KR101173947B1 - Method of sending switching instruction in multi-node wireless power transmission - Google Patents

Abstract

The present invention relates to a multi-node wireless power transmission system and a wireless charger using a magnetic resonance induction method capable of selectively charging a plurality of wireless chargers, the wireless power transmission device receives information from a plurality of wireless chargers On the basis of this information, the power receiving function of the wireless charger is turned on / off using an adaptive matching network that selects a target device to be charged and controls or adjusts a switch installed in the power converter of the wireless charger. do. Accordingly, only the power receiving function can be controlled ON / OFF while maintaining the power of other wireless chargers other than the device to be charged, thereby enabling selective charging and simultaneously using the wireless chargers waiting for charging without inconvenience.

Description

Method of sending switching instruction in multi-node wireless power transmission

The present invention relates to a wireless power transmission method, and more particularly, to a multi-node wireless power transmission method using a magnetic resonance induction method capable of selectively charging a plurality of wireless chargers.

As a wireless power transmission technology for wirelessly transmitting energy, a wireless charging system using magnetic induction is used.

For example, electric toothbrushes or wireless shavers are charged with the principle of electromagnetic induction. Recently, wireless charging products for charging mobile devices such as mobile phones, PDAs, MP3 players, and notebook computers using electromagnetic induction have been introduced. .

However, the magnetic induction method of inducing current through a magnetic field from one coil to another is very sensitive to the distance and relative position between the coils, so that the transmission efficiency drops rapidly even if the distance between the two coils is slightly dropped or twisted. Accordingly, this magnetic induction charging system can only be used in a short distance of several cm or less.

On the other hand, US Patent 7,741,735 discloses a non-radiative energy transfer method based on the attenuation wave coupling of the resonant field. This is because two resonators with the same frequency do not affect other non-resonators around them, but they tend to couple with each other and are introduced as a technology that can transfer energy over a long distance compared to conventional electromagnetic induction. .

SUMMARY OF THE INVENTION The present invention has been made in the technical background as described above, and an object thereof is to provide a multi-node wireless power transmission method of a self-resonance induction method capable of selectively charging a plurality of wireless chargers.

In order to solve the above problems, in the present invention, a switch is installed in the power converter of the wireless charger to turn on / off the corresponding switch to turn on / off the power receiving function of the wireless charger.

The wireless charging method according to an aspect of the present invention is a method of transmitting power by a wireless power supply device in a self-resonance induction method, the identification information, type information, location information and charging of the wireless charger from at least one wireless charger Receiving at least one piece of status information; Selecting a device to be charged from the at least one wireless charger based on the at least one information; Transmitting an ON command for activating a wireless power reception function to the selected charging target device; Transmitting an OFF command to the remaining wireless charger to block the wireless power reception function; And transmitting wireless power to the at least one wireless charger based on a magnetic resonance induction scheme.

Here, when receiving the ON command, the selected charging target device may perform frequency matching with the wireless power supply.

In addition, when receiving the OFF command, the remaining wireless charger may not perform frequency matching with the wireless power supply.

According to the present invention, in a multi-node wireless power transmission system using a magnetic resonance induction method, the wireless power transmitter receives information from a plurality of wireless chargers and selects and charges a target device to be charged based on the information. Can control the group.

In addition, since only the power receiving function can be controlled ON / OFF while maintaining the power of other wireless chargers other than the charging target device, wireless chargers waiting for charging can be used without inconvenience.

1 is a block diagram schematically showing the overall configuration of a multi-node wireless energy transmission system using a magnetic resonance induction method according to an embodiment of the present invention.
2 is a block diagram schematically showing the overall configuration of a wireless charger according to an embodiment of the present invention.
3 is a flowchart illustrating a selective charging method according to an embodiment of the present invention.
4, 5, and 7 are block diagrams illustrating the configuration of a power management unit of the wireless charger according to various embodiments of the present invention, respectively.
6 is a diagram illustrating a configuration of a receiving antenna and an adaptive matching network according to an embodiment of the present invention.
8 is a block diagram illustrating a configuration of a receiving antenna unit of a wireless charger according to another embodiment of the present invention.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the present embodiments are intended to complete the disclosure of the present invention, and the general knowledge in the art to which the present invention pertains. It is provided to fully convey the scope of the invention to those skilled in the art, and the present invention is defined only by the scope of the claims. It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. As used herein, “comprises” and / or “comprising” refers to the presence of one or more other components, steps, operations and / or elements. Or does not exclude additions.

