JP6153449B2 - Control device, power transmission device, power transmission system, and control method - Google Patents

Description

  The present invention relates to a control device, a power transmission device, a power transmission system, and a control method used in a power transmission system that transmits power from a power transmission device to a plurality of power reception devices by a magnetic resonance method.

  Conventionally, techniques for wirelessly transmitting power from a power transmission device to a power reception device have been studied. For example, a magnetic field resonance method has been proposed as such a wireless power transmission method. Specifically, by adjusting the drive frequency of each resonance circuit so that the resonance circuit of the power transmission device and the resonance circuit of the power reception device resonate at a specific frequency, power is transmitted from the power transmission device to the power reception device wirelessly. (For example, Patent Document 1).

  Since the magnetic field resonance method has a longer power transmission distance from the power transmission device than other wireless power transmission methods (for example, the electromagnetic induction method or the microwave method), a single power transmission device can receive a plurality of power reception devices. Power can be transmitted.

JP 2011-166883 A

  However, when power is transmitted from a single power transmission device to a plurality of power receiving devices by a magnetic resonance method, high power transmission efficiency can be obtained in a region within a predetermined distance from the power transmission device (hereinafter referred to as a proximity region). Outside, the power transmission efficiency is greatly reduced according to the distance from the power transmission device. Therefore, most of the transmitted power of the power transmission device is received by the power receiving device located near the power transmitting device, and the power receiving device located far from the power transmitting device receives the received power compared to the power receiving device located near the power transmitting device. Becomes smaller. That is, since the priority of power supply to the power receiving device is automatically determined according to the distance from the power transmitting device, the power receiving device located far from the power transmitting device may not be able to receive a necessary amount of power.

  In addition, the power transmission efficiency decreases as the number of power receiving apparatuses increases. That is, when a plurality of power receiving devices are located in the proximity region of the power transmitting device, the plurality of power receiving devices share the transmitted power of the power transmitting device, and thus the power received by each power receiving device is small. Therefore, even a power receiving device to which power should be transmitted with priority over other power receiving devices may not be able to receive a necessary amount of power.

  Therefore, the present invention provides a control device capable of preferentially transmitting power to a power receiving device to which power is to be transmitted, in a power transmission system that transmits power from a power transmitting device to a plurality of power receiving devices by a magnetic resonance method. An object is to provide a power transmission device, a power transmission system, and a control method.

The control device according to the first feature is a control device used in a power transmission system that transmits power from a power transmission device to a plurality of power reception devices by a magnetic resonance method. The control device includes a control unit that estimates a power transmission distance that is a distance from the power transmission device for each of the plurality of power reception devices, and the control unit estimates the power transmission estimated for each of the plurality of power reception devices. Based on the distance, at least one power receiving device to be adjusted to a resonance frequency different from the resonance frequency of the power transmitting device is specified among the plurality of power receiving devices , and the resonance frequency of the specified power receiving device is controlled.

  In the first feature, the control unit acquires a power reception voltage of each of the plurality of power reception devices, and estimates the power transmission distance for each of the plurality of power reception devices based on the acquired power reception voltage. .

  In the first feature, when the power transmitting device transmits a communication signal and each of the plurality of power receiving devices receives the communication signal, the control unit receives the communication signal received by each of the plurality of power receiving devices. And the power transmission distance is estimated for each of the plurality of power receiving devices based on the acquired received signal strength.

  In the first feature, when a power receiving device to which power is to be transmitted preferentially is designated from among the plurality of power receiving devices, the control unit has the power transmission distance greater than that of the designated power receiving device. The resonance frequency of the short power receiving device is controlled to be different from the resonance frequency of the power transmission device.

  In the first feature, the control unit further acquires, for each of the plurality of power receiving devices, information indicating whether or not the battery has a storage battery, and the plurality of power receiving devices all transmit power of the power transmitting device. When the efficiency is located in the proximity region of the power transmission device exceeding a predetermined value, the resonance frequency of the power reception device including the storage battery is controlled to be different from the resonance frequency of the power transmission device.

  In the first feature, the control unit further acquires, for each of the plurality of power receiving devices, information indicating whether or not the battery has a storage battery, and the plurality of power receiving devices all transmit power of the power transmitting device. When the efficiency is located in the proximity region of the power transmission device exceeding a predetermined value, the resonance frequency of the power reception device including the storage battery is controlled to be different from the resonance frequency of the power transmission device.

  In the first feature, the control unit further acquires a charge rate of the storage battery for the power receiving device having the storage battery, and when the plurality of power receiving devices are all located in a proximity region of the power transmission device, The resonance frequency of the power receiving device that has a storage battery and the charging rate exceeds a threshold value is controlled to be different from the resonance frequency of the power transmission device.

  In the first feature, when there is a power receiving device having the storage battery in the plurality of power receiving devices and having a longer power transmission distance than a power receiving device having a charging rate exceeding a threshold value, The control unit controls the resonance frequency of the power receiving device that has the storage battery and the charging rate exceeds a threshold value to be different from the resonance frequency of the power transmission device.

The power transmission device according to the second feature is a power transmission device used in a power transmission system that transmits power by a magnetic resonance method. The power transmission device includes a control unit that estimates a power transmission distance that is a distance from the power transmission device for each of the plurality of power reception devices. The control unit, based on the power transmission distance estimated for each of the plurality of power receiving devices, among the plurality of power receiving devices, at least one power receiving to be adjusted to a resonance frequency different from the resonance frequency of the power transmission device. The device is specified, and the resonance frequency of the specified power receiving device is controlled.

The power transmission system according to the third feature is a power transmission system that transmits power by a magnetic resonance method. The power transmission system includes: a power transmission device having a power transmission side resonator that transmits the power; a plurality of power reception devices having a power reception side resonator that receives the power transmitted from the power transmission device; and each of the plurality of power reception devices. And a control device that acquires a power transmission distance that is a distance from the power transmission device. The control device, based on the power transmission distance for each of the plurality of power receiving devices, among the plurality of power receiving devices, at least one power receiving device to be adjusted to a resonance frequency different from the resonance frequency of the power transmission device And the resonance frequency of the identified power receiving apparatus is controlled.

