KR101930801B1 - Method and apparatus for detecting efficiency of wireless power transmission - Google Patents

Abstract

A method and apparatus are provided for measuring the efficiency of a wireless power transmission. The output power of the source device is adjusted based on the current flowing in the power conversion section of the source device. The wireless power transmission efficiency is calculated based on the adjusted output power and the power required by the target device. Further, when the information generated based on the power received by the target device is transmitted to the source device, the source device calculates the wireless power transmission efficiency based on the output power and the transmitted information.

Description

[0001] METHOD AND APPARATUS FOR DETECTING EFFICIENCY OF WIRELESS POWER TRANSMISSION [0002]

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

A method and apparatus for detecting the efficiency of wireless power transmission is disclosed.

Wireless power refers to the energy delivered from a wireless power transmission device to a wireless power reception device through magnetic coupling. Thus, a wireless power charging system includes a source device that wirelessly transmits power and a target device that wirelessly receives power. At this time, the source device may be referred to as a wireless power transmission device. The target device may also be referred to as a wireless power receiving device.

The source device has a source resonator, and the target device has a target resonator. A magnetic coupling or a resonant coupling may be formed between the source resonator and the target resonator.

One source device may transmit power to a plurality of target devices.

When a plurality of target devices are simultaneously accessed into the resonator region of the source device or when power is applied to the source device when a plurality of target devices are present in the resonator region of the source device, Data collision occurs by the devices, and a normal charging operation may not be performed.

One embodiment of the present invention can provide an apparatus and method for adjusting the output power based on the current flowing in the power conversion unit and calculating the wireless power efficiency based on the adjusted output power.

An embodiment of the present invention may provide an apparatus and method for calculating wireless power efficiency using information generated based on power received by a target device.

According to an aspect of the present invention, there is provided a method of detecting a wireless power transmission efficiency to a target device, the method comprising: determining an initial value of output power based on first information on a required power of the target device; Transmitting an output power corresponding to an initial value to the target device, detecting the current of the output power, adjusting the output power based on the detected current, and outputting the adjusted output power and the information And calculating the wireless power transmission efficiency based on the calculated power level.

The wireless power transmission efficiency detection method may further include receiving second information on the required power from the target device.

The wireless power transmission efficiency detection method may further include receiving information on the power received by the target device from the target device.

The radio power transmission efficiency may be calculated based on the received power information and the adjusted output power.

The adjusting the output power may include increasing the output power until the output current becomes constant when the detected current increases.

The wireless power transmission efficiency detection method may further include stopping the operation of the source device when the calculated wireless power transmission efficiency is lower than the reference efficiency.

According to another aspect of the present invention, there is provided a method for controlling a target device, the method comprising: determining an initial value of output power based on first information on a power required by the target device; Receiving from the target device second information generated based on the power received by the target device, calculating the wireless power transmission efficiency based on the second information and the output power, An efficiency detection method is provided.

The second information may be information on power flowing to the virtual load of the target device.

The second information may be information on a current flowing in the target device in a state in which the path to the load of the target device is blocked.

The wireless power transmission efficiency detection method may further include adjusting the output power based on the second information.

The step of adjusting the output power may be repeatedly performed until the power received by the target device reaches the power required by the target device.

The wireless power transmission efficiency detection method may further include stopping the operation of the source device when the calculated wireless power transmission efficiency is lower than the reference efficiency.

According to another aspect of the present invention, there is provided a control method for a power management system including a control unit for determining an initial value of output power based on information about a power required for a target device, a resonator for transmitting output power according to the initial value to the target device, Wherein the controller adjusts the output power based on the detected current and calculates the wireless power transmission efficiency based on the adjusted output power and the information, A transmission device is provided.

The control unit may receive information on the required power from the target device.

The controller receives information on the power received by the target device from the target device, and calculates the transmission power efficiency based on the received power information and the adjusted output power.

The control unit may adjust the output power by increasing the output power until the output current becomes constant when the detected current increases.

The control unit may stop the operation of the source device when the calculated radio power transmission efficiency is lower than the reference efficiency.

According to another aspect of the present invention, there is provided a control method for a power management system, comprising: a control unit for determining an initial value of output power based on first information about a power required by a target device; and a resonator for transmitting output power according to the initial value to the target device Wherein the control unit receives second information generated based on the power received by the target device from the target device and calculates the wireless power transmission efficiency based on the second information and the output power, A power transmission device is provided.

The control unit adjusts the output power based on the second information, and the control unit may repeatedly perform the adjustment until the power received by the target device reaches a power required by the target device.

The control unit may stop the operation of the source device when the calculated radio power transmission efficiency is lower than the reference efficiency.

The control unit may stop the operation of the source device when the current is equal to or greater than a predetermined value. The set value may be determined based on the wireless power transmission efficiency and the output power.

There is provided an apparatus and method for adjusting output power based on a current flowing in a power conversion unit and calculating wireless power efficiency based on the adjusted output power.

An apparatus and method for calculating wireless power efficiency using information generated based on power received by a target device are provided.

1 illustrates a wireless power transmission and charging system in accordance with one embodiment.
Figure 2 shows the distribution of the magnetic field in the resonator and feeder according to one embodiment.
3 is a view showing a configuration of a resonator and a feeder according to one embodiment.
4 is a view showing a distribution of a magnetic field in a resonator according to feeding of a feeding part according to an embodiment.
5 illustrates a multi-target device communication environment according to one example.
6 illustrates modes of a wireless power transmission and charging system according to an example.
7 is a structural diagram of a source device according to an embodiment.
8 is a structural diagram of a target device according to an embodiment.
9 is a flowchart of a power control method of a wireless power transmission and charging system according to an embodiment.
Figure 11 illustrates the maximum efficiency point according to one embodiment.
12 is a flow diagram of a method for detecting efficiency of a wireless power transmission in accordance with one embodiment.
13 illustrates a method for detecting the change in efficiency between resonators according to an example.
14 shows the adjustment of the PA power according to an example.
15 shows the fixing of the PA current according to an example.
FIG. 16 illustrates a case where power transmission is interrupted by a low radio power transmission efficiency according to an example.
17 is a flow diagram of a method for detecting the efficiency of a wireless power transmission using a virtual load according to an embodiment.
Figure 18 illustrates the connection of a virtual load according to an example.
FIG. 19 illustrates path selection using an SPDT switch according to an example.
20 is a flow diagram of a method for detecting efficiency of a wireless power transmission using load modulation in accordance with one embodiment.
FIG. 21 illustrates a load modulator power detection method according to an example.
22 is a flow diagram of a method for detecting efficiency of a wireless power transmission based on received power of a target device according to an embodiment.
FIG. 23 illustrates power control based on received power according to an example.
24 illustrates over power control according to an example.
25 shows an electric vehicle charging system according to an embodiment.
26 and 27 show applications in which a wireless power receiving apparatus and a wireless power transmission apparatus according to an embodiment can be installed.
28 shows a configuration example of a wireless power transmission apparatus wireless power receiving apparatus according to an embodiment.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to or limited by the embodiments. Like reference symbols in the drawings denote like elements.

1 illustrates a wireless power transmission and charging system in accordance with one embodiment.

Referring to FIG. 1, a wireless power transmission and charging system according to one embodiment includes a source device 110 and a target device 120.

The target device 120 may be any one of a portable terminal, a notebook, a television, various electromagnetic devices, a hearing aid, and an electric vehicle. That is, the target device 120 may be mounted on any one of a portable terminal, a notebook, a television, various electromagnetic devices, a hearing aid, and an electric vehicle.

The source device 110 may include an AC / DC converter 111, a power detector 113, a power conversion unit 114, a control and communication unit 115, and a source resonator 116.

The target device 120 may include a target resonator 121, a rectification section 122, a DC / DC converter 123, a switch section 124, a charging section 125, and a control and communication section 126.

The AC / DC converter 111 rectifies an AC voltage of several tens Hz band outputted from a power supply 112 to generate a DC voltage. The AC / DC converter 111 can output a DC voltage of a certain level or adjust the output level of the DC voltage according to the control of the control and communication unit 115. [

The power detector 113 detects the output current and voltage of the AC / DC converter 111 and transmits information on the detected current and voltage to the control and communication unit 115. The power detector 113 may also detect the input current and voltage of the power conversion unit 114. [

The power conversion unit 114 can generate power by converting a DC voltage of a certain level into an AC voltage by using a matching pulse signal of several KHz to several tens MHz. That is, the power conversion section 114 converts the DC voltage supplied to the power amplifying section into the AC voltage using the reference resonance frequency F _Ref , thereby generating the communication power or the charging power used in the plurality of target devices have. Here, the communication power may mean a small power of 0.1 to 1 mWatt, and the charging power may mean a large power of 1 mWatt to 200 Watt consumed in the device load of the target device. As used herein, the term " charging " may be used to mean powering a unit or element charging power. The term " charging " may also be used to mean powering a unit or element that consumes power. Here, the unit or element includes, for example, a battery, a display, a sound output circuit, a main processor, and various sensors.

