KR101837546B1 - Multi-device wireless power transmission system - Google Patents

Abstract

A multi-node wireless power transmission system comprising a wireless power transmission device and a plurality of wireless charging devices spaced apart from the wireless power transmission device, wherein when the wireless charging device is located in a semi-charging zone where communication is possible, Determining whether the wireless charging device is a target of a wireless power transmission service based on an ID received from the wireless charging device, and when the wireless charging device is located in a charging zone capable of both communication and wireless power transmission, Wherein the wireless power transmission service can be provided in a simultaneous power transmission mode or a time sharing power transmission mode.

Description

[0001] Multi-device wireless power transmission system [0002]

The present invention relates to a multi-device wireless power transmission system, and more particularly to a multi-device wireless power transmission system having an interface for controlling wireless power transmission to multiple devices.

A wireless charging system using a magnetic induction phenomenon is being used as a wireless power transmission technology for transferring energy wirelessly.

For example, an electric toothbrush or a wireless shaver is charged with the principle of electromagnetic induction, and recently, wireless charging products capable of charging a portable device such as a mobile phone, a PDA, an MP3 player, and a notebook computer by using electromagnetic induction have been introduced .

However, the magnetic induction method of inducing a current from one coil to another through a magnetic field is very sensitive to the distance between the coils and the relative position thereof, so that the transmission efficiency is rapidly deteriorated even if the distance between the two coils is slightly decreased or turned. Accordingly, such a magnetic induction type charging system has a weak point that it can be used only at a short distance of a few cm or less.

On the other hand, U.S. Patent No. 7,741,735 discloses a non-radiation energy transfer method based on attenuation wave coupling of a resonance field. This is because the resonator with two identical frequencies has a tendency to be coupled to each other without affecting other surrounding non-resonators, and this technique has been introduced as a technology capable of transmitting energy to a far distance as compared with the conventional electromagnetic induction .

SUMMARY OF THE INVENTION The present invention has been made in view of the above technical background, and it is an object of the present invention to provide a multi-device wireless power transmission system having an interface for controlling wireless power transmission to multiple devices.

In order to solve such problems, the present invention defines requirements of an interface for controlling wireless power transmission to a plurality of devices, and provides protocols and procedures of a control interface.

That is, a multi-device wireless power transmission system according to an aspect of the present invention is a multi-node wireless power transmission system including a wireless power transmission device and a plurality of wireless charging devices spaced apart from the wireless power transmission device, The wireless power transmitter determines whether the wireless charger is the target of the wireless power transmission service based on the ID received from the wireless charging device, and the wireless charger determines whether the wireless charger is both a communication and a wireless power transmission The wireless charging device may provide a wireless power transmission service to the wireless charging device when the wireless charging device is located in a charging zone as much as possible, and the wireless power transmission service may be provided in a simultaneous power transmission mode or a time sharing power transmission mode.

According to the present invention, the requirements of the interface for controlling the wireless power transmission to multiple devices are defined, and the protocols and procedures of the control interface are provided so that the multi-device wireless power transmission system can be properly operated.

1 is a diagram illustrating an outline of a wireless power transmission implemented in a multi-device wireless power transmission system according to an embodiment of the present invention.
2 is a diagram illustrating physical / spatial components of a multi-device wireless power transmission system in accordance with an embodiment of the present invention.
3 is a diagram illustrating physical / spatial components of a multi-device wireless power transmission system in accordance with an embodiment of the present invention.
4 is a diagram illustrating a structure of a frame including data for wireless power transmission control according to an embodiment of the present invention.
FIG. The contents for type are shown.
Figure 6 shows the size and description of each field.
Figure 7 is a procedure of power receiver identification / authentication, charging zone / semi-charging zone.
8 is a procedure of simultaneous power transmission.
9 is a procedure of time division power transmission.
10 is a procedure for removing foreign matter.
11 is a procedure according to the appearance of a new power receiver and disappearance of a conventional power receiver.
Fig. 12 is a flowchart of a buffering method for a conventional power receiver.
FIG. 13 is a flowchart illustrating a procedure for terminating power transmission.
14 is a procedure of power transmission between apparatuses.
15 shows a basic structure of a power transmitter.
16 shows a basic structure of a power receiver.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined 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. It is noted that the terms "comprises" and / or "comprising" used in the specification are intended to be inclusive in a manner similar to the components, steps, operations, and / Or additions.

