KR20190096888A - Wireless power transmitting apparatus and method - Google Patents

Abstract

The present invention relates to a wireless power transmission device which transmits wireless power to a wireless power reception device. The wireless power transmission device comprises: a transmission power control unit; an alternating current (AC) power generation unit operated in a half bridge operation mode and a full bridge operation mode, and generating square wave shaped power by using direct current (DC) power; a transmission induction coil transmitting the square wave shaped power to a transmission resonance coil by electromagnetic induction; and a transmission resonance coil. The transmission power control unit determines one of the half bridge operation mode and the full bridge operation mode, and provides an AC power generation control signal corresponding to the determined operation mode to the AC power generation unit.

Description

Wireless power transmission apparatus and method {WIRELESS POWER TRANSMITTING APPARATUS AND METHOD}

TECHNICAL FIELD The present invention relates to a wireless power transmission apparatus and method.

Wireless power transmission technology (wireless power transmission or wireless energy transfer), which transfers electric energy wirelessly to a desired device, has already started to use electric motors or transformers using electromagnetic induction principles in the 1800's. A method of transmitting electrical energy by radiating the same electromagnetic wave has also been attempted. Electric toothbrushes and some wireless razors that we commonly use are actually charged with the principle of electromagnetic induction. Electromagnetic induction refers to a phenomenon in which a voltage is induced and a current flows when a magnetic field is changed around a conductor. Electromagnetic induction method is rapidly commercialized around small devices, but there is a problem that the transmission distance of power is short.

Until now, the energy transmission method by the wireless method has a long range transmission technology using magnetic resonance and short wavelength radio frequency in addition to electromagnetic induction.

Recently, among the wireless power transmission technologies, energy transmission schemes using magnetic resonance have been widely used.

In the wireless power transmission system using magnetic resonance, the electric signals formed on the transmitting side and the receiving side are wirelessly transmitted through the coil, so that the user can easily charge an electronic device such as a portable device.

The wireless power transmitter generates AC power having a resonance frequency and transmits the alternating power to the wireless power receiver. At this time, the power transmission efficiency is determined by various causes. There is an increasing demand for an increase in wireless power transfer efficiency.

The present invention is to provide a wireless power transmission apparatus and method that can improve the wireless power transmission efficiency.

An embodiment of the present invention provides a wireless power transmitter for transmitting wireless power to a wireless power receiver, wherein the AC power generating unit operates in a half bridge operation mode and a full bridge operation mode, and generates square wave shape power using a first DC power. ; And a transmission induction coil for transmitting the square wave shape power to the transmission resonance coil by electromagnetic induction.

An embodiment of the present invention provides a wireless power transmitter for transmitting wireless power to a wireless power receiver, comprising: a transmission induction coil configured to transfer applied power to a transmission resonance coil by electromagnetic induction; And a transistor circuit part of a full bridge structure connected to the transmission induction coil.

Also, an embodiment is a wireless power transmission method for transmitting wireless power to a wireless power receiver, comprising: determining one of a half bridge operation mode and a full bridge operation mode; Generating square wave shape power using the first DC power according to the determined operation mode; And transmitting the square wave shape power to the transmission resonance coil by electromagnetic induction through a transmission induction coil unit.

According to the embodiment of the present invention, it is possible to increase the efficiency of the wireless power transmission apparatus.

Further, according to the embodiment of the present invention, circuit breakage due to high current can be prevented.

1 is a view for explaining a wireless power transmission system according to an embodiment of the present invention.
2 is an equivalent circuit diagram of a transmission induction coil according to an embodiment of the present invention.
3 is an equivalent circuit diagram of a power supply device and a wireless power transmission device according to an embodiment of the present invention.
4 is an equivalent circuit diagram of a wireless power receiver according to an embodiment of the present invention.
5 shows a block diagram of a power supply according to an embodiment of the present invention.
6 is a block diagram of an AC power generator and a transmit power controller according to an embodiment of the present invention.
7 is a circuit diagram of a DC-DC converter according to an embodiment of the present invention.
8 is a circuit diagram of a DC-AC converter and a power transmission state detector according to an embodiment of the present invention.
9 is a flowchart illustrating a wireless power transmission method according to an embodiment of the present invention.
10 shows a waveform diagram of nodes in a power supply according to an embodiment of the invention.
11 shows a block diagram of a power supply according to another embodiment of the present invention.
12 is a block diagram of an AC power generator and a transmit power controller according to another embodiment of the present invention.
13 is a circuit diagram of a DC-AC converter and a power transmission state detector according to another embodiment of the present invention.
14 is a flowchart illustrating a wireless power transmission method according to another embodiment of the present invention.
15 shows a waveform diagram of nodes in a power supply according to another embodiment of the present invention.
Figure 16 shows a block diagram of a power supply according to another embodiment of the present invention.
17 is a block diagram of an AC power generator and a transmit power controller according to another embodiment of the present invention.
18 is a circuit diagram of a DC-AC converter and a power transmission state detector according to another embodiment of the present invention.
19 is a flowchart illustrating a wireless power transmission method according to another embodiment of the present invention.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

In addition, when a part is said to "include" a certain component, which means that it may further include other components, except to exclude other components unless otherwise stated.

Hereinafter, a wireless power transmission system according to an embodiment of the present invention will be described with reference to FIGS. 1 to 4.

1 is a view for explaining a wireless power transmission system according to an embodiment of the present invention.

Referring to FIG. 1, the wireless power transmission system may include a power supply device 100, a wireless power transmitter 200, a wireless power receiver 300, and a load 400.

In an embodiment, the power supply device 100 may be included in the wireless power transmission device 200.

The wireless power transmitter 200 may include a transmission induction coil unit 210 and a transmission resonance coil unit 220.

The wireless power receiver 300 may include a reception resonance coil unit 310, a reception induction coil unit 320, and a rectifier 330.

Both ends of the power supply device 100 are connected to both ends of the transmission induction coil unit 210.

The transmission resonant coil unit 220 may be disposed at a predetermined distance from the transmission induction coil unit 210.

The reception resonant coil unit 310 may be disposed at a predetermined distance from the reception induction coil unit 320.

Both ends of the reception induction coil unit 320 are connected to both ends of the rectifier 330, and the load 400 is connected to both ends of the rectifier 330. In an embodiment, the load 400 may be included in the wireless power receiver 300.

The power generated by the power supply device 100 is transmitted to the wireless power transmitter 200, and the power delivered to the wireless power transmitter 200 is resonated with the wireless power transmitter 200 by a resonance phenomenon. The resonance frequency values are transmitted to the same wireless power receiver 300.

Hereinafter, the power transmission process will be described in more detail.

The power supply device 100 generates AC power having a predetermined frequency and transmits the generated AC power to the wireless power transmitter 200.

The transmission induction coil unit 210 and the transmission resonant coil unit 220 are inductively coupled. That is, when an alternating current flows by the power supplied from the power supply device 100, the transmission induction coil unit 210 induces an alternating current in the transmission resonance coil unit 220 which is physically spaced by electromagnetic induction.

