KR102312096B1 - Wireless power transfer method, apparatus and system - Google Patents

Abstract

The present invention is connected to the power converter and a power converter formed of a coil and a capacitor to convert a current into a magnetic flux to transmit power to the wireless power receiver, the current flowing in the coil and the voltage of the capacitor at least one phase An inverter unit formed of at least two switches connected to the phase detection unit for detecting and the power conversion unit to generate an AC voltage for controlling a resonant frequency of power transmitted from the power conversion unit, and the power conversion unit, the phase detection unit and a control unit controlling the inverter unit together to adjust the output of the power transmitted from the power conversion unit, wherein the control unit forms the inverter unit based on at least one phase of current and voltage detected by the phase detection unit It is characterized in that at least one of the two switches is determined when the on time of the switch is turned on.

Description

Wireless power transmission method, wireless power transmission device and wireless charging system {WIRELESS POWER TRANSFER METHOD, APPARATUS AND SYSTEM}

The present invention relates to a wireless power receiving method, a wireless power receiving apparatus, and a wireless charging system in the field of wireless power transmission and reception.

Traditionally, instead of a method of supplying electrical energy to wireless power receivers by wire, a method of supplying electrical energy wirelessly without contact is recently used. The wireless power receiver for wirelessly receiving energy may be directly driven by the received wireless power, or may charge a battery using the received wireless power and be driven by the charged power.

In order to smoothly transmit wireless power between the wireless power transmitter for transmitting the wireless power and the wireless power receiver for receiving wireless power, standardization (ie, standardization) of a technology related to wireless power transmission is in progress.

As part of the standardization of technology related to wireless power transmission, the Wireless Power Consortium, which deals with magnetic induction-based wireless power transmission technology, announced on April 12, 2010, interoperability in wireless power transmission. ) for “System Description Wireless Power Transfer, Volume 1, Low Power, Part 1: Interface Definition, Version 1.00 Release Candidate 1 "The standard document has been published.

Meanwhile, the Power Matters Alliance, another technical standard consultative body, was established in March 2012 and published a standard document based on inductive coupling technology to develop a family of interface standards and provide inductive resonance power. did.

The wireless charging method using electromagnetic induction as described above is already frequently encountered in our lives. For example, a wireless charging method using electromagnetic induction has been commercialized and utilized in electric toothbrushes, wireless coffee pots, and the like.

Recently, in the field of kitchen appliances requiring medium power, there is a need to develop a power transmission method and an apparatus for wirelessly transmitting and receiving power. More specifically, when transmitting heavy electricity wirelessly, a stability problem may occur due to a change in inductance of the coil.

Accordingly, in the present invention, there is a need for a method capable of controlling power while maintaining the stability of the entire system even at medium power or higher wireless power.

An object of the present invention is to provide a method of controlling a switch for power control while maintaining stability of a wireless power system in a wireless power transmitter for wirelessly transmitting power.

The present invention relates to a wireless power receiving method, a wireless power receiving apparatus, and a wireless charging system in the field of wireless power transmission and reception, and a power conversion formed of a coil and a capacitor to convert current into magnetic flux to transmit power to the wireless power receiver It is connected to the power converter and the phase detector for detecting at least one phase of the current flowing in the coil and the voltage of the capacitor and connected to the power converter, the resonance frequency of the power transmitted from the power converter an inverter unit formed of at least two switches to generate an alternating voltage for controlling The control unit may determine an on time of at least one of the at least two switches forming the inverter unit based on at least one phase of the current and the voltage detected by the phase detection unit.

In an embodiment, the control unit detects a time period in which the at least one switch can be turned on based on any one phase of the current and the voltage detected by the phase detection unit.

In an embodiment, the time period during which the at least one switch can be turned on is determined based on a point in time when the phase of the current detected by the phase detector becomes zero.

In an embodiment, the inverter unit includes a first switch and a second switch connected in series with the first switch, and when the control unit is switched from an on state to an off state, the first switch It is characterized in that the second switch is turned on within a time interval from a time when the coil current is turned off to a time before the phase of the coil current detected by the phase detection unit becomes zero.

In one embodiment, the control unit is characterized in that the off-time of the at least two switches is determined by the amount of power transmitted to the wireless power receiver.

In an embodiment, the control unit determines an off time point at which at least one of the at least two switches is switched from an on state to an off state based on the wireless power signal received from the wireless power receiver. characterized.

In an embodiment, the wireless power signal received from the wireless power receiver includes information on the amount of power required by the receiver, and when the control unit determines that the amount of power included in the wireless power signal is the first amount of power, the first A time point is determined as an off time point, and when the amount of power included in the wireless power signal is a second amount of power greater than the first amount of power, a second time point later than the first time point so that the effective duty of the at least one switch increases It is characterized in that it is determined as an off time point.

In an embodiment, the wireless power signal received from the wireless power receiver is periodically received at a preset time interval while power is transmitted to the receiver by the power converter, and the controller periodically Based on the received wireless power signal, the at least one switch is characterized in that the off time is changed.

In one embodiment, the inverter unit includes a first switch and a second switch connected in series with each other, and a third switch and a fourth switch connected in parallel with the first switch and the second switch, and connected in series with each other, The control unit determines an on time of the second switch according to an off time of the first switch, and determines an on time of the fourth switch according to an off time of the third switch.

In an embodiment, the off time of the first switch and the third switch is characterized in that it is determined by the amount of power transmitted to the wireless power receiver.

A control method of a wireless power transmitter for wirelessly transmitting power, comprising: detecting a phase of a current flowing in a coil formed to transmit power to a receiver by converting current into magnetic flux; and wattage information from the wireless power receiver Receiving a wireless power signal and determining an ON time of at least two switches connected to the coil based on the phase of the detected current to adjust the output of the power, respectively, and any of the at least two switches In a state in which one of the switches is turned on, an OFF time point of the one of the switches is determined based on the wireless power signal received from the wireless power receiver.

In an embodiment, the on-time of the at least two switches is determined based on a time when the phases of the detected currents are switched.

In an embodiment, the at least two switches include a first switch and a second switch connected to each other in series, and the on-time of the second switch is detected from the off-time of the first switch, the off-time of the off-time. It is characterized in that it is determined within the time interval up to the point in time when the phase of the current becomes 0.

In an embodiment, when the at least two switches are turned off, when the amount of power is the first amount of power, the first time is determined as the off time, and when the amount of power is a second amount of power greater than the first amount of power, the It is characterized in that the second time point later than the first time point is determined as the off time point.

In the above, a method for controlling the amount of power of the wireless power transmitter has been described. According to the present invention, by determining the on/off timing of the plurality of switches constituting the inverter unit based on the phase and wattage information of the current or voltage of the power converter, it is possible to maintain soft switching and control the amount of wattage.

In addition, the present invention can ensure the stability of the entire system by maintaining soft switching.

1 is an exemplary diagram conceptually illustrating a wireless power transmitter and a wireless power receiver according to embodiments of the present invention.
2A and 2B are block diagrams exemplarily showing the configurations of a wireless power transmitter and a wireless power receiver employable in the embodiments disclosed herein.
3 illustrates a concept in which power is wirelessly transferred from a wireless power transmitter to a wireless power receiver according to an inductive coupling method.
4 is a block diagram exemplarily showing a part of the configuration of a magnetic induction type wireless power transmitter and a wireless power receiver employable in the embodiments disclosed in the present specification.
5 is a block diagram of a wireless power transmitter configured to have one or more transmitting coils for receiving power according to an inductive coupling method employable in embodiments disclosed herein.
6 illustrates a concept in which power is wirelessly transferred from a wireless power transmitter to a wireless power receiver according to a resonance coupling method.
7 is a block diagram exemplarily showing a part of the configuration of a resonance type wireless power transmitter and a wireless power receiver employable in the embodiments disclosed in the present specification.
8 is a block diagram of a wireless power transmitter configured to have one or more transmitting coils for receiving power according to a resonant coupling method employable in embodiments disclosed herein.
9 illustrates a concept of transmitting and receiving a packet between a wireless power transmitter and an electronic device through modulation and demodulation of a wireless power signal in wireless power transmission according to embodiments disclosed herein.
10 illustrates a configuration for transmitting and receiving a power control message in wireless power transmission according to embodiments disclosed herein.
11A, 11B, and 11C show the form of a signal in modulation and demodulation performed in wireless power transmission according to embodiments disclosed herein.
12A, 12B and 12C illustrate a packet including a power control message used in a wireless power transfer method according to embodiments disclosed herein.
13 illustrates operating states of a wireless power transmitter and a wireless power receiver according to embodiments disclosed herein.
14 to 18 show the structures of packets including a power control message between the wireless power transmitter 100 and the wireless power receiver.
19 is a conceptual diagram illustrating a method in which a wireless power transmitter transmits power to one or more wireless power receivers.
20 is a block diagram illustrating the configuration of a wireless power transmitter according to an embodiment of the present invention.
21 is a circuit diagram illustrating the block diagram of FIG. 20 in more detail. 22 and 23 are structural diagrams showing the structures of different phase sensing units.
24 is a circuit diagram showing the structure of a half-bridge inverter.
25A and 25B are timing diagrams illustrating a method of switching the circuit of FIG. 24 .
26 is a circuit diagram showing the structure of a full-bridge inverter.
27A, 27B and 28 are timing diagrams illustrating different methods of switching the circuit of FIG. 26 .

The technology disclosed herein is applied to wireless power transmission. However, the technology disclosed herein is not limited thereto, and may be applied to all power transmission systems and methods, wireless charging circuits and methods, and other methods and apparatuses using wirelessly transmitted power to which the technical idea of the technology can be applied. .

It should be noted that technical terms used herein are used only to describe specific embodiments, and are not intended to limit the present invention. In addition, the technical terms used in this specification should be interpreted in the meaning generally understood by those of ordinary skill in the art to which the present invention belongs, unless otherwise defined in this specification, and excessively inclusive. It should not be construed in the meaning of a human being or in an excessively reduced meaning. In addition, when the technical terms used in the present specification are incorrect technical terms that do not accurately express the spirit of the present invention, they should be understood by being replaced with technical terms that those skilled in the art can correctly understand. In addition, general terms used in the present invention should be interpreted as defined in advance or according to the context before and after, and should not be interpreted in an excessively reduced meaning.