A control method according to a fourth feature is a control method in a control device used in a power transmission system that transmits power from a power transmission device to a plurality of power reception devices by a magnetic resonance method. The control method includes, for each of the plurality of power receiving devices, obtaining a power transmission distance that is a distance from the power transmission device, and based on the power transmission distances for each of the plurality of power receiving devices, Identifying at least one power receiving device to be adjusted to a resonance frequency different from the resonance frequency of the power transmitting device, and controlling the resonance frequency of the specified power receiving device .

  According to the present invention, in a power transmission system that transmits power from a power transmission device to a plurality of power receiving devices by a magnetic resonance method, a control device that can transmit power preferentially to the power receiving device to which power is to be transmitted. A power transmission device, a power transmission system, and a control method can be provided.

FIG. 1 is a diagram illustrating a power transmission system 100 according to the first embodiment. FIG. 2 is a diagram illustrating the power transmission device 10 according to the first embodiment. FIG. 3 is a diagram illustrating the power receiving device 20 according to the first embodiment. FIG. 4 is a diagram illustrating an application scene of the power transmission system 100 according to the first embodiment. FIG. 5 is a diagram illustrating a relationship between the power transmission distance and the power transmission efficiency according to the first embodiment. FIG. 6A is a diagram illustrating an example of a positional relationship between the power transmission device and the power reception device according to the first embodiment. FIG. 6B is a diagram illustrating a power reception voltage of the power reception device according to the first embodiment. Fig.7 (a) is a figure which shows the example of the positional relationship of the power transmission apparatus and power receiving apparatus which concern on 1st Embodiment. FIG. 7B is a diagram illustrating a power reception voltage of the power reception device according to the first embodiment. FIG. 8 is a flowchart showing the control method according to the first embodiment. FIG. 9 is a diagram illustrating an example of a positional relationship between the power transmission device and the power reception device according to the second embodiment. FIG. 10 is a flowchart showing a control method according to the second embodiment. FIG. 11 is a diagram illustrating an example of a positional relationship between the power transmission device and the power reception device according to the third embodiment. FIG. 12 is a diagram illustrating an example of a positional relationship between the power transmission device and the power reception device according to the third embodiment. FIG. 13 is a flowchart showing a control method according to the third embodiment.

  Hereinafter, a power transmission system according to an embodiment of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

  However, it should be noted that the drawings are schematic and ratios of dimensions and the like are different from actual ones. Therefore, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

[Outline of Embodiment]
The control device according to the embodiment is a control device used in a power transmission system that transmits power from a power transmission device to a plurality of power reception devices by a magnetic resonance method. The control device includes a control unit that estimates a power transmission distance that is a distance from the power transmission device for each of the plurality of power reception devices, and the control unit estimates the power transmission estimated for each of the plurality of power reception devices. Based on the distance, the resonance frequency of at least one of the plurality of power receiving devices is controlled.

  In the embodiment, the control device includes a control unit that controls the resonance frequency of at least one of the plurality of power receiving devices based on the power transmission distance estimated for each of the plurality of power receiving devices. As a result, power can be preferentially transmitted to the power receiving device to which power is to be transmitted.

[First Embodiment]
(Power transmission system)
The power transmission system according to the first embodiment will be described below. FIG. 1 is a diagram illustrating a power transmission system 100 according to the first embodiment. FIG. 2 is a diagram illustrating the power transmission device 10 according to the first embodiment. FIG. 3 is a diagram illustrating the power receiving device 20 according to the first embodiment.

  As shown in FIG. 1, the power transmission system 100 includes a power transmission device 10 and a power reception device 20, and is a system that transmits power from the power transmission device 10 to the power reception device 20 by a magnetic field resonance method. Although one power receiving device 20 is illustrated in FIG. 1, a plurality of power receiving devices 20 may be provided in the power transmission system 100. The power receiving device 20 includes a load that operates by the power transmitted by the power transmitting device 10. The power receiving device 20 may be, for example, sensors (human sensor, temperature sensor, illuminance sensor) provided at each position in the room, or a portable device such as a remote controller, a smartphone, or a tablet terminal. There may be. The power transmission device 10 is embedded, for example, in the ceiling or under the floor of a room in order to transmit power to the power receiving device 20. The power transmission apparatus 10 may be referred to as a PTU (Power Transmitting Unit), and the power reception apparatus 20 may be referred to as a PRU (Power Receiving Unit).

  In the first embodiment, the power transmission system 100 further includes an EMS (Energy Management System) 30 that is an example of a control device that controls power of a consumer. The EMS 30 includes a home energy management system (HEMS) installed in a home, a building energy management system (BEMS) installed in a building, and a factory energy management system (FEMS) installed in a factory. ) And the like.

  As illustrated in FIG. 1, the power transmission device 10 includes a power transmission side resonator 11, a power transmission module 12, and a communication module 13.

  The power transmission side resonator 11 is a resonator adjusted to resonate at a specific frequency. Specifically, as illustrated in FIG. 2, the power transmission side resonator 11 includes a capacitor C and an inductance L (coil). For example, by adjusting the capacitance of the capacitor C, the resonance frequency of the power transmission side resonator 11 can be adjusted to a specific frequency.

  The power transmission side resonator 11 further includes a voltmeter 11 </ b> A that detects a voltage at the inductance L. Hereinafter, the voltage value detected by the voltmeter 11 </ b> A is referred to as a power transmission voltage of the power transmission device 10.

