KR102598645B1 - Wireless power transfer appratus - Google Patents

Abstract

The present invention relates to a wireless power transmission device. A wireless power transmission device according to an embodiment of the present invention includes a plurality of partially overlapping transmission coils, and wirelessly transmits power to a wireless power reception device through any one coil combination selected from the plurality of transmission coils. Generate the coil combination to include a power transmission unit and at least one transmission coil among the plurality of transmission coils, transmit a coil selection signal through the transmission coil included in the coil combination, and select the transmission coil. A control unit that receives a response signal to the coil selection signal through a control unit that selects an operating coil combination to be used for wireless power transmission among the coil combinations based on the response strength of the response signal and charging efficiency of the wireless power receiving device. Includes. Accordingly, in partially overlapping multi-coils, the highly efficient charging area can be expanded.

Description

Wireless power transmission device {WIRELESS POWER TRANSFER APPRATUS}

The present invention relates to a wireless power transmission device, and more specifically, to a wireless power transmission device that can expand the charging area of a wireless power receiving device and increase charging efficiency.

A method for supplying power to electronic devices, a terminal supply method that connects a physical cable or wire between a commercial power source and electronic devices, or a physical cable or wire as a method for supplying power to electronic devices. There is. In this terminal supply method, cables or wires take up a significant amount of space, are not easy to organize, and there is a risk of disconnection.

Recently, research on wireless power transmission methods has been discussed to solve these problems.

The wireless power transmission system may be comprised of a wireless power transmission device that supplies power through a single coil or multiple coils, and a wireless power reception device that receives power wirelessly supplied from the wireless power transmission device and uses the same.

However, the conventional energy transfer method using a single coil has a limited charging area, so there is a problem that it cannot be used for wireless power reception devices of various sizes.

In addition, the conventional energy transfer method using a multi-coil selects the coil to be used for charging only based on the strength of the response signal to the signal transmitted from the wireless power transmission device, so although charging efficiency is superior, the response strength is low and cannot be selected. There is a problem that the charging efficiency is reduced due to the appearance of the coil.

The purpose of the present invention is to provide a wireless power transmission device that can expand a highly efficient charging area in partially overlapping multi-coils.

In order to achieve the above object, a wireless power transmission device according to an embodiment of the present invention includes a plurality of partially overlapping transmitting coils, and receives wireless power through any one coil combination selected from the plurality of transmitting coils. Generating the coil combination to include a power transmitter that wirelessly transmits power to the device, and at least one transmitting coil among the plurality of transmitting coils, and sending a coil selection signal through the transmitting coil included in the coil combination. Transmitting and receiving a response signal to the coil selection signal through the transmitting coil, based on the response strength of the response signal and the charging efficiency of the wireless power receiving device, among the coil combinations, an operation to be used for wireless power transmission It includes a control unit that selects a coil combination.

In order to select an operating coil to be used for wireless power, the wireless power transmission device according to an embodiment of the present invention applies a weight that increases in proportion to charging efficiency to the response signal strength of the wireless power receiving device to select the coil, thereby charging. Even though efficiency is high, it can prevent cases where it is not selected as an operating coil.

Additionally, since the wireless power transmission device charges the wireless power reception device through a combination of coils rather than a single coil, charging time is reduced.

Additionally, since the wireless power transmission device charges the wireless power reception device through a plurality of transmission coils, the charging area is expanded compared to when a single coil is used.

Additionally, the user convenience of the wireless power transmission device can be increased due to the expansion of the charging area.

Additionally, since the plurality of transmitting coils in the wireless power transmission device are arranged to partially overlap to reduce dead zones, the wireless power reception device can be charged at any position on the charging surface.

In addition, the wireless power transmission device can be factory calibrated so that the transmission strength of each coil selection signal transmitted from a plurality of transmission coils is the same in terms of charging, and thus more accurately selects the operating coil combination. It becomes possible.

In addition, the wireless power transmission device sets the main coil and auxiliary coil in the operating coil based on the response signal strength, and communicates with the wireless power receiving device only through the main coil, so that wireless power is transmitted without signal interference by the auxiliary coil. It is possible to communicate stably with the receiving device.

Figure 1 is an example of an internal block diagram of a wireless power system according to an embodiment of the present invention.
FIG. 2 is an internal block diagram of a wireless power transmission device in the wireless power system of FIG. 1.
FIG. 3 is an internal block diagram of a wireless power reception device in the wireless power system of FIG. 1.
FIG. 4 is a diagram for explaining the structure of the power transmission unit of FIG. 2.
FIG. 5 is a perspective view showing the hierarchical structure of the power transmission unit of FIG. 4.
Figure 6 is a flowchart for explaining a wireless power transmission method according to an embodiment of the present invention.
Figure 7 is a flowchart for explaining a method of selecting an operating coil combination according to an embodiment of the present invention.
Figure 8 is a diagram for explaining a method of generating a coil combination.
FIG. 9 is a diagram showing an example of a coil selection signal according to the coil combination of FIG. 8.
FIG. 10 is a diagram for explaining the factory calibration level of the coil selection signal of FIG. 9.
FIG. 11 is a diagram for explaining a method of selecting the operating coil combination of FIG. 8.
FIG. 12 is a diagram for explaining a method of selecting the operating coil combination of FIG. 8.
FIG. 13 is a diagram for explaining a method of selecting the operating coil combination of FIG. 8.
Figure 14 is a flowchart for explaining a method of selecting an operating coil combination according to another embodiment of the present invention.
FIG. 15 is a diagram referred to in the description of FIG. 14.
Figure 16 is a flowchart for explaining a method of selecting an operating coil combination according to another embodiment of the present invention.
Figure 17 is a flowchart for explaining a method of selecting an operating coil combination according to another embodiment of the present invention.

Hereinafter, 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 simply given in consideration of the ease of writing this specification, and do not in themselves give any particularly important meaning or role. Accordingly, the terms “module” and “unit” may be used interchangeably.

Terms containing ordinal numbers, such as first, second, etc., may be used to describe various components, but the components are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another.

In this application, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the presence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Figure 1 is an example of an internal block diagram of a wireless power system according to an embodiment of the present invention.

When described with reference to the drawings, the wireless power system 10 may include a wireless power transmission device 100 that transmits power wirelessly and a wireless power reception device 200 that receives the wirelessly transmitted power.

The wireless power transmission device 100 can transmit power to the wireless power reception device 200 by changing the magnetic field of the transmitting coil 181 and using the magnetic induction phenomenon in which current is induced in the receiving coil 281. . At this time, the wireless power transmission device 100 and the wireless power reception device 200 may use the electromagnetic induction wireless charging method defined by the Wireless Power Consortium (WPC).

The wireless power transmission device 100 can charge the wireless power reception device 200 by transmitting power wirelessly.

Depending on the embodiment, one wireless power transmission device 100 may charge a plurality of wireless power reception devices 200. At this time, the wireless power transmission device 100 may distribute and transmit power to a plurality of wireless power reception devices 200 in a time-sharing manner, but is not limited to this. As another example, the wireless power transmission device 100 , power can be distributed and transmitted to a plurality of wireless power reception devices 200 using different frequency bands allocated to each wireless power reception device 200. The number of wireless power receiving devices 200 that can be connected to one wireless power transmitting device 100 is adaptive in consideration of the amount of power required for each wireless power receiving device 200, the amount of available power of the wireless power transmitting device 100, etc. can be decided.

In another embodiment, it is possible for a plurality of wireless power transmission devices 100 to charge at least one wireless power reception device 200. In this case, at least one wireless power reception device 200 may be simultaneously connected to a plurality of wireless power transmission devices 100 and may perform charging by simultaneously receiving power from the connected wireless power transmission devices 100. there is. At this time, the number of wireless power transmission devices 100 may be adaptively determined by considering the amount of power required for each wireless power reception device 200, the amount of available power of the wireless power transmission device 100, etc.

The wireless power reception device 200 may receive power transmitted from the wireless power transmission device 100.

For example, the wireless power receiving device 200 may be used in wearable devices such as mobile phones, laptop computers, smart watches, Personal Digital Assistants (PDAs), and Portable Multimedia (PMPs). Player), navigation, MP3 player, electric toothbrush, lighting device, remote control, but the present invention is not limited thereto, and any electronic device capable of charging a battery is sufficient.

The wireless power transmission device 100 and the wireless power reception device 200 can communicate in two directions. Depending on the embodiment, the wireless power transmission device 100 and the wireless power reception device 200 may perform one-way communication or half-duplex communication.

At this time, the communication method may be an in-band communication method using the same frequency band and/or an out-of-band communication method using different frequency bands. .

As an example, the information exchanged between the wireless power transmission device 100 and the wireless power reception device 200 includes each other's status information, power usage information, battery charging information, battery output voltage/current information, control information, etc. can do.

