KR20190090918A - Adaptive Wireless Power Reception Method and Apparatus - Google Patents

Abstract

The present invention relates to a wireless power transmission method and an apparatus thereof. According to an embodiment of the present invention, the wireless power transmission apparatus comprises: an inverter; a transmission coil wirelessly transmitting an alternating current power signal received from the inverter; a receiver detector generating first to second output signals by using an inverter input voltage applied to at least the inverter, and a coil voltage applied to the transmission coil; and a main controller distinguishing an object arranged in a charging region based on the first to second output signals and controlling the inverter input voltage in accordance with a distinguishing result. Therefore, the present invention provides the wireless power transmission apparatus which is excellent in charging efficiency and heat dissipation performance.

Description

Adaptive Wireless Power Reception Method and Apparatus

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless power transmission technology, and more particularly, to a wireless power transmission method capable of adaptively controlling an inverter input voltage (ie, V_RAIL) according to the type and state of an object disposed in a charging region. And to an apparatus.

Energy transmission using wireless may be classified into a magnetic induction method, an electromagnetic resonance method, and an RF transmission method using a short wavelength radio frequency.

The magnetic induction method uses the phenomenon that magnetic flux generated at this time causes electromotive force to other coils when two coils are adjacent to each other and current flows to one coil, and is rapidly commercialized in small devices such as mobile phones. Is going on. Magnetic induction is capable of transmitting power of up to several hundred kilowatts (kW) and has high efficiency, but the maximum transmission distance is less than 1 centimeter (cm).

The magnetic resonance method is characterized by using an electric or magnetic field instead of using electromagnetic waves or current.

Since the magnetic resonance method is hardly affected by the electromagnetic wave problem, it has the advantage of being safe for other electronic devices or the human body. On the other hand, it can be utilized only in limited distances and spaces, and has a disadvantage in that energy transmission efficiency is rather low.

The short wavelength wireless power transmission scheme—simply, the RF transmission scheme— takes advantage of the fact that energy can be transmitted and received directly in the form of RadioWave.

This technology is a wireless power transmission method of the RF method using a rectenna, a compound word of an antenna and a rectifier (rectifier) refers to a device that converts RF power directly into direct current power.

In other words, the RF method is a technology that converts AC radio waves to DC and uses them. Recently, research on commercialization has been actively conducted as efficiency is improved.

Wireless power transfer technology can be used in various industries, such as the mobile, IT, railroad and consumer electronics industries.

The conventional wireless power transmitter providing 12 watts of wireless charging provided the same input voltage to the inverter in a standby state for receiver sensing and a charging state for wireless power transmission, that is, V_rail. .

Recently, research on a wireless power transmitter providing high power charging has been actively conducted, and a wireless power receiver requiring high power charging of more than 60 watts (W) has been developed.

However, in order to provide a low heat generation, high efficiency wireless power transmission apparatus, it is necessary to perform high voltage / low current wireless power transmission.

If the wireless power transmitter wirelessly transmits a high voltage / low current power signal in the standby state, there is a problem that not only the standby power consumption is increased but also the risk that the peripheral electronic device is damaged.

On the other hand, when a low voltage / high current power signal is transmitted for the high power charging receiver, not only normal charging is possible but also the receiver may be damaged due to high heat generation.

The present invention has been devised to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide an adaptive wireless power transmission method and apparatus.

Another object of the present invention is to provide a wireless power transmission method and apparatus capable of adaptively controlling an inverter input voltage according to the type and state of an object disposed in a charging region.

Still another object of the present invention is to provide a wireless power transmission method and apparatus having excellent charging efficiency and heat generation characteristics.

Technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned above will be clearly understood by those skilled in the art from the following description. Could be.

The present invention can provide a method and apparatus for wireless power transmission.

A wireless power transmitter according to an embodiment of the present invention uses an inverter and a transmission coil for wirelessly transmitting an AC power signal received from the inverter, at least an inverter input voltage applied to the inverter, and a coil voltage applied to the transmission coil. A main controller for identifying a receiver disposed to generate first to second output signals and an object disposed in a charging region based on the first to second output signals, and controlling the inverter input voltage according to the identification result. It may include.

Here, when the main controller detects a receiver disposed in the charging region based on the first to second output signals in a standby state, the main controller may increase the inverter input voltage from the first voltage to the second voltage to charge the receiver. .

In addition, when detecting that the receiver disposed in the charging region is removed based on the first to second output signals, the main controller drops the inverter input voltage from the second voltage to the first voltage during the charging. Can enter the standby state.

The wireless power transmitter may be configured to convert a voltage input from a power source to generate the first voltage, and to switch the ON / OFF control of the first voltage applied to the inverter and the control of the main controller. It may further include an inverter input voltage controller for controlling the switch.

In addition, when the receiver is disposed in the charging area in the standby state, the switch is turned on, and when the receiver is removed during charging, the switch may be turned off.

In this case, the receiver may have a power class of 60W.

In addition, the first voltage may be 5 V or less, and the second voltage may be 300 V or more.

In addition, the first to second output signals may be generated by further using a reference voltage.

Here, the reference voltage may be an output voltage of the converter.

In addition, the first voltage may be generated when an output voltage of the converter passes through a diode.

In addition, the diode may be a protection circuit that blocks the second voltage passing through the switch from being applied to the main controller and the converter.

In addition, the receiver detector may include a first comparator and a second comparator, and the first to second output signals may be outputs of the first comparator and outputs of the second comparator, respectively.

The output of the first comparator may be determined based on the inverter input voltage and the coil voltage, and the output of the second comparator may be determined based on the coil voltage and the reference voltage.

In addition, the receiver detector is connected to the first to second voltage control circuit and the first to second voltage control circuit for dropping the level of the inverter input voltage and the coil voltage under the control of the main controller, respectively, the voltage follower And a first to third filter and a smoothing circuit for converting the coil voltage into direct current, respectively. have.

In addition, the inverter input voltage is connected to the first input terminal of the first comparator through the first voltage control circuit, the first buffer, and the first filter, the coil voltage is the smoothing circuit, the second A voltage control circuit, the second buffer, and the second filter to be connected to the second input terminal of the first comparator and the first input terminal of the second comparator; and the reference voltage is passed through the third filter. It may be connected to the second input terminal of the second comparator.

In addition, when the output of the first comparator and the output of the second comparator are both first values in the standby state, the main controller may determine that the receiver is disposed in the charging region.

In addition, when the output of the first comparator and the output of the second comparator are both second values in the standby state, the main controller may determine that the foreign material is disposed in the charging region.

In addition, the output of the first comparator and the output of the second comparator are both changed to the second value in the charging state, and the main controller may determine that the receiver being charged is removed from the charging region.

Here, the first value may be HIGH and the second value may be LOW.

The above aspects of the present invention are only some of the preferred embodiments of the present invention, and various embodiments in which the technical features of the present invention are reflected will be described in detail below by those skilled in the art. Can be derived and understood.

The effects on the method, apparatus and system according to the present invention are described as follows.

The present invention has the advantage of providing an adaptive wireless power transmission method and apparatus.

In addition, the present invention has the advantage of providing a wireless power transmission method and apparatus that enables high power charging by adaptively controlling the inverter input voltage according to the type and state of the object disposed in the charging region.

In addition, the present invention has the advantage of providing a wireless power transmission method and apparatus that can prevent the damage to the receiver by providing the inverter input voltage differentially in the standby state and the charged state.

In addition, the present invention has the advantage of providing a wireless power transmission method and apparatus excellent in charging efficiency and heat generation characteristics.

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

1 is a block diagram illustrating a wireless charging system according to an embodiment of the present invention.
2 is a block diagram illustrating a wireless charging system according to another embodiment of the present invention.
3 is a block diagram illustrating a structure of a wireless power transmitter according to an embodiment of the present invention.
FIG. 4 is a block diagram illustrating a structure of a wireless power receiver interworking with the wireless power transmitter according to FIG. 3.
5A is a block diagram illustrating an internal structure of a wireless power transmitter having a switched mode power supply according to an embodiment of the present invention.
5B is a block diagram illustrating an internal structure of a wireless power transmitter having a DC / DC converter according to an embodiment of the present invention.
6 is a state transition diagram for explaining a wireless power transmission procedure according to an embodiment of the present invention.
7 is a view for explaining the structure of a high power wireless power transmission apparatus according to an embodiment of the present invention.
8 is a block diagram illustrating a configuration and a connection relationship between a main controller and a receiver detector of a wireless power transmitter according to an embodiment of the present invention.
9 is a circuit diagram illustrating a detailed configuration of a main controller and a receiver detector of a wireless power transmission apparatus according to an embodiment of the present invention.
10 is an experimental result table showing a receiver detection result according to a comparator output voltage of a receiver detector according to an embodiment of the present invention.
FIG. 11 is an experimental result table showing a sensing result according to a comparator output voltage of a receiver detector according to another exemplary embodiment.
12A to 12B are diagrams for describing a detailed configuration of the first voltage control circuit disclosed in FIGS. 8 to 9 according to one embodiment of the present invention.
13A to 13B are diagrams for describing a detailed configuration of the second voltage control circuit disclosed in FIGS. 8 to 9 according to one embodiment of the present invention.

