KR20130032472A - Multi-device wireless power transmission system - Google Patents

Abstract

PURPOSE: A multi-device wireless power transmission system including an interface is provided to offer a procedure and a protocol of a control interface by defining a request of the interface for controlling wireless power transmission for multiple devices. CONSTITUTION: A multi-device wireless power transmission system includes a plurality of wireless charging devices separated from a wireless transmission device and a wireless power transmission device. The wireless charging device determines a target of a wireless power transmission service based on an ID(Identity) received from the wireless charging device while locating in a semi-charging zone. The wireless charging device provides the wireless power transmission service to the wireless charging device while locating in a charging zone. The wireless power transmission service is provided as a simultaneous power transmission mode or a time division power transmission mode. [Reference numerals] (AA) Charging base station; (BB) Charging device;

Description

Multi-device wireless power transmission system

The present invention relates to a multi-device wireless power transfer system, and more particularly to a multi-device wireless power transfer system having an interface for controlling wireless power transfer 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, 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, 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, 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 view of the above technical background, and an object of the present invention is to provide a multi-device wireless power transmission system having an interface for controlling wireless power transmission for a plurality of devices.

In order to solve this problem, the present invention defines the requirements of the interface for controlling the wireless power transmission for a plurality of devices, and provides the protocol and procedure of the control interface.

That is, the multi-device wireless power transfer system according to an aspect of the present invention is a multi-node wireless power transfer system including a wireless power transmitter and a plurality of wireless chargers spaced apart from the wireless power transmitter, wherein the wireless charger communicates. When the mobile terminal is located in a semi-charging zone, the wireless power transmitter determines whether the wireless charger is a wireless power transmission service based on an ID received from the wireless charger, and the wireless charger transmits both communication and wireless power transmission. When located in a possible charging zone, the wireless charger provides a wireless power transmission service, characterized in that the wireless power transmission service may be provided in a simultaneous power transmission mode or a time division power transmission mode.

According to the present invention, the requirements of an interface for controlling wireless power transfer for a plurality of devices are defined, and protocols and procedures of the control interface are provided to enable proper operation of the multi-device wireless power transfer system.

1 is a view showing an overview of 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 according to an embodiment of the present invention.
3 is a diagram illustrating physical / spatial components of a multi-device wireless power transmission system according to 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.
Msg. The contents of type are shown.
6 shows the size and description of each field.
7 is a procedure of power receiver recognition / authentication, charging zone / semicharging zone.
8 is a procedure of simultaneous power transmission.
9 is a procedure of time division power transmission.
10 is a procedure of removing foreign matter.
11 is a procedure according to the appearance of a new power receiver and the disappearance of an existing power receiver.
12 is a procedure according to the buffer of the existing power receiver.
13 is a procedure according to the end of power transmission.
14 is a procedure of power transmission between devices.
15 shows the basic structure of a power transmitter.
16 shows the basic structure of a power receiver.

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. 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 to a plurality of power receivers wirelessly 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 for managing a complicated wireless power transmission network is necessary compared to 1: 1 wireless power transmission. There are procedures and interfaces for the control and management of accidents such as the response to power receivers that suddenly disappear or appear after selecting the power transmission mode of each device based on the exchanged power transmission information, including ID recognition and authentication. It must be accompanied.

1 is a view showing an overview of 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. Wireless power transmission is performed by time division based scheduling, and the power transmitter manages the joining, separation, and release of the power receiver to control the wireless power transmission environment.

It provides power transmission function from several W to hundreds of W depending on the type of power receiver remotely including contact within a few meters within the near field, and guarantees efficiency of 70% or more for the required wireless power transmission distance for each product of the power receiver. Should be.

Low frequency (30 ~ 300kHz, LF) with relatively wide wireless power transmission bandwidth and medium frequency (300kHz ~ 30MHz, MF) band for relatively concentrated wireless power transmission for efficient wireless power transmission Are used alone or both, and the design of the antenna should be less than -30dB of interference between the two bands.

Networks using in-band magnetic field communication to exchange information and control signals among wireless power transmission networks use the same frequency as wireless power transmission in the LF magnetic field to increase the efficiency of frequency use.

