Power transmission equipment

Abstract

To increase the number of power reception devices to which a power transmission device can supply power.SOLUTION: A power transmission device is configured to be movable. The power transmission device includes a power transmission unit and a power transmission control unit. The power transmission unit supplies power to a plurality of power reception devices by contactless power supply. The power transmission control unit divides the plurality of power reception devices into groups based on feedable power of the power transmission device. The power transmission control unit moves the power transmission device to a position where power can be supplied to a group to be supplied with power. The power transmission control unit supplies power to a group to be supplied with power.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a power transmitting device. [Background technology]

[0002] The contactless power supply system disclosed in Patent Document 1 includes a power transmitting device and a power receiving device. The power transmitting device supplies power to the power receiving device by contactless power supply. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6125471 Summary of the Invention [Problem to be solved by the invention]

[0004] When there are multiple power receiving devices, the number of power transmitting devices may need to be increased in order to supply power to all of the power receiving devices. In this case, the increased number of power transmitting devices may increase the cost of the contactless power supply system. [Means for solving the problem]

[0005] Various aspects of the power transmission device for solving the above problems will be described below. [Aspect 1] A mobile power transmission device comprising: a power transmission unit that supplies power to multiple power receiving devices via contactless power supply; and a power transmission control unit that controls the power transmission unit, wherein the power transmission control unit divides the multiple power receiving devices into groups based on the power that the power transmission device can supply, moves the power transmission device to a position where it can supply power to the group that is the target of power supply, and supplies power to the group that is the target of power supply.

[0006] Since the power transmission device is configured to be movable, it can be moved to a position where it can supply power to a group of power receiving devices. By switching the group of power receiving devices, it is possible to supply power to a plurality of power receiving devices divided into groups. Compared to when the power transmission device is located at a fixed position, the number of power receiving devices to which the power transmission device can supply power can be increased. Therefore, it is possible to prevent the number of power transmission devices from increasing.

[0007] [Aspect 2] The power transmitting device according to [Aspect 1], wherein the power transmission control unit divides the plurality of power receiving devices into the groups based on the power that can be supplied by the power transmitting device and the power consumption of each of the plurality of power receiving devices.

[0008] When the power consumption of the power receiving device is large, the power storage device may not be charged even if the power transmitting device supplies power. By grouping the power receiving devices based on the power that the power transmitting device can supply and the power consumption of each of the power receiving devices, the grouping can be performed so that the power storage device can be charged.

[0009] [Aspect 3] The power transmission control unit calculates a power supply time for each group based on the power that can be supplied by the power transmission device, the power consumption of each of the multiple power receiving devices, and the charging rate of the power storage device provided in the power receiving device, so that the charging rate of the power storage device of the power receiving device belonging to the group is equal to or higher than a predetermined threshold, and supplies power to the group to be supplied with power during the power supply time.This is the power transmission device described in [Aspect 1] or [Aspect 2].

[0010] Power can be supplied so that the charge rate of the power storage device is equal to or higher than a threshold value. [Effects of the Invention]

[0011] According to the present invention, it is possible to increase the number of power receiving devices to which a power transmitting device can supply power. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram of a contactless power supply system. [Figure 2] FIG. 2 is a schematic configuration diagram of the contactless power supply system of FIG. [Figure 3] 3 is a flowchart showing control performed by a power transmission control unit in FIG. 2. [Figure 4] FIG. 4 is a schematic diagram showing a frame set set in the flowchart of FIG. 3. DETAILED DESCRIPTION OF THE INVENTION

[0013] An embodiment of a power transmission device will be described. As shown in FIG. 1 , the contactless power transfer system 10 includes a plurality of power receiving devices 11 and a power transmitting device 31. The power transmitting device 31 may be a single device or a plurality of devices. The contactless power transfer system 10 can be used in any location. For example, the contactless power transfer system 10 is used in a factory, a farm, a public facility, or a commercial facility. The contactless power transfer system 10 is a system in which the power transmitting device 31 contactlessly transfers power to the power receiving device 11.

[0014] <Power receiving device> As shown in FIG. 2, the power receiving device 11 includes a power receiving control unit 12. The power receiving control unit 12 includes, for example, a processor 13 and a storage unit 14. The storage unit 14 includes a random access memory (RAM) and a read-only memory (ROM). The storage unit 14 stores program code or instructions configured to cause the processor 13 to execute processing. The storage unit 14, i.e., a computer-readable medium, includes any available medium accessible by a general-purpose or special-purpose computer. The power receiving control unit 12 may be configured by a hardware circuit such as an application-specific integrated circuit (ASIC) or a field-programmable gate array (FPGA). The power receiving control unit 12, which is a processing circuit, may include one or more processors operating according to a computer program, one or more hardware circuits such as an ASIC or an FPGA, or a combination thereof.