Hereinafter, an apparatus and various methods to which embodiments of the present invention are applied will be described in more detail with reference to the accompanying drawings. The suffixes "module" and "unit" for components used in the following description are given or used in consideration of ease of specification, and do not have distinct meanings or roles from each other.

In the description of the embodiments, where it is described as being formed on the "top" or "bottom" of each component, the top (bottom) or the bottom (bottom) is the two components are in direct contact with each other or One or more other components are all included disposed between the two components. In addition, when expressed as "up (up) or down (down)" may include the meaning of the down direction as well as the up direction based on one component.

In the description of the embodiment, a device equipped with a function for transmitting wireless power on the wireless charging system is a wireless power transmitter, a wireless power transmitter, a wireless power transmitter, a wireless power transmitter, a transmitter, a transmitter, a transmitter for convenience of description. , A transmitter, a wireless power transmitter, a wireless power transmitter, and the like will be used interchangeably.

In addition, as a representation of a device equipped with a function for receiving wireless power from the wireless power transmitter, for convenience of description, a wireless power receiver, a wireless power receiver, a wireless power receiver, a wireless power receiver, a receiver terminal, a receiver, Receivers, receivers and the like can be used interchangeably.

The transmitter according to the present invention may be configured in a pad form, a cradle form, an access point (AP) form, a small base station form, a stand form, a ceiling buried form, a wall hanging form, and the like. You can also transfer power.

To this end, the transmitter may comprise at least one wireless power transmission means.

Herein, the wireless power transmission means may use various wireless power transmission standards based on an electromagnetic induction method that generates a magnetic field in the power transmitter coil and charges using the electromagnetic induction principle in which electricity is induced in the receiver coil under the influence of the magnetic field.

Here, the wireless power transmission means may include a wireless charging technology of the electromagnetic induction method defined by the Wireless Power Consortium (WPC) and the Power Matters Alliance (PMA) which is a wireless charging technology standard apparatus.

In addition, the receiver according to an embodiment of the present invention may be provided with at least one wireless power receiving means, and may simultaneously receive wireless power from two or more transmitters. Here, the wireless power receiving means may include an electromagnetic induction wireless charging technology defined by the Wireless Power Consortium (WPC) and the Power Matters Alliance (PMA), which are wireless charging technology standard organizations.

The receiver according to the present invention is a mobile phone, smart phone, laptop computer, digital broadcasting terminal, PDA (Personal Digital Assistants), PMP (Portable Multimedia Player), navigation, MP3 player, electric It may be used in a small electronic device such as a toothbrush, an electronic tag, a lighting device, a remote control, a fishing bobber, a wearable device such as a smart watch, but is not limited thereto. If the device is equipped with a wireless power receiver according to the present invention, the battery can be charged. It is enough.

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

Referring to FIG. 1, a wireless charging system includes a wireless power transmitter 10 that largely transmits power wirelessly, a wireless power receiver 20 that receives the transmitted power, and an electronic device 30 that receives the received power. Can be configured.

For example, the wireless power transmitter 10 and the wireless power receiver 20 may perform in-band communication for exchanging information using the same frequency band as the operating frequency used for wireless power transmission.

In another example, the wireless power transmitter 10 and the wireless power receiver 20 perform out-of-band communication for exchanging information using a separate frequency band different from an operating frequency used for wireless power transmission. It can also be done.

For example, the information exchanged between the wireless power transmitter 10 and the wireless power receiver 20 may include control information as well as status information of each other. Here, the status information and control information exchanged between the transmitting and receiving end will be more clear through the description of the embodiments to be described later.

The in-band communication and the out-of-band communication may provide bidirectional communication, but are not limited thereto. In another embodiment, the in-band communication and the out-of-band communication may provide one-way communication or half-duplex communication.

 For example, the unidirectional communication may be performed by the wireless power receiver 20 only transmitting information to the wireless power transmitter 10, but is not limited thereto. The wireless power transmitter 10 may transmit information to the wireless power receiver 20. It may be to transmit.

In the half-duplex communication method, bidirectional communication between the wireless power receiver 20 and the wireless power transmitter 10 is possible, but at one time, only one device may transmit information.

The wireless power receiver 20 according to an embodiment of the present invention may obtain various state information of the electronic device 30.

For example, the state information of the electronic device 30 may include current power usage information, information for identifying a running application, CPU usage information, battery charge status information, battery output voltage / current information, and the like. The information may be obtained from the electronic device 30 and may be utilized for wireless power control.

In particular, the wireless power transmitter 10 according to an embodiment of the present invention may transmit a predetermined packet indicating whether to support fast charging to the wireless power receiver 20.

The wireless power receiver 20 may notify the electronic device 30 when it is determined that the connected wireless power transmitter 10 supports the fast charging mode.

The electronic device 30 may indicate that fast charging is possible through predetermined display means provided, for example, it may be a liquid crystal display.

In addition, the user of the electronic device 30 may control the wireless power transmitter 10 to operate in the fast charge mode by selecting a predetermined fast charge request button displayed on the liquid crystal display.

In this case, when the quick charge request button is selected by the user, the electronic device 30 may transmit a predetermined quick charge request signal to the wireless power receiver 20.

The wireless power receiver 20 may generate a charging mode packet corresponding to the received fast charge request signal and transmit the generated charging mode packet to the wireless power transmitter 10, thereby converting the general second power charging mode into the fast charging mode.

The wireless power transmitter according to an embodiment of the present invention may include two transmitters. In this case, in the normal charging mode, when charging is performed using one transmitter and then switched to the fast charging mode, charging may be performed using two transmitters. That is, the wireless power transmitter may dynamically control the number of transmitters used for charging according to the charging mode.

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

For example, as illustrated by reference numeral 200a, the wireless power receiver 20 may be configured with a plurality of wireless power receivers, and a plurality of wireless power receivers are connected to one wireless power transmitter 10 so that the wireless Charging may also be performed.

In this case, the wireless power transmitter 10 may distribute and transmit power to the plurality of wireless power receivers in a time division manner, but is not limited thereto. In another example, the wireless power transmitter 10 may be allocated for each wireless power receiver. By using different frequency bands, power may be distributed and transmitted to a plurality of wireless power receivers.

In this case, the number of wireless power receivers that can be connected to one wireless power transmitter 10 may include at least one of required power for each wireless power receiver, a state of charge of a battery, power consumption of an electronic device, and available power of the wireless power transmitter. Can be adaptively determined based on the

As another example, as shown at 200b, the wireless power transmitter 10 may be configured with a plurality of wireless power transmitters.

In this case, the wireless power receiver 20 may be connected to a plurality of wireless power transmitters at the same time, and may simultaneously receive power from the connected wireless power transmitters and perform charging.

In this case, the number of wireless power transmitters connected to the wireless power receiver 20 is adaptively based on the required power of the wireless power receiver 20, the state of charge of the battery, the power consumption of the electronic device, the available power of the wireless power transmitter, and the like. Can be determined.

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

Referring to FIG. 3, the wireless power transmitter 300 may largely include a power converter 310, a power transmitter 320, a communicator 330, a controller 340, and a sensor 350. . It should be noted that the configuration of the wireless power transmitter 300 is not necessarily an essential configuration, and may include more or fewer components.

As shown in FIG. 3, when the DC power is supplied from the power supply unit 360, the power converter 310 may perform a function of converting the power into AC power having a predetermined intensity.

To this end, the power converter 310 may include a DC / DC converter 311, an inverter 312, and a frequency generator 313.

Here, the inverter 312 may be a half bridge inverter or a full bridge inverter, but is not limited thereto. The inverter 312 may be a circuit configuration capable of converting DC power into AC power having a specific operating frequency.

