KR20110134969A - Adaptive transmit power control apparatus and method for electromagnetic interference suppression in wireless power transmission systems - Google Patents

Abstract

PURPOSE: An adaptive transmission power control apparatus for reducing electromagnetic interference in a wireless power transmission system and a method thereof are provided to reduce and eliminate electromagnetic interference phenomena affecting near electronic devices, thereby preventing unnecessary malfunction affecting the near electronic devices. CONSTITUTION: A receiving part(310) receives information related to electromagnetic interference affecting near electronic devices. A power transmission control part(320) performs a power transmission control process which considers the electromagnetic interference. The power transmission control part includes a transmission power reduction part which reduces a power amount which is being wirelessly transmitted. A wireless transmission part(330) wirelessly transmits power according to the power transmission control process and information with respect to the power transmission control process. The information with respect to the power transmission control process includes a matching parameter comprising the wireless transmission part.

Description

Adaptive Transmit Power Control Apparatus and Method for Reduction of Electromagnetic Interference in Wireless Power Transmission System TECHNICAL FIELD

TECHNICAL FIELD The present invention relates to an apparatus and method for solving the problem of generating electromagnetic interference to a peripheral device that does not want to receive power when transmitting wireless power.

The research on wireless power transmission has begun to overcome the inconvenience of wired power supply due to the explosive increase of various electric devices including mobile devices and the limitation of existing battery capacity. However, in a wireless power transmission system, electromagnetic related signals from power transmitters may cause electromagnetic interference effects on peripheral devices that do not want to receive power.

That is, electromagnetic fields related to electromagnetic fields, such as magnetic fields emitted from power transmitters, may affect not only power receivers intended to receive power but also peripheral devices that do not want to receive power. The interference caused by the electromagnetic energy on the peripheral device is called electromagnetic interference (EMI). Electromagnetic interference can interfere with the normal operation of peripherals or cause unwanted power reception, noise and various disturbances. Specifically, a change in the magnetic field emitted from the power transmitter may cause abnormal operation by generating a current due to electromagnetic induction to the conductor of a stationary peripheral device. In addition, the static magnetic field generated by the power transmitter may cause a failure by generating current in the portable device even when the portable device moves around the magnetic field. In addition, when the power transmitter and peripheral devices that do not want to receive power have similar resonance conditions, magnetic resonance coupling may occur, which may cause malfunction of the peripheral devices.

In one aspect, an adaptive transmission power control apparatus for reducing electromagnetic interference in a wireless power transmission system includes a receiver for receiving information related to electromagnetic interference from a peripheral device to the peripheral device, the electromagnetic interference based on the information related to the electromagnetic interference A power transmission control unit for performing a power transmission control in consideration of the above, and a wireless transmission unit for wirelessly transmitting information on the power transmission control and the power according to the control.

The information on the power transmission control may include a matching parameter constituting the wireless transmission unit, and the power transmission control unit may include a matching parameter change unit which changes the matching parameter to a value different from a current value.

The power transmission control unit may include a resonance frequency changing unit for changing a resonance frequency used for wireless power transmission to another resonance frequency.

The power transmission control unit may include a frequency hopping scheme changing unit that changes the resonance frequency in a frequency hopping scheme that periodically changes a frequency with respect to a resonance pattern used for wireless power transmission.

The power transmission control unit may include a transmission power reduction unit for reducing the amount of power being wirelessly transmitted.

The power transmission control unit may include a transmission power direction changing unit for changing the direction of the transmission power so as not to transmit power in the direction of the peripheral device affected by the electromagnetic interference based on the received information related to the electromagnetic interference.

The wireless transmitter may move by using a moving object and transmit power.

The peripheral device may include a measuring unit periodically measuring electromagnetic interference on the peripheral device, a determining unit determining whether or not the electromagnetic interference has increased above a predetermined threshold value with respect to the measured electromagnetic interference, and the preset threshold value. If the measured electromagnetic interference is increased, it may include an information transmitter for transmitting information related to the electromagnetic interference.

In one aspect, an adaptive receiving power control apparatus for reducing electromagnetic interference in a wireless power transmission system, the receiving unit for receiving information on the power transmission control applied to the wireless power transmission device, transmitted from a wireless power transmission device, the receiving And a matching unit controlling the power receiving apparatus to be matched to the scheme applied to the wireless power transmitter based on the received information, and a power receiving unit receiving power from the wireless power transmitter based on the matched scheme.

The matching unit may control the power receiver in an impedance matching manner in response to a matching parameter changed in the wireless power transmitter.

The matching unit may change the frequency of the power receiver to match the resonance frequency in response to the resonance frequency changed in the wireless power transmitter.

The matching unit may change the frequency of the power receiver in the same manner as the hopping scheme in response to a frequency hopping scheme that periodically changes the frequency according to a predetermined pattern applied by the wireless power transmitter.

According to an aspect, an adaptive transmission power adjusting method for reducing electromagnetic interference in a wireless power transmission system includes receiving information related to electromagnetic interference from a peripheral device to the peripheral device, considering the electromagnetic interference based on the received information. Performing power transmission control and wirelessly transmitting information on the power transmission control and power according to the control.

The performing of the power transmission control may include performing power transmission control through at least one of changing a matching parameter, changing a resonance frequency, changing a resonance frequency by a frequency hopping method, decreasing a transmission power, and changing a transmission power direction. Can be done.