[0015] The power receiving device 11 includes a power receiving antenna 15. The power receiving antenna 15 is configured to receive a power transmission signal W1. The power receiving antenna 15 is, for example, a monopole antenna, a dipole antenna, a helical antenna, a parabolic antenna, a microstrip antenna, or an antenna array including multiple antennas. The power receiving antenna 15 converts the power transmission signal W1 into AC power, which is an electrical signal. The power transmission signal W1 is transmitted as a wireless signal from the power transmitting device 31 to the power receiving device 11. The power transmission signal W1 includes microwaves. In this embodiment, microwave-based contactless power supply is performed, but contactless power supply may be performed by any method. For example, contactless power supply may be laser-based or ultrasonic-based.

[0016] The power receiving device 11 includes a receiving power converter 16. The receiving power converter 16 converts AC power output from the power receiving antenna 15 into receiving power. The receiving power is power that the power receiving device 11 obtains from the power transmission signal W1. The receiving power is DC power. The specific form of the receiving power converter 16 is arbitrary, but may include, for example, a rectifier circuit or a smoothing circuit.

[0017] The power receiving device 11 includes a power storage device 17. The power storage device 17 is a power source for the power receiving device 11. For example, a secondary battery such as a lithium ion battery or a capacitor can be used as the power storage device 17. The power storage device 17 stores a part or all of the received power converted by the received power conversion unit 16. In this way, power is supplied to the power receiving device 11 by the power transmission signal W1.

[0018] The power receiving device 11 includes a detection unit 18. The detection unit 18 detects the charging rate of the power storage device 17. The detection unit 18 is, for example, a battery management system. The detection unit 18 includes a sensor for detecting the charging rate of the power storage device 17 and a derivation unit for deriving the charging rate of the power storage device 17 from the detection result of the sensor. The derivation unit can derive the charging rate of the power storage device 17 from the detection result of the sensor. The charging rate can be derived by any method, but examples include a method using a correlation between the open circuit voltage and charging rate of the power storage device 17, a current integration method, or a combination of these.

[0019] The power receiving device 11 includes a communication antenna 19. The communication antenna 19 is configured to be able to transmit and receive a communication signal W2. The communication signal W2 is transmitted from the power transmitting device 31. The communication antenna 19 and the power receiving antenna 15 may be provided separately, or the power receiving antenna 15 may also serve as the communication antenna 19.

[0020] The power receiving device 11 includes a power receiving communication unit 20. The power receiving communication unit 20 demodulates a communication signal W2 received by a communication antenna 19. The power receiving communication unit 20 outputs data obtained by the demodulation to the power receiving control unit 12. The power receiving communication unit 20 transmits the communication signal W2 modulated based on the data output by the power receiving control unit 12 from the communication antenna 19. The power transmitting device 31 and the power receiving device 11 are configured to be able to communicate with each other via the communication signal W2.

[0021] The power receiving device 11 includes a position detection unit 21. The position detection unit 21 detects the position of the power receiving device 11. The position of the power receiving device 11 may be coordinates in an absolute coordinate system that represents an absolute position. The position of the power receiving device 11 may be coordinates in a relative coordinate system that represents a relative position with respect to the power transmitting device 31. The position detection unit 21 of this embodiment is a satellite navigation device. The position detection unit 21 receives satellite signals transmitted from GNSS (Global Navigation Satellite System) satellites and detects the position using the satellite signals. When a satellite navigation device is used as the position detection unit 21, the position of the power receiving device 11 is expressed, for example, by longitude and latitude.

[0022] The power receiving device 11 may be any device that consumes power from the power storage device 17 to operate. The power receiving device 11 is, for example, a sensor that consumes power from the power storage device 17 to operate, or a communication terminal. <Power transmission device> The power transmission device 31 includes a power transmission control unit 32. The power transmission control unit 32 includes, for example, a processor 33 and a memory unit 34. The memory unit 34 includes RAM and ROM. The memory unit 34 stores program code or instructions configured to cause the processor 33 to execute processing. The memory unit 34, i.e., the computer-readable medium, includes any available medium accessible by a general-purpose or special-purpose computer. The power transmission control unit 32 may be configured by a hardware circuit such as an ASIC or FPGA. The power transmission control unit 32, which is a processing circuit, may include one or more processors operating according to a computer program, one or more hardware circuits such as an ASIC or FPGA, or a combination thereof.