Wireless power transmission network is divided into physical components, temporal components and spatial components. The physical component refers to a network consisting of a power transmitter and a power receiver, and the temporal component is composed of a superframe including a request section, a response section, and an inactive section. The spatial component is divided into a charging zone and a semi-charging zone. do.

The physical components of the wireless power transmission network are nodes including a power transmitter and a power receiver in a star topology network centered on the power transmitter. The wireless power transmission network is a network capable of data communication and wireless power transmission with each of the power receivers based on the 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 according to an embodiment of the present invention.

For effective management of power receivers, the basic preparation procedure for wireless power transmission should be preceded by recognizing and authenticating the power receivers in the area where communication is possible and exchanging data for wireless power transmission. Therefore, there is a virtual space divided into a charging zone and a semi-charging zone, and the power transmitter starts managing the power receivers in the semi-charging zone, which is a communicable area, of which the wireless zone is capable of transmitting wireless power. It performs the actual wireless power transmission to the power receivers belonging.

In the case of in-band magnetic field communication, spatial charging zone and semi-charging zone can be efficiently formed due to the characteristics of the magnetic field that cannot exist over a long distance.However, when using other communication methods, The number may surge and to prevent this, the power transmitter needs to adjust the output power of other communication methods.

The wireless power transmission network uses a time division multiple access (TDMA) scheme, which is managed by the power transmitter and distributed according to the request of the power receiver and the determination of the power transmitter.

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

A temporal element 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 that can transmit data in the response period, and the time slots are autonomously managed by the power receivers in the network of the selected group. The superframes of the wireless power transmission communication convergence network consist of three superframes as shown in Figure 4. An association request superframe, a power request request superframe, and a power preparation request superframe. The length of each request section and response section is variable. The superframe of the wireless power transmission network is started by the power transmitter transmitting a response request packet in the request section of the join request superframe. The response request packet has information on the power receivers that can transmit the 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

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

In order to provide wireless power transmission to a plurality of power receivers quickly, power receivers generally cannot be provided with a wireless power transmission service, but are required for power receiver recognition / authentication and wireless power transmission in a semi-charging zone capable of wireless communication. The basic data is exchanged to prepare for wireless power transmission. When the ready power receiver enters the charging zone, the wireless power transmission is performed to save the preparation time for wireless power transmission, thereby providing a quick service.

In order to efficiently provide wireless power transmission service, priority is given by time division based on simultaneous power transfer mode and battery remaining or user selection based on simultaneous power transfer mode to perform simultaneous wireless power transfer to all devices in charging zone according to the situation. There is a time division power transfer mode that performs power transfer.

When all the power receivers are fully charged, the power transmission can be terminated or the user can arbitrarily stop the current power transmission service.

There are many frequent and varied situations that must be considered for wireless power transfer to multiple power receivers. In order to effectively cope with this, if a sudden situation occurs on the network during wireless power transmission, the power transmitter recognizes this and stops the wireless power transmission service until the sudden situation is handled to notify the user of the unexpected situation.

B. Power Receiver Recognition / Certification

The power transmitter periodically transmits a communication signal in the entire superframe, and the power receivers receiving the signal transmit their IDs in response. The power transmitter determines whether the corresponding power receivers are the targets of the wireless power transmission service based on the received ID, and if the service transmitter is the service target, the power transmitter requests information for the wireless power transmission. Notify power receivers that are not subject to service and cannot provide service.

C. Charging Zone / Semi Charging Zone

The charging zone and the semi-charging zone are the spatial components of the wireless power transmission network. The only communication area is the semi-charging zone, and the communication zone and the wireless power transmission area are both charging zones. Provide service in semi-charging zone to provide wireless power transmission service to multiple power receivers efficiently and quickly.Recognize power receiver and exchange information necessary for power transmission. It is separated to proceed with the power transmission service.

D. Wireless Power Transfer Mode

1) Simultaneous power transfer mode

After the recognition of the power receiver and the exchange of information necessary for power transmission, the wireless power transmission service is started. Simultaneous power transmission mode during wireless power transmission is a mode for simultaneously transmitting wireless power to power receivers that need to provide all services in the charging zone. In order to improve the efficiency of wireless power transmission, the voltage / current flowing through the antenna is sensed and the resonant frequency is adjusted based on this, and the finer adjustment is performed by receiving the received power through communication and calculating the efficiency. After adjusting the resonant frequency, wireless power transmission is simultaneously performed to all power receivers, which continues until the end of wireless power transmission.

