KR20150082860A - Power generator, apparatus for transmitting wireless power and system for transferring wireless power - Google Patents

Abstract

A power generator comprises: an alternative power control part which generates first to fourth alternative power control signals in accordance with PWM control signals; a transistor circuit part which has a full bridge structure; and a DC-AC converting part which generates alternative power including positive polarity voltage and negative polarity voltage in response to the first to fourth alternative power control signals. The DC-AC converting part generates positive voltage in response to the first alternative power control signal and the fourth alternative power control signal and generates negative voltage in response to a second alternative power control signal and a third alternative power control signal. Duty ratio of positive polarity voltage is determined by polling time of the fourth alternative power control signal and duty ratio of negative polarity voltage is determined by polling time of the third alternative power control signal.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power generation apparatus, a wireless power transmission apparatus,

Embodiments relate to wireless power transmission techniques.

In the 1800s, electric motors and transformers using electromagnetic induction principles began to be used, and then radio waves and lasers were used to transmit the electric energy to the desired devices wirelessly. A method of transmitting electrical energy by radiating the same electromagnetic wave has also been attempted. Our electric toothbrushes and some wireless shavers are actually charged with electromagnetic induction. Electromagnetic induction is a phenomenon in which a voltage is induced and a current flows when a magnetic field is changed around a conductor. The electromagnetic induction method is rapidly commercialized mainly in small-sized devices, but there is a problem in that the transmission distance of electric power is short.

Up to now, the energy transmission method using a wireless method includes a resonance method in addition to electromagnetic induction and a remote transmission technique using a short wavelength radio frequency.

In recent years, resonance-based energy transmission methods have been widely used among such wireless power transmission techniques.

In the wireless power transmission system using resonance, since the electric power is transmitted wirelessly through the coils of the transmission side and the reception side, the user can easily charge the electronic device such as the portable device.

However, there is a problem that a power loss occurs due to a current lost at the receiving side.

Embodiments provide a power generation device that can minimize currents that are wasted or consumed.

The embodiment provides a power generation device capable of improving the wireless power transmission efficiency.

The embodiment provides a wireless power transmission apparatus including the power generation apparatus.

An embodiment provides a wireless power transmission system including the wireless power transmission apparatus.

According to an embodiment, the power generation device includes: an AC power control unit for generating first to fourth AC power control signals; And a DC-AC converting part including a transistor circuit part of a full bridge structure and generating AC power including a positive voltage and a negative voltage in response to the first to fourth AC power control signals. Wherein the DC-AC converting unit generates the positive voltage in response to the first AC power control signal and the fourth AC power control signal, and generates the positive AC voltage in response to the second AC power control signal and the third AC power control signal, Thereby generating a negative voltage.

According to an embodiment, the power generation device includes: an AC power control unit for generating first to fourth AC power control signals in accordance with a PWM (Pulse Width Modulation) control signal; And a DC-AC converting part including a transistor circuit part of a full bridge structure and generating AC power including a positive voltage and a negative voltage in response to the first to fourth AC power control signals. According to an embodiment, a wireless power transmission apparatus includes: the power generation apparatus; A transmitting coil for transmitting power of the power generating device; And a controller for generating a PWM control signal for generating power different from each other from the power generation apparatus according to the state of the wireless power receiving apparatus.

According to an embodiment, a wireless power transmission system comprises: the wireless power transmission device; And a wireless power receiving apparatus that receives the wireless power of the wireless power transmission apparatus and transmits the wireless power to the wireless power transmission apparatus.

The embodiment is characterized by varying the AC power control signal for controlling the AC power generating section according to the reception state of the wireless power receiving apparatus and changing the duty ratio of the AC voltage of the AC power output from the AC power generating section in response to the variation of the AC power control signal The ratio is adjusted to adjust the size of the AC power, thereby preventing the current loss from occurring, thereby preventing power consumption.

Meanwhile, various other effects will be directly or implicitly disclosed in the detailed description according to the embodiments to be described later.

1 is a diagram for explaining a wireless power transmission system according to an embodiment.
2 is an equivalent circuit diagram of a transmission induction coil according to the embodiment.
3 is an equivalent circuit diagram of a power source and a wireless power transmission apparatus according to an embodiment.
4 is an equivalent circuit diagram of a wireless power receiving apparatus according to an embodiment.
5 is a block diagram illustrating a wireless power transmission apparatus according to an embodiment.
6 is a block diagram showing the AC power generation unit of FIG.
7 is a circuit diagram showing the DC-AC converting unit of FIG.
8 is a diagram showing an example of a signal waveform diagram used in the AC power generation unit of FIG.
FIG. 9 is another example of a signal waveform diagram used in the AC power generation unit of FIG. 5; FIG.
FIG. 10 shows the magnitude of AC power output from the AC power generator of FIG. 8 according to frequency components.
FIG. 11 shows the magnitude of the AC power output from the AC power generator of FIG. 9 according to the frequency component.
FIG. 12 shows a current path when the first and fourth transistors are turned on in the DC-AC conversion unit of FIG. 6;
FIG. 13 shows a current path when the second and third transistors are turned on in the DC-AC converting unit of FIG. 6;

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

1 is a diagram for explaining a wireless power transmission system according to an embodiment.

