KR20220105002A - Apparatus and method for transmitting power wirelessly - Google Patents

Abstract

The present invention relates to an apparatus for wirelessly transmitting power. In accordance with one embodiment of the present invention, the apparatus for wirelessly transmitting power comprises: at least two primary coils including first and second coils placed apart from each other to transmit power to a secondary coil of a reception device; an inverter converting DC power into AC power to supply the power to the at least two primary coils while provided in accordance with the number of the at least two primary coils; and a coil moving part for moving at least the first coil of the at least two primary coils, wherein the coil moving part can move the first coil from a first position to a second position in which the second coil is located, to overlap the first and second coils on the second position. The apparatus for wirelessly transmitting power can also include a switch part for controlling the connection of the at least two primary coils and the inverter. The switch part can serially connect the first and second coils when the first coil is located on the second coil, and can connect the serially connected first and second coils to one single inverter. Therefore, the present invention is capable of increasing charging efficiency by shortening a distance between the first and second coils.

Description

Wireless power transmission apparatus and method {Apparatus and method for transmitting power wirelessly}

This specification relates to an apparatus and method for wirelessly transmitting power, and more particularly, to an apparatus for changing the position of a transmitting coil so that two or more transmitting coils are unfolded or overlapped.

With the development of communication and information processing technology, the use of smart devices for smart phones is gradually increasing. The charging method currently widely applied to smart devices is to supply external power by directly connecting an adapter connected to a power source to the smart device. It is a method of charging by receiving and charging, or by connecting to a smart device through the USB terminal of the host and receiving USB power from the host.

Recently, in order to reduce the inconvenience of having to directly connect a smart device to an adapter or a host through a connection line, a wireless charging method of wirelessly charging a battery using magnetic coupling without electrical contact is gradually applied to smart devices. .

In addition, the use of smart watches and smart earphones as peripheral devices of smart phones is increasing explosively, and wireless charging functions are introduced to these peripheral devices like smart phones, so that they can be conveniently charged.

Since modern people carry smart devices such as smart phones, smart watches, and smart earphones on their body every day, it is advantageous to employ a plurality of transmitting coils in one wireless charger so that they can be charged at the same time, and it is composed of a plurality of coils. A wireless charger employing a multi-coil that can be used is also on the market.

On the other hand, in the case of a currently commercialized wireless charger, only low power of 15W or less can be charged and the transmission distance is short. For wireless charging, a smart device, which is a power receiving device, must be brought into contact with a wireless charger, which is a power transmitting device, for wireless charging. As described above, there is a problem in that the power transmission capability is low and the transmission distance is short in the conventional power transmission device.

Although a standard specification has not yet been established, the need for developing a wireless charger capable of wirelessly charging electronic devices that require a large operating current and employ a large-capacity battery, such as a tablet or laptop, is also increasing.

This specification is in view of this situation, and an object of this specification is to provide a transmission coil capable of simultaneously wirelessly charging a plurality of electronic devices and wirelessly transmitting high-capacity power.

Another object of the present specification is to provide a wireless charger capable of simultaneously wirelessly charging a plurality of electronic devices and wirelessly charging an electronic device employing a high-capacity battery.

A wireless power transmission device according to an embodiment of this specification for realizing the above object, including a first coil and a second coil that are spaced apart, for transmitting power to the secondary coil of the receiving device, two more than one primary coil; an inverter that converts direct current power into alternating current and supplies it to two or more primary coils, including a number corresponding to the number of two or more primary coils; and a coil moving unit for moving at least a first coil among the two or more primary coils, wherein the coil moving unit moves the first coil from the first position to a second position where the second coil is located to move the first coil from the second position. It is characterized in that the coil and the second coil are overlapped.

Wireless power transmission method according to another embodiment of this specification, when the electronic device is placed in a first position, wirelessly transmitting power to the electronic device through a first coil; when there is no electronic device in the first position and the electric device is placed in the second position, moving the first coil to the second position to overlap the second coil; and wirelessly transmitting power to the electronic device placed at the second position through the first coil and the second coil.

A single wireless charger can not only wirelessly charge several electronic devices at the same time, but also wirelessly charge electronic devices that require high-capacity power.

In addition, power transmission efficiency can be maintained similar to each other when wirelessly charging multiple electronic devices at the same time, and when charging electronic devices employing high-capacity batteries, the charging efficiency can be increased by making the distance between the primary coil and the secondary coil closer. there will be

1 is a conceptual diagram illustrating that power is wirelessly transmitted from a wireless power transmission device to an electronic device;
2 is a schematic diagram of a circuit configuration of a power converter of a transmission module for wirelessly transmitting power in an electromagnetic induction method;
3 is a diagram illustrating a configuration for a wireless power transmission module and a reception module to exchange power and a message;
4 is a block diagram illustrating a loop for controlling power transmission between a wireless power transmission module and a reception module,
Figure 5 shows a plan view from above of a multi-coil employed in a wireless charger according to this specification,
6 is a side view of a multi-coil employed in a wireless charger according to this specification, viewed from the side;
7 shows a process of overlapping by moving some coils constituting a multi-coil for high-capacity output according to this specification;
Figure 8 shows the connection with the inverter when individually driving each transmission coil constituting the multi-coil according to an embodiment of this specification,
9 is a diagram illustrating a connection with an inverter when driving by overlapping transmission coils constituting a multi-coil according to another embodiment of the present specification and connected in series;
10 is a functional block showing the configuration of a wireless power transmission module for moving the primary coil constituting the multi-coil according to this specification,
11 is an operation flowchart for a method of wirelessly charging a plurality of electronic devices simultaneously through a multi-coil or wirelessly charging a large-capacity electronic device by overlapping multi-coils according to this specification;
12 shows an exploded perspective view of a charger according to this specification.