Hereinafter, a multi-device wireless power transmission system according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1. Overview

A wireless power transmission network is a system for efficiently supplying power wirelessly to a plurality of power receivers, and is composed of one power transmitter and a plurality of power receivers. In order to efficiently transmit and control power to a plurality of power receivers, a control interface that can manage a complicated wireless power transmission network compared with a 1: 1 wireless power transmission is indispensable. ID recognition, authentication, etc., and selects the power transmission mode of each device based on the exchanged power transmission information, and the procedure and interface for controlling and managing the unexpected situation such as the response to the sudden disappearing or emerging power receiver Must be accompanied.

1 is a diagram illustrating an outline of a wireless power transmission implemented in a multi-device wireless power transmission system according to an embodiment of the present invention.

There is also a need for a wireless communication system capable of exchanging power transmission information and control signals. Time-division-based scheduling, and the power transmitter manages the joining, demultiplexing and demultiplexing of the power receivers for wireless power transmission environment control.

Provides power transmission function from several W to several hundred watts depending on the type of power receiver, including contact, within a few meters within a short distance and guarantees more than 70% efficiency over the required wireless power transmission distance of each power receiver Should be.

In order to efficiently transmit radio power, a frequency of a low frequency (30 to 300 kHz, LF) having a relatively wide radio power transmission bandwidth and a frequency of a medium frequency (300 kHz to 30 MHz, MF) Is designed so that the influence of the interference of two bands is less than -30 dB when the antenna is designed.

A network using in-band magnetic field communication to exchange information and control signals in a wireless power transmission network uses the same frequency as wireless power transmission in wireless communication within the LF magnetic field region to increase the efficiency of frequency use.

Wireless power transmission networks are divided into physical components, temporal components and spatial components. The physical component is a network composed of a power transmitter and a power receiver. The temporal component is composed of a superframe consisting of a request interval, a response interval, and an inactive interval. The space factor is divided into a charging zone and a semi-charging zone do.

A physical component that constitutes a wireless power transmission network is a node that includes a power transmitter and a power receiver in a star topology network centered on a power transmitter. A wireless power transmission network is a network capable of data communication and wireless power transmission with respective power receivers around a power transmitter. The power transmitter manages the entire wireless power transmission network and there is only one in the network. 2 is a diagram illustrating physical / spatial components of a multi-device wireless power transmission system in accordance with an embodiment of the present invention.

In order to manage effective power receivers, a basic preparatory procedure for wireless power transmission must be preceded by recognizing and authenticating power receivers in advance in a communicable area and exchanging data necessary for wireless power transmission. Accordingly, there is a virtual space divided into a charging zone and a semi-charging zone. The power transmitter starts to manage power receivers in the semi-charging zone, which is a communication area, And performs actual wireless power transmission to the belonging power receivers.

In case of using in-band magnetic field communication, spatial charging zone and semi-charging zone can efficiently form because of magnetic field characteristic that can not exist to a long distance. However, when using other communication method, In order to prevent this from happening, it is necessary to adjust the output power of other communication methods in the power transmitter.

The wireless power transmission network uses a time division multiple access (TDMA) scheme, which is managed by a power transmitter and distributed by the power receiver's request and the power transmitter's judgment.

The power transmitter collects information related to the power transmission from the power receiver for efficient time-division-based wireless power transmission, and completes the scheduling based on the information. The power transmitter informs the power receivers of the scheduling information so that the power receivers can receive the power at the appropriate time, thereby preventing duplicate power reception.