Referring to FIG. 1, a wireless power transmission system according to an embodiment may include a power source 100, a wireless power transmission device 200, a wireless power reception device 300, and an access terminal 400.

In an embodiment, the power source 100 may be included in the wireless power transmission device 200, but is not limited thereto.

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

The wireless power receiving apparatus 300 may include a receiving resonant coil 310, a receiving induction coil 320, and a rectifying unit 330.

Both ends of the power source 100 may be connected to both ends of the transmission induction coil 210.

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

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

Both ends of the reception induction coil 320 can be connected to both ends of the rectification part 330 and the lower end 400 can be connected to both ends of the rectification part 330. In the embodiment, the terminal 400 may be included in the wireless power receiving apparatus 300.

The power generated by the power source 100 is transmitted to the wireless power transmission apparatus 200 and the power transmitted to the wireless power transmission apparatus 200 is resonated with the wireless power transmission apparatus 200, And the resonance frequency values can be transmitted to the same wireless power receiving apparatus 300.

More specifically, the power transmission process will be described below.

The power source 100 may generate and transmit AC power having a predetermined frequency to the wireless power transmission apparatus 200.

The transmission induction coil 210 and the transmission resonance coil 220 may be inductively coupled. That is, in the transmission induction coil 210, an AC current is generated by the AC power supplied from the power source 100, and the transmission resonance coil 220, which is physically spaced apart by the electromagnetic induction by the AC current, Can be induced.

Thereafter, the power transmitted to the transmission resonance coil 220 can be transmitted to the wireless power receiving apparatus 300 having the same resonance frequency by using the frequency resonance method with the wireless power transmission apparatus 200 by resonance.

Power can be transmitted by resonance between two LC circuits whose impedance is matched. Such resonance-based power transmission enables power transmission to be performed at a higher transmission efficiency to a greater extent than the power transmission by the electromagnetic induction method.

The reception resonant coil 310 can receive the electric power transmitted from the transmission resonant coil 220 using the frequency resonance method. An AC current can flow in the reception resonance coil 310 due to the received power and the power transmitted to the reception resonance coil 310 is transmitted to the reception induction coil 320 inductively coupled to the reception resonance coil 310 by electromagnetic induction, Lt; / RTI > The power transmitted to the reception induction coil 320 may be rectified through the rectifying unit 330 and transmitted to the loading stage 400.

The transmission resonance coil 220, the reception resonance coil 310 and the reception induction coil 320 may have any one of a spiral structure and a helical structure, , But need not be limited thereto.

The transmitting resonant coil 220 and the receiving resonant coil 310 may be resonantly coupled so as to transmit electric power at a resonant frequency.

The power transmission efficiency between the wireless power transmission apparatus 200 and the wireless power reception apparatus 300 can be greatly improved due to the resonance coupling between the transmission resonance coil 220 and the reception resonance coil 310.

The above-mentioned wireless power transmission system explained the power transmission by the resonance frequency method.

The embodiment can be applied to power transmission by an electromagnetic induction method in addition to the resonance frequency method.

That is, in the embodiment, when the wireless power transmission system performs power transmission based on the electromagnetic induction, the transmission resonance coil 220 included in the wireless power transmission apparatus 200 and the reception The resonance coil 310 can be omitted.

In wireless power transmission, quality factor and coupling coefficient can have important meaning. That is, the power transmission efficiency can be proportional to the quality index and the coupling coefficient, respectively. Therefore, as the value of at least one of the quality index and the coupling coefficient increases, the power transmission efficiency can be improved.

The quality factor may mean an index of energy that can be accumulated in the vicinity of the wireless power transmission apparatus 200 or the wireless power reception apparatus 300.

The quality factor may vary depending on the operating frequency (w), the shape of the coil, the dimensions, and the material. The quality index can be expressed by the following equation (1).

[Formula 1]

Q = w * L / R

L is the inductance of the coil, and R is the resistance corresponding to the amount of power loss occurring in the coil itself.

The quality factor can have a value from 0 to infinity. The larger the quality index, the higher the power transmission efficiency between the wireless power transmission apparatus 200 and the wireless power reception apparatus 300 can be.

Coupling coefficient means the degree of magnetic coupling between the transmitting coil and the receiving coil, and ranges from 0 to 1.

The coupling coefficient may vary depending on the relative position or distance between the transmitting coil and the receiving coil.

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

As shown in FIG. 2, the transmission induction coil 210 may be constituted by an inductor L 1 and a capacitor C 1, thereby constituting a circuit having a proper inductance and a capacitance value.

The transmission induction coil 210 may be constituted by an equivalent circuit in which both ends of the inductor L1 are connected to both ends of the capacitor C1. That is, the transmission induction coil 210 may be composed of 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 the impedance matching may be performed as the capacitance of the capacitor C1 is adjusted. The equivalent circuits of the transmission resonant coil 220, the reception resonant coil 310, and the reception induction coil 320 may also be the same as or similar to those shown in FIG. 2, but the invention is not limited thereto.

