KR20210031668A - Wireless power transmission device which enables to simultaneously charge - Google Patents

Abstract

The present invention relates to a wireless power transmission device which comprises: a plurality of transmission blocks including two or more primary coils; and a transmission control unit in which when a plurality of wireless power reception devices are placed in a charging position, by using a response signal from the primary coil corresponding to the charging positions, the plurality of primary coils corresponding to the wireless power reception device are selected, and the transmission blocks are controlled so that a wireless power signal is transmitted from the selected plurality of primary coils at the same time.

Description

Wireless power transmission device capable of simultaneous multi-charging {WIRELESS POWER TRANSMISSION DEVICE WHICH ENABLES TO SIMULTANEOUSLY CHARGE}

The present invention relates to a wireless power transmission device capable of simultaneous multi-charging.

In general, in order to charge a portable terminal such as a mobile phone, a notebook computer, or a PDA, the portable terminal must receive electric energy (or power) from an external charger. Such a portable terminal includes a battery cell for storing supplied electric energy and a circuit for charging and discharging the battery cell (supplying electric energy to the portable terminal).

The electrical connection method between the charger and the battery cell for charging electric energy in the battery cell is to supply electric energy to the battery cell through the terminal of the battery cell by receiving commercial power and converting it into voltage and current corresponding to the battery cell. Includes terminal supply method.

This terminal supply method is accompanied by the use of a physical cable or wire. Therefore, when a lot of terminal-supplying equipment is handled, many cables take up considerable work space, are difficult to organize, and are not good in appearance. In addition, the terminal supply method may cause problems such as instantaneous discharge due to different potential differences between terminals, burnout and fire, natural discharge, and deterioration of the life and performance of the battery pack.

Recently, in order to solve the above problems, a charging system using a wireless power transmission method (hereinafter, a wireless power transmission system) and a control method have been proposed. The wireless power transmission method is also referred to as a contactless power transmission method or a no point of contact power transmission method. The wireless power transmission system includes a wireless power transmission device that supplies electric energy through a wireless power transmission method, and a wireless power reception device that charges a battery cell by receiving electrical energy wirelessly supplied from the wireless power transmission device.

Such a wireless power transmission device may include a transmission coil, a shielding material installed to surround the transmission coil, and a controller and an adapter for controlling the transmission of a power signal from the transmission coil.

In such a wireless power transmission system, it is usually possible to charge only one wireless power receiving device. Accordingly, in the case of simultaneous charging of a plurality of wireless power receiving devices, a plurality of wireless power transmitting devices must be installed and operated, which causes a significant cost burden on the user and increases power consumption.

The present invention has been devised to solve the above-described object, and provides a wireless power transmission device capable of simultaneous multi-charging capable of lowering initial standby power, lowering a detection error rate of a wireless power receiving device, and increasing wireless power transmission efficiency. It is to do.

A wireless power transmission device capable of simultaneous multi-charging according to an embodiment of the present invention conceived to solve the above-described problems includes: a plurality of transmission blocks, including two or more primary coils; And when a plurality of wireless power receiving devices are placed in a charging position, by using a response signal from a primary coil corresponding to the charging positions, a plurality of primary coils corresponding to the wireless power receiving device are selected, and the selected It may include a transmission control unit for controlling the transmission blocks to simultaneously transmit wireless power signals from a plurality of primary coils.

Here, the transmission block includes: an object detection unit that transmits a response signal generated according to the wireless power reception device to the primary coil to the transmission control unit; A converter connected to each of the primary coils; And a driving driver that transmits a driving signal only to the primary coil sensed by the object detection unit under control of the transmission control unit.

Here, the wireless power transmission device capable of simultaneous multi-charging may further include an adapter that converts external AC power into DC power and supplies power for the wireless power signal.

Here, the adapter is installed to be replaceable according to the number of the primary coil, a wireless power transmission device capable of simultaneous multi-charging.

Herein, the wireless power transmission device capable of simultaneous multi-charging further includes a temperature sensor, and the transmission control unit includes, if the temperature measured from the temperature sensor is greater than or equal to a reference value while the wireless power signal is simultaneously transmitted, the wireless power signal You can restrict the transmission of all.

Here, the transmission control unit may control the output of the wireless power signal based on the state of charge information transmitted through the primary coil.