A time factor that can be utilized in a wireless power transmission network is a time slot in a time division multiple access scheme. The power transmitter can manage a group of power receivers capable of transmitting data in the response interval and the time slots are autonomously managed by the power receivers in the selected group of networks. The superframes of the wireless power transmission communication convergence network are composed of three superframes as shown in Fig. An Association Request superframe, a Powering Requirement Request superframe, and a Powering Preparation Request superframe. The length of each request interval and response interval is variable. The superframe of the wireless power transmission network is initiated by the power transmitter sending a response request packet in the request interval of the superframe requesting the join request. The response request packet has information on power receivers capable of transmitting a response packet during the response interval, and the power receivers transmit the response packet during the response interval using the information in the response request packet.

3 is a diagram illustrating temporal components of a multi-device wireless power transmission system according to an embodiment of the present invention.

2. Definition of Wireless Power Transmission Control Interface Requirements

A. General Information

In order to perform a wireless power transmission to a plurality of power receivers, a power receiver recognition / authentication procedure for determining whether the power receiver recognized by the power transmitter is a device suitable for providing a wireless power transmission service is a priority.

In order to provide wireless power transmission to a plurality of power receivers quickly, it is generally necessary for the power receiver to recognize and authenticate the power receiver and to transmit the power for wireless power transmission when it is in a semi-charging zone where wireless communication is possible The base data is exchanged to complete the wireless power transmission preparation. When the ready-made power receiver enters the charging zone, the wireless power transmission is performed to save the preparation time for the wireless power transmission to provide quick service.

In order to efficiently provide the wireless power transmission service, the wireless power transmission mode is simultaneously performed to all the devices in the charging zone according to the situation, and the priority is set based on the battery power level or the user selection basis. There is a time division power transfer mode for performing power transmission.

When all of the power receivers are full, the power transmission may be terminated or the user may arbitrarily stop the currently provided power transmission service.

There are frequent and varying incidents that must be considered for wireless power transmission to multiple power receivers. In order to efficiently cope with this problem, when an unexpected situation occurs on the network during the wireless power transmission, the power transmitter recognizes this and stops the wireless power transmission service until the unexpected situation is processed, thereby informing the user of the unexpected situation.

B. Power receiver recognition / authentication

The power transmitter periodically transmits communication signals in the entire Superframe, and the power receivers receiving the signals transmit their IDs in response. The power transmitter determines whether the corresponding power receivers are the target of the wireless power transmission service based on the received ID, and requests information about the wireless power transmission to the corresponding power receiver if the target is the service target. And informs the non-service power receiver that it can not provide the service.

C. Charging Zone / Semi-Charging Zone

The charging zone and the semi-charging zone are the spatial elements of the wireless power transmission network, and the area where communication is possible is the semi-charging zone, and the area where both communication and wireless power transmission is possible is the charging zone. Service provisioning in the semi-charging zone to efficiently and rapidly provide wireless power transmission services to multiple power receivers After the preparation of the wireless power transmission is completed through the exchange of information necessary for power receiver recognition and power transmission, It is separated to carry out the power transmission service.

D. Wireless power transfer mode

1) Simultaneous power transmission mode

After the recognition of the power receiver and the exchange of information necessary for power transmission is completed, the wireless power transmission service is started. The simultaneous power transmission mode during wireless power transmission is a mode in which wireless power is simultaneously transmitted to power receivers that need to provide all services present in the charging zone. In order to increase the efficiency of wireless power transmission, the voltage / current flowing through the antenna is sensed and the resonance frequency is controlled based on the sensed voltage / current. Further adjustment is performed by calculating the efficiency after receiving the reception power through communication. Once the resonant frequency is adjusted, the receiver performs simultaneous wireless power transmission to all power receivers, which continues until the end of the wireless power transmission.