  The power transmission module 12 is a module that transmits power. Specifically, as illustrated in FIG. 2, the power transmission module 12 includes an oscillation circuit 12A and a power source 12B. The oscillation circuit 12A is a circuit that adjusts the frequency of the AC power supplied from the power supply 12B to a desired frequency using an inverter or an oscillator. A resonance frequency is created by the oscillation circuit 12A.

  The communication module 13 is a module that communicates with the power receiving device 20. The communication module 13 communicates with the EMS 30 described above. Specifically, the communication module 13 includes a communication unit 13A and a control unit 13B.

  The communication unit 13 </ b> A is connected to the power receiving device 20 wirelessly or by wire, transmits a signal to the power receiving device 20 and the EMS 30, and receives a signal from the power receiving device 20 and the EMS 30. For example, the communication unit 13A transmits a search signal for searching for the power receiving device 20. The communication unit 13A transmits an information request for requesting transmission of information for specifying the type of the power receiving device 20. On the other hand, the communication unit 13 </ b> A receives the authentication ID of the power receiving device 20. The authentication ID is returned from the power receiving device 20 in response to the search signal. The communication unit 13A receives information for specifying the type of the power receiving device 20. Information for specifying the type of the power receiving device 20 is returned from the power receiving device 20 in response to the information request.

  The communication unit 13A transmits the power transmission voltage of the power transmission device 10 to the EMS 30. Further, the communication unit 13 </ b> A receives information indicating the received signal strength of the signal received by the power receiving device 20 from the power receiving device 20. 13 A of communication parts transmit the information which shows the received signal strength of the signal which the power receiving apparatus 20 received to EMS30.

  The control unit 13B controls the power transmission module 12 and the communication module 13. For example, the control unit 13B controls the transmitted power of the power transmission device 10. Specifically, the control unit 13B controls the transmission power of the power transmission device 10 by controlling the power source 12B based on the information acquired by the communication unit 13A.

  Here, it is preferable that the power receiving device 20 as the power transmission target is the power receiving device 20 authenticated by the power transmitting device 10. Therefore, it is preferable that the number of power receiving devices 20 that are power transmission targets is the number of power receiving devices 20 authenticated by the power transmitting device 10.

  The type of the power receiving device 20 that is the power transmission target includes the power received by the power receiving device 20 that is the power transmission target, whether the power receiving device 20 that is the power transmission target has a power storage unit, or the power storage that the power receiving target 20 that is the power transmission target has. It is preferably specified by information indicating the capacity of the unit.

  For example, the control unit 13 </ b> B increases the transmission power of the power transmission device 10 as the number of power receiving devices 20 that are power transmission targets increases. Alternatively, the control unit 13B increases the transmission power of the power transmission device 10 as the power reception power of the power reception device 20 that is the target of power transmission increases.

  As illustrated in FIG. 1, the power receiving device 20 includes a power receiving side resonator 21, a power receiving module 22, and a communication module 23.

  The power receiving side resonator 21 is a resonator adjusted so as to resonate at a specific frequency. Specifically, as shown in FIG. 3, the power receiving resonator 21 includes a capacitor C and an inductance L (coil). For example, the resonance frequency of the power receiving resonator 21 can be adjusted to a specific frequency by adjusting the capacitance of the capacitor C.

  The power receiving resonator 21 further includes a voltmeter 21 </ b> A that detects a voltage at the inductance L. Hereinafter, the voltage value detected by the voltmeter 21 </ b> A is referred to as a power receiving voltage of the power receiving device 20.

  The power receiving module 22 is a module that receives power. Specifically, as shown in FIG. 3, the power reception module 22 includes a rectifier circuit 22A, a DC / DC converter 22B, a load 22C, and a power storage unit 22D.

  The rectifier circuit 22A converts the DC power transmitted from the power receiving resonator 21 into AC power. The DC / DC converter 22B performs step-up conversion or step-down conversion of power transmitted from the rectifier circuit 22A. The load 22C is operated by the power transmitted by the power transmission device 10, and is, for example, a sensor or a communication device.

  The power storage unit 22D includes a storage battery 22E and a voltmeter 22F. The storage battery 22E stores the power transmitted by the power transmission device 10. The storage battery 22E is, for example, an electric double layer capacitor or a secondary battery. The voltmeter 22F detects the voltage of the storage battery 22E.

  Although FIG. 3 illustrates a case where the power receiving module 22 includes the power storage unit 22D, the embodiment is not limited to this. That is, the power receiving module 22 may not include the power storage unit 22D.

  The communication module 23 is a module that communicates with the power transmission device 10 and the EMS 30. It should be noted that the communication module 23 operates with power transmitted by the power transmission device 10. Specifically, the communication module 23 includes a communication unit 23A and a control unit 23B.

  The communication unit 23A is connected to the power transmission device 10 wirelessly or in a wired manner, transmits a signal to the power transmission device 10 and the EMS 30, and receives a signal from the power transmission device 10 and the EMS 30. For example, as will be described later, the communication unit 23A receives a search signal for searching for the power receiving device 20. The communication unit 23A receives an information request for requesting transmission of information for specifying the type of the power receiving device 20. On the other hand, the communication unit 23A transmits the authentication ID of the power receiving device 20 in response to the search signal. The communication unit 23A transmits information for specifying the type of the power receiving device 20 in response to the information request.

  The communication unit 23 </ b> A transmits the power reception voltage of the power reception device 20 to the EMS 30. In addition, the communication unit 23 </ b> A transmits information indicating the received signal strength of the signal received from the transmission device 10 to the transmission device 10. 23 A of communication parts transmit the information which shows the received signal strength of the signal received from the transmitter 10 to EMS30.

  The control unit 23 </ b> B controls the power reception module 22 and the communication module 23. For example, the control unit 23B supplies appropriate power to the load 22C under the control of the DC / DC converter 22B. Alternatively, the control unit 23B controls the load 22C according to an instruction received from the EMS 30.

  As illustrated in FIG. 1, the EMS 30 includes a communication unit 31, a storage unit 32, and a control unit 33.