Here, the response signal is a signal strength packet signal for digital ping, and the transmission control unit may control to generate a wireless power signal in all of the primary coils when the response signal is received from all of the primary coils. .

Here, the transmission control unit, after transmitting the wireless power signal at an intersection with respect to the primary coil, by analyzing the state of charge information from the wireless power receiving device, the current value rectified in the wireless power receiving device is equal to or greater than a reference value 1 When a primary coil is identified, it is selected as the best primary coil and controlled to oscillate a wireless power signal through it, and when the current value rectified in the wireless power receiving device is less than a reference value, wireless power is performed in all of the primary coils. The signal can be controlled to oscillate.

According to the wireless power transmission device capable of simultaneous multi-charging according to an embodiment of the present invention having the above-described configuration, it is possible to simultaneously charge a plurality of wireless power receiving devices.

Furthermore, by partitioning the wireless power transmission device for each transmission block, initial standby power is greatly reduced, the efficiency for detecting foreign substances during charging is increased, and power transmission efficiency can be increased.

1 is a view for explaining an operation mode of a wireless power transmission device capable of simultaneous multi-charging according to an embodiment of the present invention.
2 is a view for explaining the electronic configuration of a wireless power transmission device capable of simultaneous multi-charging according to an embodiment of the present invention.
3 is a flowchart illustrating a method of performing foreign matter detection in a wireless power transmission system including a wireless power transmission device capable of simultaneous multi-charging according to an embodiment of the present invention.
4 is a flowchart illustrating a method of performing foreign matter detection in a wireless power transmission system including a wireless power transmission device capable of simultaneous multi-charging according to another embodiment of the present invention.
5 is a flowchart illustrating a method of performing foreign matter detection in a wireless power transmission system including a wireless power transmission device capable of simultaneous multi-charging according to another embodiment of the present invention.
6 is a flowchart illustrating a method of performing foreign matter detection in a wireless power transmission system including a wireless power transmission device capable of simultaneous multi-charging according to an embodiment of the present invention.
7 is a flowchart illustrating an operation of a wireless power transmission system in a wireless power transmission system including a wireless power transmission device capable of simultaneous multi-charging according to another embodiment of the present invention.
8 is a flowchart illustrating an operation of a wireless power transmission system including a wireless power transmission device capable of simultaneous multi-charging according to another embodiment of the present invention.

Hereinafter, a wireless power transmission device capable of simultaneous multi-charging according to the present invention will be described in more detail with reference to the drawings. The suffixes "module" and "unit" for constituent elements used in the following description are given or used interchangeably in consideration of only the ease of writing the specification, and do not themselves have a distinct meaning or role from each other.

1 is a diagram for explaining an operation mode of a wireless power transmission device capable of simultaneous multi-charging according to an embodiment of the present invention. As shown in FIG. 1, in the wireless power transmission apparatus 100 according to the present invention, a plurality of coils are arranged in a matrix form, and each coil is formed to be spaced apart. In this case, a plurality of wireless power receiving devices 200 such as a smartphone may be placed in a charging position at the same time. In this case, the wireless power transmission device 100 oscillates a wireless power signal suitable for each of the plurality of wireless power reception devices 200. Accordingly, power is simultaneously supplied to the plurality of wireless power receiving apparatuses 200.

Hereinafter, with reference to FIG. 2, an electronic configuration of the wireless power transmission device 100 capable of simultaneous multi-charging capable of performing the above-described function will be described.

FIG. 2 is a diagram illustrating an electronic configuration of a wireless power transmission device capable of simultaneous multi-charging according to an embodiment of the present invention. As shown in FIG. 2, the wireless power transmission system may include a wireless power transmission device 100, a wireless power reception device 200, and an adapter 300.

First, the adapter 300 functions to supply power for a wireless power signal oscillating to the wireless power receiving device 200 by converting an AC commercial power source into a DC power source. At this time, the adapter 300 may be configured as a switching mode power supply (SMPS). SMPS refers to a power supply device using a switching circuit. Compared to the linear power supply device used in the past, the efficiency is high, durability is strong, and it is advantageous in miniaturization and weight reduction. The adapter 300 may be installed interchangeably according to the capacity or number of transmission blocks 110 to be described later. For example, in the case of having two charging positions, the SMPS has a capacity of 12V/2A, and in the case of having four charging positions, the SMPS may have a capacity of 12V/4A.