The DC / DC converter 311 may perform a function of converting DC power supplied from the power supply unit 350 into DC power having a specific intensity according to a control signal of the controller 340.

In this case, the sensing unit 350 may measure the voltage / current of the DC-converted power and provide the same to the controller 340.

In addition, the sensing unit 350 may measure the internal temperature of the wireless power transmitter 300 to determine whether overheating occurs, and provide the measurement result to the controller 340.

For example, the controller 340 may adaptively block power supply from the power supply unit 350 or block power from being supplied to the inverter 312 based on the voltage / current value measured by the sensing unit 350. Can be.

To this end, one side of the power converter 310 may further include a predetermined power cut-off circuit for cutting off the power supplied from the power supply unit 350 or cutting off the power supplied to the inverter 312.

The inverter 312 may convert the DC / DC converted DC power into AC power based on a reference AC signal generated by the frequency generator 313, which may be, for example, a pulse width modulated signal. In this case, the frequency of the reference AC signal may be dynamically changed according to the control signal of the controller 340.

The wireless power transmitter 300 according to an embodiment of the present invention may adjust the intensity of the output power by adjusting the operating frequency.

For example, the controller 340 may receive power reception state information and / or power control signal of the wireless power receiver through the communication unit 330, and may be based on the received power reception state information or (and) power control signal. It is possible to adjust the intensity of the power output.

For example, the power reception state information may include, but is not limited to, strength information of the rectifier output voltage and strength information of a current applied to the receiving coil.

The power control signal may include a signal for requesting power increase, a signal for requesting power reduction, and the like.

The power transmitter 320 may include a multiplexer 321 (or multiplexer) and a transmission coil unit 322. Here, the transmitting coil unit 322 may be composed of first to nth transmitting coils.

In addition, the power transmitter 320 may further include a carrier generator (not shown) for generating a specific carrier frequency for power transmission.

In this case, the carrier generator may generate a specific carrier frequency for mixing with the output AC power of the inverter 312 received through the multiplexer 321.

It should be noted that one embodiment of the present invention may have different frequencies of AC power delivered to each transmitting coil.

According to another embodiment of the present invention, the resonance frequency of each transmission coil may be set differently by using a predetermined frequency controller having a function of differently adjusting the LC resonance characteristics for each transmission coil.

The multiplexer 321 may perform a switch function for transferring AC power to a transmission coil selected by the controller 340. The controller 340 may select a transmission coil to be used for power transmission to the corresponding wireless power receiver based on a predetermined signal strength indicator received from the wireless power receiver for each transmission coil.

When a plurality of wireless power receivers are connected, the controller 340 according to an embodiment of the present invention may transmit power through time division multiplexing for each transmission coil.

For example, in the wireless power transmitter 300, three wireless power receivers, i.e., the first to third wireless power receivers, are each identified through three different transmitting coils, i.e., the first to third transmitting coils. In addition, the controller 340 may control the multiplexer 321 to control AC power to be transmitted only through a specific transmission coil in a specific time slot.

In this case, the amount of power transmitted to the corresponding wireless power receiver may be controlled according to the length of the time slot allocated to each transmitting coil, but this is only one embodiment. The power output to the wireless power receiver may be controlled by controlling the intensity of the output DC power of the DC / DC converter 311.

The controller 340 may control the multiplexer 321 to sequentially transmit the detection signals through the first to nth transmission coils 322 during the first detection signal transmission procedure.

In this case, the controller 340 may identify a time point at which the detection signal is transmitted using the timer 355. When the detection signal transmission time arrives, the control unit 340 controls the multiplexer 321 to detect the detection signal through the corresponding transmission coil. Can be controlled to be sent.

For example, the timer 350 may transmit a specific event signal to the controller 340 at a predetermined period during the step of transmitting a detection signal, and the controller 340 may multiplexer 321 whenever the corresponding event signal is detected. ) Can be controlled to transmit a specific detection signal through the corresponding transmission coil.

In addition, the control unit 340 transmits a predetermined transmission coil identifier and a corresponding transmission coil for identifying which transmission coil has received a signal strength indicator from the demodulator 332 during the first detection signal transmission procedure. Signal strength indicator received through the can be received.

Subsequently, in the second detection signal transmission procedure, the control unit 340 controls the multiplexer 321 so that the detection signal may be transmitted only through the transmission coil (s) in which the signal strength indicator has been received during the first detection signal transmission procedure. You may.

As another example, the control unit 340 transmits the second sensed signal to the transmitting coil in which the signal strength indicator having the largest value is received when there are a plurality of transmit coils in which the signal strength indicator is received during the first sensed signal transmitting procedure. In the procedure, the detection signal may be determined as the transmission coil to be transmitted first, and the multiplexer 321 may be controlled according to the determination result.

The communicator 330 may include at least one of a modulator 331 and a demodulator 332.

The modulator 331 may modulate the control signal generated by the controller 340 and transmit the modulated control signal to the multiplexer 321.

Here, the modulation scheme for modulating the control signal is a frequency shift keying (FSK) modulation scheme, a Manchester coding modulation scheme, a PSK (Phase Shift Keying) modulation scheme, a pulse width modulation scheme, a differential 2 Differential bi-phase modulation schemes may be included, but is not limited thereto.

When a specific signal is detected through the transmitting coil, the demodulator 332 may demodulate the detected signal and transmit the demodulated signal to the controller 340.

Here, the demodulated signal may include a signal strength indicator, an error correction (EC) indicator for controlling power during wireless power transmission, an end of charge (EOC) indicator, an overvoltage / overcurrent / overheat indicator, and the like. However, the present invention is not limited thereto, and may include various state information for identifying a state of the wireless power receiver.

In addition, the demodulator 332 may identify from which transmission coil the demodulated signal is received, and may provide the control unit 340 with a predetermined transmission coil identifier corresponding to the identified transmission coil.

 In addition, the demodulator 332 may demodulate a signal received through the transmission coil 323 and transmit the demodulated signal to the controller 340. For example, the demodulated signal may include a signal strength indicator, but is not limited thereto. The demodulated signal may include various state information of the wireless power receiver.

For example, the wireless power transmitter 300 may obtain the signal strength indicator through in-band communication that communicates with the wireless power receiver using the same frequency used for wireless power transmission.

In addition, the wireless power transmitter 300 may not only transmit wireless power using the transmission coil unit 322 but also exchange various control signals and state information with the wireless power receiver through the transmission coil unit 322. .

As another example, a separate coil corresponding to each of the first to nth transmitting coils of the transmitting coil unit 322 may be additionally provided in the wireless power transmitter 300, and wireless power may be provided by using the provided separate coil. Note that in-band communication with the receiver may also be performed.

In the description of FIG. 3, the wireless power transmitter 300 and the wireless power receiver perform in-band communication by way of example. However, this is only one embodiment. Short-range bidirectional communication may be performed through a frequency band different from that of FIG.

For example, the short-range bidirectional communication may be any one of low power Bluetooth communication, RFID communication, UWB communication, and Zigbee communication.

In addition, in the description of FIG. 3, the power transmitter 320 of the wireless power transmitter 300 includes a multiplexer 321 and a plurality of transmission coils 322, but this is only one embodiment. It should be noted that the power transmitter 320 according to the embodiment may be composed of one transmitting coil. In this case, the power transmitter 320 may not be provided with the multiplexer 321.

FIG. 4 is a block diagram illustrating a structure of a wireless power receiver interworking with the wireless power transmitter according to FIG. 3.

Referring to FIG. 4, the wireless power receiver 400 includes a receiving coil 410, a rectifier 420, a DC / DC converter 430, a load 440, a sensing unit 450, and a communication unit ( 460, the main controller 470 may be configured. Here, the communicator 460 may include at least one of a demodulator 461 and a modulator 462.

Although the wireless power receiver 400 illustrated in the example of FIG. 4 is illustrated as being capable of exchanging information with the wireless power transmitter 300 through in-band communication, this is only one embodiment. The communication unit 460 according to another embodiment may provide short-range bidirectional communication through a frequency band different from the frequency band used for wireless power signal transmission.

AC power received through the receiving coil 410 may be delivered to the rectifier 420. The rectifier 420 may convert AC power into DC power and transmit the DC power to the DC / DC converter 430. The DC / DC converter 430 may convert the strength of the rectifier output DC power into a specific strength required by the load 440 and then transfer the power to the load 440.