The performing of the power transmission control may include performing first power transmission control based on the received information related to the electromagnetic interference and performing information related to the electromagnetic interference updated from the peripheral device as a result of performing the first power transmission control. Performing the second power transfer control based on the control method.

The performing of the first power transfer control may include changing a matching parameter constituting the wireless power transfer system to a value different from a value currently being used, and the performing of the second power transfer control may include updated electromagnetic interference. Based on the related information, the resonant frequency used for wireless power transmission can be changed to another resonant frequency.

The performing of the first power transmission control may include changing a direction of transmission power such that power is not transmitted in the direction of the peripheral device affected by the electromagnetic interference based on the received information related to the electromagnetic interference, and transmitting the second power transmission. The performing of the control may change the resonant frequency in a frequency hopping manner in which the frequency is periodically changed according to a predetermined pattern with respect to the resonant frequency used for wireless power transmission based on the information related to the updated electromagnetic interference. .

The peripheral device periodically measures electromagnetic interference on the peripheral device, determining whether the electromagnetic interference has increased above the predetermined threshold value for the peripheral device with respect to the measured electromagnetic interference, and the threshold value is greater than the preset threshold value. If the measured electromagnetic interference is increased, the method may include transmitting information related to the electromagnetic interference.

In an aspect, an adaptive receiving power adjusting method for reducing electromagnetic interference in a wireless power transmission system may include receiving information about a power transmission control applied to the wireless power transmission device transmitted from a wireless power transmission device. Controlling the power receiver to match the scheme applied to the wireless power transmitter based on the information, and receiving power from the wireless power transmitter based on the matched scheme.

In a wireless power transmission system, the wireless power transmitter reduces and eliminates electromagnetic interference that may affect surrounding electrical devices, thereby preventing unnecessary malfunctions, unwanted power reception, noise, and disturbances on the peripheral devices.

1 is a view showing a wireless power transmission system according to one side.
2 is a diagram showing electromagnetic interference in a wireless power transmission system according to one side.
3 is a block diagram of an adaptive transmission power control apparatus for reducing electromagnetic interference in a wireless power transmission system according to one side.
4 is a block diagram of a power transmission control unit according to one side.
5 is a block diagram of an adaptive receiving power control apparatus for reducing electromagnetic interference in a wireless power transmission system according to one side.
6 is a diagram illustrating a meta-structured resonator according to one side.
FIG. 7 is a diagram illustrating an equivalent circuit of the resonator illustrated in FIG. 6.
8 is a diagram illustrating a meta-structured resonator according to another side.
9 is a view showing in detail the insertion position of the capacitor of FIG.
10 is a flowchart illustrating an adaptive transmission power adjusting method for reducing electromagnetic interference in a wireless power transmission system according to one side.
11 is a flowchart illustrating an adaptive transmission and reception power adjusting method for reducing electromagnetic interference in a wireless power transmission system according to one side.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, the wireless power transmission technology used in the wireless power transmission system will be described. Wireless power transmission technology can be classified into three types of electromagnetic induction method, radio wave reception method, electric field or magnetic field resonance method.

First, the electromagnetic induction method uses a phenomenon in which magnetic flux is generated when an alternating current flows in one coil after approaching two different coils close to each other, and thus electromotive force is generated in the other coil. The electromagnetic induction method has the most high efficiency and practical use, such as the power utilization efficiency is approximately 60-98%.

Second, in the radio wave reception method, radio wave energy is received and used by an antenna to convert an AC radio wave waveform into a direct current through a rectifier circuit to obtain power. Radio reception method is capable of transmitting wireless power over the longest distance (above several meters).

Third, the resonance method uses resonance of an electric field or a magnetic field, and transmits energy by resonating at the same frequency between devices. In case of using the resonance of the magnetic field, electric power is generated by using magnetic resonance coupling using the LC resonator structure. The magnetic resonance method is a technology that uses a near field effect of a short distance compared to the wavelength of the used frequency. Unlike the radio wave reception method, it is a non-radiative energy transmission, and matches the resonance frequency between the transmitter and the receiver. Send it. The magnetic resonance method increases the power transmission efficiency by about 50 ~ 60%, which is much higher than the radio wave reception type through radio wave radiation. Although the transmission / reception period distance is about several meters, although the technique used in the near field rather than the radio wave reception method, the power transmission is possible at a far distance than the electromagnetic induction type within a few mm.

1 is a diagram illustrating a wireless power transmission system according to one side.

In the example of FIG. 1, it is assumed that the wireless power transmitted through the wireless power transmission system is resonance power.

Referring to FIG. 1, a wireless power transmission system is a source-target structure consisting of a source and a target. That is, the wireless power transmission system includes a resonance power transmitter 110 corresponding to a source and a resonance power receiver 120 corresponding to a target.

The resonance power transmitter 110 includes a source unit 111 and a source resonator 115 that generate energy by receiving energy from an external voltage supply device. In this case, the external voltage source may be AC, DC, a battery, or the like. In addition, the resonance power transmission apparatus 110 may further include a matching control 113 that performs resonance frequency or impedance matching. In addition, the resonance power transmitter 110 may transmit data to the resonance power receiver 120 using the resonance frequency band.

The source unit 111 receives energy from an external voltage supply to generate resonance power. The source unit 111 rectifies an AC signal output from an AC-AC converter or an AC-AC converter for adjusting a signal level of an AC signal input from an external device to a desired level, thereby outputting a DC voltage having a predetermined level. It can include a DC-AC Inverter that generates an AC signal of several MHz to several tens of MHz band by fast switching the DC voltage output from the DC converter and the AC-DC converter. In addition, the source unit 111 may transmit the idle power to the target unit 125 while moving through the moving object rather than at a fixed position. For example, the source unit 111 may be included in a moving robot device.

