Wireless power supply system

Abstract

This wireless power supply system (10) comprises: a power reception device (20); a power transmission device (30) that wirelessly supplies power to the power reception device; and a wireless access point (40) that can communicate with the power reception device and the power transmission device. The power transmission device comprises a first communication unit (22) that carries out wireless communication with the power reception device, said communication pertaining to the state of supplying power by means of wireless power supply. The power reception device comprises a second communication unit (32) that carries out wireless communication with the power transmission device, said communication pertaining to the state of supplying power by means of the wireless power supply. The wireless access point (40) detects radio wave status information that indicates the propagation status of the wireless communication. The first communication unit and the second communication unit acquire the radio wave status information by communicating with the wireless access point, and at least one of the power reception device and the power transmission device performs control so as to limit the wireless power supply if it has been determined that a mobile body is present within the effective power supplying range of the power transmission device.

Description

Wireless power supply system

[0001] The present invention relates to a wireless power supply system.

[0002] Patent Document 1 discloses a wireless power feeding system that uses a magnetic field resonance method to wirelessly feed power from a wireless power feeding device to a wireless power receiving device.

[0003] Japanese Patent Application Laid-Open No. 2023-29924

[0004] However, when power is supplied wirelessly, if a moving object such as a person, animal, or robot is present near the power supply path, there is a risk that the moving object may be affected.

[0005] Therefore, an object of the present invention is to provide a wireless power supply system that can suppress the influence on a moving object.

[0006] A wireless power supply system according to one embodiment of the present invention comprises a power receiving device, a power transmitting device that wirelessly supplies power to the power receiving device, and a wireless access point that can communicate freely with each of the power receiving device and the power transmitting device, wherein the power transmitting device comprises a first communication unit that performs wireless communication with the power receiving device regarding the state of power supply by wireless power supply, and the power receiving device comprises a second communication unit that performs wireless communication with the power transmitting device regarding the state of power supply by wireless power supply, the wireless access point detects radio wave condition information that indicates the propagation state of the wireless communication, the first communication unit and the second communication unit acquire the radio wave condition information by communicating with the wireless access point, and at least one of the power receiving device and the power transmitting device controls to limit the wireless power supply when it determines that a moving object is present within the effective power supply range of the power transmitting device.

[0007] According to the wireless power supply system of the present invention, the influence on the moving body can be suppressed.

[0008] Fig. 1 is a schematic diagram of a wireless power supply system according to an embodiment. Fig. 2 is an explanatory diagram showing a case where a mobile object according to the embodiment does not exist within an effective power supply range. Fig. 3 is an explanatory diagram showing a case where a mobile object according to the embodiment exists within an effective power supply range.

[0009] Hereinafter, wireless power supply systems according to embodiments of the present invention will be described in detail with reference to the drawings. Note that each of the embodiments described below represents a specific example of the present invention. Therefore, the numerical values, shapes, materials, components, component arrangements, and connection configurations shown in the following embodiments are merely examples and are not intended to limit the present invention. Therefore, among the components in the following embodiments, components that are not recited in independent claims will be described as optional components.

[0010] Furthermore, each figure is a schematic diagram and is not necessarily an exact illustration. Therefore, for example, the scales of the figures do not necessarily match. Furthermore, in each figure, substantially the same components are given the same reference numerals, and redundant explanations are omitted or simplified.

[0011] Furthermore, in this specification, terms indicating the relationship between elements, terms indicating the shape of elements, and numerical ranges are not expressions that only express a strict meaning, but are expressions that also include a substantially equivalent range, for example, a difference of about a few percent.

[0012] (Embodiment) First, a wireless power supply system 10 according to an embodiment will be described with reference to Fig. 1. Fig. 1 is a schematic diagram of the wireless power supply system 10 according to the embodiment. As shown in Fig. 1, the wireless power supply system 10 includes a power receiving device 20, a power transmitting device 30, and a wireless access point 40.

[0013] The power receiving device 20 is a device that receives power wirelessly supplied from the power transmitting device 30. The power receiving device 20 is, for example, a wired power supply device that supplies power to other electrically connected devices. Alternatively, the power receiving device 20 may be a charging device that charges with power wirelessly supplied from the power transmitting device 30. The power receiving device 20 may itself be an electronic device such as a PC or a smartphone. In this case, the power receiving device itself is driven by the wirelessly supplied power.