Also, as used herein, the singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as "consisting of" or "comprising" should not be construed as necessarily including all of the various components or various steps described in the specification, some of which components or some steps are It should be construed that it may not include, or may further include additional components or steps.

In addition, the suffixes "module" and "part" for components used in this specification are given or mixed in consideration of only the ease of writing the specification, and do not have a meaning or role distinct from each other by themselves.

Also, terms including ordinal numbers such as first, second, etc. used herein may be used to describe various components, but the components should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, a first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the accompanying drawings, but the same or similar components are assigned the same reference numerals regardless of reference numerals, and redundant description thereof will be omitted.

In addition, in the description of the present invention, if it is determined that a detailed description of a related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, it should be noted that the accompanying drawings are only for easy understanding of the spirit of the present invention, and should not be construed as limiting the spirit of the present invention by the accompanying drawings.

Justice

Many-to-one communication method: one transmitter (Tx) communicates with multiple receivers (Rx)

One-way communication: A communication method in which the receiver only transmits the necessary messages towards the transmitter.

Two-way communication: A communication method in which the sender is the receiver and the receiver is the transmitter, i.e. messages can be sent from both sides.

Here, the transmitter and the receiver have the same meaning as the transmitter and the receiver, respectively, and hereafter, these terms may be used interchangeably.

Conceptual diagram of a wireless power transmitter and a wireless power receiver

1 is an exemplary diagram conceptually illustrating a wireless power transmitter and a wireless power receiver according to embodiments of the present invention.

As can be seen with reference to FIG. 1 , the wireless power transmitter 100 may be a power transmitter that wirelessly transmits power required by the wireless power receiver 200 .

Also, the wireless power transmitter 100 may be a wireless charging device that charges the battery of the wireless power receiver 200 by wirelessly transmitting power.

In addition, the wireless power transmitter 100 may be implemented as various types of devices that transmit power to the wireless power receiver 200 that requires power in a non-contact state.

The wireless power receiver 200 is a device capable of operating by wirelessly receiving power from the wireless power transmitter 100 . Also, the wireless power receiver 200 may charge a battery using the received wireless power.

On the other hand, the wireless power receiving device for wirelessly receiving power described in this specification includes all portable electronic devices, such as input/output devices such as keyboards, mice, and auxiliary output devices for images or voices, cell phones, cellular phones, and smart phones. It should be interpreted as encompassing a smart phone, a personal digital assistant (PDA), a portable multimedia player (PMP), a tablet, or a multimedia device.

The wireless power receiver 200 may be a mobile communication terminal (eg, a mobile phone, a cellular phone, a tablet) or a multimedia device, as will be described later.

Meanwhile, the wireless power transmitter 100 may wirelessly transmit power to the wireless power receiver 200 without mutual contact by using one or more wireless power transfer methods. That is, the wireless power transmitter 100 includes an inductive coupling method based on a magnetic induction phenomenon by the wireless power signal and a resonance coupling method based on an electromagnetic resonance phenomenon by a wireless power signal of a specific frequency. ) may be used to deliver power.

The wireless power transmission by the inductive coupling method is a technology for wirelessly transmitting power using a primary coil and a secondary coil, and by inducing a current to the other coil through a magnetic field that changes in one coil due to magnetic induction, power This means that it is transmitted

In the wireless power transmission by the resonance coupling method, resonance occurs in the wireless power receiver 200 by the wireless power signal transmitted from the wireless power transmitter 100, and the wireless power transmitter by the resonance phenomenon It means that power is transferred from 100 to the wireless power receiver 200 .

Hereinafter, embodiments of the wireless power transmitter 100 and the wireless power receiver 200 disclosed in the present specification will be described in detail. In adding reference numerals to the components of the drawings below, the same reference numerals are used for the same components, even if they are indicated on different drawings, as much as possible.

2A and 2B are block diagrams exemplarily showing the configurations of the wireless power transmitter 100 and the wireless power receiver 200 employable in the embodiments disclosed herein.

wireless power transmitter

Referring to FIG. 2A , the wireless power transmitter 100 is configured to include a power transmission unit 110 . The power transmitter 110 may include a power conversion unit 111 and a power transmission control unit 112 .

The power converter 111 converts the power supplied from the transmitting-side power supply unit 190 into a wireless power signal and transmits it to the wireless power receiver 200 . The wireless power signal transmitted by the power converter 111 is formed in the form of a magnetic field or an electromagnetic field having an oscillation characteristic. To this end, the power converter 111 may be configured to include a coil generating the wireless power signal.

The power converter 111 may include components for forming different types of wireless power signals according to each power transmission method. For example, the power converter 111 may be configured to include a primary coil that forms a changing magnetic field to induce a current in the secondary coil of the wireless power receiver 200 according to an inductive coupling method. have. In addition, the power converter 111 may be configured to include a coil (or antenna) that forms a magnetic field having a specific resonance frequency in order to generate a resonance phenomenon in the wireless power receiver 200 according to a resonance coupling method. have.

In addition, the power converter 111 may transmit power by using one or more of the above-described inductive coupling method and resonant coupling method.

Among the components included in the power converter 111, those following the inductive coupling method will be described with reference to FIGS. 4 and 5, and those following the resonant coupling method will be described later with reference to FIGS. 7 and 8.

Meanwhile, the power converter 111 may be configured to further include a circuit capable of adjusting characteristics such as a frequency used to form the wireless power signal, an applied voltage, and a current.

The power transmission control unit 112 controls each component included in the power transmission unit 110 . The power transmission control unit 112 may be implemented to be integrated with another control unit (not shown) that controls the wireless power supply device 100 .

Meanwhile, an area to which the wireless power signal can reach may be divided into two categories. First, the active area refers to an area through which a wireless power signal transmitting power to the wireless power receiver 200 passes. Next, the sensing area (semi-active area) refers to a region of interest in which the wireless power transmitter 100 can detect the presence of the wireless power receiver 200 . Here, the power transmission control unit 112 may detect whether the wireless power receiver 200 is placed or removed in the active area or the sensing area. Specifically, the power transmission control unit 112 uses the wireless power signal formed by the power conversion unit 111, or the wireless power receiver 200 is located in the active area or detection area by a separately provided sensor. It is possible to detect whether it has been placed or not. For example, the power transmission control unit 112 may be affected by the wireless power signal due to the wireless power receiver 200 existing in the sensing area to form the wireless power signal of the power conversion unit 111 . The presence of the wireless power receiver 200 may be detected by monitoring whether the characteristics of the power for use are changed. However, the active area and the sensing area may be different according to a wireless power transfer method such as an inductive coupling method and a resonant coupling method.

The power transmission control unit 112 may perform a process of identifying the wireless power receiver 200 or determine whether to start wireless power transmission according to a result of detecting the presence of the wireless power receiver 200 have.

In addition, the power transmission control unit 112 may determine one or more characteristics of the frequency, voltage, and current of the power conversion unit 111 for forming the wireless power signal. The determination of the characteristic may be made according to a condition on the side of the wireless power transmitter 100 or a condition on the side of the wireless power receiver 200 .

The power transmission control unit 112 may receive a power control message from the wireless power receiver 200 . The power transmission control unit 112 may determine one or more characteristics of the frequency, voltage, and current of the power conversion unit 111 based on the received power control message, and other control based on the power control message. action can be performed.

For example, the power transmission control unit 112 forms the wireless power signal according to a power control message including at least one of rectified power amount information, charging state information, and identification information of the wireless power receiver 200 . It is possible to determine one or more characteristics of frequency, current, and voltage used for the purpose.

In addition, as another control operation using the power control message, the wireless power transmitter 100 may perform a general control operation related to wireless power transfer based on the power control message. For example, the wireless power transmitter 100 receives information to be output aurally or visually related to the wireless power receiver 200 through the power control message, or receives information required for authentication between devices. may be

In order to receive the power control message as described above, the power transmission control unit 112 may use at least one of a method of receiving the wireless power signal and a method of receiving other user data.

In order to receive the power control message, the wireless power transmitter 100 may be configured to further include a Power Communications Modulation/Demodulation Unit 113 electrically connected to the power converter 111 . . The modulation/demodulation unit 113 may be used to receive the power control message by demodulating the wireless power signal modulated by the wireless power receiver 200 .

In addition, in some embodiments, the power transmission control unit 112 receives the user data including the power control message by a communication means (not shown) included in the wireless power transmitter 100 to receive a power control message may be obtained.

[In case of supporting in-band two-way communication]

In addition, in a wireless power transmission environment capable of bidirectional communication according to the embodiments disclosed herein, the power transmission control unit 112 may transmit data to the wireless power receiver 200 . The data transmitted by the power transmission control unit 112 may be a request for the wireless power receiver 200 to transmit a power control message.

wireless power receiver

Referring to FIG. 2B , the wireless power receiver 200 is configured to include a power supply unit 290 . The power supply unit 290 supplies power required for the operation of the wireless power receiver 200 . The power supply unit 290 may include a power reception unit 291 and a power reception control unit 292 .

The power receiver 291 receives power wirelessly transmitted from the wireless power transmitter 100 .

The power receiver 291 may include components necessary to receive the wireless power signal according to a wireless power transfer method. In addition, the power receiver 291 may receive power according to one or more wireless power transfer schemes, and in this case, the power receiver 291 may include components necessary for each scheme together.

First, the power receiver 291 may be configured to include a coil for receiving a wireless power signal transmitted in the form of a magnetic or electromagnetic field having a vibrating characteristic.

For example, as a component according to an inductive coupling method, the power receiver 291 may include a secondary coil in which a current is induced by a changing magnetic field. In addition, the power receiver 291 may include a coil and a resonance circuit in which a resonance phenomenon is generated by a magnetic field having a specific resonance frequency as a component according to a resonance coupling method.

However, when the power receiver 291 receives power according to one or more wireless power transfer methods, the power receiver 291 is implemented to receive using one coil, or is formed differently according to each power transfer method. It may be implemented to receive using a coil.

Among the components included in the power receiver 291 , those following the inductive coupling method will be described with reference to FIG. 4 , and those following the resonant coupling method will be described with reference to FIG. 7 .