In the present specification, the " reference resonance frequency " can be used to mean a resonance frequency that the source device 110 basically uses. Also, the " tracking frequency " can be used to mean a resonance frequency adjusted according to a preset method.

The control and communication unit 115 detects reflected waves for the "communication power" or the "charging power", and performs mismatching between the target resonator 121 and the source resonator 116 based on the detected reflected waves. . The control and communication unit 115 can detect mismatching by detecting the envelope of the reflected wave, and can detect mismatching by detecting the amount of power of the reflected wave. The control and communication unit 115 can calculate the voltage standing wave ratio (VSWR) based on the level of the output voltage of the source resonator 116 or the power conversion unit 114 and the voltage level of the reflected wave, If the voltage standing wave ratio is smaller than the predetermined value, it can be determined that the mismatching has been detected. If the voltage standing wave ratio is smaller than the predetermined value, the control and communication unit 115 may calculate the power transmission efficiency for each of the predetermined N tracking frequencies. If the power transmission efficiency among the N tracking frequencies is the best, F _Best can be determined, and the F _Ref can be adjusted to the F _Best .

Also, the control and communication unit 115 can adjust the frequency of the switching pulse signal. The frequency of the switching pulse signal can be determined by the control and communication unit 115. The control and communication unit 115 can generate the modulation signal for transmission to the target device 120 by controlling the power conversion unit 114. [ In other words, the control and communication unit 115 can transmit various messages to the target device through the in-band communication. In addition, the control and communication unit 115 can detect the reflected wave, It is possible to demodulate a signal received from the base station.

The control and communication unit 115 may generate a modulated signal for performing in-band communication through various methods. The control and communication unit 115 can generate a modulated signal by turning on / off the switching pulse signal. Also, the control and communication unit 115 can perform delta-sigma modulation to generate a modulated signal. The control and communication unit 115 can generate a pulse width modulation signal having a constant envelope.

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

The source resonator 116 transfers the electromagnetic energy to the target resonator 121. That is, the source resonator 116 can transmit " communication power " or " charging power " to the target device 120 through magnetic coupling with the target resonator 121.

The target resonator 121 receives electromagnetic energy from the source resonator 116. That is, the target resonator 121 may receive " communication power " or " charging power " from the source device 110 through magnetic coupling with the source resonator 116. In addition, the target resonator 121 may receive various messages from the source device via in-band communication.

The rectifying unit 122 rectifies the AC voltage to generate a DC voltage. That is, the rectifying section 122 can rectify the received AC voltage to the target resonator 121. [

The DC / DC converter 123 adjusts the level of the DC voltage output from the rectifying unit 122 to match the capacity of the charger 125. For example, the DC / DC converter 123 can adjust the level of the DC voltage output from the rectifying unit 122 to 3 to 10 Volts.

The switch unit 124 is turned on / off under the control of the control and communication unit 126. When the switch unit 124 is turned off, the control and communication unit 115 of the source device 110 detects the reflected wave. That is, when the switch portion 124 is turned off, the magnetic coupling between the source resonator 116 and the target resonator 121 can be removed.

The charging unit 125 may include a battery. The charging unit 125 can charge the battery using the DC voltage output from the DC / DC converter 123. [

The control and communication unit 126 may perform in-band communication for transmitting and receiving data using a resonant frequency. The control and communication unit 126 may detect a signal between the target resonator 121 and the rectifying unit 122 and demodulate the received signal or detect the output signal of the rectifying unit 122 to demodulate the received signal. That is, the control and communication unit 126 can demodulate the received message through the in-band communication. Further, the control and communication section can modulate the signal to be transmitted to the source device 110 by adjusting the impedance of the target resonator 121. [ The control and communication unit may also modulate a signal to be transmitted to the source device 110 through on / off of the switch unit 124. [ In a simple example, the control and communication unit 126 may increase the impedance of the target resonator 121 so that the reflected wave is detected in the control and communication unit 115 of the source device 110. Depending on whether or not the reflected wave is generated, the control and communication unit 115 of the source device 110 can detect the binary number " 0 " or " 1 ".

The control and communication unit 126 stores the type of the target device, the manufacturer information of the target device, the model name of the target device, the battery type of the target device, Quot ;, " information on the characteristics of the target resonator of the target device ", " information on the used frequency band of the target device ", " amount of power consumed by the target device & A unique identifier of the target device, or a version or standard information of the target device of the target device to the wireless power transmission apparatus.

Meanwhile, the control and communication unit 126 may perform out-band communication using a communication channel. The control and communication unit 126 may include a communication module such as Zigbee or Bluetooth. The control and communication unit 126 may transmit and receive data to and from the source device 110 through out-band communication.

The control and communication unit 126 receives the wake-up request message from the wireless power transmission apparatus, detects the amount of power received by the target resonator, and transmits information about the amount of power received by the target resonator to the wireless power transmission Device. Here, the information on the amount of power received by the target resonator is " input voltage value and current value of the rectifying section 122 ", " output voltage value and current value of the rectifying section 122 & 123) output voltage value and current value ".

In FIG. 1, the control and communication unit 115 may set the resonance bandwidth of the source resonator 116. Depending on the setting of the resonance bandwidth of the source resonator 116, the Q-factor Q _S of the source resonator 116 can be determined.

In addition, the control and communication unit 126 may set the resonance bandwidth of the target resonator 121. The Q-factor of the target resonator 121 can be determined according to the setting of the resonance bandwidth of the target resonator 121. [ At this time, the resonant bandwidth of the source resonator 116 may be set to be wider or narrower than the resonant bandwidth of the target resonator 121. Through communication, the source device 110 and the target device 120 can share information about the resonant bandwidth of the source resonator 116 and the target resonator 121, respectively. The Q-factor Q _S of the source resonator 116 may be set to a value greater than 100 when a higher power is required from the target device 120 than the reference value. In addition, when a lower power than the reference value is required from the target device 120, the Q-factor Q _S of the source resonator 116 can be set to a value smaller than 100.

In a resonant mode wireless power transmission, the resonant bandwidth is an important factor. Qt is a Q-factor that takes into consideration both a change in distance between the source resonator 116 and the target resonator 121, a change in resonant impedance, an impedance mismatching, a reflection signal, etc. Qt is expressed by Equation 1, Inverse relationship.

는 대역폭,

는 공진기 사이의 반사 손실, BWS는 소스 공진기(116)의 공진 대역폭, BWD는 타겟 공진기(121)의 공진 대역폭을 나타낸다.In Equation (1), f ₀ is the center frequency,

Bandwidth,

BWS is the resonant bandwidth of the source resonator 116, and BWD is the resonant bandwidth of the target resonator 121. [

On the other hand, in the wireless power transmission, the efficiency U of the wireless power transmission can be defined as shown in Equation (2).

는 소스 공진기(115)에서의 반사계수,

는 타겟 공진기(121)에서의 반사계수,

는 공진 주파수, M은 소스 공진기(116)와 타겟 공진기(121) 사이의 상호 인덕턴스, R_S는 소스 공진기(116)의 임피던스, R_D는 타겟 공진기(121)의 임피던스, Q_S는 소스 공진기(116)의 Q-factor, Q_D는 타겟 공진기(121)의 Q-factor, Q_K는 소스 공진기(116)와 타겟 공진기(121) 사이의 에너지 커플링에 대한 Q-factor이다. Where K is the coupling coefficient for the energy coupling between the source resonator 115 and the target resonator 121,

Is the reflection coefficient at the source resonator 115,

The reflection coefficient at the target resonator 121,

Is the resonant frequency, M is the source resonator 116 and the target resonator 121, the impedance of the mutual inductance, R _S is the source resonator 116 between, R _D is the impedance of the target cavity 121, Q _S is the source resonator ( 116) Q-factor, Q _D of the Q-factor, Q _K of the target cavity 121 is a Q-factor of the energy coupling between the source resonator 116 and the target resonator 121. the

Referring to Equation 2, the Q-factor is highly related to the efficiency of the wireless power transmission.

Therefore, the Q-factor is set to a high value in order to increase the efficiency of the wireless power transmission. At this time, when Q _S and Q _D are set to an excessively high value, a change in coupling coefficient K for energy coupling, a change in distance between the source resonator 116 and the target resonator 121, a change in resonance impedance, The efficiency of the wireless power transmission may decrease due to matching or the like.

Also, if the resonance bandwidth of each of the source resonator 116 and the target resonator 121 is set too narrow to increase the efficiency of the wireless power transmission, impedance mismatching and the like can easily occur even with a small external influence. Considering impedance mismatch, Equation (1) can be expressed as Equation (3).

When the resonance bandwidth or the bandwidth of the impedance matching frequency between the source resonator 115 and the target resonator 121 is maintained in an unbalance relationship, A decrease in the efficiency of the wireless power transmission due to a change in distance, a change in resonance impedance, impedance mismatch, or the like can be reduced. According to Equations (1) and (3), if the resonance bandwidth between the source resonator 116 and the target resonator 121 or the bandwidth of the impedance matching frequency is maintained in an unbalance relationship, the cue- The unbalance relationship between the cue-effectors of the target resonator 121 is maintained.