Thereafter, the power delivered to the transmission resonant coil unit 220 is transmitted to the wireless power receiver 300 forming the resonance circuit with the wireless power transmitter 200 by resonance.

Power may be transferred by resonance between two impedance matched LC circuits. Such resonance-driven power transfer enables power transfer at higher efficiency over longer distances than power transfer by electromagnetic induction.

The reception resonance coil unit 310 receives power from the transmission resonance coil unit 220 by resonance. Due to the received power, an alternating current flows in the reception resonant coil unit 310. The power transferred to the reception resonance coil unit 310 is transferred to the reception induction coil unit 320 inductively coupled with the reception resonance coil unit 310 by electromagnetic induction. The power delivered to the reception induction coil unit 320 is rectified through the rectifier 330 and transferred to the load 400.

In one embodiment, the transmission induction coil unit 210, the transmission resonant coil unit 220, the reception resonant coil unit 310, and the reception induction coil unit 320 may have a shape such as a circle, an ellipse, and a rectangle. There is no need to be limited.

The transmission resonance coil unit 220 of the wireless power transmitter 200 may transmit power to the reception resonance coil unit 310 of the wireless power receiver 300 through a magnetic field.

Specifically, the transmission resonant coil unit 220 and the reception resonant coil unit 310 are resonantly coupled to operate at a resonant frequency.

Due to the resonance coupling between the transmission resonant coil unit 220 and the reception resonant coil unit 310, power transmission efficiency between the wireless power transmitter 200 and the wireless power receiver 300 may be greatly improved.

Quality factor and coupling coefficient are important in wireless power transmission. That is, the power transmission efficiency may be improved as the quality index and the coupling coefficient have larger values.

The quality factor may refer to an index of energy that may be accumulated in the vicinity of the wireless power transmitter 200 or the wireless power receiver 300.

The quality factor may vary depending on the operating frequency w, the shape, dimensions, materials, and the like of the coil. The quality index can be expressed as Q = w * L / R by the formula. L is the inductance of the coil, and R is the resistance corresponding to the amount of power loss generated in the coil itself.

The quality factor may have an infinite value from 0, and as the quality index increases, power transmission efficiency between the wireless power transmitter 200 and the wireless power receiver 300 may be improved.

Coupling Coefficient refers to the degree of magnetic coupling between the transmitting coil and the receiving coil and has a range of 0 to 1.

Coupling coefficient may vary according to the relative position or distance between the transmitting coil and the receiving coil.

2 is an equivalent circuit diagram of a transmission induction coil unit 210 according to an embodiment of the present invention.

As shown in FIG. 2, the transmission induction coil unit 210 includes a transmission induction coil L1 and a capacitor C1, thereby forming a circuit having appropriate inductance and capacitance values.

The transmission induction coil unit 210 may be configured as an equivalent circuit having both ends of the transmission induction coil L1 connected to both ends of the capacitor C1. That is, the transmission induction coil unit 210 may be configured as an equivalent circuit in which the inductor L1 and the capacitor C1 are connected in parallel.

The capacitor C1 may be a variable capacitor, and impedance matching may be performed as the capacitance of the capacitor C1 is adjusted. Equivalent circuits of the transmission resonant coil unit 220, the reception resonant coil unit 310, and the reception induction coil unit 320 may also be the same as those illustrated in FIG. 2.

3 is an equivalent circuit diagram of the power supply device 100 and the wireless power transmission device 200 according to an embodiment of the present invention.

As shown in FIG. 3, the transmission induction coil unit 210 includes a transmission induction coil L1 having a predetermined inductance value and a capacitor C1 having a predetermined capacitance value. The transmission resonant coil unit 220 includes a transmission resonant coil L2 having a predetermined inductance value and a capacitor C2 having a predetermined capacitance value.

4 is an equivalent circuit diagram of a wireless power receiver 300 according to an embodiment of the present invention.

As shown in FIG. 4, the reception resonance coil unit 310 includes a reception resonance coil L3 having a predetermined inductance value and a capacitor C3 having a predetermined capacitance value. The reception induction coil unit 320 includes a reception induction coil L4 having a predetermined inductance value and a capacitor C4 having a predetermined capacitance value.

The rectifier 330 may convert the AC power received from the reception induction coil unit 320 into DC power and transfer the converted DC power to the load 400.

Specifically, the rectifier 330 may include a rectifier and a smoothing circuit. In one embodiment, the rectifier may be a silicon rectifier, and may be equivalent to the diode D1, as shown in FIG.

The rectifier may convert AC power received from the reception induction coil unit 320 to DC power.

The smoothing circuit may output the smooth DC power by removing the AC component included in the DC power converted by the rectifier. In an exemplary embodiment, as shown in FIG. 4, the rectifying capacitor C5 may be used, but the smoothing circuit is not limited thereto.

The load 400 can be any rechargeable battery or device that requires direct current power. For example, the load 400 may mean a battery.

The wireless power receiver 300 may be mounted on an electronic device that requires power, such as a mobile phone, a notebook, a mouse, and the like. Accordingly, the reception resonance coil unit 310 and the reception induction coil unit 320 may have a shape that matches the shape of the electronic device.

The wireless power transmitter 200 may exchange information with the wireless power receiver 300 using in band or out of band communication.

In band communication may refer to a communication of exchanging information between the wireless power transmitter 200 and the wireless power receiver 300 using a signal having a frequency used for wireless power transmission. The wireless power receiver 300 may further include a switch, and may or may not receive power transmitted from the wireless power transmitter 200 through a switching operation of the switch. Accordingly, the wireless power transmitter 200 may detect an on or off signal of a switch included in the wireless power receiver 300 by detecting the amount of power consumed by the wireless power transmitter 200.

In detail, the wireless power receiver 300 may change the power consumed by the wireless power transmitter 200 by changing the amount of power absorbed by the resistor using a resistor and a switch. The apparatus 200 for transmitting power wirelessly may acquire state information of the apparatus 300 for receiving power wirelessly by detecting a change in power consumption. The switch and resistor can be connected in series. In an embodiment, the state information of the wireless power receiver 300 may include information about the current charge amount and the charge amount trend of the wireless power receiver 300.

More specifically, when the switch is opened, the power absorbed by the resistor becomes 0, and the power consumed by the wireless power transmitter 200 also decreases.

When the switch is shorted, the power absorbed by the resistor is greater than zero, and the power consumed by the wireless power transmitter 200 increases. When the wireless power receiver repeats such an operation, the wireless power transmitter 200 may detect power consumed by the wireless power transmitter 200 to perform digital communication with the wireless power receiver 300.

The wireless power transmitter 200 may receive state information of the wireless power receiver 300 according to the above operation, and may transmit power appropriate thereto.

On the contrary, the wireless power transmitter 200 may be provided with a resistor and a switch to transmit the state information of the wireless power transmitter 200 to the wireless power receiver 300. In an embodiment, the state information of the wireless power transmitter 200 may include the maximum amount of power that the wireless power transmitter 200 may transmit, and the wireless power receiver 300 that the wireless power transmitter 200 provides power. It may include information about the number of available and the amount of available power of the wireless power transmission apparatus 200.