2) Time division power transmission mode

After the recognition of the power receiver and the exchange of information necessary for wireless power transmission is completed, the wireless power transmission service is started. The time-sharing power transmission mode during the wireless power transmission is a mode in which the wireless power transmission is separately transmitted for each power receiver for a given time by dividing the allocated time in priority to the power receivers requiring all the services present in the charging zone . A wireless power transmission service is provided only for the allocated time for each power receiver, and is terminated when all power receivers are serviced.

E. Unexpected situation

If an unexpected situation occurs during the wireless power transmission service, stop the service and resolve the unexpected situation. The unexpected situation can be classified into foreign matter detection, the emergence of new power receivers and the disappearance of existing power receivers, and the exiting due to the buffering of existing power receivers. All unexpected situations are detected by sensing the change in voltage / current flowing from the power transmitter to the antenna, recognizing the situation more precisely through communication, and then performing actions according to each situation.

1) Detect foreign matter

When a foreign substance that changes the efficiency of the wireless power transmission appears, it recognizes it and notifies the user of the presence of the foreign substance in the form of an alarm.

2) The emergence of new power receivers and the disappearance of existing power receivers

When a new power receiver appears or the existing power receiver disappears, it detects the resonance frequency that can maximize the efficiency of the wireless power transmission again and resumes the wireless power transmission service again.

3) Buffering of existing power receiver

When the power receiver receiving the wireless power transmission service is buffered, the service is blocked and informs the power transmitter of the buffer through communication. The power transmitter resumes the wireless power transmission service to the remaining power receivers without considering the power receiver after receiving the buffer information.

F. End of wireless power transmission

The termination of the wireless power transmission is divided into a case where there is no power receiver to provide the wireless power transmission service and a case where the user desires to shut down. The presently provided wireless power transmission service is terminated and the power transmitter is put into the standby mode.

G. Power receiving period wireless power transmission

If there is no power transmitter or the power receiver is not in the charging zone, it may request a wireless power transmission to the adjacent power receiver. Upon receiving the request, the power receiver may transmit the wireless power to the requesting power receiver depending on the user's selection.

3. Wireless Power Transmission Control Interface Protocol

A. General Information

Information to be exchanged in order to efficiently perform wireless power transmission, and data for wireless low power transmission network control and management between the power transmitter and the power receiver is defined in the form of a frame, and the actually transmitted message is defined.

B. Frame Type

1) Frame structure

A frame including data for wireless power transmission control is composed of elements as shown in Fig. Through the frame consisting of the structure as shown in the figure, the power transmitter transmits the control command to the power receiver, and the power receiver transmits the power transmission information to the power transmitter.

2) Field Description

The START field consists of one byte and represents the beginning of one frame and has a fixed value of 0x7E.

The CODE field consists of 1 byte and is assigned code for each message type to distinguish the transmitted message. For more information, see C. Message Definitions.

The Control Field consists of 1 byte and provides PALOAD message type information, frame number information for each code, and PAYLOAD length information. The structure of the control field is as follows.

o. msg . typ (message type, 2-bit wide: bit # 7 - # 6)

Provide information about whether Payload is request / response and command / data.

- bit # 7: 0 = REQ, 1 = RESP

- bit # 6: 0 = CMD, 1 = DATA

FIG. The contents for type are shown.

o. seq . num . (sequence number, 2-bit wide bit # 5- # 4)

Sequential numbers are assigned to each consecutive CODE frame in order to prevent frames lost during message transmission.

o. pl . lng . (payload length, 4-bit wide bit # 3 - # 0)

The length of the PAYLOAD following the Control in bytes.

PAYLOAD Field has a variable length of 0 to 15 bytes and contains actual data to be transferred. See C. Message Definition for details.

The CRC field consists of one byte and is used to determine whether the frame body has been received without error. The standard generating polynomial for generating the frame check sequence is expressed by the following Equation (1).

The END field consists of one byte and represents the end of the frame. Like START Filed, it has a fixed value of 0x7F.