In Figs. 2 to 4, " resonator " includes a source resonator and a target resonator.

Figure 2 shows the distribution of the magnetic field in the resonator and feeder according to one 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. 2 (a), a magnetic field 230 is generated as the input current flows in the feeder 210. The direction 231 of the magnetic field in the feeder 210 and the direction 233 of the magnetic field in the outside have opposite phases to each other. An induced current is generated in the resonator 220 by the magnetic field 230 generated in the feeder 210. The direction of the induced current is opposite to the direction of the input current.

A magnetic field 240 is generated in the resonator 220 by an induced current. The direction of the magnetic field has the same direction inside the resonator 220. Therefore, the direction 241 of the magnetic field generated inside the feeder 210 by the resonator 220 and the direction 243 of the magnetic field generated from the outside of the feeder 210 have the same phase.

As a result, when the magnetic field generated by the feeder 210 and the magnetic field generated by the resonator 220 are combined, the strength of the magnetic field is weakened inside the feeder 210, do. Therefore, when power is supplied to the resonator 220 through the feeder 210 having the structure as shown in FIG. 2, the intensity of the magnetic field at the center of the resonator 220 is weak, and the strength of the magnetic field at the periphery is strong. If the distribution of the magnetic field on the resonator 220 is not uniform, it is difficult to perform the impedance matching because the input impedance varies from time to time. In addition, since the wireless power transmission is good in the portion where the magnetic field strength is strong and the wireless power transmission is not performed in the portion where the strength of the magnetic field is weak, the power transmission efficiency is decreased on average.

3 is a view showing a configuration of a resonator and a feeder according to one embodiment.

Referring to FIG. 3 (a), the resonator 310 may include a capacitor 311. The feeding portion 320 may be electrically connected to both ends of the capacitor 311. [

(b) is a diagram more specifically showing the structure of (a). At this time, the resonator 310 may include a first transmission line, a first conductor 341, a second conductor 342, and at least one first capacitor 350.

A first capacitor 350 is inserted in series between the first signal conductor portion 331 and the second signal conductor portion 332 in the first transmission line such that the electric field is applied to the first capacitor 350). Generally, the transmission line includes at least one conductor at the top and at least one conductor at the bottom, where current flows through the conductor at the top and the conductor at the bottom is electrically grounded. In this specification, the conductor on the upper part of the first transmission line is divided into the first signal conductor part 331 and the second signal conductor part 332, and the conductor under the first transmission line is called the first ground conductor part 333).

(b), the resonator may have the form of a two-dimensional structure. The first transmission line includes a first signal conductor portion 331 and a second signal conductor portion 332 at an upper portion thereof and a first ground conductor portion 333 at a lower portion thereof. The first signal conductor portion 331 and the second signal conductor portion 332 and the first ground conductor portion 333 are disposed facing each other. The current flows through the first signal conductor portion 331 and the second signal conductor portion 332.

One end of the first signal conductor portion 331 is shorted to the first conductor 341 and the other end is connected to the first capacitor 350 as shown in FIG. One end of the second signal conductor portion 332 is grounded to the second conductor 342 and the other end is connected to the first capacitor 350. As a result, the first signal conductor portion 331, the second signal conductor portion 332 and the first ground conductor portion 333, and the conductors 341 and 342 are connected to each other so that the resonator has an electrically closed loop structure . Here, the 'loop structure' includes a circular structure, a polygonal structure such as a rectangle, and the like, and the term 'having a loop structure' means that it is electrically closed.

The first capacitor 350 is inserted in the middle of the transmission line. More specifically, a first capacitor 350 is inserted between the first signal conductor portion 331 and the second signal conductor portion 332. In this case, the first capacitor 350 may have the form of a lumped element and a distributed element. In particular, a dispersed capacitor in the form of a dispersive element can comprise zigzag shaped conductor lines and a dielectric with a high dielectric constant present between the conductor lines.

As the first capacitor 350 is inserted into the transmission line, the source resonator may have the characteristics of a metamaterial. Here, a metamaterial is a material having a special electrical property that can not be found in nature, and has an artificially designed structure. The electromagnetic properties of all materials present in nature have inherent permittivity or permeability, and most materials have a positive permittivity and a positive permeability.

In most materials, the right-hand rule applies to electric fields, magnetic fields and pointing vectors, so these materials are called RHM (Right Handed Material). However, the meta-material is a material having a permittivity or permeability that does not exist in the natural world, and may be an epsilon negative material, an MNG (mu negative material), a DNG (double negative) material, index material, left-handed material, and the like.

At this time, when the capacitance of the first capacitor 350 inserted as a lumped element is properly determined, the source resonator can have a metamaterial characteristic. In particular, by appropriately adjusting the capacitance of the first capacitor 350, the source resonator can have a negative permeability, so that the source resonator can be called an MNG resonator. The criterion for determining the capacitance of the first capacitor 350 may vary. A criterion allowing the source resonator to have the property of a metamaterial, a premise that the source resonator has a negative permeability at the target frequency, or a source resonator having a Zeroth-Order Resonance characteristic And the capacitance of the first capacitor 350 can be determined under the premise of at least one of the above-mentioned premises.

The MNG resonator may have a zeroth-order resonance characteristic with a resonant frequency at a frequency of zero propagation constant. Since the MNG resonator may have a zero resonance characteristic, the resonance frequency may be independent of the physical size of the MNG resonator. That is, as will be described later, it is sufficient to appropriately design the first capacitor 350 in order to change the resonant frequency in the MNG resonator, so that the physical size of the MNG resonator can be changed.

Also, since the electric field in the near field is concentrated in the first capacitor 350 inserted in the transmission line, the magnetic field in the near field is dominant due to the first capacitor 350. Since the MNG resonator can have a high Q-factor by using the first capacitor 350 of the lumped element, the power transmission efficiency can be improved. For reference, the queue-factor represents the ratio of the reactance to the degree of resistance or ohmic loss in the wireless power transmission, the larger the queue-factor, the greater the efficiency of the wireless power transmission .

Further, although not shown in (b), a magnetic core passing through the MNG resonator may be further included. Such a magnetic core can perform a function of increasing a power transmission distance.

the feeder 320 may include a second transmission line, a third conductor 371, a fourth conductor 372, a fifth conductor 381, and a sixth conductor 382 .

The second transmission line includes a third signal conductor portion 361 and a fourth signal conductor portion 362 at the top and a second ground conductor portion 363 at the bottom. The third signal conductor portion 361 and the fourth signal conductor portion 362 and the second ground conductor portion 363 are disposed facing each other. The current flows through the third signal conductor portion 361 and the fourth signal conductor portion 362.

One end of the third signal conductor portion 361 is shorted to the third conductor 371 and the other end is connected to the fifth conductor 381 as shown in FIG. One end of the fourth signal conductor portion 362 is grounded to the fourth conductor 372, and the other end is connected to the sixth conductor 382. The fifth conductor 381 is connected to the first signal conductor portion 331 and the sixth conductor 382 is connected to the second signal conductor portion 332. The fifth conductor 381 and the sixth conductor 382 are connected in parallel at both ends of the first capacitor 350. At this time, the fifth conductor 381 and the sixth conductor 382 may be used as an input port for receiving an RF signal.

As a result, the third signal conductor portion 361, the fourth signal conductor portion 362 and the second ground conductor portion 363, the third conductor 371, the fourth conductor 372, the fifth conductor 381, The sixth conductor 382 and the resonator 310 are connected to each other so that the resonator 310 and the feeding portion 320 have an electrically closed loop structure. Here, the 'loop structure' includes a circular structure, a polygonal structure such as a rectangle, and the like. When an RF signal is input through the fifth conductor 381 or the sixth conductor 382, the input current flows to the feeding part 320 and the resonator 310, and the resonance is generated by the magnetic field generated by the input current. Gt; 310 < / RTI > The direction of the input current flowing in the feeding part 320 and the direction of the induced current flowing in the resonator 310 are formed to be the same so that the strength of the magnetic field is strengthened at the center of the resonator 310, Lt; / RTI >

Since the input impedance can be determined by the area of the region between the resonator 310 and the feeder 320, a separate matching network is not required to perform the matching of the input impedance with the output impedance of the power amplifier. Even when a matching network is used, the structure of the matching network can be simplified since the input impedance can be determined by adjusting the size of the feeding portion 320. [ A simple matching network structure minimizes the matching loss of the matching network.

The third conductor 371, the fourth conductor 372, the fifth conductor 381 and the sixth conductor 382 may have the same structure as the resonator 310. That is, when the resonator 310 has a loop structure, the feeding portion 320 may also have a loop structure. When the resonator 310 has a circular structure, the feeding portion 320 may have a circular structure.