The sensing unit 450 may measure the intensity of the output DC power of the rectifier 420 and provide it to the main controller 470.

In addition, the sensing unit 450 may measure the strength of the current applied to the receiving coil 410 according to the wireless power reception, and may transmit the measurement result to the main controller 470.

In addition, the sensing unit 450 may measure the internal temperature of the wireless power receiver 400 and provide the measured temperature value to the main controller 470.

For example, the main controller 470 may determine whether the overvoltage occurs by comparing the measured intensity of the rectifier output DC power with a predetermined reference value.

As a result of the determination, when the overvoltage is generated, a predetermined packet indicating that the overvoltage has occurred may be generated and transmitted to the modulator 462.

Here, the signal modulated by the modulator 462 may be transmitted to the wireless power transmitter 300 through the receiving coil 410 or a separate coil (not shown).

In addition, the main controller 470 may determine that the detection signal is received when the intensity of the rectifier output DC power is greater than or equal to a predetermined reference value. When the detection signal is received, a signal strength indicator corresponding to the detection signal may be modulated by the modulator 462. ) To be transmitted to the wireless power transmitter 300.

As another example, the demodulator 761 demodulates an AC power signal or a rectifier 420 output DC power signal between the receiving coil 410 and the rectifier 420 to identify whether a sensing signal is received, and then, the demodulation unit 761 may control the identification result. It may be provided to the unit 470.

In this case, the main controller 470 may control the signal strength indicator corresponding to the detection signal to be transmitted through the modulator 462.

5A is a block diagram illustrating an internal structure of a wireless power transmitter having a switched mode power supply according to an embodiment of the present invention.

Referring to FIG. 5A, the wireless power transmitter 500 may include a main controller 510, a gate driver 520, an inverter 530, a power transmitter 540, an AC power source 550, and variable frequency switching mode power. It may include a supply (Variable Frequency Switching Mode Power Supply (VF SMPS), 560) and the communication demodulator 570.

The AC voltage signal V_in supplied from the AC power source 550 may be converted into the DC voltage signal V_rail by the VF SMPS 560 and then supplied to the inverter 530.

In general, a switching mode power supply (SMPS) uses a switch control scheme that converts AC power into DC power using a switching transistor, a filter, a rectifier, and the like as a power supply. Here, the rectifier and the filter may be configured independently and disposed between the AC power source and the SMPS.

SMPS is a power supply that controls the on / off time ratio of semiconductor switch element and supplies the stabilized output DC power to the device or circuit element. It is widely used in equipment and equipment.

In many cases, the stability and precision of electronic circuit operation depends on the quality of the power supply. In general, there are two methods of converting a stable power supply from a battery and a commercial AC power supply, a series regulator method and a switched mode method.

Linear control schemes used in TV receivers, CRT monitors, and the like have simple peripheral circuits and are inexpensive, but have disadvantages such as high heat generation, low power efficiency, and large volume.

On the other hand, the switching mode method has the advantages of almost no heat generation, high power efficiency, and small volume. However, the switching mode method is expensive, complicated circuit, and output noise and electromagnetic interference due to high frequency switching.

A variable variable switching mode power supply (SMPS) applied to a wireless charging system generates a DC voltage by switching and rectifying AC voltages of several tens of Hz bands output from an AC power supply.

A variable SMPS may output a DC voltage of a constant level or adjust the output level of the DC voltage according to a predetermined control of a Tx controller.

The variable SMPS controls the supply voltage according to the output power level of the power amplifier, i.e., the inverter 530, so that the power amplifier of the wireless power transmitter can always operate in the highly efficient saturation region, thus providing maximum efficiency at all output levels. Can be maintained.

If a commercially available SMPS is used instead of the variable SMPS, a variable DC / DC converter may be additionally used.

Commercial SMPSs and variable DC / DC converters can control the supply voltage according to the power amplifier's output power level, allowing the power amplifier to operate in a highly efficient saturation region, ensuring maximum efficiency at all output levels.

In one embodiment, the power amplifier may be a Class E type, but is not limited thereto.

The inverter 530 converts the DC voltage V_rail of a constant level to a AC voltage by a switching pulse signal of a few MHz to several tens of MHz bands, that is, a pulse width modulated signal, received through the gate driver 520. The AC power to be transmitted wirelessly can be generated by converting to.

In this case, the gate driver 520 may generate a plurality of PWM signals for controlling the plurality of switches included in the inverter 530 using the reference clock signal Ref_CLK supplied from the main controller 510.

In the embodiment of FIG. 5A, four PWM signals SC1, SC2, SC3, and SC4 for controlling each of the four switches provided with the inverter 530 are illustrated as receiving from the gate driver 520. However, this is only one embodiment, and when the inverter is configured as a half bridge according to another embodiment, two PWM signals for controlling each of the two switches may be received from the gate driver 520. .

Here, the switch may be formed of a MOSFET (MOSFET, Metal Oxide Semiconductor Field Effect transistor), but this is only one embodiment, other types of switches may be used.

The VF SMPS 560 may dynamically adjust the DC voltage V_rail output according to the control signal of the main controller 510.

For example, the main controller 510 may dynamically control the output DC voltage of the VF SMPS 560 according to the strength of power required by the receiver to be charged.

As another example, when the main controller 510 detects an overvoltage, an overcurrent, an overheat, etc. by a sensor provided, the main controller 510 dynamically cuts off the AC power source 550 or reduces the output DC voltage V_rail of the VF SMPS 560. Or blocked.

In addition, the VF SMPS 560 and the variable DC / DC converter may have different efficiency characteristics for the input current depending on the manufacturer and the application thereof.

For example, the variable DC / DC converter of the first manufacturer may have an efficiency of 85% when the input current is 1A, and an efficiency of 95% when the current is 2A. On the other hand, the variable DC / DC converter of the second manufacturer has an efficiency of 95% when the input current is 1A, and an efficiency of 85% when the current is 2A.

The main controller 510 may control the overall operation of the wireless power transmitter 500.

The power transmitter 540 includes at least one power transmission antenna (not shown)-for example, an LC resonant circuit-and a matching circuit for impedance matching, for wirelessly transmitting an AC power signal output from the inverter 530. It may be configured to include).

In addition, when the power transmitter 540 is provided with a plurality of transmission coils, the power transmitter 540 may further include a selection switching circuit for selecting a transmission coil to be used for wireless power transmission among the plurality of transmission coils.

In addition, the power transmitter 540 may further include various sensing circuits for measuring the strength of the power input from the inverter 530 or the strength, temperature, etc. of the power transmitted through the transmission coil. Here, the sensing result may be transmitted to the main controller 510.

The communication demodulator 570 may demodulate and transmit the control signal received through the power transmitter 540 to the main controller 510.

The power transmitter 540 may provide a control signal received through in-band communication to the communication demodulator 570.

5B is a block diagram illustrating an internal structure of a wireless power transmission apparatus equipped with a DC / DC converter according to another embodiment of the present invention.

Referring to FIG. 5B, the wireless power transmitter 501 according to the present embodiment may convert DC power applied from the DC power source 580 into DC power having a specific intensity according to a control signal of the main controller 510. It may also be configured to include a DC converter 590.

For example, the main controller 510 may adjust the DC conversion ratio of the DC / DC converter 590 by adjusting the duty rate of the PWM signal.

For example, when the duty rate is 0.5, the ratio of the output voltage to the input voltage may be 50%.

As another example, when the duty rate is 0.2, the ratio of the output voltage to the input voltage may be 20%.

Description of the remaining components constituting the wireless power transmission apparatus 600 will be replaced with the description of FIG. 5A described above.

6 is a state transition diagram for explaining a wireless power transmission procedure in a wireless power transmission apparatus according to an embodiment of the present invention.

Referring to FIG. 6, the wireless power transmission procedure for wireless charging may be divided into a selection phase (610), a ping phase (620), an identification and configuration phase (630), and a negotiation phase ( Negotiation phase 640, a calibration phase 650, a power transfer phase 660, and a renegotiation phase 670.

When the transmitter detects a specific error or a specific event at any one of the steps included in the wireless power transmission procedure except for the selection step 610, the transmitter may return to the selection step 610.

Here, specific errors and specific events will be apparent from the following description.

In addition, in the selection step 610, the transmitter may monitor the presence of an object on the interface surface, such as a charging area or a charging bed.