The matching control 113 sets the resonance bandwidth of the source resonator 115 or the impedance matching frequency of the source resonator 115. The matching control unit 113 includes at least one of a source resonance bandwidth setting unit (not shown) or a source matching frequency setting unit (not shown). The source resonant bandwidth setting unit sets a resonance bandwidth of the source resonator 115. The source matching frequency setting unit sets the impedance matching frequency of the source resonator 115. In this case, the Q-factor of the source resonator 115 may be determined according to the resonance bandwidth of the source resonator or the impedance matching frequency of the source resonator.

The source resonator 115 transfers electromagnetic energy to the target resonator. That is, the source resonator 115 transmits the resonance power to the target device 120 through the magnetic coupling 101 with the target resonator 121. At this time, the source resonator 115 resonates within the set resonance bandwidth.

The resonance power receiver 120 includes a target resonator 121, a matching control unit 123 for performing resonance frequency or impedance matching, and a target unit 125 for transferring the received resonance power to a load. In addition, the resonance power receiver 120 may receive data from the resonance power transmitter 110 using the resonance frequency band.

The target resonator 121 receives electromagnetic energy from the source resonator 115. At this time, the target resonator 121 resonates within the set resonance bandwidth.

The matching control unit 123 sets at least one of a resonance bandwidth of the target resonator 121 or an impedance matching frequency of the target resonator 121. The matching control unit 123 includes at least one of a target resonance bandwidth setting unit (not shown) or a target matching frequency setting unit (not shown). The target resonance bandwidth setting unit sets a resonance bandwidth of the target resonator 121. The target matching frequency setting unit sets the impedance matching frequency of the target resonator 121. In this case, the Q-factor of the target resonator 121 may be determined according to the resonance bandwidth of the target resonator 121 or the impedance matching frequency of the target resonator 121.

The target unit 125 transfers the received resonance power to the load. At this time, the target unit 125 rectifies an AC signal received from the source resonator 115 to the target resonator 121 to generate a DC signal, and an AC-DC converter to adjust the signal level of the DC signal to adjust the device voltage. It may include a DC-DC converter that supplies a device or a load. The load capable of receiving the resonance power includes various home appliances including a digital photo frame, a speaker, a vacuum cleaner, a dryer, a shaver, a laptop PC, a computer, a peripheral device thereof, a mobile phone, a digital camera, a camcorder, an MP3 player, a PDA, and various portable devices. The device, in addition to the femtocell base station, various sensors and lighting equipment may be included.

The source resonator 115 and the target resonator 121 may be configured as a helix coil structure resonator, a spiral coil structure resonator, or a meta-structured resonator. The meta-structured resonator will be described in detail later with reference to FIG. 6.

Referring to FIG. 1, the control process of the cue-factor sets the resonance bandwidth of the source resonator 115 and the resonance bandwidth of the target resonator 121, and the source resonator 115 and the target resonator 121. And transferring electromagnetic energy from the source resonator 115 to the target resonator 121 through magnetic coupling therebetween. In this case, the resonance bandwidth of the source resonator 115 may be set to be wider or narrower than the resonance bandwidth of the target resonator 121. That is, since the resonance bandwidth of the source resonator 115 is set wider or narrower than the resonance bandwidth of the target resonator 121, the BW-factor of the source resonator and the BW-factor of the target resonator are maintained in an unbalanced relationship with each other. .

In resonant wireless power transmission, the resonance bandwidth is an important factor. When Qt is a Q-factor that considers the distance change between the source resonator 115 and the target resonator 121, the change in the resonance impedance, the impedance mismatch, the reflected signal, and the like, Qt is equal to the resonance bandwidth as shown in Equation 1 below. Have an inverse relationship.

[Equation 1]

는 대역폭,

는 공진기 사이의 반사 손실, BW_S는 소스 공진기(115)의 공진 대역폭, BW_D는 타겟 공진기(121)의 공진 대역폭을 나타낸다. 본 명세서에서 BW-factor는 1/ BW_S 또는 1/BW_D를 의미한다.In Equation 1, f0 is the center frequency,

Is the bandwidth,

Is the reflection loss between the resonators, BW _S is the resonance bandwidth of the source resonator 115, BW _D is the resonance bandwidth of the target resonator 121. In the present specification, the BW-factor means 1 / BW _S or 1 / BW _D.

On the other hand, impedance mismatching between the source resonator 115 and the target resonator 121 may occur due to external influences such as a change in distance between the source resonator 115 and the target resonator 121 or a change in one of the two positions. Can be. Impedance mismatch can be a direct cause of reducing the efficiency of power delivery. The matching control 113 may determine that impedance mismatch has occurred by sensing a reflected wave in which a part of the transmission signal is reflected and return, and perform impedance matching. In addition, the matching control 113 may change the resonance frequency by detecting the resonance point through the waveform analysis of the reflected wave. Here, the matching control 113 may determine a frequency having a minimum amplitude as the resonance frequency in the waveform of the reflected wave.

That is, the resonant power transmitter 110 may exchange not only power but also data with the resonant power receiver 120, and may simultaneously use the power transmission frequency band or use a separate independent frequency band. The resonance power receiver 120 receives power and supplies the load to the load. In this case, the energy field emitted from the resonance power transmitter 110 may have various unnecessary effects on the peripheral system.

