KR20230169045A - Wireless power transmission device which enables to simultaneously charge - Google Patents

Abstract

The present invention includes a plurality of transmission blocks, including two or more primary coils ; And when the plurality of wireless power receiving devices are placed in the charging position, using response signals from the primary coils corresponding to the charging positions, select the plurality of primary coils corresponding to the wireless power receiving devices, and select the plurality of primary coils corresponding to the wireless power receiving devices. It relates to a wireless power transmission device capable of simultaneous multi-charging, including a transmission control unit that controls the transmission blocks to simultaneously transmit wireless power signals from a plurality of primary coils.

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.

Generally, in order for a portable terminal such as a mobile phone, laptop, or PDA to be charged, the portable terminal must receive electrical energy (or power) from an external charger. These portable terminals include battery cells that store supplied electrical energy and circuits for charging and discharging the battery cells (supplying electrical energy to the portable terminal).

The electrical connection method between a charger and a battery cell to charge electric energy to a battery cell is to receive commercial power, convert it into voltage and current corresponding to the battery cell, and supply electric energy to the battery cell through the terminal of the battery cell. Includes terminal supply method.

This terminal supply method involves the use of physical cables or wires. Therefore, when handling a lot of terminal-supplied equipment, many cables take up a considerable amount of work space, are difficult to organize, and do not look good. In addition, the terminal supply method can cause problems such as instantaneous discharge phenomenon due to different potential differences between terminals, burnout and fire caused by foreign substances, natural discharge, and deterioration of the life and performance of the battery pack.

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

This wireless power transmission device may include a transmission coil, a shielding material installed to surround the transmission coil, and a control unit and adapter that control the transmission of a power signal from the transmission coil.

In such a wireless power transmission system, only one wireless power receiving device can usually be charged. Therefore, when attempting to charge multiple wireless power receiving devices at the same time, multiple wireless power transmitting devices must be installed and operated, which not only imposes a significant cost burden on the user but also causes many problems such as increased power consumption.

The present invention was conceived to solve the above-mentioned object, and provides a wireless power transmission device capable of simultaneous multi-charging, which can reduce initial standby power, reduce the detection error rate of the wireless power receiving device, and increase wireless power transmission efficiency. It is for this purpose.

A wireless power transmission device capable of simultaneous multi-charging, which is an embodiment of the present invention devised to solve the above-described problem, includes a plurality of transmission blocks including two or more primary coils ; And when the plurality of wireless power receiving devices are placed in the charging position, using response signals from the primary coils corresponding to the charging positions, select the plurality of primary coils corresponding to the wireless power receiving devices, and select the plurality of primary coils corresponding to the wireless power receiving devices. It may include a transmission control unit that controls the transmission blocks so that wireless power signals are transmitted simultaneously from a plurality of primary coils.

Here, the transmission block includes: an object detection unit that transmits a response signal generated by 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 sends a driving signal only to the primary coil detected by the object detection unit under the 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 alternating current power into direct current power and supplies power of the wireless power signal.

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

Here, the wireless power transmission device capable of simultaneous multi-charging further includes a temperature sensor, and the transmission control unit is configured to transmit the wireless power signal when the temperature measured from the temperature sensor is greater than a reference value while the wireless power signal is simultaneously transmitted. All transmissions can be restricted.

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

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

Here, the transmission control unit transmits an alternating wireless power signal to the primary coil and then analyzes the charging state information from the wireless power receiving device, so that the current value rectified by the wireless power receiving device is 1 or more than the reference value. When a secondary coil is confirmed, 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 below the reference value, wireless power is supplied from all of the primary coils. The signal can be controlled to oscillate.

According to the wireless power transmission device capable of simultaneous multi-charging, which is an embodiment of the present invention having the above-described configuration, a plurality of wireless power reception devices can be charged simultaneously.

Moreover, by partitioning the wireless power transmission device into transmission blocks, initial standby power can be greatly reduced, efficiency in detecting foreign substances during charging can be increased, and power transmission efficiency can be increased.

1 is a diagram illustrating the operation of a wireless power transmission device capable of simultaneous multi-charging, which is an embodiment of the present invention.
FIG. 2 is a diagram illustrating the electronic configuration of a wireless power transmission device capable of simultaneous multi-charging, which is an embodiment of the present invention.
Figure 3 is a flowchart showing a method of detecting foreign matter 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.
Figure 4 is a flowchart showing a method of detecting foreign matter 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.
Figure 5 is a flowchart showing a method of detecting foreign matter 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.
Figure 6 is a flowchart illustrating a method of detecting foreign matter 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.
Figure 7 is a flowchart of the 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.
Figure 8 is an operation flow chart 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 related to the present invention will be described in more detail with reference to the drawings. The suffixes “module” and “part” for components used in the following description are given or used interchangeably only for the ease of preparing the specification, and do not have distinct meanings or roles in themselves.

