KR102252469B1 - Wireless power transmission apparatus and wireless power transmission method - Google Patents

Abstract

It relates to an apparatus and method for wirelessly transmitting power, in one aspect, wherein the wireless power transmission apparatus wirelessly transmits power through magnetic coupling between a plurality of source resonators and a target resonator, and the plurality of source resonators At least one of a voltage intensity and a current intensity of power supplied to a feeding unit that supplies power to the fields may be controlled.

Description

Wireless power transmission device and wireless power transmission method {WIRELESS POWER TRANSMISSION APPARATUS AND WIRELESS POWER TRANSMISSION METHOD}

The following embodiments relate to an apparatus and method for wirelessly transmitting power.

Research on wireless power transmission was initiated to overcome the increased inconvenience of wired power supply due to the explosive increase of various electric devices including electric vehicles and portable devices, and the limitations of existing battery capacity. One of the wireless power transmission technologies uses the resonance (resonance) characteristics of RF elements. The wireless power transmission system using the resonance characteristic may include a source supplying power and a target receiving power.

A wireless power transmission device according to one side includes a plurality of resonators for wirelessly transmitting first power to the wireless power reception device; A controller for controlling at least one of a voltage magnitude and a current magnitude of the second power supplied to the at least one resonator; And a feeding part supplying the second power to the at least one resonator. The control unit, in a wireless charging area of the wireless power transmission device, obtains at least one of a distance, a direction, and an angle between the wireless power transmission device and the wireless power reception device, and receives the wireless power transmission device and the wireless power. At least one of the voltage intensity and the current intensity of the second power may be adjusted based on at least one of the distance, the direction, and the angle between devices.

The control unit obtains the number of wireless power receiving devices to be charged in the wireless charging area, and further determines at least one of the voltage strength and the current strength of the second power based on the number of wireless power receiving devices to be charged. Can be adjusted.

The control unit acquires information on a position change of the wireless power receiving device in the wireless charging area, and further based on the information on the position change of the wireless power receiving device, the voltage strength and the current strength of the second power At least one of them can be adjusted.

The controller calculates an impedance of the N port network between the resonators connected to the N port network and other resonators connected to the N port network, and further based on the impedance, the voltage strength and the current strength of the second power You can control at least one of them.

The resonators may be coupled to each other or separated from each other, and the feeding part may include an inductor.

The control unit may sequentially change at least one of the voltage intensity and the current intensity of the second power within at least one of the voltage intensity and the current intensity that can be applied by the feeding unit.

The controller may randomly change at least one of the voltage intensity and the current intensity of the second power within at least one of the voltage intensity and the current intensity that can be applied by the feeding part.

The controller may change at least one of the voltage intensity and the current intensity of the second power based on a lookup table within at least one of the voltage intensity and the current intensity that can be applied by the feeding part.

Each of the resonators includes a first transmission line including a first signal conductor portion, a second signal conductor portion, and a first ground conductor portion corresponding to the first signal conductor portion and the second signal conductor portion; A first conductor connecting the first signal conductor portion and the first ground conductor portion; A second conductor connected to the second signal conductor portion; And a first capacitor inserted between the first signal conductor portion and the second signal conductor portion in series with respect to a current flowing through the first signal conductor portion and the second signal conductor portion.

The resonators include a first resonator including a plane parallel to the xy plane; a second resonator including a plane parallel to the yz plane; And a third resonator including a plane parallel to the zx plane.

A wireless power transmission device according to one side includes a plurality of resonators for transmitting first power to the wireless power reception device; A controller for controlling at least one of a voltage phase and a current phase of the second power supplied to the at least one resonator; And a feeding part supplying the second power to the at least one resonator. The control unit, in a wireless charging area of the wireless power transmission device, obtains at least one of a distance, a direction, and an angle between the wireless power transmission device and the wireless power reception device, and receives the wireless power transmission device and the wireless power. At least one of the voltage phase and the current phase of the second power may be adjusted based on at least one of the distance, the direction, and the angle between devices.

The control unit obtains the number of wireless power receiving devices to be charged in the wireless charging area, and further determines at least one of the voltage phase and the current phase of the second power based on the number of wireless power receiving devices to be charged. Can be adjusted.

The control unit acquires information on a position change of the wireless power receiving device in the wireless charging area, and further based on the information on the position change of the wireless power receiving device, the voltage phase and the current phase of the second power At least one of them can be adjusted.

The controller calculates an impedance of the N port network between the resonators connected to the N port network and other resonators connected to the N port network, and further based on the impedance, the voltage phase and the current of the second power At least one of the phases can be controlled.

The resonators include a first resonator including a plane parallel to the xy plane; a second resonator including a plane parallel to the yz plane; And a third resonator including a plane parallel to the zx plane.

A method of operating a wireless power transmission device comprising a plurality of resonators for wirelessly transmitting first power to the wireless power receiving device according to one side and a feeding unit for supplying second power to at least one resonator, the at least one resonator And controlling at least one of a voltage intensity, a voltage phase, a current intensity, and a current phase of the second power supplied to the device. The controlling may include obtaining at least one of a distance, a direction, and an angle between the wireless power transmitter and the wireless power receiver in a wireless charging area of the wireless power transmitter; And at least one of the voltage intensity, the voltage phase, the current intensity, and the current phase of the second power based on at least one of the distance, the direction, and the angle between the wireless power transmitter and the wireless power receiver. And adjusting one.

The controlling step further includes obtaining the number of wireless power receiving devices to be charged in the wireless charging area, and the adjusting step is further based on the number of wireless power receiving devices to be charged in the wireless charging area. It may include adjusting at least one of the voltage intensity and the current intensity of the second power.

The controlling step further includes acquiring information on a position change of the wireless power receiving device in the wireless charging area, and the adjusting step is further based on the information on the position change of the wireless power receiving device. It may include adjusting at least one of the voltage intensity and the current intensity of the second power.

The controlling step further includes calculating an impedance of the N-port network between the resonators connected to the N-port network and another resonator connected to the N-port network, and the adjusting is further based on the impedance. It may include adjusting at least one of the voltage intensity and the current intensity of the second power.

1 shows a wireless power transmission system according to an embodiment.
2 shows a wireless charging environment in which a wireless power transmission device according to an embodiment can be used.
3 is a block diagram of an apparatus for transmitting power wirelessly according to an exemplary embodiment.
4 is a block diagram of an apparatus for transmitting power wirelessly according to another exemplary embodiment.
5 shows an N port network of a wireless power transmission device according to an embodiment.
6 is a diagram showing a structure of resonators of a wireless power transmission apparatus according to an embodiment.
7 is a diagram illustrating resonators and targets of a wireless power transmission apparatus according to an exemplary embodiment.
8 and 9 are graphs showing wireless power transmission efficiency according to a phase of a voltage supplied to a resonator in a wireless power transmission apparatus according to an embodiment.
10 is a diagram illustrating an arrangement of resonators of a wireless power transmission apparatus according to an exemplary embodiment.
11 shows a structure of a resonator of a wireless power transmission device according to another embodiment.
12 is a flowchart of a wireless power transmission method according to an embodiment.
13 shows a distribution of a magnetic field in a resonator and a feeder according to an embodiment.
14 is a diagram showing the configuration of a resonator and a feeder according to an embodiment.
15 is a diagram illustrating a distribution of a magnetic field inside a resonator according to feeding of a feeder according to an exemplary embodiment.
16 shows an electric vehicle charging system according to an embodiment.

Hereinafter, embodiments according to one side will be described in detail with reference to the accompanying drawings.

Methods of performing communication between a source and a target include an in-band communication method and an out-band communication method. The in-band communication method means that the source and the target communicate at the same frequency as the frequency used for power transmission, and the out-band communication method means that the source and the target communicate using a separate frequency from the frequency used for power transmission. do.

1 shows a wireless power transmission system according to an embodiment.

Referring to FIG. 1, a wireless power transmission system according to an embodiment includes a source 110 and a target 120. The source 110 refers to a device that supplies wireless power, and the device may include all electronic devices capable of supplying power, such as pads, terminals, TVs, medical devices, and electric vehicles. The target 120 refers to a device receiving wireless power, and all electronic devices that require power may be included. In this case, the electronic device may include a pad, a terminal, a tablet, a medical device, an electric vehicle, and the like.

The source 110 may include a variable SMPS 111, a power amplifier 112, a matching network 113, a transmission control unit 114, and a communication unit 115.

Variable SMPS (Variable Switching Mode Power Supply) 111 generates a DC voltage by switching an AC voltage of several tens of Hz band output from a power supply. The variable SMPS (Variable SMPS) 111 may output a DC voltage of a constant level or may adjust the output level of the DC voltage under the control of the Tx Control Logic 114.