  The communication unit 31 is connected to the power transmission device 10 wirelessly or by wire, and transmits a signal to the power transmission device 10 and receives a signal from the power transmission device 10. In addition, the communication unit 31 is connected to the power receiving device 20 wirelessly or by wire, and transmits a signal to the power receiving device 20 and receives a signal from the power receiving device 20.

  The storage unit 32 stores information acquired via the communication unit 31.

  In the first embodiment, the control unit 33 acquires the power reception voltage of the power reception device 20. Further, the control unit 33 acquires the received signal strength of the signal received by the power receiving device 20 from the power transmitting device 10. Specifically, the communication unit 31 receives a signal indicating the reception voltage of the power reception device 20 and a signal indicating the reception signal strength, and the control unit 33 determines the reception voltage and reception signal strength of the power reception device 20 from the communication unit 31. get.

(Applicable scene)
Hereinafter, application scenes of the power transmission system 100 according to the first embodiment will be described. FIG. 4 is a diagram illustrating an application scene of the power transmission system 100 according to the first embodiment.

  As shown in FIG. 4, in the first embodiment, the power transmission system 100 includes a power transmission device 10, an EMS 30, temperature and humidity sensors 210, 220, 230, human sensors 240, 250, and a display device 260. Prepare. The temperature / humidity sensors 210, 220, 230, the human sensor 240, 250, and the display device 260 are examples of the power receiving device 20. In other words, the power transmission device 10 transmits power to the plurality of power reception devices 20 by a magnetic field resonance method.

  As described above, the magnetic field resonance method has a longer power transmission distance than other power transmission methods. However, in the magnetic field resonance method, the power transmission efficiency changes according to the distance (power transmission distance) between the power transmission device 10 and the power reception device 20. Here, the power transmission efficiency refers to the ratio of the received power of the power receiving device 20 to the transmitted power of the power transmitting device 10. The power transmission distance refers to the distance between the power transmission side resonator 11 and the power reception side resonator 21. Hereinafter, the relationship between the power transmission distance and the power transmission efficiency in the magnetic field resonance method will be described.

  FIG. 5 is a diagram illustrating a relationship between the power transmission distance and the power transmission efficiency according to the first embodiment.

  As shown in FIG. 5, when the distance between the power transmission device 10 and the power reception device 20 is within a predetermined distance, the degree of magnetic coupling between the power transmission side resonator 11 and the power reception side resonator 21 is increased, and the power Transmission efficiency exceeds a predetermined value. The predetermined value is determined according to the setting of the function of the power transmission device 10. Hereinafter, a region where the power transmission efficiency exceeds a predetermined value, that is, a proximity region of the power transmission device 20 in which the power transmission distance is equal to or less than the predetermined distance is referred to as area 1.

  Here, the EMS 30 (control unit 33) estimates the power transmission distance for each of the plurality of power receiving apparatuses 20 based on the power reception voltage of each of the plurality of power receiving apparatuses 20. Alternatively, the EMS 30 (the control unit 33) estimates the power transmission distance for each of the plurality of power receiving devices 20 based on the received signal strength of the communication signal received by each of the plurality of power receiving devices 20 from the power transmitting device 10.

  When the power transmission distance becomes longer than a predetermined value, the power transmission efficiency is lowered due to the weak magnetic coupling between the power transmission side resonator 11 and the power reception side resonator 21. Eventually, when the power transmission distance exceeds the allowable maximum distance stipulated in the guidelines, the received power of the power receiving device 20 becomes close to zero. Here, the area where the power transmission distance exceeds the allowable maximum distance specified in the guideline is referred to as area 3, and the area between area 1 and area 3 is referred to as area 2. The allowable maximum distance is determined according to the setting of the function of the power transmission device 10.

  FIG. 6A is a diagram illustrating an example of a positional relationship between the power transmission device 10 and the power reception device 20 according to the first embodiment. FIG. 6B is a diagram illustrating a power reception voltage of the power reception device 20 according to the first embodiment. In FIG. 6A, the temperature / humidity sensor 210 is located in area 1 and the temperature / humidity sensor 220 is located in area 3.

  As can be seen from FIG. 5, the received power of the power receiving device 20 decreases as the power transmission distance increases. Therefore, as shown in FIG. 6B, the received voltage of the temperature / humidity sensor 220 is smaller than the received voltage of the temperature / humidity sensor 210, and as a result, the received temperature of the temperature / humidity sensor 220 is lower than that of the temperature / humidity sensor 210. Get smaller. That is, since the priority of power supply to the power receiving device 20 is automatically determined according to the power transmission distance, the temperature / humidity sensor 220 may not be able to receive a necessary amount of power.

  Therefore, in the first embodiment, the EMS 30 (control unit 33) sets the resonance frequency of at least one power receiving device 20 among the plurality of power receiving devices 20 based on the power transmission distance estimated for each of the plurality of power receiving devices 20. Control.

  As described above, electric power is transmitted from the power transmission device 10 to the power reception device 20 by adjusting the resonance frequency of the power transmission side resonator 11 and the resonance frequency of the power reception side resonator 21 to a specific frequency. Therefore, in the power receiving device 20 in which the resonance frequency of the power receiving resonator 21 is adjusted to a frequency different from the specific frequency, the power transmission efficiency is reduced and the received power is reduced regardless of the power transmission distance. In the case shown in FIG. 6A, when power is preferentially supplied to the temperature / humidity sensor 220, the EMS 30 adjusts the resonance frequency of the power receiving resonator 21 of the temperature / humidity sensor 210 to a frequency different from the specific frequency. FIG. 7B is a diagram illustrating received voltages of the temperature and humidity sensors 210 and 220 when the resonance frequency of the power receiving resonator 21 of the temperature and humidity sensor 210 is adjusted to a frequency different from the specific frequency. As shown in FIG. 7A, the positional relationship between the power transmission device 10 and the temperature / humidity sensors 210 and 220 is the same as that in FIG. 6A, but the received power (received voltage) of the temperature / humidity sensor 210 is suppressed. As a result, the received power (received voltage) of the temperature / humidity sensor 220 increases.

