received power packet, the wireless power transmitter 4610 may transmit an ACK packet in response to the received power packet (not shown).

When the correction step is completed, the wireless power transmitter 4610 and the wireless power receiver 4620 can perform wireless charging with the second guaranteed power by transiting to the power transmission step. The wireless power receiver 4620 may transmit one or more control error packets to control the transmit power of the wireless power transmitter 4610 (S4609).

47 is a view for explaining an embodiment of a power transmission contract change of Fig. 45 in a wireless power transmitter; Fig.

Referring to FIG. 47, FIG. 47 illustrates step S4530 of performing the power transmission contract change of FIG. 45 according to an embodiment in more detail.

The change of the power transmission contract of S4530 can be performed when the wireless power transmitter determines that the wireless power transmitter is in the first charging power limitation state during wireless charging with the first guarantee power (S4701).

The wireless power transmitter may stop power transmission (S4702). That is, the wireless power transmitter may cause the wireless power transmitter to stop transmitting the charging power that is being wirelessly charged, even if the wireless power receiver does not request to stop transmitting power.

The wireless power transmitter may reconnect with the wireless power receiver (S4703). That is, the wireless power transmitter may reconnect with the wireless power receiver to proceed with wireless charging after aborting the power transmission. Reconnection can proceed in the order of the selection step, the ping step, the identification and configuration step, and the negotiation step according to the second wireless power transmission procedure.

After transition to the negotiation phase, the wireless power transmitter may receive from the wireless power receiver a general request packet requesting a power transmitter capability packet for the power transmission contract (S4705).

Upon receiving the general request packet requesting the power transmitter capability packet, the wireless power transmitter may transmit the power transmitter capability packet including the second guaranteed power value to the wireless power receiver (S4705). That is, although the wireless power transmitter can provide the potential power value as the guaranteed power of the power transmitter capability packet based on the power supplied from the power supply section 460, 2 guaranteed power value as the guaranteed power value of the transmitter capability packet.

The wireless power transmitter may receive from the wireless power receiver a special request packet to suggest a guaranteed power value of the power transfer contract based on the second guaranteed power value of the power transmitter capability packet (S4706).

The wireless power transmitter may transmit an ACK packet to the wireless power receiver in response to a special request packet to suggest a guaranteed power value of the power transfer contract (S4707).

The wireless power transmitter may receive a special request packet from the wireless power receiver to complete the power transfer contract and terminate the negotiation phase (S4708).

The wireless power transmitter may transmit an ACK packet for accepting the end of negotiation phase (S4709).

The power transmission contract change may be terminated by entering the step S4540 of FIG. 45 after the power transmission contract is completed with the second guaranteed power and the negotiation step is terminated (S4710).

48 is a diagram for explaining another embodiment of the power transfer contract modification of FIG. 45 on the wireless charging system.

48 is a flowchart for explaining a method of performing a power transfer contract change by performing a renegotiation step on a wireless charging system.

Referring to FIG. 48, in the power transmission step of performing wireless charging with the first guarantee power, the wireless power transmitter can determine the first charging power limitation state (S4801).

The wireless power receiver 4820 may periodically or optionally transmit the received power packet (S4802). In this case, the received power packet may be a 24-bit received power packet. The wireless power transmitter 4810 may transmit the NAK packet in response to the reception of the received power packet when it is determined that the first state of charge power is limited (S4803). That is, the wireless power transmitter 4810 may send a NAK packet in response to receipt of a received power packet for a change in the power transfer contract. The wireless power transmitter 4810 may then send an ACK packet that accepts the renegotiated packet and accepts a transition to the renegotiation phase (S4804 through S4805). The wireless power receiver 4820 may send a generic request packet requesting a power transmitter capability packet (S4806). The wireless power transmitter 4810 may transmit the power transmitter capability packet in response to the general request packet (S4807). In this case, the guaranteed power of the power transmitter capability packet may be the second guaranteed power value. The second guaranteed power value may be a reduced power value at the potential power value due to the first charge power limited state. The wireless power receiver 4620 may send a special request packet to suggest a guaranteed power value of the power transfer contract based on the second guaranteed power value of the power transmitter capability packet (S4808). Note that the guaranteed power of the power transmitter capability packet and the guaranteed power of the power transfer contract can be distinguished. For example, the wireless power receiver 4820 may propose a guaranteed power value of the power transfer contract to a value equal to or less than the second guaranteed power value of the power transmitter capability packet. For convenience of description, the wireless power receiver 4820 proposes a value equal to the second guaranteed power value of the power transmitter capability packet as the guaranteed power value of the power transmission contract. The wireless power transmitter 4810 may send an ACK packet in response to a special request packet to propose a guaranteed power value of the power transfer contract (S4609). That is, the wireless power transmitter 4810 has accepted the guaranteed power value of the power transmission contract proposed by the wireless power receiver. That is, the power transmission contract can be completed with the second guaranteed power value. The wireless power receiver 4820 may then send a special request packet to terminate the renegotiation phase upon completion of the power transfer contract (S4809). The wireless power transmitter 4810 may send an ACK packet in response to a special request packet to end the renegotiation phase (S4810). That is, the wireless power transmitter 4610 may send an ACK packet with an acceptance to the end of the negotiation phase.