Figure 1 is a diagram for explaining the operation of a wireless power transmission device capable of simultaneous multi-charging, which is an embodiment of the present invention. As shown in FIG. 1, the wireless power transmission device 100 according to the present invention includes a plurality of coils arranged in a matrix form, and each coil is spaced apart. At this time, a plurality of wireless power receiving devices 200, such as a smartphone, can be placed in the 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 supplied to a plurality of wireless power receiving devices 200 simultaneously.

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

FIG. 2 is a diagram illustrating the electronic configuration of a wireless power transmission device capable of simultaneous multi-charging, which is 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 convert AC commercial power to DC power and supply power to the wireless power signal oscillating to the wireless power receiver 200. 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 previously, SMPS is more efficient, more durable, and advantageous for being compact and lightweight. This adapter 300 can be installed to be exchangeable depending on the capacity or number of transmission blocks 110, which will be described later. For example, when it has two charging positions, the SMPS can have a capacity of 12V/2A, and when it has four charging positions, it can have a capacity of 12V/4A.

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

As shown in FIG. 2, each of the transmission blocks 110 includes a paired primary coil 101, a converter 103 connected to each of the primary coils 101, and a converter 103 connected to each of the converters 103. 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 receiving device 200 using electromagnetic induction. The primary coil 101 may be circular, oval, track-shaped, square, or polygonal in shape.

In the present invention, the transmission block 110 is paired with a primary coil 101. In this embodiment, an example in which the primary coils 101 form a pair has been described, but the present invention is not limited to this, and the transmission block 110 may be composed of 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 where the wireless power receiving device 200 is placed at the charging position, and the determined converter 103 generates the required power value. When a power control signal for transmitting a power signal with 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 transmitted 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 control of the transmission control unit 120.

The object detection unit 107 detects a change in the load of the primary coil 101 and detects whether there is an object at the charging location. Accordingly, the transmission control unit 120 sends 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. (That is, it functions as an ID confirmation unit) and performs a function of filtering and processing charging state information transmitted from the wireless power receiving device 200. That is, when a signal including an object response signal and charging state information, which is a signal strength packet signal for the digital ping of the object detection signal transmitted through the primary coil 101, is received, it filters and processes the signal.

The transmission control unit 120 receives and confirms 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. Meanwhile, the transmission control unit 120 transmits an intersection wireless power signal to the primary coil 101 and then analyzes the charging state information from the wireless power reception device 200 to determine the wireless power reception device ( When the primary coil 101 whose rectified current value is greater than the reference value is confirmed in 200), this 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 below the reference value, the wireless power signal is controlled to oscillate in both primary coils 101 forming the pair.

The temperature sensor 130 functions to detect that the wireless power transmission device 100 is overheated due to foreign substances. If a metallic foreign object, such as a coin, is placed at the charging position of the wireless power transmission device 100 during or at the beginning of wireless charging, wireless power transmission will not be performed normally, and accordingly, power waste will occur, thereby causing wireless power transmission. The transmission device 100 becomes overheated.

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

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

Here, the battery cell module 230 includes protection circuits such as overvoltage and overcurrent prevention circuits and temperature detection circuits, and also includes a charging management module that collects and processes information such as the charging state 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 detection unit 107 of each transmission block 110 detects which charging position the wireless power receiving device 200 is placed in and charges. The transmission block 110 where the wireless power receiving device 200 is not placed is maintained in the ready state, and the transmission block 110 where the wireless power receiving device 200 is placed receives wireless power on a certain primary coil 101. By checking whether the receiving device 200 is placed, the driving driver is switched so that the wireless power signal is driven in the primary coil 101 at the corresponding position, or both converters 103 are controlled to operate.

As described above, by converting the driving driver 105, the object detection unit 107, the converter 103, and the primary coil into a transmission block, maintenance becomes convenient, and standby power can be significantly reduced to increase power efficiency.

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

As described above, if you install two primary coils, you can charge two wireless power receiving devices at the same time. In this case, use a 5~10W class adapter (SMPS). If you install four primary coils, In this case, four wireless power receiving devices can be charged at the same time, and in this case, a 10~15W adapter (SMPS) is used.