Hereinafter, an embodiment of a wireless power transmission apparatus and method according to this specification will be described in detail based on the accompanying drawings.

1 is a conceptual diagram illustrating wireless power transmission from a wireless power transmission device to an electronic device.

The wireless power transmission device 1 may be a power transmission device for wirelessly transmitting power required by the electronic device 2 or a wireless charging device for charging a battery of the electronic device 2 by wirelessly transmitting power. Alternatively, it may be implemented as various types of devices that deliver power to the electronic device 2 requiring power in a non-contact state.

The electronic device 2 is a device capable of wirelessly receiving power from the wireless power transmitter 1 to operate, and may charge a battery using the wirelessly received power. Electronic devices that receive power wirelessly include portable electronic devices, such as smart phones, smart terminals, tablet computers, multimedia terminals, keyboards, mice, input/output devices such as video or audio auxiliary devices, and auxiliary batteries. can do.

Resonance occurs in the electronic device 2 by the inductive coupling method based on the electromagnetic induction phenomenon by the wireless power signal of the wireless power transmitter 1, that is, the wireless power signal transmitted from the wireless power transmitter 1, and the resonance phenomenon Power can be transferred wirelessly without contact from the wireless power transmitter 1 to the electronic device 2 by the electromagnetic induction phenomenon. It transmits power by induction.

When the intensity of the current flowing in the primary coil of the wireless power transmitter 1 changes, the magnetic field passing through the primary coil or transmission coil (primary coil, TX coil) is changed by the current, and the changed magnetic field is the electronic device (2) An induced electromotive force is generated on the side of the secondary coil or the receiving coil (RX coil).

The wireless power transmitter 1 and the electronic device 2 are arranged so that the primary coil of the wireless power transmitter 1 and the secondary coil of the electronic device 2 are close to each other, and the wireless power transmitter 1 When α controls the current of the primary coil to change, the electronic device 2 supplies power to a load such as a battery by using the electromotive force induced in the secondary coil.

Since the efficiency of wireless power transfer by the inductive coupling method is affected by the arrangement and distance between the wireless power transmitter 1 and the electronic device 2, the wireless power transmitter 1 is configured to include a flat interface surface. and a primary coil mounted on a lower portion of the interface surface, and one or more electronic devices may be placed on the interface surface. By making the space between the primary coil mounted below the interface surface and the secondary coil located above the interface surface sufficiently small, the efficiency of wireless power transfer by inductive coupling can be increased.

A mark indicating a position where the electronic device is to be placed may be displayed on the upper portion of the interface surface, and may indicate the position of the electronic device so that the arrangement between the primary coil and the secondary coil mounted under the interface surface is properly made. . A protruding structure for guiding the position of the electronic device may be formed on the interface surface, and a magnetic material such as a magnet is formed under the interface surface to form a primary coil by attraction with a magnetic material of another pole provided inside the electronic device. You can also guide the and secondary coils to be well aligned.

2 is a conceptual diagram illustrating a circuit configuration of a power converter of a transmission module for wirelessly transmitting power in an electromagnetic induction method.

The wireless power transmission module may be largely configured to include a power source and a power conversion unit composed of an inverter and a resonance circuit, the power source may be a voltage source or a current source, and the power conversion unit converts the power supplied from the power source into a wireless power signal to wirelessly It is transmitted to the power receiving module. The wireless power signal is formed in the form of a magnetic or electromagnetic field having resonance characteristics, and the resonance circuit includes a coil for generating a wireless power signal.

The inverter converts a DC input into an AC waveform of a desired voltage and frequency through a switching element and a control circuit. FIG. 2 shows a full-bridge inverter, and other types of inverters such as a half-bridge inverter are also possible. .

The resonant circuit is configured to include a primary coil (Lp) and a capacitor (Cp) to transmit power in a magnetic induction manner, and the coil and capacitor determine a fundamental resonant frequency of power transmission. The primary coil forms a magnetic field corresponding to a wireless power signal according to a change in current, and may be implemented in the form of a flat plate or a solenoid.

The alternating current converted by the inverter drives the resonance circuit, thereby creating a magnetic field in the primary coil. By controlling the on/off timing of the switch that includes the inverter, it generates an alternating current with a frequency close to the resonance frequency of the resonance circuit and transmits the module. The transmission efficiency of the transmission module can be increased, and the transmission efficiency of the transmission module can be changed by controlling the inverter.

3 illustrates a configuration for a wireless power transmission module and a reception module to exchange power and a message.

Since the power converter only transmits power unilaterally regardless of the reception state of the reception module, in order to transmit power to match the state of the reception module, a configuration for receiving feedback related to the reception state from the reception module is required for the wireless power transmission module do.

The wireless power transmission module 100 may be configured to include a power conversion unit 110 , a communication unit 120 , a control unit 130 , and a power supply unit 140 , and the wireless power reception module 200 is a power receiving unit 210 . , it may be configured to include the communication unit 220 and the control unit 230 and may be configured to further include a load (or power supply unit) 240 to which the received power is supplied. The load 240 may include a charging unit for charging the internal battery with power supplied from the power receiving unit 210 .

The power converter 110 may be configured to include an inverter and a resonance circuit of FIG. 2 , and further include a circuit capable of adjusting characteristics such as a frequency, voltage, and current used to form a wireless power signal.