(Control method)
Hereinafter, a control method according to the first embodiment will be described. FIG. 8 is a flowchart showing the control method according to the first embodiment. Here, the power receiving device 20 is the temperature / humidity sensors 210 and 220 illustrated in FIG. 6A, and the search signal and the authentication ID are transmitted / received to / from the power transmitting device 10 in advance, so that the power receiving device 20 that is the power transmission target. It is assumed that it is authenticated as.

  As illustrated in FIG. 8, in step S <b> 110, the EMS 30 acquires the power reception voltage of each power reception device 20. Specifically, the EMS 30 acquires the power reception voltage of the temperature / humidity sensors 210 and 220 by receiving information indicating the power reception voltage from the temperature / humidity sensors 210 and 220.

  In step S120, the EMS 30 estimates the power transmission distance of each power receiving device 20. Specifically, the EMS 30 estimates the power transmission distance of the temperature / humidity sensors 210 and 220 based on the received voltage of the temperature / humidity sensors 210 and 220.

  In step S <b> 130, the EMS 30 determines whether or not there is a power receiving device 20 that is designated with priority. Here, for example, the temperature / humidity sensor 220 is preferentially designated by the user. If the determination result is YES, the EMS 30 proceeds to the process of step S140. If the determination result is NO, the EMS 30 ends the process.

  In step S <b> 140, the EMS 30 determines whether there is a power receiving device 20 having a shorter power transmission distance than the power receiving device 20 with priority specified. If the determination result is YES, the EMS 30 proceeds to the process of step S150. If the determination result is NO, the EMS 30 ends the process.

  In step S <b> 150, the EMS 30 controls the resonance frequency of the power receiving device 20 that has a shorter power transmission distance than the power receiving device 20 that is designated with priority. Specifically, the EMS 30 adjusts the resonance frequency of the reception-side resonator 21 of the temperature / humidity sensor 210 whose power transmission distance is shorter than that of the temperature / humidity sensor 220 that is preferentially specified to a frequency different from the specific frequency.

  As described above, in the first embodiment, the EMS 30 controls the resonance frequency of at least one power receiving device 20 among the plurality of power receiving devices 20 based on the power transmission distance estimated for each of the plurality of power receiving devices 20. To do. As a result, power can be preferentially transmitted to the power receiving device designated by the user as the power receiving device to which power is to be transmitted, regardless of the power transmission distance.

[Second Embodiment]
Hereinafter, the power transmission system according to the second embodiment will be described. FIG. 9 is a diagram illustrating an example of a positional relationship between the power transmission device and the power reception device according to the second embodiment. Here, description of parts common to the first embodiment will be omitted as appropriate, and differences from the first embodiment will be mainly described.

  In 1st Embodiment, the case where the power receiving apparatus 20 which should transmit power preferentially by the user was demonstrated, for example. On the other hand, 2nd Embodiment demonstrates the case where EMS30 judges the power receiving apparatus 20 which should transmit power preferentially, when the several power receiving apparatus 20 is located in the proximity | contact area of a power transmission apparatus. In the case shown in FIG. 9A-1, the temperature / humidity sensor 210 and the human sensor 250 are both located in the area 1. It is assumed that both the temperature / humidity sensor 210 and the human sensor 250 have a power storage unit 22D, the charging rate of the temperature / humidity sensor 210 is 40%, and the charging rate of the human sensor 250 is 30%.

  As described above, in the magnetic field resonance method, the power transmission efficiency changes according to the power transmission distance. However, the power transmission efficiency decreases as the number of power receiving devices 20 increases. In other words, when the plurality of power receiving devices 20 are all located in the proximity area (area 1) of the power transmitting device 10, the power received by each power receiving device 20 is small because the power transmitted by the power transmitting devices 10 is shared. Become. In such a case, even if one power receiving device 20 should be preferentially supplied with power over the other power receiving devices 20, these power receiving devices 20 share the transmitted power of the power transmitting device 10. Even the power receiving device 20 to which power should be transmitted preferentially over other power receiving devices may not receive the required amount of power.

  Therefore, in the second embodiment, the EMS 30 (control unit 33) further acquires information indicating whether or not each of the plurality of power receiving devices 20 has the storage battery 22E, and the plurality of power receiving devices 20 are all When the power transmission efficiency of the power transmission device 10 is located in the proximity region of the power transmission device that exceeds a predetermined value, the resonance frequency of the power reception device 20 including the storage battery 22E is controlled to be different from the resonance frequency of the power transmission device 10.

  For example, when the power receiving device 20 having the storage battery 22E and the power feeding device 20 not having the storage battery 22E are located in the area 1, the EMS 30 determines the resonance frequency of the power receiving resonator 21 of the power receiving device 20 having the storage battery 22E, It adjusts so that it may become a frequency different from the specific frequency which is the resonant frequency of the power transmission side resonator 11. FIG. That is, since the power receiving device 20 having the storage battery 22E can operate with the electric power stored in the storage battery 22E, the power receiving device that does not have the storage battery 22E is suppressed by suppressing the power reception of the power receiving device 20 having the storage battery 22E. Power can be transmitted to 20 with priority.

  In the second embodiment, the EMS 30 (control unit 33) further acquires the charging rate of the storage battery 22E for the power receiving device 20 having the storage battery 22E, and the plurality of power receiving devices 20 are all close to the power transmission device 10. When the power receiving device 20 is located, the resonance frequency of the power receiving device 20 having the storage battery 22E and the charging rate exceeding the threshold value is controlled to be different from the resonance frequency of the power transmission device 10.