Figure 6 shows the size and description of each field.

C. Message Definition

The message definition defines the message type according to each code number, and defines command / data information and the length of the possible payload part for the corresponding message type. In addition, the values that each PAYLOAD part can take and their values provide meaning.

CODE Message Definition
[Message Name] Msg . type  [7: 6] ^# Pl . lng Explanation PAYLOAD ⁺ Param Description One Mode setting
[SetMode] 0 0 2+ (0-13) Base station operation mode setting command
- D-IDList is meaningful only when the power transmission mode is started: Applies only to devices that have '1' checked in the ID list of the device.
- The length of the IDList is incremented by the number of bytes according to the number of devices.
: Device 0 ~ 8 => 1 Byte
: Device 9 ~ 16 => 2 Bytes
: Device 104 ~ 112 => 14 Bytes [Mode]
[D-IDList] [Mode]
0x00: Stand By
0x01: Scan Start
0x02: Tracking Start
0x03: Transmit power - start individual mode
0x04: Power Transfer - Start Time Division Mode
0x05: Power transfer - start simultaneous mode
0x06: Power Transfer - Start Dual Mode
0x80: Stop working
[D-IDList]
0x01: Select ID = 1
0x02: Select ID = 2
0x03: ID = 1 & 2 selection
... .
0xFF: ID = 1 ~ 8 Select (Default) One 0 One Status report after operation mode setting [Result] 2 About Dev
[DevInform] 0 One One Requesting Dev information [D-ID] [D-ID]
0x00: All Devices
0x01: Device ID = 1
0x02: Device ID = 2
...
0x08: Device ID = 8
(Currently limited to 8) One One 9 Dev information response
(Unique Scan command and then upload Dev information) [D-ID] [ComMod] [Distance] [RSSI] [Freq] [Priority] [BattPer] [MaxPwrValue] [Used] 3 Communication modulation
[CommModul] 0 0 2 Communication modulation type setting command between BS and Dev [D-ID] [ComMod] [ComMod]
0x01: BPSK (Mandatory)
0x02: ASK
0x04: Load Modulation

[Result]
0x1x: Fail
0x11: Not Supported
0x12: CRC Error
0x14: TimeOut
0x01: Success
0x08: Waiting One 0 2 Report status after setting communication modulation method [D-ID] [Result] 0 One One Requesting a communication modulation scheme supported by Dev [D-ID] One One 2 Communication Modulation Response Supported by Dev [D-ID] [ComMod] 4 Effective distance of communication
[CommDist] 0 One 0 Request a distance (Semi-Charging Zone) from the base station according to [ComMod] - [Distance]
0 to 255 (centi meter) One One One Reporting distance supported by base station [Distance] 5 Transmission frequency
[TxFreq] 0 0 2 Power transmission frequency setting with Dev in power transmission mode [D-ID] [Freq] [Freq]
[7] = 0: Fixed Freq
[6: 0] = 0x01: LF1 (80 KHz)
[6: 0] = 0x02: LF2 (88 KHz)
[6: 0] = 0x04: LF3 (128 KHz)
[6: 0] = 0x08: MF1 (370 KHz)
[6: 0] = 0x10: MF2 (1.7 MHz)
[6: 0] = 0x20: HF1 (6.78 MHz)
[6: 0] = 0x40: HF2 (13.56 MHz)