Meanwhile, the wireless power transmission apparatus 100 according to the present invention may include at least two transmission blocks 110, a transmission control unit 120, and a temperature sensor 130.

Each of the transmission blocks 110 is, as shown in FIG. 2, a primary coil 101 forming a pair, a converter 103 connected to each of the primary coils 101, and the converter 103, respectively. It may include one driving driver 105 and an object detection unit 107 that is connected to each of the primary coils 101 and detects whether the wireless power receiving device 200 is in a charging position.

The primary coil 101 is a component that oscillates a wireless power signal, and oscillates a wireless power signal to the wireless power receiver 200 by an electromagnetic induction method. As the primary coil 101, a circular shape, an oval shape, a track shape, a square shape, a polygon shape, etc. may be used.

In the transmission block 110 in the present invention, a primary coil 101 is formed in a pair. In the present embodiment, an example in which the primary coils 101 form a pair has been described, but the present invention is not limited thereto, and the transmission block 110 may be configured with three or four primary coils.

The converter 103 generates transmission power for generating a power signal to be transmitted under the control of the driving driver 105 and supplies it to the primary coil 101. In other words, the transmission control unit 120 determines the converter 103 corresponding to the primary coil 101 in which the wireless power receiver 200 is placed at the charging position, and the determined power value of the converter 103 is determined. When a power control signal for transmitting a power signal is transmitted to the driving driver 105, the driving driver 105 selects the converter 103 in response to the transmitted power control signal and controls its operation. Accordingly, the converter 103 applies the transmission power corresponding to the power value required by the control of the driving driver 105 to the corresponding primary coil 101, so that the wireless power signal of the required intensity is applied to the charging position. It is to be transmitted to the wireless power receiving device 200 in.

The driving driver 105 controls the operation of the converter 103 through the control of the transmission control unit 120.

The object detection unit 107 detects a change in the load of the primary coil 101, detects whether there is an object in the charging position, and accordingly, the transmission control unit 120 transmits a digital ping signal to the driving driver 105 ) Is controlled to oscillate through the transmission coil, and as a response signal, a signal strength packet signal is received from the wireless power receiving device 200 to determine whether the object is caused by the wireless power receiving device 200 or not. (In other words, it has a function as an ID verification unit), and performs a function of filtering and processing charge state information transmitted from the wireless power receiving device 200. That is, when a signal including an object response signal and charge state information, which is a signal strength packet signal for a digital ping of the object detection signal transmitted through the primary coil 101, is received, it filters and processes the received signal.

The transmission control unit 120 receives and checks the determination result of the object detection unit 107, analyzes the object response signal received from the primary coil 101, and transmits wireless power through the primary coil 101. It serves to transmit a power signal for transmitting a signal to the driving driver 105. On the other hand, the transmission control unit 120, after transmitting a wireless power signal at the intersection with respect to the primary coil 101, by analyzing the charging state information from the wireless power receiving device 200, the wireless power receiving device ( When the primary coil 101 whose current value rectified in 200) is greater than or equal to the reference value is identified, it is selected as the best primary coil and controlled to oscillate a wireless power signal through it, and the wireless power receiving device 200 When the rectified current value is less than or equal to the reference value, the wireless power signal is controlled to oscillate in all of the paired primary coils 101.

The temperature sensor 130 functions to detect that the wireless power transmission device 100 is overheated due to foreign substances. If a foreign material such as a coin is placed at the charging position of the wireless power transmission device 100 during or during wireless charging, wireless power transmission is not performed normally, and accordingly, power waste occurs, and thus wireless power The transmission device 100 becomes overheated.

In the present invention, when the temperature measured by the temperature sensor 130 is equal to or higher than a reference value while the wireless power signal is simultaneously transmitted, the transmission control unit 120 functions to limit all transmission of the wireless power signal. Accordingly, it is possible to prevent abnormal waste of power.

Meanwhile, the wireless power receiving apparatus 200 receiving power by receiving a power signal includes a secondary coil 210 that generates induced power based on the transmitted power signal, and a rectifier 220 that rectifies the induced power. And a battery 230 and a reception control unit 240 charged with the rectified power.