3 is an equivalent circuit diagram of a power source and a wireless power transmission apparatus according to an embodiment.

3, the transmission induction coil 210 and the transmission resonance coil 220 may include inductors L1 and L2 and capacitors C1 and C2 having inductance and capacitance values, respectively.

4 is an equivalent circuit diagram of a wireless power receiving apparatus according to an embodiment.

4, the reception resonant coil 310 and the reception induction coil 320 may include inductors L3 and L4 and capacitors C3 and C4 having inductance and capacitance values, respectively.

The rectifying unit 330 may convert the AC power received from the reception induction coil 320 into DC power and transmit the converted DC power to the loading stage 400.

Specifically, the rectification section 330 may include a rectifier and a smoothing circuit although not shown. In the embodiment, the rectifier may be a silicon rectifier, and may be equivalent to diode D1, as shown in FIG. 4, but this is not limiting.

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

The smoothing circuit can output smooth DC power by removing the AC component included in the DC power converted in the rectifier. In the embodiment, as the smoothing circuit, as shown in Fig. 4, a rectifying capacitor C5 may be used, but it need not be limited thereto.

The DC power delivered from the rectifying unit 330 may be a DC voltage or a DC current, but the present invention is not limited thereto.

The lower stage 400 may be any rechargeable battery or device requiring direct current power. For example, the lower stage 400 may mean a battery.

The wireless power receiving apparatus 300 may be mounted on an electronic apparatus requiring power such as a mobile phone, a notebook computer, and a mouse. Accordingly, the reception resonant coil 310 and the reception induction coil 320 may have shapes conforming to the shape of the electronic device.

The wireless power transmission apparatus 200 can exchange information with the wireless power reception apparatus 300 using in-band or out-of-band communication.

In band communication may refer to a communication in which information is exchanged between a wireless power transmission apparatus 200 and a wireless power reception apparatus 300 using a signal having a frequency used for wireless power transmission. To this end, the wireless power receiving apparatus 300 may further include a switch and may not receive or receive the power transmitted from the wireless power transmitting apparatus 200 through the switching operation of the switch. Accordingly, the wireless power transmission apparatus 200 can detect the amount of power consumed in the wireless power transmission apparatus 200 and recognize the ON or OFF signal of the switch included in the wireless power reception apparatus 300. [

Specifically, the wireless power receiving apparatus 300 can change the amount of power consumed in the wireless power transmission apparatus 200 by changing the amount of power absorbed in the resistance by using the resistance element and the switch. The wireless power transmission apparatus 200 can detect the change in the consumed power and acquire the status information of the lower stage 400. [ The switch and the resistive element can be connected in series. In the embodiment, the state information of the loading stage 400 may include information on the current loading amount and the charging amount variation of the loading stage 400. [ The lower stage 400 may be included in the wireless power receiving apparatus 300.

More specifically, when the switch is opened, the power absorbed by the resistance element becomes zero, and the power consumed by the wireless power transmission apparatus 200 also decreases.

When the switch is short-circuited, the power absorbed by the resistance element becomes larger than 0, and the power consumed by the wireless power transmission apparatus 200 increases. When the wireless power receiving apparatus 200 repeats this operation, the wireless power transmitting apparatus 200 can detect the power consumed in the wireless power transmitting apparatus 200 and perform digital communication with the wireless power receiving apparatus 300.

The wireless power transmission apparatus 200 can receive the state information of the lower stage 400 according to the above operation and transmit appropriate power thereto.

Conversely, it is also possible to transmit the status information of the wireless power transmission apparatus 200 to the wireless power reception apparatus 300 by providing a resistance element and a switch on the wireless power transmission apparatus 200 side. The state information of the wireless power transmission apparatus 200 in the embodiment may include the maximum amount of power that can be transmitted by the wireless power transmission apparatus 200, the maximum power amount of the wireless power transmission apparatus 200 that the wireless power transmission apparatus 200 is providing power And information on 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 communication in which information necessary for power transmission is exchanged by using a separate frequency band instead of the resonance frequency band. An out-of-band communication module is installed in each of the wireless power transmission apparatus 200 and the wireless power reception apparatus 300 so that information necessary for power transmission can be exchanged between them. The out-of-band communication module may be mounted on the power source 100, but the invention is not limited thereto. In the embodiment, the out-of-band communication module may use a short-range communication method such as Bluetooth, Zigbee, wireless LAN, or NFC (Near Field Communication), but the present invention is not limited thereto.

5 is a block diagram illustrating a wireless power transmission apparatus according to an embodiment.

1 and 5, a wireless power transmission apparatus 200 according to an embodiment may include an oscillator 230, an AC power generation unit 240, a control unit 235, and a transmission coil 205.

The oscillator 230 may generate an AC signal of a sinusoidal wave. The AC signal can have multiple cycles. One cycle may include a first half period and a second half period. For example, the AC signal of the first half cycle may have a positive sinusoidal wave. For example, the AC signal of the second half-cycle may have a sine wave of negative polarity.

In other words, the alternating signal may be a periodically repeated signal with one cycle of a positive sine wave and a negative sine wave.