The variable SMPS 111 is a supply voltage according to the output power level of the power amplifier 112 so that the Class-E type power amplifier 112 can always operate in a highly efficient saturation region. Can be controlled to maintain maximum efficiency at all output levels.

In the case of using a commercial SMPS that is generally used instead of the variable SMPS 111, a variable DC/DC (Variable DC/DC) converter must be additionally used. Commercial SMPS and variable DC/DC (Variable DC/DC) converters have a power amplifier 112 so that the Class-E type power amplifier 112 can always operate in a highly efficient saturation region. By controlling the supply voltage according to the output power level of ), the maximum efficiency can be maintained at all output levels.

The power detector 116 may detect the output current and voltage of the variable SMPS 111 and transmit information on the detected current and voltage to the transmission control unit 114. In addition, the power detector 116 may detect the input current and voltage of the power amplifier 112.

The power amplifier 112 may generate power by converting a DC voltage of a certain level into an AC voltage by a switching pulse signal of several MHz to several tens of MHz. That is, the power amplifier 112 converts the DC voltage supplied to the power amplifier 112 into an AC voltage using the _{reference resonance frequency F Ref.} It can generate electric power or electric power for charging.

Here, the communication power means a small power of 0.1 to 1 mWatt, and the charging power means a large power of several milli (m) Watts to several kilo (K) Watts consumed in the device load of the target device. In the present specification, the term "charging" may be used to mean supplying power to a unit or element that charges power. In addition, the term "charging" may also be used in the sense of supplying power to a unit or element that consumes power. Here, the unit or element may include, for example, a battery, a display, an audio output circuit, a main processor, and various sensors.

Meanwhile, in the present specification, the "reference resonance frequency" is used as the meaning of the resonance frequency basically used by the source 110. In addition, "tracking frequency" is used as the meaning of the resonant frequency adjusted according to a preset method.

The transmission control unit 114 detects a reflected wave for "communication power" or "charge power", and between the target resonator 133 and the source resonator 131 based on the detected reflected wave. Detect mismatching. The transmission control unit 114 may detect a mismatch by detecting an envelope of the reflected wave or detect a mismatch by detecting the amount of power of the reflected wave.

The matching network 113 may compensate for an impedance mismatch between the source resonator 131 and the target resonator 133 with optimal matching under the control of the transmission control unit 114. The matching network 113 is a combination of a capacitor or an inductor and may be connected through a switch under the control of the transmission control unit 114.

The transmission control unit 114 calculates a voltage standing wave ratio (VSWR) based on the level of the output voltage of the source resonator 131 or the power amplifier 112 and the voltage level of the reflected wave, When the voltage standing wave ratio is greater than a preset value, it may be determined that the mismatch is detected.

In addition, when the voltage standing wave ratio (VSWR) is greater than a preset value, the transmission control unit 114 calculates the power transmission efficiency for each of the preset N tracking frequencies, and the power transmission efficiency is the best among the N tracking frequencies. The frequency F _Best can be determined, and the reference resonance frequency F _Ref can be adjusted to the F _Best.

In addition, the transmission control unit 114 may adjust the frequency of the switching pulse signal. The frequency of the switching pulse signal may be determined by the control of the transmission control unit 114. The transmission control unit 114 may generate a modulated signal for transmission to the target 120 by controlling the power amplifier 112. That is, the communication unit 115 may transmit the target 120 and various data 140 through in-band communication. In addition, the transmission control unit 114 may detect the reflected wave and demodulate a signal received from the target 120 through an envelope of the reflected wave.

The transmission control unit 114 may generate a modulated signal for performing in-band communication through various methods. The transmission control unit 114 may generate a modulated signal by turning on/off the switching pulse signal. In addition, the transmission control unit 114 may generate a modulated signal by performing delta-sigma modulation. The transmission control unit 114 may generate a pulse width modulated signal having a constant envelope.

The transmission control unit 114 may determine the initial wireless power to be transmitted to the target 120 in consideration of a temperature change of the source 110, a battery state of the target 120, a change in the amount of received power, or a temperature change of the target 120. have.

The source 110 may further include a temperature measurement sensor (not shown) for detecting a temperature change. Information on a battery state of the target 120, a change in the amount of received power, or a temperature change of the target 120 may be received from the target 120 through communication.

That is, the temperature change of the target 120 may be detected based on data received from the target 120.

At this time, the transmission control unit 114 uses a look-up-table in which an adjustment amount of the voltage supplied to the power amplifier 112 is stored according to a change in the temperature of the source 110 to the power amplifier 112 You can adjust the voltage supplied to it. For example, when the temperature of the source 110 increases, the transmission control unit 114 may lower the voltage supplied to the power amplifier 112.

Meanwhile, the communication unit 115 may perform out-band communication using a communication channel. The communication unit 115 may include a communication module such as Zigbee and Bluetooth. The communication unit 115 may transmit the target 120 and the data 140 through out-band communication.

The source resonator 131 transfers electromagnetic energy 130 to the target resonator 133. The source resonator 131 transfers “communication power” or “charge power” to the target 120 through magnetic coupling with the target resonator 133.

The target 120 may include a matching network 121, a rectifier 122, a DC/DC converter 123, a communication unit 124, and a reception control unit (Rx Control Logic) 125.

The target resonator 133 receives electromagnetic energy from the source resonator 131. That is, the target resonator 133 may receive “communication power” or “charge power” from the source 110 through magnetic coupling with the source resonator 131. Also, the target resonator 133 may receive various data 140 from the source 110 through in-band communication.

The target resonator 133 receives the initial wireless power determined in consideration of a temperature change of the source 110, a battery state of the target 120, a change in the amount of received power, or a temperature change of the target 120.

The matching network 121 may match the input impedance viewed from the source 110 side and the output impedance viewed from the load side. The matching network 121 may be formed of a combination of a capacitor and an inductor.

The rectifier 122 rectifies the AC voltage to generate a DC voltage. That is, the rectifier 122 may rectify the AC voltage received by the target resonator 133.

The DC/DC converter 123 adjusts the level of the DC voltage output from the rectifier 122 according to the capacity required by the load. For example, the DC/DC converter 123 may adjust the level of the DC voltage output from the rectifier 122 to 3 to 10 Volt.

The power detector 127 may detect the voltage of the input terminal 126 of the DC/DC converter 123 and the current and voltage of the output terminal. The detected voltage of the input terminal 126 may be used to calculate the transmission efficiency of power delivered from the source. The detected current and voltage of the output terminal may be used by the Rx Control Logic 125 to calculate the power delivered to the load. The transmission control unit 114 of the source 110 may determine the power to be transmitted from the source 110 in consideration of the required power of the load and the power transmitted to the load.

When the power of the output terminal calculated through the communication unit 124 is transmitted to the source 110, the source 110 may calculate the power to be transmitted.

The communication unit 124 may perform in-band communication for transmitting and receiving data using a resonant frequency. In this case, the reception control unit 125 may detect a signal between the target resonator 133 and the rectifier 122 to demodulate the received signal or detect an output signal of the rectifier 122 to demodulate the received signal. That is, the reception control unit 125 may demodulate a message received through in-band communication. In addition, the reception control unit 125 may modulate a signal transmitted to the source 110 by adjusting the impedance of the target resonator 133 through the matching network 121. As a simple example, the reception control unit 125 may increase the impedance of the target resonator 133 so that the reflected wave is detected by the transmission control unit 114 of the source 110. Depending on whether a reflected wave is generated, the transmission control unit 114 of the source 110 may detect a first value (eg, binary "0") or a second value (eg, binary "1"). .

The communication unit 124 includes "the type of the product of the target", "the manufacturer information of the target", "the model name of the target", "the battery type of the target", "the charging method of the target", " The impedance value of the load of the target", "Information on the characteristics of the target resonator", "Information on the frequency band used by the target", "The amount of power required by the target", "The target A response message including "unique identifier" and "version or standard information of the target product" may be transmitted to the communication unit 115 of the source 110.

Meanwhile, the communication unit 124 may perform out-band communication using a separate communication channel. The communication unit 124 may include a communication module such as Zigbee and Bluetooth. The communication unit 124 may transmit and receive the source 110 and the data 140 through out-band communication.

The communication unit 124 receives a wake-up request message from the source 110, the power detector 127 detects the amount of power received by the target resonator 133, and the communication unit 124 is a target Information on the amount of power received by the resonator 133 may be transmitted to the source 110. At this time, the information on the amount of power received by the target resonator 133 is "the input voltage value and current value of the rectifier 122", "the output voltage value and current value of the rectifier 122", or "DC/DC The output voltage value and current value of the converter 123".

2 shows a wireless charging environment in which a wireless power transmission device according to an embodiment can be used.