In addition, if the primary coil 101 is separated from the main board, that is, the transmission block 110, the transmission control unit 120, and the temperature sensor 130 are installed on the main board, and one of the transmission blocks 110 If the primary coil 101 is installed separately from the main board, a space can be provided to minimize the magnetic field generated from the primary coil 101 affecting the board, and manufacturing costs can also be reduced.

Figure 3 is a flowchart showing a method of detecting foreign matter 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 matter detection operation is performed before initial charging (S200). As an example, the foreign matter detection operation before initial charging is shown in FIG. 6.

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

If no foreign matter is detected before initial charging (S205), when charging begins, a foreign matter detection operation is performed during charging (S210).

As an example, foreign substances can be detected by performing one-way communication during charging. As an example, the foreign matter detection operation using one-way communication during charging is shown in FIG. 7.

As another example, foreign substances can be detected by performing two-way communication during charging. As an example, the foreign matter detection operation using two-way communication during charging is shown in FIG. 8.

As another example, foreign matter may be detected by performing the one-way communication and the two-way communication simultaneously or independently during charging.

If a foreign object is detected during charging (S215), a power limiting operation in response to the foreign object detection is performed as in step S225.

If no foreign matter is detected during charging (S215), if a problem occurs in power transmission due to fine undetected foreign matter, the power is limited based on the temperature sensor 130 (or thermistor) to protect power transmission (e.g., Turn off the power) (S220). The temperature sensor may be attached to a receiving device or may be attached to a transmitting device.

Alternatively, even after the power limiting operation in response to foreign matter detection is performed in step S225, if a problem occurs in power transmission due to a fine undetected foreign matter, the power is limited based on the temperature sensor (or thermistor) to protect power transmission.

Figure 4 is a flowchart showing a method of detecting foreign matter 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 matter detection operation is performed before initial charging (S300).

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

If foreign substances are not detected before initial charging (S305), if there is a problem with power transmission due to fine undetected foreign substances, the power is limited based on the temperature sensor (or thermistor) to protect power transmission (e.g., power Hang up)(S310). The temperature sensor may be attached to a receiving device or may be attached to a transmitting device.

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

FIG. 5 is a flowchart showing a method of detecting foreign matter 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 begins, a foreign matter detection operation is performed during charging (S400).

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

If no foreign matter is detected during charging (S405), if there is a problem with power transmission due to fine foreign matter that has not been detected, the power is limited based on the temperature sensor (or thermistor) to protect power transmission (e.g., cut off power) )(S410). The temperature sensor may be attached to a receiving device or may be attached to a transmitting device.

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

Now, the operation of detecting foreign substances according to the present invention will be described separately before initial charging and after charging (e.g., using one-way communication or two-way communication).

One. Foreign matter detection operation before initial charging

FIG. 6 is a flowchart illustrating a method of detecting foreign matter 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 the ping phase, the wireless power transmission device performs digital ping, and at this time, the wireless power transmission device transmits a power signal at the operating point to the wireless power reception device (S500).

When receiving a power signal of the ping phase, the wireless power receiving device generates a signal strength packet indicating the received strength of the power signal and transmits it to the wireless power transmitting device (S505). Then, the wireless power receiving device generates an identification packet indicating a unique ID of the wireless power receiving device and configuration information of the wireless power receiving device, and transmits the identification packet and configuration information to the wireless power transmitting device (S510).

The wireless power receiving device measures the received power (S515). From this point on, the step of setting the initial voltage V _i is entered.

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

If it is charging in step S530, the wireless power receiving device compares the received power to the required power, generates a power control packet based on the result, and transmits it to the wireless power transmitting device (S535). If it is not charging in step S535, the wireless power receiving device determines whether the initial voltage V _i is in a hold state (S540). If the steady-state value of the initial voltage V _i is within the reference voltage range (for example, 7.0V to 10.5V), the initial setup of the wireless power receiving device is completed. As a result, the initial voltage _Vi is in a hold state, and the wireless power receiving device can enter the foreign matter detection phase.

If V _i is not in the hold state, the wireless power receiving device generates a power control packet and transmits it to the wireless power transmitting device as in the case of charging (S535). If V _i is in the hold state, the wireless power receiving device enters the foreign matter detection phase. Here, the wireless power receiving device generates a foreign matter status packet and transmits it to the wireless power transmitting device (S545).

The foreign matter status packet according to the present invention includes a preamble, header, message, and checksum. The preamble can consist of a minimum of 11 bits and a maximum of 25 bits, and the value of 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 object status packet and synchronize with 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 status packet may be '0x00'. In this case, the message may have its value set to 0, that is, '0x00'. As another example, the header value of the foreign matter status packet may be '0x05', which is the same as the header of the charge status packet. However, the value of the 1-byte message of the charging state packet is set to '0x00', thereby indicating that it is a foreign matter state packet. That is, the foreign matter status packet is included in the charging status packet.