[0023] The power transmitting device 31 includes a transmission power converter 35. The transmission power converter 35 converts power supplied from a power source into an electrical signal at a transmission frequency. The power source is, for example, a power storage device or a power grid. If the power source is a power grid, the power transmitting device 31 may include a converter that converts AC power supplied from the power grid into DC power. The transmission power converter 35 includes a circuit including a switching element, such as a high-frequency amplifier circuit or a chopper circuit. Through control of the switching element of the transmission power converter 35, the transmission power converter 35 outputs the DC power supplied from the power source as an AC power electrical signal. In other words, the transmission power converter 35 functions as a DC / AC inverter. The transmission power converter 35 is controlled by the power transmission control unit 32.

[0024] The power transmitting device 31 includes a power transmitting antenna 36. The power transmitting antenna 36 converts an electrical signal output from the power transmitting power converter 35 into a power transmission signal W1 and transmits the signal. The power transmitting antenna 36 is, for example, a monopole antenna, a dipole antenna, a helical antenna, a parabolic antenna, a microstrip antenna, or a phased array antenna including multiple antennas. The power transmitting power converter 35 and the power transmitting antenna 36 constitute a power transmitting unit.

[0025] The power transmitting device 31 includes a communication antenna 37. The communication antenna 37 is configured to be able to transmit and receive a communication signal W2. The communication antenna 37 and the power transmitting antenna 36 may be provided separately, or the power transmitting antenna 36 may also serve as the communication antenna 37.

[0026] The power transmitting device 31 includes a power transmitting communication unit 38. The power transmitting communication unit 38 demodulates a communication signal W2 received by the power transmitting antenna 36. The power transmitting communication unit 38 outputs the data obtained by the demodulation to the power transmitting control unit 32. The power transmitting communication unit 38 transmits the communication signal W2 modulated based on the data output by the power transmitting control unit 32 from the communication antenna 37. The power transmitting communication unit 38 and the power receiving communication unit 20 are arranged to be able to communicate with each other, so that the power transmitting device 31 and the multiple power receiving devices 11 form a wireless sensor network.

[0027] The power transmission device 31 includes a moving device 39. The moving device 39 is an actuator that moves the power transmission device 31. The moving device 39 includes, for example, wheels, a motor that rotates the wheels, and a motor driver. The power transmission control unit 32 moves the power transmission device 31 by controlling the moving device 39. The moving device 39 may move along a predetermined trajectory. The moving device 39 may move along an arbitrary route while recognizing its position on a map by self-location estimation. In other words, it is sufficient for the moving device 39 to be able to move the power transmission device 31. The power transmission device 31 is configured to be movable by the moving device 39. The moving device 39 may be a flying device that moves the power transmission device 31 by flying it.

[0028] The moving device 39 may rotate the power transmitting device 31 around a rotation axis. The range in which the power transmitting device 31 can rotate may be less than 360°. In this case, the moving device 39 includes, for example, a motor and a transmission. The movement of the power transmitting device 31 includes a change in the orientation of the power transmitting device 31. In other words, the movement of the power transmitting device 31 may be such that at least one of the relative position between the power transmitting device 31 and the power receiving device 11 and the relative angle between the power transmitting device 31 and the power receiving device 11 changes.

[0029] <Control performed by the power transmission control unit> The power transmission control unit 32 executes the following control at a predetermined control period. As shown in FIG. 3, in step S1, the power transmission control unit 32 acquires power reception information from each of the multiple power receiving devices 11. The power reception information includes charging information indicating the charging rate of the power storage device 17, location information indicating the location of the power receiving device 11, and identification information. The identification information is an ID code for identifying the power receiving device 11 and is different for each power receiving device 11. The power reception information can be acquired by a communication signal W2. The power transmission control unit 32 may acquire power transmission device location information indicating the location of the power transmitting device 31. The power transmitting device location information may be acquired by self-location estimation. If the location information is information indicating the relative position between the power receiving device 11 and the power transmitting device 31, the position of the power transmitting device 31 may be calculated from the location information.

[0030] Next, in step S2, the power transmission control unit 32 groups the multiple power receiving devices 11. The power transmission control unit 32 performs grouping based on the charging information and the location information. As a result, the multiple power receiving devices 11 are divided into groups. An example of control performed by the power transmission control unit 32 when performing grouping will be described.