2 is a diagram illustrating electromagnetic interference in a wireless power transmission system according to one side.

2 illustrates electromagnetic interference on a peripheral device in a wireless power transmission device and data exchange to solve the electromagnetic interference. The peripheral device measures electromagnetic interference affecting itself and reports data related to the electromagnetic interference to the wireless power transmitter so that the wireless power transmitter can adjust power. Here, the peripheral device refers to an electric device that receives electromagnetic interference directly or indirectly from the wireless power transmission device.

First, it is assumed that data communication is possible in the wireless power transmitter and the peripheral period. Peripheral devices periodically measure the electronic interference on them and monitor the measured results. The monitoring of the measured results may be performed by observing an abnormal value or observing a malfunction in the device by observing the strength of the current in the device and the amount of power consumed for the normal operation of the peripheral device. The peripheral device transmits information on the electromagnetic interference to the wireless power transmitter when an abnormality is observed as a result of monitoring the electromagnetic interference through the above method. The electromagnetic interference related information may include, for example, an electromagnetic interference (EMI) reduction request signal or location information of an electromagnetic interference (EMI) generator. In this case, for example, when the peripheral device determines that the electromagnetic interference has increased by more than a preset threshold, the electromagnetic interference (EMI) reduction request signal is transmitted. If not, you can use the method of not transmitting.

3 is a block diagram of an adaptive transmission power control apparatus for reducing electromagnetic interference in a wireless power transmission system according to one side.

Referring to FIG. 3, the adaptive transmission power adjusting apparatus includes a receiver 310, a power transmission controller 320, and a wireless transmitter 330.

The receiver 310 receives information related to electromagnetic interference from the peripheral device to the peripheral device. Peripherals periodically measure and monitor electromagnetic interference from wireless power transmitters. When the electromagnetic interference on the peripheral device exceeds a preset threshold, the peripheral device may transmit information related to the electromagnetic interference to the wireless power transmitter. Therefore, the receiver 310 receives information related to electromagnetic interference from the peripheral device. The information related to the electromagnetic interference may include an electromagnetic interference (EMI) reduction request signal or location information of the electromagnetic interference (EMI) generator.

In addition, the power transmission control unit 320 performs power transmission control considering electromagnetic interference based on information related to electromagnetic interference. The information related to the electromagnetic interference may include an electromagnetic interference reduction request signal from the peripheral device, location information of the peripheral device where electromagnetic interference occurs, and the like. The power transmission control unit 320 may perform power transmission control in various ways based on information related to electromagnetic interference. Various methods of performing power transmission control will be described in detail with reference to FIG. 4.

In addition, the wireless transmitter 330 wirelessly transmits information on power transmission control and power according to the control. The wireless transmitter 330 transmits information on the power transmission control used to reduce electromagnetic interference to the wireless power receiver. Here, the information about the power transmission control is a method applied by the power transmission control unit 320 to reduce the electromagnetic interference on the peripheral device, the change of the matching parameter, the change of frequency, the change by the frequency hopping method, the decrease of the transmission power, the transmission power Change in orientation, and the like. In addition, the information on the power transmission control may include a matching parameter constituting the wireless transmitter 330. The matching parameter may refer to physical element values related to impedance and reactance that form a resonance frequency of the wireless power transmitter.

In addition, the wireless transmitter 330 may transmit power or data to the wireless power receiver. In addition, the wireless transmitter 330 may move through the moving object and transmit power. That is, instead of performing wireless power transmission at a fixed position, power may be transmitted while moving in a predetermined area to be movable using a moving object. In this case, the movable body may include a robot device.

In addition, the peripheral device for transmitting the information related to the electromagnetic interference to the receiver 310 may include a measuring unit, determination unit, information transmission unit. The measurement unit may periodically measure electromagnetic interference on the peripheral device. In measuring electromagnetic interference, it is possible to measure the strength of the current in the device and the amount of power consumed necessary for the normal operation of the peripheral device. The determination unit may determine whether the electromagnetic interference increased by more than a threshold value set in the peripheral device with respect to the measured electromagnetic interference. For each peripheral device, a threshold for electromagnetic interference in a normal operable range may be preset. The information transmitter may transmit information related to the electromagnetic interference when the measured electromagnetic interference increases from the preset threshold. The information related to the electromagnetic interference may include an electromagnetic interference (EMI) reduction request signal or location information of the electromagnetic interference (EMI) generator.

4 is a block diagram of a power transmission control unit 320 according to one side.

Referring to FIG. 4, the power transmission control unit 320 includes a matching parameter change unit 410, a resonance frequency change unit 420, a frequency hopping scheme change unit 430, a transmission power reducer 440, and a change in the transmission power direction. It may include a portion 450.

The matching parameter changing unit 410 may change the matching parameter (impedance, reactance) constituting the wireless transmitter 330 to a value different from that currently used. The matching parameter refers to physical values related to the strength of the power currently transmitted from the wireless power transmission apparatus, the frequency causing resonance, the magnetic field emitted, and the like. For example, an impedance and a reactance component including a resistor, an inductor, and a capacitor of a circuit constituting the wireless transmitter 330 may be included. The matching parameter changing unit 410 may reduce the electromagnetic interference on the peripheral device and the amount of power transmission to the peripheral device as the matching parameter is changed.