The AC signal of the oscillator 230 may be supplied to the AC power generation unit 240.

The AC power generation unit 240 can generate AC power from the power of the power source 100 based on the AC signal of the oscillator 230.

The transmission coil 205 may be a combination of the transmission induction coil 210 and the transmission resonance coil 220 or may be the transmission resonance coil 220 alone. That is, as shown in FIG. 1, the transmission coil 205 may include a transmission induction coil 210 and a transmission resonance coil 220 in the case of an electric device induction system. The transmission coil 205 may be a transmission resonance coil 220 in the case of a resonance type.

The transmission coil 205 can transmit the AC power of the AC power generation unit 240 to the wireless power reception apparatus 300. [

The control unit 235 can control the wireless power transmission apparatus 200 as a whole. The control unit 235 can control the AC power generation unit 240.

The control unit 235 can control the AC power generation unit 240 according to the state of the wireless power receiving apparatus 300, that is, the charging state or the receiving state. For example, when higher radio power is required for the wireless power receiving apparatus 300, the control unit 235 controls the AC power generating unit 240 to generate and transmit higher radio power to the wireless power receiving apparatus 300 can do. For example, when lower wireless power is required for the wireless power receiving apparatus 300, the controller 235 controls the AC power generating unit 240 to generate lower wireless power to be transmitted to the wireless power receiving apparatus 300 can do.

The status of the wireless power receiving apparatus 300 may be provided from the wireless power receiving apparatus 300 in response to a request of the wireless power transmitting apparatus 200. [ Or the status information of the wireless power receiving apparatus 300 from the wireless power receiving apparatus 300 may be provided to the wireless power transmitting apparatus 200 at random or at predetermined time intervals.

The control unit 235 may supply the AC power generation unit 240 with the PWM control signal adjusted in accordance with the state of the wireless power receiving apparatus 300 based on the state information provided from the wireless power receiving apparatus 300. [

For example, the PWM control signal may be 6-bit binary data. For example, when the PWM control signal is 000001, the AC power generation section 240 can generate AC power having an AC voltage with a duty ratio of 50% in response to the PWM control signal. The AC power having the AC voltage having the duty ratio of 50% may be the maximum AC power that can be transmitted to the wireless power receiving apparatus 300, but the present invention is not limited thereto.

For example, when the PWM control signal is 000010, the AC power generation section 240 can generate AC power having an AC voltage with a duty ratio of 40% in response to the control signal.

For example, when the PWM control signal is 000011, the AC power generation section 240 can generate AC power having an AC voltage with a duty ratio of 30% in response to the control signal.

For example, when the PWM control signal is 000100, the AC power generation section 240 can generate AC power having an AC voltage having a duty ratio of 20% in response to the control signal.

For example, when the PWM control signal is 000101, the AC power generation section 240 can generate AC power having an AC voltage having a duty ratio of 10% in response to the control signal.

In addition, by setting 6-bit binary data of the PWM control signal, AC power having an AC voltage in units of 5% duty ratio, 3% duty ratio, or 2% duty ratio may be generated, but this is not restrictive .

The smaller the duty ratio, the smaller the AC power can be.

Thus, instead of adjusting the magnitude of the power of the power source 100 to regulate the alternating current power for transmission to the wireless power receiving apparatus 300, the embodiment may adjust the control signal used to generate the alternating current power, By varying the size, current loss is not generated, and power consumption is also cut off, thereby improving power transmission efficiency.

The AC power generating unit 240 may generate AC power to be transmitted to the wireless power receiving apparatus 300 based on the power supplied from the power source 100.

The AC power generating unit 240 may generate AC power reflecting the state of the wireless power receiving apparatus 300 under the control of the controller 235.

The AC power generation unit 240 may convert the power provided from the power source 100 into AC power.

AC power generation section 240 can amplify the power supplied from power source 100. [

The AC power generation unit 240 may convert the power provided from the power source 100 into AC power, and then amplify the converted AC power.

Although the AC power generation unit 240 is included in the wireless power transmission apparatus 200 in the drawing, the AC power generation unit 240 may be provided separately from the wireless power transmission apparatus 200. Alternatively, the AC power generation unit 240 may be included in the power source 100, but the present invention is not limited thereto.

6 is a block diagram showing the AC power generation unit of FIG.

Referring to FIG. 6, the AC power generation unit 240 may include an AC power control unit 242 and a DC-AC conversion unit 244.

Although not shown, the AC power generating unit 240 may further include a DC-DC converting unit, but the present invention is not limited thereto. The DC-DC converter may convert the power of the power source 100 into DC power having a DC voltage and provide DC power to the DC-AC converter 244.

The output voltage of the DC-DC converting section may be, for example, a DC voltage of 12 V, but it is not limited thereto.

If a DC voltage of 12V is output from the power source 100, the DC-DC converter may be omitted.

The DC-AC converting portion 244 may include a transistor circuit portion of a full-bridge structure, as shown in FIG.

For example, the transistor circuit portion of the full bridge structure may include the first to fourth transistors T11, T12, T21, and T22.