4 is a view showing a distribution of a magnetic field in a resonator according to feeding of a feeding part according to an embodiment.

Feeding in a wireless power transmission implies supplying power to the source resonator. Also, in wireless power transmission, feeding can mean supplying AC power to the rectifying section. (a) shows the direction of the input current flowing in the feeding part and the direction of the induced current induced in the source resonator. (A) shows the direction of the magnetic field generated by the input current of the feeding portion and the direction of the magnetic field generated by the induced current of the source resonator. (a) is a more simplified representation of the resonator 410 and the feeder 420 of FIG. (b) shows an equivalent circuit of the feeding part and the resonator.

(a), the fifth conductor or the sixth conductor of the feeding portion can be used as the input port 410. The input port 410 receives an RF signal. The RF signal can be output from the 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 410 may be displayed in the form of an input current flowing in the feeding part. The input current flowing through the feeding section flows clockwise along the transmission line of the feeding section. However, the fifth conductor of the feeding portion is electrically connected to the resonator. More specifically, the fifth conductor is coupled to the first signal conductor portion of the resonator. Therefore, the input current flows not only in the feeding part but also in the resonator. In the resonator, the input current flows counterclockwise. A magnetic field is generated by an input current flowing in the resonator, and an induced current is generated in the resonator by the magnetic field. The induced current flows clockwise in the resonator. At this time, the induced current can transfer energy to the capacitor of the resonator. A magnetic field is generated by the induced current. (a), the input current flowing in the feeder and the resonator is indicated by a solid line, and the induced current flowing in the resonator is indicated by a dotted line.

The direction of the magnetic field generated by the current can be determined by the right-hand rule. The direction 421 of the magnetic field generated by the input current flowing in the feeding portion and the direction 423 of the magnetic field generated by the induced current flowing in the resonator are the same in the feeding portion. Thus, the intensity of the magnetic field inside the feeding portion is strengthened.

In the region between the feeding portion and the resonator, the direction 433 of the magnetic field generated by the input current flowing in the feeding portion and the direction 431 of the magnetic field generated by the induced current flowing in the source resonator are opposite in phase. Therefore, in the region between the feeding part and the resonator, the intensity of the magnetic field is weakened.

In a loop type resonator, the intensity of the magnetic field is generally weak at the center of the resonator and strong at the outer portion of the resonator. However, referring to (a), since the feeding portion is electrically connected to both ends of the capacitor of the resonator, the direction of the induced current of the resonator becomes the same as the direction of the input current of the feeding portion. Since the direction of the induced current of the resonator is the same as the direction of the input current of the feeding portion, the strength of the magnetic field is strengthened inside the feeding portion and the strength of the magnetic field outside the feeding portion is weakened. As a result, at the center of the loop-shaped resonator, the strength of the magnetic field is enhanced due to the feeding portion, and the strength of the magnetic field at the outer portion of the resonator is weakened. Therefore, the intensity of the magnetic field can be uniform throughout the resonator.

On the other hand, since the efficiency of the power transmission from the source resonator to the target resonator is proportional to the intensity of the magnetic field generated in the source resonator, the power transmission efficiency can be increased as the strength of the magnetic field is strengthened at the center of the source resonator.

(b), the feeding portion 440 and the resonator 450 may be represented by an equivalent circuit. The input impedance Z _{in, which} is seen when the resonator side is viewed in the feeding part 440, can be calculated by Equation (4).

Here, M denotes a mutual inductance between the feeding part 440 and the resonator 450, ω denotes a resonance frequency between the feeding part 440 and the resonator 450, Means the impedance seen when looking at the side. Z _in is proportional to the mutual inductance M. Therefore, Z _in can be controlled by adjusting the mutual inductance between the feeding portion 440 and the resonator 450. The mutual inductance M may be adjusted according to the area of the area between the feeding part 440 and the resonator 450. The area of the area between the feeding part 440 and the resonator 450 can be adjusted according to the size of the feeding part 440. Since Z _in can be determined according to the size of the feeding unit 440, a separate matching network is not required to perform impedance matching and impedance matching of the power amplifier.

The target resonator and the feeding portion included in the wireless power receiving apparatus may have a distribution of the magnetic field as described above. The target resonator receives radio power from the source resonator through magnetic coupling. At this time, an induced current can be generated in the target resonator through the received radio power. The magnetic field generated by the induced current in the target resonator can generate the induced current again in the feeding part. At this time, when the target resonator and the feeding portion are connected as in the structure of (a), the direction of the current flowing in the target resonator becomes the same as the direction of the current flowing in the feeding portion. Therefore, the strength of the magnetic field can be strengthened inside the feeding portion, and the strength of the magnetic field in the region between the feeding portion and the target resonator can be weakened.

5 illustrates a multi-target device communication environment according to one example.

The wireless power transmission and charging system 500 may include one source device 510 and one or more target devices 520.

One source device 510 may transmit power to a plurality of target devices 520. [

The source device 510 may be the source device 110 described above with reference to FIG. The target device 520 may be the target device 120 described above with reference to FIG.

The source device 510 may output an anti-collision data command and power.

The target devices 520 may have batteries.

When a plurality of target devices 520 simultaneously approach the resonator region of the source device 510 or when a plurality of target devices 520 are present in the resonator region of the source device 510, When the power is turned on, data collision may occur by a plurality of target devices 520 during the initial connection process. The normal charging operation may not be performed due to the collision.

6 illustrates modes of a wireless power transmission and charging system according to an example.

The wireless power transmission and charging system 500, in terms of software, can have three types of modes. The three types of modes may be a standby mode, a connection mode, and a transmission (charge) control mode.

(1) The standby mode means a state in which the target device 510 does not exist within the power transmission distance of the source device 510.

(2) The connection mode is a mode in which the source device 510 confirms the information such as 1) the type of the target device 510, the amount of power used, and the serial number through the initial connection between the source device 510 and the target device 510 And 2) the target device 510 is in a normal transfer (charge) control mode. The initial connection may occur when the target device 510 is present within the power transmission distance of the source device 510. [

In the connection mode, a plurality of target devices 520 can request a connection to one source device 510 at the same time. In the following embodiments, a method for always processing 1: 1 communication between the source device 510 and the target device 520 is performed when a plurality of target devices 510 simultaneously request a connection to the source device 510 Is described in detail.

(3) The transmission (charging) mode means a state in which the source device 510 and the target device 520 communicate with each other through a slot allocated by the source device 510 to the target device 520 in the connection mode.

On the side of the source device 510, the overall operation of the wireless power transmission and charging system 500 can be distinguished. For a single target device 520, the standby mode-connected mode-transfer (charge) mode-standby mode is repeated. 1 (source device 510) according to the following embodiments: In a wireless power transmission and charging system of N (target device 520), complex and repetitive operations may occur. For example, in a state where some target devices 520 among the plurality of target devices 520 are in the charging mode, some of the target devices 520 may have already completed charging, and the new target device 520 Connection can be attempted.

7 is a structural diagram of a source device according to an embodiment.

The source device 510 includes a control and communication section 710, a power supply 720, a power detector 730, an oscillator 740, a PA 750, a matching controller 755 and a source resonator (or TX resonator) 760).

The control and communication unit 710 may be a control and communication unit 115. The power supply 720 may be a power supply 112 and an AC / DC converter 111. The power detector 730 may be a power detector 113. The PA 750 may be a power conversion unit 114. The source resonator 760 may be a source resonator 116.

The control and communication unit 710 may include a power supply control unit 712. Alternatively, the source device 510 may further include a supply power control unit 712. The source device 510 may include a matching controller 755.

The oscillator 760 can generate a signal having a frequency in the range of several Khz to several tens MHz. The above signal may be the switching pulse signal described above with reference to Fig. The signal generated by the oscillator 760 may be applied to the PA 750. The oscillator 760 can change the frequency and the matching scheme of the signal. The control and communication unit 710 may control the oscillator 760 to change the frequency and matching scheme of the signal generated by the oscillator 760.

The power supply 720 may be a Switching Mode Power Supply. The power supply control unit 712 can control the power supply unit 720. The supply power control unit 712 can apply the supply power to the PA 750 by controlling the power supply 720. [ The power that power supply 720 applies to PA 750 is termed PA supply power. The power supply control unit 712 may control the power supply 720 to adjust the voltage applied by the power supply 720 to the PA 750. [ The voltage that power supply 720 applies to PA 750 is termed PA supply voltage. As the power supply 720 regulates the PA supply voltage, the current supplied to the PA 750 can be regulated. The PA 750 may be a variable switching amplifier. PA 750 may be designed as an E-class switching amplifier. The output power of the PA 750 may be determined by the frequency of the signal applied from the oscillator 760 and the supply power applied from the power supply 720. [ And the power output from the PA 750 is referred to as PA power. In addition, the PA current is the current supplied to the PA 750 as the supply power control unit 712 controls the power supply 720. The PA voltage is the voltage of the PA power.

The source resonator 760 transmits the PA power to the target device 520 as electromagnetic energy.

