Non-contact power supply system and non-contact power supply device

Abstract

A non-contact power supply system (10) is provided with: a power conversion means (120) for generating power to be transmitted to a power reception coil (211); a power transmission unit group (G1) comprising two or more power transmission units (110), each of the power transmission units having a power transmission circuit including a power transmission coil (111); a control unit (130) that controls the supply of power from the power conversion unit to the power transmission unit group; and a position detection unit (80) that detects the position of the moving body. On the basis of position information indicating the position of the moving body detected by the position detection unit, the control unit supplies power from the power conversion unit to the power transmission unit group satisfying the power transmission condition and does not supply power from the power conversion unit to the power transmission unit group not satisfying the power transmission condition. The power transmission condition includes that the relative distance of the power transmission coil with respect to the power reception coil of the moving body is equal to or less than a predetermined threshold value.

Description

Citation of related applications

[0001] This application claims priority based on Japanese patent application No. 2022-76577 filed on May 6, 2022, and the entire contents of the patent application are incorporated into this specification by reference. Technical Field

[0002] The present disclosure relates to a contactless power supply system and a contactless power supply device. Background Art

[0003] Patent document 1 describes a technology related to a contactless power supply device that supplies power from a power transmission coil to a power receiving coil installed on a moving body. In the technology described in patent document 1, when the power transmission coil is not opposite to the power receiving coil, the input impedance of the power transmission resonance circuit having the power transmission coil is set to be small, and when the power transmission coil is opposite to the power receiving coil, the input impedance of the power transmission resonance circuit is set to be large. As a result, when the power transmission coil is not opposite to the power receiving coil, power is not supplied from the power transmission coil to the power supply coil. Prior art literature Patent Literature

[0004] Patent Document 1: Japanese Patent Application Publication No. 2021-23094 Summary of the invention

[0005] In the technology described in Patent Document 1, when the power transmission coil is not facing the power receiving coil, although the power supply from the power transmission coil to the power receiving coil is suppressed, the current supply from the power transmission circuit to the power transmission coil is not completely stopped. In other words, in the technology described in Patent Document 1, even when the power transmission coil is not facing the power receiving coil, there is a standby current that always flows into each power transmission coil. Such a standby current increases as the number of power transmission coils increases.

[0006] The present disclosure can be implemented in the following forms.

[0007] According to one embodiment of the present disclosure, a contactless power supply system is provided. The contactless power supply system supplies power to a mobile body including a power receiving unit having a power receiving coil. The contactless power supply system includes: a power conversion unit that generates power for transmitting power to the power receiving coil; one or more power transmission unit groups, each of which is composed of two or more power transmission units, each of which has a power transmission circuit including a power transmission coil, and each of which receives power supply from the power conversion unit and transmits power from the power transmission coil to the power receiving coil; a control unit that controls the power supply from the power conversion unit to the power transmission unit group; and at least one position detection unit that detects the position of the mobile body. The control unit supplies power from the power conversion unit to the power transmission unit group that meets the power transmission condition based on the position information indicating the position of the mobile body detected by the position detection unit, and does not supply power from the power conversion unit to the power transmission unit group that does not meet the power transmission condition, wherein the power transmission condition includes that the relative distance of the power transmission coil relative to the power receiving coil of the mobile body is less than a predetermined threshold.

[0008] According to such a method, the supply or stop of power from the power conversion unit is controlled according to whether the power transmission conditions including the relative distance between the power transmission coil and the power receiving coil being below a predetermined threshold value are satisfied. Therefore, compared with the method of controlling the input impedance of the resonant circuit for power transmission, the standby current that always flows into the power transmission coil can be reduced.

[0009] According to another embodiment of the present disclosure, a contactless power supply device is provided. The contactless power supply device supplies power to a mobile body (200) including a power receiving unit (210) having a power receiving coil (211). The contactless power supply device includes: a power conversion unit (120) that generates power for transmitting power to the power receiving coil; one or more power transmission unit groups (G1), each of which is composed of two or more power transmission units (110), each of which has a power transmission circuit including a power transmission coil (111), and each of which receives power supply from the power conversion unit and transmits power from the power transmission coil to the power receiving coil; a control unit (130) that controls the power supply from the power conversion unit to the power transmission unit group; and at least one position detection unit (80) that detects the position of the mobile body. The control unit supplies power from the power conversion unit to the power transmission unit group that meets the power transmission condition based on the position information indicating the position of the moving body detected by the position detection unit, and does not supply power from the power conversion unit to the power transmission unit group that does not meet the power transmission condition, wherein the power transmission condition includes that the relative distance between the power transmission coil and the power receiving coil of the moving body is below a predetermined threshold.

[0010] According to such a method, the supply or stop of power from the power conversion unit is controlled according to whether the power transmission conditions including the relative distance between the power transmission coil and the power receiving coil being below a predetermined threshold value are satisfied. Therefore, compared with the method of controlling the input impedance of the resonant circuit for power transmission, the standby current that always flows into the power transmission coil can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS The above objects, other objects, features and advantages of the present disclosure will become more apparent with reference to the accompanying drawings and the following detailed description. Figure 1 It is a diagram showing a schematic configuration of a power supply system. Figure 2 This is a diagram showing an overview of the circuit configuration of a power supply device and a small mobile device. Figure 3 It is a diagram for explaining the relative state and the non-relative state of the coils. Figure 4 This is a diagram showing an overview of the circuit configuration of a power supply device and a small mobile device according to a second embodiment. Figure 5 This is a diagram showing a state where a plurality of power transmission unit groups are arranged. Figure 6 This is a diagram showing a small mobile device traveling in a factory where a robot is working. DETAILED DESCRIPTION

[0012] A1. Implementation Method 1 like Figure 1 As shown, the power supply system 10 wirelessly supplies power to a small mobile device 200 as a mobile body. The small mobile device 200 is, for example, a transport device for transporting parts in a factory. The power supply system 10 is also called a contactless power supply system. The power supply system 10 includes a power supply device 100, a transmission line 50, a line 60, a power source 70, and a sensor 80.

[0013] like Figure 2 As shown, the power supply device 100 includes a plurality of power transmission coil units 110, a plurality of power conversion units 120, and a control unit 130. The power supply device 100 is also referred to as a contactless power supply device.

[0014] The power transmission coil unit 110 supplies the power supplied from the power conversion unit 120 to the power receiving coil unit 210 included in the small mobile device 200. The power transmission coil unit 110 is also referred to as a power transmission unit. Figure 1As shown, in Embodiment 1, a plurality of power transmission coil units 110 of the power supply device 100 are buried or laid on the ground in a part of the moving range of the small mobile device 200. In the embodiment, it is assumed that the ground is a plane parallel to the horizontal plane, or a plane within +-10 degrees relative to the horizontal plane. Hereinafter, the plurality of power transmission coil units 110 are sometimes collectively referred to as a power transmission unit group G1. Figure 1 In the illustrated example, 20 power transmission coil units 110 arranged in 4 rows and 5 columns are defined as one power transmission unit group G1 , and two power transmission unit groups G1 are illustrated. Each power transmission unit group G1 is connected in parallel to the power conversion unit 120 via the transmission line 50 .

[0015] like Figure 2 As shown, the power transmission coil unit 110 includes a power transmission coil 111 and a capacitor 112 connected in series. The power transmission coil 111 and the capacitor 112 together constitute a power transmission resonance circuit. The power transmission resonance circuit is also called a power transmission circuit.