The communication unit 120 is connected to the power conversion unit 110 and demodulates a wireless power signal modulated by the reception module 200 that wirelessly receives power according to magnetic induction from the transmission module 100 to receive a power control message. can be detected.

The control unit 130, based on the message detected by the communication unit 120, determines one or more characteristics of the operating frequency, voltage, and current of the power conversion unit 110, and controls the power conversion unit 110 to convert power It may cause the unit 110 to generate a wireless power signal suitable for the message. The communication unit 120 and the control unit 130 may be configured as one module.

The power receiver 210 includes a matching circuit comprising a secondary coil and a capacitor in which an induced electromotive force is generated according to a change in a magnetic field generated in the primary coil of the power converter 110, and an alternating current flowing through the secondary coil It may include a rectifier circuit that rectifies the current to output a direct current.

The communication unit 220 of the receiving module is connected to the power receiving unit 210, and by adjusting the load of the power receiving unit in a manner that adjusts a resistive load in DC and/or a capacitive load in AC, the transmitting module and the receiving module It is possible to transmit a power control message to the transmission module by changing the wireless power signal between them.

The control unit 230 of the reception module controls each component included in the reception module, measures the output of the power reception unit 210 in the form of current or voltage, and controls the communication unit 220 based on this to wirelessly transmit power A power control message may be transmitted to the module 100 . The message may instruct the wireless power transmission module 100 to start or end the transmission of the wireless power signal, and may also adjust the characteristics of the wireless power signal.

The wireless power signal formed by the power converting unit 110 of the transmission module is received by the power receiving unit 210, and the control unit 230 of the receiving module controls the communication unit 220 to modulate the wireless power signal, the control unit ( The 230 may perform a modulation process to change the amount of power received from the wireless power signal by changing the reactance of the communication unit 220 . When the amount of power received from the wireless power signal changes, the current and/or voltage of the power conversion unit 110 that forms the wireless power signal also changes, and the communication unit 120 of the wireless power transmission module 100 is the power conversion unit 110 . A demodulation process may be performed by sensing a change in current and/or voltage.

The control unit 230 of the receiving module generates a packet including a message to be transmitted to the wireless power transmission module 100 and modulates the wireless power signal to include the generated packet, and the control unit 130 of the transmission module is a communication unit The packet extracted through 120 may be decoded to obtain a power control message, and the control unit 230 of the receiving module is a wireless power signal based on the amount of power received through the power receiving unit 210 in order to adjust the received power. You can send a message requesting to change the properties of

4 is a block diagram illustrating a loop for controlling power transmission between a wireless power transmission module and a reception module.

A current is induced in the power receiver 210 of the receiving module 200 according to a change in the magnetic field generated by the power converter 110 of the transmitting module 100 to transmit power, and the controller 230 of the receiving module A control point, that is, a desired output current and/or voltage is selected, and an actual control point of power received through the power receiver 210 is determined.

The control unit 230 of the receiving module 100 calculates a control error value using a desired control point and an actual control point while power is being transmitted, for example, to take the difference between two output voltages or currents as a control error value. can The control error value can be determined so that if less power is required to reach the desired control point, for example, it will be a negative value, and if more power is needed to reach the desired control point, it will be a positive value. The control unit 230 of the reception module 200 generates a packet including a control error value calculated in a manner that changes the reactance of the power reception unit 210 according to time through the communication unit 220 to the transmission module 100 . can be transmitted

The communication unit 120 of the transmission module detects a message by demodulating a packet included in the wireless power signal modulated by the reception module 200, and may demodulate a control error packet including a control error value.

The control unit 130 of the transmission module decodes the control error packet extracted through the communication unit 120 to obtain a control error value, and the receiving module uses the actual current value and the control error value that actually flow through the power conversion unit 110 . A new current value for transmitting the desired power can be determined.

When the system is stabilized from the process of receiving the control error packet from the receiving module, the control unit 130 of the transmission module is applied to a new operating point, that is, the primary coil so that the actual current value flowing through the primary coil becomes a new current value. The power converter 110 is controlled so that the magnitude, frequency, duty ratio, etc. of the AC voltage reach a new value, and a new operating point is continuously maintained so that the receiving module can additionally communicate control information or status information.

The interaction between the wireless power transfer module 100 and the wireless power reception module 200 includes four steps, including selection, ping, identification & configuration, and power transfer. can be made with The selecting step is a step for the transmitting module to discover an object placed on the interface surface, the ping step is a step to check whether the object includes a receiving module, and the identifying/configuring step is a preparation step for sending power to the receiving module to receive appropriate information from the receiving module and conclude a power transfer contract with the receiving module based on this is a step

In the ping step, the receiving module 200 transmits a signal strength packet (Signal Strength Packet, SSP) indicating the magnetic flux coupling degree of the primary coil and the receiving coil to the transmission module 100 through modulation of the resonance waveform, the signal strength The packet SSP is a message generated by monitoring the voltage rectified by the reception module, and the transmission module 100 may receive it from the reception module 200 and use it to select an initial driving frequency for power transmission.

In the identification/configuration step, an identification packet including the version of the reception module 200, a manufacturer code, device identification information, etc., the maximum power of the reception module 200, a configuration including information such as a power transmission method The receiving module 200 transmits a packet (Configuration Packet) and the like to the transmitting module 100 .