The matching controller 755 may match the impedance between the PA 750 and the source resonator 760. The matching controller 755 may be a matching circuit. The matching controller 755 may change the matching impedance and the matching frequency. The control and communication unit 710 may control the matching control unit 755 to change the matching impedance and the matching frequency.

The power detector 730 can detect the current and voltage of the power supplied by the power supply 720 and transmit information on the detected current and voltage to the control and communication unit 710. The power detector 730 may detect the PA power (or PA current) and the PA voltage and may transmit information about the detected PA power (or PA current and PA output voltage) to the control and communication unit 710 have. The power detector 730 may be used to monitor the power supply to the target device 520 and detect the load modulation of the target device 520 by detecting a change in load and mode of the target device 520. [ .

8 is a structural diagram of a target device according to an embodiment.

The target device 520 includes a target resonator 810, a matching control unit 815, a rectification unit 820, a modulation / demodulation unit 830, a DC / DC converter 840, a power detector 860, a control and communication unit 870, A switch portion 880 and a load 890. [

The target resonator 810 may be the target resonator 121. The rectifying unit 820 may be a rectifying unit 122. The DC / DC converter 840 may be a DC / DC converter 123. The control and communication unit 870 may be a control and communication unit 126. The switch unit 880 may be the switch unit 124. [ The load 890 may be the charging unit 125.

The target resonator 810 may receive the electromagnetic energy output from the source resonator 760 of the source device 510. That is, the target resonator 810 receives power from the source device 510 through magnetic coupling with the source resonator 760. The received power may be used as " communication current " or " charging power ". In addition, the target resonator 810 may receive various messages from the source device 510 via in-band communication.

The matching control unit 815 can match the impedance between the target resonator 810 and the rectifying unit 820. The matching controller 815 may be a matching circuit. The matching controller 815 may change the matching impedance and the matching frequency. The control and communication unit 870 may control the matching control unit 815 to change the matching impedance and the matching frequency.

The rectification section 820 can generate a DC voltage by rectifying the alternating voltage output from the target resonator 810. [ That is, the rectifying unit 820 can rectify the AC voltage received through the target resonator 810. [

The DC / DC converter 840 can adjust the level of the DC voltage output from the rectifier 820 according to the capacity of the load 890. For example, the DC / DC converter 840 can adjust the level of the DC voltage output from the rectifying part to 3 to 10V.

The power detector 860 can detect the output power and the output voltage of the DC / DC converter 840. The power detector 860 can transmit the output power and the output voltage of the detected DC / DC converter 840 to the control and communication unit 870.

The switch unit 880 can be turned ON / OFF under the control of the control and communication unit 870. For example, when the target device 520 (or the load 890) is buffered, the switch portion 880 may be turned off. When the switch unit 880 is turned off, the control and communication unit 710 of the source device 510 can detect the power that the target device 520 receives. Hereinafter, the power received by the target device 520 is referred to as a received power. That is, when the switch portion 880 is turned off, the magnetic coupling between the source resonator 760 and the target resonator 810 can be eliminated.

The load 890 may include a battery. The load 890 may include a charging unit 125. The load 890 can be charged using the DC voltage output from the DC / DC converter 840.

The control and communication unit 870 can perform in-band communication with the source device 510 using the resonance frequency. The control and communication unit 870 can use the modulation / demodulation unit 830 for in-band communication. The control and communication unit 870 may include a modulation and demodulation unit 830 and the function of the modulation and demodulation unit 830 may be performed by the control and communication unit 870.

The demodulation unit 830 detects a signal between the target resonator 810 and the rectification unit 820 or an output signal of the rectification unit 820 and demodulates the signal received by the target device 520. [ That is, the modem unit 830 can demodulate the signal received by the target device 520 through the in-band communication. Also, the modulation / demodulation unit 830 can modulate the signal transmitted to the source device 510 by adjusting the impedance of the target resonator 810. The modulation / demodulation unit 830 can modulate a signal transmitted to the source device 510 through ON / OFF of the switch unit 880.

9 is a flowchart of a power control method of a wireless power transmission and charging system according to an embodiment.

In step 910, an initial power control is performed. The initial power control may be to control and transmit the wireless transmit power when the source device 510 and the target device 520 initiate the connection. The power required for the target device 520 can be appropriately transmitted in consideration of the efficiency difference between the source resonator 760 and the target resonator 810. [ The required power of the target device 520 may mean the power required to charge the load 890 of the target device 520.

In step 920, power control corresponding to a change in target load is performed.

The target load may refer to the load as viewed from the output end of the PA 750. That is, the target load may mean a load applied to the output terminal of the PA 750. [

The change in the target load means that 1) the number of target devices 520 being charged through the source device 510 is changed or 2) the battery charging mode of the target device 520 is changed (for example, A constant current (CC) mode to a constant voltage (CV) mode) or the like.

&Quot; Power control for change of target load " may mean controlling and transmitting power in accordance with a varying load.

FIG. 10 illustrates conditions of power control according to an example.

FIG. 10 may be a simplified representation of the source device 510 and the target device 520 of FIG.

The source 1010 may represent a portion of the source device 510 other than the matching control 755 and the source resonator 760. The matching network 1020 may represent a matching controller 755. The resonator 1030 may represent a source resonator 760.

The resonator 1040 may represent a target resonator 1040. The matching network 1050 may represent the matching controller 815. The load 1060 may represent a load 890.

The source device 510 may control the PA power (or source power) to provide the required power to the target load (i.e., the target device 520 or the load 890 in the target device 5120). The source device 510 can control the PA power by controlling the PA power supply.

To control the PA power, the source device 510 must detect the wireless power transfer efficiency between the source resonator 760 and the target resonator 810 and transmit the adjusted output power in consideration of the detected efficiency.

When the efficiency between the source resonator 760 and the target resonator 810 is low, the source device 510 must transmit higher power to the target device 520 in view of the above low efficiency. When the PA power is high, heat can be generated in the target device 520 by 1) the source device 510, 2) between the source resonator 760 and the target resonator 810, or 3) , The source device 510 and the target device 520) may be degraded. Thus, if low efficiency is detected between the source resonator 760 and the target resonator 810, the source device 510 may not transmit PA power to the target device 520. [

In the following, conditions for the source device 510 to control power will be described. In order to provide the required power to the target device 520, the PA 760 should output a power corresponding to the target load. In order for the PA 760 to output power to meet the target load, the following two conditions must be satisfied.

1) Impedance Matching Condition: The source-side impedance shall meet the matching condition for the load impedance. Here, the source-side impedance means 1) the impedance of the source device 510 including the source resonator 760 and 2) the target resonator 810.

Whether or not the above matching is satisfied can be confirmed through a reflection coefficient value. The reflection coefficient can be calculated according to the following equation (5).

는 반사 계수이다. V_i는 입사 파(incident wave)이다. V_r은 반사 파(reflected wave)이다. Z_o는 소스 임피던스이다. Z_L은 부하 임피던스 이다.here,

Is the reflection coefficient. V _i is an incident wave. V _r is the reflected wave. Z _o is the source impedance. Z _L is the load impedance.

2) Resonant frequency conditions between the source device 510 and the target device 520: The resonant frequencies of the source resonator 760 and the target resonator 810 should be the same.

Figure 11 illustrates the maximum efficiency point according to one embodiment.

Graph 1100 represents the maximum efficiency point 1130. [ The x axis of graph 1100 represents the frequency. The y-axis of the graph 1100 represents the value of the S parameter.

The source resonator 760 and the target resonator 810 may be manufactured differently for each company. This manufacturing difference may cause a difference in the efficiency of the source resonator 760 and the target resonator 810.

The wireless charge coupling efficiency means the wireless power transmission efficiency from the source resonator 760 to the target resonator 810. In order for the source device 510 to send the required power to the target device 520, the source device 510 needs to know the wireless fill coupling efficiency. The source device 510 may transmit the adjusted power in consideration of the wireless charging coupling efficiency.

The coupling efficiency of wireless charging can be measured using a Vector Network Analyzer (VNA). In order to measure the S-parameter, the input RF stage (i.e., the output stage of the PA 750 or the input stage of the source resonator 760) is connected to the first terminal of the VNA and the receiving RF stage 810) or the input terminal of the rectifying unit 820) is connected to the second terminal of the VNA.

When P _input is the output power of the VNA, the input power input to the input RF stage can be expressed by Equation (6) below. The output power output to the receiving RF stage can be expressed by Equation (7) below. The loss can be expressed by the following equation (8).

Here, S11 means input to the first terminal of the VNA. S21 means input to the second terminal of the VNA.

Therefore, the coupling efficiency can be defined by the S-parameter as shown in Equation (9) and Equation (10) below.

The maximum possible coupling efficiency means the coupling efficiency considering the power reflected by the resonators 760 and 810.

12 is a flow diagram of a method for detecting efficiency of a wireless power transmission in accordance with one embodiment.