Here, the battery cell module 230 includes a protection circuit such as an overvoltage and overcurrent prevention circuit, and a temperature sensing circuit, and also includes a charge management module that collects and processes information such as the state of charge of the battery cell. .

According to the above configuration, the present invention includes a plurality of transport blocks. Accordingly, when the wireless power receiving device 200 is placed in a charging position, the object detecting unit 107 of each of the transmission blocks 110 detects which charging position the wireless power receiving device 200 is placed in, and charging The transmission block 110 in which the wireless power receiving device 200 is not placed in the position is to be kept in a ready state, and the transmission block 110 in which the wireless power receiving device 200 is placed has a wireless power on a certain primary coil 101. It is checked whether the receiving device 200 is placed, and the driving driver is switched to drive the wireless power signal from the primary coil 101 at the corresponding position, or both converters 103 are controlled to operate.

As described above, by converting the drive driver 105, the object detection unit 107, the converter 103, and the primary coil into a transmission block, maintenance is convenient, and the standby power is greatly reduced, thereby increasing power efficiency.

Meanwhile, the primary coil 101 may be composed of two or more coils in order to increase the degree of freedom in the charging position.

As described above, if two primary coils are installed, two wireless power receivers can be charged at the same time. In this case, a 5-10W class adapter (SMPS) is used, and if four primary coils are installed In this case, four wireless power receivers can be charged at the same time, and in this case, a 10-15W class adapter (SMPS) is used.

In addition, if the primary coil 101 is separated from the main substrate, that is, the transmission block 110, the transmission control unit 120, and the temperature sensor 130 are installed on the main substrate, and one of the transmission blocks 110 If the primary coil 101 is installed separately from the main substrate, the magnetic field generated in the primary coil 101 can have a space that can minimize the influence on the substrate, and the manufacturing cost can be lowered.

3 is a flowchart illustrating a method of performing foreign matter detection in a wireless power transmission system including a wireless power transmission device capable of simultaneous multi-charging according to an embodiment of the present invention.

Referring to FIG. 3, a foreign object detection operation is performed before initial charging (S200). As an example, the operation of detecting foreign matter before initial charging is shown in FIG. 6 below.

When a foreign material is detected before initial charging (S205), a power limiting operation corresponding to the foreign material detection is performed (S225).

When a foreign material is not detected before initial charging (S205), when charging starts, a foreign material detection operation is performed during charging (S210).

For example, a foreign substance may be detected by performing one-way communication while charging. As an example, the operation of detecting foreign substances using one-way communication during charging is shown in FIG. 7 below.

As another example, a foreign substance may be detected by performing two-way communication while charging. As an example, the operation of detecting foreign substances using bidirectional communication during charging is as shown in FIG. 8 below.

As another example, while charging, the one-way communication and the two-way communication may be performed simultaneously or independently to detect foreign matter.

When a foreign material is detected during charging (S215), a power limiting operation corresponding to the foreign material detection is performed as in step S225.

When a foreign material is not detected during charging (S215), when a problem occurs in power transmission due to a fine foreign material that is not detected, power is limited based on the temperature sensor 130 (or thermistor) in order to protect the power transmission (e.g., Turn off the power) (S220). The temperature sensor may be attached to the receiving device or attached to the transmitting device.

Alternatively, even after the power limiting operation corresponding to foreign matter detection is performed in step S225, power is limited based on a temperature sensor (or thermistor) in order to protect power transmission when a problem occurs in power transmission due to a fine foreign matter that has not been detected.

4 is a flowchart illustrating a method of performing foreign matter detection in a wireless power transmission system including a wireless power transmission device capable of simultaneous multi-charging according to another embodiment of the present invention.

Referring to FIG. 4, a foreign object detection operation is performed before initial charging (S300).

When a foreign material is detected before initial charging (S305), a power limiting operation corresponding to the foreign material detection is performed (S315).

When a foreign material is not detected before initial charging (S305), when a problem occurs in power transmission due to a fine foreign material that is not detected, power is limited based on a temperature sensor (or thermistor) to protect power transmission (e.g., power is limited. Hang up) (S310). The temperature sensor may be attached to the receiving device or attached to the transmitting device.

Alternatively, even after the power limiting operation corresponding to foreign matter detection is performed in step S315, power is limited based on a temperature sensor (or thermistor) in order to protect power transmission when a problem occurs in power transmission due to a fine foreign matter that has not been detected.