In the power transmission step, a control error packet (Control Error Packet, CEP) indicating the difference between the operating point at which the receiving module 200 receives the power signal and the operating point determined in the power transmission contract, the receiving module 200 is connected to the interface surface The receiving module 200 transmits a received power packet (RPP) indicating the average value of the power received through .

The reception power packet (RPP) is received power amount data in consideration of the rectified voltage, load current, offset power, etc. of the power reception unit 210 of the reception module, and continues to receive power by the reception module 200 while the transmission module 100 ), and the transmission module 100 receives it and uses it as an operation factor for power control.

The communication unit 120 of the transmission module extracts a packet from the change in the resonance waveform, respectively, and the control unit 130 decodes the extracted packet to obtain a message and controls the power conversion unit 110 based on this to obtain the receiving module 200 Power can be transmitted wirelessly while changing the power transmission characteristics as requested.

On the other hand, in the method of wirelessly transmitting power by inductive coupling, the efficiency has little effect depending on the frequency characteristic, but is affected by the arrangement and distance between the transmission module 100 and the reception module 200 .

The area where the wireless power signal can reach can be divided into two types, and when the transmission module 100 wirelessly transmits power to the reception module 200, a high-efficiency magnetic field passes through the portion of the interface surface. It may be called an area, and the area in which the transmission module 100 can detect the presence of the reception module 200 may be referred to as a sensing area.

The control unit 130 of the transmission module may detect whether the reception module 200 is disposed or removed in the active area or the detection area, using a wireless power signal formed in the power conversion unit 110 or provided separately. Whether the receiving module 200 is disposed in the active area or the sensing area may be detected by the sensor.

For example, the control unit 130 of the transmission module is affected by the wireless power signal due to the reception module 200 existing in the sensing area, and the power characteristic for forming the wireless power signal of the power converter 110 is changed. It is possible to detect the presence of the receiving module 200 by monitoring whether or not. The control unit 130 of the transmission module may perform a process of identifying the reception module 200 or determine whether to start wireless power transmission or the like according to a result of detecting the presence of the reception module 200 .

The power conversion unit 110 of the transmission module may further include a position determination unit, and the position determination unit may move or rotate the primary coil in order to increase the efficiency of wireless power transfer by inductive coupling, in particular, the receiving module ( 200) may be used when it does not exist in the active area of the transmission module 100 .

The positioning unit moves the primary coil so that the distance between the centers of the primary coil of the transmitting module 100 and the secondary coil of the receiving module 200 is within a certain range, or so that the centers of the primary coil and the receiving coil overlap. It may be configured to include a driving unit for moving the primary coil. To this end, the transmission module 100 may further include a sensor or a detection unit for detecting the position of the reception module 200 , and the control unit 130 of the transmission module receives the reception module 200 from the sensor of the detection unit. The positioning unit may be controlled based on the location information.

Alternatively, the control unit 130 of the transmission module may receive control information on the arrangement or distance with the reception module 200 through the communication unit 120 and control the position determination unit based on the control information.

In addition, the transmission module 100 is formed to include two or more of a plurality of primary coils to selectively use some of the coils that are suitably arranged with the receiving coil of the receiving module 200 among the plurality of primary coils to increase the transmission efficiency. In this case, the positioning unit may determine which one of the plurality of primary coils will be used for power transmission.

A single primary coil or a combination of one or more primary coils that form a magnetic field passing through the active region may be referred to as a primary cell. to detect and determine the active area based on this, connect the transmission module constituting the main cell corresponding to the active area, and inductively couple the primary coil of the transmission module and the secondary coil of the receiving module 200 can be controlled

On the other hand, the receiving module 200 is embedded in an electronic device such as a smart phone or a smart device including a smart phone or a multimedia playback terminal, and the electronic device is not constant in a vertical or horizontal direction on the interface surface of the transmission module 100 Depending on the orientation or position, the transmission module requires a large active area.

When a plurality of primary coils are used to expand the active area, a driving circuit is required as many as the number of primary coils and the control of the plurality of primary coils becomes complicated, so the cost of the transmission module, that is, the wireless charger increases when commercialized. . In addition, even when the method of changing the position of the transmission coil is applied to expand the active area, since a transport mechanism for moving the position of the primary coil must be provided, there is a problem in that the volume and weight increase and the manufacturing cost increases.

It is effective if there is a method of expanding the active area even with one primary coil having a fixed position, but if the size of the primary coil is simply increased, the magnetic flux density per unit area of the primary coil decreases and the magnetic coupling force between the transmitting and receiving coils decreases. It is weakened, so that the active area does not increase as expected and the transmission efficiency decreases.

As such, it is important to determine an appropriate shape and size of the primary coil to expand the active area and improve transmission efficiency. A multi-coil method employing two or more primary coils is effective as a method of expanding the active area of the wireless power transmission module.

In this specification, two or more primary coils constituting a multi-coil may be arranged side by side on the interface of the transmission module at a predetermined interval to expand the active area of the wireless power transmission module and wirelessly charge a plurality of electronic devices at the same time.

In addition, in this specification, in order to wirelessly charge an electronic device having a large operating current, such as a tablet or a laptop, some of two or more primary coils arranged side by side may be moved to overlap the primary coils.

In order to superimpose two or more primary coils constituting a multi-coil with each other, a device for moving the primary coil, for example, a rail, a moving shaft, and a moving means are provided, and a moving shaft attached to the primary coil to be moved is attached to the rail. coupled and the moving means may move the axis of movement along the rail.