Meanwhile, the power receiver 291 may further include a rectifier and a regulator for converting the wireless power signal into direct current. In addition, the power receiver 291 may further include a circuit for preventing overvoltage or overcurrent from occurring due to the received power signal.

The power reception control unit 292 controls each component included in the power supply unit 290 .

Specifically, the power reception control unit 292 may transmit a power control message to the wireless power transmitter 100 . The power control message may instruct the wireless power transmitter 100 to start or end the transmission of the wireless power signal. Also, the power control message may instruct the wireless power transmitter 100 to adjust the characteristics of the wireless power signal.

In order to transmit the changed power control message, the power reception control unit 292 may use at least one of a method of transmitting through the wireless power signal and a method of transmitting through other user data.

In order to transmit the power control message, the wireless power receiver 200 may be configured to further include a Power Communications Modulation/Demodulation Unit 293 electrically connected to the power receiver 291 . The modulation/demodulation unit 293 may be used to transmit the power control message through the wireless power signal, similarly to the case of the wireless power transmitter 100 described above. The modulation/demodulation unit 293 may be used as a means for adjusting the current and/or voltage flowing through the power conversion unit 111 of the wireless power transmitter 100 . Hereinafter, a method in which the respective modulators 113 and 293 of the wireless power transmitter 100 side and the wireless power receiver 200 side are used for transmitting and receiving a power control message through a wireless power signal will be described. do.

The wireless power signal formed by the power converter 111 is received by the power receiver 291 . In this case, the power reception control unit 292 controls the modulation/demodulation unit 293 of the wireless power receiver 200 to modulate the wireless power signal. For example, the power reception control unit 292 may perform a modulation process such that the amount of power received from the wireless power signal changes accordingly by changing the reactance of the modulation/demodulation unit 293 connected to the power reception unit 291. have. A change in the amount of power received from the wireless power signal results in a change in current and/or voltage of the power converter 111 that forms the wireless power signal. At this time, the modulation/demodulation unit 113 on the side of the wireless power transmitter 100 detects a change in current and/or voltage of the power converter 111 and performs a demodulation process.

That is, the power reception control unit 292 generates a packet including a power control message to be transmitted to the wireless power transmitter 100 and modulates the wireless power signal to include the packet, and the power The transmission control unit 112 may obtain the power control message included in the packet by decoding the packet based on a result of the demodulation process performed by the modulation/demodulation unit 113 .

In addition, in some embodiments, the power reception control unit 292 transmits the user data including the power control message by a communication means (not shown) included in the wireless power receiver 200 to transmit a power control message. may be transmitted to the wireless power transmitter 100 .

[In case of supporting in-band two-way communication]

In addition, in a wireless power transmission environment capable of bidirectional communication according to the embodiments disclosed herein, the power reception control unit 292 may receive data transmitted from the wireless power transmitter 100 . The data transmitted from the wireless power transmitter 100 may request transmission of a power control message.

In addition, the power supply unit 290 may be configured to further include a charging unit 298 and a battery 299 .

The wireless power receiver 200 receiving power for operation from the power supply unit 290 operates by the power transferred from the wireless power transmitter 100 or the battery using the transferred power. After charging 299 , the battery 299 may be operated by power charged in the battery 299 . In this case, the power reception control unit 292 may control the charging unit 298 to perform charging using the transmitted power.

Hereinafter, a wireless power transmitter and a wireless power receiver applicable to the embodiments disclosed in the present specification will be described. First, a method of transmitting power from the wireless power transmitter to the wireless power receiver according to an inductive coupling method is disclosed with reference to FIGS. 3 to 5 .

Inductive coupling method

3 illustrates a concept in which power is wirelessly transferred from a wireless power transmitter to a wireless power receiver according to an inductive coupling method.

When the power transmission of the wireless power transmitter 100 follows the inductive coupling method, when the intensity of the current flowing in the primary coil in the power transmission unit 110 is changed, the primary coil by the current is changed. The magnetic field passing through it changes. The changed magnetic field generates an induced electromotive force on the side of the secondary coil in the wireless power receiver 200 .

According to this method, the power converter 111 of the wireless power transmitter 100 is configured to include a transmission coil (Tx coil) 1111a operating as a primary coil in magnetic induction. In addition, the power receiver 291 of the wireless power receiver 200 is configured to include a receiving coil (Rx coil) 2911a operating as a secondary coil in magnetic induction.

First, the wireless power transmitter 100 and the wireless power receiver 200 so that the transmitting coil 1111a of the wireless power transmitter 100 and the receiving coil of the wireless power receiver 200 are close to each other place the Then, when the power transmission control unit 112 controls the current of the transmitting coil 1111a to change, the power receiving unit 291 uses the electromotive force induced in the receiving coil 2911a to control the wireless power receiving device ( 200) to supply power.

Efficiency of wireless power transfer by the inductive coupling method is less affected by frequency characteristics, but alignment between the wireless power transmitter 100 and the wireless power receiver 200 including each coil and distance.

Meanwhile, for wireless power transmission by inductive coupling, the wireless power transmitter 100 may be configured to include an interface surface (not shown) in the form of a flat surface. One or more wireless power receivers may be placed on an upper portion of the interface surface, and the transmitting coil 1111a may be mounted on a lower portion of the interface surface. In that case, the vertical spacing between the transmitting coil 1111a mounted on the lower portion of the interface surface and the receiving coil 2911a of the wireless power receiver 200 located on the upper portion of the interface surface is formed to be small. The distance between the coils is sufficiently small so that wireless power transfer by the inductive coupling method can be efficiently performed.

In addition, an arrangement indicating unit (not shown) indicating a position where the wireless power receiver 200 is to be placed may be formed on the interface surface. The arrangement indicator indicates the position of the wireless power receiver 200 in which the arrangement between the transmitting coil 1111a and the receiving coil 2911a mounted on the lower portion of the interface surface can be properly made. The arrangement indicator may be a simple mark or may be formed in the form of a protruding structure guiding the position of the wireless power receiver 200 . Alternatively, the arrangement indicator is formed in the form of a magnetic material such as a magnet mounted on the lower portion of the interface surface, and the coils are arranged in a suitable manner by mutual attraction with magnetic materials of different poles mounted inside the wireless power receiver 200 . can guide you to achieve it.

Meanwhile, the wireless power transmitter 100 may be formed to include one or more transmitting coils. The wireless power transmitter 100 may increase power transmission efficiency by selectively using some of the coils suitably arranged with the receiving coil 2911a of the wireless power receiver 200 among the one or more transmitting coils. The wireless power transmitter 100 including the one or more transmitting coils will be described below with reference to FIG. 5 .

Hereinafter, the configuration of the wireless power transmitter and the wireless power receiver of the inductive coupling method applicable to the embodiments disclosed in the present specification will be described in detail.

Inductive coupling type wireless power transmitter and wireless power receiver

4 is a block diagram exemplarily showing a part of the configuration of the magnetic induction type wireless power transmitter 100 and the wireless power receiver 200 employable in the embodiments disclosed herein. The configuration of the power transmitter 110 included in the wireless power transmitter 100 will be described with reference to FIG. 4A , and the power supply unit included in the wireless power receiver 200 with reference to FIG. 4B ( 290) will be described.

Referring to FIG. 4A , the power converter 111 of the wireless power transmitter 100 may be configured to include a transmission coil 1111a and an inverter 1112 .

The transmitting coil 1111a, as described above, forms a magnetic field corresponding to a wireless power signal according to a change in current. The transmission coil 1111a may be implemented in a planar spiral type or a cylindrical solenoid type.

The inverter 1112 transforms a DC input obtained from the power supply unit 190 into an AC waveform. The alternating current transformed by the inverter 1112 drives a resonant circuit including the transmitting coil 1111a and a capacitor (not shown), whereby a magnetic field is formed in the transmitting coil 1111a. .

In addition, the power converter 111 may be configured to further include a positioning unit 1114 .

The positioning unit 1114 may move or rotate the transmitting coil 1111a in order to increase the efficiency of wireless power transmission by the inductive coupling method. This is, as described above, the power transfer by the inductive coupling method is the alignment and distance between the wireless power transmitter 100 and the wireless power receiver 200 including primary and secondary coils ( distance) is affected. In particular, the location determiner 1114 may be used when the wireless power receiver 200 does not exist within an active area of the wireless power transmitter 100 .

Accordingly, the position determining unit 1114 determines that the distance between the centers of the transmitting coil 1111a of the wireless power transmitter 100 and the receiving coil 2911a of the wireless power receiver 200 is A driving unit (not shown) for moving the transmitting coil 1111a to be within a certain range or rotating the transmitting coil 1111a so that the centers of the transmitting coil 1111a and the receiving coil 2911a overlap can be configured to

To this end, the wireless power transmitter 100 may further include a location detection unit (not shown) including a sensor for detecting the location of the wireless power receiver 200 , and the power transmission controller Unit 112 may control the position determiner 1114 based on the position information of the wireless power receiver 200 received from the position detection sensor.

In addition, for this purpose, the power transmission control unit 112 receives control information on the arrangement or distance with the wireless power receiver 200 through the modulation/demodulation unit 113 , and control information on the received arrangement or distance. The positioning unit 1114 may be controlled based on .

If the power converter 111 is configured to include a plurality of transmitting coils, the position determining unit 1114 may determine which one of the plurality of transmitting coils will be used for power transmission. The configuration of the wireless power transmitter 100 including the plurality of transmission coils will be described later with reference to FIG. 5 .

Meanwhile, the power conversion unit 111 may be configured to further include a power sensing unit 1115 . The power sensing unit 1115 of the wireless power transmitter 100 monitors the current or voltage flowing through the transmitting coil 1111a. The power sensing unit 1115 is to check whether the wireless power transmitter 100 operates normally, detects a voltage or current of power supplied from the outside, and determines whether the detected voltage or current exceeds a threshold value. can be checked Although not shown, the power sensing unit 1115 compares a resistance for detecting a voltage or current of power supplied from the outside and a voltage value or current value of the detected power with a threshold value and outputs the comparison result. It may include a comparator. Based on the confirmation result of the power sensing unit 1115 , the power transmission control unit 112 may control a switching unit (not shown) to cut off the power applied to the transmitting coil 1111a.