Referring to FIG. 2, a 3D (Dimension) wireless charging environment that requires power transmission from one source to targets located in various positions and directions will come in the future.

In the 3D wireless charging environment as shown in FIG. 2, even when the target is not located at a specific distance and direction from the source, but at an arbitrary distance and direction, power needs to be charged at a predetermined efficiency or higher.

3 is a block diagram of an apparatus for transmitting power wirelessly according to an exemplary embodiment.

Referring to FIG. 3, a wireless power transmission apparatus according to an embodiment may include a power transmission unit 310, a feeding unit 320, and a control unit 330. The wireless power transmission device may further include a communication unit 340.

The power transmission unit 310 may include a plurality of source resonators 311, 313, and 315 that wirelessly transmit power through magnetic coupling with a target resonator. Here, three source resonators are displayed, but are not limited to three, and two or more source resonators may be included in the power transmission unit 310.

The feeding unit 320 may supply power to the plurality of source resonators 311, 313, and 315. The feeding unit 320 may transfer power supplied from a power supply to a plurality of source resonators 311, 313, and 315.

The controller 330 may control at least one of a voltage intensity and a current intensity of power supplied from the feeding unit 320. The controller 330 may control the voltage intensity or the current intensity of the power source. Power in a controlled state is supplied from a power source to the feeding unit 320, and the feeding unit 320 may transfer the supplied power to the plurality of source resonators 311, 313, and 315.

For example, the control unit 330 includes a plurality of source resonators 311, 313, 315 connected to an input terminal of an N port network (not shown) and an output terminal of an N port network (not shown). The impedance parameter of the N-port network (not shown) can be calculated in the relationship of the connected target resonator (not shown). Examples of the impedance parameter may include parameters representing a relationship between inputs and outputs of various N-port networks, such as a Z parameter, an h parameter, a a parameter, and a b parameter. The N-port network will be described in more detail with reference to FIG. 5.

The controller 330 may control at least one of a voltage intensity and a current intensity of power supplied to each of the plurality of source resonators 311, 313, and 315 based on the calculated impedance parameter.

The plurality of source resonators 311, 313, and 315 are each of a source resonator 311, a source resonator 313, and a source resonator 315 coupled to each other, and each source resonator 311 and source resonator 313 ) And the source resonator 315 may be at least one of a form separated from each other. An example of a form combined with each other may be a form shown in FIGS. 6 and 7, and an example of a form separated from each other may be a form illustrated in FIG. 10.

When the test voltage and the test current are applied to the plurality of source resonators 311, 313, and 315, the communication unit 340 receives information on the current and voltage applied to the load of the wireless power receiving device (not shown). You can receive it. When test power is applied to the plurality of source resonators 311, 313, and 315, the communication unit 340 may receive information on power received from the wireless power receiving device. In this case, the information on the received power may include information on the reception current and information on the reception voltage. The communication unit 340 may communicate with the wireless power receiver in an in-band communication method or an out-band communication method.

The controller 330 may control at least one of a voltage intensity and a current intensity of power supplied to each of the source resonators 311, 313, and 315 based on the power transmission efficiency to the target resonator (not shown). have. The control unit 330 may calculate the power transmission efficiency based on information on the received power of the wireless power receiving device received through the communication unit 340.

The controller 330 may control at least one of a voltage intensity and a current intensity of power supplied to each of the source resonators 311, 313, and 315 so as to satisfy a preset power transmission efficiency. For example, if 80% is previously set as the power transmission efficiency, the controller 330 may control at least one of the voltage intensity and the current intensity to be 80%. At this time, the control unit 330 may supply power to each of the source resonators 311, 313, and 315 at different voltage strengths or current strengths, or the same voltage strength or current strength to each of the source resonators 311, 313, and 315. Power can also be supplied with current strength.

The controller 330 may adjust at least one of a voltage phase and a current phase of power supplied from the feeding unit 320. The controller 330 may control at least one of a voltage phase and a current phase based on power transmission efficiency to the target resonator (not shown). For example, the controller 330 may control at least one of a voltage phase and a current phase to satisfy a target value of a preset power transmission efficiency.

The controller 330 calculates an impedance parameter of an N port network (not shown), and based on the impedance parameter, at least one of a voltage phase and a current phase of power supplied to each of the plurality of source resonators 311, 313, and 315 You can control one.

The controller 330 may receive information on the received power of the wireless power receiver from the communication unit 340 whenever controlling the voltage intensity or the current intensity, calculate power transmission efficiency, and compare it with a preset target value. . The controller 330 calculates the power transmission efficiency by adjusting the voltage intensity or the current intensity, and supplies the voltage intensity or current intensity to the source resonators 311, 313, 315 when a preset target value is satisfied. Alternatively, it can be determined by the current intensity. Even when controlling at least one of the voltage phase and the current phase, the controller 330 may compare the power transmission efficiency to determine at least one of an optimal voltage phase and a current phase that satisfy a preset target value.

The control unit 330 may estimate an optimal voltage intensity or current intensity by performing a simulation in a range of a voltage intensity or a range of a current intensity that can be adjusted for each of the source resonators 311, 313, and 315. In this case, the simulation may be performed using an optimization tool or an optimization algorithm as a measurement on software. The controller 330 may determine the estimated voltage intensity or current intensity as an optimal voltage intensity or current intensity as a result of the simulation. Even when controlling at least one of the voltage phase and the current phase, the controller 330 may determine at least one of the voltage phase and the current phase calculated as an optimum value as at least one of the optimum voltage phase and the current phase using simulation. have.

Each of the plurality of source resonators 311, 313, and 315 may include a first transmission line, a first conductor, a second conductor, and a first capacitor.

The first transmission line may include a first signal conductor portion and a second signal conductor portion, and a first signal conductor portion and a first ground conductor portion corresponding to the second signal conductor portion.

The first conductor may electrically connect the first signal conductor portion and the first ground conductor portion, and the second conductor may be separated from the first ground conductor portion to be electrically connected to the second signal conductor portion.

The first capacitor may be inserted between the first signal conductor portion and the second signal conductor portion in series with respect to a current flowing through the first signal conductor portion and the second signal conductor portion. More specifically, each of the plurality of source resonators 311, 313, and 315 may have the structure shown in FIG. 14.

4 is a block diagram of an apparatus for transmitting power wirelessly according to another exemplary embodiment.

Referring to FIG. 4, a wireless power transmission apparatus according to an embodiment may include a power transmission unit 410, a feeding unit 420, and a control unit 430. The wireless power transmission device may further include a communication unit 440.

The power transmission unit 410 may include a plurality of source resonators 411 and 413 that wirelessly transmit power through magnetic coupling with a target resonator. Although two source resonators are shown here, the present invention is not limited to two, and two or more source resonators may be included in the power transmission unit 410.

The feeding unit 420 may supply power to the plurality of source resonators 411 and 413. The feeding unit 420 may transmit power supplied from a power supply to the plurality of source resonators 411 and 413.

The controller 430 may control at least one of a voltage intensity and a current intensity of power supplied from the feeding unit 420. The controller 430 may control the voltage intensity or the current intensity of the power source. Power in a controlled state is supplied from the power source to the feeding unit 420, and the feeding unit 420 may transfer the supplied power to the plurality of source resonators 411 and 413.

For example, the control unit 430 may include a plurality of source resonators 411 and 413 connected to an input terminal of an N port network (not shown) and a target connected to an output terminal of an N port network (not shown). The impedance parameter of the N-port network (not shown) can be calculated in relation to the resonator (not shown). Examples of the impedance parameter may include parameters representing a relationship between inputs and outputs of various N-port networks, such as a Z parameter, an h parameter, a a parameter, and a b parameter. The N-port network will be described in more detail with reference to FIG. 5.

The controller 430 may control at least one of a voltage intensity and a current intensity of power supplied to each of the plurality of source resonators 411 and 413 based on the calculated impedance parameter.

The plurality of source resonators 411 and 413 are at least one of a form in which each source resonator 411 and source resonator 413 are coupled to each other, and a form in which each source resonator 411 and source resonator 413 are separated from each other. It can be in one form. An example of a form combined with each other may be a form shown in FIGS. 6 and 7, and an example of a form separated from each other may be a form illustrated in FIG. 10.

When the test voltage and the test current are applied to the plurality of source resonators 411 and 413, the communication unit 440 may receive information on the current and voltage applied to the load of the wireless power receiving device (not shown). I can. When the test power is applied to the plurality of source resonators 411 and 413, the communication unit 440 may receive information on power received from the wireless power receiving device. In this case, the information on the received power may include information on the reception current and information on the reception voltage. The communication unit 440 may communicate with the wireless power receiving device in an in-band communication method or an out-band communication method.