[0016] The power conversion unit 120 generates power for transmitting power to the power receiving coil unit 210. The power conversion unit 120 includes a power factor improvement circuit 121, an inverter circuit 122, and a filter 123. The power factor improvement circuit 121 rectifies and boosts the AC power supplied from the power source 70, converts it into DC power, and improves the power factor of the power supply device 100 as a load. The inverter circuit 122 converts the DC power generated by the power factor improvement circuit 121 into AC power of a desired frequency, and supplies the AC power to the power transmission coil unit 110. The inverter circuit 122 includes, for example, a full bridge circuit composed of four switching transistors. According to the control of the control unit 130, by turning on or off the four switching transistors included in the inverter circuit 122, the supply of AC power to the power transmission coil unit 110 is switched or stopped. The filter 123 passes only the AC power of a predetermined frequency band among the AC power input from the inverter circuit 122. The filter 123 includes a fourth-order filter composed of a coil 31 and a capacitor 32 , respectively.

[0017] The control unit 130 controls the inverter circuit 122 of the power conversion unit 120 to supply AC power of a desired frequency to the power transmission coil unit 110. In addition, the control unit 130 controls the inverter circuit 122 of the power conversion unit 120 to stop supplying AC power to the power transmission coil unit 110. The function of the control unit 130 is realized by, for example, a microcomputer including a processor, a memory, etc. The conditions under which the control unit 130 supplies power to the power transmission coil unit 110 by controlling the inverter circuit 122 will be described later.

[0018] Figure 1The transmission line 50 shown is a line connecting the power conversion unit 120 and the power transmission unit group G1. The line 60 is a line connecting the power source 70 and the power supply device 100. The power source 70 is an AC power source that supplies the power conversion unit 120 with AC power.

[0019] The sensor 80 is a position detector used by the control unit 130 to detect the position of the small mobile device 200. The sensor 80 is, for example, a camera disposed near the area where the power transmission coil unit 110 is installed. The sensor 80, for example, captures an image of the power transmission coil unit 110 at predetermined intervals and transmits the captured image data to the control unit 130 through communication. The sensor 80 is also referred to as a position detection unit.

[0020] The small mobile device 200 includes a power receiving coil unit 210, a power conversion unit 220, a battery 230, and a control unit 240. The small mobile device 200 travels using a motor driven by the power charged in the battery 230 as a power source.

[0021] The power receiving coil unit 210 receives power from the power transmitting coil unit 110. The power receiving coil unit 210 includes a power receiving coil 211 and a capacitor 212 connected in series. The power receiving coil unit 210 is also referred to as a power receiving unit. The power receiving coil 211 and the capacitor 212 together constitute a power receiving resonance circuit. Figure 1 As shown, when the small mobile device 200 stops on the power transmission coil unit 110 , the power reception coil 211 of the power reception coil unit 210 is arranged to face the power transmission coil 111 of the power transmission coil unit 110 .

[0022] like Figure 2 As shown, in a state where the power receiving coil 211 faces the power transmitting coil 111 of the power transmitting coil unit 110, an AC voltage is applied to the power transmitting coil 111, and when the AC current flows through the power transmitting coil 111, a magnetic flux is induced in the power transmitting coil 111. The induced magnetic flux interlinks with the power receiving coil 211, and the power receiving coil 211 receives power from the power transmitting coil 111. The power conversion unit 220 is connected to the power receiving coil unit 210.

[0023] The power conversion unit 220 rectifies the electromotive force induced in the power receiving coil 211 and generates DC power. The generated DC power is supplied to the battery 230. The battery 230 stores the DC power supplied from the power supply device 100. The control unit 240 controls each part of the small mobile device 200. For example, when receiving power supply, the control unit 240 performs power reception by controlling the power conversion unit 220.

[0024] The following describes the conditions under which the control unit 130 causes the power conversion unit 120 to supply power to the power transmission coil unit 110. This condition is also referred to as a power transmission condition. In Embodiment 1, the power transmission condition is that the relative distance between the power transmission coil 111 and the power receiving coil 211 is less than a predetermined threshold. The control unit 130 controls the inverter circuit 122 of the power conversion unit 120 to supply power to the power transmission unit group G1 including the power transmission coil 111 that satisfies the power transmission condition.

[0025] On the other hand, when the power transmission condition is not satisfied for any of the power transmission coils 111 included in the power transmission unit group G1 , the control unit 130 controls the inverter circuit 122 of the power conversion unit 120 so as not to supply power to the power transmission unit group G1 .

[0026] Here, if Figure 3 As shown, in the state where the power transmission coil 111 and the power receiving coil 211 are opposite to each other, that is, the "opposite state", there are "directly facing state" and "partially overlapping state". The coil surface is parallel to the X-axis and the Y-axis. The direction perpendicular to the coil surface is the Z-axis. In addition, the coil surface refers to the surface surrounded by the ring-shaped wiring and functions as a ring-shaped coil.

[0027] The "directly facing state" refers to a state in which the center of the coil surface of the power transmission coil 111 coincides with the center of the coil surface of the power receiving coil 211, and refers to a state in which one of the coil surfaces of the power transmission coil 111 and the power receiving coil 211 entirely overlaps with the other. The coil surface of the power transmission coil 111 is larger than the coil surface of the power receiving coil 211. The "partially overlapping state" is a state in which the coil surface of the power receiving coil 211 partially overlaps with the coil surface of the power transmission coil 111. In the "partially overlapping state", the area in which the coil surface of the power transmission coil 111 overlaps with the coil surface of the power receiving coil 211 is smaller than the area in which the coil surface of the power transmission coil 111 overlaps with the coil surface of the power receiving coil 211 in the directly facing state.

[0028] In addition, in the state where the power receiving coil 211 is not opposite to the power transmitting coil 111, that is, the "non-opposite state", there are a "boundary state", a "separated state" and an "isolated state". The "boundary state" is a state where the coil surface of the power receiving coil 211 does not overlap with the coil surface of the power transmitting coil 111, but the end edge of the coil surface of the power transmitting coil 111 overlaps with the end edge of the coil surface of the power receiving coil 211. As shown in the figure, the end edge of one side of the coil surface of the power transmitting coil 111 and the end edge of one side of the coil surface of the power receiving coil 211 are located at the same position in the X-axis direction. In the "boundary state", the area where the coil surface of the power transmitting coil 111 and the coil surface of the power receiving coil 211 are opposite is equal to zero.

[0029] The "separated state" is a state in which the coil surface of the receiving coil 211 does not overlap with the coil surface of the transmitting coil 111, and further, the end edge of the coil surface of the transmitting coil 111 does not overlap with the end edge of the coil surface of the receiving coil 211. As shown in the figure, the end edge of the coil surface of the transmitting coil 111 and the end edge of the coil surface of the receiving coil 211 are located at different positions in the X-axis direction. In the "separated state", the coil surface of the transmitting coil 111 is completely separated from the coil surface of the receiving coil 211. The "isolated state" is a state in which the transmitting coil 111 and the receiving coil 211 are in a relative state, but the transmitting coil 111 and the receiving coil 211 are isolated at a distance greater than the distance at which the transmitting coil 111 and the receiving coil 211 do not undergo electromagnetic coupling.