The wireless power transmission device determines whether the received packet is a foreign object packet based on the value of the header or message of the received packet. And if it is determined that the foreign matter status packet has been received, the wireless power transmission device performs foreign matter detection (S550). The operation of checking the foreign matter status packet and 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

Figure 7 is an operation flowchart 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 the wireless power reception device (S600). At this time, the wireless power transmission device is in a charging standby state until the wireless power reception device is searched.

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 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 the current flowing in the primary coil, and the wireless power transmission device obtains a current measurement value from the current flowing in the primary coil (S610). The current measured by the wireless power transmission device may be alternating current. The current measurement value may be converted to a DC value suitable for recognition by a control unit in the wireless power transmission device. That is, the wireless power transmission device measures a relatively high alternating current flowing in the primary coil, and maps the measured high current to a current measurement value that is suitable for interpretation by the control unit, 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 performs foreign matter detection using any one or a combination of two or more of the following parameters, such as reference current I _ref , reference range (I _low ~ I _high ), reference AC signal, and foreign matter detection time t (S615 ). And parameters such as reference current I _ref , reference range (I _low to I _high ), reference AC signal, and foreign matter detection time t may be pre-stored in the wireless power transmission device as initial setting values. If a foreign substance is not detected, the wireless power transmission device continuously transmits power to the wireless power reception device (S620). Then, the wireless power transmission device obtains the current measurement value of the primary coil again at a time point t predetermined by the system or standard (S610), and can attempt to detect foreign substances based on this (S615).

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

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

Figure 8 is an operation flowchart 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 a transmitting device to a receiving device, the receiving device informs the transmitting device of the received power value, and if the power loss is greater than a predetermined standard value, it is determined to be FOD. It says what to do. For example, performing two-way communication means that if 7 to 10W of power is transmitted from the transmitting device to the receiving device and the receiving device receives 5W of power, the received power value '5W' is notified to the transmitting device, and the power loss is 2W. Since it is greater than the predetermined standard value of 1W, it is judged as FOD. Through this, FOD can be detected in the power transmission stage.

To describe the two-way communication in detail with reference to FIG. 8, the wireless power transmission device searches for the wireless power reception device (S700). At this time, the wireless power transmission device is in a charging standby state until the wireless power reception device is searched.

If the detected object is a wireless power receiver, the wireless power transmitter enters charging mode and transmits wireless power to the wireless power receiver (S705). In 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). As an example, the wireless power transmission device transmits a transmission power measurement report as an FSK signal to the wireless power reception device. 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). At this time, the wireless power transmission device may transmit the FSK signal at a constant cycle. This is because the wireless power receiving device may not know the transmission time of the FSK signal. The constant period may be a section in which a certain number of data signals are transmitted (eg, the ASK signal is constant).

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

The FSK signal switches or selects a certain range of variable frequencies (e.g., 140 or 140.3Khz) that converts one fixed power frequency (f ₀ , e.g., 145kHz) required by the receiving device. So, it refers to a signal that transmits 0 and 1 values. As another example, it refers to a signal that transmits a data signal containing 0 and 1 values using phase.

As an example, the wireless power transmission device may measure the power generated in the main coil according to the AC current signal, construct a transmission power measurement report indicating the measured generated power, and transmit it to the wireless power reception device. In this way, control information may be transmitted through a path from the wireless power transmission device to the wireless power reception device (for example, control information may be transmitted as an FSK signal), or through a path from the wireless power reception device to the wireless power transmission device. Two-way communication in 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 reception device.

The required power of the wireless power receiving device generates a duty cycle or voltage, and the duty cycle or voltage value is the power value of the wireless power transmitting device. That is, the power of the wireless power transmission device can be expressed as the voltage applied to the inverter, duty setting, and frequency.

In the step of transmitting power, the wireless power transmitter transmits a 'transmission power value' of a set value (eg, voltage, duty frequency) to the wireless power receiver using the FSK method.

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

The FSK signal may be transmitted at regular intervals (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 signal).

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

Next, the wireless power receiving device detects foreign matter based on the transmission power measurement report (S715). For example, the FSK signal including the received power value measured by the wireless power receiving device and the generated power measurement report is calculated, and if the difference value is greater than a predetermined reference value, it is determined to be FOD. As another example, the wireless power receiving device determines it to be FOD if 'received power-transmitted power' is greater than a predetermined reference value.