[0014] The power receiving device 20 includes a wireless power receiving unit 21 , a first communication unit 22 , and a first control unit 23 .

[0015] The wireless power receiving unit 21 is a power receiving module that receives power wirelessly fed from the power transmitting device 30. Here, the wireless power receiving unit 21 has a power receiving structure compatible with the wireless power feeding method adopted by the power transmitting device 30. Wireless power feeding methods include, for example, a magnetic field feeding method and a microwave feeding method. Magnetic field feeding methods include an electromagnetic induction method, a magnetic field resonance method, a magnetic field coupling method, and the like.

[0016] The first communication unit 22 is a wireless communication module that performs wireless communication with other communication devices, for example, via Wi-Fi (registered trademark), Bluetooth, etc. The first communication unit 22 can freely communicate with the wireless access point 40 and the second communication unit 32 of the power transmission device 30.

[0017] The first control unit 23 is electrically connected to the wireless power receiving unit 21 and the first communication unit 22, and controls the wireless power receiving unit 21 and the first communication unit 22. Specifically, the first control unit 23 includes a CPU, RAM, ROM, etc., and the CPU executes each process by expanding a program in the ROM into the RAM and executing it.

[0018] The power transmitting device 30 includes a wireless power supply unit 31 , a second communication unit 32 , and a second control unit 33 .

[0019] The wireless power supply unit 31 is a wireless power supply module that supplies power wirelessly. When the wireless power supply unit 31 is supplying power wirelessly and the power receiving device 20 enters its effective power supply range R (see FIG. 2 ) and enters a state in which power reception is permitted, the wireless power receiving unit 21 accepts wireless power supply from the wireless power supply unit 31. The effective power supply range R is a range in which the wireless power supply unit 31 can effectively supply power wirelessly, and is an elliptical range centered on the power transmitting device 30.

[0020] The second communication unit 32 is a wireless communication module that performs wireless communication, and performs wireless communication with other communication devices via, for example, Wi-Fi or Bluetooth. The second communication unit 32 can freely communicate with the wireless access point 40 and the first communication unit 22 of the power receiving device 20.

[0021] The second control unit 33 is electrically connected to the wireless power supply unit 31 and the second communication unit 32, and controls the wireless power supply unit 31 and the second communication unit 32. Specifically, the second control unit 33 includes a CPU, RAM, ROM, etc., and the CPU executes each process by expanding a program in the ROM into the RAM and executing it.

[0022] The wireless access point 40 is connected to, for example, a home network, a public wireless LAN network, etc., and connects wireless terminals to each other via Wi-Fi. The wireless access point 40 supports two bands used for wireless communication: a first band (for example, the 2.4 GHz band) and a second band (for example, the 5 GHz band) that is a frequency band higher than the first band.

[0023] In Wi-Fi communications, wireless terminals provide the wireless access point 40 with feedback on the radio wave conditions of the channels received by each wireless terminal, referred to as CSI (Channel State Information). This CSI information makes it possible to detect the position of a mobile object P (person, animal, robot, etc.; see FIGS. 2 and 3 ) present around the wireless access point 40. The CSI information is an example of wireless condition information indicating the radio wave conditions of wireless communications according to the present disclosure. For example, when detecting the position of a mobile object P using the CSI information, the position can be detected with an accuracy on the order of 1 meter. The wireless access point 40 also communicates CSI information when communicating with the power receiving device 20 and the power transmitting device 30.

[0024] [Method of Supplying Power by Wireless Power Supply] Next, a method of supplying power by wireless power supply between the power receiving device 20 and the power transmitting device 30 will be described.

[0025] The second control unit 33 of the power transmitting device 30 controls the wireless power supply unit 31 to wirelessly supply power via the wireless power supply unit 31. In this state, when the power receiving device 20 enters the effective power supply range R of the wireless power supply unit 31, the first control unit 23 of the power receiving device 20 permits power reception. As a result, the wireless power receiving unit 21 receives wireless power from the wireless power supply unit 31.

[0026] Here, at least one of the second control unit 33 of the power transmitting device 30 and the first control unit 23 of the power receiving device 20 determines whether the mobile object P is present within the effective power supply range R based on the CSI information received from the wireless access point 40. Here, an example is shown in which the second control unit 33 makes this determination, but the same applies to the first control unit 23.