If the transmitter detects that an object has been placed on an interface surface, eg, a charging bed, it may transition to ping step 620.

In the selection step 610, the transmitter transmits a very short pulse of an analog ping signal and an object in the active area of the interface surface based on the current change of the transmitting coil or the primary coil. Can detect the presence of

In ping step 620, when an object is detected, the transmitter activates the receiver and sends a digital ping to identify whether the receiver is a receiver that is compatible with a particular standard, such as a WPC standard.

If in ping step 620 the transmitter does not receive a response signal (eg, a signal strength packet) to the digital ping from the receiver, it may transition back to selection step 610.

In addition, in the ping step 620, when the transmitter receives a signal indicating that power transmission is completed, that is, a charging completion packet, the transmitter may transition to the selection step 610.

Once the ping step 620 is complete, the transmitter may transition to the identification and configuration step 630 to identify the receiver and collect receiver configuration and status information.

In the identification and configuration step 630, the transmitter receives an unexpected packet, an outgoing desired packet for a predefined time, a packet transmission error, or a power transmission agreement. If this is not set (no power transfer contract) it may transition to selection step 610.

The transmitter may determine whether entry into the negotiation step 640 is necessary based on a negotiation field value of the configuration packet received in the identification and configuration step 630.

As a result of the check, if negotiation is necessary, the transmitter may enter a negotiation step 640 to perform a predetermined FOD detection procedure.

On the other hand, if no verification is required as a result of the check, the transmitter may immediately enter the power transmission step 660.

In the negotiation step 640, the transmitter may receive a Foreign Object Detection (FOD) status packet including a reference quality factor value.

In this case, the transmitter may determine a threshold for FO detection based on the reference quality factor value.

The transmitter may detect whether the FO exists in the charging region by using the determined threshold for FO detection and the currently measured quality factor value, and control power transmission according to the FO detection result.

For example, when the FO is detected, power transmission may be stopped, but is not limited thereto.

If the FO is detected, the transmitter may return to selection step 510. On the other hand, when no FO is detected, the transmitter may enter the power transfer step 660 via the correction step 550.

In detail, when the FO is not detected, the transmitter determines the strength of the power received at the receiving end in the correction step 650, and calculates the power loss at the receiving end and the transmitting end to determine the strength of the power transmitted at the transmitting end. It can be measured.

The transmitter may predict power loss based on the difference between the transmit power of the transmit end and the receive power of the receive end in the correction step 650. The transmitter according to an embodiment may correct the threshold for FOD detection by reflecting the predicted power loss.

In the power transfer step 640, the transmitter receives an unexpected packet, an outgoing desired packet for a predefined time, or a violation of a preset power transfer contract. transfer contract violation), if filling is complete, then transition to optional step 610.

Further, in power transfer step 660, the transmitter may transition to renegotiation step 670 if it is necessary to reconfigure the power transfer agreement in accordance with a change in transmitter state or the like. At this time, if the renegotiation is normally completed, the transmitter may return to the power transmission step (660).

The power transmission contract may be set based on state and characteristic information of the transmitter and the receiver.

For example, the transmitter status information may include information on the maximum transmittable power, information on the available power, information on the maximum number of receivers, etc. The receiver status information may include information on the required power, etc. have.

Here, the receiver may determine the required power based on the information on the available power of the transmitter and the power currently being received.

7 is a view for explaining the structure of a high power wireless power transmission apparatus according to an embodiment of the present invention.

Referring to FIG. 7, an apparatus 700 for transmitting power wirelessly includes an AC power source 701, a noise filter 702, a rectifier 703, an inverter input voltage controller 704, and a switch. 705, Transformer 706, Main Controller 707, Gate Driver 708, Inverter 709, Coil Unit 710, Power Sensor 711 , A receiver detector (712), an analog to digital converter (ADC: Analog Digital Converter, 713) and may include at least one of the diode 718.

The noise filter 702 may include an EMI filter circuit for eliminating electromagnetic interference (EMI) included in the AC power supply 701 and / or a surge protector element for catching a surge voltage of several Kv. It may be configured to include.

The rectifier 703 may convert an AC power supply passing through the noise filter 703 into a direct current.

The inverter input voltage controller 704 may receive operating power from the converter 706 and control the switch 705 ON / OFF according to a predetermined control signal of the main controller 707.

As an example, the main controller 707 has a second inverter input voltage, i.e., V_RAIL # 2-, in the inverter 709 in a standby state, including, for example, a selection step 610 and a ping step 620. It can be controlled to be applied.

In detail, when the main controller 707 enters the standby state, the main controller 707 may transmit a predetermined control signal to the inverter input voltage controller 704 to control the switch 705 to be open (OFF). When the switch 705 is OFF, the second inverter input voltage may be input to the inverter 709.

As another example, when the main controller 707 detects that a receiver, for example, a receiver capable of receiving power of 60 W, is disposed in the charging area in the standby state, the main controller 707 may control the inverter input voltage controller 704. By transmitting a signal, the switch 705 can be controlled to be shorted (ON).

In this case, a first inverter input voltage, that is, V_RAIL # 1- may be applied to the inverter.

As another example, the main controller 707 may control the switch 705 to remain open (OFF) when it detects that the foreign matter is disposed in the charging area in the standby state.

As another example, when the main controller 707 detects that the receiver is removed from the charging region while the main controller 707 is charging the receiver, that is, the first inverter input voltage is supplied to the inverter 702, the inverter input voltage The switch 705 may be controlled to be open (OFF) by transmitting a predetermined control signal to the controller 704.

When the switch 705 is OFF, the voltage applied to the inverter 709 may be changed from the first inverter input voltage to the second inverter input voltage.

According to another embodiment of the present disclosure, the main controller 707 may identify the type of the receiver disposed in the charging area.

For example, the type of receiver may be divided into a first receiver of 5-15W class and a second receiver of 60W class, but this is only one embodiment, and more receiver types are defined according to more granular power classes. Care should be taken.

For example, when the receiver sensed in the standby state is the first receiver, the main controller 707 may control the switch 705 to maintain the open state.

That is, the main controller 707 may control the second inverter input voltage to be supplied to the inverter 709 when the first receiver is detected.

As another example, when the receiver sensed in the standby state is the second receiver, the main controller 707 may switch the switch 705 from the open (OFF) state to the short state (ON) state. .

That is, the main controller 707 may control the first inverter input voltage to be supplied to the inverter 709 when the second receiver is detected.

For example, the first inverter input voltage is 330V, the second inverter input voltage may be a voltage of 12V, but is not limited thereto, and if the first inverter input voltage is several times or tens of times higher than the second inverter input voltage. It is enough.

The inverter input voltage controller 704 controls the switch 705 according to the control signal of the main controller 707 so that the first inverter input voltage V_RAIL # 1, which is a DC voltage rectified by the rectifier 703, is switched by the switch 705. ) May be controlled to be supplied to the inverter 709, or may be controlled so that the second inverter input voltage V_RAIL # 2, which is a voltage dropped by the converter 706, may be supplied to the inverter 709. .

In the present invention, the inverter input voltage may be defined as a DC voltage applied to the inverter 709.

If the inverter input voltage controller 740 turns the switch 705 on, V4 716-that is, V_RAIL # 2- is cut off by the diode 718, and only V_RAIL # 1 can be supplied to the inverter 703. Can be.

On the other hand, when the inverter input voltage controller 740 turns off the switch 705, V4 716-that is, V_RAIL # 2- is supplied to the inverter 703 through the diode 718, and V_RAIL # 1 is connected to the switch ( 705 may be blocked.

For convenience of description below, the DC voltage V_RAIL # 1 transmitted to the inverter 709 through the switch 705 is mixed with the first V_RAIL or the first inverter input voltage, and the converter 706 and the diode ( The inverter input voltage V_RAIL # 2 transmitted to the inverter 709 through 718 is mixed with the second V_RAIL or the second inverter input voltage.

Rectifier output voltage V1 714-hereafter, for convenience of explanation, to use V1 714 in combination with the first voltage-when applied to converter 706, converter 706 is applied to the first voltage ( The voltage drop 714 may be performed to generate second voltages V2 and 714, fifth voltages V5 and 717, and sixth voltages V6 and 718.

Here, the fifth voltage 717 and the sixth voltage 718 may be used as driving voltages of the gate driver 708 and the inverter input voltage controller 707, respectively. For example, the fifth voltage 717 may be 12V, but is not limited thereto.