[0030] In the first embodiment, the power transmission coil 111 and the power receiving coil 211 are opposite to each other when the power transmission coil 111 and the power receiving coil 211 are in a "directly facing state" or when the power transmission coil 111 and the power receiving coil 211 are in a "partially overlapping state". When the power transmission coil 111 and the power receiving coil 211 are opposite to each other, the relative distance between the power transmission coil 111 and the power receiving coil 211 is a distance at which the power transmission coil 111 and the power receiving coil 211 can be electromagnetically coupled.

[0031] The small mobile device 200 may enter the range where any of the power transmission unit groups G1 are set, and the distance between the power receiving coil 211 of the small mobile device 200 and any of the power transmission coils 111 included in the power transmission unit group G1 becomes less than a predetermined threshold value. In this case, the power transmission condition is satisfied. In addition, the power receiving coil 211 and any of the power transmission coils 111 are not necessarily opposite. In the case where the movement speed of the small mobile device 200 is fast, after the small mobile device 200 enters the range where any of the power transmission unit groups G1 are set, when the power supply to the power transmission unit group G1 is started by the control of the control unit 130, the timing of starting the power supply to the small mobile device 200 may be delayed. In this case, it is desirable to start the power supply to the power transmission unit group G1 by the control of the control unit 130 before the small mobile device 200 enters the range where the power transmission unit group G1 is set. In this case, the distance between the power receiving coil 211 of the small mobile device 200 and any of the power transmission coils 111 becomes less than a predetermined threshold value before the small mobile device 200 enters the range where any of the power transmission unit groups G1 are set, and the power transmission condition is satisfied. The predetermined threshold value is determined in consideration of the operation of the power supply system 10 and the small mobile device 200 .

[0032] For example, the control unit 130 determines the position of the small mobile device 200 based on the received image data each time it receives image data from the sensor 80. Specifically, the control unit 130 determines whether the small mobile device 200 is within the range where any power transmission unit group G1 is set based on the image data received from the sensor 80. When the small mobile device 200 exists within the range where any power transmission unit group G1 is set, the control unit 130 determines the power transmission unit group G1 where the small mobile device 200 is located. When the small mobile device 200 is within the range where any power transmission unit group G1 is set, the control unit 130 controls the power conversion unit 120 corresponding to the power transmission unit group G1 and starts supplying power to the power transmission unit group G1.

[0033] If the relative distance between the power transmission coil 111 and the power reception coil 211 exceeds the threshold, the power transmission condition is not satisfied. The power transmission condition is not satisfied when, for example, the small mobile device 200 is not within the range where any power transmission unit group G1 is installed.

[0034] For example, after the control unit 130 starts supplying power to the power transmission unit group G1, when it is determined based on the image data received from the sensor 80 that there is no small mobile device 200 within the range where the power transmission unit group G1 is set, the control unit 130 controls the power conversion unit 120 corresponding to the power transmission unit group G1 and stops supplying power to the power transmission unit group G1.

[0035] In Embodiment 1, the control unit 130 determines whether the power transmission condition including that the relative distance of the power transmission coil 111 to the power receiving coil 211 is a predetermined threshold value is satisfied based on the information obtained from the sensor 80. The control unit 130 switches the supply or stop of power from the power conversion unit 120 to the power transmission unit group G1 based on the result of the determination. Therefore, compared with the method of controlling the input impedance of the power transmission resonance circuit as described in Patent Document 1, the standby current that always flows into the power transmission coil 111 can be reduced.

[0036] A2. Implementation Method 2 In the first embodiment, the supply of electric power from the power conversion unit 120 to the power transmission coil unit 110 or the stop of the supply of electric power is controlled for each power transmission unit group G1. Therefore, the power transmission unit group G1 supplied with electric power from the power conversion unit 120 includes: the power transmission coil unit 110 including the power transmission coil 111 facing the power reception coil 211; and the power transmission coil unit 110 including the power transmission coil 111 not facing the power reception coil 211.

[0037] In Embodiment 2, the following structure is included in addition to the structure described in Embodiment 1, so that whether or not power transmission is performed is controlled for each power transmission coil unit 110. In addition, the following description will focus on the differences from Embodiment 1. The structure not particularly mentioned in the following description is the same as that of Embodiment 1.

[0038] like Figure 4 As shown, the control unit 130 controls the input impedance of each power transmission resonance circuit so that the input impedance of the power transmission resonance circuit including the power transmission coil 111 not facing the power reception coil 211 is greater than the input impedance of the power transmission resonance circuit including the power transmission coil 111 facing the power reception coil 211. Input impedance is also called impedance.

[0039] Specifically, the control unit 130 sets the inductance L of the power transmission coil 111 in a power transmission resonance circuit including the power transmission coil 111 facing the power reception coil 211 so that the resonance frequency frt matches the fundamental frequency fsw of the AC power. g1 and the capacitance C of capacitor 112 g1 At least one of. When the resonance frequency frt is consistent with the basic frequency fsw of the AC power, the resonance condition of the power transmission resonance circuit is satisfied. Therefore, the power transmission resonance circuit including the power transmission coil 111 opposite to the power receiving coil 211 is in a resonance state. In addition, the basic frequency fsw of the AC power is the basic frequency of the AC power supplied from the power conversion unit 120 to the power transmission coil unit 110.

[0040] In addition, the control unit 130 sets the inductance L of the power transmission coil 111 in a power transmission resonance circuit including the power transmission coil 111 that is not opposite to the power reception coil 211 so that the resonance frequency frt does not coincide with the fundamental frequency fsw of the AC power. g1 and the capacitance C of capacitor 112 g1 When the resonance frequency frt is not consistent with the fundamental frequency fsw of the AC power, the resonance condition of the power transmission resonance circuit is not satisfied. In this case, the power transmission resonance circuit including the power transmission coil 111 not facing the power receiving coil 211 is in a non-resonant state. The inductance L of the power receiving coil 211 is v and the capacitance C of capacitor 212 v , it is set that the resonance condition of the power receiving resonance circuit is satisfied, and the resonance frequency frr is consistent with the fundamental frequency fsw of the AC power.

[0041] In the resonant state, the imaginary part of the input impedance of the power transmission resonance circuit takes a value close to 0. On the other hand, in the non-resonant state, the imaginary part of the input impedance of the power transmission resonance circuit does not take a value close to 0. In other words, the input impedance of the power transmission resonance circuit in the resonant state is smaller than the input impedance of the power transmission resonance circuit in the non-resonant state. Therefore, in the power transmission resonance circuit in the non-resonant state, the inflow of current can be suppressed compared with the power transmission resonance circuit in the resonant state.

[0042] Since the input impedance is set so as not to satisfy the resonance condition for the power transmission resonance circuit including the power transmission coil 111 which is not in an opposed state with respect to the power reception coil 211, it is possible to suppress the power transmission from the power transmission coil unit 110 to the power reception coil unit 210. On the other hand, since the input impedance is set so as to satisfy the resonance condition for the power transmission resonance circuit including the power transmission coil 111 which is in an opposed state with respect to the power reception coil 211, the power transmission from the power transmission coil unit 110 to the power reception coil unit 210 is not suppressed.