Next, out-of-band communication will be described.

Out-of-band communication refers to a communication for exchanging information for power transmission by using a separate frequency band instead of a resonant frequency band. The wireless power transmitter 200 and the wireless power receiver 300 may exchange information necessary for power transmission by mounting an out-of-band communication module. The out of band communication module may be mounted to a power supply. In one embodiment, the out-of-band communication module may use a short range communication method such as Bluetooth, Zigbee, WLAN, and Near Field Communication (NFC), but is not limited thereto.

Next, a power supply device 100 according to an embodiment of the present invention will be described with reference to FIGS. 5 to 10.

5 shows a block diagram of a power supply according to an embodiment of the present invention.

As shown in FIG. 5, the power supply device 100 according to an embodiment of the present invention may include a power supply unit 110, an oscillator 130, an AC power generator 150, and a power transmission state detector 180. , And a transmission power control unit 190, and the power supply device 100 is connected to the wireless power transmission device 200.

The power supply unit 110 generates DC power, which is power having a DC voltage, and outputs the DC power to the output terminal.

Oscillator 130 generates a small power sine wave.

The power transmission state detector 180 detects a wireless power transmission state between the wireless power transmitter 200 and the wireless power receiver 300.

The transmission power controller 190 generates a control signal for controlling the AC power generator 150 based on the sensed wireless power transmission state.

The AC power generating unit 150 amplifies the power of the small power sine wave of the oscillator 130 by using the DC power of the power supply unit 110 based on the control signal of the transmission power control unit 190 to form a square wave voltage. Generates AC power with

The wireless power transmitter 200 transmits the output power of the AC power generator 150 to the wireless power receiver 300 by resonance.

6 is a block diagram of an AC power generator and a transmit power controller according to an embodiment of the present invention.

As shown in FIG. 6, the AC power generating unit 150 according to an embodiment of the present invention includes an AC power generating control unit 151, a DC-AC converter 153, and a DC-DC converter 155. The transmission power control unit 190 includes a DC power generation control unit 191 and a storage unit 192.

The AC power generation controller 151 generates an AC power generation control signal based on the small power sine wave of the oscillator 130.

The DC power generation control unit 191 controls the DC power generation to allow the DC-DC converter 155 to output power having an output current and a target DC voltage within a target current range based on the detected wireless power transmission state. Generate a signal.

The storage unit 192 stores a lookup table.

The DC-DC converter 155 converts the output power of the power supply 110 into a DC power having an output current and a target DC voltage within a target current range based on the DC power generation control signal.

The DC-AC converter 153 converts the output power of the DC-DC converter 155 into AC power having a square wave AC voltage based on the AC power generation control signal and outputs the AC power to the transmission induction coil unit 210. .

7 is a circuit diagram of a DC-DC converter according to an embodiment of the present invention.

As illustrated in FIG. 7, the DC-DC converter 155 includes an inductor L11, a power switch T11, a diode D11, and a capacitor C11. The power switch T11 may be implemented with a transistor, and in particular, the power switch T11 may be an n-channel metal-oxide-semiconductor field-effect transistor (NMOSFET) but has the same function. It can be replaced by another device capable of doing

One end of the inductor L11 is connected to the output terminal of the power supply unit 110, and the other end is connected to the drain electrode of the power switch T11.

The gate electrode of the power switch T11 is connected to the node A which is an output terminal of the DC power generation control unit 191, and the source electrode is connected to the ground.

The anode electrode of the diode D11 is connected to the drain electrode of the power switch T11, and the cathode electrode is connected to the node B.

One end of the capacitor C11 is connected to the cathode electrode of the diode D11, and the other end is connected to the ground.

8 is a circuit diagram of a DC-AC converter and a power transmission state detector according to an embodiment of the present invention.

As shown in FIG. 8, the DC-AC converter 153 includes a transistor circuit portion having a half bridge structure, and the half bridge transistor circuit portion includes an upper transistor T21, a lower transistor T22, and a DC blocking capacitor C21. It includes, and is connected to the AC power generation control unit 151 and the transmission induction coil unit 210. The power transmission state detecting unit 180 includes a resistor R1 and a voltage difference measuring unit 181, and includes a DC-DC converter 155, a DC-AC converter 153, and a DC power generation controller 191. Is connected to. The DC-AC converter 153 is connected to the DC-DC converter 155 through a resistor R1. The upper transistor T21 and the lower transistor T22 may be n-channel metal-oxide-semiconductor field-effect transistors (NMOS), but may be replaced by other devices having the same function. Can be.

The AC power generation controller 151 has an upper transistor control signal output terminal and a lower transistor control signal output terminal, and generates an AC power generation control signal based on the small power sine wave of the oscillator 130. The AC power generation controller 151 generates the upper transistor control signal as an AC power generation control signal based on the small power sine wave of the oscillator 130, and outputs the upper transistor control signal through the upper transistor control signal output terminal. The AC power generation controller 151 generates the lower transistor control signal as an AC power generation control signal based on the small power sine wave of the oscillator 130, and outputs the lower transistor control signal through the lower transistor control signal output terminal.

The drain electrode of the upper transistor T21 is connected to one end of the resistor R1, and the gate electrode is connected to the upper transistor control signal output terminal of the AC power generation controller 151.

The drain electrode of the lower transistor T22 is connected to the source electrode of the upper transistor T21, the gate electrode is connected to the lower transistor control signal output terminal of the AC power generation controller 151, and the source electrode is connected to ground.

One end of the DC blocking capacitor C21 is connected to the source electrode of the upper transistor T21 and one end of the transmission induction coil L1. The other end of the transmission induction coil L1 is connected to ground.

The voltage difference measuring unit 181 measures a difference in voltage across both ends of the resistor R1.

Next, a wireless power transmission method according to an embodiment of the present invention will be described with reference to FIGS. 9 and 10.

9 is a flowchart illustrating a wireless power transmission method according to an embodiment of the present invention, and FIG. 10 is a waveform diagram of nodes in a power supply device according to an embodiment of the present invention.

In particular, FIG. 9 is a wireless power transmission method in which the embodiment of FIGS. 6 to 8 are embodied.

The power supply unit 110 generates DC power which is power having a DC voltage ( S101 ). In particular, the power supply unit 110 may convert AC power having an AC voltage into DC power which is power having a DC voltage.

The oscillator 130 generates a small power sine wave ( S103 ).

The power transmission state detection unit 180 detects a wireless power transmission state ( S105 ). The power transmission state detector 180 may detect the magnitude of the output current of the DC-DC converter 155 as a wireless power transmission state. Since the voltage across the resistor R1 is proportional to the magnitude of the output current of the DC-DC converter 155, the voltage difference measurer 181 of the power transmission state detector 180 may have both ends of the resistor R1. The difference in voltages across the circuit can be sensed as a wireless power transfer state.