5 is a flowchart illustrating a method of performing foreign matter detection in a wireless power transmission system in a wireless power transmission system including a wireless power transmission device capable of simultaneous multi-charging according to another embodiment of the present invention.

Referring to FIG. 5, when charging starts, a foreign substance detection operation is performed during charging (S400).

When a foreign substance is detected during charging (S405), a power limiting operation corresponding to the foreign substance detection is performed (S415).

When a foreign material is not detected during charging (S405), if a problem occurs in power transmission due to a fine foreign material that has not been detected, power is limited based on a temperature sensor (or thermistor) to protect power transmission (e.g., cut off the power. )(S410). The temperature sensor may be attached to the receiving device or attached to the transmitting device.

Alternatively, even after the power limiting operation corresponding to foreign matter detection is performed in step S415, power is limited based on a temperature sensor (or thermistor) in order to protect power transmission when a problem occurs in power transmission due to a fine foreign matter that has not been detected.

Now, the operation of detecting foreign matter according to the present invention will be described by dividing the first charge before and after the charge (for example, only “Use of directional communication or use of two-way communication).

One. Foreign matter detection operation before initial charging

6 is a flowchart illustrating a method of performing foreign matter detection in a wireless power transmission system including a wireless power transmission device capable of simultaneous multi-charging according to an embodiment of the present invention. This corresponds to step S200 of FIG. 2 or step S300 of FIG. 3.

Referring to FIG. 6, in a ping phase, the wireless power transmitter performs digital ping, and at this time, the wireless power transmitter transmits a power signal of an operating point to the wireless power receiver (S500).

Upon receiving the power signal of the ping phase, the wireless power receiving apparatus generates a signal strength packet indicating the received strength of the power signal and transmits it to the wireless power transmission apparatus (S505). Then, the wireless power receiver generates an identification packet indicating a unique ID of the wireless power receiver and configuration information of the wireless power receiver, and transmits the identification packet and configuration information to the wireless power transmitter (S510).

The apparatus for receiving power wirelessly measures the received power (S515). From this point, it enters the step of setting the _{initial voltage V i}

The wireless power receiving apparatus determines whether a termination reason such as over voltage power (OVP), over current power (OCP), or full charge occurs (S520). If OVP, OCP, full charge, or other type of charge reason occurs, the wireless power receiver ends the charge (S525). If the type reason does not occur, the wireless power receiving device determines whether it is in a state of receiving wireless power from the wireless power transmitting device, that is, charging (S530).

If charging in step S530, the wireless power receiving device compares the received power to the requested power, generates a power control packet based on the result, and transmits it to the wireless power transmitting device (S535). In step S535, if not charging, the wireless power receiving apparatus _{determines whether the initial voltage V i} is in a hold state (S540). When the steady state value of the initial voltage V _i exists within the reference voltage range (for example, 7.0V to 10.5V), the wireless power receiver is initially set. As a result, the initial voltage V _i is in a hold state, and the wireless power receiver can enter the foreign matter detection phase.

If _{it is not in the V i} hold state, the wireless power receiving device generates a power control packet and transmits it to the wireless power transmission device as in the case of charging (S535). If the V _i hold state, the wireless power receiver enters the foreign matter detection phase. Here, the wireless power receiving apparatus generates a foreign substance state packet and transmits it to the wireless power transmission apparatus (S545).

The foreign matter state packet according to the present invention includes a preamble, a header, a message, and a checksum. The preamble can be composed of a minimum of 11 bits to a maximum of 25 bits, and all bits can be set to 0. The preamble is used by the wireless power transmission device to accurately detect the start bit of the header of the foreign substance state packet and to synchronize the incoming data.

The header indicates the type of packet and can be composed of 8 bits. As an example, the value of the header of the foreign matter state packet may be '0x00'. In this case, the message may have a value of 0, that is, '0x00'. As another example, the header value of the foreign material status packet may be '0x05', which is the same as the header of the charge status packet. However, by setting the value of the 1-byte message of the charge status packet to '0x00', it may be indicated that the packet is a foreign material status packet. That is, the foreign matter state packet is included in the charge state packet.