Referring to FIG. 4B , the power supply 290 of the wireless power receiver 200 may be configured to include a receiving coil (Rx coil) 2911a and a rectifying circuit 2913 .

A current is induced in the receiving coil 2911a by a change in the magnetic field formed from the transmitting coil 1111a. An implementation form of the receiving coil 2911a may be in the form of a flat plate spiral or a cylindrical solenoid, as in the case of the transmitting coil 1111a.

In addition, series and parallel capacitors may be configured to be connected to the receiving coil 2911a to increase wireless power reception efficiency or to perform resonant detection.

The receiving coil 2911a may be in the form of a single coil or a plurality of coils.

The rectifier circuit 2913 performs full-wave rectification on the current in order to convert the alternating current to the direct current. The rectifier circuit 2913 may be implemented as, for example, a full bridge rectifier circuit including four diodes or a circuit using active components.

In addition, the rectifier circuit 2913 may further include a smoothing circuit (regulator) that converts the rectified current into a flatter and more stable direct current. In addition, the output power of the rectifier circuit 2913 is supplied to each component of the power supply unit 290 . In addition, the rectifier circuit 2913 converts the output DC power into an appropriate voltage to match the power required for each component of the power supply unit 290 (eg, a circuit such as the charging unit 298 ) to a DC-DC converter. (DC-DC converter) may be further included.

The modulation/demodulation unit 293 is connected to the power receiver 291, and may be composed of a resistive element having a change in resistance with respect to a direct current, and a capacitive element with a change in reactance with respect to an alternating current. can be The power reception control unit 292 may modulate the wireless power signal received by the power reception unit 291 by changing the resistance or reactance of the modulation/demodulation unit 293 .

Meanwhile, the power supply unit 290 may be configured to further include a power sensing unit 2914 . The power sensing unit 2914 of the wireless power receiver 200 monitors the voltage and/or current of the power rectified by the rectifying circuit 2913, and as a result of the monitoring, the voltage and/or the rectified power source When the current exceeds the threshold value, the power reception control unit 292 transmits a power control message to the wireless power transmitter 100 to transmit appropriate power.

A wireless power transmitter comprising one or more transmitting coils

5 is a block diagram of a wireless power transmitter configured to have one or more transmitting coils for receiving power according to an inductive coupling method employable in embodiments disclosed herein.

Referring to FIG. 5 , the power converter 111 of the wireless power transmitter 100 according to the embodiments disclosed herein may include one or more transmitting coils 1111a-1 to 1111a-n. The one or more transmitting coils 1111a-1 to 1111a-n may be an array of partly overlapping primary coils. An active area may be determined by some of the one or more transmitting coils.

The one or more transmitting coils 1111a-1 to 1111a-n may be mounted under the interface surface. In addition, the power converter 111 may further include a multiplexer 1113 for establishing and releasing a connection of some of the one or more transmitting coils 1111a-1 to 1111a-n. .

When the position of the wireless power receiver 200 placed on the interface surface is sensed, the power transmission control unit 112 considers the detected position of the wireless power receiver 200 to the one or more transmitting coils ( Among 1111a-1 to 1111a-n), the multiplexer 1113 may be controlled so that the receiving coil 2911a of the wireless power receiver 200 and coils that may be in an inductively coupled relationship may be connected.

To this end, the power transmission control unit 112 may acquire location information of the wireless power receiver 200 . For example, the power transmission control unit 112 may acquire the position of the wireless power receiver 200 on the interface surface by the position detection unit (not shown) provided in the wireless power transmitter 100 . can For another example, the power transmission control unit 112 may use each of the one or more transmitting coils 1111a-1 to 1111a-n to receive a power control message indicating the strength of a wireless power signal from an object on the interface surface or Obtaining the location information of the wireless power receiver 200 by receiving a power control message indicating the identification information of the object, and determining which coil of the one or more transmitting coils is close to the location of the one or more transmitting coils based on the received result You may.

On the other hand, the active area is a part of the interface surface, and when the wireless power transmitter 100 wirelessly transmits power to the wireless power receiver 200, it means a part through which a magnetic field of high efficiency can pass. can In this case, a single transmitting coil or a combination of one or more transmitting coils that form a magnetic field passing through the active region may be referred to as a primary cell. Accordingly, the power transmission control unit 112 determines an active area based on the sensed position of the wireless power receiver 200 and establishes a connection of a main cell corresponding to the active area to the wireless power receiver ( 200), the multiplexer 1113 may be controlled so that the receiving coil 2911a and the coils belonging to the main cell are in an inductively coupled relationship.

In addition, the power converter 111 may further include an impedance matching unit (not shown) for adjusting impedance to form a resonant circuit with the connected coils.

Hereinafter, a method in which a wireless power transmitter transmits power according to a resonance coupling method is disclosed with reference to FIGS. 6 to 8 .

Resonant coupling method

6 illustrates a concept in which power is wirelessly transferred from a wireless power transmitter to a wireless power receiver according to a resonance coupling method.

First, the resonance (resonance) (or resonance) will be briefly described as follows. Resonance refers to a phenomenon in which the vibration system receives an external force having the same frequency as its natural frequency periodically and the amplitude clearly increases. Resonance is a phenomenon that occurs in all vibrations such as mechanical vibration and electrical vibration. In general, when a force capable of vibrating a vibrating system is applied from the outside, if the natural frequency of the vibrating system and the frequency of the external force are the same, the vibration becomes severe and the amplitude increases.

In the same principle, when a plurality of vibrating bodies spaced apart within a certain distance vibrate at the same frequency, the plurality of vibrating bodies resonate with each other, and in this case, resistance between the plurality of vibrating bodies is reduced. In electrical circuits, inductors and capacitors can be used to create resonant circuits.

When the power transmission of the wireless power transmitter 100 follows the resonance coupling method, a magnetic field having a specific vibration frequency is formed by the AC power in the power transmission unit 110 . When a resonance phenomenon occurs in the wireless power receiver 200 by the formed magnetic field, power is generated by the resonance phenomenon in the wireless power receiver 200 .

The resonant frequency may be determined, for example, by the following Equation (1).

[Equation 1]

Here, the resonance frequency (f) is determined by the inductance (L) and the capacitance (C) in the circuit. In a circuit for forming a magnetic field using a coil, the inductance may be determined by the number of rotations of the coil, and the capacitance may be determined by an interval and an area between the coils. In order to determine the resonant frequency, a capacitive resonant circuit may be connected in addition to the coil.

Referring to FIG. 6 , when power is transmitted wirelessly according to a resonance coupling method, the power converter 111 of the wireless power transmitter 100 includes a transmission coil 1111b in which a magnetic field is formed, and It may be configured to include a resonance circuit (or resonance forming circuit, 1116) connected to the transmitting coil 1111b and determining a specific vibration frequency (hereinafter, a resonance circuit or a resonance forming circuit will be used interchangeably) have. The resonance circuit 1116 may be implemented using capacitive circuits (capacitors), and the specific vibration frequency is determined based on the inductance of the transmission coil 1111b and the capacitance of the resonance circuit 1116 .

The configuration of the circuit element of the resonance circuit 1116 may be made in various forms so that the power converter 111 can form a magnetic field, and is connected in parallel with the transmission coil 1111b as shown in FIG. 6 . not limited.

In addition, the power receiver 291 of the wireless power receiver 200 includes a resonance circuit 2912 and a receiving coil (Rx coil) configured to cause a resonance phenomenon by the magnetic field formed in the wireless power transmitter 100 . (2911b). That is, the resonant circuit 2912 may also be implemented using a capacitive circuit, and the resonant circuit 2912 is determined based on the inductance of the receiving coil 2911b and the capacitance of the resonant circuit 2912 It is configured such that the resonant frequency is equal to the resonant frequency of the formed magnetic field.

The configuration of the circuit element of the resonance circuit 2912 can be made in various forms so that the power receiver 291 can resonate by the magnetic field, and is connected in series with the receiver coil 2911b as shown in FIG. It is not limited to the form.

The specific vibration frequency in the wireless power transmitter 100 may be obtained using Equation 1 with LTx and CTx. Here, when the result of substituting LRX and CRX of the wireless power receiver 200 into Equation 1 is the same as the specific vibration frequency, resonance occurs in the wireless power receiver 200 .

According to the wireless power transmission method by resonance coupling, when the wireless power transmitter 100 and the wireless power receiver 200 each resonate at the same frequency, the electromagnetic wave is transmitted through a short-range electromagnetic field. There is no energy transfer between devices.

Therefore, while the efficiency of wireless power transfer by the resonance coupling method is greatly affected by frequency characteristics, the arrangement between the wireless power transmitter 100 and the wireless power receiver 200 including each coil and The effect of distance is relatively small compared to the inductive coupling method.

Hereinafter, the configuration of the wireless power transmitter and the wireless power receiver of the resonance coupling method applicable to the embodiments disclosed in the present specification will be described in detail.

Resonant coupling method wireless power transmitter

7 is a block diagram exemplarily showing a part of the configuration of the resonance type wireless power transmitter 100 and the wireless power receiver 200 employable in the embodiments disclosed in the present specification.

A configuration of the power transmitter 110 included in the wireless power transmitter 100 will be described with reference to FIG. 7A .

The power converter 111 of the wireless power transmitter 100 may be configured to include a transmission coil 1111b, an inverter 1112 and a resonance circuit 1116 . The inverter 1112 may be configured to be connected to the transmitting coil 1111b and the resonance circuit 1116 .

The transmitting coil 1111b may be mounted separately from the transmitting coil 1111a for transmitting power according to an inductive coupling method, but may also transmit power using an inductive coupling method and a resonant coupling method using one single coil.

The transmitting coil 1111b, as described above, forms a magnetic field for transmitting power. The transmission coil 1111b and the resonance circuit 1116 may vibrate when AC power is applied. At this time, the vibration frequency is based on the inductance of the transmission coil 1111b and the capacitance of the resonance circuit 1116. can be decided.

To this end, the inverter 1112 transforms the DC input obtained from the power supply unit 190 into an AC waveform, and the transformed AC current is applied to the transmitting coil 1111b and the resonance circuit 1116 .