Coupling coefficients may vary according to a distance or a relative position between the wireless power transmitter 200 and the wireless power receiver 300, and thus the wireless power transmission state may also be changed. That is, as the distance between the wireless power transmitter 200 and the wireless power receiver 300 increases, the coupling coefficient may decrease, resulting in poor wireless power transmission. As the wireless power transmission state worsens, even if the wireless power transmitter 200 transmits the same power to the wireless power receiver 300, the transmission efficiency is not good, and thus, more power is consumed. Therefore, the power transmission state detection unit 180 may detect the wireless power transmission state based on the magnitude of the output current of the DC-DC converter 155.

Since the output current of the DC-DC converter 155 may not be kept constant, the power transmission state detector 180 may measure the magnitude of the output peak-to-peak current of the DC-DC converter 155. It may be.

The DC power generation control unit 191 generates DC power to allow the DC-DC converter 155 to output DC power having a current within a target current range and a target DC voltage based on the detected wireless power transmission state. A control signal is generated ( S107 ) and output to the gate electrode of the transistor T11. In this case, the target current range may be constant regardless of the magnitude of the target DC voltage, or may vary according to the magnitude of the target DC voltage. In addition, the target current range may be a target peak-to-peak current range. As illustrated in FIG. 10, the DC power generation control signal may be a pulse width modulation (PWM) signal that continues in all sections. The DC power generation controller 191 may determine the duty ratio of the PWM signal based on the detected wireless power transmission state.

In one embodiment, the voltage difference measuring unit 181 obtains the measured output current value based on the voltage difference between the both ends of the resistor R1. Then, when the measured output current value is out of the reference range, the DC power generation control unit 191 changes the duty rate, and transmits the DC power generation control signal of the pulse width modulated signal having the changed duty rate to the gate electrode of the transistor T11. The output current of the DC-DC converter 155 is within the reference range. Specifically, when the measured output current value is larger than the reference range, the DC power generation control unit 191 decreases the duty rate and transmits the DC power generation control signal of the pulse width modulated signal having the reduced duty rate to the gate electrode of the transistor T11. Output to the DC-DC converter 155 so that the output current value is within a reference range. In addition, when the measured output current value is smaller than the reference range, the DC power generation control unit 191 increases the duty rate, and transmits the DC power generation control signal of the pulse width modulated signal having the increased duty rate to the gate electrode of the transistor T11. The output current of the DC-DC converter 155 is within the reference range.

In another embodiment, the storage unit 192 may have a lookup table indicating a relationship between the plurality of measured output power values and the plurality of target output voltage values. Table 1 shows a lookup table showing the relationship between a plurality of measured output power values and a plurality of target output voltage values according to an embodiment of the present invention.

Measure output power Target output voltage 10 W or less 12 V 10 to 12 W 14 V 12 to 14 W 16 V 14 to 16 W 18 V 16-18 W 20 V 18-20 W 22 V 20 W or more 24 V

At this time, the voltage difference measuring unit 181 obtains the measured output current value based on the voltage difference between both ends of the resistor R1. Thereafter, the DC power generation control unit 191 obtains the measured output power value which is the current output power of the DC-DC converter 155 based on the measured output current value, and the target output voltage value corresponding to the measured output power value. In the lookup table, the duty ratio of the PWM signal is determined using the voltage of the node B as feedback information so that the output voltage of the DC-DC converter 155 becomes a target output voltage value, and according to the duty rate The DC power generation control signal may be generated.

In another embodiment, the storage unit 192 may have a lookup table indicating a relationship between the plurality of measured output current values and the plurality of target output voltage values. At this time, the voltage difference measuring unit 181 obtains the measured output current value based on the voltage difference between both ends of the resistor R1. Thereafter, the DC power generation controller 191 finds a target output voltage value corresponding to the measured output current value in the look-up table, and outputs a node (so that the output voltage of the DC-DC converter 155 becomes the target output voltage value). The duty ratio of the PWM signal may be determined using the voltage of B) as feedback information, and a DC power generation control signal according to the duty rate may be generated.

Table 2 shows a lookup table according to an embodiment of the present invention.

Measured output current at initial output voltage Coupling coefficient Target output voltage Proper current range 100 mA or less 0.03 or less 30 V 801 to 851 mA 101 to 150 mA 0.05 28 V 751 to 800 mA 151 to 200 mA 0.08 26 V 701 to 751 mA 201 to 250 mA 0.11 24 V 651 to 700 mA 251 to 300 mA 0.14 22 V 601 to 650 mA 301 to 350 mA 0.17 20 V 551 to 600 mA 351 mA or more 0.20 or more 18 V 501 to 550 mA

As shown in Table 2, the storage unit 192 has a lookup for matching the output current value of the DC-DC converter 155, the coupling coefficient, the output voltage value of the DC-DC converter 155, and an appropriate current range. You can have a table.

When the DC-DC converter 155 outputs DC power having an initial output voltage value and the output current of the DC-DC converter 155 is 100 mA or more, the wireless power receiver 300 is detected. can see. The initial output voltage may be 12V, but this is only an example.

If the output current of the DC-DC converter 155 is 120 mA when the DC-DC converter 155 outputs DC power having an initial output voltage value, the wireless power transmitter 200 transmits it. The coupling coefficient of the resonance coil unit 220 and the reception resonance coil unit 310 of the wireless power receiver 300 corresponds to 0.05. In this case, the DC power generation controller 191 determines that the wireless power receiver 300 is far from the wireless power transmitter 200, and the output voltage of the DC-DC converter 155 is 28V. The DC-DC converter 155 is controlled so as to be possible.

Then, when the magnitude of the output voltage of the DC-DC converter 155 is maintained at 28V, the DC power generation control unit 191 has an appropriate current range 751 of the magnitude of the output current of the DC-DC converter 155. ~ 800mA).

If the magnitude of the output current of the DC-DC converter 155 is out of an appropriate current range, the DC power generation controller 191 determines that the magnitude of the output voltage of the DC-DC converter 155 is the magnitude of the initial output voltage. The DC-DC converter 155 is controlled to be 12V. When the output current of the DC-DC converter 155 is 180 mA, the controller 270 determines that the distance between the wireless power transmitter 200 and the wireless power receiver 300 is closer than that of the 120 mA. The DC-DC converter 155 is controlled so that the output voltage of the DC-DC converter 155 is 26V.

In the above example, the distance between the wireless power transmitter 200 and the wireless power receiver 300 has been described in relation to the strength of the current, but in addition, the direction in which the wireless power transmitter 200 and the wireless power receiver 300 are placed. Various wireless power transfer states may be considered.

As such, the wireless power transmitter 200 adjusts the power transmitted to the wireless power receiver 300 in consideration of various wireless power transmission states such as a distance and a direction of the wireless power receiver 300, thereby maximizing power transmission efficiency. Can prevent the power loss.

The DC-DC converter 155 converts the output power of the power supply 110 into a DC power having an output current and a target DC voltage within a target current range based on the DC power generation control signal ( S109 ). The magnitude of the output voltage of the DC-DC converter 155 may be equal to the magnitude of the output voltage of the power supply 110, or may be greater than or less than the magnitude of the output voltage of the power supply 110.