The control unit 430 may include a calculation unit 431, an optimization unit 433, and a determination unit 435.

The calculation unit 431 may calculate power transmission efficiency and impedance parameters of the N-port network based on information on current and voltage received from the communication unit 440. The power transmission efficiency may be calculated by comparing the received power of the wireless power receiving device (not shown) calculated by the current and voltage received by the communication unit 440 compared to the power transmitted by the power transmission unit 410. The impedance parameter can be calculated by applying conditions necessary for calculation for each impedance parameter at the input and output terminals of the N-port network.

The optimizer 433 may perform optimization based on the impedance parameter calculated by the calculation unit 431 with a target value of power transmission efficiency as a condition. When the impedance parameter value is calculated, the optimizer 433 may estimate at least one of a voltage intensity, a current intensity, a voltage phase, and a current phase satisfying the power transmission efficiency set as the target value. Alternatively, the optimizer 433 may estimate a combination of at least two or more of voltage intensity, current intensity, voltage phase, and current phase satisfying the power transmission efficiency set as the target value.

The determiner 435 may determine at least one of a voltage intensity and a current intensity supplied to each of the plurality of source resonators 411 and 413 based on the optimization result.

The optimization unit 433 sequentially changes at least one of the voltage intensity and the current intensity to each of the plurality of source resonators 411 and 413 within the voltage intensity range and the current intensity range that can be applied by the feeding unit 420. Optimization can be performed.

The optimizer 433 may perform optimization by executing an optimization algorithm under the condition of the impedance parameter and the power transmission efficiency set to the target value. In this case, as a variable, at least one of the sequentially changed voltage intensity and current intensity within the range of the voltage intensity and the current intensity that can be applied may be used.

The optimization unit 433 randomly changes at least one of the voltage intensity and the current intensity to each of the plurality of source resonators 411 and 413 within the voltage intensity range and the current intensity range that can be applied by the feeding unit 420. Optimization can be performed. In this case, as a variable, the optimizer 433 may use at least one of a randomly changed voltage intensity and a current intensity within a voltage intensity range and a current intensity range that can be applied.

The optimizer 433 may provide at least one of a voltage intensity and a current intensity to each of the plurality of source resonators 411 and 413 based on the lookup table within the voltage intensity range and the current intensity range that can be applied by the feeding unit 420. You can perform the optimization by changing. In this case, the optimizer 433 may use at least one of the changed voltage intensity and current intensity based on the lookup table within the range of the voltage intensity and the current intensity that can be applied as a variable. The lookup table may mean a table in which voltage intensity, current intensity, voltage phase, and current phase are statistically matched according to power transmission efficiency. Alternatively, it may mean a table in which statistical data is reflected when the condition of power distribution is satisfied.

The optimizer 433 may estimate at least one of a voltage intensity and a current intensity satisfying a target value of power transmission efficiency based on an N-port matrix relational expression and an impedance parameter derived from an N-port network (not shown). That is, as a condition of the optimization algorithm, an N-port matrix relational expression, an impedance parameter, and a target value of power transmission efficiency may be reflected.

The determiner 435 may determine at least one of a voltage phase and a current phase supplied to each of the plurality of source resonators 411 and 413 based on the result of the optimization of the optimizer 433.

The controller 430 may control at least one of a voltage intensity and a current intensity of power supplied to each of the source resonators 411 and 413 based on power transmission efficiency to the target resonator (not shown). The control unit 430 may calculate the power transmission efficiency based on information on the received power of the wireless power receiving device received through the communication unit 440.

The controller 430 may control at least one of a voltage intensity and a current intensity of power supplied to each of the source resonators 411 and 413 so as to satisfy a preset power transmission efficiency. For example, if 80% is previously set as the power transmission efficiency, the controller 430 may control at least one of the voltage intensity and the current intensity to be 80%. At this time, the control unit 430 may supply power to each of the source resonators 411 and 413 at different voltage strengths or current strengths, and power at the same voltage or current strength to each of the source resonators 411 and 413 You can also supply.

The control unit 430 may adjust at least one of a voltage phase and a current phase of power supplied from the feeding unit 420. The controller 430 may control at least one of a voltage phase and a current phase based on power transmission efficiency to the target resonator (not shown). For example, the controller 430 may control at least one of a voltage phase and a current phase to satisfy a target value of a preset power transmission efficiency.

5 shows an N port network of a wireless power transmission device according to an embodiment.

5 shows an N-port network when there are three source resonators and one target resonator. The N value of the N port is determined according to the number of input terminals and the number of output terminals.Three source resonators are connected to the input terminal of the N port network, and one target resonator is connected to the output terminal to form a 4-port network 550. I can.

Referring to FIG. 5, the apparatus for transmitting power wirelessly may include a power source 510 and three source resonators. The power source 510 may supply power to each source resonator. Each source resonator may be located at the first port 520, the second port 530, and the third port 540. For example, the power supply 510 may be located for each port such as _{V s1} , V _s2 , and V _s3. Z _s1 is the impedance of V _{s1 , Z s2} is the impedance of V _s2 , and Z _s3 is the impedance of V _s3.

The apparatus for receiving wireless power may include a target resonator and a load. The target resonator may be located in the fourth port 560. The load can be expressed as _{Z load.} The voltage applied to the target resonator and the load may be represented by _{V 4} , and the current output from the target resonator _{may be represented by I 4.}

The voltage applied to the first port 520 is V ₁ , the output current is I ₁ , and the input impedance of the first port 520 is Z _in1 .

The voltage applied to the second port 530 is V ₂ , the output current is I ₂ , and the input impedance of the second port 530 is Z _in 2.

The voltage applied to the third port 540 is V ₃ , the output current is I ₃ , and the input impedance of the third port 540 is Z _in3 .

In the 4-port network 550, an input terminal and an output terminal may be expressed in a 4-port matrix relational expression using an impedance parameter. For example, if the impedance parameter is the Z parameter, it may be summarized as [Equation 1].

[Equation 1]

Using [Equation 1], the power transmission efficiency can be calculated as in [Equation 2].

[Equation 2]

P _avs is the power supplied to each source resonator, and P _L is the power delivered to the load.

Looking at [Equation 2], it can be seen that the power transmission efficiency is affected by the absolute value of the voltage supplied from the power source 510 to each source resonator and the absolute value of the current flowing through the load.

When test power is supplied from the power source 510, the Z parameter value may be calculated. Using the Z parameter value, I ₄ can be expressed as a relational expression of V _s1 , V _s2 , and V _s3. As a result, the power transmission efficiency may be affected by the absolute value of the voltage supplied to the source resonator. The absolute value of the voltage may be determined according to the strength of the voltage and the phase of the voltage.

Accordingly, the wireless power transmission apparatus may adjust the power transmission efficiency by adjusting the strength of the voltage supplied to the source resonator and the phase of the voltage. The power supplied to the source resonator may be influenced by the current strength and the current phase. The wireless power transmission apparatus may control power transmission efficiency by adjusting the intensity of the current flowing through the source resonator and the phase of the current.

In addition, the wireless power transmission apparatus can maintain power transmission efficiency even in a complex environment such as a 3D wireless charging environment by adjusting the intensity or phase of a voltage or current applied to a plurality of source resonators.

6 is a diagram showing a structure of resonators of a wireless power transmission apparatus according to an embodiment.

Referring to FIG. 6, the power transmitter of the wireless power transmitter may include a plurality of source resonators 610, 620, and 630. The source resonator 610 may include a plane parallel to the xy plane, the source resonator 620 may include a plane parallel to the yz plane, and the source resonator 630 may include a plane parallel to the zx plane. . The source resonator 610, the source resonator 620, and the source resonator 630 have a combined structure.

The target 640 may wirelessly receive power through magnetic coupling with the plurality of source resonators 610, 620, and 630. In this case, it is assumed that the angle formed by the target 640 and the plurality of source resonators 610, 620, and 630 at the location where the target 640 is located is 0 degrees.

The target 640 is positioned facing the source resonator 630.

By adjusting the intensity or phase of the voltage supplied to each of the source resonators 610, 620, and 630, the intensity or phase of the current, the transmission efficiency of the power delivered to the target 640 is changed. Even in the case, it can be maintained above a certain efficiency.

In FIG. 6, three source resonators 610, 620, and 630 are used, but if the number of resonators is two or more, all of them can be applied. In addition, even when there are multiple targets 640, power distribution for each target may be adjusted by adjusting the intensity or phase of the voltage supplied to the plurality of source resonators, and the intensity or phase of the current.

7 is a diagram illustrating resonators and targets of a wireless power transmission apparatus according to an exemplary embodiment.