FIG. 2 is an internal block diagram of a wireless power transmission device in the wireless power system of FIG. 1.

When described with reference to the drawings, the wireless power transmission device 100 includes a converter 110 that converts commercial AC power 405 into DC power, a wireless power driver 170 that converts DC power into AC power, and A power transmission unit 180 that transmits power wirelessly using converted AC power may be provided.

In addition, the wireless power transmission device 100 includes a control unit 160 that controls the internal configuration of the wireless power transmission device 100 for power transfer and communication, and a wireless power reception device 200 using a predetermined communication method. ), a first communication unit 140 and a second communication unit that communicate with each other, a sensing unit 130 that senses the current flowing through the wireless power transmission device 100, the temperature of the power transmission unit 180, etc., and a wireless power transmission device It may further include a memory 120 that stores a control program for driving 100, etc.

The wireless power transmission device 100 operates by direct current power, and this direct current power can be supplied by a converter 110 that converts commercial alternating current power into direct current power.

The converter 110 can convert the commercial AC power 405 into DC power and output it. In the drawing, the commercial AC power source 405 is shown as a single-phase AC power source, but it may also be a three-phase AC power source. The internal structure of the converter 110 may also vary depending on the type of commercial AC power source 405.

Meanwhile, the converter 110 may be made of a diode or the like without a switching element, and may perform a rectification operation without a separate switching operation.

For example, in the case of a single-phase AC power source, four diodes can be used in a bridge form, and in the case of a three-phase AC power source, six diodes can be used in a bridge form.

Meanwhile, the converter 110 may be, for example, a half-bridge type converter in which two switching elements and four diodes are connected, and in the case of three-phase AC power, six switching elements and six diodes may be used. .

During wireless power transmission, when direct current power from the converter 110 is supplied to the wireless power driver 170, the control unit 160 controls the power driver 170 to wirelessly transmit power to the wireless power reception device 200. Power can be transmitted. At this time, the wireless power driver 170 can convert direct current power into alternating current power for wireless power transmission.

Specifically, the control unit 160 may include a PWM generator 160a that generates a PWM signal, and a driver 160b that generates and outputs a driving signal (Sic) based on the PWM signal.

The control unit 160 may determine the duty of the PWM signal based on the amount of power transmission, the current value flowing through the wireless power driver 170, etc. The PWM generator 160a may generate a PWM signal based on the duty of the PWM signal. The driver 160b may output a driving signal (Sic) for driving the wireless power driver 170 based on the PWM signal.

The wireless power driver 170 may include at least one switching element (not shown) for converting direct current power to alternating current power. For example, when the switching device is IBGT, a gate driving signal may be output from the driver 160b and input to the gate terminal of the switching device. Additionally, the switching element may perform a switching operation according to the gate driving signal. Direct current power can be converted into alternating current power by the switching operation of the switching element and output to the power transmission unit 180.

Meanwhile, depending on the embodiment, the wireless power driver 170 may be included in the control unit 160.

The power transmission unit 180 may include a plurality of transmission coils 181 to 184 (hereinafter referred to as 181 if there is no need for distinction). The plurality of transmitting coils 181 may partially overlap.

The power transmission unit 180 may wirelessly transmit power to the wireless power reception device 200 through any one coil combination selected from the plurality of transmission coils 181.

The power transmission unit 180 may further include a shielding material (190 in FIG. 4) disposed on one side of the plurality of transmission coils 181 to shield a leaked magnetic field.

Meanwhile, the structure of the power transmission unit 180 will be examined in more detail in FIG. 4 and below.

The first communication unit 140 may communicate with the wireless power reception device 200 using a first communication method. The first communication unit 140 processes status information, power control information, etc. of the wireless power transmitter 200 into a predetermined signal and transmits it to the wireless power receiver 200, status information of the wireless power receiver 200, Power usage information, charging efficiency information, etc. can be received, processed as a predetermined signal, and then transmitted to the control unit 160.

The second communication unit 150 may communicate with the wireless power reception device 200 using a second communication method that is different from the first communication method. The second communication unit 140 also processes status information, power control information, etc. of the wireless power transmission device 200 into a predetermined signal and transmits it to the wireless power receiving device 200, status information of the wireless power receiving device 200, Power usage information, charging efficiency information, etc. can be received, processed as a predetermined signal, and then transmitted to the control unit 160.

The first communication unit 140 and the second communication unit 150 are for modulating/demodulating a data signal transmitted from the wireless power transmission device 100 and a data signal received from the wireless power reception device 200. It may further include a disguise (not shown).

Additionally, the first communication unit 140 and the second communication unit 150 may further include a filter unit (not shown) that filters the data signal from the wireless power reception device 200. At this time, the filter unit (not shown) may be provided with a band pass filter (BPF).

Meanwhile, the first communication method may be an in-band communication method using the same frequency band as the wireless power receiving device 200, and the second communication method may be a different from the wireless power receiving device 200. It may be an out-of-band communication method using a frequency band.

The wireless power transmission device 100 may change the communication method based on the power information of the wireless power reception device 200.

Meanwhile, changes to the communication method of the wireless power transmission device 100 will be examined in more detail in FIG. 17.

The sensing unit 130 may measure voltage, current, etc. of power delivered to the wireless power receiving device 200 and provide the measurements to the control unit 160. In addition, the sensing unit 130 measures the temperature of the plurality of transmission coils 181 or the shielding material 190 to determine whether overheating of the wireless power transmission device 100 has occurred, and sends the measurement result to the control unit 160. It may also be provided to .

At this time, the control unit 160 may stop wireless power transmission to the wireless power reception device 200 based on voltage, current, and temperature information measured by the sensing unit 130.

The memory 120 may store a program for operating the power transmission device 100.

Additionally, the memory 120 may store the transmission intensity of each object detection signal transmitted from a plurality of transmission coils in order to detect an object on the charging surface.

Additionally, the memory 120 may store the transmission intensity of each coil selection signal transmitted from a plurality of transmission coils.

At this time, the transmission intensity of the object detection signal and the transmission intensity of the coil selection signal may be factory calibrated signals.

Specifically, the plurality of transmitting coils 181 to 184 of the present invention partially overlap to form a layer as shown in FIG. 4, so when each transmitting coil transmits an object detection signal and a coil selection signal with the same transmission intensity. , the strength of each object detection signal and coil selection signal on the charging surface where the wireless power receiving device 200 is placed may be different.

This difference in intensity between the object detection signal and the coil selection signal on the charging surface may cause an error in the combination of object detection and operation coil.

In order to solve this problem, the present invention can set the transmission intensity of the object detection signal and the transmission intensity of the coil selection signal by compensating for the distance between each transmitting coil and the charging surface on which the wireless power receiving device 200 is placed. there is.

For example, the longer the distance between the charging surface and the transmitting coil, the greater the transmission strength of the object detection signal and the greater the transmission strength of the coil selection signal.

Accordingly, the strength of each object detection signal on the charging surface where the wireless power receiving device 200 is placed may all be the same. Additionally, the strength of each coil selection signal on the charging surface may be the same.

Meanwhile, the transmission intensity of the compensated object detection signal and the transmission intensity of the coil selection signal may be stored in the memory 120 as factory calibration values.

The control unit 160 may control the overall operation of the wireless power transmission device 100.

The control unit 160 may generate a coil combination such that at least one transmission coil is included among the plurality of transmission coils 181.

Additionally, the control unit 160 may transmit a coil selection signal and receive a response signal for coil selection through a transmitting coil included in the coil combination.

Additionally, the control unit 160 may select an operating coil combination to be used for wireless power among coil combinations based on the strength of the response signal and the charging efficiency of the wireless power receiving device 200.

Meanwhile, the control unit 160 may transmit an object detection signal through a plurality of transmission coils 181 and calculate an invalid transmission coil based on the amount of current change for the object detection signal.

Additionally, the control unit 160 may generate a combination of effective coils excluding invalid transmission coils.

Meanwhile, the control unit 160 calculates the power of the wireless power reception device 200 based on the unique information of the wireless power reception device 200 received through the power transmission unit 180, and receives the calculated wireless power. Based on the power of the device 200, the number of operating coils may be calculated.

Additionally, the control unit 160 may generate a coil combination according to the number of operating coils.

Meanwhile, the operating coil combination selection method is shown in more detail in FIGS. 7 to 13, the effective coil combination is shown in FIGS. 14 to 15, and the coil combination generation according to the power of the wireless power receiving device 200 is shown in more detail in FIG. 17. Take a look.

FIG. 3 is an internal block diagram of a wireless power reception device in the wireless power system of FIG. 1.