The AC power generation controller 151 generates an AC power generation control signal based on the small power sine wave of the oscillator 130 ( S111 ). The AC power generation controller 151 may generate the upper transistor control signal as an AC power generation control signal based on the small power sine wave of the oscillator 130, and output the upper transistor control signal through the upper transistor control signal output terminal. The AC power generation controller 151 may generate the lower transistor control signal as the AC power generation control signal based on the small power sine wave of the oscillator 130, and output the lower transistor control signal through the lower transistor control signal output terminal.

An upper transistor control signal and a lower transistor control signal will be described with reference to FIG. 10.

As shown in Fig. 10, the upper transistor control signal and the lower transistor control signal are square waves.

One period of the upper transistor control signal includes a turn-on time slot of the upper transistor T21 and a turn-off time slot of the upper transistor T21 in that order. The turn-on time slot of the upper transistor T21 may correspond to a half cycle of the small power sine wave of the oscillator 130, and the turn-off time slot of the upper transistor T21 may correspond to the remaining half cycle of the small power sine wave.

One period of the lower transistor control signal includes a turn-on time slot of the lower transistor T22 and a turn-off time slot of the lower transistor T22 in that order. The turn-on time slot of the lower transistor T22 may correspond to a half cycle of the small power sine wave, and the turn-off time slot of the lower transistor T22 may correspond to the remaining half cycle of the small power sine wave.

In the turn-on time slot of the upper transistor T21, the upper transistor control signal has a level for turning on the upper transistor T21. The level for turning on the upper transistor T21 may be a high level.

The upper transistor control signal has a level for turning off the upper transistor T21 in the turn-off time slot of the upper transistor T21. The level for turning off the upper transistor T21 may be a low level.

The lower transistor control signal has a level for turning on the lower transistor T22 in the turn-on time slot of the lower transistor T22. The level for turning on the lower transistor T22 may be a high level.

The lower transistor control signal has a level for turning off the upper transistor T22 in the turn-off time slot of the lower transistor T22. The level for turning off the lower transistor T22 may be a low level.

In the turn-on time slot of the upper transistor T21, the lower transistor control signal of the turn-off time slot of the lower transistor T22 has a level for turning off the lower transistor T22.

In the turn-on time slot of the lower transistor T22, the lower transistor control signal of the turn-off time slot of the upper transistor T21 has a level for turning off the lower transistor T22.

In order to prevent a short circuit due to simultaneous turn-on of the upper transistor T21 and the lower transistor T22, the upper transistor control signal and the lower transistor control signal may have a dead time slot.

In order to output power having a square wave voltage of 50% duty ratio, the turn-on time slot of the upper transistor T21 has a time length of (50-a)% of one period T, and the dead time of the upper transistor T21. The slot has a time length of a% of one period T, the turn-off time slot of the upper transistor T21 has a time length of 50%, and the turn-on time slot of the lower transistor T22 is one period T. The dead time slot of the lower transistor T22 has a time length of a% of one period T, and the turn-off time slot of the lower transistor T22 is 50%. It can have a length of time. For example, a may be 1%.

The DC-AC converter 153 converts the output power of the DC-DC converter 155 into AC power having a square wave AC voltage based on the AC power generation control signal ( S113 ), and transmits to the transmission induction coil unit 210. Output

An operation of the DC-AC converter 153 will be described with reference to FIG. 10.

The upper transistor T21 and the lower transistor T22 output the square wave power having the square wave voltage V3 as shown in FIG. 10 by the upper transistor control signal and the lower transistor control signal having the dead time slot.

The DC blocking capacitor C21 cuts the DC voltage of the square wave power and outputs the square wave AC power having the square wave AC voltage V4 to the transmission induction coil unit 210.

The wireless power transmitter 200 transmits square wave AC power having a square wave AC voltage to the wireless power receiver 300 by resonance ( S115 ).

Next, a power supply device 100 according to another embodiment of the present invention will be described with reference to FIGS. 11 to 15.

11 shows a block diagram of a power supply according to another embodiment of the present invention.

As shown in FIG. 11, the power supply device 100 according to another embodiment of the present invention may include a power supply unit 110, an oscillator 130, an AC power generator 160, and a power transmission state detector 180. And a transmission power control unit 190, and the power supply device 100 is connected to the wireless power transmission device 200.

The power supply unit 110 generates DC power, which is power having a DC voltage, and outputs the DC power to the output terminal.

Oscillator 130 generates a small power sine wave.

The power transmission state detector 180 detects a wireless power transmission state.

The transmission power controller 190 generates a control signal for controlling the AC power generator 160 based on the detected wireless power transmission state and the small power sine wave of the oscillator 130.

The AC power generating unit 160 amplifies the power of the small power sine wave of the oscillator 130 using the DC power of the power supply 110 based on the control signal of the transmission power control unit 190 to form a square wave voltage. Generates AC power with

The wireless power transmitter 200 transmits the output power of the AC power generator 160 to the wireless power receiver 300 by resonance.

12 is a block diagram of an AC power generator and a transmit power controller according to another embodiment of the present invention.

As shown in FIG. 12, the AC power generator 160 according to an embodiment of the present invention includes a DC-AC converter 163, and the transmission power controller 190 includes the AC power generator 193. It includes.

The AC power generation control unit 193 generates an AC power generation control signal based on the small power sine wave of the oscillator 130. The AC power generation control unit 193 may generate an AC power generation control signal that enables the power supply unit 110 to output DC power having an output current within a target current range based on the detected wireless power transmission state. Can be. The target current range may be a target peak-to-peak current range.

The DC-AC converter 163 converts the output power of the power supply 110 into AC power having a square wave AC voltage based on the AC power generation control signal, and outputs the AC power to the transmission induction coil unit 210.

13 is a circuit diagram of a DC-AC converter and a power transmission state detector according to another embodiment of the present invention.

As shown in Fig. 13, the DC-AC converter 163 includes a full bridge transistor circuit portion, and the full bridge transistor circuit portion includes two half bridge transistor circuit portions. One of the two half bridge transistor circuit portions includes an upper transistor T41 and a lower transistor T42, and the other includes an upper transistor T44 and a lower transistor T43. The upper transistors T41 and T44 and the lower transistors T42 and T43 may be n-channel metal-oxide-semiconductor field-effect transistors (NMOS), but may have the same function. It may be replaced by another device.

The power transmission state detecting unit 180 includes a resistor R1 and a voltage difference measuring unit 181, and is connected to the power supply unit 110, the DC-AC converter 163, and the AC power generation control unit 193. . The DC-AC converter 163 is connected to the power supply 110 through the resistor R1.

The AC power generation control unit 193 has first and second upper transistor control signal output terminals and first and second lower transistor control signal output terminals, and based on the small power sine wave and the wireless power transmission state of the oscillator 130, AC power. Generate the generation control signal.

The drain electrode of the upper transistor T41 is connected to one end of the resistor R1, the gate electrode is connected to the first upper transistor control signal output terminal of the AC power generation control unit 193, and the source electrode is the transmit induction coil L1. Is connected to one end.

The drain electrode of the lower transistor T42 is connected to the source electrode of the upper transistor T41, the gate electrode is connected to the first lower transistor control signal output terminal of the AC power generation control unit 193, and the source electrode is connected to ground. .