In addition, the power converter 111 may be configured to further include a frequency adjuster 1117 for changing the resonant frequency value of the power converter 111 . Since the resonant frequency of the power converter 111 is determined based on the inductance and capacitance in the circuit constituting the power converter 111 by Equation 1, the power transmission controller 112 controls the inductance and/or The resonance frequency of the power converter 111 may be determined by controlling the frequency controller 1117 to change the capacitance.

The frequency adjusting unit 1117 includes, for example, a motor capable of changing the capacitance by adjusting the distance between capacitors included in the resonance circuit 1116, or the number of rotations of the transmitting coil 1111b ( It may include a motor capable of changing the inductance by adjusting the number of turns or diameter, or it may be configured to include active elements that determine the capacitance and/or inductance.

Meanwhile, the power conversion unit 111 may be configured to further include a power sensing unit 1115 . The operation of the power sensing unit 1115 is the same as described above.

A configuration of the power supply unit 290 included in the wireless power receiver 200 will be described with reference to FIG. 7B . The power supply unit 290, as described above, may be configured to include the receiving coil (Rx coil) 2911b and the resonance circuit (2912).

In addition, the power receiving unit 291 of the power supply unit 290 may be configured to further include a rectifying circuit 2913 for converting an alternating current generated by a resonance phenomenon into a direct current. The rectifier circuit 2913 may have the same configuration as described above.

In addition, the power receiving unit 291 may be configured to further include a power sensing unit 2914 for monitoring the voltage and/or current of the rectified power. The power sensing unit 2914 may have the same configuration as described above.

A wireless power transmitter comprising one or more transmitting coils

8 is a block diagram of a wireless power transmitter configured to have one or more transmitting coils for receiving power according to a resonant coupling method employable in embodiments disclosed herein.

Referring to FIG. 8 , the power converter 111 of the wireless power transmitter 100 according to the embodiments disclosed herein is connected to one or more transmitting coils 1111b-1 to 1111b-n and each of the transmitting coils. It may be configured to include resonant circuits 1116-1 to 1116-n. In addition, the power converter 111 may further include a multiplexer 1113 for establishing and releasing the connection of some of the one or more transmission coils 1111b-1 to 1111b-n. .

The one or more transmitting coils 1111b-1 to 1111b-n may be set to have the same resonant frequency, or some may be set to have different resonant frequencies. This is determined according to which inductance and/or capacitance the resonant circuits 1116-1 to 1116-n respectively connected to the one or more transmitting coils 1111b-1 to 1111b-n have.

To this end, the frequency adjusting unit 1117 may change the inductance and/or capacitance of the resonance circuits 1116-1 to 1116-n respectively connected to the one or more transmitting coils 1111b-1 to 1111b-n. It can be configured to

In - band communication

9 illustrates a concept of transmitting and receiving a packet between a wireless power transmitter and an electronic device through modulation and demodulation of a wireless power signal in wireless power transmission according to embodiments disclosed herein.

Referring to FIG. 9 , the power converter 111 included in the wireless power transmitter 100 forms a wireless power signal. The wireless power signal is formed through the transmission coil 1111 included in the power converter 111 .

The wireless power signal 10a formed by the power converter 111 arrives at the electronic device 200 and is received through the power receiver 291 included in the electronic device 200 . The formed wireless power signal is received through the receiving coil 2911 included in the power receiver 291 .

The power reception control unit 292 controls the modulation/demodulation unit 293 connected to the power reception unit 291 to modulate the wireless power signal while the electronic device 200 receives the wireless power signal. . When the received wireless power signal is modulated, the wireless power signal forms a closed-loop in a magnetic field or an electromagnetic field, so that the electronic device 200 operates the wireless When the wireless power signal is modulated while receiving the power signal, the wireless power transmitter 100 may detect the modulated wireless power signal 10b. The modulator 113 may demodulate the sensed wireless power signal and decode the packet from the demodulated wireless power signal.

Meanwhile, a modulation method used for communication between the wireless power transmitter 100 and the electronic device 200 may be amplitude modulation. As described above, in the amplitude modulation method, the modulation/demodulation unit 293 of the electronic device 200 changes the amplitude of the wireless power signal 10a formed by the power conversion unit 111 to change the wireless power transmitter. The modulation/demodulation unit 293 on the (100) side may be a backscatter modulation scheme for detecting the amplitude of the modulated wireless power signal 10b.

Modulation and demodulation of wireless power signals

Hereinafter, modulation and demodulation of packets transmitted/received between the wireless power transmitter 100 and the electronic device 200 will be described with reference to FIGS. 10 and 11A, 11B and 11C.

10 illustrates a configuration for transmitting and receiving a power control message in wireless power transmission according to embodiments disclosed herein. 11 illustrates a signal shape in modulation and demodulation performed in wireless power transmission according to embodiments disclosed herein.

Referring to FIG. 10 , the wireless power signal received through the power receiver 291 on the side of the electronic device 200 is an unmodulated wireless power signal 10a as shown in FIG. 11A . Resonant coupling is made between the electronic device 200 and the wireless power transmitter 100 according to the resonance frequency set by the resonance forming circuit 2912 in the power receiver 291, and the receiving coil 2911b Through the wireless power signal (10a) is received.

The power reception control unit 292 modulates the wireless power signal 10a received through the power reception unit 291 by changing the load impedance in the modulation/demodulation unit 293 . The modulation/demodulation unit 293 may be configured to include a passive element 2931 and an active element 2932 for modulating the wireless power signal 51 . The modulation/demodulation unit 293 modulates the wireless power signal 10a to include a packet to be transmitted to the wireless power transmitter 100 . In this case, the packet may be input to the active element 2932 in the modulation/demodulation unit 293 .

Thereafter, the power transmission control unit 112 of the wireless power transmitter 100 side demodulates the modulated wireless power signal 10b through an envelope detection process, and generates the detected signal 10c. It is decoded into digital data (54). The demodulation process detects that the current or voltage flowing through the power converter 111 is divided into two states, HI state and LO state, by the modulated wireless power signal, and the states are The packet to be transmitted by the electronic device 200 is acquired based on the digital data classified according to .

Hereinafter, a process in which the wireless power transmitter 100 obtains a power control message to be transmitted by the electronic device 200 from demodulated digital data will be described.

Referring to FIG. 11B , the power transmission control unit 112 detects an encoded bit from an envelope detected signal using a clock signal CLK. The detected encoded bit is encoded according to the bit encoding method used in the modulation process of the electronic device 200 side. In some embodiments, the bit encoding method may be non-return to zero (NRZ). In some embodiments, the bit encoding method may be bi-phase encoding.

For example, in some embodiments, the detected bit may be differential bi-phase (DBP) encoded. According to the DBP encoding, the power reception control unit 292 of the electronic device 200 has two state transitions to encode data bit 1 and one state transition to encode data bit 0. to have That is, data bit 1 is encoded so that a transition between the HI state and LO state occurs at the rising edge and the falling edge of the clock signal, and data bit 0 is HI at the rising edge of the clock signal. It may be encoded such that a transition between the state and the LO state occurs.

Meanwhile, the power transmission control unit 112 may obtain data in byte units by using a byte format constituting a packet from a bit string detected according to a bit encoding method. In some embodiments, the detected bit stream may be transmitted using an 11-bit asynchronous serial format as shown in FIG. 11C . That is, it may include a start bit indicating the start of a byte and a stop bit indicating the end of a byte, and may include data bits b0 to b7 between the start bit and the end bit. Also, a parity bit may be added for checking data errors. The byte unit data constitutes a packet including a power control message.

[In case of supporting in-band two-way communication]

As described above, in FIG. 9 , the wireless power receiver 200 transmits a packet using a carrier signal 10a formed by the wireless power transmitter 100, but the wireless power transfer The device 100 may also transmit data to the wireless power receiver 200 in a similar manner to the above.

That is, the power transmission control unit 112 may control the modulation/demodulation unit 113 to modulate data to be transmitted to the wireless power receiver 200 to be loaded on the carrier signal 10a. In this case, the power reception control unit 292 of the wireless power receiver 200 controls the modulation/demodulation unit 293 to obtain data from the modulated carrier signal 10a to perform demodulation. can

packet format

Hereinafter, a structure of a packet used in communication using a wireless power signal according to embodiments disclosed herein will be described.

12A, 12B, and 12C illustrate a packet including a power control message used in a wireless power transfer method according to embodiments disclosed herein.

Referring to FIG. 12A , the wireless power transmitter 100 and the electronic device 200 may transmit/receive data to be transmitted in the form of a command packet (command_packet) 510 . The command packet 510 may be configured to include a header 511 and a message 512 .

The header 511 may include a field indicating the type of data included in the message 512 . The size and type of the message may be determined based on a value indicated by a field indicating the type of the data.

Also, the header 511 may include an address field for identifying the sender of the packet. For example, the address field may indicate an identifier of the electronic device 200 or an identifier of a group to which the electronic device 200 belongs. When the electronic device 200 intends to transmit the packet 510, the electronic device 200 generates the packet 510 such that the address field of the packet 510 indicates its identification information. can do.

The message 512 includes data that the sender of the packet 510 intends to transmit. Data included in the message 512 may be a report, a request, or a response to the counterpart.

Meanwhile, in some embodiments, the command packet 510 may be configured as shown in FIG. 12B . The header 511 included in the command packet 510 may be expressed in a predetermined size. For example, the header 511 may have a size of two bytes.

The header 511 may be configured to include a destination address field. For example, the destination address field may have a size of 6 bits.

The header 511 may be configured to include an operation command field (OCF) or an operation group field (OGF). OGF is a value given to each group of commands for the electronic device 200 , and OCF is a value given to each command existing in each group including the electronic device 200 .

The message 512 may be expressed by dividing it into a parameter length field 5121 and a parameter value field 5122 . That is, the sender of the packet 510 may configure the message in the form of a length-value pair (5121a-5122a, etc.) of one or more parameters necessary to express the data to be transmitted.

Referring to FIG. 12C , the wireless power transmitter 100 and the electronic device 200 transmit the data in the form of a packet in which a preamble 520 and a checksum 530 for transmission are added to the command packet 510 . can send and receive

The preamble 520 is used for the wireless power transmitter 100 to perform synchronization with received data and to accurately detect the start bit of the command packet 510 . The preamble 520 may be configured such that the same bit is repeated. For example, the preamble 520 may be configured such that data bit 1 according to the DBP encoding is repeated 11 to 25 times.