The converter 706 may convert the first voltage 714 into the second voltage 714. In this case, the converted second voltage 714 may be divided into a third voltage 715 and a fourth voltage 716 and applied to the main controller 707 and the diode 718, respectively.

If the switch 705 is ON, the first V_RAIL, which is a relatively high voltage, is supplied to the inverter 709, so that the second V_RAIL, that is, the fourth voltage 716, is a voltage that is low enough to be ignored. Can be.

On the other hand, when the switch 705 is turned OFF, the first V_RAIL is blocked from being supplied to the inverter 709, and the second inverter input voltage, ie, the fourth voltage 716, is passed through the diode 718 to the inverter 709. ) Can be supplied.

Here, it should be noted that the second voltage 714 is lower than the first voltage 714.

For example, the first voltage 714 may be DC 310V, and the second voltage 714 may be DC 5V. However, this is only one embodiment, and the voltage of the first voltage 714 and the converter 706 may be different. The rate of descent may be different depending on the design of those skilled in the art.

If the second voltage 714 is DC 5V, the third voltage 715 may be DC 3.3V, and the second voltage 716 may be DC 2.5V. However, the main controller 707 and the diode 718 may be used. The voltage applied to may be distributed differently according to the design of those skilled in the art.

As described above, the inverter input voltage controller 704 may control the switch 705 so that any one of the first inverter input voltage and the second inverter input voltage is supplied to the inverter 709.

The diode 718 may block the first inverter input voltage V_RAIL # 1, which is a relatively high voltage, from being applied to the main control path 707 or the converter 706 when the switch 705 is turned on.

The main controller 707 may control the operation of the inverter input voltage controller 703 based on the output signal of the receiver detector 714.

As an example, the receiver detector 712 is a voltage V_CL, hereinafter referred to as a coil voltage, an inverter input voltage V_RAIL, and a specific reference voltage V_RF, for example, a reference voltage applied to the coil unit 710. Based on the second voltage V2 may be used to generate a predetermined control signal for identifying whether the receiver is normally disposed in the charging region, whether foreign matter is disposed, and whether the receiver disposed in the charging region is removed. can do.

Here, the generated control signal is transmitted to the main controller 707, and may dynamically control the inverter input voltage controller 704 based on the control signal received from the main controller 707 and the receiver detector 712.

For example, if it is determined that the receiver is not disposed in the charging region or the foreign material is disposed, the main controller 707 may turn off the switch 705 by controlling the inverter input voltage controller 707.

In this case, a ping signal or a wireless power signal of a relatively low voltage is transmitted through the coil unit 710, so that standby power consumption of the wireless power transmission apparatus 700 can be minimized as well as damage of the device disposed in the charging region. Can be minimized.

On the other hand, if the main controller 707 determines that the receiver is disposed in the charging region, the switch 705 may be turned on by controlling the inverter input voltage controller 707.

In this case, the first inverter input voltage, which is a relatively high voltage, may be supplied to the interceptor 709 to perform normal charging of the corresponding receiver. As an example, the receiver may be a high power receiver having a power rating of 60W.

If the inverter input voltage is kept low even though the receiver is normally disposed in the charging region, normal charging of the receiver may not be possible. In addition, when a high current flows in the coil unit 710 as the required power of the receiver increases, the wireless power transmitter 700 may generate severe heat generation and a lot of power loss.

Therefore, the wireless power transmission apparatus 700 according to an embodiment of the present invention, when the wireless charging is started after the receiver sensing-that is, when entering the power transmission step 660, high voltage and low current corresponding to the required power of the receiver By transmitting the wireless power signal through the coil unit 710, there is an advantage that can be controlled to achieve low heat generation and high efficiency charging.

The power sensor 711 may measure the V rail voltage V_RAIL and the V rail current I_RAIL supplied to the inverter 709 and provide the same to the main controller 707.

The ADC 713 may measure the coil current I_CL and the coil voltage V_CL applied to the coil unit 710, and digitally convert the coil current I_CL to the main controller 707.

In addition, the ADC 713 may convert the voltage measurement value I_SENCE and the current measurement value V_SENCE for demodulating the analog feedback signal of the wireless power receiver into a digital signal and provide the same to the main controller 707.

Detailed configuration and operation of the receiver detector 712 and the main control channel 707 will be described in more detail with reference to FIGS. 8 to 10 to be described later.

Through the above configuration, the wireless power transmission apparatus 700 according to the present invention may identify the receiver disposed in the charging region by using the receiver detector 712 provided when entering the ping phase.

In addition, the wireless power transmission apparatus 700 according to the present invention may enter the identification and configuration step 630 to identify the type of the receiver disposed in the charging area.

In this case, the wireless power transmission apparatus 700 may adaptively control the inverter input voltage according to the identified receiver type, thereby preventing damage of the low power receiver in advance and maximizing charging efficiency for the high power receiver. There are advantages to it.

In addition, the wireless power transmission apparatus 700 according to the present invention identifies the type of the wireless power receiver based on the output of the receiver detector 712 even before entering the identification and configuration step for identifying the type of the wireless power receiver. There is an advantage to this.

In addition, the wireless power transmission apparatus 700 according to the present invention has an advantage of identifying the type of the receiver based on the output of the receiver detector 712 even before establishing communication with the wireless power receiver.

8 is a block diagram illustrating a configuration and a connection relationship between a main controller and a receiver detector of a wireless power transmitter according to an embodiment of the present invention.

Referring to FIG. 8, the main controller 707 may include a first port 801 and a second port 802.

The receiver detector 712 includes a first comparator 811, a second comparator 812, a first filter 813, a second filter 814, a third filter 815, a first buffer 816, a second A buffer 817, a first voltage control circuit 818, and a second voltage control circuit 819 may be included.

The V-rail V_RAIL, which is an inverter input voltage, passes through the first voltage control circuit 818, the first buffer 816, and the first filter 813 to be input to the first input terminal of the first comparator 811. Can be.

The coil voltage V_CL may be input to the second input terminal of the first comparator 811 after passing through the second voltage control circuit 819, the second buffer 817, and the second filter 814.

In addition, the coil voltage V_CL may be input to the first input terminal of the second comparator 812 after passing through the second voltage control circuit 819, the second buffer 817, and the second filter 814. .

The reference voltage V2 may be input to the second input terminal of the second comparator 812 through the third filter 815.

The first to third filters 813 according to the present embodiment may have different internal circuit configurations, but may operate as a voltage filter for dropping an input voltage.

In the first voltage control circuit 818 and the second voltage control circuit 819 according to the present embodiment, the drop levels of the inverter input voltage V_RAIL and the coil voltage V_CL are controlled according to the control signal of the main controller 707. Circuit elements configured to be included may be included.

At this time, the control signal of the main controller 707 applied to the first voltage control circuit 818 and the second voltage control circuit 819 is controlled by the inverter input voltage controller 704 in FIG. The signal may be the same as or correspond to the switch control signal used to.

For example, referring to FIG. 7, when the inverter input voltage controller 707 outputs a control signal (hereinafter, referred to as a switch short control signal) to short-circuit the switch 705, the receiver detector 712. The switch short control signal may also be applied.

As another example, referring to FIG. 7, when the inverter input voltage controller 707 outputs a control signal (hereinafter, referred to as a switch open control signal) to open the switch 705, the receiver detector 712. ) May also be applied to the switch open control signal.

The first voltage control circuit 818 and the second voltage control circuit 819 may include a plurality of resistors and switches for controlling the voltage drop level.

Further, the second voltage control circuit 819 rectifies the coil voltage V_CL, which is an alternating voltage, and converts the rectified element into a direct current voltage, for example, the rectifying element includes a diode and a ripple component of the rectified signal. And may further comprise a smoothing element for removal, for example, the smoothing element includes a capacitor.

Detailed circuit configuration and operation of the first voltage control circuit 818 and the second voltage control circuit 819 will be more clearly understood through the description of FIGS. 12 to 13 to be described later.

Here, the main controller 707 dynamically lowers the voltage drop level of the first voltage control circuit 818 and the second voltage control circuit 819 based on whether the receiver is detected, the foreign matter is detected, or the receiver is being removed. Can be controlled.

The first voltage control circuit 818 and the second voltage control circuit 819 respectively break the first buffer 816 and the second buffer 817 from the high voltage inverter input voltage V_RAIL and the coil voltage V_CL. You can also perform a function to prevent.