Referring to FIG. 7, the target 740 is positioned at an angle of 30 degrees with the source resonators 710, 720, and 730. Compared with the case of FIG. 6, even in the case of FIG. 7, the intensity or phase of the voltage supplied to the source resonators 710, 720, and 730, and the intensity or phase of the current are adjusted, thereby transmitting power to the target 740 Efficiency can be maintained.

8 and 9 are graphs showing wireless power transmission efficiency according to a phase of a voltage supplied to a resonator in a wireless power transmission apparatus according to an embodiment.

FIG. 8 is a graph showing power transmission efficiency from the source resonators 610, 620, and 630 to the target 640 in the case of FIG. 6. In this case, the magnitude of the voltage supplied to the source resonators 610, 620, and 630 is the same, and the phase of the voltage supplied to the source resonator 620 and the source resonator 630 is changed. The graph of FIG. 8 may be generated through a simulation of changing the phase of the voltage supplied to the source resonator 620 and the source resonator 630 as above.

As the phases of the voltages supplied to the source resonator 620 and the source resonator 630 change, the power transmission efficiency also changes. In the graph, the darker the contrast, the higher the power transmission efficiency. Approximately, when the phase of the voltage supplied to the source resonator 620 is 70 degrees 810 and the phase of the voltage supplied to the source resonator 630 is 100 degrees 820, it can be estimated that the power transmission efficiency is the highest. have.

In FIG. 8, only a graph for changing the phases of the voltages supplied to the two source resonators is shown, but when the phases of the voltages supplied to the three source resonators are all changed, the intensity of the voltages supplied to the three source resonators A graph may be generated through simulation when all of the values are changed and the phase of the voltage and the intensity of the voltage are both changed.

9 is a graph showing power transmission efficiency from the source resonators 710, 720, and 730 to the target 740 in the case of FIG. 7. That is, FIG. 9 is a graph showing power transmission efficiency when the target 740 is positioned at an angle of 30 degrees to the source resonators 710, 720, and 730. In this case, the magnitude of the voltage supplied to the source resonators 710, 720, and 730 is the same, and the phase of the voltage supplied to the source resonator 720 and the source resonator 730 is changed.

Roughly, when the phase of the voltage supplied to the source resonator 720 is 170 degrees (910) and the phase of the voltage supplied to the source resonator 730 is 100 degrees (920), it can be estimated that the power transmission efficiency is the highest. have.

10 is a diagram illustrating an arrangement of resonators of a wireless power transmission apparatus according to an exemplary embodiment.

Referring to FIG. 10, source resonators of the wireless power transmission apparatus may have a separate form. The source resonator 1010 and the source resonator 1020 receive power from the feeding unit, but may be separated from each other rather than coupled to each other.

The source resonator 1010 and the target 1030 from the source resonator 1020 may receive power wirelessly through magnetic coupling. By adjusting at least one of the voltage intensity and the current intensity of the power supplied from the feeding unit to the source resonator 1010 and the source resonator 1020, the transmission efficiency of the power delivered to the target 1030 is reduced to the charging of the target 1030. It can be maintained beyond what is necessary.

Alternatively, by adjusting at least one of a voltage phase and a current phase of the power supplied from the feeding unit to the source resonator 1010 and the source resonator 1020, the transmission efficiency of the power delivered to the target 1030 is higher than the preset target efficiency. Can be maintained.

11 shows a structure of a resonator of a wireless power transmission device according to another embodiment.

Referring to FIG. 11, the source resonator of the wireless power transmission apparatus may be in the form of a hexahedron. At this time, the source resonator may be composed of a plurality of resonators, the resonator 1110 and the resonator 1140 are parallel to each other, the resonator 1120 and the resonator 1150 are parallel to each other, the resonator 1130 and the resonator 1160 ) Can have planes parallel to each other.

12 is a flowchart of a wireless power transmission method according to an embodiment.

In step 1210, the wireless power transmission apparatus may control at least one of a voltage intensity and a current intensity of power supplied to the plurality of source resonators.

The wireless power transmission apparatus according to an embodiment may control at least one of a voltage intensity and a current intensity of power supplied to each of the plurality of source resonators based on power transmission efficiency.

The apparatus for transmitting power wirelessly according to an embodiment may calculate an impedance parameter of an N port network in a relationship between a plurality of source resonators connected to an input terminal of an N-port network and the target resonator connected to an output terminal of an N-port network.

The wireless power transmission apparatus according to an embodiment may control at least one of a voltage intensity and a current intensity of power supplied to each of the plurality of source resonators based on an impedance parameter.

When a test voltage and a test current are applied to a plurality of source resonators, the apparatus for transmitting power wirelessly according to an embodiment may receive information on a current and a voltage applied to a load of the apparatus for receiving power wirelessly.

The wireless power transmission apparatus according to an embodiment may calculate power transmission efficiency and impedance parameters of the N-port network based on information on received current and voltage.

The wireless power transmission apparatus according to an embodiment may perform optimization based on the target value of the power transmission efficiency in the impedance parameter.

The wireless power transmission apparatus according to an embodiment may determine at least one of a voltage strength and a current strength supplied to each of the plurality of source resonators based on the result of the optimization.

The wireless power transmission apparatus according to an embodiment may control at least one of a voltage phase and a current phase of power supplied to each of the plurality of source resonators based on power transmission efficiency.

In step 1220, the apparatus for transmitting power wirelessly may supply power to a plurality of source resonators. The wireless power transmission apparatus may supply power to a plurality of source resonators through a feeder.

In step 1230, the wireless power transmission apparatus may wirelessly transmit power through magnetic coupling with a target resonator through a plurality of source resonators. The wireless power transmission apparatus may adjust the power transmission efficiency to the target resonator by adjusting the strength of the voltage applied to each of the plurality of source resonators and the phase of the voltage. The wireless power transmission apparatus may adjust the power transmission efficiency to the target resonator by adjusting the intensity of the current flowing through each of the plurality of source resonators and the phase of the current.

In FIGS. 13 to 16, "resonator" includes a source resonator and a target resonator.

The resonators of FIGS. 13 to 16 can be applied to the resonators described in FIGS. 1 to 12.

13 shows a distribution of a magnetic field in a resonator and a feeder according to an embodiment.

When the resonator is supplied with power through a separate feeder, a magnetic field is generated in the feeder, and a magnetic field is generated in the resonator.

Referring to FIG. 13A, a magnetic field 1330 is generated as an input current flows from the feeder 1310. The direction 1331 of the magnetic field inside the feeder 1310 and the direction 1333 of the magnetic field outside have opposite phases. An induced current is generated in the resonator 1320 by the magnetic field 1330 generated in the feeder 1310. At this time, the direction of the induced current is opposite to the direction of the input current.

A magnetic field 1340 is generated in the resonator 1320 by the induced current. The direction of the magnetic field has the same direction inside the resonator 1320. Accordingly, the direction 1341 of the magnetic field generated inside the feeder 1310 by the resonator 1320 and the direction 1343 of the magnetic field generated outside the feeder 1310 have the same phase.

As a result, when the magnetic field generated by the feeder 1310 and the magnetic field generated by the resonator 1320 are synthesized, the strength of the magnetic field is weakened inside the feeder 1310, and the strength of the magnetic field is strengthened outside the feeder 1310. do. Accordingly, when power is supplied to the resonator 1320 through the feeder 1310 having the structure as shown in FIG. 13, the strength of the magnetic field is weak at the center of the resonator 1320 and the strength of the magnetic field is strong at the outer side. When the distribution of the magnetic field on the resonator 1320 is not uniform, it is difficult to perform impedance matching because the input impedance changes from time to time. In addition, since wireless power transmission is well performed in areas with strong magnetic field strength, and wireless power transmission is not performed well in areas with weak magnetic field strength, power transmission efficiency decreases on average.

13B shows the structure of a wireless power transmission apparatus in which the resonator 1350 and the feeder 1360 have a common ground. The resonator 1350 may include a capacitor 1351. The feeder 1360 may receive an RF signal through the port 1361. An RF signal is input to the feeder 1360 to generate an input current. The input current flowing through the feeder 1360 generates a magnetic field, and an induced current is induced in the resonator 1350 from the magnetic field. In addition, a magnetic field is generated from the induced current flowing through the resonator 1350. In this case, the direction of the input current flowing through the feeder 1360 and the direction of the induced current flowing through the resonator 1350 have opposite phases. Therefore, in the region between the resonator 1350 and the feeder 1360, the direction 1371 of the magnetic field generated by the input current and the direction 1373 of the magnetic field generated by the induced current have the same phase. The strength is strengthened. On the other hand, inside the feeder 1360, since the direction 1381 of the magnetic field generated by the input current and the direction 1383 of the magnetic field generated by the induced current have opposite phases, the strength of the magnetic field is weakened. As a result, the strength of the magnetic field may be weakened at the center of the resonator 1350, and the strength of the magnetic field may be enhanced at the outer side of the resonator 1350.