The wireless power transmitter 4810 and the wireless power receiver 4820 may transition to a power transfer stage to perform wireless charging with a second guaranteed power. The wireless power receiver 4820 may send one or more control error packets to control the transmit power of the wireless power transmitter 4810 (S4812).

FIG. 49 is a diagram for explaining another embodiment of the power transmission contract modification of FIG. 45 in the wireless power transmitter; FIG.

Referring to FIG. 49, FIG. 49 illustrates step S4530 of performing the power transmission contract change of FIG. 45 according to another embodiment in more detail.

The change of the power transmission contract of S4530 can be performed when the wireless power transmitter determines that the wireless terminal is in the first charging power limitation state during wireless charging with the first guaranteed power (S4901).

In the power transmission step, the wireless power transmitter may receive the received power packet from the wireless power receiver (S4902). The received power packet may be a 24-bit received power packet.

The wireless power transmitter may transmit the NAK packet to the wireless power receiver in response to the received power packet (S4903).

The wireless power transmitter may receive the renegotiated packet from the wireless power receiver (S4903).

The wireless power transmitter may send an ACK packet to the wireless power receiver in response to the renegotiated packet (S4905).

After transition to the renegotiation phase, the wireless power transmitter may receive a general request packet from the wireless power receiver requesting a power transmitter capability packet (S4906).

Upon receiving the general request packet requesting the power transmitter capability packet, the wireless power transmitter may transmit the power transmitter capability packet including the second guaranteed power value to the wireless power receiver (S4907). That is, although the wireless power transmitter can provide the potential power value as the guaranteed power of the power transmitter capability packet based on the power supplied from the power supply section 460, 2 guaranteed power value as the guaranteed power value of the transmitter capability packet.

The wireless power transmitter may receive a special request packet from the wireless power receiver to suggest a guaranteed power value of the power transfer contract based on the second guaranteed power value of the power transmitter capability packet (S4908).

The wireless power transmitter may transmit an ACK packet to the wireless power receiver in response to a special request packet to propose a guaranteed power value of the power transfer contract (S4909).

The wireless power transmitter may receive a special request packet to terminate the wo negotiation step after the power transfer contract has been completed from the wireless power receiver (S4910).

The wireless power transmitter may transmit an ACK packet for accepting the renegotiation phase end acknowledgment (S4911).

The power transfer contract change may be terminated by entering the step S4540 of FIG. 45 after the power transfer contract is completed with the second guaranteed power and the renegotiation phase is terminated (S4912).

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 (20)