The drain electrode of the upper transistor T44 is connected to one end of the resistor R1, the gate electrode is connected to the second upper transistor control signal output terminal of the AC power generation control unit 193, and the source electrode is the transmit induction coil L1. Is connected to the other end of the

The drain electrode of the lower transistor T43 is connected to the source electrode of the upper transistor T44, the gate electrode is connected to the second lower transistor control signal output terminal of the AC power generation control unit 193, and the source electrode is connected to ground. .

The voltage difference measuring unit 181 measures a difference in voltage across both ends of the resistor R1.

Next, a wireless power transmission method according to another embodiment of the present invention will be described with reference to FIGS. 14 and 15.

14 is a flowchart illustrating a wireless power transmission method according to another embodiment of the present invention, and FIG. 15 is a waveform diagram of nodes in a power supply device according to another embodiment of the present invention.

In particular, FIG. 14 is a wireless power transmission method in which the embodiment of FIGS. 11 to 13 are embodied.

The power supply unit 110 generates DC power which is power having a DC voltage ( S301 ). In particular, the power supply unit 110 may convert AC power having an AC voltage into DC power which is power having a DC voltage.

The oscillator 130 generates a small power sine wave ( S303 ).

The power transmission state detection unit 180 detects the wireless power transmission state ( S305 ). The power transmission state detector 180 may detect the magnitude of the output current of the power supply 110 as a wireless power transmission state. Since the voltage across the resistor R1 is proportional to the magnitude of the output current of the power supply 110, the voltage difference measurer 181 of the power transmission state detector 180 may have a voltage across the resistor R1. Can be detected as a wireless power transfer state. Since the output current of the power supply unit 110 may not be kept constant, the power transmission state detection unit 180 may measure the magnitude of the output peak-to-peak current of the power supply unit 110 as a wireless power transmission state. have.

The AC power generation control unit 193 generates an AC power generation control signal for allowing the power supply unit 110 to output DC power having an output current within a target current range based on the detected wireless power transmission state ( S311 ), and outputs to DC-AC converter 163. Since the output current of the power supply 110 may not be kept constant, the power transmission state detection unit 180 may measure the magnitude of the peak-to-peak output current of the power supply 110.

In one embodiment, the AC power generation control unit 193 determines an operation mode of the DC-AC converter 163 based on the detected wireless power transmission state, and generates an AC power generation control signal for the operation mode. Output to the DC-AC converter 163. In this case, the operation mode may be one of a full bridge operation mode and a half bridge operation mode. The voltage difference measuring unit 181 obtains the measured output current value based on the voltage difference between the both ends of the resistor R1. The DC power generation controller 191 may compare the measured output current value with the reference value and determine the operation mode of the DC-AC converter 163 according to the comparison result.

In this case, the reference value may be an appropriate current range of Table 2 set according to the initial output voltage value.

When the measured output current value is larger than the reference value, the DC power generation controller 191 may determine the operation mode of the DC-AC converter 163 as the full bridge operation mode. When the measured output current value is smaller than the reference value, the DC power generation controller 191 may determine the operation mode of the DC-AC converter 163 as the half bridge operation mode.

In the half bridge mode of operation, the AC power generation control unit 193 operates one of the two half bridge transistor circuit sections and stops the other one. The AC power generation control unit 193 turns off the upper transistor of the half-bridge transistor circuit portion in which the operation is stopped, and turns on the lower transistor. The AC power generation control unit 193 provides a control signal as described with reference to FIG. 10 to the half bridge transistor circuit to be operated.

In the full bridge operation mode, the AC power generation controller 193 alternately provides a control signal for one half of a cycle and a control signal for the other half of the cycle to the DC-AC converter 163. In one half of the period, the upper transistor T41 of one half bridge transistor circuit portion is turned on and the lower transistor T42 is turned off, and the upper transistor T44 of the other half bridge transistor circuit portion is turned off and the lower transistor is turned off. T43 is turned on. In the other half of one period, the upper transistor T41 of one half bridge transistor circuit portion is turned off and the lower transistor T42 is turned on, and the upper transistor T44 of the other half bridge transistor circuit portion is turned on and the lower transistor is turned on. T43 is turned off. The two transistor modes of operation may be synchronized to the small power sine wave of oscillator 130. In order to prevent a short circuit due to simultaneous turn-on of the upper transistor and the lower transistor, the upper transistor control signal and the lower transistor control signal may have a dead time slot.

In another embodiment, the voltage difference measuring unit 181 obtains the measured output current value based on the voltage difference between the both ends of the resistor R1, and the DC power generation control unit 191 supplies the power based on the measured output current value. The measured output power value that is the current output power of the supply unit 110 may be obtained, and the operation mode of the DC-AC converter 163 may be determined based on the measured output power value. In this case, the operation mode may be one of a full bridge operation mode and a half bridge operation mode. The DC power generation controller 191 may compare the measured output power value with the reference value and determine the operation mode of the DC-AC converter 163 according to the comparison result. In this case, the reference value may be a reference power value calculated from an appropriate current range of Table 2 set according to the initial output voltage value.

When the measured output power value is larger than the reference value, the DC power generation controller 191 may determine the operation mode of the DC-AC converter 163 as the full bridge operation mode. When the measured output power value is smaller than the reference value, the DC power generation controller 191 may determine the operation mode of the DC-AC converter 163 as the half bridge operation mode.

The DC-AC converter 163 converts the output power of the power supply 110 into AC power having a square wave AC voltage V3 based on the AC power generation control signal ( S313 ), and transmits the converted power to the induction coil unit 210. Output

The wireless power transmitter 200 transmits the square wave AC power having the square wave AC voltage V3 to the wireless power receiver 300 by resonance ( S315 ).

Next, a power supply device 100 according to another embodiment of the present invention will be described with reference to FIGS. 16 to 19.

Figure 16 shows a block diagram of a power supply according to another embodiment of the present invention.

As shown in FIG. 16, the power supply device 100 according to another embodiment of the present invention may include a power supply unit 110, an oscillator 130, an AC power generator 170, and a power transmission state detector 180. And a transmission power control unit 190, and the power supply device 100 is connected to the wireless power transmission device 200.

The power supply unit 110 generates DC power, which is power having a DC voltage, and outputs the DC power to the output terminal.

Oscillator 130 generates a small power sine wave.

The power transmission state detector 180 detects a wireless power transmission state.

The transmission power controller 190 generates a control signal for controlling the AC power generator 170 based on the detected wireless power transmission state and the small power sine wave of the oscillator 130.

The AC power generating unit 170 amplifies the power of the small power sine wave of the oscillator 130 by using the DC power of the power supply unit 110 based on the control signal of the transmission power control unit 190 to form a square wave voltage. Generates AC power with

The wireless power transmitter 200 transmits the output power of the AC power generator 170 to the wireless power receiver 300 by resonance.

17 is a block diagram of an AC power generator and a transmit power controller according to another embodiment of the present invention.