The checksum 530 is used to detect errors that may occur in the command packet 510 while the power control message is being transmitted.

operation state ( Phases )

Hereinafter, operating states of the wireless power transmitter 100 and the wireless power receiver 200 will be described.

13 illustrates operating states of the wireless power transmitter 100 and the wireless power receiver 200 according to embodiments disclosed herein. Also, FIGS. 14 to 18 show the structures of packets including a power control message between the wireless power transmitter 100 and the wireless power receiver 200 .

Referring to FIG. 13 , the operating states of the wireless power transmitter 100 and the wireless power receiver 200 for wireless power transmission are a selection phase 610 and a detection phase 620 . , an identification and configuration phase 630 , and a power transfer phase 640 .

In the selection state 610, the wireless power transmitter 100 detects whether objects exist within a range capable of wirelessly transmitting power, and in the detection state 620, the wireless power transmitter 100 100) sends a detection signal to the detected object, and the wireless power receiver 200 sends a response to the detection signal.

Also, in the identification and setting state 630 , the wireless power transmitter 100 identifies the wireless power receiver 200 selected through previous states and acquires configuration information for power transmission. In the power transmission state 640 , the wireless power transmitter 100 transmits power to the wireless power receiver 200 while adjusting power transmitted in response to the control message received from the wireless power receiver 200 . transmit power.

Hereinafter, each operation state will be described in detail.

1) Select state ( Selection Phase )

The wireless power transmitter 100 in the selection state 610 performs a detection process to select the wireless power receiver 200 existing in the detection area. As described above, the sensing region refers to a region in which an object in the corresponding region can affect the power characteristics of the power converter 111 . Compared with the detection state 620 , the detection process for the selection of the wireless power receiver 200 in the selection state 610 includes receiving a response from the wireless power receiver 200 using a power control message. Instead of the method, the power conversion unit of the wireless power transmitter 100 detects a change in the amount of power for forming the wireless power signal and checks whether an object exists within a certain range. The detection process in the selection state 610 may be referred to as an analog detection process (analog ping) in that an object is detected using a wireless power signal without using a digital packet in the detection state 620, which will be described later. .

The wireless power transmitter 100 in the selection state 610 may detect that an object enters or leaves the detection area. In addition, the wireless power transmitter 100 can distinguish the wireless power receiver 200 capable of wirelessly transmitting power from among the objects within the detection area and other objects (eg, keys, coins, etc.). can

As described above, since the distance over which power can be wirelessly transmitted is different according to the inductive coupling method and the resonant coupling method, the sensing area in which an object is detected in the selection state 610 may be different from each other.

First, when power is transmitted according to the inductive coupling method, the wireless power transmitter 100 in the selection state 610 may monitor an interface surface (not shown) to detect the arrangement and removal of objects.

Also, the wireless power transmitter 100 may detect the position of the wireless power receiver 200 placed on the interface surface. As described above, the wireless power transmitter 100 configured to include one or more transmitting coils enters the detection state 620 in the selection state 610 and uses each coil in the detection state 620 . Thus, it is possible to check whether a response to the detection signal is transmitted from the object or to enter the identification state 630 thereafter to check whether identification information is transmitted from the object. The wireless power transmitter 100 may determine a coil to be used for wireless power transmission based on the sensed position of the wireless power receiver 200 acquired through this process.

In addition, when power is transmitted according to the resonance coupling method, the wireless power transmitter 100 in the selection state 610 changes one or more of the frequency, current, and voltage of the power converter due to an object in the sensing area. The object can be detected by detecting it.

Meanwhile, the wireless power transmitter 100 in the selected state 610 may detect an object by at least one of the detection methods according to the inductive coupling method and the resonant coupling method. The wireless power transmitter 100 performs an object detection process according to each power transmission method, and then detects the object from among the combination methods for wireless power transmission in order to proceed to other states 620 , 630 , and 640 . You can choose one way.

On the other hand, in the wireless power transmitter 100 in the selection state 610, the wireless power signal formed to detect an object and digital detection, identification, setting and power in the subsequent states 620, 630, 640 The wireless power signal formed for transmission may have different characteristics such as frequency and strength. This means that the selection state 610 of the wireless power transmitter 100 corresponds to an idle phase for detecting an object, so that the wireless power transmitter 100 reduces power consumption while in standby or efficiently This is to enable a specialized signal to be generated for object detection.

2) detection status ( Ping Phase )

The wireless power transmitter 100 in the detection state 620 performs a process of detecting the wireless power receiver 200 existing in the detection area through a power control message. Compared with the detection process of the wireless power receiver 200 using the characteristics of the wireless power signal in the selection state 610 , the detection process in the detection state 620 may be called a digital ping process. have.

In the detection state 620 , the wireless power transmitter 100 forms a wireless power signal for detecting the wireless power receiver 200 , and a wireless power signal modulated by the wireless power receiver 200 . and obtains a power control message in the form of digital data corresponding to a response to the detection signal from the demodulated wireless power signal. The wireless power transmitter 100 may recognize the wireless power receiver 200 as a target of power transmission by receiving a power control message corresponding to a response to the detection signal.

The detection signal formed by the wireless power transmitter 100 in the detection state 620 to perform a digital detection process is a wireless power signal formed by applying a power signal of a specific operating point for a predetermined time. can The operating point may mean a frequency, a duty cycle, and an amplitude of a voltage applied to a transmission coil (Tx coil). The wireless power transmitter 100 generates the detection signal generated by applying the power signal of the specific operation point for a predetermined time, and attempts to receive a power control message from the wireless power receiver 200 . have.

Meanwhile, the power control message corresponding to the response to the detection signal may be a message indicating the strength of the wireless power signal received by the wireless power receiver 200 . For example, the wireless power receiver 200 may include a signal strength packet 5100 including a message indicating the strength of a received wireless power signal as a response to the detection signal as shown in FIG. 14 . ) can be transmitted. The packet 5100 may be configured to include a header 5120 indicating the packet indicating signal strength and a message 5130 indicating the strength of the power signal received by the wireless power receiver 200 . The strength of the power signal in the message 5130 may be a value indicating a degree of coupling or inductive coupling for power transmission between the wireless power transmitter 100 and the wireless power receiver 200 . have.

After the wireless power transmitter 100 receives the response message to the detection signal and discovers the wireless power receiver 200 , the digital detection process is extended to enter the identification and detection state 630 . have. That is, the wireless power transmitter 100 may receive the power control message required in the identification and detection state 630 by maintaining the power signal of the specific operation point after discovering the wireless power receiver 200 . have.

However, when the wireless power transmitter 100 does not find the wireless power receiver 200 capable of transmitting power, the operating state of the wireless power transmitter 100 returns to the selection state 610 . can

3) Identification and setting status ( identification and Configuration Phase )

The wireless power transmitter 100 in the identification and setting state 630 may receive identification information and/or configuration information transmitted from the wireless power receiver 200 to control power transfer efficiently.

In the identification and setting state 630 , the wireless power receiver 200 may transmit a power control message including its own identification information. To this end, the wireless power receiver 200 may transmit, for example, an identification packet 5200 including a message indicating identification information of the wireless power receiver 200 as shown in FIG. 15A . have. The packet 5200 may be configured to include a header 5220 indicating that it is a packet indicating identification information and a message 5230 including identification information of the wireless power receiver. The message 5230 includes information 2531 and 5232 indicating the version of the protocol for wireless power transmission, information 5233 identifying the manufacturer of the wireless power receiver 200, and information indicating the presence or absence of an extension device identifier. 5234 and a basic device identifier 5235 . In addition, when it is indicated that the extended device identifier is present in the information 5234 indicating the presence or absence of the extended device identifier, an Extended Identification Packet 5300 including the extended device identifier as shown in FIG. 15B is transmitted. may be transmitted separately. The packet 5300 may be configured to include a header 5320 indicating that it is a packet indicating an extended device identifier and a message 5330 including an extended device identifier. In this case, when the extended device identifier is used, the manufacturer's identification information 5233, the basic device identifier 5235, and the extended device identifier 5330 are used to identify the wireless power receiver 200. information may be used.

In the identification and setting state 630 , the wireless power receiver 200 may transmit a power control message including information on the expected maximum power. To this end, the wireless power receiver 200 may transmit, for example, a configuration packet 5400 as shown in FIG. 16 . The packet may be configured to include a header 5420 indicating that it is a configuration packet and a message 5430 including information on the expected maximum power. The message 5430 includes a power class 5431, information on expected maximum power 5432, an indicator 5433 indicating a method for determining the current of a primary cell on the wireless power transmitter side, and the number of optional configuration packets ( 5434). The indicator 5433 may indicate whether the current of the main cell on the side of the wireless power transmitter is to be determined as specified in the protocol for wireless power transmission.

Meanwhile, the wireless power transmitter 100 may generate a power transfer contract used for power charging with the wireless power receiver 200 based on the identification information and/or setting information. The power transfer protocol may include limits of parameters that determine the power transfer characteristics in the power transfer state 640 .

The wireless power transmitter 100 may end the identification and setting state 630 before entering the power transfer state 640 and return to the selection state 610 . For example, the wireless power transmitter 100 may end the identification and setting state 630 to find another wireless power receiver capable of wirelessly receiving power.

4) Power transmission status ( Power Transfer Phase )

In the power transmission state 640 , the wireless power transmitter 100 transmits power to the wireless power receiver 200 .

The wireless power transmitter 100 receives a power control message from the wireless power receiver 200 while transmitting power, and adjusts characteristics of power applied to the transmitting coil in response to the received power control message. can For example, a power control message used to adjust the power characteristic of the transmitting coil may be included in a control error packet 5500 as shown in FIG. 17 . The packet 5500 may be configured to include a header 5520 indicating that it is a control error packet and a message 5530 including a control error value. The wireless power transmitter 100 may adjust the power applied to the transmitting coil according to the control error value. That is, the current applied to the transmitting coil may be adjusted to be maintained when the control error value is 0, decreased when the control error value is 0, and increased when the control error value is positive.