[7] = 1: Step Freq
[6: 5] = 00,
[4: 0] = Start Freq (KHz)
[6: 5] = 01,
[4: 0] = Step (?)
[6: 5] = 11,
[4: 0] = Step Number One 0 2 Reporting configuration results [D-ID] [Result] 0 One One Power transmission frequency request supported by Dev [D-ID] One One 2 Power Supported in the Dev Frequency Response [D-ID] [Freq] 6 Output method
[TxCtrl] 0 0 One Set the base station's power signal output method in power transmission mode [Type] [Type]
0x00: Inverter type
0x001: Amp Type One 0 One Reporting configuration results [Result] 7 Output power
[TxPower] 0 0 2 Set the base station's output power to Dev in power transfer mode [D-ID] [PwrValue] [PwrValue]
? ~? (Watt)
[MaxPwrValue]
? ~? (Watt) One 0 One Reporting configuration results [Result] 0 One One Dev's request for maximum power to be received [D-ID] One 0 2 Maximum Power Acceptance Response from Dev [D-ID] [MaxPwrValue] 8 Active power transmission distance
[ChrgDist] 0 One 0 The base station requests power transmission distance (Charging Zone) according to the currently set transmission frequency [TxFreq], output method [TxCtrl], and output power [TxPower] - One One One Power transmission distance information [Distance] 9 device battery level
[DevBatt] 0 One One Ask Dev for current battery level info [D-ID] [BattPer]
0 to 100 (Percentage,%) One One 2 Dev's current battery level information [D-ID] [BattPer] 10 device priority
[DevPrio] 0 One One Requesting priority information from Dev [D-ID] [Priority]
1 to 255 (the smaller the priority is, the higher the priority) One One 2 Priority information for Dev [D-ID] [Priority] 11 Device Power Transmission Power
[DevChaPwr] 0 One One Requesting Power Transmission Signal Power Received at Dev [D-ID] One One 2 Information on the power transmission signal power received at Dev [D-ID] [PwrValue] 12 Device RSSI
[DevRSSI] 0 One One Requesting Dev's RSSI information [D-ID] One One 2 Dev's RSSI information [D-ID] [RSSI] [RSSI]
0 to 255 (dBm) 13 BS and device distance
[DistBSDev] 0 One One Request distance information between base station and device [D-ID] One One 2 Distance information between base station and device [D-ID] [Distance] 14 Device in action
[DevUsed] 0 One One Request information about whether Dev is currently running (for its intended purpose) [D-ID] [Used]
0: Not Used
1: Used One One 2 Information about the current behavior of Dev [D-ID] [Used] 15 Current power transfer device
[ActDevice] 0 One 0 Device ID request currently being transmitted - One One One Device ID currently being transmitted [D-ID] 16 Power transmission performance by frequency
[FreqChar] 0 One 0 Tracking result report request - One One 1 to X Power transmission performance information by frequency
(Refer to [Transmit frequency] parameter)
- Fixed Freq mode
: X = 7
: Reports the performance of LF1 to HF2 sequentially
- Step Freq mode
: X = (Step Number)
: Start frequency from start frequency [FChar-1]
..
[FChar-X] [FChar-X]
? (dbm? V? Load? ...) 17 error
[Error] One One 3 Error response to previous data request [Code] [Seq.Num ^] [Error] [Error]
0x1x: Error
0x11: Code is Not Supported
0x12: CRC Error
0x14: TimeOut
0x01: No Error 18 Foreign matter detection
[ObjDetect] One 0 One Notice of foreign substance detection result [Alarm] [Alarm]
0x00: Off
0x01: On

4. Wireless Power Transmission Control Interface Procedure

A. General Information

There are processes such as authentication, power transmission, and termination to provide wireless power transmission services to a plurality of power receivers. The procedures to be performed for wireless power transmission in the power transmission mode including simultaneous power transmission and time division power transmission and procedures to be performed in the differentiated charging zones and semi-charging zones, Procedures and procedures that must be followed in the event of an unexpected event during wireless power transmission.

B. Power receiver recognition / authentication, charging zone / semi-charging zone

The procedure of the power receiver recognition / authentication, charging zone / semi-charging zone is shown in Fig.

C. Simultaneous power transmission

The procedure of simultaneous power transmission is shown in FIG.

D. Time-sharing power transmission

The procedure of time division power transmission is shown in Fig.

E. Unexpected situation

1) Remove foreign matter

The procedure of foreign matter removal is shown in Fig.