When two or more primary coils constituting a multi-coil charge an electronic device, each primary coil is connected to a different inverter and operates individually When charging with , two or more overlapping primary coils can be connected in series and operated through one inverter. To this end, a switch unit for controlling the connection between each primary coil and a corresponding inverter may be provided.

In addition, when two or more primary coils constituting a multi-coil constitute an independent transmission module together with a corresponding inverter and operate individually, in order to keep the transmission efficiency of each transmission module constant, the interface surface at each primary coil distance can be kept constant. That is, when the primary coils are spread out in terms of a plane viewed from above the interface, each primary coil may be disposed at the same height in terms of the side.

In order to overlap by moving some of the two or more primary coils disposed at the same height, the position of the primary coils to be moved to a position where the rail guiding the movement of the primary coil on a side basis will overlap may be raised or lowered. .

Figure 5 shows a top view of the multi-coil employed in the wireless charger according to this specification, Figure 6 shows a side view of the multi-coil employed in the wireless charger according to this specification from the side, Figure 7 is According to this specification, it shows a process of overlapping by moving some coils constituting the multi-coil for high-capacity output.

5 to 7, the multi-coil 115 constituting the transmission coil of the wireless power transmission device is illustrated as being composed of three primary coils 115_1, 115_2, 115_3, but this specification is not limited thereto. The multi-coil may be composed of two or four or more primary coils.

In addition, in FIGS. 5 and 6 , the three primary coils 115_1 , 115_2 , 115_3 are arranged side by side in a direction centered on the second primary coil 115_2 in the middle (the second primary coil 115_2 ) Although the first and third primary coils 115_1 and 115_3 are arranged at a 180 degree angle to the center, this specification is not limited thereto. The first and third primary coils 115_1 and 115_3 may be arranged in a 90-degree bent shape around the second primary coil 115_2, and the bent angle is different from 90 degrees, for example 120 degrees or 60 degrees. it might be the way This angle may vary depending on how the transmission device will plan the shape of the interface on which the electronic device is to be placed.

A rail 119 to guide the movement of the first and third primary coils 115_1 and 115_3 may be disposed around the three primary coils. A ferrite sheet may be disposed under the primary coil.

In a state in which the three primary coils are spread out, the first to third primary coils 115_1 , 115_2 , and 115_3 are disposed at the same height on the ferrite sheet. In a state in which the first to third primary coils 115_1 , 115_2 , and 115_3 overlap each other, the first and third primary coils 115_1 and 115_3 may be disposed on the second primary coil 115_2 .

This specification is not limited thereto, but the first and third primary coils 115_1 and 115_3 may be disposed below the second primary coil 115_2, and the first and third primary coils 115_1 and 115_3 ) may be disposed above the second primary coil 115_2 and the other may be disposed below the second primary coil 115_2. When the first and third primary coils 115_1 and 115_3 move over the second primary coil 115_2 , the second primary coil 115_2 may be fixed or adhered to the ferrite sheet.

6 and 7 , the first and third primary coils 115_1 and 115_3 sequentially move along the first and second rails 119_1 and 119_2 to the second primary coil 115_2. can be overlapped with A moving axis attached to the first and third primary coils 115_1 and 115_3 is coupled to the first and second rails 119_1 and 119_2, and a predetermined moving means moves the moving axis to move the first and second rails. 3 The primary coils 115_1 and 115_3 may be spread apart from the second primary coil 115_2 , or may overlap the second primary coil 115_2 .

The rails 119_1 and 119_2 are coupled to the axis of movement of the first coil to be moved, and the first portion having a constant height (first height) placed in the first position where the moving first coil is unfolded, the first coil is different A second portion having a constant height (second height) (first height and second height different from each other) lying in a second position overlapping the first coil, and a third portion inclined between the first position and the second position can be composed of

The first to third primary coils 115_1 , 115_2 , and 115_3 may be manufactured using a printed circuit board (PCB) manufacturing method in which a coil pattern is formed in a multi-layer spiral path or a litz wire. In the case of a PCB pattern coil, the thickness is about 1~2mm, and even if three coils are overlapped, the thickness is only about 3~6mm.

Since the distance between the primary coil and the secondary coil is generally within 10 mm, the distance between the primary coil and the interface surface can be adjusted in the state where the three primary coils are unfolded according to the thickness of the primary coil.

In this way, even when the three primary coils are spread out and placed on the ferrite sheet, the distance from the interface surface is kept close, so that power transmission efficiency can be maintained even when the three primary coils are individually operated.

In addition, in the state in which the three primary coils are overlapped, the distance between the uppermost primary coil and the interface surface becomes closer, and the distance between the secondary coil of the receiving device and the overlapped primary coil is further reduced, and the primary coil and the second coil are further reduced. The coupling coefficient between the primary coils can be increased to further increase the power transmission efficiency.

8 is a diagram illustrating a connection with an inverter when each transmitting coil constituting a multi-coil is individually driven according to an embodiment of this specification, and FIG. 9 is a multi-coil constituting a multi-coil according to another embodiment of this specification It shows the connection with the inverter when the transmission coils are overlapped and connected in series to drive.

For example, when three primary coils are spread out, each primary coil may be connected to a corresponding inverter as shown in FIG. 8 in order to individually charge an electronic device mounted on the interface.

On the other hand, when moving and overlapping two of the three primary coils in order to transmit power to an electronic device with a high output, for example, 30W or more, the primary coil is connected in series as shown in FIG. 9 and one inverter is used. Three primary coils connected in series can be driven through the

To this end, a switch for controlling the connection between each inverter and each primary coil according to the unfolded state or the overlapped state of the primary coil may be provided.