[0043] exist Figure 4 In the example shown, as the capacitor 112, a capacitor capable of changing the capacitance C g1 Therefore, the control unit 130 changes the capacitance C of the capacitor 112. g1 Alternatively, as the power transmission coil 111, a variable inductance L may be used. g1 In the relative state, the inductance L of the power transmission coil 111 is controlled by the control unit 130. g1 In the non-relative state, the inductance L of the power transmission coil 111 is set to a value that satisfies the resonance condition. g1 Set to a value that does not satisfy the resonance condition.

[0044] Alternatively, a configuration using a variable capacitor as the capacitor 112 and a configuration using a variable coil as the power transmission coil 111 may be used in combination. In the non-opposing state, the inductance L of the power transmission coil 111 can be reduced. g1 , and reduce the capacitance C of capacitor 112 g1 Therefore, the inductance L of the power transmission coil 111 is set g1 and the capacitance C of capacitor 112 g1 Compared with either case, the input impedance can be further increased.

[0045] Alternatively, a configuration may be adopted in which the power transmission resonance circuit includes a variable resistor, and the input impedance of the power transmission resonance circuit may be controlled by controlling the resistance value of the variable resistor.

[0046] In this way, in the second embodiment, it is possible to suppress power transmission from the non-opposing power transmission coil 111 among the plurality of power transmission coil units 110 included in the power transmission unit group G1 to which power is supplied from the power conversion unit 120 to the power receiving coil 211. On the other hand, power transmission from the opposing power transmission coil 111 to the power receiving coil 211 is not suppressed. In this way, it is possible to control the implementation of power transmission to the power receiving coil unit 210 for each power transmission coil unit 110. Since unnecessary power transmission is not performed for the power transmission coil unit 110 to which power transmission is required, power can be supplied efficiently.

[0047] A3. Implementation Method 3 Furthermore, the power conversion unit 120 can supply power not only to the power transmission coil unit 110 whose relative distance from the power transmission coil 111 to the power reception coil 211 is equal to or smaller than the threshold, but also to the adjacent power transmission coil unit 110 .

[0048] Specifically, the power transmission conditions may also include the following conditions: (i) The relative distance between the power transmission coil 111 and the power reception coil 211 included in the small mobile device 200 is less than a threshold value; or, (ii) Another power transmission unit group G1 adjacent to the power transmission unit group G1 satisfying that the relative distance between the power transmission coil 111 and the power reception coil 211 of the small mobile device 200 is equal to or smaller than the threshold value.

[0049] For the power transmission unit group G1 that meets the above (ii), it is assumed that the relative distance of the power transmission coil 111 with respect to the power receiving coil 211 of the small mobile device 200 is less than the threshold value and the relative distance of the power transmission coil 111 with respect to the power receiving coil 211 of the small mobile device 200 exceeds the threshold value. In Embodiment 3, it is sufficient that the power transmission unit group G1 that meets (ii) is adjacent to the power transmission unit group G1 that meets (i). For the power transmission unit group G1 that meets (ii), the relative distance of the power transmission coil 111 with respect to the power receiving coil 211 of the small mobile device 200 is not limited. For example, when at least a portion of the boundary of the area where the power transmission unit group G1 that meets (i) is set overlaps with at least a portion of the boundary of the area where the other power transmission unit group G1 is set, it can also be determined that the other power transmission unit group G1 is adjacent to the power transmission unit group G1 that meets (i).

[0050] Alternatively, when the distance in the horizontal plane between the boundary of the area where the power transmission unit group G1 that meets (i) is set and the boundary of the area where the other power transmission unit group G1 is set is less than a preset distance, it can be determined that the other power transmission unit group G1 is adjacent to the power transmission unit group G1 that meets (i). In this case, it is preferred that the distance between the boundary of the power transmission unit group G1 and the boundary of the other power transmission unit group G1 is a distance that the small mobile device 200 can cross. This is to ensure that the small mobile device 200 can continue to be powered.

[0051] For example, Figure 5 As shown in FIG. 1 , it is assumed that a plurality of power transmission unit groups G1 are provided in a path on which a small mobile device 200 travels. Figure 5 , the power source 70, the sensor 80, the control unit 130, etc. are omitted. A small mobile device 200 exists in an area where the power transmission unit group G112 among the plurality of power transmission unit groups G1 is provided. In this case, the control unit 130 determines the power transmission unit groups G111, G113, G121, and G122 arranged around the power transmission unit group G112 as power transmission unit groups adjacent to the power transmission unit group G112. The control unit 130 controls the power conversion unit 120 to supply power to the adjacent power transmission unit groups.

[0052] For example, when the small mobile device 200 moves from the current power transmission unit group G1, power is supplied from the power conversion unit 220 to other adjacent power transmission unit groups G1 before the small mobile device 200 enters. Therefore, even when the small mobile device 200 moves, power can be continuously supplied to the small mobile device 200. In addition, compared with the case where the current is flowed into the power transmission unit group G1 after the small mobile device 200 is detected to enter the power transmission unit group G1, the time before the current flows into the power transmission coil 221 can be shortened.

[0053] In addition, it is assumed that the direction in which the small mobile equipment 200 enters the plurality of power transmission unit groups G1 is constant. Figure 5In the example shown, it is assumed that the small mobile device 200 enters from the column in which the power transmission unit groups G111, G121, G131, and G141 are provided in a direction intersecting the column. In this case, the control unit 130 may also control the power conversion unit 120 to always supply power to the power transmission unit groups G111, G121, G131, and G141. Alternatively, the control unit 130 may also estimate the moving direction of the small mobile device 200 based on the orientation of the small mobile device 200 and the current position of the small mobile device 200, for example, based on the image data obtained by the camera as the sensor 80. In this case, it is assumed that the control unit 130 estimates the moving direction of the small mobile device 200. The control unit 130 may also supply power from the power conversion unit 220 to one or more power transmission unit groups G1 arranged in the estimated moving direction.

[0054] In addition, it is preferable that the phases of the output voltages of the power conversion units 120 that supply power to the power transmission unit groups G1 are synchronized. This is to continuously supply power to the small mobile device 200 while the small mobile device 200 moves across a plurality of power transmission unit groups G1.

[0055] A4. Implementation Method 4 In Embodiment 1, an example in which the sensor 80 is a camera is described. The sensor 80 is not limited to a camera. As the sensor 80, a weight sensor or a load switch set on the ground may also be used. When the weight sensor or the load switch is subjected to a load, it sends a detection signal to the control unit 130 through wireless communication. For example, a plurality of weight sensors or load switches may also be set at the boundary of the area where the power transmission unit group G1 is set. When the small mobile device 200 passes through the boundary of the area where the power transmission unit group G1 is set, the weight sensor or the load switch sends a detection signal indicating that the load is applied to the control unit 130. In addition, it is assumed that the control unit 130 stores information indicating the positions where the weight sensors or load switches are respectively configured in the memory in advance. The control unit 130 can determine which power transmission unit group G1 the small mobile device 200 has entered based on the configuration position of the weight sensor or the load switch as the transmission source of the detection signal.

[0056] Alternatively, a laser sensor may be used as the sensor 80. For example, one or more laser sensors may be located at a position capable of detecting an object passing through the boundary of an area where the power transmission unit group G1 is provided. When the small mobile device 200 passes through the boundary of an area where the power transmission unit group G1 is provided, the laser sensor sends a detection signal indicating the detection of the passing to the control unit 130. In addition, it is assumed that the control unit 130 stores information indicating the positions where the laser sensors are respectively configured in advance in a memory. The control unit 130 can determine which power transmission unit group G1 the small mobile device 200 has entered based on the detection signal received from the laser sensor.