[0031] As shown in FIG. 1, the power transmission control unit 32 sets a power supplyable range A1. The power supplyable range A1 is, for example, a range determined based on the power transmission device 31. Therefore, when the power transmission device 31 moves, the power supplyable range A1 also moves following the power transmission device 31. The power supplyable range A1 is a predetermined range within which the power transmission device 31 can supply power stably. The farther the power receiving device 11 is located from the power transmission device 31, the less likely it is to supply power. Therefore, the power supplyable range A1 is set so that the power receiving device 11 located excessively far from the power transmission device 31 is excluded from the power supplyable range A1. The power transmission control unit 32 recognizes the power receiving device 11 located within the power supplyable range A1 from the position information.

[0032] The power transmission control unit 32 calculates the power consumption [Wh] for each power receiving device 11 from the charging information and the identification information. For example, the power transmission control unit 32 calculates the power consumption for each power receiving device 11 based on the elapsed time and the amount of decrease in the charging rate of the power storage device 17. The power transmission control unit 32 calculates the supplyable power [Wh] for each power receiving device 11. The supplyable power is determined, for example, by the positional relationship between the power transmission device 31 and the power receiving device 11 and the number of power receiving devices 11 present within the power supply range A1. The supplyable power is the received power that the power receiving device 11 can obtain when power is supplied to the power receiving device 11.

[0033] The power transmission control unit 32 groups the power receiving devices 11 that are present within the power supply range A1 and whose power consumption is lower than the power that can be supplied as group A. The power transmission control unit 32 may group the power receiving devices 11 that are present within the power supply range A1 and whose power consumption is lower than the power that can be supplied by a predetermined value or more. Any value can be set as the predetermined value. As described above, the power transmission control unit 32 groups the power receiving devices 11 based on the power that can be supplied by the power transmitting device 31 and the power consumption of each of the multiple power receiving devices 11. In the following description, the power receiving devices 11 that belong to group A will be referred to as power receiving devices 11A as appropriate.

[0034] The power transmission control unit 32 groups the power receiving devices 11 that do not belong to group A. The grouping of the power receiving devices 11 that do not belong to group A can be performed in the same manner as for group A. When grouping the power receiving devices 11 that do not belong to group A, the grouping can be performed by assuming a power supply range A1 when the power transmitting device 31 moves to supply power. Furthermore, when grouping the power receiving devices 11 that do not belong to group A, the grouping is performed, for example, so as to reduce the amount of movement of the power transmitting device 31. Because the power transmitting device 31 supplies power to all the power receiving devices 11 by moving using the moving device 39, power can be supplied more efficiently when the amount of movement of the power transmitting device 31 is reduced. The power transmission control unit 32 performs grouping based on the position information so as to reduce the amount of movement of the power transmitting device 31. The amount of movement is the total amount of movement of the power transmitting device 31 until power supply to all the power receiving devices 11 is completed.

[0035] In the example shown in Fig. 1, the power receiving devices 11 that do not belong to group A are divided into group B and group C. In the example shown in Fig. 1, the grouping is performed such that group B and group C are separated with group A in between. In the following description, the power receiving device 11 that belongs to group B will be referred to as power receiving device 11B, and the power receiving device 11 that belongs to group C will be referred to as power receiving device 11C, as appropriate.

[0036] As shown in FIG. 3, next, in step S3, the power transmission control unit 32 sets a frame set. As shown in FIG. 4 , a frame set is a power supply time set for each of groups A, B, and C. The power transmission control unit 32 sets the frame set by calculating the power supply time for each of groups A, B, and C. The power supply time is calculated, for example, so that the charging rates of the power storage devices 17 of all power receiving devices 11 belonging to the same group are equal to or higher than a predetermined threshold when power is supplied during the power supply time. The threshold is set so that the charging rates of the power storage devices 17 do not become excessively low. The threshold is set, for example, based on the maximum capacity of the power storage devices 17 and the power required for the operation of the power receiving devices 11. The power supply time for each of groups A, B, and C can be calculated, for example, based on the supplyable power of the power transmitting device 31, the power consumption of each of the multiple power receiving devices 11, and the charging rates of the power storage devices 17. In detail, the power supply time for each of groups A, B, and C can be calculated based on the charging power, which is the supplyable power of the power transmitting device 31 minus the power consumption, and the charging rates of the power storage devices 17. The greater the charging power, the more likely the charging rate of the power storage device 17 is to increase. The lower the charging rate of the power storage device 17, the less likely the charging rate of the power storage device 17 is to exceed the threshold. Therefore, the power transmission control unit 32 calculates the power supply time based on the charging power and the charging rate of the power storage device 17 so that the charging rate of the power storage device 17 is equal to or greater than the threshold. The greater the charging power, the shorter the power supply time. The lower the charging rate of the power storage device 17, the longer the power supply time. The power transmission control unit 32 calculates the power supply time using, for example, a trained model that has been trained by supervised learning. The trained model is a regression model. The trained model is generated, for example, by associating the charging power of the power receiving device 11 belonging to the same group and the charging rate of the power storage device 17 with the time required for the charging rate of the power storage device 17 to exceed the threshold, as training data. The trained model is stored, for example, in the storage unit 34 or an auxiliary storage device provided in the power transmission device 31. The trained model may be updated every time the power transmitting device 31 supplies power to the power receiving device 11.