10 is a functional block illustrating the configuration of a wireless power transmission module for moving a transmission coil constituting a multi-coil according to this specification.

The transmission module 100 of FIG. 10 may include a power conversion unit 110 , a communication unit 120 , a control unit 130 , a power supply unit 140 , and a coil moving unit 150 .

Since the functions of the reception module 200 and the communication unit 120 and the power supply unit 140, which are components for wireless power transmission, are similar to those described with reference to FIG. 3, descriptions thereof will be omitted.

The power converter 110 may include an inverter 111 , a resonance circuit 113 , and a switch 117 , and the functions of the inverter 111 and the resonance circuit 113 are also described with reference to FIG. 2 . Since it is the same as that described, the description is omitted.

The resonance circuit 113 may include a multi-coil 115 composed of two or more primary coils and a capacitor (not shown) connected to the primary coil.

Some of the primary coils of the multi-coil 115 may be coupled to the rail 119 so that their positions may be changed by the coil moving unit 150 .

The coil moving unit 150 may change the position of some of the primary coils 115 according to the guidance of the rail 119 , individually moving two or more primary coils constituting the multi-coil 115 , or It is also possible to move the above primary coils at the same time. In addition, the transmitting coil 115 may be moved in a first direction in which two or more coils are arranged, or the transmitting coil 115 may also be moved in a second direction perpendicular to the first direction.

The switch unit 117 may change the connection state of two or more primary coils constituting the multi-coil 115 and the inverter 111 corresponding to each primary coil.

When two or more primary coils constituting the multi-coil 115 are spread out, an inverter 111 corresponding to each primary coil may be connected so that each primary coil can transmit power to each other.

On the other hand, when the two or more primary coils constituting the multi-coil 115 change their positions so that the two or more primary coils overlap each other, the superimposed superimposed power can be transmitted to the electronic device placed in the overlapped position Two or more primary coils may be connected in series with each other, and the series connected primary coils may be connected to one inverter 111 .

Alternatively, even if the primary coils overlap each other, each primary coil is connected to a corresponding inverter 111 without connecting two or more overlapping primary coils in series with each other, but the controller 130 controls each inverter 111 It is also possible to control so that the operation timings of the respective driving circuits composed of the inverter and the resonance circuit are identical to each other.

The controller 130 may control the coil moving unit 150 to move the unfolded primary coil to the overlapping position or the primary coil moved to the overlapping position to the original unfolded position.

When the electronic device is not detected in the overlapping position in a state in which two or more primary coils are overlapped in the overlapping position, the controller 130 directly moves the movable primary coil among the primary coils in the overlapping position to the original unfolded position. This is to detect the electronic device when the user places the electronic device in the unfolded position.

In addition, the control unit 130 may control the switch unit 117 to change the connection between each primary coil and the corresponding inverter 111 , and when the primary coil is in an unfolded position, the primary coil corresponds to the primary coil. connected one to one to the inverter 111 to can

Also, the controller 130 may determine whether to move the primary coil and a connection state between the coil and the inverter according to a combination of a position where the electronic device is placed in the active area and the number of electronic devices.

For example, the control unit 130 does not move the primary coil when the electronic device is placed in a position where the movable primary coil is unfolded.

Also, when the electronic device is placed only at the position where the primary coils overlap, the controller 130 may move the movable primary coil to the overlapping position.

In addition, when one electronic device is placed in an overlapping position and one is also placed in a first position in which the primary coil is unfolded, the control unit 130 is configured to control the primary coil in a second position in which the electronic device is not placed among the positions in which the primary coil is unfolded. may be moved to the overlapping position, and the primary coil spread at the first position where the electronic device is placed may not be moved.

11 is a flowchart illustrating a method of wirelessly charging a plurality of electronic devices simultaneously through a multi-coil or wirelessly charging a large-capacity electronic device by overlapping multi-coils according to this specification.

The control unit 130 drives an operation circuit (inverter connected to the first primary coil) of the movable first primary coil Coil_1 to move the first primary coil Coil_1 to a first position where the electrons are spread out. A detection signal for confirming whether the device is placed is output (S111).

The control unit 130 checks the response signal (S112), if there is a response signal (YES in S112), determines that the electronic device including the power receiving module is placed in the first position, the first primary coil (Coil_1) ) to transmit power through the first primary coil (Coil_1) by controlling the operation circuit (S113).

The control unit 130 drives an operation circuit (inverter connected to the third primary coil) of the movable third primary coil Coil_3 to move the third primary coil Coil_1 to a third position where the electrons are spread out. A detection signal for confirming whether the device is placed is output (S114).

The control unit 130, by checking the response signal (S115), if there is a response signal (YES in S115), determines that the electronic device including the power receiving module is placed in the third position, the third primary coil (Coil_3) ) to transmit power through the third primary coil (Coil_1) by controlling the operation circuit (S116).

The control unit 130 drives an operation circuit (inverter connected to the second primary coil) of the second primary coil Coil_2 fixed at the second position to check whether the electronic device is placed at the second position Outputs a detection signal for (S117).

The control unit 130 checks the response signal (S118), if there is a response signal (YES in S118), determines that the electronic device including the power receiving module is placed in the second position, the first position or the third position Also, it is checked whether the electronic device is placed and being charged, that is, whether the primary coil (Coil_1) or the third coil (Coil_3) is operating to transmit power (S119).