The feeder 1360 may determine an input impedance by adjusting an area inside the feeder 1360. Here, the input impedance refers to the impedance seen when looking at the resonator 1350 from the feeder 1360. When the area inside the feeder 1360 increases, the input impedance increases, and when the inside area decreases, the input impedance decreases. However, even when the input impedance decreases, since the distribution of the magnetic field inside the resonator 1350 is not constant, the input impedance value is not constant according to the position of the target device. Therefore, a separate matching network is required for matching the output impedance of the power amplifier and the input impedance. When the input impedance increases, a separate matching network may be required to match a large input impedance to a small output impedance.

14 is a diagram showing the configuration of a resonator and a feeder according to an embodiment.

Referring to FIG. 14A, the resonator 1410 may include a capacitor 1411. The feeding part 1420 may be electrically connected to both ends of the capacitor 1411.

14B is a diagram showing the structure of (a) in more detail. In this case, the resonator 1410 may include a first transmission line, a first conductor 1441, a second conductor 1442, and at least one first capacitor 1450.

The first capacitor 1450 is inserted in series at a position between the first signal conductor portion 1431 and the second signal conductor portion 1432 in the first transmission line, and accordingly, an electric field is applied to the first capacitor ( 1450). In general, a transmission line includes at least one conductor at the top and at least one conductor at the bottom, current flows through the conductor at the top, and the conductor at the bottom is electrically grounded. In this specification, the conductor above the first transmission line is divided into a first signal conductor portion 1431 and a second signal conductor portion 1432, and the conductor below the first transmission line is referred to as a first ground conductor portion ( 1433).

As shown in (b) of FIG. 14, the resonator has a two-dimensional structure. The first transmission line includes a first signal conductor portion 1431 and a second signal conductor portion 1432 at an upper portion, and a first ground conductor portion 1433 at a lower portion. The first signal conductor portion 1431 and the second signal conductor portion 1432 and the first ground conductor portion 1433 are disposed to face each other. Current flows through the first signal conductor portion 1431 and the second signal conductor portion 1432.

In addition, as shown in (b) of FIG. 14, one end of the first signal conductor portion 1431 is shorted to the first conductor 1451 and the other end is connected to the first capacitor 1450. do. In addition, one end of the second signal conductor portion 1432 is grounded with the second conductor 1442, and the other end is connected to the first capacitor 1450. As a result, the first signal conductor portion 1431, the second signal conductor portion 1432 and the first ground conductor portion 1433, and the conductors 1441 and 1442 are connected to each other, so that the resonator has an electrically closed loop structure. Have. Here, the'loop structure' includes all of a circular structure, a polygonal structure such as a square, etc., and'having a loop structure' means that it is electrically closed.

The first capacitor 1450 is inserted in the middle of the transmission line. More specifically, the first capacitor 1450 is inserted between the first signal conductor portion 1431 and the second signal conductor portion 1432. In this case, the first capacitor 1450 may have a shape such as a lumped element and a distributed element. In particular, the dispersed capacitor having the form of a dispersion element may include zigzag-shaped conductor lines and a dielectric having a high dielectric constant between the conductor lines.

As the first capacitor 1450 is inserted into the transmission line, the source resonator may have a metamaterial characteristic. Here, the metamaterial is a material having special electrical properties that cannot be found in nature, and has an artificially designed structure. The electromagnetic properties of all materials in nature have inherent permittivity or permeability, and most materials have positive dielectric constant and positive permeability.

In most materials, the right hand rule is applied to electric fields, magnetic fields, and pointing vectors, so these materials are referred to as RHM (Right Handed Materials). However, a metamaterial is a material having a dielectric constant or permeability that does not exist in nature, and depending on the sign of the permittivity or permeability, an epsilon negative (ENG) material, a mu negative (MNG) material, a double negative (DNG) material, a negative refractive index (NRI) index) substances, LH (left-handed) substances, etc.

In this case, if the capacitance of the first capacitor 1450 inserted as the concentration element is properly determined, the source resonator may have metamaterial characteristics. In particular, by appropriately adjusting the capacitance of the first capacitor 1450, the source resonator can have a negative permeability, so the source resonator can be referred to as an MNG resonator. Criterions for determining the capacitance of the first capacitor 1450 may be various. A criterion that allows the source resonator to have metamaterial properties, a criterion that allows the source resonator to have a negative permeability at the target frequency, or the zeroth-order resonance characteristic of the source resonator at the target frequency There may be a premise to have a, and the capacitance of the first capacitor 1450 may be determined under at least one of the aforementioned premises.

The MNG resonator may have a zero-th resonance (Zeroth-Order Resonance) characteristic having a frequency when a propagation constant is 0 as a resonance frequency. Since the MNG resonator may have a zero-th resonance characteristic, the resonance frequency may be independent of the physical size of the MNG resonator. That is, as will be described again below, in order to change the resonant frequency in the MNG resonator, it is sufficient to properly design the first capacitor 1450, and thus the physical size of the MNG resonator may not be changed.

In addition, since the electric field is concentrated on the first capacitor 1450 inserted in the transmission line in the near field, the magnetic field becomes dominant in the near field due to the first capacitor 1450. In addition, since the MNG resonator may have a high Q-factor by using the first capacitor 1450 of the lumped element, the efficiency of power transmission may be improved. For reference, the Q-factor represents the degree of ohmic loss or the ratio of reactance to resistance in wireless power transmission.It can be understood that the greater the Q-factor, the greater the efficiency of wireless power transmission. .

Further, although not shown in FIG. 14B, a magnetic core penetrating the MNG resonator may be further included. Such a magnetic core may perform a function of increasing the power transmission distance.

Referring to FIG. 14B, the feeding part 1420 includes a second transmission line, a third conductor 1471, a fourth conductor 1472, a fifth conductor 1481, and a sixth conductor 1482. can do.

The second transmission line includes a third signal conductor portion 1461 and a fourth signal conductor portion 1462 at an upper portion, and a second ground conductor portion 1463 at a lower portion. The third signal conductor portion 1461 and the fourth signal conductor portion 1462 and the second ground conductor portion 1463 are disposed to face each other. Current flows through the third signal conductor portion 1461 and the fourth signal conductor portion 1462.

In addition, as shown in (b) of FIG. 14, one end of the third signal conductor portion 1461 is shorted to the third conductor 1471 and the other end is connected to the fifth conductor 1481. do. In addition, one end of the fourth signal conductor portion 1462 is grounded with the fourth conductor 1472, and the other end is connected with the sixth conductor 1482. The fifth conductor 1481 is connected to the first signal conductor portion 1431, and the sixth conductor 1482 is connected to the second signal conductor portion 1432. The fifth conductor 1481 and the sixth conductor 1482 are connected in parallel to both ends of the first capacitor 1450. At this time, the fifth conductor 1481 and the sixth conductor 1482 may be used as input ports for receiving an RF signal.

As a result, the third signal conductor portion 1461, the fourth signal conductor portion 1462 and the second ground conductor portion 1463, the third conductor 1471, the fourth conductor 1472, the fifth conductor 1481, The sixth conductor 1482 and the resonator 1410 are connected to each other, so that the resonator 1410 and the feeding part 1420 have a loop structure in which the resonator 1410 and the feeding part 1420 are electrically closed. Here, the'loop structure' includes both a circular structure and a polygonal structure such as a square. When an RF signal is input through the fifth conductor 1481 or the sixth conductor 1482, the input current flows through the feeding unit 1420 and the resonator 1410, and by the magnetic field generated by the input current, the resonator ( 1410) induced current is induced. Since the direction of the input current flowing from the feeding part 1420 and the direction of the induced current flowing from the resonator 1410 are formed in the same direction, the strength of the magnetic field is strengthened in the center of the resonator 1410, and the magnetic field is strengthened at the outside of the resonator 1410. The strength of the is weakened.

Since the input impedance may be determined by the area of the region between the resonator 1410 and the feeding unit 1420, a separate matching network is not required to perform matching between the output impedance of the power amplifier and the input impedance. Even when the matching network is used, since the input impedance can be determined by adjusting the size of the feeding unit 1420, the structure of the matching network can be simplified. The simple matching network structure minimizes the matching loss of the matching network.

The second transmission line, the third conductor 1471, the fourth conductor 1472, the fifth conductor 1481, and the sixth conductor 1482 may form the same structure as the resonator 1410. That is, when the resonator 1410 has a loop structure, the feeding unit 1420 may also have a loop structure. In addition, when the resonator 1410 has a circular structure, the feeding part 1420 may also have a circular structure.