[0037] 3, next, in step S4, the power transmitting device 31 supplies power to group A. Power is supplied to group A in accordance with a frame set. In step S4, group A is the group to be supplied with power.

[0038] Next, in step S5, the power transmission control unit 32 determines whether or not there is a power receiving device 11 that is not being fed power. More specifically, if one cycle is defined as the time when power is fed to all the power receiving devices 11, the power transmission control unit 32 determines whether or not there is a power receiving device 11 to which power has not been fed in the current cycle. In other words, step S5 is a determination as to whether or not one cycle has been completed. In this embodiment, since the multiple power receiving devices 11 are divided into three groups A, B, and C, the determination in step S5 becomes negative when power feeding to the three groups A, B, and C is completed. If the determination result in step S5 is negative, the power transmission control unit 32 returns to step S1 and starts the next cycle. If the determination result in step S5 is positive, the power transmission control unit 32 performs the process of step S6.

[0039] In step S6, the power transmission control unit 32 performs regrouping. Regrouping is grouping the power receiving devices 11 to which power feeding has not been completed. If the power receiving device 11 moves after the grouping in step S2, there is a risk that power feeding to the power receiving device 11 will not be possible. Therefore, regrouping is performed to prevent the occurrence of a power receiving device 11 to which power feeding cannot be performed. For example, suppose that one power receiving device 11A moves out of the power feedable range A1 after the grouping in step S2. In this case, regrouping is performed so that the power receiving device 11A belongs to group B or group C.

[0040] Next, in step S7, the power transmission control unit 32 controls the movement device 39 to move the power transmission device 31 to a position where power can be supplied to the group to be supplied with power. If the group to be supplied with power is group B, the power transmission control unit 32 moves the power transmission device 31 to a position where power can be supplied to the power receiving device 11B efficiently. If the group to be supplied with power is group C, the power transmission control unit 32 moves the power transmission device 31 to a position where power can be supplied to the power receiving device 11C efficiently. The group to be supplied with power is, for example, a group to which power supply has not been completed within one period and which is closest to the current position of the power transmission device 31.

[0041] Next, in step S8, the power transmission control unit 32 supplies power to the group to be supplied with power. The power supply to the group to be supplied with power is performed in accordance with the frame set. After completing the process of step S8, the power transmission control unit 32 returns to step S5. As a result, power is supplied sequentially to the power receiving device 11B and the power receiving device 11C.

[0042] [Operation of this embodiment] The power transmitting device 31 has a set power supply range A1, so the range within which the power transmitting device 31 can supply power is limited. If the power transmitting device 31 is placed in a fixed location, the power supply range A1 is also a fixed range, so power can be supplied only to a limited number of power receiving devices 11. In contrast, the power transmitting device 31 of the present embodiment is configured to be movable, so it can be moved to a position where it can supply power to a group of power receiving devices 11.

[0043] [Effects of this embodiment] (1) The power transmission control unit 32 can switch the group to which power is to be supplied, thereby supplying power to a plurality of power receiving devices 11 divided into groups A, B, and C. Compared to when the power transmitting device 31 is placed at a fixed position, the number of power receiving devices 11 to which the power transmitting device 31 can supply power can be increased. Therefore, an increase in the number of power transmitting devices 31 can be suppressed.

[0044] (2) The power transmission control unit 32 groups the power receiving devices 11 based on the power that the power transmitting device 31 can supply and the power consumption of each of the power receiving devices 11. If the power consumption of the power receiving device 11 is large, the power transmitting device 31 may not be able to charge the power storage device 17 even if it supplies power. By grouping based on the power that the power transmitting device 31 can supply and the power consumption of each of the multiple power receiving devices 11, the grouping can be performed so that the power storage device 17 can be charged.