For example, the first transistor T11 and the second transistor T12 may be connected in series between the fifth node n5 and the ground terminal. In addition, for example, the third transistor T21 and the fourth transistor T22 may be connected in series between the fifth node n5 and the ground terminal.

The first transistor T11 and the third transistor T21 may be connected in parallel to the fifth node n5 and the second transistor T12 and the fourth transistor T22 may be connected in parallel to the ground terminal.

The fifth node n5 may be connected to the power source 100 or the DC-DC converter.

The first to fourth transistors T11, T12, T21 and T22 may be an N-type MOSFET (Metal-Oxide-Semiconductor Field-Effect-Transistor), but the invention is not limited thereto.

The first transistor T11 may be connected to the first node n1, the fifth node n5, and the sixth node n6. That is, the gate terminal of the first transistor T11 may be connected to the first node n1, the source terminal may be connected to the fifth node n5, and the drain terminal may be connected to the sixth node n6.

The second transistor T12 may be connected to the second node n2, the sixth node n6, and the ground terminal. That is, the gate terminal of the second transistor T12 may be connected to the second node n2, the source terminal may be connected to the sixth node n6, and the drain terminal may be connected to the ground terminal.

The third transistor T21 may be connected to the third node n3, the fifth node n5, and the seventh node n7. That is, the gate terminal of the third transistor T21 may be connected to the third node n3, the source terminal may be connected to the fifth node n5, and the drain terminal may be connected to the seventh node n7.

The fourth transistor T22 may be connected to the fourth node n4, the seventh node n7, and the ground terminal. That is, the gate terminal of the fourth transistor T22 may be connected to the fourth node n4, the source terminal thereof may be connected to the seventh node n7, and the drain terminal may be connected to the ground terminal.

The first to fourth nodes n1, n2, n3, and n4 may be output terminals of the AC power control unit 242. The AC power control unit 242 may generate the first to fourth AC power control signals C11, C12, C21, and C22. For example, the first AC power control signal C11 may be output to the first node n1, and the second AC power control signal C12 may be output to the second node n2. For example, the third AC power control signal C21 may be output to the third node n3 and the fourth AC power control signal C22 may be output to the fourth node n4.

The sixth node n6 is an output terminal of the first transistor T11 or the second transistor T12 and the seventh node n7 is an output terminal of the third transistor T21 or the fourth transistor T22. have.

The first transistor T11 may be opened when the first AC power control signal C11 is at a high level and open when the first AC power control signal C11 is at a low level. The second transistor T12 may be opened when the second AC power control signal C12 is at a high level and open when the second AC power control signal C12 is at a low level.

The third transistor T21 may be opened when the third AC power control signal C21 is at a high level and open when the third AC power control signal C21 is at a low level. The fourth transistor T22 may be turned on when the fourth AC power control signal C22 is at a high level and open when the fourth AC power control signal C22 is at a low level.

The first to fourth AC power control signals C11, C12, C21, and C22 may be changed according to the PWM control signal provided from the controller 235, as shown in FIGS. The rising times Tr11, Tr12, Tr21 and Tr22 of the first to fourth AC power control signals C11, C12, C21 and C22 and the polling times Tf11, Tf12, Tf21 and Tf22 may be different have. The conduction time of the first to fourth transistors T11, T12, T21 and T22 is changed in response to the first to fourth AC power control signals C11, C12, C21 and C22, The duty ratio Ton of the AC voltage Vout of the AC power supplied to the AC power source 205 may be varied.

The embodiment may be configured to vary the duty ratio Ton of the AC voltage Vout of the AC power according to the state of the wireless power receiving apparatus 300 such as the charging state and / Can be received.

In addition, the embodiment can cut the current that may be lost in generating AC power in the wireless power transmission apparatus 200, thereby minimizing power consumption.

FIG. 8 shows waveform diagrams of first to fourth AC power control signals generated by a PWM control signal for generating AC power having an AC voltage having a duty ratio of 50%.

As shown in FIG. 8, the first to fourth AC power control signals C11, C12, C21, and C22 may be generated based on the clock signal Clock.

The clock signal Clock may be generated on the basis of the AC signal of the oscillator 230 or may be generated by a separate means, but it is not limited thereto.

The clock signal Clock can be generated by repeating a high-level pulse and a low-level pulse in one cycle.

For example, the first AC power control signal C11 defines a rising time Tr11 for a high level at a time delayed by a predetermined time from a rising time of a first high level pulse in the clock signal (Clock) A falling time Tf11 for a low level in the rising time of the second high level pulse may be defined.

For example, the high level section of the second AC power control signal C12 does not overlap the high level section of the first AC power control signal C11. If the high level section of the first AC power control signal C11 overlaps the high level section of the second AC power control signal C12, the first transistor T11 and the second transistor T12 are simultaneously turned on The output voltage of the power source 100 or the DC-DC converter is discharged to the ground terminal, and the output voltage of the power source 100 or the DC-DC converter is not applied to the sixth node n6, The power is not transmitted. The rising time Tr11 of the first AC power control signal C11 or the rising time Tr12 of the second AC power control signal C12 or the rising time Tr11 of the first AC power control signal C11, A blank interval T _{PA in} which no high level interval of the first and second AC power control signals C11 and C12 is present between the first AC power control signal C12 and the polling time Tf12 of the second AC power control signal C12, Can be defined.