The wireless power transmission apparatus checks whether the received packet is a foreign substance state packet based on the value of the header or message of the received packet. In addition, when it is determined that the foreign matter state packet has been received, the wireless power transmission device detects the foreign matter (S550). The operation of checking the foreign matter state packet and the foreign matter detection are performed by the control unit of the wireless power transmission device.

2. Foreign object detection during charging

2-1. Foreign matter detection using one-way communication during charging

7 is a flowchart illustrating an operation of a wireless power transmission system including a wireless power transmission device capable of simultaneous multi-charging according to another embodiment of the present invention. This corresponds to step S210 of FIG. 2 or step S400 of FIG. 4.

Referring to FIG. 7, the wireless power transmission device searches for a wireless power reception device (S600). At this time, the wireless power transmission device is in a charging standby state until the wireless power receiving device is found.

If the detected object is a wireless power receiver, the wireless power transmitter enters the charging mode and transmits wireless power to the wireless power receiver (S605). In the charging mode, the wireless power transmission device applies power to the primary coil to generate an induced magnetic field or resonance.

The wireless power transmission device measures a current flowing through the primary coil, and the wireless power transmission device obtains a current measurement value from the current flowing through the primary coil (S610). The current measured by the wireless power transmission device may be an alternating current. The current measurement value may be converted into a DC value suitable for recognition by the control unit in the wireless power transmission device. That is, the wireless power transmission device measures a relatively high alternating current flowing through the primary coil, and maps the measured high current to a current measurement value, which is a value suitable for the control unit to analyze, as shown in Table 1.

Rx power
(unit: W) Tx AC current
(unit: A) Max AC current
(unit: A) 2.5 0.998 1.05 3 1.328 1.5 4 1.664 1.85 5 1.925 2.05

The wireless power transmission device detects foreign matter by using any one or a combination of two or more of parameters such as a _{reference current I ref} , a reference range (I _low to I _{high ), a reference AC signal, and a foreign matter detection time t (S615).} ). In addition, parameters such as a reference current I _ref , a reference range (I _low ~ I _high ), a reference AC signal, and a foreign substance detection timing t may be pre-stored in the wireless power transmission device as initial setting values. The wireless power transmission device continuously transmits power to the wireless power reception device when no foreign matter is detected (S620). In addition, the wireless power transmission apparatus acquires the current measurement value of the primary coil again at a time t predetermined by the system or standard (S610), and attempts to detect foreign matters based on this (S615).

On the other hand, when a foreign substance is detected, the wireless power transmission device cuts off the wireless power transmitted to the wireless power reception device (S625).

2-2. Foreign matter detection operation using two-way communication during charging

8 is a flowchart illustrating an operation of a wireless power transmission system including a wireless power transmission device capable of simultaneous multi-charging according to another embodiment of the present invention.

For example, performing two-way communication means that when power is transmitted from the transmitting device to the receiving device, the receiving device notifies the received power value to the transmitting device, and if the power loss is more than a predetermined reference value, it is determined as FOD. Say what to do. For example, performing two-way communication means that when the transmitting device transmits 7 to 10W of power to the receiving device and receives 5W of power from the receiving device, the received power value '5W' is notified to the transmitting device, and the power loss is 2W. It is more than the predetermined reference value of 1W, so it is judged as FOD. Through this, the FOD can be detected in the power transmission step.

Referring to FIG. 8 in detail, the two-way communication is described in detail, the wireless power transmission apparatus searches for a wireless power reception apparatus (S700). At this time, the wireless power transmission device is in a charging standby state until the wireless power receiving device is found.

If the detected object is a wireless power receiver, the wireless power transmitter enters the charging mode and transmits wireless power to the wireless power receiver (S705). In the charging mode, the wireless power transmission device applies power to the primary coil to generate an induced magnetic field or resonance.

The wireless power transmission device transmits a transmission power measurement report indicating the measured transmission power to the wireless power reception device (S710). For example, the wireless power transmission device transmits a transmission power measurement report to the wireless power reception device as an FSK signal. Here, the FSK signal refers to a signal transmitted using the FSK method.

The FSK signal may include a simple amount of power (eg, amount of transmit power). In this case, the wireless power transmission device may transmit the FSK signal at a constant period. This is because the apparatus for receiving power wirelessly may not know when to transmit the FSK signal. The predetermined period may be a period in which a predetermined number of data signals are transmitted (eg, an ASK signal is constant).