[0045] (3) The power transmission control unit 32 calculates the power supply time for each of the groups A, B, and C so that the charge rates of the power storage devices 17 of the power receiving devices 11 belonging to the groups A, B, and C are equal to or greater than a threshold. When supplying power to a group to be supplied with power, the power transmission control unit 32 supplies power for the calculated power supply time. This allows the charge rates of the power storage devices 17 of the power receiving devices 11 to be equal to or greater than the threshold.

[0046] (4) Since the power transmission device 31 is configured to be movable, it can move to a position where power supply is efficient and supply power to the power reception device 11. Therefore, the capacity of the power storage device 17 of the power reception device 11 can be reduced.

[0047] [Example of change] The embodiment can be modified as follows: The embodiment and the following modifications can be combined with each other to the extent that they are not technically inconsistent.

[0048] The power transmission control unit 32 may continue supplying power until the charge rate of the power storage device 17 of the power receiving device 11 belonging to the group to which power is to be supplied reaches or exceeds a threshold. That is, instead of the power supply time, the charge rate of the power storage device 17 may be used as a condition for ending power supply.

[0049] When grouping a plurality of power receiving devices 11, the power transmission control unit 32 may set only the group to be supplied with power. In the embodiment, in step S2, only group A may be set, and groups B and C may not be set. In this case, the power supply time for group A is set as a frame set. Then, power is supplied to group A during the power supply time. After power supply to group A is completed, a group to be supplied with power is set starting from the power receiving devices 11 that do not belong to group A. Then, the power transmission control unit 32 sets the frame set, moves the power transmitting device 31 to a position where power can be supplied to the group to be supplied with power, and supplies power. In this way, the power transmission control unit 32 may supply power to all of the power receiving devices 11 by repeating the process of setting the group to be supplied with power, setting the frame set, moving the frame set, and supplying power.

[0050] The power transmission control unit 32 may perform grouping based on the power supply range A1. In this embodiment, in step S2, the power receiving devices 11 present within the power supply range A1 may be grouped as group A. The power supply range A1 can be said to be a range set based on the power that the power transmitting device 31 can supply. Therefore, even in this case, the power transmission control unit 32 divides the multiple power receiving devices 11 into groups based on the power that the power transmitting device 31 can supply.

[0051] The power transmission control unit 32 may perform grouping based on the supplyable power of the power transmission device 31 and the power consumption of each of the multiple power receiving devices 11. In this embodiment, in step S2, the power receiving devices 11 whose power consumption is lower than the supplyable power may be grouped as group A. Furthermore, the power transmission control unit 32 may group the power receiving devices 11 whose power consumption is lower than the supplyable power by a predetermined value or more.

[0052] The contactless power transfer system 10 may include a camera. In this case, the camera is positioned so that it can capture images of both the power receiving device 11 and the power transmitting device 31. The power transmission control unit 32 may recognize the relative positions of the power receiving device 11 and the power transmitting device 31 from image data captured by the camera. In this case, the power receiving device 11 does not need to include the position detection unit 21.

[0053] After regrouping, the power transmission control unit 32 may recalculate the power supply time. [Explanation of symbols]

[0054] A, B, C...Group 11...Power receiving device 17...Electricity storage device 31...Power transmission device 32...Power transmission control unit 35...Power transmission power conversion unit, which is the power transmission unit 36...Power transmission antenna, which is the power transmission unit

Claims

1. A power transmission device configured to be movable, a power transmission unit that supplies power to a plurality of power receiving devices by wireless power supply; a power transmission control unit that controls the power transmission unit, The power transmission control unit Dividing the plurality of power receiving devices into groups based on the power supply capacity of the power transmitting device; moving the power transmitting device to a position where it can supply power to the group that is the power supply target; a power transmitting device that supplies power to the group that is the power supply target;

2. The power transmitting device according to claim 1 , wherein the power transmission control unit divides the plurality of power receiving devices into the groups based on a power supplyable by the power transmitting device and power consumption of each of the plurality of power receiving devices.

3. The power transmission control unit calculating a power supply time for each group based on the supplyable power of the power transmitting device, the power consumption of each of the plurality of power receiving devices, and the charging rates of the power storage devices included in the power receiving devices so that the charging rates of the power storage devices of the power receiving devices belonging to the group are equal to or greater than a predetermined threshold; The power transmitting device according to claim 1 , wherein power is supplied to the group that is the power supply target during the power supply time.

Images