The second AC power control signal C12 has a rising time Tr12 defined for a high level at a time delayed from the rising time of the second high level in the clock signal Clock by a predetermined time, A polling time Tf12 for a low level in time can be defined.

For example, the high level period of the third AC power control signal C21 partially overlaps the high level period of the first AC power control signal C11 and partially overlaps the high level period of the second AC power control signal C12 . That is, the rising time Tr21 of the third AC power control signal C21 is faster than the polling time Tf11 of the first AC power control signal C11 and is shorter than the polling time Tf21 of the third AC power control signal C21. Is later than the rising time Tr12 of the second AC power control signal C12.

For example, the high level section of the fourth AC power control signal C22 does not overlap the high level section of the third AC power control signal C21. Likewise, if the high level section of the third AC power control signal C21 overlaps the high level section of the fourth AC power control signal C22, the third transistor T21 and the fourth transistor T22 simultaneously The output voltage of the power source 100 or the DC-DC converting unit is discharged to the ground terminal, and the output voltage of the power source 100 or the DC-DC converting unit is not applied to the seventh node n7, The electric power is not transmitted to the antenna 205. The rising time Tr21 of the third AC power control signal C21 or the rising time Tr22 of the fourth AC power control signal C22 or the rising time Tr22 of the third AC power control signal C21, A blank interval T _{AP in} which there is no high level section of the third and fourth AC power control signals C21 and C22 between the polling time Tf22 of the fourth AC power control signal C22 and the polling time Tf22 of the fourth AC power control signal C22, Can be defined.

The high level section of the fourth AC power control signal C22 partially overlaps the high level section of the first AC power control signal C11 and partially overlaps the high level section of the second AC power control signal C12 . That is to say, the rising time Tr22 of the fourth AC power control signal C22 is faster than the polling time Tf12 of the second AC power control signal C12 and the rising time Tr11 of the first AC power control signal C11, It is later.

A high level interval of each of the first to fourth AC power control signals C11, C12, C21, and C22 may be defined within one period of the clock signal Clock.

The polling time Tf21 of the third AC power control signal C21 and the polling time Tf22 of the fourth AC power control signal C22 may be adjusted according to the binary data value of the PWM control signal provided from the control unit 235 .

12, alternating-current power having a positive polarity voltage may be supplied to the transmission coil 205 while the first transistor T11 and the fourth transistor T22 are conducting.

The first AC power control signal C11 is applied to the first transistor T11 via the first node n1 and the fourth AC power control signal C22 is applied to the fourth transistor n14 via the fourth node n4, (T22).

The rising time Tr11 of the first AC power control signal C11 is overlapped with the fourth AC power control signal C22 and this overlap ends at the polling time Tf22 of the fourth AC power control signal C22 . Therefore, the high level of the first AC power control signal C11 from the rising time Tr11 of the first AC power control signal C11 to the polling time Tf22 of the fourth AC power control signal C22, The high level of the power control signal C22 may overlap. The first transistor T11 and the fourth transistor T22 are electrically connected to each other while the high level of the first and fourth AC power control signals C11 and C22 is overlapped with each other and the power source 100 and the DC- A current path is formed to the ground terminal via the fifth node n5, the first transistor T11, the sixth node n6, the transmission coil 205, the seventh node n7 and the fourth transistor T22 So that the positive polarity voltage can be supplied to the transmission coil 205. Meanwhile, the polling time Tf22 of the fourth AC power control signal C22 may precede the polling time Tf11 of the first AC power control signal C11. Therefore, since at least the fourth transistor T22 is open during the period between the polling time Tf22 of the fourth AC power control signal C22 and the polling time Tf11 of the first AC power control signal C11, The fifth node n5, the first transistor T11, the sixth node n6, the transmission coil 205, the seventh node n7 and the fourth transistor T22 from the source 100 or the DC- The current path is not formed at the ground terminal and the positive voltage is not supplied to the transmission coil 205. [

The high-level overlap period of the first and fourth AC power control signals C11 and C22 may be defined as a duty ratio Ton as a power transfer period. The duty ratio Ton can be set to a maximum of 50% as an electric power transferable period for one period, but the present invention is not limited thereto. For example, in the case of a duty ratio (Ton) of 50%, half of one cycle is capable of power transfer and the other half of one cycle is not capable of power transfer.

13, AC power having a negative voltage may be supplied to the transmission coil 205 while the second transistor T12 and the third transistor T21 are conducting.

The second AC power control signal C12 is applied to the second transistor T12 via the second node n2 and the third AC power control signal C21 is applied to the third node n3 via the third node n3, And may be applied to the transistor T21.