12 may be an example of how the source device 510 detects the efficiency of the wireless power transmission to the target device 520 and transmits the output power to the target device 520 in accordance with the detected efficiency.

In step 1210, the control and communication unit 710 receives information about the required power required by the target device 520 from the target device 520. [ The required power may be the power required to charge the load 890 of the target device 520. The information on the required power includes information on 1) the load 910 (or the battery), 2) the voltage and current of the load 910 (or the battery), 3) 4) the power receiving capacity of the target device 520, and 5) the voltage and current of the target device 520, and so on.

In step 1220, the control and communication unit 710 determines an initial value of the PA power based on information about the power required by the target device 520. [ The PA power having the above initial value is named PA initial power.

The source device 510 may know the power delivered to the target device 520 by monitoring the PA power.

In step 1230, the control and communication unit 710 (or the power supply control unit 712) controls the power supply 720 to adjust the PA power according to the determined initial value. The PA 750 transmits the PA power according to the initial value to the target device 520 through the source resonator 760. [

In step 1240, the power detector 730 detects the PA current (or PA power) output from the PA 750.

In step 1250, the control and communication unit 710 controls the PA power based on the detected PA current. The control and communication unit 710 can increase the PA power when the detected PA current increases.

In step 1260, the control and communication unit 710 determines whether the detected PA current changes. If the PA current does not change, then step 1270 is performed. If the PA current changes, step 1250 is repeated.

That is, in steps 1250 and 1260, the control and communication unit 710 increases the PA power until the PA current is constant when the detected PA current increases. That is, in steps 1250 and 1260, the control and communication unit 710 may adjust the PA power based on the detected PA current. At this time, the control and communication unit 710 may control the PA supply voltage based on the efficiency between the source resonator 790 and the target resonator 810 until the PA current is constant. That is, the PA supply voltage can be controlled based on the efficiency between the resonators 790 and 810.

In step 1270, the control and communication unit 710 receives information about the received power that the target device 520 receives from the target device 520. [

In step 1280, the control and communication unit 710 calculates the efficiency of the wireless power transmission based on the adjusted PA power and received power. For example, if the determined PA power is 6W, the efficiency may be 0.5 or 50%, as compared to a received power of 3W.

In step 1290, the control and communication unit 710 (or the supply power control unit 712) controls the power supply 720 to adjust the PA power according to the calculated efficiency. That is, in step 1290, the control and communication unit 710 (or the supply power control unit 712) controls the PA supply voltage according to the calculated efficiency. The PA 750 transmits the PA power according to the calculated efficiency to the target device 520 via the source resonator 760. Depending on the load 890 of the target device 520, When the voltage is low (or the current is high) even at the same supply power, high heat is generated and the loss increases. For example, even if the output power is 10W, more heat is generated at a voltage of 1V and a current of 10A than at a voltage of 10V and a current of 1A, and the loss increases. Accordingly, the control and communication unit 710 (or the supply power control unit 712) controls the PA power (or PA voltage) based on the PA current value based on the efficiency.

In steps 1240 to 1290, the control and communication unit 710 determines the reception power received by the target device 520 through communication with the target device 520 when the change in the current of the PA power enters a certain region Can be confirmed. The control and communication unit 710 can confirm the efficiency between the resonators 760 and 810 using the PA power and the received power. Control and communication portion 710 may ultimately adjust and transmit power for charging target device 520 (or load 890), in accordance with the identified efficiency.

In addition, when the source device 510 transmits power for charging the target device 520 (or the load 890), the control and communication portion 710 may communicate with the target device 520 ( (That is, a change in the load 890) of the load 890 (or the load 890). Thus, step 1270 may be omitted. If step 1270 is omitted, then in step 1080, the control and communication unit 710 may calculate the efficiency of the wireless power transmission based on the adjusted PA power and information on the required power.

In the following, methods of detecting the efficiency of the wireless power and controlling the power according to the detected efficiency are described.

13 illustrates a method for detecting the change in efficiency between resonators according to an example.

The x-axis of graph 1300 represents the time, and the y-axis represents the current.

If the power required by the load 890 is not supplied when the load 890 (e.g., battery) of the target device 520 is charged, then at the output end of the PA 750, High load is seen. When the current detected by the PA 750 is low, the control and communication unit 710 may determine that the power required for charging the target device 520 is insufficient, (720). As shown, the PA currents 1310, 1320, and 1330 gradually increase as the control and communication unit 710 determines that current is low, and then stop to change while reaching a constant level.

 In this manner, the control and communication portion 710 may repeat the detection of the PA current (Step 1240) and the communication with the target device 520 (Step 1270) until appropriate power is delivered to the target device 520. [

To provide the necessary power to the load 890, the PA power can be controlled based on the PA current. The control and communication unit 710 can determine the condition of the control based on the increase and decrease of the PA current. When power is supplied to the PA 750 while controlling the PA power, when the load 890 is smaller than the supplied power, the PA current increases. This increase may mean that the power supplied to the load 890 is insufficient. The control and communication unit 710 may control the PA power based on the result of detection of the PA current. If the PA current does not increase any more, the control and communication unit 710 may determine that the required power is supplied to the load 890 and may not increase the PA power any more.

14 shows the adjustment of the PA power according to an example.

The change in PA power (or the level of the controlled PA supply voltage) 1410 and the detected PA current 1420 are shown. The dotted line 1430 represents the required power of the target device 520. Dotted line 1440 represents the maximum level of PA power. Box 1450 indicates that communication between the source device 510 and the target device 520 is performed.

In steps 1210 and 1220, the PA initial power is determined. In this example, the required power of the target device 520 is 3W. Assuming that the efficiency between the source resonator 760 and the target resonator 810 is 100%, in step 1220, the control and communication unit 710 determines the PA initial power to be 3W.

The assumed efficiency used in step 1220 is named home efficiency. The home efficiency may be determined based on 1) the application of the target device 520, 2) the function of the target device 520, 3) the operating environment of the wireless power transmission and charging system 500, and so on. In general, the home efficiency can have a value of 50 to 100%.

The PA current detected in step 1240 increases gradually. In step 1250, the control and communication unit 710 controls the PA power so that power can be delivered to the load 890 of the target device 520. [

The control and communication unit 710 can know the power supplied to the load 890 by detecting the PA supply power (or the PA supply voltage and the PA supply current) through the power detector 730. [

15 shows the fixing of the PA current according to an example.

The change in PA power 1510 and the detected PA current 1520 are shown. The dotted line 1530 represents the required power of the target device 520. Dotted line 1540 represents the maximum level of the output power of PA 750.

In the PA 750, only the power of the load 890 of the target device 520 is output. That is, without a change in the load 890, the PA current hardly changes even if the PA supply voltage increases.

By controlling the PA supply voltage, the PA current 1520 is constant from a particular point even if the PA power 1510 rises.

The control and communication portion 710 may be able to determine whether the PA device is receiving a charge or not through PA current detection (step 1240) and communication with the target device 520 (step 1270). If it is confirmed that the required power (required voltage and necessary current) is supplied, the control and communication unit 710 can switch to the charging mode and transmit power to the target device 520. [

In this example, the PA power transmitted by the source device 510 to the target device 520 is 6W, and the power delivered to the load 890 is 3W, so that the wireless power transmission efficiency is 50%.

FIG. 16 illustrates a case where power transmission is interrupted by a low radio power transmission efficiency according to an example.

The change in PA power 1610 and the detected PA current 1620 are shown. The dotted line 1630 represents the required power of the target device 520. Dotted line 1640 represents the maximum level of PA power.

If the efficiency between the source resonator 760 and the target resonator 810 is low and the power is difficult to transmit, the PA power transmitted by the source device 510 to the target device 520 is 7W and the power delivered to the load 890 Becomes 3A. The wireless power transmission efficiency is 42.8%.

17 is a flow diagram of a method for detecting the efficiency of a wireless power transmission using a virtual load according to an embodiment.

17 may be an example of how the source device 510 detects the efficiency of the wireless power transmission to the target device 520 and transmits the output power to the target device 520 in accordance with the detected efficiency.

In order to detect the efficiency between the resonators 760 and 810, the control and communication unit 710 may use the information transmitted from the target device 520. The above information is information generated based on the power flowing in the target device 520 (or the power received by the target device 520). In the present embodiment, the above information is power flowing to the virtual load of the target device 520. [ The power flowing in the virtual load is called the virtual load power.

The virtual load may be a load having the same value as 1) the actual load 890 of the target device 520 or 2) a load having a resistance value that is a reference between the source device 510 and the target device 520 have. The reference resistance is referred to as a reference load.

Step 1710 corresponds to step 1210 described above. Step 1720 corresponds to step 1220 described above. Step 1730 corresponds to step 1230 or steps 1230-1260. Duplicate description is omitted.

In step 1740, the target device 520 receives and detects the virtual load power. The target device 520 transmits information about the detected virtual load power to the source device 510. The source device 510 receives information about the virtual load power.

In step 1750, the control and communication unit 710 compares the PA power and the virtual load power to calculate the wireless power transmission efficiency.