When described with reference to the drawings, the wireless power receiving device 200 includes a power receiving unit 280 that receives wireless power from the wireless power transmitting device 100, a rectifying unit 210 that rectifies the received wireless power, and a rectifying unit 210 that rectifies the received wireless power. It may include a switching regulator 220 that stabilizes the wireless power, and a switching regulator control unit 230 that controls the switching regulator 220 to output operating power to the load.

Additionally, the wireless power reception device 200 may further include a first communication unit 240 and a second communication unit 150 for communicating with the wireless power transmission device 100.

The power receiver 280 may receive wireless power transmitted from the power transmitter 180. For this purpose, the power receiving unit 280 may be provided with a receiving coil 281.

The receiving coil 281 may generate an induced electromotive force by a magnetic field generated by any one of the plurality of transmitting coils 181 to 184. Wireless power generated by induced electromotive force passes through a rectifier 210 and a switching regulator 220, which will be described later, and is directly supplied to a load using wireless power. Or, if the load is a battery, the power will be used to charge the battery. You can.

The receiving coil 281 may be formed as a thin film-type conductive pattern on a printed circuit board (PCB). The receiving coil 281 may be printed on a receiving pad (not shown) in a closed loop shape. The polarity of the receiving coil 281 may be wound to have polarity in the same direction.

The rectifier 210 may rectify the wireless power received through the receiving coil 281 when receiving wireless power from the wireless power transmission device 100. The rectifier 210 may include at least one diode element (not shown).

The switching regulator 220 can output the rectified wireless power as charging power (v) supplied to the battery under the control of the switching regulator control unit 230.

The switching regulator control unit 230 may control the charging power (v) to be output by applying a regulator control signal (Src) to the switching regulator.

Meanwhile, the switching regulator 220 may perform DC-DC conversion according to the regulator control signal (Src) of the switching regulator control unit 230 to adjust the output voltage. The switching regulator 220 may control the output voltage based on the regulator control signal (Src) and output charging power (v) having a voltage of a specified magnitude.

Meanwhile, the wireless power receiving device 200 does not include a separate microprocessor, and when the rectified charging power (v) is output at a voltage of a predetermined level by the switching regulator, the switching regulator control unit 230 performs switching. The regulator can be controlled. When the wireless power receiving device 200 does not include a microprocessor, the hardware configuration is simplified and power consumption is reduced.

FIG. 4 is a diagram for explaining the structure of the power transmission unit of FIG. 2, and FIG. 5 is a perspective view showing the hierarchical structure of the power transmission unit of FIG. 4.

When described with reference to the drawings, the power transmission unit 180 according to an embodiment of the present invention may include first to fourth transmission coils 181 to 184.

As the power transmission unit 180 is provided with the first to fourth transmission coils 181 to 184 rather than a single large transmission coil, the degree of freedom of the charging surface is improved and the stray magnetic field of the large coil is reduced. It is possible to prevent a decrease in power efficiency due to fields).

The first to fourth transmitting coils 181 to 184 may be arranged with some areas overlapping with each other. Specifically, as shown in FIG. 4, the first transmission coil 181 partially overlaps the second transmission coil 182, and the second transmission coil 182 overlaps the third transmission coil 183. Some areas may overlap, and some areas of the third transmission coil 183 may overlap with the fourth transmission coil 184.

The overlapping area of the first to fourth transmission coils 181 to 184 may be set so that the dead zone, which is an unchargeable area, is minimized. Specifically, the overlapping area of the first to fourth transmission coils 181 to 184 may be set so that the dead zone at the center of the charging area is minimized.

The first to fourth transmitting coils 181 to 184 may be manufactured with preset outer length (ho), inner length (hi), outer width (wo), inner width (wi), thickness, and number of turns. Additionally, the outer length (ho), inner length (hi), outer width (wo), and inner width (wi) of the first to fourth transmission coils 181 to 184 may be the same.

Meanwhile, since the fourth transmitting coil 184 is disposed closest to the wireless power receiving device 200, the inductance of the fourth transmitting coil 184 is the inductance of the first to third transmitting coils 181 to 183. It can be set smaller. This is to keep the power transmission amount or power efficiency of the surface of the power transmission unit 180 constant.

The first to fourth transmitting coils 181 to 184 may be disposed on the shielding material 190. The shielding material 190 includes ferrite made of one or a combination of two or more elements selected from the group consisting of cobalt (Co), iron (Fe), nickel (Ni), boron (B), silicon (Si), etc. can do. The shielding material 190 is disposed on one side of the transmission coil to shield the leaking magnetic field and maximize the directionality of the magnetic field.

The shielding material 190 may be formed to have an area larger than the area where the first to fourth transmission coils 181 to 184 are disposed. For example, as shown in FIGS. 4 and 5, the shielding material 190 may be formed to extend at intervals a1 from the horizontal outer side of the first to fourth transmission coils 181 to 184. Additionally, the shielding material 190 may be formed to extend at intervals a1 from the vertical outer side of the first to fourth transmission coils 181 to 184.

By forming the shielding material 190 to be larger than the outer length of the first to fourth transmission coils 181 to 184, the leakage magnetic field can be reduced and the directionality of the magnetic field can be maximized.

Meanwhile, since the first to fourth transmitting coils 181 to 184 are arranged with some areas overlapping with each other, a lifting phenomenon may occur in areas that do not overlap. For example, in FIG. 5, since only a portion of the first transmission coil 181 and the second transmission coil 182 overlap each other, a separation distance of d1 may be generated in the non-overlapping region.

Due to this separation distance, the leakage magnetic field of the second transmission coil 182 may not be shielded, so the transmission efficiency of the wireless power transmission device 100 may be reduced and the direction of the magnetic field may be dispersed. Additionally, due to this separation distance, the wireless power transmission device 100 may be easily damaged by external shock.

In order to solve this problem, the present invention can be formed by forming the first to fourth transmission coils 181 to 184 and the shielding material 190 in layers.

More specifically, a base shielding material 191 may be disposed on the first layer ly1 of the power transmission unit 180.

The first transmitting coil 181 and the first shielding material 192 may be disposed on the second layer ly2, which is above the basic shielding material 191.

A second transmission coil 182 that partially overlaps the first transmission coil 181 may be disposed on the third layer ly3 above the first transmission coil 181. At this time, the first shielding material 192 disposed on the second layer ly2 prevents the lifting phenomenon caused by the overlapping structure of the first transmission coil 181 and the second transmission coil 182.

By the same logic, not only the second transmission coil 182 but also the second shielding material 193 may be disposed in the third layer ly3 of the power transmission unit 180.

A third transmission coil 183 that partially overlaps the second transmission coil 182 may be disposed on the fourth layer ly4 above the second transmission coil 182. At this time, the second shielding material 193 disposed on the third layer ly3 prevents the lifting phenomenon caused by the overlapping structure of the second transmission coil 182 and the third transmission coil 183.

In addition, in the fourth layer (ly4) of the power transmission unit 180, not only the third transmission coil 183 but also the third shielding material 194 may be disposed, and the third shielding material 194 may be disposed in the third transmission coil 183. The lifting phenomenon caused by the overlapping structure of the coil 183 and the fourth transmission coil 184 can be prevented.

In addition, the first to fourth transmitting coils 181 to 184 must be adhered to the shielding material 190 (including the basic shielding material 191 and the first to third shielding materials 192 to 194) without any lifting phenomenon. Therefore, it is preferable that the thickness (tkf) of the shielding material is the same as the thickness (tkc) of the first to fourth transmitting coils 181 to 184.

Meanwhile, in FIG. 5, each layer of the power transmission unit 180 is shown as being spaced apart, but this is for convenience of explanation, and each layer of the power transmission unit 180 may be in close contact with each other.

As the power transmission unit 180 is disposed as shown in FIG. 5, the lifting phenomenon of the first to fourth transmission coils 181 to 184, which partially overlap, is prevented, and the first to fourth transmission coils 181 to 184 are prevented from external shock. Separation of the coils 181 to 184 can be prevented.

In addition, since the shielding material 190 is disposed on one side of each transmission coil, leakage magnetic fields are shielded, the direction of the magnetic field is more concentrated, and transmission efficiency can be increased.

Additionally, as the shielding material 190 is disposed between each transmitting coil, heat generated from the multi-coil can be more easily reduced.

Meanwhile, the first to fourth transmission coils 181 to 184 may be accommodated in a case not shown for convenience of explanation. The wireless power receiving device 200 may be placed on one side of the case. When the wireless power receiving device 200 is placed on one side of the case, the power transmitter 180 wirelessly transmits power to charge the wireless power receiving device 200, so that the wireless power receiving device 200 One side of the case on which it is placed can be called the charging surface. Additionally, the charging surface and the interface surface can be used interchangeably.

Figure 6 is a flowchart for explaining a wireless power transmission method according to an embodiment of the present invention.