For example, the measured received power value may be information indicating whether the difference between the power indicated by the transmitted power measurement report and the required 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 required power is greater than 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 set to the threshold. If it is less than or equal to, it can be set to 'received power measurement result = 0'. 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 set. When it is less than the threshold, it may be set to 'received power measurement result = 0'. For example, let's say the threshold is 1W. As in the example above, 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 of 1W. In this case, the received 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 substance detection declaration.

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

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

Additionally, the ASK signal may include required power information of the wireless power reception device. Required power information refers to information that requires a wireless power transmission device to generate wireless power based on magnetic induction. The wireless power transmitter checks the required power information and sends a control signal to induce the power indicated by the required power information. This is information that causes it to occur. For example, when the required power information indicates 10W, the wireless power transmission device generates a control signal to transmit 10W.

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

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

Since it is impossible to simultaneously transmit and receive a data signal (eg, ASK signal or FSK signal), transmission or reception is performed sequentially. On the other hand, because power continues to be generated through the induced frequency, it is possible for the power signal and data signal to be transmitted simultaneously. Therefore, wireless power can be transmitted simultaneously or at any time, regardless of when the ASK signal and the FSK signal are transmitted and received.

According to steps S720 and S725, the ASK signal and wireless power can be transmitted and received multiple times.

When a certain period (750) has elapsed in step S710, the wireless power transmission device transmits a transmission power measurement report indicating the measured transmission power to the wireless power reception device (S730). As an example, the wireless power transmission device transmits a transmission power measurement report as an FSK signal to the wireless power reception device. 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 signal).

Meanwhile, if it is determined that a foreign substance has been detected in the wireless power reception device, the wireless power transmission device may take action to detect the foreign substance (not shown). For example, the wireless power transmission device may enter a blocking mode in which operation of the main coil is reduced or stopped. This prevents the parasitic load from generating heat, and the supply of inefficient induced power can be limited or stopped.

According to the wireless power transmission device capable of simultaneous multi-charging, which is an embodiment of the present invention having the above-described configuration, a plurality of wireless power reception devices can be charged simultaneously.

Moreover, by partitioning the wireless power transmission device into transmission blocks, initial standby power can be greatly reduced, efficiency in detecting foreign substances during charging can be 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, and the embodiments are all or part of each embodiment 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: driving driver
107: object detection unit
110: transmission block
120: Transmission control unit
130: Temperature sensor
200: wireless power receiving device
210: Secondary coil (receiving coil)
220: rectifier
230: battery
240: reception control unit
300: Adapter (SMPS)

Claims (8)

A plurality of transmission blocks comprising two or more primary coils; and
When a plurality of wireless power receiving devices are placed in a charging position, response signals from the primary coils corresponding to the charging positions are used to select a plurality of primary coils corresponding to the wireless power receiving devices, and the selected plurality of coils are selected. A wireless power transmission device capable of simultaneous multi-charging, including a transmission control unit that controls the transmission blocks to simultaneously transmit wireless power signals from the primary coil of.
According to claim 1,
The transport block is,
an object detection unit that transmits a response signal generated by the wireless power reception device to the transmission control unit in the primary coil;
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 sends a driving signal only to the primary coil detected by the object detection unit under control of the transmission control unit.
According to claim 1,
A wireless power transmission device capable of simultaneous multi-charging, further comprising an adapter that converts external alternating current power to direct current power and supplies power to the wireless power signal.
According to claim 3,
A wireless power transmission device capable of simultaneous multi-charging, wherein the adapter is installed to be replaceable according to the number of primary coils.
According to claim 1,
further comprising a temperature sensor,
The transmission control unit,
A wireless power transmission device capable of simultaneous multi-charging, which limits transmission of all wireless power signals if the temperature measured from the temperature sensor is greater than a reference value while the wireless power signals are simultaneously transmitted.
According to claim 1,
The transmission control unit,
A wireless power transmission device capable of simultaneous multi-charging, controlling the output of the wireless power signal based on the charging state information transmitted through the primary coil.
According to claim 5,
The transmission control unit,
A wireless power transmission device capable of simultaneous multi-charging, wherein when a signal strength packet signal for digital ping is received from all of the primary coils, a wireless power signal is controlled to be generated from all of the primary coils.
According to claim 7,
The transmission control unit,
After transmitting a wireless power signal to the primary coil in an alternating manner, charging status information from the wireless power receiving device is analyzed, and a primary coil whose current value rectified by the wireless power receiving device is equal to or greater than a reference value is identified, This 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, the wireless power signal is controlled to oscillate in all of the primary coils. A wireless power transmission device capable of simultaneous multi-charging.