For example, the amount of transmission power may be a value obtained by measuring the power generated by the main coil according to the AC current signal by the wireless power transmission device.

The FSK signal switches or selects a variable frequency (e.g., 140 or 140.3 Khz) in a certain range for converting one fixed power frequency (f _{0, for example, 145 kHz) required by the receiving device.} Thus, it refers to a signal that transmits 0 and 1 values. As another example, it refers to a signal that transmits a data signal including a 0 value and a 1 value using a phase.

For example, the wireless power transmission device may measure power generated by the main coil according to the AC current signal, configure a transmission power measurement report indicating the measured generated power, and transmit it to the wireless power receiving device. In this way, control information is transmitted from the wireless power transmitter to the wireless power receiver (for example, control information may be transmitted as an FSK signal), or from the wireless power receiver to the wireless power transmitter. Two-way communication through which control information is transmitted is possible.

The wireless power transmission device performs PWM using an inverter, and generates a frequency allowed for the required power (or required power) of the wireless power receiving device.

The required power of the wireless power receiver generates a duty cycle or voltage, and the duty cycle or voltage value is the power value of the wireless power transmitter. That is, the power of the wireless power transmission device may be represented by a voltage applied to the inverter, a duty setting, and a frequency.

In the step of transmitting power by the wireless power transmission device, a set value (eg, voltage, duty frequency) is transmitted to the wireless power reception device in an FSK method.

At this time, the wireless power receiver stops receiving the existing data signal (eg, ASK signal) and receives the FSK signal. For example, the reception operation of the FSK signal includes a demodulation operation of the FSK signal.

The FSK signal may be transmitted at a constant period 750. For example, the constant period 750 may be a transmission period of a predetermined time (eg, 3 seconds and 5 seconds) or a predetermined number of data signals (eg, ASK signals).

The FSK signal may be transmitted simultaneously with wireless power. That is, S705 and S710 may be performed simultaneously.

Subsequently, the wireless power receiving device detects a foreign object based on the transmission power measurement report (S715). For example, the FSK signal including the received power value measured by the wireless power receiver and the generated power measurement report is calculated, and if the difference value is greater than or equal to a predetermined reference value, it is determined as FOD. As another example, the wireless power receiving apparatus determines as FOD if the'receive power-transmission energy' is equal to or greater than a predetermined reference value.

For example, the measured received power value may be information indicating whether a difference between the power indicated by the transmission power measurement report and the requested power is greater than, equal to, or less than a threshold. For example, if the difference between the power indicated by the transmission power measurement report and the requested power is greater than the threshold, the'received power measurement result = 1'is set, and the difference between the power indicated by the transmission power measurement report and the requested power is the threshold. If it is less than or equal to,'received power measurement result = 0'may be set. Or, conversely, when the difference between the power indicated by the transmission power measurement report and the required power is greater than or equal to the threshold,'received power measurement result = 1'is set, and the difference between the power indicated by the transmission power measurement report and the required power is When it is less than the threshold, it may be set to'receive power measurement result = 0'. For example, let's say the threshold is 1W. As in the above example, in a situation where the power indicated by the transmission power measurement report is 12W and the required power is 10W, the difference is 2W, which is greater than the threshold value of 1W. In this case, the reception power measurement result indicates 1. If the difference between the power indicated by the transmission power measurement report and the required power is greater than the threshold, this may mean that a foreign substance has been detected. Accordingly, the wireless power transmission device 40 may recognize this as a foreign object detection declaration.

The wireless power receiving device transmits an ASK signal including a foreign substance detection result to the wireless power transmitting device (S720).

The ASK signal may include a power control signal, an FOD detection signal, an emergency signal or a buffer signal.

In addition, the ASK signal may include information on required power of the wireless power receiving device. The required power information refers to information that requests the wireless power transmission device to generate wireless power based on a magnetic induction method, and the wireless power transmission device checks the required power information and generates a control signal so that the power indicated in the requested power information is induced. This is the information to be generated. For example, when the requested power information indicates 10W, the wireless power transmission apparatus generates a control signal so that 10W is transmitted.

The ASK signal may be transmitted in the form of a control error packet, a rectified packet, or a charger state.

Subsequently, the wireless power transmission device may transmit wireless power based on the received ASK signal (S725).