15 is a diagram illustrating a distribution of a magnetic field inside a resonator according to feeding of a feeding unit according to an exemplary embodiment.

In wireless power transmission, feeding may mean supplying power to a source resonator. In addition, feeding in wireless power reception may mean supplying AC power to the rectifying unit. 15A shows the direction of the input current flowing from the feeding part and the direction of the induced current induced from the source resonator. Further, (a) of FIG. 15 shows the direction of the magnetic field generated by the input current of the feeding unit and the direction of the magnetic field generated by the induced current of the source resonator. FIG. 15A is a more simplified view of the resonator 1410 and the feeding unit 1420 of FIG. 14. FIG. 15B shows an equivalent circuit of the feeding unit 1420 and the resonator 1410 of FIG. 14.

Referring to FIG. 15A, the fifth conductor 1481 or the sixth conductor 1482 of the feeding part 1420 of FIG. 14 may be used as the input port 1510. The input port 1510 receives an RF signal. The RF signal can be output from a power amplifier. The power amplifier can increase or decrease the amplitude of the RF signal according to the needs of the target device. The RF signal input from the input port 1510 may be displayed in the form of an input current flowing through the feeding unit 1420. The input current flowing through the feeding unit 1420 flows in a clockwise direction along the transmission line of the feeding unit 1420. By the way, the fifth conductor 1481 of the feeding part 1420 is electrically connected to the resonator 1410. More specifically, the fifth conductor 1481 is connected to the first signal conductor portion 1431 of the resonator 1410. Accordingly, the input current flows not only to the feeding unit 1420 but also to the resonator 1410. In the resonator 1410, the input current flows in a counterclockwise direction. A magnetic field is generated by an input current flowing through the resonator 1410, and an induced current is generated in the resonator 1410 by the magnetic field. The induced current flows in the resonator 1410 in a clockwise direction. In this case, the induced current may transfer energy to the capacitor 1511 of the resonator 1510. In addition, a magnetic field is generated by the induced current. In FIG. 15A, the input current flowing through the feeding part 1420 and the resonator 1410 of FIG. 14 is indicated by a solid line, and the induced current flowing through the resonator 1410 is indicated by a dotted line.

The direction of the magnetic field generated by the current can be known through the law of the right-hand screw. Inside the feeding part 1420 of FIG. 14, the direction 1521 of the magnetic field generated by the input current flowing through the feeding part 1420 and the direction 1523 of the magnetic field generated by the induced current flowing through the resonator 1410 are the same as each other. Do. Accordingly, the strength of the magnetic field in the feeding unit 1420 is enhanced.

In addition, in the region between the feeding unit 1420 and the resonator 1410, a direction 1533 of a magnetic field generated by an input current flowing through the feeding unit 1420 and a direction of a magnetic field generated by an induced current flowing through the resonator 1410 (1531) are in opposite phases to each other. Accordingly, in the region between the feeding part 1420 and the resonator 1410, the strength of the magnetic field is weakened.

In a loop-type resonator, the strength of the magnetic field is generally weak at the center of the resonator, and the strength of the magnetic field is strong at the outer portion of the resonator. However, referring to FIG. 15A, the feeding part 1420 is electrically connected to both ends of the capacitor 1411 of the resonator 1410, so that the direction of the induced current of the resonator 1410 and the input current of the feeding part 1420 The direction of becomes the same. Since the direction of the induced current of the resonator 1410 and the direction of the input current of the feeding unit 1420 are the same, the strength of the magnetic field is strengthened inside the feeding unit 1420 and the magnetic field is increased outside the feeding unit 1420. The strength weakens. As a result, the strength of the magnetic field may be strengthened at the center of the loop-shaped resonator 1410 due to the feeding part 1420, and the strength of the magnetic field may be weakened at the outer part of the resonator 1410. Therefore, the strength of the magnetic field as a whole may be uniform inside the resonator 1410.

Meanwhile, since the efficiency of power transmission transmitted from the source resonator to the target resonator is proportional to the strength of the magnetic field generated from the source resonator, the power transmission efficiency may also increase as the strength of the magnetic field at the center of the source resonator increases.

Referring to FIG. 15B, the feeding unit 1540 and the resonator 1550 may be expressed as an equivalent circuit. The input impedance Zin seen when looking at the resonator side from the feeding unit 1540 can be calculated as follows.

Here, M refers to the mutual inductance between the feeding part 1540 and the resonator 1550, ω refers to the resonance frequency between the feeding part 1540 and the resonator 1550, and Z refers to the target device in the resonator 1550. It can mean the impedance seen when looking to the side. Zin can be proportional to the mutual inductance M. Accordingly, Zin can be controlled by adjusting mutual inductance between the feeding unit 1540 and the resonator 1550. The mutual inductance M may be adjusted according to the area between the feeding part 1540 and the resonator 1550. The area between the feeding part 1540 and the resonator 1550 may be adjusted according to the size of the feeding part 1540. Since Zin may be determined according to the size of the feeding unit 1540, a separate matching network is not required to perform impedance matching with the output impedance of the power amplifier.

The resonator 1550 and the feeding unit 1540 included in the wireless power receiver may also have the distribution of the magnetic field as described above. The resonator 1550 included in the wireless power receiver may operate as a target resonator. The target resonator receives wireless power from the source resonator through magnetic coupling. In this case, an induced current may be generated in the target resonator through the received wireless power. The magnetic field generated by the induced current in the target resonator may generate the induced current again in the feeding unit 1540. In this case, when the resonator 1550 and the feeding unit 1540 are connected as in the structure of FIG. 15A, the direction of the current flowing from the resonator 1550 and the direction of the current flowing from the feeding unit 1540 become the same. Accordingly, the strength of the magnetic field may be enhanced inside the feeding part 1540, and the strength of the magnetic field may be weakened in a region between the feeding part 1540 and the resonator 1550.

16 shows an electric vehicle charging system according to an embodiment.

Referring to FIG. 16, the electric vehicle charging system 1600 includes a source system 1610, a source resonator 1620, a target resonator 1630, a target system 1640, and a battery 1650 for an electric vehicle.

The electric vehicle charging system 1600 has a structure similar to the wireless power transmission system of FIG. 1. That is, the electric vehicle charging system 1600 includes a source composed of a source system 1610 and a source resonator 1620. In addition, the electric vehicle charging system 1600 includes a target composed of a target resonator 1630 and a target system 1640.

In this case, the source system 1610 may include a variable SMPS (Variable SMPS), a power amplifier, a matching network, a control unit, and a communication unit, like the source 110 of FIG. 1. In this case, the target system 1640 may include a matching network, a rectifier, a DC/DC converter, a communication unit, and a control unit, like the target 120 of FIG. 1.

The electric vehicle battery 1650 may be charged by the target system 1640.

The electric vehicle charging system 1600 may use a resonant frequency of several KHz to several tens of MHz.

The source system 1610 may generate power according to the type of the charging vehicle, the capacity of the battery, and the state of charge of the battery, and supply the generated power to the target system 1640.

The source system 1610 may perform control for matching the alignment of the source resonator 1620 and the target resonator 1630. For example, when the source resonator 1620 and the target resonator 1630 are not aligned, the control unit of the source system 1610 may transmit a message to the target system 1640 to control alignment.

In this case, the case of misalignment may be a case in which the position of the target resonator 1630 is not at a position where magnetic resonance is maximized. That is, when the vehicle is not accurately stopped, the source system 1610 may guide the vehicle to adjust the position of the vehicle so that the source resonator 1620 and the target resonator 1630 may be aligned.

The source system 1610 and the target system 1640 may transmit and receive vehicle identifiers through communication, and may exchange various messages.

The contents described in FIGS. 2 to 15 may be applied to the electric vehicle charging system 1600. However, the electric vehicle charging system 1600 may use a resonance frequency of several KHz to several tens of MHz, and transmit power of several tens of watts or more to charge the battery 1650 for an electric vehicle.

The wireless power transmission apparatus according to an embodiment adjusts at least one of a voltage intensity, a voltage phase, a current intensity, and a current phase of power supplied to the resonator, so that the number of devices to be charged, the location of the device to be charged, and a source resonator. Optimal power transmission efficiency can be maintained even in various environments such as a change in distance and position between the and target resonators.

The apparatus for transmitting power wirelessly according to an embodiment may control at least one of a voltage intensity, a voltage phase, a current intensity, and a current phase of power supplied to the resonator to control the magnetic field generated by the resonator.

The apparatus for transmitting power wirelessly according to an embodiment may be applied even when the location of a source or a target can be moved. For example, during wireless charging of an electric vehicle, power transmission efficiency can be maintained even when the source resonator and the target resonator are not aligned with each other.