  For example, in the case shown in FIG. 9A-1, the temperature / humidity sensor 210 and the human sensor 250 are both located in the area 1, and thus share the transmitted power of the power transmission device 10, and each power storage unit 22 </ b> D (storage battery) 22E) is gradually increased. Thereafter, as illustrated in FIG. 9A-2, when it is determined that the charging rate of the temperature / humidity sensor 210 exceeds a threshold value (for example, 80%), the EMS 30 determines the resonance frequency of the temperature / humidity sensor 210. The temperature / humidity sensor 210 is suppressed in receiving power by adjusting the frequency to be different from the resonance frequency. Thus, after the temperature / humidity sensor 210 has accumulated a sufficient amount of power, the power is preferentially transmitted to the human sensor 250 as shown in FIG. The time until the charging rate reaches the threshold value can be shortened.

(Control method)
Hereinafter, a control method according to the second embodiment will be described. FIG. 10 is a flowchart showing a control method according to the second embodiment. Here, the power receiving device 20 is a temperature / humidity sensor 210 and a human sensor 250 shown in FIG. 9A-1, and a search signal and an authentication ID are transmitted / received to / from the power transmitting device 10 in advance, thereby transmitting power. Assume that the target power receiving apparatus 20 is authenticated.

  As illustrated in FIG. 10, in step S <b> 210, the EMS 30 acquires the power reception voltage of each power reception device 20. Specifically, the EMS 30 acquires the received voltage of the temperature / humidity sensor 210 and the human sensor 250 by receiving information indicating the received voltage from the temperature / humidity sensor 210 and the human sensor 250.

  In step S220, the EMS 30 estimates the power transmission distance of each power receiving device 20. Specifically, the EMS 30 estimates the power transmission distance of the temperature / humidity sensor 210 and the human sensor 250 based on the received voltage of the temperature / humidity sensor 210 and the human sensor 250.

  In step S230, the EMS 30 determines whether or not the power receiving device 20 is located in the proximity region (area 1) of the power transmitting device 10. If the determination result is YES, the EMS 30 proceeds to the process of step S240. If the determination result is NO, the EMS 30 ends the process.

  In step S240, the EMS 30 specifies the power receiving device 20 having the storage battery 22E. Specifically, the presence or absence of the storage battery 22E is determined based on information indicating the type of the power receiving device 20 that has been acquired from each power receiving device 20 in advance.

  In step S250, EMS30 acquires the charging rate of the power receiving apparatus 20 which has the storage battery 22E. In the case shown in FIG. 9A-1, the charging rate of the temperature / humidity sensor 210 is 40%, and the charging rate of the human sensor 250 is 30%.

  In step S260, the EMS 30 determines whether there is the power receiving device 20 in which the charging rate of the storage battery 22E exceeds the threshold value. The threshold value is a value set by the user, for example, and is a value indicating whether or not the storage battery 22E has accumulated enough power so that the operation can be continued even if the power reception device 20 is suppressed in receiving power. If the determination result is YES, the EMS 30 proceeds to the process of step S270. If the determination result is NO, the EMS 30 ends the process. In the case illustrated in FIG. 9A-1, when the threshold value is 80%, the charging rates of the temperature / humidity sensor 210 and the human sensor 250 are both less than the threshold value, and thus the EMS 30 ends the process. On the other hand, in the case shown in FIG. 9 (a-1), since the charging rate of the temperature / humidity sensor 210 has reached the threshold value, the EMS 30 proceeds to the process of step S270.

  In step S270, the EMS 30 controls the resonance frequency of the power receiving device 20 in which the charging rate of the storage battery 22E exceeds the threshold value. In the case illustrated in FIG. 9A-1, the EMS 30 adjusts the resonance frequency of the reception-side resonator 21 of the temperature / humidity sensor 210 to a frequency different from the specific frequency. As a result, power reception suppression is performed on the temperature / humidity sensor 210, and power is preferentially transmitted to the human sensor 250 where the charging rate of the storage battery 22E has not reached the threshold value.

[Third Embodiment]
Hereinafter, the power transmission system according to the third embodiment will be described. FIGS. 11-12 is a figure which shows the example of the positional relationship of the power transmission apparatus and power receiving apparatus which concern on 3rd Embodiment. Here, description of parts common to the second embodiment will be omitted as appropriate, and differences from the second embodiment will be mainly described.

  In 2nd Embodiment, when the several power receiving apparatus 20 was located in the proximity | contact area of a power transmission apparatus, the case where EMS30 judged the power receiving apparatus 20 which should transmit electric power preferentially was demonstrated. On the other hand, in the third embodiment, when the power receiving device 20 located near the power transmitting device 10 and the power receiving device 20 located away from the power transmitting device 10 exist, the EMS 30 is preferentially transmitted power. A case where the power receiving device 20 to be determined is determined will be described.

  In the third embodiment, when there is a power receiving device 20 having a storage battery 22E and a power transmission distance longer than that of the power receiving device 20 having a charging rate exceeding the threshold, among the plurality of power receiving devices 20 EMS30. (Control part 33) has storage battery 22E, and controls the resonance frequency of power receiving device 20 in which a charging rate exceeds a threshold so that it may become a frequency different from the resonance frequency of power transmission device 10.

  For example, in the case shown in FIG. 11A, the temperature / humidity sensor 210 is located in the area 1 and the temperature / humidity sensor 220 is located in the area 3. The temperature / humidity sensor 210 has a power storage unit 22D, and the charging rate of the storage battery 22E is 80%. On the other hand, the temperature / humidity sensor 220 does not have the power storage unit 22D. In such a case, the EMS 30 adjusts the resonance frequency of the power reception side resonator 21 of the temperature / humidity sensor 210 to be different from the specific frequency that is the resonance frequency of the power transmission side resonator 11. That is, since the temperature / humidity sensor 210 can operate with the electric power stored in the storage battery 22E, the power transmission distance is longer than that of the temperature / humidity sensor 210 by suppressing power reception by the temperature / humidity sensor 210, and the storage battery Power can be preferentially transmitted to the temperature / humidity sensor 220 that does not have 22E.