In addition, the resonant frequency changing unit 420 may change the resonant frequency used for wireless power transmission to another resonant frequency. Changing the resonant frequency can reduce the electromagnetic interference and power transmission to the peripheral devices of the resonance phenomena that were weakly affecting the peripheral devices.

In addition, the frequency hopping scheme changing unit 430 may change the resonance frequency in a frequency hopping scheme in which the frequency is periodically changed according to a predetermined pattern with respect to the resonance frequency used for wireless power transmission. The constant pattern in frequency hopping may mean changing the frequency repeatedly with a predetermined bandwidth in a preset frequency band. The frequency hopping method may use a spread spectrum method. The frequency hopping method changing unit 430 may prevent the resonance frequency of a specific peripheral device from coinciding with the resonance frequency by changing the resonance frequency. In addition, security can be increased by allowing power to be transmitted only to a power receiving device that is authenticated by the same frequency hopping method in power transmission.

In addition, the transmission power reduction unit 440 may reduce the amount of power being wirelessly transmitted. The transmission power reduction unit 440 may reduce power transmitted to avoid unwanted power transmission to the peripheral device. The transmission power reduction unit 440 may reduce the amount of power received, thereby reducing the amount of power to the wireless power receiver for receiving power, and thus may be used when electromagnetic interference to a peripheral device is fatal.

In addition, the transmission power direction changing unit 450 may change the direction of the transmission power so as not to transmit power in the direction of the peripheral device affected by the electromagnetic interference based on the received information related to the electromagnetic interference. The information related to the electromagnetic interference may include information about the position and direction of the peripheral device subjected to the electromagnetic interference. The transmission power direction changing unit 450 may change the direction so that power is not transmitted in the direction of the peripheral device based on the information on the position and the direction of the peripheral device. In addition, the transmission power direction changing unit 450 transmits power through the secondary transmission device only when power transmission is requested from the wireless power receiver using the wireless power transmission device including the primary transmission device and the secondary transmission device. You can change the direction. At this time, the secondary transmitting apparatus may operate only the secondary transmitting apparatus that is located in a plurality of surroundings of the primary transmitting apparatus and receives power transmission from the wireless power receiving apparatus. In addition, the main transmitter and the sub-transmitter is connected to each other, when the transmitter receives a request for power transmission from the wireless power receiver, the secondary transmitter rotates in the direction of the wireless power receiver, the main transmitter is transmitted through the secondary transmitter Power may be transmitted to the wireless power receiver.

In addition, the control methods applied by the power transmission control unit 320 may be used independently of each other or several methods may be used sequentially. That is, the power transmission control unit 320 may apply the method of changing the frequency in consideration of the electromagnetic interference on the peripheral device after changing the matching parameter. If the control method is used sequentially, first the most efficient method is used, and then check again whether there is electromagnetic interference remaining in the peripheral device, and then use the next efficient method. Here, the efficient method means a method that is low in complexity, relatively inexpensive to implement in a wireless power transmission device, and maintains high power transmission and reception efficiency between wireless power transmission devices.

5 is a block diagram of an adaptive receiving power control apparatus for reducing electromagnetic interference in a wireless power transmission system according to one side.

Referring to FIG. 5, the adaptive reception power control apparatus includes a receiver 510, a matching unit 520, and a power receiver 530.

The receiver 510 receives information about a power transmission control applied to the wireless power transmitter, transmitted from the wireless power transmitter. The information on the power transmission control is applied to the power transmission control unit 320 in order to reduce the electromagnetic interference on the peripheral device, such as changing the matching parameter, the frequency, the frequency hopping method, the transmission power decrease, the transmission power direction It may include a change of.

In addition, the matching unit 520 controls the power receiver to match the scheme applied to the wireless power transmitter based on the information on the received power transmission control. Since the matching unit 520 may have various power transmission control schemes, the matching unit 520 controls the power receiver to be matched according to the power control scheme. Therefore, the matching unit 520 may match the impedance so as to receive the maximum power in response to the change of the matching parameter applied in the wireless power transmitter. In addition, the matching unit 520 may change the frequency of the power receiver to match the resonance frequency in response to the resonance frequency changed in the wireless power transmitter. In addition, the matching unit 520 may change the frequency of the power receiver in the same manner as the hopping scheme corresponding to the frequency hopping scheme in which the frequency is periodically changed according to a predetermined pattern applied in the wireless power transmitter. The matching unit 520 may continuously control power transmission and reception efficiency between power transmission and reception devices by controlling the power reception device to be matched with the transmission control method applied in the wireless power transmission device.

In addition, the power receiver 530 receives power from the wireless power transmitter based on the matched scheme. The power receiver 530 may continuously maintain power transmission and reception efficiency by receiving power from the wireless power transmitter in a matched state.

6 is a diagram illustrating a meta-structured resonator according to one side.

Referring to FIG. 6, the meta-structured resonator includes a transmission line 610 and a capacitor 620. Here, the capacitor 620 is inserted in series at a specific position of the transmission line 610, and the electric field is trapped in the capacitor.

In addition, as shown in FIG. 6, the meta-structured resonator has a form of a three-dimensional structure. Unlike the illustrated in FIG. 6, the resonator may be implemented in a two-dimensional structure in which transmission lines are arranged in x and z planes.

The capacitor 620 is inserted into the transmission line 610 in the form of a lumped element and a distributed element, for example, an interdigital capacitor or a gap capacitor centered on a substrate having a high dielectric constant. As the 620 is inserted into the transmission line 610, the resonator may have a metamaterial characteristic.