Hereinafter, a multi-node wireless energy transmission system using a magnetic resonance induction method according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, a multi-node wireless energy transmission system using a magnetic resonance induction method according to an embodiment of the present invention includes a wireless power supply device 100 that wirelessly supplies power through a magnetic resonance induction method, and wireless power. Located a distance away from the supply device 100 by a predetermined distance and comprises a plurality of wireless chargers (200_1, 200_2, ..., 200_N) that is wirelessly supplied power from the wireless power supply (100).

Magnetic resonance induction is a method of maximizing the wireless transmission efficiency of energy by the resonance between the transmitting antenna and the receiving antenna. To this end, a resonance channel is formed between the wireless power supply device 100 and the wireless charger 200 to form a resonant channel and transmit wireless power therethrough.

The wireless power supply device 100 includes a wireless charger 200_1, 200_2, including identification information, type, location, or state of charge of the charger through magnetic field communication with the wireless charger 200_1, 200_2, .., 200_N. ..., 200_N) may be received, and power may be transmitted to the wireless chargers 200_1, 200_2,..., 200_N based on the charging information.

The wireless power supply device 100 may be implemented as a fixed type or a mobile type. When the wireless power supply device 100 is implemented as a fixed type, the wireless power supply device 100 may be installed in a furniture such as a ceiling or a table indoors. In addition, the wireless power supply device 100 may be installed inside a moving object such as a vehicle, a train, a subway. When the wireless power supply 100 is implemented as a mobile, the wireless power supply 100 itself may be implemented as a separate mobile device, or may be implemented as part of another digital device such as a cover of a notebook computer. .

The wireless chargers 200_1, 200_2, .., 200_N may include all digital devices including batteries such as various mobile terminals, digital cameras, and notebook computers, and are not easily accessible from underground, underwater, and inside buildings. It may also be an electronic device such as a sensor and a measuring instrument.

Now, a configuration of the wireless charger of the multi-node wireless energy transmission system using the magnetic resonance induction method according to an embodiment of the present invention will be described in more detail with reference to FIG. 2.

As shown in FIG. 2, the wireless charger 200 receives a power and data from a wireless power supply device 100 using a magnetic resonance induction method, and a wireless power supply using a magnetic field communication protocol. The components of the wireless charger 200, including the magnetic field communication modem 230 for performing magnetic field communication with the device 100, the power management unit 220 for managing power reception, the power management unit and the magnetic field communication modem 230, The control unit 240 to control, including the battery 250 is charged using the received power.

3 is a flowchart of a method for selectively charging each wireless charger in a multi-node wireless energy transfer system using a magnetic resonance induction method according to an embodiment of the present invention.

As shown in FIG. 3, first, when the wireless power supply device 100 is turned on (S310), identification information of the charger is received from each of the wireless chargers 200_1, 200_2,..., 200_N (S320). At this time, in addition to the identification information of the charger may be further received information such as the type, location, or state of charge of the charger.

Next, the wireless power supply device 100 selects a device to be charged (S330). The charging target device may be selected in various ways, and one or more charging target devices may be selected.

When the device to be charged is selected, the wireless power supply device 100 transmits an ON / OFF command to each wireless charger (S340). According to the received ON / OFF command, each wireless charger turns on / off the power receiving function, and the wireless power supply device 100 selectively transmits power as it transmits power (S350).

Instead of turning off the power to the wireless charger that is not selected as the charging target device, only the power reception function can be turned off to effectively implement a multi-node wireless energy transmission system. That is, when selectively charging only one of a plurality of wireless chargers included in the multi-node wireless energy transmission system, when the power of the charger is cut off to prevent charging to another wireless charger, the corresponding wireless charger itself Compared to the use of the present invention, it is very inconvenient to use it, and thus, such a inconvenience can be eliminated in the case of selective charging by turning off only the power reception function as in the embodiment of the present invention.