  On the other hand, in the case shown in FIG. 11B, the temperature / humidity sensor 220 located in the area 3 has the power storage unit 22D, but the charging rate of the storage battery 22E is 40%, which is lower than the threshold value. Similarly, in such a case, the EMS 30 adjusts the resonance frequency of the power reception side resonator 21 of the temperature / humidity sensor 210 to be different from the specific frequency that is the resonance frequency of the power transmission side resonator 11. That is, by suppressing power reception by the temperature / humidity sensor 210, power can be preferentially transmitted to the temperature / humidity sensor 220, and the time until the charging rate of the temperature / humidity sensor 220 reaches the threshold value can be shortened.

  In the case shown in FIG. 12 (a-1), the temperature / humidity sensor 210 located in the area 1 has the power storage unit 22D, but the charging rate of the storage battery 22E is 40%, which is lower than the threshold value. In such a case, regardless of whether or not the temperature / humidity sensor 220 located in the area 3 includes the power storage unit 22D, the EMS 30 preferentially powers the temperature / humidity sensor 210 according to the power transmission distance. Is transmitted. Thereafter, as shown in FIG. 12 (a-2), when the charging rate of the storage battery 22E exceeds the threshold value, the EMS 30 performs power reception suppression on the temperature / humidity sensor 210 and prioritizes the temperature / humidity sensor 220. Power is transmitted.

(Control method)
Hereinafter, a control method according to the third embodiment will be described. FIG. 13 is a flowchart showing a control method according to the third embodiment. Here, the power receiving device 20 is the temperature / humidity sensor 210 and the temperature / humidity sensor 220 illustrated in FIG. 11A, and the search signal and the authentication ID are transmitted / received to / from the power transmission device 10 in advance, and the power transmission target is received. Assume that the power receiving apparatus 20 is authenticated.

  As illustrated in FIG. 13, in step S <b> 310, the EMS 30 acquires the power reception voltage of each power reception device 20. Specifically, the EMS 30 acquires the received voltage of the temperature / humidity sensor 210 and the temperature / humidity sensor 220 by receiving information indicating the received voltage from the temperature / humidity sensor 210 and the temperature / humidity sensor 220.

  In step S320, the EMS 30 estimates the power transmission distance of each power receiving device 20. Specifically, the EMS 30 estimates the power transmission distance of the temperature / humidity sensor 210 and the temperature / humidity sensor 220 based on the received voltage of the temperature / humidity sensor 210 and the temperature / humidity sensor 220. In the case shown in FIG. 11A, the temperature / humidity sensor 210 is located in the area 1 and the temperature / humidity sensor 220 is located in the area 3 from the power transmission distance estimated for the temperature / humidity sensor 210 and the temperature / humidity sensor 220. Is identified.

  In step S330, the EMS 30 specifies the power receiving device 20 having the storage battery 22E. Specifically, the presence or absence of the storage battery 22E is determined based on information indicating the type of the power receiving device 20 that has been acquired from each power receiving device 20 in advance. In the case shown in FIG. 11A, the temperature / humidity sensor 210 has a charging rate of the storage battery 22E, and the temperature / humidity sensor 220 does not have the storage battery 22E.

  In step S340, EMS30 acquires the charging rate of the power receiving apparatus 20 which has the storage battery 22E. In the case shown in FIG. 11A, the charging rate of the temperature / humidity sensor 210 is 80%.

  In step S350, the EMS 30 determines whether or not there is the power receiving device 20 in which the charging rate of the storage battery 22E exceeds the threshold value. The threshold value is a value set by the user, for example, and is a value indicating whether or not the storage battery 22E has accumulated enough power so that the operation can be continued even if the power reception device 20 is suppressed in receiving power. If the determination result is YES, the EMS 30 proceeds to the process of step S360. If the determination result is NO, the EMS 30 ends the process. In the case shown in FIG. 11A, when the threshold value is 80%, the charging rate of the temperature / humidity sensor 210 has reached the threshold value, so the EMS 30 proceeds to the process of step S360.

  In step S360, the EMS 30 determines whether or not there is a power receiving device having a longer power transmission distance than the power receiving device 20 in which the charging rate of the storage battery 22E exceeds the threshold value. If the determination result is YES, the EMS 30 proceeds to the process of step S370. If the determination result is NO, the EMS 30 ends the process. In the case shown in FIG. 11A, the temperature / humidity sensor 220 is located in the area 3, and the power transmission distance is longer than that of the temperature / humidity sensor 210 located in the area 1, and therefore the EMS 30 proceeds to the process of step S370. In step S370, the EMS 30 controls the resonance frequency of the power receiving device 20 in which the charging rate of the storage battery 22E exceeds the threshold value. In the case shown in FIG. 11A, the EMS 30 adjusts the resonance frequency of the reception-side resonator 21 of the temperature / humidity sensor 210 to a frequency different from the specific frequency. As a result, power reception suppression is performed for the temperature / humidity sensor 210, and power is preferentially transmitted to the temperature / humidity sensor 220 that does not have the storage battery 22E.

[Other Embodiments]
Although the present invention has been described with reference to the above-described embodiments, it should not be understood that the descriptions and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  In the embodiment, the case where the control unit that controls the transmission power of the power transmission device 10 is provided in the EMS 30 is illustrated. However, the embodiment is not limited to this. The control part which controls the transmitted power of the power transmission apparatus 10 may be provided in the communication module (control part 13B) of the power transmission apparatus 10, for example.