[0027] 2 is an explanatory diagram showing a case where a mobile object P according to the embodiment does not exist within an effective power supply range R. As shown in FIG. 2 , when the second control unit 33 communicates with the wireless access point 40 and acquires CSI information, the second control unit 33 determines that the mobile object P does not exist within the effective power supply range R.

[0028] 3 is an explanatory diagram showing a case where a mobile object P according to the embodiment is present within an effective power supply range R. As shown in FIG. 3 , when the second control unit 33 communicates with the wireless access point 40 and acquires CSI information, the second control unit 33 determines that the mobile object P is present within the effective power supply range R.

[0029] Here, Wi-Fi sensing is accurate enough to determine whether a mobile object P is present within a square s1 with sides of approximately 1 m. For example, as shown in FIG. 3 , an oval area with a length of 1.5 m centered on the power transmitting device 30 is defined as the active power supply range R. In this case, the second control unit 33 determines whether the mobile object P is present inside or outside the active power supply range R based on a reference area s20 of 9 squares (3 m x 3 m) centered on the power transmitting device 30. Specifically, if the mobile object P is present within the reference area s20 based on the CSI information, the second control unit 33 determines that the mobile object P is present within the active power supply range R. On the other hand, if the mobile object P is present outside the reference area s20 based on the CSI information, the second control unit 33 determines that the mobile object P is not present within the active power supply range R.

[0030] The determination of whether the mobile object P is present within the effective power supply range R is not limited to this, as long as it is based on the CSI information. For example, the wireless access point 40 detects the position of the mobile object P based on the CSI information. The wireless access point 40 then detects the position of the power transmission device 30 by communicating with the power transmission device 30. The wireless access point 40 transmits the detected positions of the mobile object P and the power transmission device 30 to the power transmission device 30. The second control unit 33 of the power transmission device 30 may determine whether the mobile object P is present within the effective power supply range R based on the acquired positions of the mobile object P and the power transmission device 30 and the previously recognized effective power supply range R.

[0031] When the second control unit 33 determines that the mobile object P is present within the effective power supply range R, it controls to limit the wireless power supply. Specifically, the second control unit 33 limits the wireless power supply by interrupting the wireless power supply or reducing the power supplied during wireless power supply. This suppresses the influence of the wireless power supply on the mobile object P present within the effective power supply range R.

[0032] Thereafter, when the second control unit 33 determines that the mobile object P is not present within the effective power supply range R, it releases the restriction on wireless power feeding. That is, if wireless power feeding has been interrupted, wireless power feeding is resumed. Also, if the supply power during wireless power feeding has been reduced, the supply power is restored to its original level. As a result, when the mobile object P is not present within the effective power supply range R, normal wireless power feeding can be performed while ensuring the safety of the mobile object P.

[0033] When the first control unit 23 determines whether or not the moving object is present within the effective power supply range, the first control unit 23 may transmit the determination result (first determination result) to the power transmission device 30. In this case, the second control unit 33 of the power transmission device 30 determines whether or not to restrict wireless power feeding based on the first determination result.

[0034] Furthermore, the first control unit 23 may determine whether or not wireless power feeding is restricted based on the first determination result (second determination result) and transmit the second determination result to the power transmission device 30. In this case, the second control unit 33 of the power transmission device 30 controls wireless power feeding based on the second determination result.

[0035] (Effects, etc.) As described above, according to the wireless power feeding system 10 according to the above embodiment, at least one of the power receiving device 20 and the power transmitting device 30 performs control to limit wireless power feeding when it is determined based on the CSI information that a moving object P is present within the effective power supply range R of the power transmitting device 30. As a result, the power supplied by wireless power feeding is suppressed more than in normal times, and the impact on the moving object P present within the effective power supply range R can be suppressed.

[0036] When at least one of the power receiving device 20 and the power transmitting device 30 determines that a moving object P is present within the effective power supply range R, it suspends wireless power feeding or reduces the power supplied during wireless power feeding, thereby more reliably suppressing the power supplied by wireless power feeding than in normal times. Therefore, it is possible to more reliably suppress the impact on the moving object P present within the effective power supply range R.

[0037] If at least one of the power receiving device 20 and the power transmitting device 30 determines after imposing a restriction that no mobile body P is present within the effective power supply range R, it releases the restriction, thereby enabling normal wireless power supply to be carried out while ensuring the safety of the mobile body P.