To this end, the embodiment of the present invention controls the ON / OFF of the power reception function through the circuit control of the receiver (wireless charger). Now, the configuration of the power management unit provided in each wireless charger of the multi-node wireless energy transfer system using the magnetic resonance induction method according to an embodiment of the present invention will be described in detail.

4 to 6 are block diagrams illustrating various configurations of the power management unit of the wireless charger according to the embodiment of the present invention.

First, referring to FIG. 4, the power manager 220_1 includes a matching network 221, a rectifier 222, a power control switch 223, and a DC-DC converter 224. The DC-DC converter 224 is connected to a load (FIG. 2: 250), that is, a battery, etc. outside the power manager 220_1, and the power control switch 223 is connected to the controller (FIG. 2: 240) to control the controller (FIG. 2). : It operates by receiving ON / OFF switching signal from 240).

The matching network 221 adjusts the frequency so that the wireless power supply device 100 and the wireless charger 200 resonate, and performs impedance matching between the reception antenna 210 and the wireless charger 200.

The RF power received through the matching network 221 is converted into DC power through the rectifier 222, the DC-DC converter 224 converts it to a voltage for each load and provides it. That is, the rectifier 222 and the DC-DC converter 224 correspond to a power converter that converts the received RF power into DC power suitable for each load.

Here, the power control switch 223 is located between the rectifier 222 and the DC-DC converter 224, by turning on / off this power control switch 223 to turn on the charging function of the wireless charger 200. You can / OFF.

That is, when the power control switch 223 is ON, the received power is transferred to the load through the rectifier 222 and the DC-DC converter 224, but when the power control switch 223 is OFF, the received power is cut off. Since it is not consumed in the wireless charger 200, the energy corresponding to the received power is bounced back to other wireless chargers around to be used to charge another wireless charger.

FIG. 5 shows a configuration of a power management unit according to another embodiment. In the embodiment shown in FIG. 5, a switch is installed in a matching network instead of a power control switch between a rectifier and a DC-DC converter.

Referring to FIG. 5, in the power manager 220_2 according to another embodiment of the present invention, instead of the matching network 221 shown in FIG. 4, an adaptive matching network 225 capable of adjusting frequency matching as needed. ). That is, the power manager 220_2 includes an adaptive matching network 225, a rectifier 222, and a DC-DC converter 224. The DC-DC converter 224 is connected with a load (Fig. 2: 250) as in the embodiment of Fig. 4.

The configuration of the adaptive matching network 225 is shown in detail in FIG.

The adaptive matching network 225 may change the capacitance of the entire adaptive matching network 225 by connecting additional capacitors 227 in parallel to the matching circuit to switch connections with the corresponding capacitor 227. Among the matching circuits, Cr is a capacitor for matching resonance with the wireless power supply device 100, and Cm is a capacitor for impedance matching. In addition, the capacitor Ct 227 for adjusting the resonance frequency is further connected and controlled using the switch 226.

That is, since the adaptive matching network 225 is configured to perform frequency matching with the wireless power supply device 100 when the switch 226 is turned off, the receiving antenna 210 is connected from the wireless power supply device 100. Receives wireless power and delivers it to rectifier 222. On the contrary, since the frequencies of the wireless power supply 100 and the wireless charger 200 do not match when the switch 226 is in an ON state, resonance does not occur between the wireless power supply 100 and the wireless charger 200. .

On the other hand, by adjusting the capacitance of the capacitor 227, the function as the charge function ON / OFF switch can be optimized. In order to cut off most of the power transmitted by the wireless power supply device 100, it is preferable that the capacitor 227 has a capacity of 2 to 10 times the capacitance of the matching circuit.

If necessary, both adaptive matching networks and power disconnect switches can be used. 7 shows such an embodiment.

As shown in FIG. 7, the power manager 220_3 includes an adaptive matching network 225, a rectifier 222, a power cutoff switch 223, and a DC-DC converter 224. In this case, only the switch 226 or the power cutoff switch 223 in the adaptive matching network 225 may be used as needed, or both switches 226 and 223 may be used.