When described with reference to the drawings, wireless power transmission includes a selection phase (S610), a ping phase (S620), an identification and configuration phase (S630), and a handover phase (S640). ), negotiation phase (S650), calibration phase (S660), power transfer phase (S670), and re-negotiation phase (re-negotiation phase, S680).

First, in the selection step (S610), the wireless power transmission device 100 may detect whether objects exist within the detection area.

The wireless power transmission device 100 is located in the charging area based on the power change in the object detection signal (for example, the current change in the transmission coil) in order to detect whether objects exist in the detection area. It is possible to detect whether an object exists. At this time, the object detection signal may be a very short pulse analog ping (AP) signal. The wireless power transmission device 100 may transmit an analog ping (AP) signal at a predetermined period until an object is detected on the charging surface.

When the wireless power transmission device 100 is provided with a plurality of transmission coils 181, the wireless power transmission device 100 transmits object detection signals in a predetermined order through the plurality of transmission coils 181, respectively. Based on the amount of current change in the transmission coil in response to the object detection signal, it is possible to detect whether an object exists in the charging area.

Specifically, when the amount of current change is greater than or equal to a preset amount of current change, the wireless power transmission device 100 may calculate that an object exists in the charging area corresponding to the corresponding transmission coil. At this time, the corresponding transmission coil may be called an effective transmission coil used in an effective coil combination described later.

When the amount of current change is less than a preset amount of current change, the wireless power transmission device 100 may calculate that an object does not exist in the charging area corresponding to the corresponding transmission coil. At this time, the corresponding transmission coil may be called an invalid transmission coil that is not used in the effective coil combination.

Next, when the wireless power transmission device 100 is provided with a plurality of transmission coils 181, the wireless power transmission device 100 may select a combination of operating coils to be used for wireless power in the selection step (S610).

Specifically, the wireless power transmission device 100 may generate a coil combination such that at least one transmission coil is included among the plurality of transmission coils 181 in the selection step (S610).

Additionally, the wireless power transmission device 100 may transmit a coil selection signal and receive a response signal to the coil selection signal through a transmission coil included in the coil combination.

Additionally, the wireless power transmission device 100 may select a combination of operating coils to be used for wireless power based on the strength of the response signal and the charging efficiency of the wireless power reception device.

At this time, the coil selection signal may be a digital ping (DP) signal. Meanwhile, the digital ping (DP) signal output in the selection step (S610) is called Coil Selection Digital Ping (CSDP) in order to distinguish it from the digital ping (DP) signal output in the ping step (S620), which will be described later. ) can be named a signal.

The transmission intensity of the coil selection digital ping signal (CSDP) can be set by compensating for the distance between each transmitting coil and the charging surface on which the wireless power receiving device 200 is placed.

The coil selection digital ping signal (CSDP) may have characteristics such as frequency and transmission intensity different from the digital ping (DP) signal in the ping step (S620). For example, the transmission intensity of the coil selection digital ping signal (CSDP) is set to be lower than that of the digital ping (DP) signal, thereby reducing power consumption of the wireless power transmission device 100.

The coil selection digital ping signal (CSDP) may be a specialized signal for efficient coil combination selection.

For example, the wireless power transmission device 100 may transmit a digital ping signal (CSDP) and receive unique information of the wireless power reception device 200. The wireless power transmission device 100 may calculate the power of the wireless power reception device 200 based on unique information. The wireless power transmission device 100 may calculate the number of operating coils for efficient coil combination in consideration of the power of the wireless power receiving device 200 and generate a coil combination according to the calculated number of operating coils.

Next, in the selection step (S610), the wireless power transmission device 100 uses the quality factor (Q factor) and/or The resonance frequency (fo) can be measured.

The wireless power transmission device 100 may calculate whether a foreign substance exists in the charging area based on the amount of change in the quality factor (Q factor) and/or the resonance frequency (fo) in the selection step (S610).

Alternatively, the wireless power transmission device 100 calculates whether a foreign substance exists in the charging area based on the amount of change in the quality factor (Q factor) and/or the resonance frequency (fo) in the negotiation step (S650) to be described later. can do.

Foreign substances may be metallic objects including coins, keys, etc., and such foreign substances may be named FO (Foreign Object).

Meanwhile, the detection area may mean an area where the wireless power transmission device 100 can transmit power. Alternatively, the sensing area may mean a charging area where the wireless power receiving device 200 is charged, a charging surface, or an active area of the interface surface.

In the selection step (S610), the wireless power transmission device 100 may continuously detect the placement or removal of an object within the detection area. Additionally, in the selection step (S610), when the wireless power transmission device 100 detects an object within the detection area, it may transition to the ping step (S620).

When the wireless power transmission device 100 detects an object, the wireless power transmission device 100 wakes the wireless power reception device 200 in the ping step (S620) and detects the object. A receiving device detection signal may be transmitted to identify whether the (object) is the wireless power receiving device 200. At this time, the receiving device detection signal may be a digital ping (DP) signal.

The wireless power reception device 200 may modulate a digital ping (DP) signal and transmit the modulated digital ping (DP) signal to the wireless power transmission device 100.

The wireless power transmission device 100 can demodulate the modulated digital ping (DP) signal and obtain detection data in digital form corresponding to a response to the receiving device detection signal from the demodulated digital ping (DP) signal. there is.

The wireless power transmission device 100 can recognize the wireless power reception device 200 that is the target of power transmission from digital sensing data.

For example, the sensed data may include information about the degree of inductive coupling between the wireless power transmission device 100 and the wireless power reception device 200. The wireless power transmission device 100 may identify the wireless power reception device 200 based on the degree of inductive coupling between the wireless power transmission device 100 and the wireless power reception device 200.

Meanwhile, when the wireless power transmission device 100 is provided with a plurality of transmission coils 181, transmission of the receiving device detection signal and reception of the detection data in the ping step (S620) described above are performed in a selection step (S610). It can be performed through a combination of operating coils selected from .

When the wireless power transmission device 100 identifies the wireless power reception device 200 in the ping step (S620), the wireless power transmission device 100 may transition to the identification and configuration step (S630).

Alternatively, if the wireless power transmission device 100 does not receive sensing data in digital form in the ping step (S620), it may transition back to the selection step (S610).

In the identification and configuration step (S630), the wireless power transmission device 100 may receive identification information, power information, etc. transmitted by the wireless power reception device 200 and control the power to be transmitted efficiently.

First, in the identification and configuration step (S630), the wireless power reception device 200 may transmit identification data.

The identification data may include version information of the wireless power transmission protocol, manufacturer information of the wireless power reception device 200, basic device identifier information, and information indicating the presence or absence of an extended device identifier.

Additionally, in the identification and configuration step (S630), the wireless power reception device 200 may transmit power data.

The power data may include information about the maximum power of the wireless power reception device 200, information about the remaining power, power class information, etc.

The wireless power transmission device 100 may identify the wireless power reception device 200 and obtain power information of the wireless power reception device 200 based on the identification data and power data.

When the wireless power transmission device 100 identifies the wireless power reception device 200 and obtains power information of the wireless power reception device 200, the wireless power transmission device 100 may transition to the handover step (S630).

Alternatively, if the wireless power transmission device 100 does not receive identification data and/or power data in the identification and configuration step (S630), it may transition to the selection step (S610).

The wireless power transmission device 100 may calculate whether to change the communication method with the wireless power reception device 200 in the handover step (S640).

Specifically, the wireless power transmission device 100 performs a selection step (S610), a ping step (S620), or identification and configuration while communicating with the wireless power reception device 200 using an in-band communication method. In step S630, whether to maintain in-band communication or out-of-band communication is determined based on the power information of the wireless power receiving device 200 obtained in at least one step. You can calculate whether to change the communication method or not.

Meanwhile, the wireless power transmission device 100 determines whether entry into the negotiation step (S650) is necessary based on the negotiation field value received in the identification and configuration step (S630) or the handover step (S640). It can be calculated.

If negotiation is necessary as a result of the calculation, the wireless power transmission device 100 may transition to the negotiation step (S650) and perform a foreign object detection (FOD) procedure.

Additionally, if negotiation is unnecessary as a result of the calculation, the wireless power transmission device 100 may immediately transition to the power transmission step (S670).

The wireless power transmission device 100 detects foreign matter (FO) based on the received quality factor (Q factor) information and/or resonance frequency (fo) information in the selection step (S610) or negotiation step (S650). can do.

For example, when the wireless power transmission device 100 is in a normal state, it stores the reference quality factor (Q factor) and/or the reference resonance frequency (fo), and stores the currently received quality factor (Q factor) and/or By comparing the resonance frequency (fo) with the reference quality factor (Q factor) and/or the reference resonance frequency (fo), it is possible to calculate whether foreign matter exists in the charging area. At this time, the normal state may mean a case where only the wireless power receiving device 200 exists in the charging area without any foreign matter.