2) Time division power transfer mode

The wireless power transfer service starts after the recognition of the power receiver and the exchange of information necessary for wireless power transfer. The time division power transfer mode during wireless power transmission is a mode in which wireless power transmission is individually transmitted for each power receiver for a given time by dividing the allotted time by giving priority to power receivers that need to provide all services in the charging zone. . The wireless power transmission service is provided only for the time allotted for each power receiver, and is terminated when the service is completed for all power receivers.

E. Outbreaks

If a sudden situation occurs while the wireless power transmission service is in progress, the service provided will be stopped and the situation will be resolved. Incidents can be classified as foreign objects detection, the emergence of new power receivers, the disappearance of existing power receivers, and the exit due to the buffering of existing power receivers. All the accidents are sensed by sensing the change of voltage / current flowing through the antenna in the power transmitter and recognize the situation in detail through communication, and then take appropriate action.

1) Foreign object detection

If a foreign matter that changes the efficiency of wireless power transmission appears, it is recognized and the user is notified of the presence of the foreign matter in the form of an alarm.

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

If a new power receiver appears or if the existing power receiver disappears, it will find out the resonant frequency to maximize the efficiency of the wireless power transmission and resume the wireless power transmission service again.

3) Shock of the existing power receiver

When the power receiver currently receiving the wireless power transmission service is buffered, the service is blocked and the buffer is notified to the power transmitter through communication. After receiving the buffer information, the power transmitter resumes the wireless power transmission service to the remaining power receivers without considering the power receiver.

F. Termination of Wireless Power Transmission

The wireless power transfer termination is divided into a case in which there is no power receiver to provide a wireless power transfer service and a case in which the user wants to terminate. The wireless power transmission service currently being provided is terminated and the power transmitter enters the standby mode.

G. Power reception period wireless power transmission

If there is no power transmitter or the power receiver is not in the charging zone, the neighboring power receiver may request wireless power transmission. The received power receiver may transmit wireless power to the requested power receiver according to the user's choice.

3. Wireless Power Transfer Control Interface Protocol

A. General

It is information that needs to be exchanged in order to efficiently perform wireless power transmission. It defines data for controlling and managing wireless power transmission network between power transmitter and power receiver in the form of frame and defines the message actually transmitted.

B. Frame Format

1) frame structure

The frame including data for wireless power transmission control is composed of the elements shown in FIG. The power transmitter transmits control commands to the power receiver and the power receiver transmits power transmission information to the power transmitter through a frame composed as shown in the figure.

2) Field Description

The START field consists of 1 byte and indicates the start of one frame and has a fixed value of 0x7E.

CODE Field consists of 1 byte and is a code assigned to each message type to distinguish the message to be transmitted. See C. Message Definitions for details.

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)

Provides information on request / response and command / data for payload

bit # 7: 0 = REQ, 1 = RESP

bit # 6: 0 = CMD, 1 = DATA

Msg. The contents of type are shown.

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

Sequential numbers are assigned to each successive CODE frame to prevent lost frames when sending messages.

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

The length of the PAYLOAD following the control in bytes

PAYLOAD Field has variable length of 0 ~ 15 bytes and contains actual data. For details, see C. Message Definition.

The CRC Field consists of 1 byte and is used to determine whether the frame body has been received without error. The standard-generated polynomial that produces the frame check sequence is shown in Equation 1 below.

The END field consists of 1 byte and indicates the end of the frame. Like START Filed, it has a fixed value of 0x7F.

6 shows the size and description of each field.