  In the embodiment, the resonance frequencies of the plurality of power reception devices 20 are adjusted to a state (resonance state) that matches the resonance frequency of the power transmission device 10 in the initial state, and the resonance frequencies of the power reception devices 20 that are targets of power reception suppression are It demonstrated as what is adjusted to the state (non-resonant state) different from the resonant frequency of the power transmission apparatus 10. FIG. However, the embodiment is not limited to this. The resonance frequencies of the plurality of power receiving devices 20 may be adjusted to the non-resonant state in the initial state, and the resonance frequencies of the power receiving devices 20 to which power should be transmitted preferentially may be adjusted to the non-resonant state.

  Although not specifically mentioned in the embodiment, a program for causing a computer to execute each process performed by the power transmission device 10 and the power reception device 20 may be provided. The program may be recorded on a computer readable medium. If a computer-readable medium is used, a program can be installed in the computer. Here, the computer-readable medium on which the program is recorded may be a non-transitory recording medium. The non-transitory recording medium is not particularly limited, but may be a recording medium such as a CD-ROM or a DVD-ROM.

  Alternatively, a chip configured by a memory that stores a program for executing each process performed by the power transmitting device 10 and the power receiving device 20 and a processor that executes the program stored in the memory may be provided.

  DESCRIPTION OF SYMBOLS 10 ... Power transmission apparatus, 11 ... Power transmission side resonator, 11A ... Voltmeter, 12 ... Power transmission module, 12A ... Oscillation circuit, 12B ... Power supply, 13 ... Communication module, 13A ... Communication part, 13B ... Control part, 20 ... Power receiving apparatus , 21 ... Receiving side resonator, 21A ... Voltmeter, 22 ... Power receiving module, 22A ... Rectifier circuit, 22B ... DC / DC converter, 22C ... Load, 22D ... Power storage unit, 22E ... Storage battery, 23 ... Communication module, 23A ... Communication unit, 23B ... control unit, 30 ... EMS, 31 ... communication unit, 32 ... storage unit, 33 ... control unit

Claims (10)

A control device used in a power transmission system that transmits power from a power transmission device to a plurality of power reception devices by a magnetic resonance method,
For each of the plurality of power receiving devices, a control unit that estimates a power transmission distance that is a distance from the power transmitting device,
The control unit, based on the power transmission distance estimated for each of the plurality of power receiving devices, among the plurality of power receiving devices, at least one power receiving to be adjusted to a resonance frequency different from the resonance frequency of the power transmission device. A control device characterized by identifying a device and controlling a resonance frequency of the identified power receiving device.   The control unit acquires a power reception voltage of each of the plurality of power reception devices, and estimates the power transmission distance for each of the plurality of power reception devices based on the acquired power reception voltage. Item 2. The control device according to Item 1.   When the power transmission device transmits a communication signal and each of the plurality of power receiving devices receives the communication signal, the control unit obtains a received signal strength of the communication signal received by each of the plurality of power receiving devices. The control device according to claim 1, wherein the power transmission distance is estimated for each of a plurality of power receiving devices based on the acquired received signal strength.   When a power receiving device to which power is to be transmitted preferentially is designated from among the plurality of power receiving devices, the control unit is configured to have a resonance frequency of the power receiving device that has a shorter power transmission distance than the designated power receiving device. The control device according to claim 1, wherein the control device is controlled to have a frequency different from a resonance frequency of the power transmission device.   The control unit further acquires, for each of the plurality of power receiving devices, information indicating whether or not the battery has a storage battery, and the power transmission efficiency of the power transmitting device exceeds a predetermined value for each of the plurality of power receiving devices. 2. The control device according to claim 1, wherein the control device controls the resonance frequency of the power reception device having the storage battery to be a frequency different from the resonance frequency of the power transmission device when located in a proximity region of the power transmission device. .   The control unit further acquires a charge rate of the storage battery for the power receiving device having the storage battery, and has the storage battery when the plurality of power receiving devices are all located in a proximity region of the power transmission device, and The control device according to claim 5, wherein the control unit controls the resonance frequency of the power receiving device whose charging rate exceeds a threshold to be a frequency different from the resonance frequency of the power transmission device.   When there is a power receiving device that has the storage battery in the plurality of power receiving devices and has a longer power transmission distance than a power receiving device in which the charging rate exceeds a threshold value, the control unit The control device according to claim 6, further comprising: controlling a resonance frequency of the power receiving device having a charging rate exceeding a threshold value to be a frequency different from the resonance frequency of the power transmission device. A power transmission device used in a power transmission system for transmitting power by a magnetic resonance method,
For each of a plurality of power receiving devices, a control unit that estimates a power transmission distance that is a distance from the power transmitting device,
The control unit, based on the power transmission distance estimated for each of the plurality of power receiving devices, among the plurality of power receiving devices, at least one power receiving to be adjusted to a resonance frequency different from the resonance frequency of the power transmission device. A power transmission device characterized by identifying a device and controlling a resonance frequency of the identified power receiving device. A power transmission system for transmitting power by a magnetic resonance method,
A power transmission device having a power transmission side resonator for transmitting the power;
A plurality of power receiving devices having a power receiving side resonator that receives the power transmitted from the power transmitting device;
For each of the plurality of power receiving devices, a control device that acquires a power transmission distance that is a distance from the power transmitting device,
The control device, based on the power transmission distance for each of the plurality of power receiving devices, among the plurality of power receiving devices, at least one power receiving device to be adjusted to a resonance frequency different from the resonance frequency of the power transmission device And a resonance frequency of the identified power receiving apparatus is controlled. A control method in a control device used in a power transmission system for transmitting power from a power transmission device to a plurality of power reception devices by a magnetic resonance method,
For each of the plurality of power receiving devices, obtaining a power transmission distance that is a distance from the power transmitting device;
Based on the power transmission distance for each of the plurality of power receiving devices , identify and specify at least one power receiving device to be adjusted to a resonance frequency different from the resonance frequency of the power transmission device among the plurality of power receiving devices. Controlling the resonance frequency of the power receiving apparatus .

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