For example, in response to the detection of the receiver, the output voltage of the first voltage control circuit 818 at the time when V_RAIL is provided to the first inverter input voltage, for example, DC 330V-, the first output voltage and the high power receiver. Non-generic receiver—for example, may be a receiver capable of receiving 5 to 15W of power—or a first time at which V_RAIL is provided to a second inverter input voltage—for example, DC 2.5V—by detecting a foreign object or the like. The output voltage of the voltage control circuit 818, hereinafter, the second output voltage, may have different levels.

Here, the first output voltage may be lower than the second output voltage. In addition, the main controller 707 may control the second output voltage to be output by the first voltage control circuit 818 even in the ping mode or the standby state for transmitting the ping signal.

The output of the first comparator 811 may be connected to the first port 801 of the main controller 801, and the output of the second comparator 812 may be connected to the second port 802 of the main controller 801. .

The first to third filters 813, 814, and 815 may be configured as a low pass filter configured by a resistor and a capacitor to pass a low frequency signal and block a high frequency signal.

The first buffer and the second buffer 816 and 817 may provide electrical buffering between circuits having different electrical characteristics.

For example, it may be configured as an operational amplifier (op-amp) having a feedback gain of approximately 1, also called a voltage follower or simply a buffer.

The main controller 707 may detect a receiver disposed in the charging area based on the level of the signal detected by the first port 801 and the second port 802.

9 is a circuit diagram illustrating a detailed configuration of a main controller and a receiver detector of a wireless power transmission apparatus according to an embodiment of the present invention.

Referring to FIG. 9, the main controller 707 may include a first port 801 for determining the first comparator output COMP # 1 and a second port 802 for determining the second comparator output COMP # 1. It may be configured to include).

The receiver detector 712 includes a first comparator 811, a second comparator 812, a first filter 813, a second filter 814, a third filter 815, a first buffer 816, a second A buffer 817, a first voltage control circuit 818, and a second voltage control circuit 819 may be included.

The inverter input voltage may be input to the first input terminal (+) of the first comparator 811 after passing through the first voltage control circuit 818, the first buffer 816, and the first filter 813.

Here, the first input terminal (-) of the first buffer 816 is connected to the output terminal of the first buffer 816 to form a feedback loop, and the second input terminal (+) is connected through the first resistor element 901. It can be connected to the inverter input voltage.

In addition, a second resistance element 902 may be disposed between the output of the first buffer 816 and the first filter 813 to drop the output voltage of the first buffer 816.

Between the first comparator 811 and the first port 801, a third resistor element 903 to a fourth resistor element 904 are disposed in parallel to distribute the output voltage of the first comparator 811, and the second comparator. Sixth and seventh resistor elements 906 to 907 may be disposed in parallel between 812 and the second port 802 to distribute the output voltage of the second comparator 812.

The coil voltage V_CL may be input to the second input terminal (-) of the first comparator 811 after passing through the second voltage control circuit 819, the second buffer 817, and the second filter 814. have.

In addition, the coil voltage V_CL is input to the first input terminal (-) of the second comparator 812 after passing through the second voltage drop circuit 819, the second buffer 817, and the second filter 814. Can be.

The voltage drop level of the inverter input voltage V_RAIL may be achieved through switch control included in the first voltage control circuit 818.

The voltage drop level of the coil voltage V_CL may be achieved through a switch control included in the second voltage control circuit 819. The drop level may be controlled.

The reference voltage V_RF may be input to the second input terminal (+) of the second comparator 812 through the third filter 815. Here, the reference voltage RF may be applied to the third filter 815 through the eighth resistor element 908.

Referring to FIG. 9, an output of the first comparator 811 is connected to a first port 801 of the main controller 801, and an output of the second comparator 812 is connected to a second port (of the main controller 801). 802.

The first to third filters 813, 814, and 815 may be configured as a low pass filter configured by a resistor and a capacitor to pass a low frequency signal and block a high frequency signal.

The first buffer and the second buffer 816 and 817 may provide electrical buffering between circuits having different electrical characteristics.

For example, it may be configured as an operational amplifier (op-amp) having a feedback gain of approximately 1, also called a voltage follower or simply a buffer.

The main controller 707 may detect a receiver disposed in the charging area based on the level of the signal detected by the first port 801 and the second port 802.

As illustrated in FIG. 10 to be described later, the main controller 707 is based on the output voltage level COMP # 1 of the first port 801 and the output voltage level COMPP2 of the second port 802. The main controller 707 may not only identify whether the receiver is disposed in the charging region or the foreign substance, but also identify whether the receiver being charged is removed from the charging region.

When the receiver is detected in the ping mode, the main controller 707 turns on the switch 705 to control to operate in a high voltage / low current charging mode, that is, a first inverter input voltage is supplied to the inverter 709. Can be.

If in the charging state, i.e., in the power transfer step 660, it is confirmed that the receiver has been removed from the charging area, the main controller 707 turns off the switch 705 to turn off the low voltage / low current charge mode, i.e. 2 may be controlled to operate with an inverter input voltage supplied to inverter 709.

That is, when the receiver is removed from the charging region during the high voltage / low current charging, the main controller 707 may turn off the switch 705 to switch to the ping mode.

10 is an experimental result table showing a receiver detection result according to a comparator output voltage of a receiver detector according to an embodiment of the present invention.

Referring to reference numeral 1010 of FIG. 10, the inverter input voltage is the second inverter input voltage (V_RAIL # 2), that is, in the voltage-ing mode in which the switch 705 is supplied to the inverter 709 in the OFF state. When the receiver is not disposed in the charging region, the output COMPP1 of the first comparator 811 may be HIGH, and the output COMPP # 2 of the second comparator 812 may be LOW.

On the other hand, in a ping mode state in which the inverter input voltage is the second inverter input voltage V_RAIL # 2, when the receiver is normally disposed in the charging region, the output COMPP1 of the first comparator 811 and the second comparator ( 812) The output COMP # 2 may be stably HIGH as shown in FIG. 1011.

Specifically, referring to reference numeral 1011, when the receiver is disposed vertically spaced within 7 mm from the charging bed, the first comparator 811 output COMPP1 and the second comparator 812 output COMPP2. All have a stable HIGH value.

On the other hand, referring to reference numeral 1012, when the receiver is disposed vertically spaced apart within 10 mm from the charging bed, only the second comparator 812 output COMP # 2 is stably HIGH.

However, referring to reference numeral 1013, when the receiver is arranged to be spaced apart by more than 10 mm vertically from the charging bed, the first comparator 811 output COMP # 1 has a LOW value and the second comparator 812 output. (COMP # 2) shows an unstable value.

When the main controller 707 detects the receiver, the main controller 707 may control the first inverter input voltage to be supplied to the inverter 709 to perform high voltage / low current charging.

At this time, when the receiver under high voltage / low current charging is removed from the charging region, as illustrated in FIG. 1020, the output COMP1 of the first comparator 811 and the output COMP2 of the second comparator 812 are not shown. ) Can all have a LOW value.

When the output (COMP # 2) of the first comparator 811 and the output (COMP # 2) of the second comparator 811 are both turned LOW during the high voltage / low current charging, the main controller 707 is charged. It can be determined that it has been removed from the region, and can switch to the ping mode.

When the main controller 707 stops charging and switches to the ping mode, the main controller 707 may control the second inverter input voltage to be supplied to the inverter 709 to transmit a low voltage / low current ping signal.

FIG. 11 is an experimental result table showing a sensing result according to a comparator output voltage of a receiver detector according to another exemplary embodiment.

As shown in reference numeral 1100 of FIG. 11, the output (COMP # 1) of the first comparator 811 and the second comparator 812 in the ping mode in which the second inverter input voltage is being supplied to the inverter 709. If the output COMPP1 is all LOW, the main controller 707 may determine that the foreign matter is disposed in the charging region.

In this case, the main controller 707 suspends the power transmission and generates a predetermined warning message indicating that a foreign object is detected through a predetermined alarm means (including, for example, a beeper, vibration means, a display, a speaker, and the like). You can print

In addition, the main controller 707 may detect a foreign substance during power transmission. In this case, the main controller 707 reduces or stops the intensity of the output power, and informs that a foreign object has been detected through a predetermined alarm means, including, for example, a beeper, a vibration means, a display, a speaker, and the like. You can also output a warning message.

12A to 12B are diagrams for describing a detailed configuration of the first voltage control circuit disclosed in FIGS. 8 to 9 according to one embodiment of the present invention.