[0057] In addition, for example, it is assumed that a gate that automatically opens and closes when the small mobile device 200 is detected is provided in the passage leading to the area where the power transmission unit group G1 is provided. In this case, when a detection signal indicating that the gate is opened is received from the gate, the control unit 130 can also determine that the small mobile device 200 has entered the area where the power transmission unit group G1 is provided.

[0058] A5. Implementation Method 5 In Embodiments 1 and 3, an example of using a position detector provided on the outside of the small mobile device 200 as the sensor 80 is described. Alternatively, a position detector included in the small mobile device 200 may be used as the sensor 80. For example, the small mobile device 200 may also include an antenna and a GPS (Global Positioning System) receiver. The small mobile device 200 may also send the position information received by the GPS receiver and the information identifying the machine to the control unit 130 at a predetermined time interval. The control unit 130 determines which power transmission unit group G1 the small mobile device 200 has entered based on the position information received from the small mobile device 200. The control unit 130 is capable of individually detecting the position of the small mobile device 200 by using position detectors respectively provided on the small mobile device 200. The position detector included in the small mobile device 200 is also referred to as a first position detector. A fixedly provided position detector is also referred to as a second position detector. In addition, as the sensor 80, a position detector provided on the outside of the small mobile device 200 and a position detector equipped on the small mobile device 200 may also be used in combination. Alternatively, instead of using a position detector provided outside the small mobile device 200 , only a position detector provided in the small mobile device 200 may be used as the sensor 80 .

[0059] A6. Implementation Method 6 The small mobile device 200 may also include a function of selecting not to receive power supply. For example, it is assumed that the power receiving condition for the small mobile device 200 to receive power supply is set to the power stored in the battery 230 being below the reference value. In this case, the control unit 240 of the small mobile device 200 determines that power supply is not required and selects not to receive power supply when the power stored in the battery 230 exceeds the reference value. The control unit 240 is also called a selection unit.

[0060] When the control unit 240 selects not to receive the supply of power, it controls the power conversion unit 220 so as not to generate DC power using the electromotive force induced in the power receiving coil 211. In this way, the small mobile device 200 selects whether to receive power in such a manner that it receives power when the power receiving condition is met and does not receive power when the power receiving condition is not met. Therefore, power can be supplied at an appropriate time corresponding to the status of the small mobile device 200.

[0061] In addition, or alternatively, a transmitter that outputs a prohibition signal indicating prohibition of power transmission may be included in the small mobile device 200. For example, the control unit 240 of the small mobile device 200 is capable of continuously outputting a prohibition signal from the transmitter during a period in which the power receiving condition is not satisfied. The transmitter is also referred to as a machine. The control unit 130 monitors whether there is a small mobile device 200 that outputs a prohibition signal in an area where the power transmission unit group G1 is provided. For example, a small mobile device 200 that outputs a prohibition signal sometimes enters the power transmission unit group G1 to which power is supplied. In this case, the control unit 130 controls the power conversion unit 120 to stop supplying power to the power transmission unit group G1. In addition, for example, a small mobile device 200 that outputs a prohibition signal and other small mobile devices 200 that do not output a prohibition signal sometimes enter the power transmission unit group G1 to which power is not supplied. In this case, the control unit 130 controls the power conversion unit 120 to not supply power to the power transmission unit group G1.

[0062] In addition, it is assumed that the small mobile device 200 is traveling for the purpose of maintaining the power transmission unit group G1. In this case, the small mobile device 200 can also continuously output the prohibition signal regardless of the power receiving condition. For example, even if the small mobile device 200 is located in the area where the power transmission unit group G1 is set, when the small mobile device 200 outputs the prohibition signal, the control unit 130 does not supply power from the corresponding power conversion unit 120 to the power transmission unit group G1. In this way, power can be supplied at an appropriate time corresponding to the state of the small mobile device 200.

[0063] In addition, the transmitter that outputs the prohibition signal may also be carried by a person. For example, an operator working on or near the power transmission unit group G1 may carry the transmitter. When the control unit 130 detects the output of the prohibition signal within a predetermined range from the power transmission unit group G1, the power conversion unit 120 corresponding to the power transmission unit group G1 is not supplied with power.

[0064] The transmitter that outputs the prohibition signal may also be included only in the small mobile device 200, and the person may not carry the transmitter. Alternatively, the person may only carry the transmitter that outputs the prohibition signal, and the transmitter may not be included in the small mobile device 200. In addition, or alternatively, the transmitter may be included in the small mobile device 200, and the person may also carry the transmitter.

[0065] A7. Implementation Method 7 In the first embodiment, the control unit 130 detects the position of the small mobile device 200 and supplies electric power to the power transmission unit group G1 arranged at the position.

[0066] like Figure 6 As shown, an example is described in which a small mobile device 200 travels in a factory where robots R11, R12, R13, R14, and R15 work in order to assemble parts. Figure 6 In the figure, the power supply 70, the control unit 130, etc. are omitted. The small mobile device 200 includes five small mobile devices 200a~200g. Hereinafter, the small mobile devices 200a~200d are sometimes collectively referred to as small mobile devices 200. In the factory, robots R11, R12, R13, R14, and R15 work to assemble parts. Robots R11, R12, R13, R14, and R15 are sometimes collectively referred to as robots R1. The small mobile device 200 receives the workpiece from the robot R1 and drives autonomously in the factory to transport the workpiece to other robots R1. The small mobile device 200 functions as a so-called unmanned guided vehicle (AGV).

[0067] exist Figure 6 In the example shown, the small mobile devices 200a to 200e perform the transporting operation. The small mobile devices 200f to 200g are on standby outside the driving route in case the small mobile devices 200a to 200e cannot perform the transporting operation due to maintenance or failure. It is assumed that the small mobile device 200 includes a processor and a memory. In the memory included in the small mobile device 200, a driving program for controlling the small mobile device 200 is stored to circle at a specified speed in a predetermined driving route. By executing the driving program through the processor included in the small mobile device 200, the autonomous operation function of the small mobile device 200 can be realized.

[0068] exist Figure 6 In the example shown, a magnetic tape M1 indicating the travel route of the small mobile device 200 is affixed to the ground in the factory. It is assumed that the small mobile device 200 includes a magnetic induction sensor. The small mobile device 200 travels along the travel route indicated by the magnetic tape M1. In addition, a magnetic mark indicating the position of the curve is provided at the curve of the travel route. The speed of the small mobile device 200 when traveling on a straight route and the speed of the small mobile device 200 when turning at a curve are predetermined. The speed when turning at a curve is set to be slower than the speed when traveling on a straight route. The small mobile device 200 determines whether it passes through a curve based on the magnetic mark indicating the position of the curve. Therefore, the small mobile device 200 decelerates when turning at a curve, and accelerates to the original speed after the turn at the curve is completed.

[0069] The small mobile devices 200a and 200b receive the workpiece WK1 from the robot R13 and carry the workpiece WK1 to the robot R15. The small mobile devices 200a and 200b are pre-set with information indicating the position of the curve to be turned. In addition, the small mobile devices 200a and 200b are set with information indicating which robot R1 should be stopped near. In this way, the small mobile devices 200a and 200b can travel on the same route.