As shown in FIG. 17, the AC power generator 170 according to an exemplary embodiment of the present invention includes a DC-DC converter 175 and a DC-AC converter 173, and the transmission power controller 190. ) Includes a DC power generation control unit 191, a storage unit 192, and an AC power generation control unit 193.

The DC power generation controller 191 generates DC power such that the DC-DC converter 175 outputs DC power having an output current and a target DC voltage within a target current range based on the detected wireless power transmission state. Generate a control signal.

The storage unit 192 stores a lookup table.

The DC-DC converter 175 converts the output power of the power supply 110 into a DC power having an output current and a target DC voltage within a target current range based on the DC power generation control signal.

The AC power generation control unit 193 generates an AC power generation control signal based on the small power sine wave of the oscillator 130. The AC power generation control unit 193 may further control the AC power generation control signal to allow the DC-DC converter 175 to output DC power having an output current within a target current range based on the detected wireless power transmission state. Can be generated. The target current range may be a target peak-to-peak current range.

The DC-AC converter 173 converts the output power of the DC-DC converter 175 into square wave power based on the AC power generation control signal and outputs the square wave shape power to the transmission induction coil unit 210.

18 is a circuit diagram of a DC-AC converter and a power transmission state detector according to another embodiment of the present invention.

As shown in Fig. 18, the DC-AC converter 173 includes a full bridge transistor circuit portion, which includes two half bridge transistor circuit portions. One of the two half bridge transistor circuit sections includes an upper transistor T61 and a lower transistor T62, and the other includes an upper transistor T64 and a lower transistor T63. The upper transistors T61 and T64 and the lower transistors T62 and T63 may be n-channel metal-oxide-semiconductor field-effect transistors (NMOS), but may have the same function. It may be replaced by another device.

The power transmission state detecting unit 180 includes a resistor R1 and a voltage difference measuring unit 181, and includes a DC-DC converter 175, a DC-AC converter 173, and an AC power generation controller 193. Is connected to. The DC-AC converter 173 is connected to the DC-DC converter 175 through a resistor R1.

The AC power generation control unit 193 has first and second upper transistor control signal output terminals and first and second lower transistor control signal output terminals, and based on the small power sine wave and the wireless power transmission state of the oscillator 130, AC power. Generate the generation control signal.

The drain electrode of the upper transistor T61 is connected to one end of the resistor R1, the gate electrode is connected to the first upper transistor control signal output terminal of the AC power generation control unit 193, and the source electrode is the transmit induction coil L1. Is connected to one end.

The drain electrode of the lower transistor T62 is connected to the source electrode of the upper transistor T61, the gate electrode is connected to the first lower transistor control signal output terminal of the AC power generation control unit 193, and the source electrode is connected to ground. .

The drain electrode of the upper transistor T64 is connected to one end of the resistor R1, the gate electrode is connected to the second upper transistor control signal output terminal of the AC power generation control unit 193, and the source electrode is the transmit induction coil L1. Is connected to the other end of the

The drain electrode of the lower transistor T63 is connected to the source electrode of the upper transistor T64, the gate electrode is connected to the second lower transistor control signal output terminal of the AC power generation control unit 193, and the source electrode is connected to ground. .

The voltage difference measuring unit 181 measures a difference in voltage across both ends of the resistor R1.

Next, a wireless power transmission method according to another embodiment of the present invention will be described with reference to FIG. 19.

19 is a flowchart illustrating a wireless power transmission method according to another embodiment of the present invention.

In particular, FIG. 19 is a wireless power transmission method in which the embodiment of FIGS. 16 to 18 is embodied.

The power supply unit 110 generates DC power which is power having a DC voltage ( S501 ). In particular, the power supply unit 110 may convert AC power having an AC voltage into DC power which is power having a DC voltage.

The oscillator 130 generates a small power sine wave ( S503 ).

The power transmission state detection unit 180 detects the wireless power transmission state ( S505 ). The power transmission state detection unit 180 may detect the magnitude of the output current of the DC-DC converter 175 as the power transmission state. Since the voltage across the resistor R1 is proportional to the magnitude of the output current of the power supply 110, the voltage difference measurer 181 of the power transmission state detector 180 may have a voltage across the resistor R1. Can be detected as a wireless power transfer state. Since the output current of the DC-DC converter 175 may not be kept constant, the power transmission state detector 180 may measure the magnitude of the output peak-to-peak current of the DC-DC converter 175. It may be.

The DC power generation control unit 191 generates DC power to allow the DC-DC converter 175 to output DC power having a current within a target current range and a target DC voltage based on the detected wireless power transmission state. A control signal is generated ( S507 ) and output to the gate electrode of the transistor T11. Step S507 may be embodied by step S107 described above.

The DC-DC converter 175 converts the output power of the power supply 110 into a DC power having an output current and a target DC voltage within a target current range based on the DC power generation control signal ( S509 ).

The AC power generation control unit 193 may generate an AC power generation control signal for allowing the DC-DC converter 175 to output DC power having an output current within a target current range based on the detected wireless power transmission state. It produces | generates ( S511 ), and outputs it to the DC-AC conversion part 173. Step S511 may be embodied by step S311 described above.

The DC-AC converter 173 converts the output power of the power supply 110 into AC power having a square wave AC voltage V3 based on the AC power generation control signal ( S513 ) and transmits it to the transmission induction coil unit 210. Output

The wireless power transmitter 200 transmits the square wave AC power having the square wave AC voltage V3 to the wireless power receiver 300 by resonance ( S515 ).

Features, structures, effects, and the like described in the above embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, and the like illustrated in the embodiments may be combined or modified with respect to other embodiments by those skilled in the art to which the embodiments belong. Therefore, contents related to such combinations and modifications should be construed as being included in the scope of the present invention.

Although the above description has been made based on the embodiments, these are merely examples and are not intended to limit the present invention. Those skilled in the art to which the present invention pertains may not have been exemplified above without departing from the essential characteristics of the present embodiments. It will be appreciated that many variations and applications are possible. For example, each component specifically shown in the embodiment can be modified. And differences relating to such modifications and applications will have to be construed as being included in the scope of the invention defined in the appended claims.

Claims (37)