If a foreign substance is not detected, the wireless power transmission device 100 may go through the correction step (S660) and transition to the power transmission step (S670).

Alternatively, when a foreign substance is detected, the wireless power transmission device 100 may transition to the selection step (S610) without performing power transmission.

In the correction step (S660), the wireless power transmission device 100 may calculate power loss based on the difference between the transmission power of the wireless power transmission device 100 and the received power of the wireless power reception device 200. .

In the power transmission step (S670), the wireless power transmission device 100 may transmit power to the wireless power reception device 200.

In the power transmission step (S670), while transmitting power, the wireless power transmission device 100 receives power control information from the wireless power reception device 200 and, in response to the received power control information, transmits power to the transmission coil. The characteristics of the applied power can be adjusted.

For example, the power control information may include control error data, and the wireless power transmission device 100 may increase or decrease the power applied to the transmission coil based on the control error data.

In the power transmission step (S670), the wireless power transmission device 100 receives unwanted data (unexpected data), does not receive desired data, for example, power control information, for a preset time (time out), if a violation of the preset power transfer contract occurs (power transfer contract violation), or if charging is completed, the process may proceed to the selection step (S610).

Additionally, in the power transmission step (S670), the wireless power transmission device 100 needs to reconfigure the power transmission negotiation according to a change in the state of the wireless power transmission device 100 or the wireless power reception device 200. , it is possible to transition to the renegotiation stage (S680). At this time, when the renegotiation is normally completed, the wireless power transmission device 100 may return to the power transmission step (S670).

Meanwhile, renegotiation may be set based on status information of the wireless power transmission device 100 and the wireless power reception device 200. For example, the status information of the wireless power transmission device 100 may include information about the maximum amount of transmission that can be transmitted, information about the maximum number of wireless power reception devices 200 that can be accommodated, etc. Additionally, the status information of the wireless power receiving device 200 may include information about required power, etc.

FIG. 7 is a flowchart for explaining a method for selecting an operating coil combination according to an embodiment of the present invention, FIG. 8 is a diagram for explaining a method for generating a coil combination, and FIG. 9 is a coil combination of FIG. 8 It is a diagram showing an example of a coil selection signal according to , FIG. 10 is a diagram for explaining the factory calibration level of the coil selection signal of FIG. 9, and FIGS. 11 to 13 are diagrams showing the operating coil of FIG. 8. This diagram is intended to explain how to select a combination.

First, the control unit 160 may generate a coil combination to include at least one transmitting coil among the plurality of transmitting coils 181 to 184 (S710).

Referring to FIG. 8, in the basic mode, the control unit 160 selects one (single) or two (dual) transmission coils among the first to fourth transmission coils 181 to 184 to select a coil combination. can be created.

When generating a coil combination by selecting one transmitting coil in the basic mode, the control unit 160 selects the first transmitting coil 181 among the first to fourth transmitting coils 181 to 184 to generate the first coil. Combinations can be created. In the same way, the control unit 160 selects the second transmission coil 182 to select the second coil combination, the third transmission coil 183 to select the third coil combination, and the fourth transmission coil 184 to select the second coil combination. 4 coil combinations can be created.

Meanwhile, in the basic mode, when selecting one transmitting coil and creating a coil combination, the control unit 160 may set the selected one transmitting coil as the main transmitting coil to perform wireless power transmission and communication.

On the other hand, when the control unit 160 selects two transmission coils among the first to fourth transmission coils 181 to 184 and creates a coil combination, any one transmission coil is used to perform wireless power transmission and communication. It can be set as the main transmission coil to be used, and the remaining transmission coils can be set as auxiliary transmission coils to assist in wireless power transmission.

Therefore, when creating a coil combination by selecting two transmitting coils in the basic mode, the control unit 160 selects the first transmitting coil 181 and the second transmitting coil 182, but selects the first transmitting coil 181 ) is set as the main transmission coil and the second transmission coil 182 is set as the auxiliary transmission coil, the fifth coil combination, the first transmission coil 181 is set as the auxiliary transmission coil, and the second transmission coil 182 is set as the main transmission coil. A sixth coil combination set as a transmission coil can be created.

In the same way, the control unit 160 selects the first transmission coil 181 and the fourth transmission coil 184, sets the first transmission coil 181 as the main transmission coil, and sets the fourth transmission coil 184 as the main transmission coil. A seventh coil combination is set as the auxiliary transmission coil, and an eighth coil combination is set in which the first transmission coil 181 is set as the auxiliary transmission coil and the fourth transmission coil 184 is set as the main transmission coil. .

In addition, the control unit 160 selects the second transmission coil 182 and the third transmission coil 183, sets the second transmission coil 182 as the main transmission coil, and sets the third transmission coil 183 as the main transmission coil. A ninth coil combination set as the auxiliary transmission coil, a 10th coil combination set with the second transmission coil 182 as the auxiliary transmission coil, and the third transmission coil 183 as the main transmission coil can be created.

In addition, the control unit 160 selects the third transmission coil 183 and the fourth transmission coil 184, sets the third transmission coil 183 as the main transmission coil, and sets the fourth transmission coil 184 as the main transmission coil. An 11th coil combination set as the auxiliary transmission coil, a 12th coil combination set with the third transmission coil 183 set as the auxiliary transmission coil, and the fourth transmission coil 184 set as the main transmission coil can be created.

Meanwhile, when the control unit 160 selects two coils among the first to fourth transmitting coils 181 to 184 in the basic mode to generate a coil combination, the receiving coil 281 is placed on the charging surface. Coil combinations can be created considering the position of the coil.

For example, in Figure 8, the receiving coil 281 is placed only on the first transmitting coil 181 and the third transmitting coil 183, or only on the second transmitting coil 182 and the fourth transmitting coil 184. Since there is no case, the combination of the first to twelfth coils includes the combination of the first transmission coil 181 and the third transmission coil 183 and the combination of the second transmission coil 182 and the fourth transmission coil 184. I can't.

Ultimately, when the control unit 160 selects two coils among the first to fourth transmission coils 181 to 184 in the basic mode to generate a coil combination, the coil combination can be generated only from the transmission coils that are adjacent to each other. You can.

Meanwhile, the control unit 160 selects one or two coils among the first to fourth transmission coils 181 to 184 to create a coil combination is limited to the basic mode, and the number of coils included in the coil combination is , may vary depending on the power of the wireless power receiving device 200 (proportional to the size of the receiving coil).

For example, as shown in FIG. 13, when the power of the wireless power receiving device 200 is large, the control unit 160 selects all of the first to fourth transmission coils 181 to 184 to generate a coil combination. can do.

Next, the control unit 160 may transmit a coil selection signal through the transmitting coil included in the coil combination (S730).

Specifically, the control unit 160 may transmit a coil selection signal based on a predefined order, as shown at 910 in FIG. 9.

Meanwhile, as shown in FIG. 8, the total number of coil combinations generated from the first to fourth transmission coils 181 to 184 may be 12, and the control unit 160 may send a coil selection signal for each coil combination to a total of 12. It can be transmitted once. At this time, the coil selection signal may be a digital ping (DP) signal.

Meanwhile, as shown in FIGS. 4 and 5, the first to fourth transmission coils 181 to 184 partially overlap to form a layer, so each transmission coil transmits a coil selection signal with the same transmission intensity. In this case, the strength of each coil selection signal on the charging surface where the wireless power receiving device 200 is placed may be different.

For example, depending on the distance between each transmitting coil and the charging surface where the wireless power receiving device 200 is placed, the transmission voltage (Vrail) of the coil selection signal and the receiving voltage (Vrect) at the charging surface are shown in FIG. 10 and They can appear together.

In FIG. 10, 1010 is a graph of the change in the reception voltage (Vrect) with respect to the transmission voltage (Vrail) of the first transmission coil 181, and 1020 is a graph of the change in reception voltage (Vrail) with respect to the transmission voltage (Vrail) of the second transmission coil 182. It is a graph of the change in voltage (Vrect), 1030 is a graph of the change of the reception voltage (Vrect) with respect to the transmission voltage (Vrail) of the third transmission coil 183, and 1040 is a graph of the change of the transmission voltage (Vrail) of the fourth transmission coil 184. ) It may be a graph of changes in reception voltage (Vrect).

As shown in Figure 10, even when the first to fourth transmitting coils 181 to 184 transmit the coil selection signal at the same intensity of 7.6V, the reception voltage (Vrect) on the charging side ranges from 9V to 10.3V. can be detected.

This difference in the strength of the coil selection signal on the charging surface may cause an error in the operation coil combination, which will be described later.