[0070] The small mobile device 200c, 200d, 200e receives the workpiece WK2 from the robot R12 or R11, and carries the workpiece WK2 to the robot R14. The small mobile device 200c, 200d, 200e is pre-set with information indicating the position of the curve to be turned. In addition, the small mobile device 200c, 200d, 200e is set with information indicating which robot R1 should be stopped near. Therefore, the small mobile device 200c, 200d, 200e can travel on the same route.

[0071] In addition, it is assumed that a plurality of power transmission unit groups G1 are provided in a road on which the small mobile device 200 travels. The small mobile device 200 can receive power supply while traveling.

[0072] In Embodiment 7, the control unit 130 estimates the moving destination of the small mobile device 200. As described above, the driving speed on the straight route and the driving speed on the curve of the small mobile device 200 are preset. Therefore, the control unit 130 can estimate the current position of the small mobile device 200 based on the time when the small mobile device 200 starts to travel, the driving route of the small mobile device 200, and the set value of the driving speed. In this case, the control unit 130 may not receive the position information from the small mobile device 200. In addition, the control unit 130 can estimate the power transmission unit group G1 of the mobile destination entered by the small mobile device 200 based on the estimation result of the current position of the small mobile device 200. Before the small mobile device 200 enters the power transmission unit group G1 of the estimated mobile destination, the control unit 130 controls the corresponding power conversion unit 220 so that the current flows into the power transmission unit group G1 of the mobile destination.

[0073] Therefore, power can be continuously supplied to the small mobile device 200 traveling across a plurality of power transmission unit groups G1. In addition, the time until current flows into the power transmission coil 221 can be shortened compared to the case where current flows into the power transmission unit group G1 after the small mobile device 200 is detected to have entered the power transmission unit group G1.

[0074] In addition, if Figure 6 As shown, according to the assembly process, when the small mobile device 200 carries the workpieces WK1 and WK2 in the assembly plant, a travel plan including the route traveled by the small mobile device 200 and the number of workpieces carried by the small mobile device 200 is predetermined. Travel plan information representing the travel plan is pre-stored in the memory included in the control unit 130. The memory included in the control unit 130 is also referred to as a first storage unit. The control unit 130 can also pre-calculate the energy consumed by the small mobile device 200 based on the travel plan and the weight of a workpiece, and estimate the time when the small mobile device 200 needs to be charged and the power required for charging. When the small mobile device 200 reaches the time when charging is required, the control unit 130 can also control the corresponding power conversion unit 220 before the small mobile device 200 enters the power transmission unit group G1 of the estimated moving destination, so that the current flows into the power transmission unit group G1 set on the travel route.

[0075] In addition, it is assumed that the small mobile device 200 that has been carrying out the transport operation for a predetermined time is maintained. For example, it is assumed that the small mobile device 200 counts the elapsed time from the start of driving. The small mobile device 200 is controlled by the driving program so that it moves outside the driving route when the elapsed time reaches a predetermined time. The small mobile device 200 can also be powered at the moment when the small mobile device 200 leaves the driving route. In this case, the power transmission unit group G1 is powered by the power transmission unit group G1 set outside the driving route.

[0076] In this way, the planned supply of power to the small mobile device 200 after the small mobile device 200 has performed the transport operation for a prescribed time from the start time of driving is called a power supply plan. As power supply plan information representing the power supply plan, a time predetermined as the elapsed time from the start time of driving is stored in the memory included in the control unit 130. The memory included in the control unit 130 is also referred to as a second storage unit. Before the small mobile device 200 that deviates from the driving route enters, the control unit 130 controls the corresponding power conversion unit 220 so that the current flows into the power transmission unit group G1 set outside the driving route. In the case where the small mobile device 200 is supplied with power from the power transmission unit group G1 set outside the driving route, the power transmission unit group G1 may not be set on the driving route.

[0077] Alternatively, the control unit 130 may control the corresponding power conversion unit 220 to flow current into the power transmission unit group G1 provided in the path where the predetermined small mobile equipment 200 deviating from the driving route travels before moving outside the driving route.

[0078] In addition, when any small mobile equipment 200 moves outside the travel route, any one of the small mobile equipment 200f and 200g that is on standby may move into the travel route and perform the transport operation.

[0079] A8. Implementation Method 8 Alternatively, the control unit 130 may also acquire detection data detected by a velocity sensor or an acceleration sensor from the small mobile device 200 through communication. In this case, it is assumed that the small mobile device 200 includes a velocity sensor or an acceleration sensor. The detection data includes velocity information indicating velocity or acceleration information indicating acceleration. The control unit 130 can estimate the current position of the small mobile device 200 based on the time when the small mobile device 200 starts to travel, the travel route, speed or acceleration of the small mobile device 200. The control unit 130 can estimate the power transmission unit group G1 of the mobile destination entered by the small mobile device 200 based on the estimated result of the current position of the small mobile device 200. Before the small mobile device 200 enters the power transmission unit group G1 of the estimated mobile destination, the control unit 130 controls the corresponding power conversion unit 220 so that current flows into the power transmission unit group G1 of the mobile destination. In this way, the mobile destination of the small mobile device 200 can be estimated with high accuracy.

[0080] A9. Implementation Method 9 In Embodiment 7, an example is described in which the control unit 130 estimates the destination of the small mobile device 200 based on the travel plan or the power supply plan. Alternatively, the control unit 130 may determine whether the small mobile device 200 needs power supply in the following manner.

[0081] It is assumed that the small mobile device 200 includes a function of monitoring the state of charge (SOC) of the battery 230. The small mobile device 200 obtains the remaining amount of power charged to the battery 230 based on the voltage of the battery 230 and the temperature of the battery 230. For example, it is assumed that the small mobile device 200 is controlled by a driving program so that when the remaining amount of power charged to the battery 230 is less than a certain value, it moves outside the driving route.

[0082] In this case, the control unit 130 may also obtain charging information indicating the charging state of the battery 230 included in the small mobile device 200 from the small mobile device 200. The charging information indicating the charging state of the battery 230 is, for example, information indicating the ratio of the amount of electricity currently stored in the battery 230 to the total capacity that can be stored in the battery 230. The control unit 130 may also determine that the battery 230 of the small mobile device 200 needs to be powered when the capacity currently stored in the battery 230 indicated by the charging information is lower than a predetermined reference value. For example, before the small mobile device 200 that deviates from the driving route enters, the control unit 130 controls the corresponding power conversion unit 220 so that the current flows into the power transmission unit group G1 set outside the driving route. In this case, the control unit 130 can predict the moving destination of the small mobile device 200 without relying on the driving plan or the power supply plan.

[0083] In addition, the control unit 130 may also acquire, from the small mobile device 200 through communication, time information indicating the charging time at which the battery 230 of the small mobile device 200 was charged in the past and distance information indicating the distance traveled by the small mobile device 200 from the time to the present. The charging performed in the past means that the battery 230 has not been charged after the charging. The control unit 130 can determine whether the battery 230 of the small mobile device 200 needs to be charged based on the distance traveled by the small mobile device 200 from the charging time at which the battery 230 was charged in the past.