[0038] (Others) While the wireless power supply system according to the present invention has been described above based on the above-mentioned embodiments, the present invention is not limited to the above-mentioned embodiments. The present invention also includes forms obtained by applying various modifications to the embodiments that would occur to those skilled in the art, and forms realized by arbitrarily combining the components and functions of the embodiments within the scope of the present invention.

[0039] For example, when the CSI information indicates that the moving object P is not present within the effective power supply range R, at least one of the power receiving device 20 and the power transmitting device 30 may set the wireless communication band to the second band. This allows the CSI information to be acquired in the second band at subsequent determinations. As described above, the second band is a higher frequency band than the first band, and therefore the resolution of Wi-Fi sensing can be improved, making it possible to detect the moving object P with high accuracy.

[0040] An example of the wireless power supply system according to the present invention, which has been described based on the above embodiment, will be described below. However, the wireless power supply system according to the present invention is not limited to the following example.

[0041] For example, a wireless power supply system according to a first aspect of the present invention comprises: a power receiving device; a power transmitting device that wirelessly supplies power to the power receiving device; and a wireless access point that can communicate freely with each of the power receiving device and the power transmitting device, wherein the power transmitting device comprises a first communication unit that performs wireless communication with the power receiving device regarding the state of power supply by wireless power supply; the power receiving device comprises a second communication unit that performs wireless communication with the power transmitting device regarding the state of power supply by wireless power supply; the wireless access point detects radio wave condition information that indicates the propagation state of wireless communication; the first communication unit and the second communication unit acquire the radio wave condition information by communicating with the wireless access point; and at least one of the power receiving device and the power transmitting device controls to limit the wireless power supply when it is determined that a moving object is present within an effective power supply range of the power transmitting device.

[0042] For example, a wireless power feeding system according to a second aspect of the present invention is the wireless power feeding system according to the first aspect, wherein, when at least one of the power receiving device and the power transmitting device determines that a moving object is present within the effective power supply range, the wireless power feeding is limited by interrupting the wireless power feeding or reducing the power supplied during the wireless power feeding.

[0043] For example, a wireless power supply system according to a third aspect of the present invention is the wireless power supply system according to the first or second aspect, wherein at least one of the power receiving device and the power transmitting device releases the restriction when, after imposing the restriction, it is determined that no moving object is present within the effective power supply range.

[0044] For example, a wireless power supply system according to a fourth aspect of the present invention is a wireless power supply system according to any one of the first to third aspects, wherein the wireless access point supports a first band and a second band that is a higher frequency band than the first band as bands used for the wireless communication, and at least one of the power receiving device and the power transmitting device sets the band for the wireless communication to the second band when the radio wave condition information indicates that no moving object is present within the effective power supply range.

[0045] REFERENCE SIGNS LIST 10 Wireless power supply system 20 Power receiving device 22 First communication unit 30 Power transmitting device 32 Second communication unit 40 Wireless access point P Mobile object R Effective power supply range

Claims

1. A wireless power supply system comprising: a power receiving device; a power transmitting device that wirelessly supplies power to the power receiving device; and a wireless access point that can communicate freely with each of the power receiving device and the power transmitting device, wherein the power transmitting device has a first communication unit that performs wireless communication with the power receiving device regarding the state of power supply by wireless power supply, and the power receiving device has a second communication unit that performs wireless communication with the power transmitting device regarding the state of power supply by wireless power supply, the wireless access point detects radio wave condition information that indicates the propagation state of the wireless communication, the first communication unit and the second communication unit acquire the radio wave condition information by communicating with the wireless access point, and at least one of the power receiving device and the power transmitting device controls to limit the wireless power supply when it is determined that a moving object is present within the effective power supply range of the power transmitting device.

2. The wireless power supply system according to claim 1, wherein at least one of the power receiving device and the power transmitting device, when determining that a moving object is present within the effective power supply range, limits the wireless power supply by interrupting the wireless power supply or reducing the power supplied during the wireless power supply.

3. The wireless power supply system according to claim 1 or 2, wherein at least one of the power receiving device and the power transmitting device, after imposing the restriction, releases the restriction if it is determined that no moving object is present within the effective power supply range.

4. The wireless power supply system according to claim 1 or 2, wherein the wireless access point supports a first band and a second band that is a higher frequency band than the first band as bands used for the wireless communication, and at least one of the power receiving device and the power transmitting device sets the band for the wireless communication to the second band when the radio wave condition information indicates that no mobile object is present within the effective power supply range.

Images