In step 1760, the control and communication unit 710 calculates the power to be output (i.e., the PA power) according to the calculated radio power transmission efficiency.

In step 1770, the control and communication unit 710 (or the power supply control unit 712) controls the power supply 720 such that the calculated PA power is output. The PA power is adjusted by the above control. The PA 750 transmits the adjusted PA power to the target device 520 via the source resonator 760.

Figure 18 illustrates the connection of a virtual load according to an example.

In Fig. 18, the remaining components 1810 of the components of the target device 520 are shown, except for the load. The virtual load 1820 is connected in parallel with the load 890.

The target device 520 (or the control and communication portion 870) may use path control to select one of the path 1830 to the load 890 and the path 1840 to the virtual load 1820. The power detector 860 can detect the power flowing to the virtual load 1820 and transmit it to the control and communication unit 870. The control and communication unit 870 870 transmits the detected power through the communication to the source device 510. [

FIG. 19 illustrates path selection using an SPDT switch according to an example.

A single pole double throw (SPDT) switch 1910 delivers the transmit power transmitted from the power detector 860 to one of the load 890 and the virtual load 1820. The switch portion 880 may include an SPDT switch 1910.

The SPDT switch 1910 selects one target to transmit the transmission power among the load 890 and the virtual load 1820 under the control of the control and communication unit 870. When the SPDT switch 1910 is connected to the virtual load 1820, the power detector 860 can detect the power flowing to the virtual load 1820 and transmit it to the control and communication unit 870.

20 is a flow diagram of a method for detecting efficiency of a wireless power transmission using load modulation in accordance with one embodiment.

20 may be an example of how the source device 510 detects the efficiency of the wireless power transmission to the target device 520 and transmits the output power to the target device 520 in accordance with the detected efficiency.

In order to detect the efficiency between the resonators 760 and 810, the control and communication unit 710 may use the information transmitted from the target device 520. The above information is information generated based on the power flowing in the target device 520. In the present embodiment, the above information is the current flowing to the load modulator 2100 of the target device 520, which will be described later. The power flowing in the load modulator 2100 is referred to as a load modulator power. The current flowing in the load modulator 2100 is referred to as a load modulator current.

Step 2010 corresponds to step 1210 described above. Step 2020 corresponds to step 1220 described above. Step 2030 corresponds to step 1230 or steps 1230-1260. Duplicate description is omitted.

In step 2040, the target device 520 receives and detects the load modulator current. The target device 520 transmits information about the detected load modulator current to the source device 510. The source device 510 receives information about the load modulator current.

In step 2050, the control and communication unit 710 calculates the wireless power transmission efficiency based on the PA power and the load modulator current. That is, the control and communication unit 710 compares the PA power and the received power of the target device 520 based on the load modulator current to calculate the wireless power transmission efficiency.

Steps 2060 and 2070 correspond to steps 1760 and 1770, respectively. Also, the example described with reference to Fig. 17 can be applied to the example of Fig.

FIG. 21 illustrates a load modulator power detection method according to an example.

The load modulator 2100 receives the power received by the target device 510 from the rectifier 820. When the path to the load 890 is turned OFF, the load modulator 2100 is turned ON and received power is input to the load modulator 2100. That is, the power of the load modulator is the power output from the rectifying unit 820 in a state in which the path to the load 890 is OFF. The load modulator current is the current flowing in the target device 520 with the path to the load 890 blocked.

The load modulator 2100 may include a resistor 2110, a transistor 2120, and a differential amplifier 2130. The resistor 2110 is a load of the load modulator 2100.

The load modulator power can be detected by using the current flowing in the resistor 2110. The control and communication unit 870 can turn on the load modulator 2100 by controlling the transistor 2120. [ With the load modulator 2100 turned on, the load modulator current I _s flows through the resistor 2110 to the transistor 2120. The differential amplifier 2130 detects the voltage across the resistor 2110 and transmits it to the control and communication unit 870. The control and communication unit 870 can calculate the current I _s flowing in the resistor 2110 (or the transistor 2120) because it knows the resistance value of the resistor 2110 and the voltage across the resistor 2110 . The control and communication unit 870 transmits the calculated load modulator current I _s to the source device 510.

22 is a flow diagram of a method for detecting efficiency of a wireless power transmission based on received power of a target device according to an embodiment.

22 may be an example of how the source device 510 detects the efficiency of the wireless power transmission to the target device 520 and transmits the output power to the target device 520 in accordance with the detected efficiency.

In order to detect the efficiency between the resonators 760 and 810, the control and communication unit 710 may use the information transmitted from the target device 520. The above information is information generated based on the power flowing in the target device 520. In this embodiment, the information may be 1) power flowing in the target device 520, 2) virtual load power, or 3) load modulator current.

Step 2210 corresponds to step 1210 described above. Step 2220 corresponds to step 1220 described above. Step 2230 corresponds to step 1230. Duplicate description is omitted.

In step 2240, the control and communication unit 710 requests the target device 520 for information about the received power. The target device 520 transmits information about the received power of the target device 510 to the source device 510. [ The control and communication unit 710 receives information on the received power from the target device 520. [

In step 2250, the control and communication unit 710 compares the received power and the required power. If the received power has reached the required power, step 2270 is performed. If the received power is insufficient relative to the required power, step 2260 is repeatedly performed.

In step 2260, the control and communication unit 710 controls the PA power based on the result of the comparison between the received power and the required power. The control and communication unit 710 can increase the PA power when the received power does not reach the required power.

By steps 2250 and 2260, the control and communication unit 710 can adjust the PA power to further transmit insufficient power when the received power is insufficient relative to the required power.

By repeating step 2240, the control and communication unit 710 can know the increased received power.

In step 2250, the control and communication unit 710 compares the PA power and the received power to calculate the wireless power transmission efficiency.

Step 2260 corresponds to step 1760. Step 2270 corresponds to step 1770. Duplicate description is omitted.

FIG. 23 illustrates power control based on received power according to an example.

PA power 2310 and required power 3W are shown. 3 W of power must be transmitted to the target device 520. Boxes 2330 and 2340 represent communication between the source device 510 and the target device 520.

The initial value of the PA power 2310 is 3W. Through steps 2230 through 2250, the control and communication unit 710 adjusts the PA power 2310 to 4W and raises the PA power 2310 again to 6W. When the PA power 2310 becomes 6W, the received power reaches the required power (3W).

24 illustrates over power control according to an example.

The source device 510 and the target device 520 may be manufactured by various vendors. The efficiency between the source resonator 790 and the target resonator 810 may also be different depending on the manufacturer because each vendor manufactures the source device 510 and the target device 520 using different methods. An indicator of the wireless power transmission efficiency is the wireless power transmission efficiency between the resonators 790 and 810. The source device 510 transmits high PA power in a state where the wireless power transmission efficiency is low. As the source device 510 transmits high PA power, a problem may arise in the reliability of the source device 510. In addition, heat generated in the source device 510 may cause product breakage and energy waste.

Thus, in embodiments of the present invention described above, if the detected wireless power transmission efficiency is lower than the reference efficiency, the control and communication unit 710 may generate an alarm or block the PA power transmission, Can be stopped.

The above operation can also be applied when the PA current is equal to or greater than a predetermined value. That is, in the embodiments of the present invention described above, the impedance of the load 890 may vary due to variations in the PA supply voltage or an external change. Because the impedance of the load 890 is changing, the PA supply current may increase above a set value. When the PA current is greater than a predetermined value, the control and communication unit 710 may generate an alarm or interrupt the PA power transmission, and may stop the operation of the source device 510. The set value may be determined based on the wireless power transmission efficiency and the PA power.

PA power 2410 and required power 2420 are shown. 10 W of power must be transmitted to the target device 520. Boxes 2430 and 2440 represent communication between the source device 510 and the target device 520.

In this example, the reference efficiency is 60% and the efficiency between the resonators 790 and 810 is 50%. According to the method described above with reference to Fig. 22, the PA power increases from 10W to 20W. However, as the PA power increases, the wireless power transmission efficiency becomes lower than the reference efficiency. The control and communication unit 710 detects that the wireless power transmission efficiency is lower than the reference efficiency and turns off the operation of the source device 510 and generates an alarm at the source device 510 to charge the target device 520 Can not be done.

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

25, an electric vehicle charging system 2500 includes a source system 2510, a source resonator 2520, a target resonator 2530, a target system 2540, and a battery 2550 for an electric vehicle.

The electric vehicle charging system 2500 has a structure similar to that of the wireless power transmission system of Fig. That is, the electric vehicle charging system 2500 includes a source composed of a source system 2510 and a source resonator 2520. The electric vehicle charging system 2500 also includes a target comprised of a target resonator 2530 and a target system 2540.

In this case, the source system 2510 may include an AC / DC converter, a power detector, a power conversion unit, a control unit, and a communication unit like the source device 110 of FIG. At this time, the target system 2540 may include a rectifier, a DC / DC converter, a switch, a charger, and a control and communication unit, as in the target device 120 of FIG.