Is overlapped with the third AC power control signal C21 from the rising time Tr12 of the second AC power control signal C12 and this overlap ends at the polling time Tf21 of the third AC power control signal C21 The high level of the second AC power control signal C12 from the rising time Tr12 of the second AC power control signal C12 to the polling time Tf21 of the third AC power control signal C21, The high level of the three AC power control signal C21 may overlap. The second transistor T12 and the third transistor T21 are turned on while the high level of the second and third AC power control signals C21 overlap with each other and the fifth transistor T12 and the third transistor T21 from the power source 100 and the DC- A current path is formed to the ground terminal via the node n5, the third transistor T21, the seventh node n7, the transmission coil 205, the sixth node n6 and the second transistor T12, A negative voltage may be applied to the transmission coil 205. [ Meanwhile, the polling time Tf21 of the third AC power control signal C21 may precede the polling time Tf12 of the second AC power control signal C12. Therefore, at least the third transistor T21 is opened during the period between the polling time Tf21 of the third AC power control signal C21 and the polling time Tf12 of the second AC power control signal C12, A third transistor T21, a seventh node n7, a transmission coil 205, a sixth node n6 and a second transistor T12 from the source 100 or the DC- The current path is not formed at the ground terminal, so that the negative voltage is not supplied to the transmission coil 205.

The high-level overlap period of the second and third AC power control signals C12 and C21 may be defined as a duty ratio Ton as a power transfer period.

It can be seen from Fig. 8 that the duty ratio Ton is determined by the polling time Tf21 of the third AC power control signal C21 and the polling time Tf22 of the fourth AC power control signal C22. When the polling time Tf22 is delayed, the duty ratio Ton is increased and when the polling time Tf22 is increased, the duty ratio Ton can be reduced.

When the duty ratio Ton is increased, the AC power transmitted to the transmission coil 205 is increased, so that the wireless power received by the wireless power receiving apparatus 300 can also be increased. When the duty ratio Ton is reduced, the AC power transmitted to the transmitting coil 205 is reduced, so that the wireless power received by the wireless power receiving apparatus 300 can also be reduced.

The first to fourth AC power control signals C11, C12, C21, and C21 in the AC power control unit 242 in accordance with the PWM control signal reflecting the increase or decrease of the AC power to be transmitted to the wireless power receiving apparatus 300, And the duty ratio Ton of the AC voltage Vout output from the DC-AC converting portion 244 by the first to fourth AC power control signals C11, C12, C21, and C22 is And the radio power having the thus adjusted AC voltage Vout of the duty ratio Ton can be transmitted to the wireless power receiving apparatus 300 by the transmitting coil 205. [

FIG. 9 shows waveform diagrams of first to fourth AC power control signals generated by a PWM control signal for generating AC power having an AC voltage having a duty ratio of 30%.

9, the method of generating the first to fourth AC power control signals C11, C12, C21, and C22 is the same as the above description related to Fig.

The AC voltage Vout shown in FIG. 9 has a duty ratio Ton of 30%, which is smaller than the duty ratio Ton of 50% of the AC voltage Vout shown in FIG. In other words, the width of the positive or negative voltage with a duty ratio (Ton) of 30% may be less than the width of the positive or negative voltage having a duty ratio (Ton) of 50%.

Thus, the first to fourth AC power control signals C11, C12, C21, and C22 may be varied so that the duty ratio of the AC voltage Vout is reduced to 30%. That is, the polling time Tf12 of the second AC power control signal C12 and the polling time Tf21 of the third AC power control signal C21 shown in Fig. 9 are the second AC power control signal The polling time Tf12 of the third AC power control signal C12 and the polling time Tf21 of the third AC power control signal C21.

Therefore, as the duty ratio Ton of the AC voltage Vout decreases, the polling time Tf12 of the second AC power control signal C12 and the polling time Tf21 of the third AC power control signal C21 are advanced Can be. For example, the polling time Tf12 of the second AC power control signal C12 and the polling time Tf21 of the third AC power control signal C21 at a duty ratio Ton of 20% rather than a duty ratio Ton of 30% ) Can be made earlier.

FIG. 10 shows the magnitude of AC power having an AC voltage of 50% duty ratio in FIG. 8, and FIG. 11 is a graph showing a magnitude of a frequency component of an AC power having an AC voltage of 30% .

10 and 11 are experimental data using a simulation technique, and the maximum value of the voltage is 1 V, but the magnitude of the wireless power actually used for power transmission may be 12 V, for example.

As shown in FIGS. 10 and 11, a voltage may be generated from a fundamental frequency component and a plurality of harmonic frequency components that are multiples of the fundamental frequency component. Of these, the voltage at the harmonic frequency component makes no contribution to the power to be transmitted to the wireless power receiving apparatus 300.

As shown in Fig. 10, when the duty ratio (Ton) is 50%, the voltage magnitude at the fundamental frequency is 0.64V.

On the other hand, as shown in Fig. 11, when the duty ratio (Ton) is 30%, the voltage magnitude at the fundamental frequency is 0.51V.

Therefore, it can be seen that as the duty ratio Ton decreases, the voltage magnitude at the fundamental frequency decreases. As the voltage magnitude decreases, the power to be transmitted to the wireless power receiving apparatus 300 can also be reduced.

The method according to the above-described embodiments may be implemented as a program to be executed by a computer and stored in a computer-readable recording medium. Examples of the computer-readable recording medium include a ROM, a RAM, a CD- , A floppy disk, an optical data storage device, and the like, and may also be implemented in the form of a carrier wave (for example, transmission over the Internet).