In the power transfer state 640 , the wireless power transmitter 100 may monitor parameters in a power transfer contract generated based on the identification information and/or configuration information. As a result of monitoring the parameters, when the power transmission with the wireless power receiver 200 violates restrictions included in the power transfer protocol, the wireless power transmitter 100 cancels the power transmission and It may return to the selection state 610 .

The wireless power transmitter 100 may terminate the power transmission state 640 based on the power control message transmitted from the wireless power receiver 200 .

For example, when the charging of the battery is completed while the wireless power receiver 200 is charging the battery using the transmitted power, the power requesting to stop the wireless power transmission to the wireless power transmitter 100 . Control messages can be transmitted. In this case, after receiving the message requesting to stop the power transmission, the wireless power transmitter 100 may end wireless power transmission and return to the selection state 610 .

As another example, the wireless power receiver 200 may transmit a power control message requesting renegotiation or reconfiguration in order to update an already generated power transfer protocol. The wireless power receiver 200 may transmit a message requesting renegotiation of the power transfer protocol when more or less power than the currently transmitted power is required. In this case, after receiving the message requesting renegotiation of the power transfer protocol, the wireless power transmitter 100 may end wireless power transmission and return to the identification and setting state 630 .

To this end, the message transmitted by the wireless power receiver 200 may be, for example, an End Power Transfer Packet 5600 as shown in FIG. 18 . The packet 5600 may be configured to include a message 5630 including a header 5620 indicating that it is a power transmission stop packet and a power transmission stop code indicating the reason for the interruption. The power transmission stop code is a charge complete (Charge Complete), internal error (Internal Fault), over temperature (Over Temperature), over voltage (Over Voltage), over current (Over Current), battery failure (Battery Failure), reset (Reconfigure), Either no response or unknown error may be indicated.

Communication method of multiple electronic devices

Hereinafter, a method in which one or more electronic devices perform communication using a wireless power signal from one wireless power transmitter will be described.

19 is a conceptual diagram illustrating a method in which a wireless power transmitter transmits power to one or more wireless power receivers.

The wireless power transmitter 100 may transmit power for one or more wireless power receivers 200 and 200'. Although two electronic devices 200 and 200 ′ are illustrated in FIG. 19 , the method according to the embodiments disclosed herein is not limited to the number of illustrated electronic devices.

The active area and the sensing area are different according to the wireless power transfer method of the wireless power transmitter 100 . Accordingly, the wireless power transmitter 100 determines whether there is a wireless power receiver disposed in the active area or detection area of the resonance coupling method, or whether the wireless power receiver disposed in the active area or detection area of the inductive coupling method is detected. It can be determined whether it exists or not. According to the determination result, the wireless power transmitter 100 supporting each wireless power transfer method may change the power transfer method for each wireless power receiver.

In the wireless power transmission according to the embodiments disclosed in this specification, when the wireless power transmitter 100 transmits power for one or more electronic devices 200 and 200 ′ using the same wireless power transfer method, the electronic device The devices 200 and 200' can communicate through the wireless power signal without colliding with each other.

As shown in FIG. 19 , the wireless power signal 10a formed by the wireless power transmitter 100 arrives at the first electronic device 200 ′ and the second electronic device 200 . The first electronic device 200 ′ and the second electronic device 200 may transmit a power control message using the formed wireless power signal.

The first electronic device 200 ′ and the second electronic device 200 operate as a power receiver for receiving a wireless power signal. The power receiver according to the embodiments disclosed herein includes: power receivers 291' and 291 for receiving the formed wireless power signal; modulation and demodulation units 293' and 293 for performing modulation and demodulation on the received wireless power signal; and control units 292 ′ and 292 for controlling each component of the power receiver.

In the above, the wireless power transmission/reception method of the present invention has been described focusing on the WPC standard. Furthermore, the present invention proposes a wireless power transmitter for medium power, a wireless power receiver, and a wireless charging system. Here, the medium power wireless power transmitter means a wireless power transmitter that transmits medium power wireless power to the wireless power receiver. Furthermore, the wireless power receiver for medium power means a wireless power receiver that receives the medium power transmitted from the wireless power transmitter.

Here, the medium power means power of several tens of W or more, and an appliance using such medium power is, for example, a juicer (citrus press), a hand blender (handblender), a grinder (blender), It may be a juicer, a smart pan, an electric kettle, a rice cooker, and the like.

Hereinafter, in a wireless power transmitter for transmitting medium power, a method of controlling power while maintaining system stability will be described. The stability of the system may be related to power transfer efficiency, protection of components of a wireless power transmitter, and electromagnetic compatibility (EMC) issues.

20 is a block diagram illustrating the configuration of a wireless power transmitter according to an embodiment of the present invention. 21 is a circuit diagram illustrating the block diagram of FIG. 20 in more detail. 22 and 23 are structural diagrams showing the structures of different phase sensing units. 24 is a circuit diagram showing the structure of a half-bridge inverter. 25A and 25B are timing diagrams illustrating a method of switching the circuit of FIG. 24 . 26 is a circuit diagram showing the structure of a full-bridge inverter. 27A, 27B and 28 are timing diagrams illustrating different methods of switching the circuit of FIG. 26 .

In order to control the power of the medium power level or higher, the wireless power transmitter may use a full-bridge inverter. In this case, the wireless power transmitter according to the present invention proposes a method of controlling a full-bridge inverter for system stability.

Referring to Figure 20, the present invention, a power conversion unit 1111 including a coil and a capacitor to convert a current into magnetic flux to transmit power, the inverter consisting of a full-bridge inverter to control the power converted by the power conversion unit A phase detection unit (or phase detection unit, 300) for detecting at least one phase of a current flowing through the inductor of the unit 1112 and the power conversion unit and a voltage applied to the capacitor, and the power conversion unit, the inverter unit, and the phase detection unit and a control unit (or a power transmission control unit 112 ) for controlling power.

The power converter 1111 may include a coil and a capacitor, and may generate a wireless power signal using an electromagnetic field or a magnetic field for power transmission.

The inverter unit 1112 may be configured as a half-bridge inverter or a full-bridge inverter. The inverter unit 1112 changes the operating frequency of the half-bridge inverter or the full-bridge inverter through the switch timing of a plurality of switches constituting the half-bridge inverter or the full-bridge inverter, in the power conversion unit 1111 It is possible to control the transmitted power.

The plurality of switches may use a semiconductor device. For example, the plurality of switches may include a transistor, a field effect transistor (FET), an intelligent power switching (IPS) device, a metal oxide semiconductor field effect transistor (MOSFET), an electronic relay, and an insulated gate bipolar transistor (IGBT), etc. this can be

The phase detector 300 may detect a phase of at least one of a voltage of a capacitor constituting the power converter 1111 and a current of an inductor. In addition, the phase detection unit 300 may detect at least one phase of the voltage of the capacitor and the current of the inductor, and transmit phase information corresponding to the detected phase to the control unit 112 .

For example, as shown in FIG. 22 , when the phase detection unit 300 detects the current of the inductor, the phase detection unit 300 may include a current converter and a comparator for sensing the current. That is, the phase detection unit 300 detects the current flowing through the power converter 1111 through the current converter, converts the current flowing through the current converter into current phase information through a comparator, and the current phase information may be transmitted to the controller 180 .

As another example, as shown in FIG. 23 , when the phase detection unit 300 detects the voltage of the capacitor, the phase detection unit 300 may include a voltage detector and a comparator for voltage detection. At this time, the phase detector detects the voltage applied to the power converter 1111 through the voltage detector, changes the voltage flowing through the voltage detector to voltage phase information through the comparator, and converts the voltage phase information to the controller (180).

The control unit 112 may control the power conversion unit 1111 , the inverter unit 1112 , and the phase detection unit 300 . For example, the controller 112 may control the power transmitted from the power converter 1111 . More specifically, the control unit 112 changes the operating frequency of the inverter unit 1112 based on the amount of power received from the wireless power receiver receiving wireless power, thereby transmitting the power from the power conversion unit 1111 . power can be adjusted.

Also, the control unit 112 may control the inverter unit based on the phase information transmitted from the phase detection unit 300 . More specifically, the control unit 112 may determine a switching time of the inverter unit 1112 according to the phase information.

The switching time may be an on time when each switch constituting the inverter unit 1112 is turned on and an off time at which each switch constituting the inverter unit is turned off.

On the other hand, each of the switches constituting the inverter unit 1112 do not affect the overall stability of the wireless power transmitter system, and must be turned on/off. This is called soft switching or zero voltage switching. The soft switching is a method of suppressing an excessive voltage or inrush current flowing through the switch by performing on/off of a switch through which the AC power flows near the instantaneous value of the AC power to zero. Through this, the present invention can maintain the stability of the wireless charging system even when transmitting power of medium power or higher.

Also, the control unit 112 may control the inverter unit 1112 based on the amount of power transmitted from the power conversion unit 1111 . More specifically, the control unit 112 may determine an off time of a switch constituting the inverter unit 1112 based on the amount of power transmitted from the power conversion unit 1111 .

The amount of power transmitted from the power converter 1111 may be received from the wireless power receiver 200 before and during transmission of the power. More specifically, the wireless power receiver 200 may transmit information on the amount of power to be received through a wireless power signal in a setting and identification state and a power transmission state.

In this case, the control unit 112 may determine a switch-off time of the inverter unit 1112 based on the amount of power information received from the wireless power receiver. For example, when the power amount information is the first power amount information, the control unit 112 determines the switch-off time as the first off time, and the power amount information is more second power amount information than the first power amount information. In this case, the switch-off time may be determined as the second off time.

Meanwhile, the wireless power receiver may transmit the power amount information to the wireless power transmitter while the wireless power reception continues. In this case, the control unit 112 may determine the off time of the switch again based on the amount of power information received during the transmission of the power. For example, the controller 180 determines a first time point as an OFF time point of the switch based on the first power amount information, and then, when the second power amount information is received from the wireless power receiver, the second power amount information Based on , the second time point may be changed to an OFF time point of the switch.

Through this, in the present invention, by adjusting the effective duty of the inverter unit 1112, while controlling the power, it is possible to maintain the stability of the system.

Hereinafter, a method in which the inverter unit 1112 determines a switching timing for each case of a half-bridge inverter and a full-bridge inverter will be described in more detail.