[0084] In addition, when the battery 230 is in a state that requires charging, for example, before the small mobile device 200 that deviates from the driving route enters, the control unit 130 controls the corresponding power conversion unit 220 so that the current flows into the power transmission unit group G1 set outside the driving route. Alternatively, the control unit 130 may also infer that the small mobile device 200 has moved to the power transmission unit group G1 that is closer to the current position. The control unit 130 infers the moving destination of the mobile body that needs to receive power, and based on the inferred result of the moving destination of the small mobile device 200, supplies power from the corresponding power conversion unit 220 to the determined power transmission unit group G1. In this way, by using the charging information when inferring the moving destination, the moving destination of the small mobile device 200 can be inferred with high accuracy.

[0085] In addition, the control unit 130 may not acquire the time information indicating the charging time when the battery 230 was charged in the near future from the small mobile device 200. For example, the control unit 130 may store the time when the small mobile device 200 was powered on, which is determined based on the image data captured by the camera of the sensor 80, in the memory as the charging time. The control unit 130 can determine whether the battery 230 of the small mobile device 200 needs to be charged based on the charging time stored in the memory and the distance information indicating the distance traveled by the small mobile device 200 from the charging time acquired from the small mobile device 200.

[0086] A10. Implementation Method 10 In addition, in the case where the small mobile device 200 does not circle on a determined route, a driving plan such as the following is sometimes predetermined. In this case, the control unit 130 may also estimate the moving destination of the small mobile device 200 based on the driving plan information indicating the driving plan of the small mobile device 200. It is assumed that the driving plan information is pre-stored in the memory included in the control unit 130. The driving plan, for example, indicates that the small mobile device 200 moves to a set location at a set time. The driving plan information is, for example, information that associates information indicating a moving location with the moving time. Therefore, the control unit 130 can efficiently estimate the moving destination of the small mobile device 200 based on the driving plan information.

[0087] In addition, in the case where the small mobile device 200 does not circle on the determined route, a power supply plan such as the following is sometimes predetermined. In this case, the control unit 130 may also estimate the moving destination of the small mobile device 200 based on the power supply plan information indicating the power supply plan of the small mobile device 200. It is assumed that the power supply plan information is pre-stored in the memory included in the control unit 130. The power supply plan, for example, indicates that the small mobile device 200 is scheduled to be powered at a set time. The power supply plan information includes information indicating the scheduled power supply time for the small mobile device 200. For example, it is assumed that there is a small mobile device 200 scheduled to be powered between the current time and the time when 5 minutes have passed. The control unit 130 may also estimate that the small mobile device 200 will move to the power transmission unit group G1 that is closer to the current position. Therefore, the control unit 130 can efficiently estimate the moving destination of the small mobile device 200 based on the power supply plan information.

[0088] In addition, when a plurality of small mobile devices 200 are traveling in a factory, the small mobile device 200 may communicate with other small mobile devices 200, and may have a function of traveling in a manner that does not interfere with each other's traveling in order to avoid collision. In this case, the control unit 130 may also estimate the movement destination of the small mobile device 200 on the premise that other small mobile devices 200 do not enter a certain range including the current position of a certain small mobile device 200 within a predetermined period. Therefore, the movement destination of the small mobile device 200 can be effectively estimated.

[0089] A11. Implementation Method 11 In addition, the control unit 130 may also determine the position of the small mobile device 200 in the following manner. The control unit 130 may also determine whether the small mobile device 200 exists in the area where the power transmission unit group G1 is set based on the change in the amount of current from the power conversion unit 120 to the power transmission unit group G1. For example, a current sensor that detects the amount of current flowing out of the power conversion unit 120 is set between the power conversion unit 120 and the power transmission unit group G1. In addition, regardless of whether the small mobile device 200 exists on the power transmission unit group G1, a certain amount of current flows from the power conversion unit 120 to the power transmission unit group G1. In addition, in the following description, it is assumed that the control of the input impedance of the power transmission resonance circuit of the power transmission coil unit 110 described in Implementation Example 2 is not performed.

[0090] For example, when the small mobile device 200 enters the power transmission unit group G1, any power transmission coil 111 included in the power transmission unit group G1 faces the power receiving coil 211 of the small mobile device 200, and the power transmission resonance circuit including the power transmission coil 111 and the power receiving resonance circuit including the power receiving coil 211 enter a resonance state. In this case, since the input impedance of the power transmission resonance circuit becomes low, the current flowing from the power conversion unit 120 to the power transmission unit group G1 increases. The control unit 130 may also determine that the small mobile device 200 exists in the area where the power transmission unit group G1 is set when the amount of current flowing from the power conversion unit 120 to the power transmission unit group G1 increases to a predetermined reference value or more. In this way, the position of the small mobile device 200 can be detected with a simple structure without using information related to charging obtained from the sensor 80 and the small mobile device 200.

[0091] In addition, or alternatively, a current sensor for detecting the amount of current flowing into the power transmission coil 111 or a voltage sensor for detecting the voltage applied to the power transmission coil 111 may be provided in the power transmission coil 111. As described above, when the power transmission coil 111 faces the power receiving coil 211, and the power transmission resonance circuit including the power transmission coil 111 and the power receiving resonance circuit including the power receiving coil 211 are in a resonant state, the current flowing from the power conversion unit 120 to the power transmission unit group G1 increases. The control unit 130 can determine whether the small mobile device 200 is present in the area where the power transmission unit group G1 is provided, based on the detection value of the current sensor or the voltage sensor. In addition, the control unit 130 can identify the power transmission coil 111 facing the power receiving coil 211 of the small mobile device 200.

[0092] A12. Implementation Method 12 For example, it is assumed that power supply systems 10A and 10B are installed in a factory. The power supply systems 10A and 10B have Figure 1The power supply system 10 shown in the figure has the same structure. In this case, the control unit 130 of the power supply system 10A may also send information indicating whether a small mobile device 200 exists in the area where the power transmission unit group G1 as the control object is set to the control unit 130 included in the power supply system 10B. The power transmission unit group G1 as the control object of the control unit 130 of the power supply system 10A is the power transmission unit group G1 included in the power supply system 10A. In addition, the control unit 130 of the power supply system 10A may also receive information indicating whether a small mobile device 200 exists in the area where the power transmission unit group G1 included in the power supply system 10B is set from the control unit 130 of the power supply system 10B.

[0093] For example, it is assumed that there are fewer small mobile devices 200 in the power transmission unit group G1 included in the power supply system 10A, and there are more small mobile devices 200 in the power transmission unit group G1 included in other power supply systems 10. In this case, the control unit 130 of the power supply system 10B can notify through communication so that the small mobile device 200 in the area where the power transmission unit group G1 is set moves to the power supply system 10A. Therefore, it is possible to avoid the operating rate of the power supply system 10B exceeding the power supply capacity of the power supply system 10B. Through the cooperation of multiple control units 130, it is possible to efficiently supply power to the small mobile device 200.

[0094] A13. Implementation Method 13 The control unit 130 may also monitor the power supplied to the plurality of power transmission unit groups G1 during a predetermined period. For example, the control unit 130 may control the power conversion unit 120 that supplies power to a portion of the power transmission unit groups G1 so as to limit the power supply to a portion of the power transmission unit groups G1 when the total power supplied to the plurality of power transmission unit groups G1 per unit time exceeds a preset reference value.