To solve this problem, the memory 120 stores the transmission intensity of each coil selection signal transmitted from the first to fourth transmission coils 181 to 184, and the transmission intensity is, in terms of charging, respectively. It can be set by compensating for the distance between each transmitting coil and the charging surface on which the wireless power receiving device 200 is placed so that the strengths of the coil selection signals are all the same.

Meanwhile, the control unit 160 may transmit a digital ping signal at the digital ping (DP) level of the main transmission coil included in the coil combination.

Next, the control unit 160 may receive a response signal to the coil selection signal through the transmitting coil included in the coil combination (S750).

Meanwhile, since the coil selection signal is a digital ping (DP) signal, the wireless power reception device 200 can transmit a data packet to the wireless power transmission device 100.

The data packet may include unique information of the wireless power reception device 200, charging efficiency information, etc.

The unique information may include product information of the wireless power receiving device 200, particularly power consumption information.

Additionally, the charging efficiency information may include supply power information supplied to a load provided in the wireless power reception device 200 and information on the load's required power.

Next, the control unit 160 may calculate the response strength of the response signal to the coil selection signal and the charging efficiency of the wireless power reception device 200 (S770).

Specifically, the control unit 160 may calculate the response strength of the response signal to the coil selection signal. For example, response strength can be expressed as voltage.

In addition, the control unit 160 controls the wireless power reception device 200 based on the difference or ratio between the power supplied to the load (e.g., battery) provided in the wireless power reception device 200 and the required power of the load. Charging efficiency can be calculated.

As described above, the supply power supplied to the load and the required power of the load can be provided from a response signal received from the wireless power reception device 200 in step S750.

Meanwhile, the charging efficiency of wireless power transfer by inductive coupling has little effect on frequency characteristics, but is dependent on the alignment and distance between the wireless power transmission device 100 and the wireless power reception device 200. can be influenced by

Additionally, charging efficiency may be affected by the coupling coefficient or mutual inductance between each transmitting coil and the receiving coil 281.

Additionally, charging efficiency may be affected by the reactance of the wireless power transmission device 100 and the wireless power reception device 200 for maximum power transmission.

As described above, although the charging efficiency of the wireless power receiving device 200 varies depending on the arrangement, distance, coupling coefficient, mutual inductance, reactance, etc. between the wireless power transmitting device 100 and the wireless power receiving device 200, the response When selecting a motion coil or a combination of motion coils to be used for wireless power transmission based solely on the response strength of the signal, a transmission coil may appear that has superior charging efficiency but cannot be selected as the motion coil or combination of motion coils due to its low response strength.

In order to solve this problem, the present invention can select an operating coil combination by considering not only the response strength of the response signal but also the charging efficiency of the wireless power receiving device 200.

That is, the control unit 160 may select the operating coil combination to be used for wireless power transmission from the coil combinations based on the response strength of the response signal to the coil selection signal and the charging efficiency of the wireless power receiving device 200 (S790) ).

Specifically, when a response signal to the coil selection signal is received, the control unit 160 may apply a weight that increases in proportion to charging efficiency to the response strength of the response signal.

Additionally, the controller 160 may select, among coil combinations, the coil combination with the greatest response strength of the weighted response signal as the operating coil combination to be used for wireless power.

For example, in the basic mode, when the receiving coil 281 is placed as shown in FIG. 12A, the coil combination with the largest response signal may be the fourth coil combination including only the fourth transmitting coil 184. At this time, the response strength of the response signal according to the fourth coil combination may be 4.8V.

Meanwhile, the response strength of the response signal according to the 11th coil combination, in which the third transmission coil 183 is set as the main transmission coil and the fourth transmission coil 184 is set as the auxiliary transmission coil, may be 4.2V. . In addition, the response strength of the response signal according to the twelfth coil combination, in which the third transmission coil 183 is set as the auxiliary transmission coil and the fourth transmission coil 184 is set as the main transmission coil, may be 4.3V. .

The reason why the response strength of the response signal according to the 11th coil combination or the 12th coil combination is smaller than the response strength of the response signal according to the fourth coil combination is that the third transmission coil 183 and the fourth transmission coil 184 overlap. This may be because the receiving coil 281 is not aligned with any one of the third transmission coil 183 and the fourth transmission coil 184.

However, due to the overlapping area of the third transmission coil 183 and the fourth transmission coil 184, the charging efficiency is lower than when transmitting power using only the fourth transmission coil 184. The case of transmitting power through a coil combination of the fourth transmission coil 184 may be greater.

Accordingly, the control unit 160 may apply a weight according to charging efficiency to the response signal strength for the coil combination of the third transmission coil 183 and the fourth transmission coil 184. For example, the control unit 160 may multiply 4.2V, which is the response signal strength according to the 11th coil combination, by a weight of 1.1, or add a weight of 0.6 to 4.2V. Additionally, the control unit 160 may multiply 4.3V, which is the response signal strength according to the twelfth coil combination, by a weight of 1.2, or add a weight of 0.8V to 4.3V.

As a result of applying weight to the response strength, the response strength according to the twelfth coil combination is greater than the response strength according to the fourth coil combination, so the control unit 160 controls the third transmission coil 183 and the fourth transmission coil 184 The twelfth coil combination of can be selected as the operating coil combination to be used for wireless power.

Accordingly, the wireless power transmission device 100 of the present invention can charge the wireless power reception device 200 by combining the third transmission coil 183 and the fourth transmission coil 184 with excellent charging efficiency.

Likewise, when the receiving coil 281 is placed as shown in FIG. 12b, the coil combination with the largest response signal may be the first coil combination including only the first transmitting coil 181, but the first transmitting coil 181 and the first coil combination may be 4 Since the charging efficiency of the seventh coil combination of the transmitting coil is higher than the first coil combination, the control unit 160 applies a weight according to the charging efficiency to the response strength and selects the seventh coil combination as the operating coil combination to be used for wireless power. You can choose.

Meanwhile, the control unit 160 can set the weight so that the weight increases for a coil combination with a smaller number of transmission coils.

For example, when the wireless power receiving device 200 is aligned with the transmitting coil as shown in FIG. 11A, the control unit 160 controls the third transmitting coil 183 and the fourth transmitting coil 184. Since the number of transmission coils in the fourth coil combination including the fourth transmission coil 184 is smaller than the coil combination including the coil combination or the coil combination including the first transmission coil 181 and the fourth transmission coil 184, Additional points may be selectively assigned to the weight of the fourth coil combination. Ultimately, the weight can be increased for coil combinations with fewer transmitting coils.

Accordingly, the control unit 160 may select the fourth coil combination with the largest response signal strength of the weighted response signal as the operating coil combination to be used for wireless power.

Meanwhile, the additional points added to the coil combination can be appropriately set in consideration of the alignment of the receiving coil 281.

Next, after selecting the operating coil combination, the control unit 160 may charge the wireless power receiving device 200 with the selected operating coil combination through the steps described in FIG. 6 .

If there is only one operating coil included in the selected operating coil combination, the corresponding operating coil becomes the main transmission coil, and the control unit 160 wirelessly transmits power to the wireless power receiving device 200 through the main transmitting coil. , it is possible to communicate with the wireless power reception device 200 through the corresponding operating coil.

When there are multiple operating coils included in the selected operating coil combination, the control unit 160 may transmit and communicate wireless power through the main transmission coil and assist wireless power transmission through the remaining auxiliary coils.

FIG. 14 is a flowchart for explaining a method of selecting an operating coil combination according to another embodiment of the present invention, and FIG. 15 is a diagram referenced in the description of FIG. 14 .

When explaining with reference to the drawings, in the basic mode, when generating a coil combination as in S710 described above, the wireless power transmitter 100 uses a coil selection digital ping (SCDP) even though it is obvious that it will not be selected as an operating coil combination. ) There are cases where a signal is transmitted.

For example, when the receiving coil 281 is placed as shown in FIG. 12A, the coil combination including the first transmitting coil 181 and the second transmitting coil 182 operates with reduced response strength and charging efficiency of the response signal. It is obvious that it will not be selected as a coil combination.

Therefore, the coil selection signal according to this coil combination may cause a delay in the operation coil selection time as well as a delay in the charging time.

To solve this problem, the control unit 160 may output an object detection signal before transmitting the coil selection signal and calculate an invalid transmission coil based on the object detection signal. Additionally, the control unit 160 can generate a coil combination excluding such invalid coils.

First, the control unit 160 may transmit an object detection signal through a plurality of transmission coils (S1410).

Specifically, the control unit 160 may transmit object detection signals in a predetermined order through a plurality of transmission coils. The control unit 160 may transmit the object detection signal before transmitting the coil selection signal. At this time, the object detection signal may be an analog ping (AP) signal. Additionally, Tb, the time at which the object detection signal is output, may be 120 ms.