C. Message Definition

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

CODE Message Definition
[Message people] Msg . type  [7: 6] ^# Pl . lng Explanation PAYLOAD ⁺ Param Description One Mode settings
[SetMode] 0 0 2+ (0 ~ 13) Command for setting operation mode of base station
-D-IDList is meaningful only when the power transfer mode starts: Applicable to the power transfer mode only for devices whose '1' is checked in the device's ID list.
-The length of IDList increases in byte unit according to the number of devices
: Device 0 ~ 8 => 1 Byte
: 9 ~ 16 devices => 2 Bytes
: 104 ~ 112 Devices => 14 Bytes [Mode]
[D-IDList] [Mode]
0x00: Stand By
0x01: Scan Start
0x02: Tracking Start
0x03: Start power transmission-individual mode
0x04: Start power transmission-time division mode
0x05: Start power transmission-simultaneous mode
0x06: Start power transmission-dual mode
0x80: Stop working
[D-IDList]
0x01: select ID = 1
0x02: ID = 2 selection
0x03: ID = 1 & 2 selected
... .
0xFF: ID = 1 ~ 8 selection (Default) One 0 One Status report after setting operation mode [Result] 2 Dev information
[DevInform] 0 One One Request 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
(Independently upload Dev information after Scan command) [D-ID] [ComMod] [Distance] [RSSI] [Freq] [Priority] [BattPer] [MaxPwrValue] [Used] 3 Communication modulation
[CommModul] 0 0 2 Command to set communication modulation method 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 Status report after setting communication modulation method [D-ID] [Result] 0 One One Communication Modulation Requests Supported by Dev [D-ID] One One 2 Communication Modulation Responses Supported by Dev [D-ID] [ComMod] 4 Communication effective distance
[CommDist] 0 One 0 Semi-Charging Zone request for communication support from base station according to [ComMod] - [Distance]
0 to 255 (centi meter) One One One Report distances that support communication from the base station [Distance] 5 Transmit frequency
[TxFreq] 0 0 2 Set power transmission frequency with Dev in power transfer 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 Report setup results [D-ID] [Result] 0 One One Power Transfer Frequency Requests Supported by Dev [D-ID] One One 2 Power Transfer Frequency Response Supported by Dev [D-ID] [Freq] 6 Output method
[TxCtrl] 0 0 One Set power signal output method of base station in power transfer mode [Type] [Type]
0x00: Inverter type
0x001: Amp Type One 0 One Report setup results [Result] 7 Output power
[TxPower] 0 0 2 Base station output power setting for Dev in power transfer mode [D-ID] [PwrValue] [PwrValue]
? ~? (Watt)
[MaxPwrValue]
? ~? (Watt) One 0 One Report setup results [Result] 0 One One Dev's Maximum Received Power Intensity Request [D-ID] One 0 2 Maximum receivable power strength response in Dev [D-ID] [MaxPwrValue] 8 Effective power transmission distance
[ChrgDist] 0 One 0 Charging Zone Request based on 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 Request current battery level information from Dev [D-ID] [BattPer]
0-100 (Percentage,%) One One 2 Dev's current battery level information [D-ID] [BattPer] 10 device priority
[DevPrio] 0 One One Requesting Dev's Priority Information [D-ID] [Priority]
1 to 255 (the smaller the higher the priority) One One 2 Dev priority information [D-ID] [Priority] 11 Device Power Transfer Power
[DevChaPwr] 0 One One Power request signal power request received by Dev [D-ID] One One 2 Power Transmission Signal Power Information Received by Dev [D-ID] [PwrValue] 12 Device RSSI
[DevRSSI] 0 One One Request RSSI information from Dev [D-ID] One One 2 Dev's RSSI information [D-ID] [RSSI] [RSSI]
0 ~ 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 operation
[DevUsed] 0 One One Request information whether Dev is currently working (for its original purpose) [D-ID] [Used]
0: Not Used
1: Used One One 2 Information about Dev 's current operation [D-ID] [Used] 15 Current power transmission device
[ActDevice] 0 One 0 Device ID request currently being transmitted - One One One Device ID currently being transmitted [D-ID] 16 Frequency-specific power transfer performance
[FreqChar] 0 One 0 Request tracking result report - One One 1 to X Frequency Transmission Performance Information
(See [TX Frequency] parameter.)
Fixed Freq Mode
: X = 7
: Report on the performance of LF1 ~ HF2 sequentially
Step Freq Mode
: X = (Step Number)
: Report sequentially from Start Frequency [FChar-1]
..
[FChar-X] [FChar-X]
? (dbm? V? Load?…) 17 error
[Error] One One 3 Response error information for previous data requests [Code] [Seq.Num ^] [Error] [Error]
0x1x: Error
0x11: Code is Not Supported
0x12: CRC Error
0x14: TimeOut
0x01: No Error 18 Foreign object detection
[ObjDetect] One 0 One Foreign object detection result notification [Alarm] [Alarm]
0x00: Off
0x01: On

4. Wireless Power Transfer Control Interface Procedure

A. General

There are processes such as authentication, power transmission, and termination for providing wireless power transmission services to a plurality of power receivers. Procedures for terminating power transfer and procedures performed for wireless power transfer in power transfer modes, including simultaneous power transfer and time division power transfer, as well as procedures to recognize and authenticate power receivers and to be performed in separate charging and semi-charging zones. Includes procedures and procedures that should be followed when an accident occurs during wireless power transfer.