2) The emergence of new power receivers and the disappearance of existing power receivers

The procedure for the emergence of a new power receiver and the disappearance of the existing power receiver is shown in Fig.

3) Buffering of existing power receiver

The procedure according to the buffering of the existing power receiver is shown in Fig.

F. Power transmission termination

The procedure of power transmission termination is shown in Fig.

G. Power transmission between devices

The procedure of power transmission between devices is shown in Fig.

5. Wireless Power Transmission H / W Interface

A. General Information

The physical elements of the wireless power transmission network consist of a power transmitter that performs device management and actual wireless power transmission in a magnetic field network and a power receiver that receives power and uses it as power transmission and power. The power receiver may be composed of one or more than one, depending on the system structure.

1) Wireless power transmission frequency

For the efficient wireless power transmission, the frequencies of low frequency (30 ~ 300kHz, LF) and medium frequency (300kHz ~ 30MHz (or 3MHz), MF) are used singly or simultaneously. The influence is designed to be less than -30dB.

2) Communication protocol

In order to efficiently transmit power to a plurality of electronic devices, time-division-based scheduling is performed. For efficient scheduling, a power transmitter exchanges device information from power receivers, and a power transmitter controls the joining, It requires a wireless communication protocol to manage the separation and release, and uses communication protocols such as In-band magnetic field communication, Bluetooth, and Zigbee.

3) Communication frequency

In case of using in-band magnetic field communication, low frequency (30 ~ 300kHz, LF) such as wireless power transmission is used for efficient use of radio resources. See Annex A for more detailed wireless communication protocols.

4) Antenna

An antenna for wireless power transmission uses a loop antenna that is relatively simple to implement at low frequencies and is easy to generate a magnetic field.

5) Dual band switching

According to the wireless power transmission environment and situation, it performs power transmission by switching the bands having high performance among the LF / MF dual bands.

B. Power Transmitter

1) Basic structure

The power transmitter includes an MF / LF antenna unit (primary coil) for wireless power transmission, a multi-matching unit for efficient wireless power transmission environment, an MF / LF power conversion unit for AC power generation, an LF magnetic field communication unit, And a system unit for interlocking with an upper system. Upon receipt of the required command from the system unit, the control unit of the power transmitter adjusts the MF / LF power transmission and communication units according to a time division manner to provide an efficient information delivery and power transmission environment to the power receivers in the wireless power transmission network.

The basic structure of the power transmitter is shown in Fig.

2) Input voltage and current

The voltage and current required for the power transmitter to operate are as follows.

- Voltage

- current

3) Voltage / current check

The components of the part for measuring the current flowing in the antenna for detecting the change on the wireless power transmission network and the voltage to be applied are as follows.

- Current sensor: Indicates the magnitude of the current flowing through the antenna as the magnitude of the voltage.

- Voltage sensor: Indicates the magnitude of the flowing voltage of the antenna.

4) Coupler (Multi-Matching Unit)

The impedance of the antenna is configured to be adjustable to Multi so that the antenna has optimal performance depending on the distance.

C. Power Receivers

1) Basic structure

The power receiver collects communication signals and wireless power from the power transmitter and collects communication information or drives an electronic device. The basic structure of the power receiver consists of an MF / LF antenna unit (secondary coil) for communication and power transmission, a matching circuit for power transfer efficiency, a regulator for receiving power processing, a rectifier and load, an LF magnetic field communication unit And a control unit for controlling it.

The basic structure of the power receiver is shown in Fig.

2) Input voltage and current

The voltage and current required for the power receiver to perform the wireless power transmission function are as follows.

- Voltage

- current

3) Overcurrent protection device

An overcurrent protection device is required that forcibly interrupts the wireless power transmission to protect the system if the current flowing due to the induced electromotive force in the device exceeds the limits of the devices constituting the device.