When the power transmission unit 180 is provided with first to fourth transmission coils 181 to 184, the control unit 160 sequentially transmits an object detection signal from the first transmission coil 181 to the fourth transmission coil 184. can be output. Accordingly, as shown in FIG. 15, a total of four object detection signals can be output.

Meanwhile, as shown in FIGS. 4 and 5, the first to fourth transmission coils 181 to 184 partially overlap to form a layer, so each transmission coil transmits an object detection signal with the same transmission intensity. In this case, the strength of each object detection signal on the charging surface where the wireless power receiving device 200 is placed may be different.

Differences in the intensity of object detection signals on the charging surface may cause errors in effective coil combinations.

Accordingly, the control unit 160 may transmit an object detection signal by compensating for the distance between each transmitting coil and the charging surface on which the wireless power receiving device 200 is placed. Accordingly, in terms of charging, the strength of each object detection signal may be the same.

Meanwhile, in the case of the inductive coupling method, when an object including the wireless power receiving device 200 is placed on the charging surface, the current of the transmitting coil may change.

In addition, when the power transmission unit 180 is partially overlapped as shown in FIGS. 4 and 5, even if the receiving coil 281 is placed as shown in FIG. 12A, the first transmission coil 181 and the second transmission coil 182 ) The current can also change. However, the amount of current change in the first transmission coil 181 and the second transmission coil 182 may be smaller than the amount of current change in the third transmission coil 183 and the fourth transmission coil 184.

Accordingly, the control unit 160 may calculate an invalid transmitting coil based on the amount of current change in the transmitting coil for each object detection signal (S1430). An invalid transmitting coil may mean a transmitting coil that is not used in coil combination.

If the current change amount is less than a preset current change amount, the control unit 160 may calculate the corresponding transmission coil as an invalid transmission coil. Conversely, if the amount of current change is greater than or equal to a preset amount of current change, the control unit 160 may calculate the corresponding transmitting coil as an effective transmitting coil.

The effective transmitting coil may refer to a transmitting coil included in an effective coil combination, which will be described later. For example, in FIG. 12A, the ineffective transmitting coils are the first transmitting coil 181 and the second transmitting coil 182, and the effective transmitting coils are the third transmitting coil 183 and the fourth transmitting coil 184. It can be.

The control unit 160 may exclude invalid transmission coils when generating a coil combination (S1450). Additionally, the control unit 160 may generate a valid coil combination excluding the invalid transmission coil (S1470). The effective coil combination may refer to a coil combination that will output a coil selection signal.

For example, in FIG. 12A, when combining coils, the control unit 160 excludes the first transmission coil 181 and the second transmission coil 182, which are ineffective transmission coils, and the third transmission coil ( 183) and the fourth transmission coil 184 can be used to generate an effective coil combination.

Meanwhile, when there are a plurality of effective transmission coils, the control unit 160 may generate an effective coil combination such that it includes at least one effective transmission coil among the plurality of effective transmission coils.

For example, in FIG. 12A, when the control unit 160 generates an effective coil combination by selecting only one effective transmission coil among a plurality of effective transmission coils, the control unit 160 selects the third transmission coil 183. By selecting the first effective coil combination and the fourth transmission coil 184, a second effective coil combination can be generated.

At this time, the control unit 160 may set the third transmission coil 183 or the fourth transmission coil 184 as the main transmission coil to perform wireless power transmission and communication.

Additionally, in FIG. 12A, when the control unit 160 selects all of a plurality of effective transmission coils to generate an effective coil combination, the control unit 160 selects the third transmission coil 183 and the fourth transmission coil 184. Select a third effective coil combination in which the third transmission coil 183 is set as the main transmission coil and the fourth transmission coil 184 is set as the auxiliary transmission coil, and the third transmission coil 183 is set as the auxiliary transmission coil. It is possible to create a fourth effective coil combination in which the fourth transmission coil 184 is set as the main transmission coil.

Next, the control unit 1490 may select an operating coil combination from the effective coil combinations (S1490).

Specifically, the control unit 160 may transmit a coil selection signal through an effective transmitting coil included in the effective coil combination and receive a coil selection response signal for the coil selection signal.

The difference from FIG. 7 is that the control unit 160 transmits the coil selection signal only with effective coil combinations, so the number of transmissions of the coil selection signal is reduced.

For example, in Figure 9, the number of transmissions of the coil selection signal according to the coil combination is a total of 12, while in Figure 15, the number of transmissions of the coil selection signal according to the effective coil combination can be reduced to a total of 4. .

Additionally, in FIG. 9, the transmission time (Ta) of the coil selection signal may be about 1200 ms, while in FIG. 15, the transmission time (Tc) of the coil selection signal may be about 400 ms.

In addition, even when calculating the coil selection time including the transmission time (Tb) of the object detection signal in FIG. 15, the transmission period of the object detection signal is more than 3 times less than the transmission period of the coil selection signal, so the effective coil In the case of FIG. 15 in which the coil selection signal is transmitted using a combination, the coil selection time is significantly reduced compared to the case in FIG. 9 in which the coil selection signal is transmitted using a coil combination.

Experimentally, the transmission time Ta of FIG. 9 is about 1200 ms, while the transmission time Tb+Tc of FIG. 15 is reduced by more than half to about 520 ms.

Furthermore, by reducing the coil selection time, the total charging time can be reduced, the number of transmissions of the coil selection signal can be reduced, and the power consumption of the wireless power transmission device 100 can also be reduced.

Meanwhile, when the control unit 160 receives a response signal, as shown in FIG. 7, based on the response strength of the response signal and the charging efficiency of the wireless power receiving device, among the effective coil combinations, an operating coil to be used for wireless power transmission is selected. A combination may be selected, and the wireless power receiving device 200 may be charged through the selected operating coil combination.

Specifically, when a response signal to the coil selection signal is received, the control unit 160 may apply a weight that increases in proportion to charging efficiency to the response strength of the response signal.

Additionally, the control unit 160 may set the weight to increase for coil combinations with fewer transmission coils.

Additionally, the controller 160 may select, among coil combinations, the coil combination with the greatest response strength of the weighted response signal as the operating coil combination to be used for wireless power.

Additionally, after selecting the operating coil combination, the control unit 160 may charge the wireless power receiving device 200 with the selected operating coil combination through the steps described in FIG. 6 .

Figure 16 is a flowchart for explaining a method of selecting an operating coil combination according to another embodiment of the present invention.

When described with reference to the drawings, the wireless power transmission device 100 includes one (single) or two (dual) transmission coils among the first to fourth transmission coils 181 to 184, as shown in FIGS. 7 to 13. When only is selected to generate a coil combination, there may be a limit to the amount of power transmitted from the wireless power transmission device 100.

In addition, since the size of the receiving coil 281 is usually increased in proportion to the required power of the wireless power receiving device 200, one or two of the first to fourth transmitting coils 181 to 184 are used. When generating a coil combination by selecting only a (dual) transmission coil, the wireless power transmission device 100 and the wireless power reception device 200 cannot be aligned, which may reduce charging efficiency.

To solve this problem, the wireless power transmission device 100 can change the number of operating coils included in the coil combination depending on the power of the wireless power reception device 200.

First, the power transmitter 180 may receive unique information from the wireless power receiver 200 (S1610). The unique information may include product information of the wireless power receiving device 200, particularly power consumption information.

Next, the control unit 160 may calculate the power of the wireless power reception device 200 based on the unique information (S1630). At this time, power may refer to the power consumption of the wireless power reception device 200. Alternatively, when the load of the wireless power receiving device 200 is a battery, power may mean the required power of the battery.

Next, the control unit 160 may calculate the number of operating coils to be operated for wireless power transmission based on the power of the wireless power receiving device 200 (S1650). Additionally, the control unit 160 may generate a coil combination according to the number of operating coils to be operated (S1670).

When the calculated power of the wireless power receiving device 200 is included in the first range, the control unit 160 includes one or two transmitting coils among the first to fourth transmitting coils 181 to 184. A transmission coil can be created as much as possible. For example, the first range may be from 0W to 15W.

Ultimately, when the power of the wireless power reception device 200 is included in the first range, the wireless power transmission device 100 may operate in the basic mode, as shown in FIG. 7 .

When the power of the wireless power receiving device 200 is included in the second range that is larger than the first range, the control unit 160 transmits three or four of the first to fourth transmission coils 181 to 184. You can create coil combinations to include coils. For example, the second range may be a range of 15W to 30W.