The wireless power transmission apparatus according to an embodiment may reduce the number of matching networks by adjusting at least one of a voltage intensity, a voltage phase, a current intensity, and a current phase of power supplied to the resonator.

The apparatus described above may be implemented as a hardware component, a software component, and/or a combination of a hardware component and a software component. For example, the devices and components described in the embodiments include, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable array (FPA), It may be implemented using one or more general purpose or special purpose computers, such as a programmable logic unit (PLU), a microprocessor, or any other device capable of executing and responding to instructions. The processing device may execute an operating system (OS) and one or more software applications executed on the operating system. Further, the processing device may access, store, manipulate, process, and generate data in response to the execution of software. For the convenience of understanding, although it is sometimes described that one processing device is used, one of ordinary skill in the art, the processing device is a plurality of processing elements and/or a plurality of types of processing elements. It can be seen that it may include. For example, the processing device may include a plurality of processors or one processor and one controller. In addition, other processing configurations are possible, such as a parallel processor.

The software may include a computer program, code, instructions, or a combination of one or more of these, configuring the processing unit to operate as desired or processed independently or collectively. You can command the device. Software and/or data may be interpreted by a processing device or, to provide instructions or data to a processing device, of any type of machine, component, physical device, virtual equipment, computer storage medium or device. , Or may be permanently or temporarily embodyed in a transmitted signal wave. The software may be distributed over networked computer systems and stored or executed in a distributed manner. Software and data may be stored on one or more computer-readable recording media.

The method according to the embodiment may be implemented in the form of program instructions that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, etc. alone or in combination. The program instructions recorded on the medium may be specially designed and configured for the embodiment, or may be known and usable to those skilled in computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic media such as floptical disks. -A hardware device specially configured to store and execute program instructions such as magneto-optical media, and ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine language codes such as those produced by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like. The hardware device described above may be configured to operate as one or more software modules to perform the operation of the embodiment, and vice versa.

As described above, although the embodiments have been described by the limited embodiments and drawings, various modifications and variations are possible from the above description to those of ordinary skill in the art. For example, the described techniques are performed in a different order from the described method, and/or components such as systems, structures, devices, circuits, etc. described are combined or combined in a form different from the described method, or other components Alternatively, even if substituted or substituted by an equivalent, an appropriate result can be achieved.

Therefore, other implementations, other embodiments, and those equivalent to the claims also fall within the scope of the claims to be described later.

Claims (20)

In the wireless power transmission device,
A plurality of resonators for wirelessly transmitting first power to the wireless power receiving apparatus;
A controller for controlling at least one of a voltage magnitude and a current magnitude of the second power supplied to the at least one resonator; And
A feeding unit that supplies the second power to the at least one resonator
Including,
The control unit,
In a wireless charging area of the wireless power transmission device, at least one of a distance, a direction, and an angle between the wireless power transmission device and the wireless power reception device is obtained, and
Adjusting at least one of the voltage intensity and the current intensity of the second power based on at least one of the distance, the direction, and the angle between the wireless power transmitter and the wireless power receiver,
The resonators include a plurality of planes orthogonal to each other and a plane parallel to each other,
Wireless power transmission device. The method of claim 1,
The control unit,
Obtaining the number of wireless power receiving devices to be charged in the wireless charging area,
Adjusting at least one of the voltage strength and the current strength of the second power further based on the number of wireless power receiving devices to be charged,
Wireless power transmission device. The method of claim 1,
The control unit,
Acquiring information about a location change of the wireless power receiving device in the wireless charging area,
Adjusting at least one of the voltage intensity and the current intensity of the second power further based on information on a position change of the wireless power receiving device,
Wireless power transmission device. The method of claim 1,
The control unit
Calculating an impedance of the N port network between the resonators connected to the N port network and other resonators connected to the N port network,
Controlling at least one of the voltage intensity and the current intensity of the second power further based on the impedance
Wireless power transmission device. The method of claim 1,
The resonators are coupled to each other or separated from each other,
The feeding part includes an inductor,
Wireless power transmission device. The method of claim 1,
The control unit
Sequentially changing at least one of the voltage intensity and the current intensity of the second power within at least one of the voltage intensity and the current intensity that can be applied by the feeding unit
Wireless power transmission device. The method of claim 1,
The control unit
Randomly changing at least one of the voltage intensity and the current intensity of the second power within at least one of the voltage intensity and the current intensity that can be applied by the feeding unit
Wireless power transmission device. The method of claim 1,
The control unit
Changing at least one of the voltage intensity and the current intensity of the second power based on a lookup table within at least one of the voltage intensity and the current intensity that can be applied by the feeding unit
Wireless power transmission device. The method of claim 1,
Each of the resonators
A first transmission line including a first signal conductor portion, a second signal conductor portion, and a first ground conductor portion corresponding to the first signal conductor portion and the second signal conductor portion;
A first conductor connecting the first signal conductor portion and the first ground conductor portion;
A second conductor connected to the second signal conductor portion; And
A first capacitor inserted between the first signal conductor portion and the second signal conductor portion in series with respect to a current flowing through the first signal conductor portion and the second signal conductor portion
Wireless power transmission device comprising a. The method of claim 1,
The resonators are
a first resonator including a plane parallel to the xy plane;
a second resonator including a plane parallel to the yz plane; And
a third resonator with a plane parallel to the zx plane
Wireless power transmission device comprising a. In the wireless power transmission device,
A plurality of resonators for transmitting first power to the wireless power receiving apparatus;
A controller for controlling at least one of a voltage phase and a current phase of the second power supplied to the at least one resonator; And
A feeding unit that supplies the second power to the at least one resonator
Including,
The control unit,
In a wireless charging area of the wireless power transmission device, at least one of a distance, a direction, and an angle between the wireless power transmission device and the wireless power reception device is obtained, and
Adjusting at least one of the voltage phase and the current phase of the second power based on at least one of the distance, the direction, and the angle between the wireless power transmitter and the wireless power receiver,
The resonators include a plurality of planes orthogonal to each other and a plane parallel to each other,
Wireless power transmission device. The method of claim 11,
The control unit,
Obtaining the number of wireless power receiving devices to be charged in the wireless charging area,
Adjusting at least one of the voltage phase and the current phase of the second power further based on the number of wireless power receiving devices to be charged,
Wireless power transmission device. The method of claim 11,
The control unit,
Acquiring information about a location change of the wireless power receiving device in the wireless charging area,
Adjusting at least one of the voltage phase and the current phase of the second power further based on information on the position change of the wireless power receiving device,
Wireless power transmission device. The method of claim 11,
The control unit
Calculate an impedance of the N port network between the resonators connected to the N port network and other resonators connected to the N port network,
Controlling at least one of the voltage phase and the current phase of the second power further based on the impedance
Wireless power transmission device. The method of claim 11,
The resonators are
a first resonator including a plane parallel to the xy plane;
a second resonator including a plane parallel to the yz plane; And
a third resonator with a plane parallel to the zx plane
Wireless power transmission device comprising a. A method of operating a wireless power transmission device comprising a plurality of resonators for wirelessly transmitting first power to a wireless power receiving device and a feeding unit for supplying second power to at least one resonator,
Controlling at least one of a voltage intensity, a voltage phase, a current intensity, and a current phase of the second power supplied to the at least one resonator
Including,
The controlling step,
Acquiring at least one of a distance, a direction, and an angle between the wireless power transmitter and the wireless power receiver in a wireless charging area of the wireless power transmitter; And
At least one of the voltage intensity, the voltage phase, the current intensity, and the current phase of the second power based on at least one of the distance, the direction, and the angle between the wireless power transmitter and the wireless power receiver. Steps to adjust
Including,
The method of operating a wireless power transmission apparatus, wherein the resonators include a plurality of planes orthogonal to each other and a plane parallel to each other. The method of claim 16,
The controlling step
Acquiring the number of wireless power receiving devices to be charged in the wireless charging area
Including more,
The adjusting step
Adjusting at least one of the voltage strength and the current strength of the second power further based on the number of wireless power receiving devices to be charged in the wireless charging area
Containing,
How to operate a wireless power transmission device. The method of claim 16,
The controlling step
Obtaining information on a change in the location of the wireless power receiving device in the wireless charging area
Including more,
The adjusting step
Adjusting at least one of the voltage intensity and the current intensity of the second power further based on information on a position change of the wireless power receiving device
Containing,
How to operate a wireless power transmission device. The method of claim 16,
The controlling step
Calculating an impedance of the N port network between the resonators connected to the N port network and other resonators connected to the N port network
Including more,
The adjusting step
Adjusting at least one of the voltage intensity and the current intensity of the second power further based on the impedance
Containing,
How to operate a wireless power transmission device. A computer-readable recording medium on which a program for executing the method of any one of claims 16 to 19 is recorded.

Images