4) Receive power level according to application

The received power level (minimum value) from the power transmitter, which must be provided depending on the type of the target power receiver, is as follows.

- Mobile multimedia devices

- Portable tablet devices

- laptop

5) Shielding

The components for shielding the magnetic field of the wireless power transmission, which may interfere with the inherent functions of the power receiver, are as follows.

- Absorbent: Absorbing the magnetic field of the antenna and turning it back to the antenna greatly affects the performance of the antenna.

- Shielding: Shields the electric and magnetic fields that may affect the device.

6) Battery

The voltage and current required for power transmission in a battery are as follows. (The power is 1W or 0.5W.) The power limit is correct because the voltage / current condition of each battery is different, 4V if voltage is applied)

While the invention has been described in terms of the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention. Accordingly, the appended claims are intended to embrace all such modifications and variations as fall within the true spirit of the invention.

Claims (7)

A multi-node wireless power transmission system comprising a wireless power transmission device and a plurality of wireless charging devices spaced apart from the wireless power transmission device,
When the wireless charger is located in a semi-charging zone where communication is possible, the wireless power transmitter determines whether the wireless charger is the target of the wireless power transmission service based on the ID received from the wireless charging device,
Providing a wireless power transmission service to the wireless charging device when the wireless charging device is located in a charging zone capable of both communication and wireless power transmission,
The wireless power transmission service may be provided in a simultaneous power transmission mode or a time division power transmission mode, and the wireless power transmission service may be provided for all the wireless chargers in the simultaneous power transmission mode, for the wireless charger in the priority order in the time- The method includes sensing a voltage and current flowing through an antenna of the wireless power transmission apparatus as the wireless power transmission apparatus transmits test power, adjusting the resonance frequency based on the sensed voltage and current, And performs wireless power transmission to the wireless recharger. The method according to claim 1,
Wherein the superframe for the wireless power transmission service comprises a joining request superframe, a power request request superframe, and a power provision request superframe. 3. The method of claim 2,
Wherein the superframe for the wireless power transmission service includes a join request superframe, a power request request superframe, and a power provision request superframe,
The wireless power transmission service is started when the power transmission apparatus transmits a response request packet in a request interval of the merging request superframe, and the wireless recharging apparatus starts a response packet during a response period based on the information included in the response request packet. Lt; / RTI >
Wherein the response request packet includes information about wireless charging devices capable of transmitting a response packet during a response interval. The method of claim 1, wherein
When the wireless power transmission service is provided in the simultaneous power transfer mode, the wireless power transmission apparatus transmits a request for test power and reception power information to a plurality of wireless chargers, and when receiving the measured reception power, And adjusts the adjusted resonant frequency based on the calculated efficiency to perform a wireless power transmission to the wireless charger. The method according to claim 1,
As the wireless power transmission service is provided in the time division power transfer mode, the wireless power transmission apparatus transmits information of the priority of the wireless charging devices located in the charging zone to the wireless charging device,
The wireless power transmission apparatus calculates the efficiency for wireless power transmission when receiving the measured reception power by transmitting the request of the reception power information to the wireless recharger according to the priority order and outputs the adjusted resonance frequency to the calculated efficiency To perform wireless power transmission to the wireless recharger for a time allocated for each of the priorities. The method according to claim 1,
The wireless power transmission apparatus comprising: a wireless power transmission unit for sensing a change in voltage and current of an antenna of the wireless power transmission apparatus,
Wherein the unexpected situation includes at least one of an emergence situation of a foreign matter changing the efficiency of the wireless power transmission, an appearance state of a new wireless charging device, a disappearance state of the existing wireless charging device, and a buffering state of the existing wireless charging device, Wireless power transmission system. The method according to claim 1,
Wherein the wireless power transmission service uses at least one of a wireless power transmission band of 30 to 300 kHz and a wireless power transmission band of 300 to 30 MHz,
Wherein the influence of interference in each of the wireless power transmission bands is -30 dB or less.

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