A power supply for supplying DC power;
A detector for detecting a power transmission state;
An AC power generator converting the DC power into AC power;
A controller configured to determine an operation mode of the AC power generator; And
It includes a coil unit to which the AC power is input,
The operation mode includes a half bridge operation mode and a full bridge operation mode,
The control unit,
Determine one of the half bridge mode of operation or the full bridge mode of operation based on the power transfer state;
Providing an AC power generation control signal corresponding to the determined operation mode to the AC power generation unit
Wireless power transmission device. The method of claim 1,
The AC power generator includes a transistor circuit of a full bridge structure.
Wireless power transmitter. The method of claim 2,
The transistor circuit part of the full bridge structure
A first transistor including a drain electrode to which the DC power is applied and a source electrode connected to one end of the coil part;
A second transistor including a drain electrode connected to the source electrode of the first transistor and a source electrode connected to the ground;
A third transistor including a drain electrode to which the DC power is applied and a source electrode connected to the other end of the coil unit; And
And a fourth transistor including a drain electrode connected to the source electrode of the third transistor and a source electrode connected to the ground.
Wireless power transmitter. The method of claim 3,
When determined to the half-bridge operation mode,
The control unit,
Turn off the third transistor, turn on the fourth transistor,
Turn on the first transistor and turn off the second transistor in half of one cycle,
Turning off the first transistor and turning on the second transistor in the other half period.
Wireless power transmitter. The method of claim 3,
If it is determined that the full bridge operating mode,
The control unit,
Turning on the first and fourth transistors and turning off the second and third transistors in one half of a period,
Turning off the first and fourth transistors and turning on the second and third transistors in the other half period.
Wireless power transmitter. The method of claim 1,
The power transmission state is determined based on a coupling coefficient between the wireless power transmitter and the wireless power receiver.
Wireless power transmitter. Supplying direct current power;
Detecting a power transfer state;
Converting the DC power into AC power in an AC power generator;
Determining an operation mode of the AC power generator; And
Inputting the converted AC power to a coil unit;
The operation mode includes a half bridge operation mode and a full bridge operation mode,
Determining an operation mode of the AC power generation unit,
Determining one of the half bridge mode of operation or the full bridge mode of operation based on the power transfer state; And
Providing an AC power generation control signal corresponding to the determined operation mode to the AC power generation unit;
Wireless power transmission method. The method of claim 7, wherein
The AC power generator includes a transistor circuit of a full bridge structure,
The transistor circuit part of the full bridge structure
A first transistor including a drain electrode to which the DC power is applied and a source electrode connected to one end of the coil part;
A second transistor including a drain electrode connected to the source electrode of the first transistor and a source electrode connected to the ground;
A third transistor including a drain electrode to which the DC power is applied and a source electrode connected to the other end of the coil unit; And
And a fourth transistor including a drain electrode connected to the source electrode of the third transistor and a source electrode connected to the ground.
Wireless power transmission method. The method of claim 8,
Determining an operation mode of the AC power generation unit,
Determining an operation mode of the AC power generator as the half bridge operation mode;
Turning off the third transistor and turning on the fourth transistor when the half bridge operating mode is determined;
Turning on the first transistor and turning off the second transistor in half of one period; And
Turning off the first transistor and turning on the second transistor in the other half period;
Wireless power transmission method. The method of claim 8,
Determining an operation mode of the AC power generation unit,
Determining an operation mode of the AC power generator as the full bridge operation mode;
Turning on the first and fourth transistors and turning off the second and third transistors in half of one period; And
Turning off the first and fourth transistors and turning on the second and third transistors in the other half period.
Wireless power transmission method. The method of claim 7, wherein
The power transmission state is determined based on a coupling coefficient between the wireless power transmitter and the wireless power receiver.
Wireless power transmission method. Providing DC power to the AC power generator;
Generating alternating current power having a preset frequency to transmit wireless power;
Detecting a change in the wireless power consumption controlled by a switch and a resistance of a wireless power receiver;
Determining state information of the wireless power receiver based on the change;
Transmitting wireless power generated by the AC power generator; And
The wireless power includes one of a first waveform and a second waveform different from the first waveform based on the state information of the wireless power receiver.
Control method of a wireless power transmission device. The method of claim 11,
The AC power generator includes a full bridge transistor circuit for operating in a full bridge mode or a half bridge mode.
Control method of a wireless power transmission device. The method of claim 12,
The AC power generator is operated in the half bridge mode to transmit the first waveform.
Control method of a wireless power transmission device. The method of claim 13,
The AC power generator is operated in the full bridge mode to transmit the second waveform.
Control method of a wireless power transmission device. The method of claim 12,
The full bridge transistor circuit includes a first half bridge circuit and a second half bridge circuit.
Control method of a wireless power transmission device. The method of claim 15,
The AC power generator may include a controller configured to operate the first half bridge circuit and stop the operation of the second half bridge circuit in the half bridge mode.
Control method of a wireless power transmission device. The method of claim 16,
The controller is configured to operate the first half bridge circuit and the second half bridge circuit in the full bridge mode.
Control method of a wireless power transmission device. The method of claim 12,
Detecting the change in wireless power consumption comprises detecting power consumption of the wireless power transmitter based on the switch being opened or closed and connected in series with the resistor.
Control method of a wireless power transmission device. The method of claim 12,
The change is detected based on the magnitude of the output current of the direct current power supplied to the alternator
Control method of a wireless power transmission device. The method of claim 19,
The AC power generator includes a DC-DC converter and a DC-AC converter,
The variation is detected based on the level of the output current of the DC-DC converter
Control method of a wireless power transmission device. The method of claim 12,
The state information of the wireless power receiver includes a change in the amount of charge of the wireless power.
Control method of a wireless power transmission device. The method of claim 12,
The state information of the wireless power receiver includes a maximum power of the wireless power transmitter and available power of the wireless power transmitter. The method of claim 12,
The AC power has the first waveform or the second waveform different from the first waveform based on the state information of the wireless power receiver.
Control method of a wireless power transmission device. An AC power generator for generating AC power having a predetermined frequency to transmit wireless power; And
Including a control unit,
The control unit,
Detect a change in wireless power consumption controlled by a switch and a resistance of the wireless power receiver,
Determine the state information of the wireless power receiver based on the change,
Transmit the wireless power generated by the AC power generation unit,
The wireless power includes one of a first waveform and a second waveform different from the first waveform based on the state information of the wireless power receiver.
Wireless power transmitter. The method of claim 24,
The AC power generator includes a full bridge transistor circuit for operating in a full bridge mode or a half bridge mode.
Wireless power transmitter. The method of claim 25,
The AC power generating unit operates in a half bridge mode for transmitting the first waveform.
Wireless power transmitter. The method of claim 26,
The AC power generating unit operates in a full bridge mode to transmit the second waveform.
Wireless power transmitter. The method of claim 25,
The full bridge transistor circuit includes a first half bridge circuit and a second half bridge circuit.
Wireless power transmitter. The method of claim 28,
The control unit operates the first half bridge circuit and stops the operation of the second half bridge circuit in the half bridge mode.
Wireless power transmitter. The method of claim 29,
The controller is configured to operate the first half bridge circuit and the second half bridge circuit in the full bridge mode.
Wireless power transmitter. The method of claim 25,
The control unit detects a change in the wireless power consumption by opening or closing the switch and connected in series with the resistor to detect power consumption of the wireless power transmitter.
Wireless power transmitter. The method of claim 25,
The change is detected according to the magnitude of the output current of the direct current power supplied to the alternator
Wireless power transmitter. 33. The method of claim 32,
The AC power generating unit includes a DC-DC converter and a DC-AC converter,
The variation is detected based on the level of the output current of the DC-DC converter
Wireless power transmitter. The method of claim 25,
The state information of the wireless power receiver includes a change in the amount of charge of the wireless power.
Wireless power transmitter. The method of claim 25,
The state information of the wireless power receiver includes the maximum power of the wireless power transmitter and the available power of the wireless power transmitter.
Wireless power transmitter. The method of claim 25,
And the AC power has the second waveform different from the first waveform or the first waveform based on state information of the wireless power receiver.

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