When generating a coil combination by selecting three transmission coils in the second range, the control unit 160 selects the first transmission coil 181, the second transmission coil 182, and the third transmission coil 183. Thus, the first coil combination can be created. Likewise, the control unit 160 selects the second transmission coil 182, the third transmission coil 183, and the fourth transmission coil 184, and selects the second coil combination, the third transmission coil 183, By selecting the fourth transmission coil 184 and the first transmission coil 181, by selecting the third coil combination, the fourth transmission coil 184, the first transmission coil 181, and the second transmission coil 182 , a fourth coil combination can be created.

In addition, when generating a coil combination by selecting four transmitting coils in the second range, the control unit 160 selects the first to fourth transmitting coils 181 to 184 to generate a fifth coil combination. You can.

When the power of the wireless power receiving device is within the third range that is greater than the second range, the control unit 160 may select all of the first to fourth transmission coils 181 to 184 as a coil combination. For example, the third range may be a range from 30W to 60W.

As the wireless power transmission device 100 changes the number of transmission coils included in the coil combination according to the capacity of the wireless power transmission device 200, the wireless power transmission device 100 receives wireless power of various powers. The device 200 can be charged.

Figure 17 is a flowchart for explaining a method of selecting an operating coil combination according to another embodiment of the present invention.

When described with reference to the drawings, as described above, the wireless power transmission device 100 can communicate with the wireless power reception device 200 using an in-band communication method.

During in-band communication, the wireless power transmission device 100 modulates the first transmission target packet containing various control information by FSK (Frequency Shift Keying) communication method, and the wireless power transmission device 100 ) can be transmitted to.

In addition, during in-band communication, the wireless power receiving device 100 modulates the second transmission target packet by ASK (Amplitude-Shift Keying) communication method and transmits it to the wireless power receiving device 200. You can.

The second transmission target packet may include current intensity information applied to the receiving coil 281, load required power information, received power intensity information, status information, etc.

Meanwhile, the FSK communication method is only advantageous for transmitting a few bytes of packets to be transmitted, but there is a problem in that the transmission speed decreases as the capacity of the packet to be transmitted increases.

In particular, as the power of the wireless power receiving device 200 increases, the amount of data to be transmitted for authentication or control of the wireless power receiving device 200 also increases, so in the case of a large capacity wireless power receiving device 200, communication Time may be increased. This increase in communication time may eventually lead to an increase in charging time.

To solve this problem, the control unit 160 may vary the communication method depending on the power of the wireless power reception device 200.

First, the power transmitter 180 may receive unique information from the wireless power receiver 200 (S1710).

Specifically, the wireless power receiving device 200 may transmit unique information of the wireless power receiving device 200 at the request of the wireless power transmitting device 100 or periodically through an in-band communication method. The unique information may include product information of the wireless power receiving device 200, particularly power consumption information and device address information.

The wireless power reception device 200 may transmit unique information in at least one of the selection step (S610), step (S620), or identification and configuration step (S630) of FIG. 6.

Next, the control unit 160 may calculate the power of the wireless power reception device 200 based on the unique information (S1730). At this time, power may refer to the power consumption of the wireless power reception device 200. Alternatively, when the load of the wireless power receiving device 200 is a battery, power may mean the required power of the battery.

Next, the control unit 160, in a state of communicating with the wireless power receiving device 200 through in-band communication, uses a method of communicating with the wireless power receiving device 200 based on the calculated power of the wireless power receiving device 200. It is possible to calculate whether or not there is a change (S1750).

The control unit 160 may maintain in-band communication when the calculated power of the wireless power receiving device is less than the reference power (S1770).

At this time, the reference power may be equal to the upper limit of the second range or the lower limit of the third range in FIG. 16. For example, the power range of the wireless power receiving device 200 is divided into a first range (0W to 15W), a second range (15W to 30W), and a third range (30W to 60W), as shown in FIG. 16. In this case, the reference power may be 30W.

The control unit 160 may communicate with the wireless power reception device 200 through in-band communication through the first communication unit 140.

The first communication unit 140 processes status information, power control information, etc. of the wireless power transmission device 200 into a predetermined signal and transmits it to the wireless power reception device 200 through in-band communication. ) status information, power usage information, charging efficiency information, etc. can be received through in-band communication, processed as a predetermined signal, and then transmitted to the control unit 160.

Depending on the embodiment, the first communication unit 140 may be included as a part of the control unit 160.

If the calculated power of the wireless power receiving device 200 is higher than the reference power, the control unit 160 changes the communication method to communicate with the wireless power receiving device 200 through out-of-band communication. Communication is possible (S1790).

The control unit 160 may communicate with the wireless power reception device 200 through out-of-band communication through the second communication unit 150.

The second communication unit 140 processes status information, power control information, etc. of the wireless power transmission device 200 into a predetermined signal and transmits it to the wireless power reception device 200 through out-of-band communication. , Status information, power usage information, charging efficiency information, etc. of the wireless power receiving device 200 may be received through out-of-band communication, processed as a predetermined signal, and then transmitted to the control unit 160. .

Out-of-band communication may be any one of Bluetooth communication, BLE (Bluetooth Low Energy) communication, NFC (Near Field Communication), RFID (Radio Frequency Identification) communication, or Zigbee communication. .

The second communication unit 150 may be provided in the wireless power transmission device 100 in a module form. For example, the BLE communication module may be electrically connected to the control unit 160 within the wireless power transmission device 100.

Meanwhile, the control unit 160 of the present invention can be implemented as processor-readable code on a processor-readable recording medium provided in the power transmission device 100. Processor-readable recording media includes all types of recording devices that store data that can be read by a processor. Examples of recording media that can be read by a processor include ROM, RAM, CD-ROM, magnetic tape, floppy disk, and optical data storage devices, and also include those implemented in the form of a carrier wave, such as transmission through the Internet. . Additionally, the processor-readable recording medium is distributed in a computer system connected to a network, so that the processor-readable code can be stored and executed in a distributed manner.

In addition, although preferred embodiments of the present invention have been shown and described above, the present invention is not limited to the specific embodiments described above, and the technical field to which the invention pertains without departing from the gist of the present invention as claimed in the claims. Of course, various modifications can be made by those of ordinary skill in the art, and these modifications should not be understood individually from the technical idea or perspective of the present invention.

10: Wireless power system
100: wireless power transmission device
160: control unit
180: Power transmission unit
181: first transmitting coil
182: first transmitting coil
183: first transmitting coil
184: first transmitting coil
200: Wireless power receiving device

Claims (10)

A power transmission unit comprising a plurality of partially overlapping transmission coils and wirelessly transmitting power to a wireless power reception device through one coil combination selected from the plurality of transmission coils; and
Among the plurality of transmitting coils, the coil combination is generated to include at least one transmitting coil, a coil selection signal is transmitted through the transmitting coil included in the coil combination, and the coil selection signal is transmitted through the transmitting coil. A control unit that receives a response signal and selects an operating coil combination to be used for wireless power transmission among the coil combinations based on the response strength of the response signal and charging efficiency of the wireless power receiving device,
The control unit
When a response signal to the coil selection signal is received, a weight that increases in proportion to the charging efficiency is applied to the response strength of the response signal, and among the coil combinations, the response strength of the response signal to which the weight is applied is A wireless power transmission device that selects the largest coil combination as the operating coil combination. According to paragraph 1,
The power transmission unit,
A wireless power transmission device comprising first to fourth transmission coils arranged to partially overlap according to a preset order. According to paragraph 2,
The control unit,
A wireless power transmission device, characterized in that one or two transmission coils are selected from among the first to fourth transmission coils to generate the coil combination. According to paragraph 1,
The control unit,
When generating the coil combination by selecting one transmitting coil among the plurality of transmitting coils, the selected one transmitting coil is set as a main transmitting coil to perform wireless power transmission and communication, and the coil selection signal is provided. A wireless power transmission device characterized in that it transmits. According to paragraph 1,
The control unit,
When creating the coil combination by selecting two or more transmitting coils among the plurality of transmitting coils, one transmitting coil is set as the main transmitting coil to perform wireless power transmission and communication, and the remaining transmitting coils are set as the wireless transmitting coil. A wireless power transmission device characterized in that it is set as an auxiliary transmission coil to assist power transmission and transmits the coil selection signal. delete According to paragraph 1,
The control unit,
A wireless power transmission device, wherein the weight is set to increase as the number of transmission coils decreases in the coil combination. According to paragraph 1,
The control unit,
A wireless power transmission device, characterized in that calculating the charging efficiency of the wireless power reception device based on the ratio of the power supplied to the load provided in the wireless power reception device and the required power of the load. According to paragraph 1,
It further includes a memory that stores the transmission intensity of each coil selection signal transmitted from the plurality of transmission coils,
The transmission intensity is,
A wireless power transmission device, characterized in that it is set by compensating the distance between each transmission coil and the charging surface on which the wireless power reception device is placed. According to paragraph 1,
The coil selection signal is,
A wireless power transmission device characterized by a digital ping signal.

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