Since it is impossible to transmit and receive data signals (eg, ASK signal or FSK signal) at the same time, transmission or reception is performed sequentially. On the other hand, since power is continuously generated through the induction frequency, it is possible to transmit the power signal and the data signal at the same time. Accordingly, wireless power may be transmitted simultaneously or at any time regardless of the time point at which the ASK signal and the FSK signal are transmitted/received.

According to the steps S720 and S725, the ASK signal and the wireless power may be transmitted and received a plurality of times.

When a certain period 750 elapses with respect to step S710, the wireless power transmission apparatus transmits a transmission power measurement report indicating the measured transmission power to the wireless power reception apparatus (S730). For example, the wireless power transmission device transmits a transmission power measurement report to the wireless power reception device as an FSK signal. The constant period 750 may be a transmission period of a predetermined time (eg, 3 seconds and 5 seconds) or a predetermined number of data signals (eg, ASK signals).

On the other hand, if it is determined that the foreign matter is detected by the wireless power receiving device, the wireless power transmission device may perform a measure for detecting the foreign matter (not shown in the drawing). For example, the wireless power transmission device may enter a cut-off mode in which driving of the main coil is reduced or stopped. As a result, heat generation of the parasitic load may be prevented, and the supply of inefficient induced power may be limited or stopped.

According to the wireless power transmission device capable of simultaneous multi-charging according to an embodiment of the present invention having the above-described configuration, it is possible to simultaneously charge a plurality of wireless power receiving devices.

Furthermore, by partitioning the wireless power transmission device for each transmission block, initial standby power is greatly reduced, the efficiency for detecting foreign substances during charging is increased, and power transmission efficiency can be increased.

The wireless power transmission device capable of simultaneous multi-charging described above is not limited to the configuration and method of the above-described embodiments, but the embodiments are all or part of each of the embodiments so that various modifications can be made. May be configured by selectively combining.

100: wireless power transmission device
101: primary coil (transmission coil)
103: converter
105: drive driver
107: object detection unit
110: transmission block
120: transmission control unit
130: temperature sensor
200: wireless power receiving device
210: secondary coil (receive coil)
220: rectifier
230: battery
240: receiving control unit
300: Adapter (SMPS)

Claims (6)

A plurality of transmission blocks including two or more primary coils;
A transmission control unit that selects a plurality of primary coils using response signals from the primary coils, and controls the transmission blocks to simultaneously transmit wireless power signals from the selected plurality of primary coils; And
As an adapter for supplying power of the wireless power signal, the adapter is installed to be replaced according to the number of the primary coil, the adapter
Containing, a wireless power transmission device capable of simultaneous multi-charge. The method of claim 1,
The transport block,
An object detection unit transmitting a response signal generated by a plurality of wireless power receiving devices to the primary coil to the transmission control unit;
A converter connected to each of the primary coils; And
A wireless power transmission device capable of simultaneous multi-charging, including a driving driver, that transmits a driving signal only to the primary coil sensed by the object detection unit under the control of the transmission control unit. The method of claim 1,
Further comprising a temperature sensor,
The transmission control unit,
If the temperature measured by the temperature sensor is equal to or higher than a reference value while the wireless power signal is simultaneously transmitted, the wireless power transmission device capable of simultaneous multi-charging is configured to limit all transmission of the wireless power signal. The method of claim 1,
The transmission control unit,
Controlling the output of the wireless power signal, based on the charging state information transmitted through the primary coil, a wireless power transmission device capable of simultaneous multi-charging. The method of claim 3,
The transmission control unit,
When a signal strength packet signal for a digital ping is received from all of the primary coils, a wireless power transmission device capable of simultaneous multi-charging is controlled to generate a wireless power signal in all of the primary coils. The method of claim 5,
The transmission control unit,
After transmitting a wireless power signal at an intersection with respect to the primary coil, the state of charge information from a plurality of wireless power receiving devices is analyzed, and a primary coil having a current value rectified in the wireless power receiving device equal to or greater than a reference value is identified. , It is selected as the best primary coil and controlled to oscillate a wireless power signal through it, and when the current value rectified in the wireless power receiving device is less than or equal to a reference value, controlling the wireless power signal to oscillate in all of the primary coils. , Wireless power transmission device capable of simultaneous multi-charging.

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