24 is a circuit diagram in which the inverter unit 1112 is configured as a half-bridge inverter. 25A and 25B are timing diagrams illustrating a final output voltage of the inverter unit 1112 of FIG. 24 and a driving time of each switch.

Referring to the first drawing of FIG. 25 , the inverter unit 1112 may output an AC current flowing through the power converting unit 1111 and an AC voltage flowing through the power converting unit 1111 .

In this case, the switching timing of the two switches constituting the inverter unit 1112 may be determined according to the phase information received from the phase detection unit 300 . More specifically, the control unit 112 may determine the on time of the two switches as a time prior to the time when the phase according to the phase information becomes 0.

For example, as shown in FIG. 24 , the half-bridge inverter may include a first switch and a second switch. At this time, as shown in FIG. 25A , when the first switch is switched from an on state to an off state, the control unit 112 controls the phase of the coil current at the time when the first switch is turned off and the flow in the coil. It is possible to detect a point in time before the phase of the current is changed. Here, the phase shift may mean that the phase is changed from a positive value to a negative value or from a negative value to a positive value. For example, as shown in FIG. 25A , when the phase of the coil current at the time when the first switch is turned off has a positive value, the time at which the phase of the current flowing through the coil is switched, the phase is negative It may mean a time point immediately before having a value of , that is, a time point at which the phase becomes 0. On the contrary, when the phase of the coil current at the time when the first switch is turned off has a negative value, the time at which the phase of the current flowing in the coil is switched is a time immediately before the phase has a positive value, that is, , may mean a point in time when the phase becomes 0.

In this case, the control unit 112 may determine the on time of the second switch within a time interval from the time when the first switch is turned off until the time when the phase of the current flowing in the coil is switched. That is, in the present invention, by determining the on time of the second switch within the time period from the time when the first switch is turned off to the time when the phase of the current flowing through the coil is switched, the excessive current is supplied to the second switch flow can be prevented. Here, a time interval (hatched time interval) from the time when the first switch is turned off until the time when the phase of the current flowing through the coil is switched may be called a don't care interval.

For example, as shown in FIG. 25A , the controller 112 may determine the on time of the second switch as a time point t just before the phase of the current flowing through the coil becomes zero. In this case, the control unit 112 may determine a time point at which the phase difference between the voltage and the current of the power converter 1111 is the smallest among the unrelated sections as the on time point of the second switch. For example, the control unit 112 may determine the on time of the second switch as a time point t before a predetermined time period Δt from a time point at which the current flowing through the coil becomes zero during the irrelevant period. For the predetermined time period Δt, an optimal time period may be experimentally selected.

Also, the control unit 112 may determine an off time point of the second switch based on the amount of power transmitted from the power conversion unit 1111 . Here, the amount of power information may be determined by a load amount and a charge amount of the wireless power receiver.

More specifically, the wireless power transmitter may receive power amount information from the wireless power receiver before transmitting power. In this case, the control unit 112 may detect an effective duty of the switches constituting the inverter unit 1112 based on the received power amount information. The effective duty may be a time interval having a valid signal in the pulse signal.

The control unit 112 may determine an off time point of the second switch to have the detected effective duty. In this case, the OFF timings of the first and second switches are not related to soft switching and are not related to each other.

For example, as shown in FIG. 25A , the control unit 112 may determine an off time point of the first switch based on the first amount of power information. Conversely, as shown in FIG. 25B , the control unit 112 may determine the off time of the first switch as a second time later than the first time, based on information on the second amount of power greater than the first amount of power. have.

The on/off timing of the first switch may also be determined in the same manner as the on/off timing of the second switch.

Hereinafter, a case in which the inverter unit 1112 is a full-bridge inverter will be described in more detail with reference to the drawings.

The inverter unit 1112 may be a full-bridge inverter including four switches M1, M2, M3, and M4. 26 is a circuit diagram illustrating the full-bridge inverter. In the full-bridge inverter, a first switch (M1) and a second switch (M2) are connected in series, the third switch (M3) and a fourth switch (M4) are connected in series, and the first and second switches (M4) are connected in series. The second switches M1 and M2 and the third and fourth switches M3 and M4 may be connected in parallel to each other.

In this case, the controller 180 may determine the on/off timing of each of the switches in the same manner as the half-bridge inverter. That is, in the present invention, the full-bridge inverter may also perform soft switching.

More specifically, the control unit 112 may detect that the first switch M1 is turned off while the first switch M1 and the fourth switch M4 are turned on. At this time, the control unit 112 is a time interval (hatching) from the time the first switch (M1) is turned off to just before the phase of the current flowing in the coil at the time the first switch (M1) is turned off is switched. time period) may be determined as the ON time of the second switch M2. For example, as shown in FIG. 27A , the second switch M2 may be turned on at t1 just before the phase of the coil current becomes zero.

In addition, the control unit 112 determines the on time of the fourth switch M4 in the time interval from the time when the third switch M3 is turned off to the time before the phase of the current flowing through the coil becomes 0 can decide For example, as shown in FIG. 27A , the on time point of the fourth switch may be t2.

In addition, the control unit may control the inverter unit differently from FIG. 27A . For example, as shown in FIG. 28 , the controller 112 may determine the on time of the first switch by the second switch and the on time of the third switch by the fourth switch. In this case, the control unit 112 may determine the on time of the switch in the same manner as in FIG. 27A .

Meanwhile, the control unit 112 may determine an off time of the switches of the full-bridge inverter, as described in the half-bridge inverter. That is, the controller 112 may determine an off time of the switches of the full-bridge inverter based on the amount of power received from the wireless power receiver.

That is, referring to FIG. 27A , the control unit 112 may determine the first time point as the first switch-off time point based on the first power amount information. Also, referring to FIG. 27B , the control unit 112 may determine a second time point later than the first time point as an OFF time point of the first switch, based on information on a second amount of power greater than the first amount of power. That is, as the amount of power information increases, the control unit 112 may delay the turn-off time of the switch so that the effective duty of the pulse increases.

Furthermore, the control unit 112 may periodically receive power amount information from the wireless power receiver while the power transmission continues. In this case, the control unit 112 may determine an off time of the switches based on the periodically received power amount information.

For example, when the power amount information is changed from the first power amount information to the second power amount information, the control unit 112 may change the off time of the switch from the first time point to the second time point.

In the above, a method for controlling the amount of power of the wireless power transmitter has been described. According to the present invention, by determining the on/off timing of the plurality of switches constituting the inverter unit based on the phase and wattage information of the current or voltage of the power converter, it is possible to maintain soft switching and control the amount of wattage.

In addition, the present invention can ensure the stability of the entire system by maintaining soft switching.

The configuration of the wireless power transmitter according to the embodiments disclosed herein is applicable to devices such as docking stations, terminal cradle devices, and other electronic devices, except when applicable only to wireless chargers. It will be readily apparent to those skilled in the art that this may be the case.

The scope of the present invention is not limited to the embodiments disclosed herein, and the present invention may be modified, changed, or improved in various forms within the scope of the spirit and claims of the present invention.

Claims (14)

a power converter formed of a coil and a capacitor to convert current into magnetic flux to transmit power to the wireless power receiver;
a phase detector connected to the power converter to detect a phase of at least one of a current flowing through the coil and a voltage of the capacitor;
an inverter unit connected to the power conversion unit and formed of at least two switches to generate an AC voltage for controlling a resonant frequency of power transmitted from the power conversion unit; and
A control unit for controlling the power conversion unit, the phase detection unit, and the inverter unit together to adjust the output of the power transmitted from the power conversion unit,
the control unit
Based on the phase of at least one of the current and voltage detected by the phase detection unit, a time period in which at least one of the at least two switches forming the inverter unit can be turned on is detected, and the at least one switch is turned on Wireless power transmitter, characterized in that for determining. delete According to claim 1,
The time period during which it is possible to turn on the at least one switch is,
Wireless power transmitter, characterized in that determined based on the time when the phase of the current detected by the phase detector becomes zero. According to claim 1,
The inverter unit,
a first switch;
Consists of a second switch connected in series with the first switch,
the control unit
When the first switch is switched from an on state to an off state, the second switch is turned on within a time interval from the time when the first switch is turned off to the time before the phase of the coil current detected by the phase detection unit becomes 0 A wireless power transmitter, characterized in that it does. a power converter formed of a coil and a capacitor to convert current into magnetic flux to transmit power to the wireless power receiver;
a phase detector connected to the power converter to detect a phase of at least one of a current flowing through the coil and a voltage of the capacitor;
an inverter unit connected to the power conversion unit and formed of at least two switches to generate an AC voltage for controlling a resonant frequency of power transmitted from the power conversion unit; and
A control unit for controlling the power conversion unit, the phase detection unit, and the inverter unit together to adjust the output of the power transmitted from the power conversion unit,
the control unit
The off-time of the at least two switches is a wireless power transmitter, characterized in that determined by the amount of power transmitted to the wireless power receiver. 6. The method of claim 5,
the control unit
and determining an off time point at which at least one of the at least two switches is switched from an on state to an off state based on the wireless power signal received from the wireless power receiver. 7. The method of claim 6,
The wireless power signal received from the wireless power receiver includes information on the amount of power required by the receiver,
the control unit
When the amount of power included in the wireless power signal is the first amount of power, the first time is determined as an off time,
When the amount of power included in the wireless power signal is a second amount of power greater than the first amount of power, a second time point later than the first time point is determined as an OFF time point so as to increase the effective duty of the at least one switch A wireless power transmitter. 7. The method of claim 6,
The wireless power signal received from the wireless power receiver is periodically received at a preset time interval while power is transmitted to the receiver by the power converter,
the control unit
Based on the periodically received wireless power signal, the wireless power transmitter, characterized in that for changing the off-time of the at least one switch. According to claim 1,
The inverter unit
a first switch and a second switch connected in series with each other; and
A third switch and a fourth switch connected in parallel with the first switch and the second switch, and a third switch and a fourth switch connected in series with each other,
the control unit
determining an on time of the second switch according to an off time of the first switch,
The wireless power transmitter, characterized in that the on-time of the fourth switch is determined according to the off-time of the third switch. 10. The method of claim 9,
The off-time of the first switch and the third switch is a wireless power transmitter, characterized in that determined by the amount of power transmitted to the wireless power receiver. delete delete delete delete

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