B. Power Receiver Recognition / Certification, Charging Zone / Semi Charging Zone

The procedure of power receiver recognition / authentication, charging zone / semicharging zone is shown in FIG.

C. Simultaneous Power Transmission

The procedure of simultaneous power transfer is shown in FIG.

D. Time Division Power Transmission

The procedure of time division power transfer is shown in FIG.

E. Outbreaks

1) Remove foreign substances

The procedure of debris removal is shown in FIG.

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

The procedure of the appearance of the new power receiver and the disappearance of the existing power receiver is shown in FIG.

3) Shock of the 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 transfer between devices

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

5. Wireless power transmission H / W interface

A. General

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

1) Wireless power transmission frequency

For efficient wireless power transmission, low frequency (Low frequency, 30 ~ 300kHz, LF) and Medium frequency (Medium frequency, 300kHz ~ 30MHz (or 3MHz), MF) bands are used alone or simultaneously. Design the effect to be below -30dB.

2) communication protocol

In order to efficiently transmit power to a plurality of electronic devices, time-sharing-based scheduling is performed. For efficient scheduling, the power transmitter exchanges device information from the power receivers, and the power transmitter combines the power receivers to control the wireless power transmission environment. Wireless communication protocol is required to manage separation and release, and communication protocols such as in-band magnetic field communication, Bluetooth, and Zigbee are used.

3) communication frequency

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

4) antenna

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

5) Dual Band Switching

According to the wireless power transmission environment and situation, power transmission is performed by switching the band with the best performance among the LF / MF dual bands.

B. Power Transmitter

1) Basic structure

The power transmitter is an MF / LF antenna unit (primary coil) for wireless power transmission, multi-matching unit for efficient wireless power transmission environment, MF / LF power conversion unit for AC power generation, LF magnetic field communication unit, environmental control Consists of a control unit and a system unit for interworking with the host system. Upon receiving the necessary commands 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 scheme, thereby providing an efficient information transmission and power transmission environment for 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 to operate the power transmitter are as follows.

- Voltage

Current

3) Voltage / Current Check

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

-Current sensor: Displays the current flowing through the antenna as the voltage.

Voltage sensor: indicates the magnitude of the voltage flowing through the antenna.

4) Coupler (Multi-Matching Unit)

The antenna's impedance can be adjusted to Multi for optimal performance.

C. Power Receiver

1) Basic structure

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

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

2) input voltage and current

The followings are the voltage and current required for the power receiver to perform the wireless power transfer function.

- Voltage

Current

3) Overcurrent protection device

When the current flowing from the electromotive force induced in the device exceeds the limit of the elements constituting the device, an overcurrent protection device forcibly interrupting wireless power transmission is required to protect the system.

4) Receive power level according to application

The received power level (minimum value) from the power transmitter that must be provided according to the type of power receiver to be targeted is as follows.

-Mobile multimedia devices

-Portable tablet devices

- laptop

5) shielding

The components for shielding the magnetic field of the wireless power transmission that may hinder the inherent function of the power receiver are as follows.

-Absorber: Absorb the antenna's magnetic field and return it back to the antenna, which greatly affects the performance of the antenna.

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

6) battery

The voltage and current requirements for power transfer in the battery are as follows. (The power is 1W or 0.5W. It seems that the power limit is correct because the voltage / current conditions are different for each battery. If the voltage is 4V)

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 will include such modifications and variations as long as they fall within the spirit of the invention.

Claims (1)

A multi-node wireless power transfer system including a wireless power transmitter and a plurality of wireless chargers spaced apart from the wireless power transmitter,
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,
Wherein the wireless power transmission service can be provided in a simultaneous power transmission mode or a time sharing power transmission mode.

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