The first voltage control circuit 818 according to an embodiment of the present invention may include first to fifth resistors 1201, 1202, 1203, 1204, and 1205 and a first voltage distribution switch 1210.

Referring to FIG. 12A, the first to third resistors 1201, 1202, and 1203 are disposed in series between the inverter input voltage V_RAIL and the first voltage distribution switch 1210, and the fourth resistor 1204 and the fourth resistor 1203 are disposed in series. The five resistors 1205 may be connected to a switch control signal and an operating voltage, respectively. A voltage between the second resistor 1202 and the third resistor 1203 may be connected to an input terminal of the first buffer 816.

In particular, the switch control signal may be a signal that is identical to or corresponding to a control signal for controlling the switch 705 of FIG. 7.

For example, when the switch 705 of FIG. 7 is turned off, the second inverter input voltage is supplied to the first voltage control circuit 818, and the switch control signal corresponding to the OFF signal is applied to the fourth resistor 1204. Can be.

In this case, the first voltage distribution switch 1210 may be turned off. For example, the second inverter input voltage may be 2.5V, but is not limited thereto, and a specific voltage selected from a voltage of 5V or less may be applied.

When the first voltage distribution switch 1210 is turned off, the current of the first voltage control circuit 818 passes through the first buffer 816 through the first to second resistors 1201 and 1202 as shown in FIG. 1220. Is entered.

That is, when the first voltage divider switch 1210 is turned off, the second inverter input voltage is input to the first buffer 816 after the voltage drops by the first to second resistors 1201 and 1202.

7 and 12B, when the switch 705 of FIG. 7 is turned on, the first inverter input voltage is supplied to the first voltage control circuit 818, and the switch control signal corresponding to the ON signal is provided. 4 may be applied to the resistor 1204. In this case, the first voltage distribution switch 1210 may be turned on. For example, the first inverter input voltage may be 330V, but is not limited thereto. A specific voltage selected from a voltage of 300V or more may be applied.

When the first voltage divider switch 1210 is turned on, the current of the first voltage control circuit 818 may be partially transferred to the first buffer through the first to second resistors 1201 and 1202 as shown in reference numeral 1230. 816, the remainder may flow into ground through third resistor 1203 and first voltage divider switch 1210.

That is, when the first voltage division switch 1210 is turned on, the first inverter input voltage is voltage-divided by the third resistor 1203 as well as the first to second resistors 1201 and 1202, and the second resistor 1202. ) And the third resistor 1203 are input to the first buffer 816.

13A to 13B are diagrams for describing a detailed configuration of the second voltage control circuit disclosed in FIGS. 8 to 9 according to one embodiment of the present invention.

The second voltage control circuit 819 according to the embodiment of the present invention may include the sixth to eleventh resistors 1301, 1302, 1303, 1304, 1305, and 1306, the diode 1307, and the first to second capacitors 1308. 1309 and the second voltage distribution switch 1310.

Referring to FIG. 13A, the coil voltage V_CL applied to the second voltage control circuit 819 may be rectified by the diode 1307 after the voltage drops by the sixth resistor 1301.

The current passing through the diode 1307 passes through the seventh resistor 1302, and a part of the current flows to the ground through the eighth resistor 1303, and the others flow toward the second buffer 817.

The ninth resistor 1304 and the tenth resistor 1305 may be connected to a switch control signal and an operating voltage, respectively.

Here, the switch control signal may be a signal that is the same as or corresponding to the control signal for controlling the switch 705 of FIG. 7.

For example, referring to FIG. 13A, when the switch 705 of FIG. 7 is turned off, a switch control signal corresponding to the OFF signal may be applied to the ninth resistor 1304. In this case, the second voltage distribution switch 1310 may be turned off.

When the second voltage distribution switch 1310 is OFF, the current flow in the second voltage control circuit 819 may be as shown at 1320.

The first to second capacitors 1308 and 1309 may operate as smoothing elements and ripple cancellation elements for converting the half-wave rectified signal into a DC signal of a constant level.

As another example, as shown in FIG. 13B, when the switch 705 of FIG. 7 is turned on, a switch control signal corresponding to the ON signal may be applied to the ninth resistor 1304. In this case, the second voltage distribution switch 1310 may be shorted (ON).

If the second voltage distribution switch 1310 is shorted, the current flow in the second voltage control circuit 819 may be as shown at 1330.

Therefore, the level of the voltage input to the second buffer 817 may be different under the control of the switch 705 of FIG. 7.

The methods according to the embodiments described above may be stored in a computer-readable recording medium that is produced as a program for execution in a computer, and examples of the computer-readable recording medium may include ROM, RAM, CD-ROM, and magnetic tape. , Floppy disks, optical data storage devices, and the like.

The computer readable recording medium can be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. In addition, functional programs, codes, and code segments for implementing the above-described method may be easily inferred by programmers in the art to which the embodiments belong.

It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof.

Accordingly, the above detailed description should not be construed as limiting in all aspects and should be considered as illustrative. The scope of the invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the invention are included in the scope of the invention.

Claims (19)

inverter;
A transmission coil for wirelessly transmitting an AC power signal received from the inverter;
A receiver detector for generating first to second output signals using at least an inverter input voltage applied to the inverter and a coil voltage applied to the transmitting coil; And
A main controller for identifying an object disposed in a charging region based on the first to second output signals, and controlling the inverter input voltage according to the identification result
Wireless power transmission device comprising a. The method of claim 1,
When the main controller detects a receiver disposed in the charging area based on the first to second output signals in a standby state, the main controller increases the inverter input voltage from the first voltage to the second voltage to charge the wireless power transmitter. . The method of claim 2,
During the charging, when the receiver disposed in the charging region is detected based on the first to second output signals, the main controller drops the inverter input voltage from the second voltage to the first voltage to the standby state. Wireless power transmission device to enter. The method of claim 3,
A converter for converting a voltage input from a power supply to generate the first voltage;
A switch configured to ON / OFF control the first voltage applied to the inverter; And
An inverter input voltage controller controlling the switch according to the control of the main controller
Wireless power transmission device further comprising. The method of claim 4, wherein
And the switch is turned on when the receiver is disposed in the charging region in the standby state, and the switch is turned off when the receiver is removed during charging. The method of claim 5,
The receiver has a power rating of 60W class wireless power transmitter. The method of claim 6,
The first voltage is 5V or less, the second voltage is 300V or more wireless power transmitter. The method of claim 7, wherein
And the first to second output signals are further generated using a reference voltage. The method of claim 8,
And the reference voltage is an output voltage of the converter. 10. The method of claim 9,
And the first voltage is generated by output voltage of the converter passing through a diode. The method of claim 10,
And the diode is a protection circuit that blocks the second voltage passing through the switch from being applied to the main controller and the converter. The method of claim 11,
The receiver detector is
And a first comparator and a second comparator, wherein the first to second output signals are outputs of the first comparator and outputs of the second comparator, respectively. The method of claim 12,
The output of the first comparator is determined based on the inverter input voltage and the coil voltage, the output of the second comparator is determined based on the coil voltage and the reference voltage. The method of claim 13,
The receiver detector is
First to second voltage control circuits for dropping levels of the inverter input voltage and the coil voltage according to the control of the main controller;
First to second buffers connected to the first to second voltage control circuits to operate as voltage followers;
First to third filters that respectively drop the output voltages of the first to second buffers and the reference voltages; And
Smoothing circuit converts the coil voltage into direct current
Wireless power transmission device further comprising. The method of claim 14,
The inverter input voltage is connected to a first input terminal of the first comparator through the first voltage control circuit, the first buffer, and the first filter,
The coil voltage is connected to the second input terminal of the first comparator and the first input terminal of the second comparator through the smoothing circuit, the second voltage control circuit, the second buffer, and the second filter,
And the reference voltage is connected to a second input terminal of the second comparator through the third filter. 16. The method of claim 15,
And when the output of the first comparator and the output of the second comparator are both first values in the standby state, the main controller determines that the receiver is disposed in the charging region. The method of claim 16,
When the output of the first comparator and the output of the second comparator are both second values in the standby state, the main controller determines that the foreign material is disposed in the charging region. The method of claim 17,
And the output of the first comparator and the output of the second comparator are both changed to the second value in the charging state, and the main controller determines that the receiver being charged is removed from the charging region. The method of claim 18,
Wherein the first value is HIGH and the second value is LOW.

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