Here, the metamaterial is a material having special electrical properties that cannot be found in nature, and has an artificially designed structure. The electromagnetic properties of all materials in nature have inherent permittivity or permeability, and most materials have positive permittivity and 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, metamaterials are materials with a permittivity or permeability of less than 1, and according to the sign of permittivity or permeability, ENG (epsilon negative) material, MNG (mu negative) material, DNG (double negative) material, NRI (negative refractive index) Substances, and left-handed (LH) substances.

At this time, when the capacitance of the capacitor inserted as the lumped element is properly determined, the resonator may have the characteristics of the metamaterial. In particular, by appropriately adjusting the capacitance of the capacitor, the resonator may have a negative permeability, so that the resonator according to an embodiment of the present invention may be referred to as an MNG resonator.

The MNG resonator may have a zero-order resonance characteristic having a frequency when the propagation constant is 0 as a resonance frequency. Since the MNG resonator may have a zeroth resonance characteristic, the resonant frequency may be independent of the physical size of the MNG resonator. That is, as will be described again below, in order to change the resonant frequency in the MNG resonator, it is sufficient to design the capacitor appropriately, so that the physical size of the MNG resonator may not be changed.

In addition, in the near field, the electric field is concentrated on the series capacitor 620 inserted in the transmission line 610, so that the magnetic field is dominant in the near field due to the series capacitor 620.

In addition, the MNG resonator may have a high Q-factor by using the capacitor 620 as the lumped element, thereby improving the efficiency of power transmission.

In addition, the MNG resonator may include a matcher 630 for impedance matching. At this time, the matcher 630 properly tunable the strength of the magnetic field for coupling with the MNG resonator, and the impedance of the MNG resonator is adjusted by the matcher 630. The current flows into or out of the MNG resonator through the connector 640.

In addition, although not explicitly illustrated in FIG. 6, a magnetic core penetrating the MNG resonator may be further included. Such a magnetic core may perform a function of increasing a power transmission distance.

The characteristics of the MNG resonator of the present invention will be described in detail below.

FIG. 7 is a diagram illustrating an equivalent circuit of the resonator illustrated in FIG. 6.

The resonator shown in FIG. 6 may be modeled with the equivalent circuit shown in FIG. 7. In the equivalent circuit of FIG. 7, C _L represents a capacitor inserted in the form of a lumped element at the interruption of the transmission line of FIG. 6.

를 공진 주파수로 갖는다고 가정한다. 이 때, 공진 주파수

는 하기 수학식 2와 같이 표현될 수 있다. 여기서, MZR은 Mu Zero Resonator를 의미한다.At this time, the resonator for wireless power transmission shown in FIG. 6 has a zeroth resonance characteristic. That is, when the propagation constant is 0, the resonator for wireless power transmission

Suppose we have a resonant frequency. At this time, the resonance frequency

May be expressed as Equation 2 below. Here, MZR means Mu Zero Resonator.

[Equation 2]

는

에 의해 결정될 수 있고, 공진 주파수

와 공진기의 물리적인 사이즈는 서로 독립적일 수 있음을 알 수 있다. 따라서, 공진 주파수

와 공진기의 물리적인 사이즈가 서로 독립적이므로, 공진기의 물리적인 사이즈는 충분히 작아질 수 있다.
Referring to Equation 2, the resonant frequency of the resonator

Is

Can be determined by the resonant frequency

It can be seen that the physical size of the and the resonator may be independent of each other. Thus, resonant frequency

Since the physical sizes of the and resonators are independent of each other, the physical sizes of the resonators can be sufficiently small.

8 is a diagram illustrating a meta-structured resonator according to another side.

Referring to FIG. 8, the meta-structured resonator includes a transmission line unit 810 and a capacitor 820. In addition, the resonator according to an embodiment of the present invention may further include a feeding unit 830.

In the transmission line unit 810, a plurality of transmission line sheets are arranged in parallel. A configuration in which a plurality of transmission line sheets are arranged in parallel will be described in more detail with reference to FIG. 9.

The capacitor 820 is inserted at a specific position of the transmission line unit 810. In this case, the capacitor 820 may be inserted in series at the interruption of the transmission line unit 810. At this time, the electric field generated in the resonator is trapped in the capacitor 820.

The capacitor 820 may be inserted into the transmission line unit 810 in the form of a lumped element and a distributed element, for example, an interdigital capacitor or a gap capacitor centered on a substrate having a high dielectric constant. As the capacitor 820 is inserted into the transmission line unit 810, the resonator may have a metamaterial characteristic.

The feeding unit 830 may perform a function of supplying current to the MNG resonator. In this case, the feeding unit 830 may be designed to distribute the current supplied to the resonator evenly to the plurality of transmission line sheets.

9 is a view showing in detail the insertion position of the capacitor 820 of FIG.

Referring to FIG. 9, the capacitor 820 is inserted into an interruption portion of the transmission line unit 810. In this case, the interruption portion of the transmission line unit 810 may be open to allow the capacitor 820 to be inserted, and each of the transmission line sheets 810-1, 810-2, and 810-n may be open. It can be configured in the form of parallel to each other at the stop.

10 is a flowchart illustrating an adaptive transmission power adjusting method for reducing electromagnetic interference in a wireless power transmission system according to one side.

The wireless power transmission system includes a wireless power transmitter corresponding to a source and a wireless power receiver corresponding to a target.