Meanwhile, the reception antenna 210 of the wireless charger 200 may be implemented with various antennas including a loop antenna, or may include two or more coils having two different frequencies.

8 is a diagram illustrating a configuration of a receiving antenna of a wireless charger according to another embodiment of the present invention.

As shown in FIG. 8, the wireless charger according to the embodiment of the present invention may include a high frequency coil 212 and a low frequency coil 211 as the receiving antenna 210. Both the high frequency coil 212 and the low frequency coil 211 can receive the power transmitted by the wireless power supply 100 in a self-resonant induction manner, and the high frequency coil 212 and the low frequency coil 211 for wireless power reception. ) Can be used or two can be used simultaneously.

On the other hand, it is preferable to use the low frequency coil 211 for data communication using the magnetic field with the wireless power supply device 100.

Accordingly, the high frequency coil 212 and the low frequency coil 211 are connected with the power management unit (FIG. 2: 220), and the low frequency coil 211 is also connected with the magnetic field communication modem (FIG. 2: 230).

When the reception antenna 210 of the wireless charger 200 is implemented by the high frequency coil 212 and the low frequency coil 211, the wireless power supply device 100 also includes a high frequency coil and a low frequency coil. It is preferable to have. In particular, a multiaxial three-dimensional coil can be used as the transmitting antenna, and accordingly, a high frequency multiaxial three-dimensional coil and a low frequency multiaxial three-dimensional coil can be used for the transmitting antenna. The bandwidth of the magnetic field signals transmitted through the high frequency multiaxial stereoscopic coil and the low frequency multiaxial stereoscopic coil are different from each other, and the magnetic field signals having different bandwidths are transmitted to the wireless charger 200 to be charged in the dual mode (high frequency band and low frequency band). You can also do The low frequency mode is advantageous for charging a wireless charger in a long distance, and the high frequency mode is closer to a charging distance than the low frequency mode, and can be used when charging to increase charging efficiency.

According to the embodiment of the present invention as described above, in the multi-node wireless power transmission system using the magnetic resonance induction method, the target device that the wireless power transmission device receives information from a plurality of wireless chargers to charge based on the information You can control the wireless charger to select and charge. In addition, since only the power receiving function can be controlled ON / OFF while maintaining the power of other wireless chargers other than the charging target device, wireless chargers waiting for charging can be used without inconvenience.

Although the present invention has been described above with reference to preferred embodiments, the apparatus and method of the present invention are not necessarily limited to the above-described embodiments, and various modifications and variations can be made without departing from the spirit and scope of the invention. Accordingly, the appended claims will include such modifications and variations as long as they fall within the spirit of the invention.

100: wireless power transmitter 200: wireless charger
210: receiving antenna 220: power management unit
230: magnetic field communication modem 240: control unit
250: load 221: matching network
222: rectifier 223: power control switch
224: DC-DC converter 225: adaptive matching network

Claims (3)

Wireless power supply is a method of transmitting power in a magnetic resonance induction method,
Receiving at least one of identification information, type information, location information, and charging state information of the wireless charger from at least one wireless charger;
Selecting a device to be charged from the at least one wireless charger based on the at least one information;
Transmitting an ON command for activating a wireless power reception function to the selected charging target device;
Transmitting an OFF command to the remaining wireless charger to block the wireless power reception function; And
Transmitting wireless power to the at least one wireless charger based on a magnetic resonance induction method,
The wireless charger,
A reception antenna for receiving wireless power transmitted from the wireless power transmission device;
A rectifier for rectifying power supplied through the receiving antenna;
A power control switch connected to a rear end of the rectifier;
A DC-DC converter having one end connected to the power control switch and the other end connected to a load;
A matching network connected to the receiving antenna,
The matching network,
A matching circuit for matching a resonance frequency between the wireless power transmitter and the wireless charger;
A power control capacitor connected in parallel with the matching circuit;
And a matching switch having one end connected to the matching circuit and the other end connected to the power control capacitor. The method of claim 1,
And receiving the ON command, the selected charging target device performs frequency matching with the wireless power supply. The method of claim 1,
And receiving the OFF command, wherein the remaining wireless charger does not perform frequency matching with the wireless power supply.

Images