The battery 2540 for an electric vehicle may be charged by the target system 2540.

The electric vehicle charging system 2500 can use a resonant frequency of several KHz to several tens MHz.

The source system 2510 can generate power according to the type of the charged vehicle, the capacity of the battery, and the state of charge of the battery, and supply the generated power to the target system 2540.

The source system 2510 may perform control to align the source resonator 2520 and the target resonator 2530. For example, the control of the source system 2510 may control the alignment by sending a message to the target system 2540 if the alignment of the source resonator 2520 and the target resonator 2530 is not aligned.

In this case, the case where the alignment is not correct may be a case where the position of the target resonator 2530 is not in a position for maximizing magnetic resonance. That is, if the vehicle is not correctly stopped, the source system 2510 may induce the alignment of the source resonator 2520 and the target resonator 2530 to match, thereby inducing the position of the vehicle to be adjusted.

The source system 2510 and the target system 2540 can communicate with each other via communication, send and receive identifiers of vehicles, and exchange various messages.

The contents described in Figs. 2 to 24 can be applied to the electric vehicle charging system 2500. Fig. However, the electric vehicle charging system 2500 may use a resonance frequency of several KHz to several tens MHz and may perform power transmission of several tens of watt or more in order to charge the battery 2550 for an electric vehicle.

26 and 27 show applications in which a wireless power receiving apparatus and a wireless power transmission apparatus according to an embodiment can be installed.

26, (a) shows wireless power charging between pad 2610 and mobile terminal 2620, (b) shows wireless power charging between pads 2630 and 2640 and hearing aids 2650 and 2660, .

A wireless power transmission device according to one embodiment may be mounted on a pad 2610. [ The wireless power receiving apparatus according to one embodiment may be mounted on the mobile terminal 2620. At this time, the pad 2610 can charge one mobile terminal 2620.

Two wireless power transmission apparatuses according to an embodiment may be mounted on the first pad 2630 and the second pad 2640, respectively. The hearing aid 2650 represents the hearing aid of the left ear and the hearing aid 2660 represents the hearing aid of the right ear. Two wireless power receiving apparatuses according to an embodiment may be mounted on the hearing aid 2650 and the hearing aid 2660, respectively.

27A shows wireless power charging between the electronic device 2710 inserted into the human body and the mobile terminal 2720 and FIGURE 27B shows the wireless power charging between the hearing aid 2730 and the mobile terminal 2740 .

The wireless power transmission apparatus according to one embodiment and the wireless power receiving apparatus according to an embodiment may be mounted on the mobile terminal 2720. [ A wireless power receiving apparatus according to an embodiment may be mounted on an electronic device 2710 inserted into a human body. The electronic device 2710 inserted into the human body can be charged by receiving electric power from the mobile terminal 2720. [

The wireless power transmission apparatus according to an embodiment and the wireless power receiving apparatus according to an embodiment may be mounted on the mobile terminal 2740. The wireless power receiving apparatus according to one embodiment may be mounted on the hearing aid 2730. The hearing aid 2730 may be charged by receiving power from the mobile terminal 2740. In addition to the hearing aid 2730, low power electronics such as a Bluetooth earphone may also be powered by receiving power from the mobile terminal 2740.

28 shows a configuration example of a wireless power transmission apparatus wireless power receiving apparatus according to an embodiment.

In FIG. 28, the wireless power transmission device 2810 may be mounted on each of the first pad 2630 and the second pad 2640 in FIG. 28, the wireless power transmission device 2810 may be mounted on the mobile terminal 2740 of Fig.

28, the wireless power receiving apparatus 2820 can be mounted on the hearing aid 2650 and the hearing aid 2660, respectively.

The wireless power transmission device 2810 may include a configuration similar to the source device 110 of FIG. That is, wireless power transmission device 2810 may include a configuration for transmitting power using magnetic coupling.

In FIG. 28, the communication and tracking unit 2811 performs communication with the wireless power receiving apparatus 2820, and performs impedance control and resonance frequency control for maintaining the wireless power transmission efficiency. That is, the communication and tracking unit 2811 may perform similar functions as the power conversion unit 114 and the control and communication unit 115 of FIG.

The wireless power receiving device 2820 may include a configuration similar to the target device 120 of FIG. That is, the wireless power receiving apparatus 2820 includes a configuration for wirelessly receiving power to charge the battery. The wireless power receiving device 2820 may include a target resonator, a rectifier, a DC / DC converter, and a charging circuit. The wireless power receiving device 2820 may also include a communication and control unit 2823.

Communication and control unit 2823 may communicate with wireless power transmission device 2810 and perform operations for overvoltage and overcurrent protection.

Wireless power receiving device 2820 may include an auditory device circuit 2821. The auditory device circuit 2821 may be charged by a battery. The auditory device circuit 2821 may include a microphone, an analog-to-digital converter, a processor, a digital-to-analog converter, and a receiver. That is, the hearing instrument circuit 2821 may include the same configuration as the hearing aid.

The method according to an embodiment of the present invention can be implemented in the form of a program command which 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, and the like, alone or in combination. The program instructions recorded on the medium may be those specially designed and constructed for the present invention or may be available to those skilled in the art of computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media such as floppy disks; Magneto-optical media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions include machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. This is possible.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the equivalents of the claims, as well as the claims.

510: source device
520: Target device

Claims (22)

A method of detecting a wireless power transmission efficiency of a source device to a target device,
Receiving first information on the required power of the target device from the target device;
Determining a first power of the power amplifier of the source device based on the first information;
Transmitting wireless power corresponding to the first power to the target device;
Determining a second power of the power amplifier if the current of the power amplifier is maintained at a constant level, the current of the power amplifier being changed by the target device until the wireless power corresponding to the first information is received box-; And
Calculating a wireless power transmission efficiency based on the second power and the first information
/ RTI > for a wireless power transmission efficiency detection method. delete The method according to claim 1,
Receiving second information on the power received by the target device from the target device
Further comprising:
Wherein the wireless power transmission efficiency is calculated based on the second information and the second power. The method according to claim 1,
Wherein the determining the second power comprises:
And increasing the power level of the power amplifier until the current of the power amplifier becomes constant when the current of the power amplifier increases. The method according to claim 1,
Stopping the operation of the source device when the calculated radio power transmission efficiency is lower than the reference efficiency
Further comprising the step of: Receiving first information on a power required by the target device from a target device;
Determining an output power of a power amplifier of the source device based on the first information;
Transmitting wireless power according to the output power to the target device;
Receiving second information from the target device about the power received by the target device;
Calculating wireless power transmission efficiency based on the second information and the output power
Lt; / RTI >
Wherein the second information is information on a current flowing in the load modulator in a state in which the path to the load of the target device is blocked and the received power is input to the load modulator of the target device,
Wireless power transmission efficiency detection method. delete delete delete The method according to claim 6,
Stopping the operation of the source device when the calculated radio power transmission efficiency is lower than the reference efficiency
Further comprising the step of: A computer-readable recording medium embodying a program for performing the method of detecting a wireless power transmission efficiency according to any one of claims 1, 3, 4, 5, and 6. A control unit for determining a first power of the power amplifier of the wireless power transmission apparatus based on first information on a required power of the target device; And
And a resonator for transmitting radio power according to the first power to the target device
Lt; / RTI >
Wherein the control unit determines a second power of the power amplifier when the current of the power amplifier is maintained at a predetermined level, and the current of the power amplifier is determined by the target device when the wireless power corresponding to the first information is received , And calculates a wireless power transmission efficiency based on the second power and the first information. 13. The method of claim 12,
And the control unit receives the first information from the target device. 13. The method of claim 12,
Wherein the control unit receives second information on the power received by the target device from the target device and calculates the wireless power transmission efficiency based on the second information and the second power. 13. The method of claim 12,
Wherein the controller increases the power level of the power amplifier until the current of the power amplifier becomes constant when the current of the power amplifier increases. 13. The method of claim 12,
Wherein the controller stops operation of the wireless power transmission apparatus when the calculated wireless power transmission efficiency is lower than a reference efficiency. A controller for determining the output power of the amplifier of the wireless power transmission apparatus based on the first information on the power required by the target device; And
And a resonator for transmitting radio power according to the output power to the target device
Lt; / RTI >
Wherein the control unit receives second information on the power received by the target device from the target device, calculates a wireless power transmission efficiency based on the second information and the output power,
Wherein the second information is information on a current flowing in the load modulator in a state in which the path to the load of the target device is blocked and the received power is input to the load modulator of the target device,
Wireless power transmission device. delete delete delete 18. The method of claim 17,
Wherein the controller stops operation of the wireless power transmission apparatus when the calculated wireless power transmission efficiency is lower than a reference efficiency. 18. The method of claim 17,
The control unit suspends operation of the wireless power transmission apparatus when the current of the output power is equal to or greater than a predetermined value, and the set value is determined based on the wireless power transmission efficiency and the output power.

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