In step 1010, the source receives information related to electromagnetic interference from the peripheral device to the peripheral device. The information related to the electromagnetic interference may include an electromagnetic interference (EMI) reduction request signal or location information of the electromagnetic interference (EMI) generator.

In operation 1020, the source performs power transmission control in consideration of electromagnetic interference based on the received information. The source may perform power transfer control in a variety of ways. Here, various methods of power transmission control are to reduce electromagnetic interference on a peripheral device, and include at least one of a matching parameter change, a frequency change, a frequency hopping method, a decrease in transmit power, and a change in transmit power direction. can do.

In addition, the control methods may be used independently or several methods may be used sequentially. That is, the performing of the power transmission control may include performing first power transmission control based on the received information related to the electromagnetic interference and performing information on the electromagnetic interference updated from the peripheral device as a result of performing the first power transmission control. Performing the second power transfer control based on the control method. Here, the method of performing the first power transmission control and the method of performing the second power transmission control may include a change of a matching parameter, a change of frequency, a change by a frequency hopping method, a decrease in transmit power, a change in transmit power direction, and the like. Can be. Thus, for example, the source may change the matching parameter constituting the wireless power transfer system to a value different from that currently used in the step of performing the first power transfer control. The source may receive information related to the updated electromagnetic interference from the peripheral for the changed value. In the step of performing the second power transmission control again, the source may change the resonant frequency used for the wireless power transmission to another resonant frequency based on the received information. In addition, the source may change the direction of the transmission power so that power is not transmitted in the direction of the peripheral device affected by the electromagnetic interference based on the information related to the received electromagnetic interference, and the information related to the electromagnetic interference updated from the peripheral device with respect to the changed value. The resonance frequency may be changed by a frequency hopping method in which frequency is changed periodically according to a predetermined pattern with respect to the resonance frequency used for wireless power transmission based on the received information. At this time, the peripheral device may periodically transmit information on the electromagnetic interference to the wireless power transmitter, thereby updating the information on the electromagnetic interference on the peripheral device.

In operation 1030, the source wirelessly transmits information on power transmission control and power according to the control. The source transmits information about the power transmission control used to reduce electromagnetic interference to the wireless power receiver.

In addition, the peripheral device that transmits the information about the electromagnetic interference to the source periodically measuring the electromagnetic interference on the peripheral device, and whether the electromagnetic interference has increased beyond the threshold set in the peripheral device for the measured electromagnetic interference The method may include determining and transmitting the information related to the electromagnetic interference when the measured electromagnetic interference increases from the preset threshold.

11 is a flowchart illustrating an adaptive transmission and reception power adjusting method for reducing electromagnetic interference in a wireless power transmission system according to one side.

11 illustrates a function occurring between a peripheral device, a wireless power transmitter, and a wireless power receiver over time.

When the wireless power transmitter transmits power to the wireless power receiver 1103, electrical devices around the wireless power transmitter may receive electromagnetic interference 1101. Peripheral devices subject to electromagnetic interference measure electromagnetic interference (EMI) (1105), and determine whether or not abnormality by monitoring the electromagnetic interference range of the generally acceptable range (1107). If there is an error, the peripheral device transmits information related to electromagnetic interference to the wireless power transmitter (1109). The wireless power transmitter controls the power transmission based on the information related to the electromagnetic interference, that is, the electromagnetic interference reduction request signal and the location information of the peripheral device. The power transmission control scheme may include a change of a matching parameter, a change of frequency, a change by a frequency hopping scheme, a decrease in transmit power, a change in a transmit power direction, and the like. The wireless power transmitter newly transmits power to the wireless power receiver 1117, and also transmits information on a power transmission control scheme so that the wireless power receiver continuously maintains the reception efficiency. In this case, since the wireless power transmitter may give electromagnetic interference to the peripheral device (1113), the peripheral device periodically measures the electromagnetic interference and determines whether there is an abnormality. The wireless power receiver maintains power and data reception efficiency by controlling the configuration 1119 to match the power transmission control scheme applied in the wireless power transmitter. When the wireless power transmitter receives an electromagnetic interference reduction request signal from a peripheral device, the wireless power transmitter may repeat the procedure. Accordingly, the wireless power transmitter adaptively can reduce / remove electromagnetic interference on the peripheral device by controlling the power transmission.

Methods according to an embodiment of the present invention can be implemented in the form of program instructions that can be executed by various computer means and recorded in a computer readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on the media may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts.

As described above, the present invention has been described by way of limited embodiments and drawings, but the present invention is not limited to the above embodiments, and those skilled in the art to which the present invention pertains various modifications and variations from such descriptions. This is possible.

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

Claims (19)