A wireless charging method in a wireless power transmitter for wirelessly transmitting power to a wireless power receiver,
Performing charging with a first guaranteed power;
Determining whether the first charging power limitation state is being performed during the charging operation with the first guarantee power;
A power transfer contract changing step of changing from the first guarantee power to the second guarantee power when the first charging power limitation state is established; And
Performing charging with a second guaranteed power; And
And determining whether the second charging power limitation state is being performed with the second guarantee power. The method according to claim 1,
And stopping the power transmission if the second charging power limitation state is established. The method according to claim 1,
Wherein the first charging power limitation state is a state in which the transmission power of the wireless power transmitter is reduced to a predetermined intensity. The method of claim 3,
Wherein the second guaranteed power is a power of the wireless power transmitter of at least 1 W and at most 6 W. The method according to claim 1,
The first guaranteed power is high power,
Wherein the second guaranteed power is low power. The method according to claim 1,
The method of claim 1,
Measuring transmission power;
Receiving a received power packet including a received power value;
Calculating a power loss value based on the measured transmission power and the received power value; And
And determining whether the calculated power loss value is equal to or greater than a first threshold power,
And determines the first charging power limitation state if the calculated power loss value is equal to or greater than the first threshold power. The method according to claim 6,
Wherein the measuring the transmission power comprises sensing a driving current or a driving voltage applied to a driving unit of the wireless power transmitter and calculating the transmission power using a sensed driving current or a driving voltage. The method according to claim 6,
Wherein the power loss value is a difference of the received power value at the measured transmission power. The method according to claim 6,
Wherein the first threshold power is 2000 mW or more and 4500 mW or less. The method according to claim 1,
The method of claim 1,
Measuring a driving current applied to a driving unit of the wireless power transmitter; And
Determining whether the measured drive current value is greater than or equal to a first threshold current,
And determines the first charging power limitation state if the measured driving current value is equal to or greater than the first threshold current. The method according to claim 1,
The method of claim 1,
Measuring a driving voltage applied to a driving unit of the wireless power transmitter; And
And determining whether the measured drive voltage value is equal to or greater than a first threshold voltage,
And determining the first charging power limitation state if the measured driving voltage value is equal to or greater than the first threshold voltage. The method according to claim 1,
The method of claim 1,
Measuring an internal temperature of the wireless power transmitter; And
Determining whether the measured internal temperature value is greater than or equal to a first threshold temperature,
And determines the first charging power limitation state if the measured internal temperature value is equal to or higher than the first threshold temperature. The method according to claim 1,
The power transmission contract changing step includes:
Power transmission interruption step;
Reconnecting to the wireless power receiver;
Receiving a generic request packet requesting a power transmitter capability packet for a post-transition power transfer contract to a negotiation phase; And
And transmitting a power transmitter capability packet including a second guaranteed power value in response to the general request packet. The method of claim 1, wherein
The power transmission contract changing step includes:
Receiving a received power packet from the wireless power receiver in a power transmission step;
Transmitting a NAK packet upon receiving the received power packet;
Receiving a renegotiated packet from the wireless power receiver;
Transmitting an ACK packet in response to the renegotiated packet;
Receiving a generic request packet requesting a power transmitter capability packet for a post-transition power transfer contract to a renegotiation phase; And
And transmitting a power transmitter capability packet including a second guaranteed power value in response to the general request packet. The method according to claim 6,
The step of determining whether or not the second charging power limit state is satisfied,
Measuring transmission power;
Receiving a received power packet including a received power value;
Calculating a power loss value based on the measured transmission power and the received power value; And
And determining whether the calculated power loss value is equal to or greater than a second threshold power,
And if the calculated power loss value is equal to or greater than a second threshold power, determines the second charging power limitation state. 16. The method of claim 15,
Wherein the second threshold power is less than the first threshold power. 17. The method of claim 16,
And the second threshold power is 200 mW or more and 1400 mW or less. 11. The method of claim 10,
The step of determining whether or not the second charging power limit state is satisfied,
Measuring a driving current applied to a driving unit of the wireless power transmitter; And
And determining whether the measured driving current value is equal to or greater than a second threshold current,
If the measured drive current value is equal to or greater than the second threshold current,
Wherein the second threshold current is less than the first threshold current. 12. The method of claim 11,
The step of determining whether or not the second charging power limit state is satisfied,
Measuring a driving voltage applied to a driving unit of the wireless power transmitter; And
And determining whether the measured drive voltage value is equal to or greater than a second threshold voltage,
When the measured driving voltage value is greater than or equal to the second threshold voltage,
Wherein the second threshold voltage is less than the first threshold voltage. 13. The method of claim 12,
The step of determining whether or not the second charging power limit state is satisfied,
Measuring an internal temperature of the wireless power transmitter; And
Determining whether the measured internal temperature value is equal to or greater than a second threshold temperature,
If the measured internal temperature value is equal to or higher than the second threshold temperature,
Wherein the second threshold temperature is less than the first threshold temperature.

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