If the first primary coil (Coil_1) or the third coil (Coil_3) is performing an operation (YES in S119), the controller 130 controls the operation circuit of the second primary coil (Coil_2) to the third Power is transmitted through the primary coil (Coil_1) (S120).

On the other hand, if the first primary coil (Coil_1) and the third coil (Coil_3) are not performing an operation (NO in S119), the controller 130 transmits power to the electronic device placed in the second position with high output. For this, the first primary coil (Coil_1) and the third coil (Coil_3) are moved to the second position, and the first to third primary coils (Coil_1, Coil_2, Coil_3) are connected in series and the primary coil connected in series is connected to one inverter (S121).

In addition, the controller 130 may transmit power to the electronic device placed in the second position at a high output through the first to third primary coils Coil_1 , Coil_2 , and Coil_3 connected in series ( S122 ).

In step S119, when only one of the first primary coil (Coil_1) and the third primary coil (Coil_3) is operating, the primary coil that is not operating in steps S121 and S122 is moved to the second position and moved 1 The primary coil and the second primary coil may be connected in series and power may be transmitted to the electronic device through the series-connected primary coil.

The controller 130 may transmit power while synchronizing operation timings of each inverter with each other while maintaining a state connected to the respective inverters without connecting the primary coils in series in step S121 .

Steps S111, S114, and S117 of outputting a detection signal for detecting the electronic device placed on the interface are not sequentially performed, but may be performed simultaneously.

12 shows an exploded perspective view of a charger according to this specification.

The wireless power transmission device or charger 1 that provides inductive power to an electronic device may have a seating surface having an operation area on which an electronic device including a receiving module to be charged is placed on the top surface, and the electronic device is located on the seating surface. When placed, the charger can detect it and start wireless charging.

In the charger 1 , a primary coil 115 constituting the resonance circuit 113 of the transmission device may be mounted between the front case 161 and the rear case 162 . The primary coil 115 is a multi-coil composed of two or more PCB coils spaced apart by a predetermined interval, and some of them are combined with the coil moving unit 150 to change their position along the rail 119 .

The coil moving unit 150 is connected to the transmitting coil 115 to move each coil constituting the multi-coil 115 , and while moving the coil along the rail 119 , the position of the coil in the vertical direction is can change In a state in which each coil is unfolded, the positions in the vertical direction at which each coil is arranged are equal to each other, so that the distance to the interface surface of the charger 1 is the same. In addition, the rail 119 for guiding the moving coil in order to allow the one or more coils to move to the overlapping position so that the two or more coils can be overlapped at the overlapping position may be designed to include a section in which the position in the vertical direction is changed. .

In a state in which the primary coil is unfolded, a plurality of electronic devices may be simultaneously charged with the same efficiency, and in a state in which the primary coils are overlapped, the electronic device may be charged with high output.

A shield 170 may be formed under the primary coil 115 . That is, the shielding unit 170 may be formed between the rear case 162 of the charger 100 and the transmission coil 115 , and at least a portion of the outer side of the primary coil 115 is formed to exceed. can be

The shielding unit 170 is mounted on a circuit board (not shown) by the operation of the primary coil 115 to configure the inverter 111 , the communication unit 120 and the control unit 130 of the transmission device, a microprocessor, a memory It is possible to prevent the primary coil 115 from being electromagnetically influenced by elements such as, or by the operation of elements mounted on the circuit board, and may be made of stainless steel or titanium material that does not require plating.

In addition, a ferrite sheet (not shown) is provided between the primary coil 115 and the circuit board (not shown), and electromagnetic interference such as eddy current generated in the primary coil 115 or the circuit board is different. can be done so as not to affect

The charger 1 is formed in a structure in which a power conversion unit including a primary coil, a communication unit, a control unit, a power supply unit, etc. are provided in one body, or a first body and a second body in which the transmitting coil and the shielding unit 170 are mounted. The first body may be separated into a second body including a conversion unit, a communication unit, a control unit, a power supply unit, etc. for controlling the operation of the transmitting coil.

In addition, an output unit such as a display or a speaker, a user input unit, a socket for supplying power, or an interface to which an external device is coupled may be disposed on the body of the charger 1 . A display may be formed on the upper surface of the front case 161 to indicate whether the receiving device is aligned, and a user input unit and a socket may be disposed on the side of the body.

In particular, the charger 1 may inform the user that charging is not possible in the original position of the primary coil moved to the overlapping position during wireless charging at the overlapping position in a state in which two or more primary coils are overlapped.

That is, the charger 1 displays a predetermined display at the first position in which the primary coil is unfolded, but when the primary coil is in the first position, the first display state to indicate that charging is possible in the first position; When the primary coil is moved from the first position to the overlapping position, the state of the second display indicating that the first position is not able to charge may be different from each other. In this case, the second display state may be a state in which nothing is displayed.

Accordingly, when the first position in which the moving primary coil is placed in an unfolded state is displayed as the second display state, the user determines that the first position is a position where wireless charging is not possible and does not put the electronic device to be charged on the first display You may be prompted to place the electronic device in another location indicated by the status.

Accordingly, it is possible to wirelessly charge a plurality of electronic devices at the same time with the same efficiency in a state in which the primary coil is unfolded, and also wirelessly charge an electronic device placed in an overlapping position in a state in which two or more primary coils are overlapped with high output and high efficiency. be able to do In addition, even when the primary coil changes its position, the user can easily check the charging position.

The wireless power transmission apparatus and method described in this specification may be described as follows.