A receiver for receiving information related to electromagnetic interference from the peripheral device to the peripheral device;
A power transmission controller configured to perform power transmission control considering the electromagnetic interference based on the information related to the electromagnetic interference; And
Wireless transmission unit for wirelessly transmitting the information on the power transmission control and the power according to the control
Adaptive transmission power control device for reducing electromagnetic interference in a wireless power transmission system comprising a. The method of claim 1,
The information on the power transmission control includes a matching parameter constituting the wireless transmitter,
The power transmission controller changes the matching parameter to a value different from a value currently being used.
Adaptive transmission power control device for reducing electromagnetic interference in a wireless power transmission system comprising a. The method of claim 1,
The power transmission control unit,
Resonant frequency changing unit for changing the resonant frequency used for wireless power transmission to another resonant frequency
Adaptive transmission power control device for reducing electromagnetic interference in a wireless power transmission system comprising a. The method of claim 1,
The power transmission control unit,
Frequency hopping method changing unit for changing the resonant frequency in a frequency hopping method for periodically changing the frequency according to a predetermined pattern for the resonant frequency used for wireless power transmission
Adaptive transmission power control device for reducing electromagnetic interference in a wireless power transmission system comprising a. The method of claim 1,
The power transmission control unit,
Transmission power reduction unit for reducing the amount of power being transmitted wirelessly
Adaptive transmission power control device for reducing electromagnetic interference in a wireless power transmission system comprising a. The method of claim 1,
The power transmission control unit,
Transmitting power direction changing unit for changing the direction of the transmission power so as not to transmit power in the direction of the peripheral device affected by the electromagnetic interference based on the received information related to the electromagnetic interference
Adaptive transmission power control device for reducing electromagnetic interference in a wireless power transmission system comprising a. The method of claim 1
The wireless transmitter is an adaptive transmission power control apparatus for reducing electromagnetic interference in a wireless power transmission system, characterized in that for moving through a mobile to transmit power. The method of claim 1,
The peripheral device,
A measuring unit periodically measuring electromagnetic interference on the peripheral device;
A determination unit for determining whether the electromagnetic interference has increased by more than a threshold value set in the peripheral device with respect to the measured electromagnetic interference; And
An information transmitter for transmitting information related to the electromagnetic interference when the measured electromagnetic interference increases from the preset threshold.
Adaptive transmission power control device for reducing electromagnetic interference in a wireless power transmission system comprising a. A receiver configured to receive information on power transmission control applied to the wireless power transmitter, transmitted from the wireless power transmitter;
A matching unit controlling a power receiving device to be matched with a scheme applied to the wireless power transmitting device based on the received information; And
A power receiver configured to receive power from the wireless power transmitter based on the matched scheme
Adaptive receiving power control device for reducing electromagnetic interference in a wireless power transmission system comprising a. 10. The method of claim 9,
The matching unit,
Adaptive power control device for reducing electromagnetic interference in the wireless power transmission system, characterized in that for controlling the power receiver in the manner of impedance matching in response to the matching parameter changed in the wireless power transmission device. 10. The method of claim 9,
The matching unit,
Adaptive reception power control device for reducing electromagnetic interference in a wireless power transmission system for changing the frequency of the power receiving device to match the resonant frequency corresponding to the resonant frequency changed in the wireless power transmission device. 10. The method of claim 9,
The matching unit,
In order to reduce electromagnetic interference in a wireless power transmission system in which the frequency of the power receiving apparatus is changed in the same manner as the hopping scheme in response to a frequency hopping scheme that periodically changes the frequency according to a predetermined pattern applied by the wireless power transmitter. Adaptive Receive Power Control. Receiving information related to electromagnetic interference from the peripheral device to the peripheral device;
Performing power transmission control in consideration of the electromagnetic interference based on the received information; And
Wirelessly transmitting information on the power transmission control and power according to the control
Adaptive transmission power control method for reducing electromagnetic interference in a wireless power transmission system comprising a. The method of claim 13,
The performing of the power transfer control may include:
The wireless power transmission is performed by at least one of changing a matching parameter, changing a resonance frequency, changing a resonance frequency by a hopping method of a frequency, reducing a transmission power, and changing a transmission power direction. Adaptive transmission power regulation method for reducing electromagnetic interference in a system. The method of claim 14,
The performing of the power transfer control may include:
Performing a first power transfer control based on the information related to the received electromagnetic interference; And
Performing second power transfer control based on information related to electromagnetic interference updated from the peripheral device as a result of performing the first power transfer control;
Adaptive transmission power control method for reducing electromagnetic interference in a wireless power transmission system comprising a. 16. The method of claim 15,
The performing of the first power transmission control may include changing a matching parameter constituting the wireless power transmission system to a value different from a current value,
The performing of the second power transmission control may include changing a resonant frequency used for wireless power transmission to another resonant frequency based on updated information related to electromagnetic interference.
Adaptive transmission power control method for reducing electromagnetic interference in a wireless power transmission system, characterized in that. 16. The method of claim 15,
The performing of the first power transmission control may include changing a direction of transmission power so that power is not transmitted in a direction of a peripheral device affected by the electromagnetic interference based on the received information related to the electromagnetic interference,
The performing of the second power transmission control may include performing resonance in a frequency hopping manner in which frequency is periodically changed according to a predetermined pattern with respect to a resonant frequency used for wireless power transmission based on updated information related to electromagnetic interference. Changing frequency
Adaptive transmission power control method for reducing electromagnetic interference in a wireless power transmission system, characterized in that. The method of claim 13,
The peripheral device,
Periodically measuring electromagnetic interference on the peripheral device;
Determining whether the electromagnetic interference increases with respect to the measured electromagnetic interference by more than a threshold value set in the peripheral device; And
Transmitting the information related to the electromagnetic interference when the measured electromagnetic interference increases from the preset threshold
Adaptive transmission power control method for reducing electromagnetic interference in a wireless power transmission system comprising a. Receiving information on power transmission control applied to the wireless power transmitter, transmitted from the wireless power transmitter;
Controlling a power receiving device to be matched to a scheme applied to the wireless power transmitter based on the received information; And
Receiving power from the wireless power transmitter based on the matched scheme
Adaptive receive power control method for reducing electromagnetic interference in a wireless power transmission system comprising a.

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