The computer readable recording medium may be distributed over a networked computer system so that computer readable code can be stored and executed in a distributed manner. And, functional program, code, and code segments for implementing the above-described method can be easily inferred by programmers in the technical field to which the embodiment belongs.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It should be understood that various modifications may be made by those skilled in the art without departing from the spirit and scope of the present invention.

The wireless power receiving apparatus 300 according to the exemplary embodiment of the present invention can be applied to a portable device such as a mobile phone, a smart phone, a laptop computer, a digital broadcasting terminal, a PDA (Personal Digital Assistants), a portable multimedia player (PMP) And can be mounted on the terminal.

However, it will be readily apparent to those skilled in the art that the configuration according to the embodiment may be applied to a fixed terminal such as a digital TV, a desktop computer, and the like, except when it is applicable only to a mobile terminal.

In the embodiment, the method of transmitting electric power by electromagnetic induction has a relatively low Q value and means tightly coupling, and a method of transmitting power by resonance has a relatively high Q value, May be referred to as loosely coupling.

100: Power source
200: Wireless power transmitting device
205: transmission coil
210: transmission induction coil
220: transmission resonance coil
230: Oscillator
235:
240: AC power generating unit
242: AC power control unit
244: DC-AC conversion unit
300: Wireless power receiving device
310: Receive resonant coil
320: reception induction coil
330: rectification part
400:
n1, n2, n3, n4, n5, n6, n7:
T11, T12, T21, T22: transistors
Tr11, Tr12, Tr21, Tr22: Rising time
Tf11, Tf12, Tf21, Tf22: Polling time

Claims (13)

A power generation apparatus for generating power for transmission to a wireless power receiving apparatus,
An AC power control unit for generating first to fourth AC power control signals; And
And a DC-AC converting unit for generating AC power including a positive voltage and a negative voltage in response to the first to fourth AC power control signals,
Wherein the DC-AC converting unit generates the positive voltage in response to the first AC power control signal and the fourth AC power control signal, and generates the positive AC voltage in response to the second AC power control signal and the third AC power control signal, A power generation device for generating a negative voltage. The method according to claim 1,
The first to fourth AC power control signals are generated according to a PWM control signal,
The duty ratio of the positive voltage is determined by the polling time of the fourth AC power control signal,
Wherein the duty ratio of the negative voltage is determined by a polling time of the third AC power control signal. A power generation apparatus for generating power for transmission to a wireless power receiving apparatus,
An AC power control unit for generating first to fourth AC power control signals according to a PWM control signal; And
And a DC-AC converting unit for generating AC power including a positive voltage and a negative voltage in response to the first to fourth AC power control signals. The method of claim 3,
Wherein the PWM control signal is binary data reflecting a magnitude of power adjusted according to a state of the wireless power receiving apparatus. The method of claim 3,
Wherein the poling time of each of the third AC power control signal and the fourth AC power control signal is adjusted according to the PWM control signal so that the duties of the positive voltage and the negative voltage are different. The method according to claim 1 or 3,
The direct current-to-
A first transistor coupled to the first node, the fifth node, and the sixth node and rendered conductive in response to the first AC power control signal of the first node to supply the voltage of the fifth node to the sixth node;
A second transistor connected to the second node, the sixth node and the ground terminal and rendered conductive in response to the second AC power control signal of the second node to supply the voltage of the sixth node to the ground terminal;
A third transistor coupled to the third node, the fifth node and the seventh node and rendered conductive in response to the third AC power control signal of the third node and supplying the voltage of the fifth node to the seventh node; ; And
A fourth transistor coupled to the fourth node, the seventh node, and the ground terminal and rendered conductive in response to the fourth AC power control signal of the fourth node to supply a voltage of the seventh node to the ground terminal, Power generating device. The method according to claim 1 or 3,
Wherein the polling time of the fourth AC power control signal is ahead of the polling time of the first AC power control signal. The method according to claim 1 or 3,
Wherein the polling time of the third AC power control signal is ahead of the polling time of the second AC power control signal. The method according to claim 1,
When the duty ratio is 50%, maximum AC power is generated,
And the magnitude of the AC power is reduced when the duty ratio is reduced. The method of claim 3,
The state of the wireless power receiving apparatus is a charging state or a receiving state,
Wherein the binary data value of the PWM control signal varies according to a state of the wireless power receiving apparatus. 11. The method of claim 10,
And the polling time of each of the third AC power control signal and the fourth AC power control signal is adjusted according to the binary data value. A wireless power transmission apparatus for transmitting wireless power to a wireless power receiving apparatus,
A power generation device according to claim 2 or 3;
A transmitting coil for transmitting power of the power generating device; And
And a controller for generating a PWM control signal for generating power different from each other from the power generation apparatus according to the state of the wireless power receiving apparatus. A wireless power transmission apparatus according to claim 12, which generates wireless power; And
And a wireless power receiving apparatus for receiving the wireless power of the wireless power transmission apparatus and delivering the wireless power to a lower stage.

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