A wireless power transmission device according to an embodiment, including a first coil and a second coil that are spaced apart, for transmitting power to the secondary coil of the receiving device, two or more primary coils; an inverter that converts direct current power into alternating current and supplies it to two or more primary coils, including a number corresponding to the number of two or more primary coils; and a coil moving unit for moving at least a first coil among the two or more primary coils, wherein the coil moving unit moves the first coil from the first position to a second position where the second coil is located so as to move the first coil from the second position to the first position. The coil and the second coil may be overlapped.

In one embodiment, the first coil at the first position and the second coil at the second position may be located at the same first height with respect to the vertical direction.

In an embodiment, the first coil may move from a first height to a second height higher than the first height in a vertical direction when moving from the first position to the second position.

In one embodiment, the wireless power transfer device further comprises a rail for guiding the movement of the first coil between the first position and the second position, wherein the rail moves the first coil to the first position at a first height. a first portion for guiding, a second portion for guiding the first coil to a second position at a second height, and a third portion inclined between the first portion and the second portion by a difference of the first height and the second height. can

In one embodiment, the wireless power transmitter may be configured to further include a switch for controlling the connection of two or more primary coils and the inverter.

In an embodiment, the switch unit may connect the first coil to the corresponding first inverter and connect the second coil to the corresponding second inverter when the first coil is in the first position.

In an embodiment, the switch unit may connect the first coil and the second coil in series when the first coil is in the second position, and connect the series-connected first coil and the second coil to one inverter.

In one embodiment, the primary coil may be a coil of a PCB pattern.

In an embodiment, the wireless power transmitter further includes a ferrite sheet disposed under the primary coil, and the second coil may be fixed to the ferrite sheet.

In an embodiment, the primary coil further includes a third coil moving from a third position different from the first position to a second position by the coil moving unit, and the first coil and the third coil are centered on the second coil. may be disposed at an angle of 60 degrees, 90 degrees, 120 degrees or 180 degrees.

A wireless power transmission method according to another embodiment includes: when the electronic device is placed in a first position, wirelessly transmitting power to the electronic device through a first coil; when there is no electronic device in the first position and the electric device is placed in the second position, moving the first coil to the second position to overlap the second coil; and wirelessly transmitting power to the electronic device placed at the second position through the first coil and the second coil.

In an embodiment, the overlapping may include series-connecting the overlapping first coil and the second coil at the second position and connecting the series-connected first coil and the second coil to one inverter.

The present invention is not limited to the described embodiments, and it is apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the present invention. Accordingly, it should be said that such modifications or variations are included in the claims of the present invention.

1: wireless power transmission device 2: electronic device
100: wireless power transmission module 110: power conversion unit
111: inverter 113: resonant circuit
115: primary coil 117: switch unit
119: rail 120: communication unit
130: control unit 140: power unit
150: coil moving unit 161: front case
162: rear case 170: shield
200: wireless power receiving module 210: power receiving unit
220: communication unit 230: control unit
240: load

Claims (12)

Two or more primary coils, including a first coil and a second coil disposed to be spaced apart, for transmitting power to the secondary coil of the receiving device;
an inverter that converts direct current power into alternating current and supplies it to the two or more primary coils, the inverter including a number corresponding to the number of the two or more primary coils;
Doedoe comprising a coil moving part for moving at least the first coil among the two or more primary coils,
The coil moving unit moves the first coil from a first position to a second position where the second coil is located so that the first coil and the second coil are overlapped at the second position. The method of claim 1,
The wireless power transmitter, characterized in that the first coil in the first position and the second coil in the second position are positioned at the same first height with respect to the vertical direction. 3. The method of claim 2,
The first coil, when moving from the first position to the second position, wireless power transmission device, characterized in that moving from the first height to a second height higher than the first height in the vertical direction . 4. The method of claim 3,
and a rail for guiding movement of the first coil between the first position and the second position;
The rail includes a first portion guiding the first coil to the first position to the first height, a second portion guiding the first coil to the second position to the second height, and the first portion and a third portion inclined by a difference between the first height and the second height between the second portion and the wireless power transmitter. The method of claim 1,
Wireless power transmission device, characterized in that it further comprises a switch for controlling the connection between the two or more primary coils and the inverter. 6. The method of claim 5,
The switch unit, when the first coil is in the first position, connects the first coil to a corresponding first inverter, and connects the second coil to a corresponding second inverter. transmission device. 7. The method of claim 6,
The switch unit, when the first coil is in the second position, connects the first coil and the second coil in series, and connects the series-connected first coil and the second coil to one inverter A wireless power transmission device. The method of claim 1,
The primary coil is a wireless power transmission device, characterized in that the coil of the PCB pattern. The method of claim 1,
Further comprising a ferrite sheet disposed under the primary coil,
The second coil is a wireless power transmission device, characterized in that fixed to the ferrite sheet. The method of claim 1,
The primary coil further includes a third coil moving from a third position different from the first position to the second position by the coil moving unit,
The first coil and the third coil are wireless power transmitter, characterized in that disposed at an angle of 60 degrees, 90 degrees, 120 degrees or 180 degrees with respect to the second coil. wirelessly transmitting power to the electronic device through a first coil when the electronic device is placed in the first position;
moving the first coil to the second position to overlap the second coil when there is no electronic device in the first position and an electric device is placed in the second position; and
and transmitting power wirelessly to the electronic device placed at the second position through the first coil and the second coil. 12. The method of claim 11,
The overlapping step may include serially connecting a first coil and a second coil overlapped at the second position, and connecting the series-connected first coil and the second coil to one inverter. A wireless power transfer method.

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