[0095] For example, when the amount of power supplied to the power transmission unit group exceeds the amount of power that can be supplied from the power source 70 , power supply to a part of the power transmission unit group G1 is stopped, thereby preventing a power failure in the power supply system 10 from occurring.

[0096] In addition, the control unit 130 may also limit the power supply to the power transmission unit group G1 that is arranged at a position far from the small mobile device 200. The power transmission unit group G1 that is arranged at a position far from the small mobile device 200 refers to, for example, a power transmission unit group G1 that is at a distance greater than a predetermined distance from the small mobile device 200. This can avoid a situation where the small mobile device 200 cannot be continuously supplied with power.

[0097] The control unit 130 monitors the power supplied to the plurality of power transmission unit groups G1 during a predetermined period even after the power supply limitation is started. The control unit 130 continues limiting the power supply to a portion of the power transmission unit groups G1 until the total power in the determined period becomes less than a preset reference value. In addition, the control unit 130 may continue to increase the number of power transmission unit groups G1 that are the objects of power supply limitation until the total power in the determined period becomes less than a preset reference value.

[0098] The control unit 130 releases the control of supplying power to a part of the power transmission unit groups G1 when the total power in the determined period becomes less than a preset reference value. In addition, the control unit 130 may stop increasing the number of power transmission unit groups G1 that are the objects of power supply restriction when the total power in the determined period becomes less than the reference value. In addition, the control unit 130 may gradually reduce the number of power transmission unit groups G1 that are the objects of restriction according to the total power in the determined period.

[0099] B. Other Implementation Methods In Embodiment 1, an example is described in which one power conversion unit 120 controls the power supply to one power transmission unit group G1. However, one power conversion unit 120 may control the power supply to two or more power transmission unit groups G1.

[0100] In Embodiment 1, an example is described in which the power supply device 100 includes a plurality of power conversion units 120 , but the power supply device 100 may include a single power conversion unit 120 .

[0101] In Embodiment 1, the control unit 130 determines the power transmission unit group G1 where the small mobile device 200 is located based on the image data received from the sensor 80 . However, the control unit 130 may also determine the position of the small mobile device 200 within the power transmission unit group G1 based on the image data received from the sensor 80 .

[0102] In the first embodiment, an example is described in which the coil surface of the power transmission coil 111 is larger than the coil surface of the power reception coil 211 . However, the coil surface of the power transmission coil 111 may be the same size as or smaller than the coil surface of the power reception coil 211 .

[0103] exist Figure 1 In the illustrated example, the plurality of power transmission coil units 110 included in the power transmission unit group G1 are arranged in a matrix, but the power transmission coil units 110 may be arranged in a straight line.

[0104] The present disclosure is not limited to the above-mentioned embodiments, and can be implemented by various structures within the scope of the above-mentioned subject matter. For example, the technical features in the embodiments corresponding to the technical features in each method described in the invention content section can be appropriately replaced or combined to solve part or all of the above-mentioned technical problems, or to achieve part or all of the above-mentioned effects. In addition, the above-mentioned technical features can be appropriately deleted as long as they are not described as necessary structures in this specification.

[0105] The features of the present disclosure are as follows. [Method 1] A contactless power supply system (10) supplies power to a moving object (200) including a power receiving unit (210) having a power receiving coil (211), wherein the contactless power supply system comprises: a power conversion unit (120) for generating electric power for transmitting electric power to the power receiving coil; and One or more power transmission unit groups (G1), each of the power transmission unit groups being composed of two or more power transmission units (110), each of the power transmission units having a power transmission circuit including a power transmission coil (111), and each of the power transmission units receiving power from the power conversion unit and transmitting power from the power transmission coil to the power receiving coil; a control unit (130) for controlling the supply of electric power from the power conversion unit to the power transmission unit group; and at least one position detection unit (80), the position detection unit detecting the position of the moving body, The control unit is based on the position information indicating the position of the moving body detected by the position detection unit. supplying electric power from the power conversion unit to the power transmission unit group satisfying a power transmission condition, the power transmission condition including that a relative distance between the power transmission coil and the power receiving coil of the moving object is less than a predetermined threshold value, The power conversion unit does not supply power to the power transmission unit group that does not satisfy the power transmission condition. [Method 2] In the contactless power supply system described in embodiment 1, The control unit supplies electric power to the power receiving unit by controlling the power transmission circuit including the power transmission coil facing the power receiving coil so that the impedance of the power transmission circuit is smaller than the impedance of the power transmission circuit including the power transmission coil not facing the power receiving coil. The power supply to the power receiving unit is stopped by controlling the power transmission circuit including the power transmission coil not facing the power receiving coil to have a higher impedance than the power transmission circuit including the power transmission coil facing the power receiving coil. [Method 3] In the contactless power supply system described in aspect 1 or aspect 2, The position detection unit includes a first position detector, which is provided on the moving body and detects the position of the moving body. The control unit acquires, from the first position detector, information indicating the position of the moving body detected by the first position detector as the position information. [Method 4] In the contactless power supply system described in any one of aspects 1 to 3, The position detection unit includes a second position detector, which is disposed outside the moving body and detects the position of the moving body. The control unit acquires, from the second position detector, information indicating the position of the moving body detected by the second position detector as the position information. [Method 5] In the contactless power supply system described in any one of aspects 1 to 4, The position detection unit includes a second position detector, which is disposed outside the moving body and detects the position of the moving body. The control unit acquires, from the second position detector, information indicating the position of the moving body detected by the second position detector as the position information. [Method 6] In the contactless power supply system described in any one of aspects 1 to 5, The one or more power transmission unit groups are a plurality of the power transmission unit groups provided on the passageway on which the mobile body travels. The power conversion unit is configured to supply or stop power for each of the power transmission unit groups. The control unit estimates a destination of the moving body, determines the power transmission unit group set at the destination, and controls the power conversion unit to flow current into the determined power transmission unit group before the moving body enters an area where the determined power transmission unit group is set. [Method 7] In the contactless power supply system described in embodiment 6, The control unit acquires speed information or acceleration information indicating a speed or acceleration of the moving object from the moving object, and estimates the moving destination based on the speed or acceleration indicated by the speed information or the acceleration information. [Method 8] In the contactless power supply system described in aspect 6 or aspect 7, The system further includes a first storage unit, wherein the first storage unit stores predetermined travel plan information of the mobile body. The control unit estimates the destination based on the travel plan information. [Method 9] In the contactless power supply system described in any one of aspects 6 to 8, The system further includes a second storage unit, wherein the second storage unit stores predetermined power supply plan information of the mobile body. The control unit estimates the movement destination of the moving object based on the power supply plan information. [Method 10] In the contactless power supply system described in any one of aspects 6 to 9, A plurality of the above-mentioned moving bodies are traveling in the above-mentioned passage on which the above-mentioned moving body is traveling. The control unit estimates the destination of the moving body on the premise that the other moving bodies do not enter a range determined including a current position of one moving body within a predetermined period of time. [Method 11] In the contactless power supply system described in any one of aspects 1 to 10, The control unit determines whether the battery of the moving object needs to be charged based on information on a charging time at which the battery included in the moving object was recently charged and a distance traveled by the moving object from the charging time. [Method 12] In the contactless power supply system described in any one of aspects 1 to 11, The control unit acquires charging information indicating a charging state of a battery included in the moving object from the moving object, and determines whether the battery of the moving object needs to be charged based on the charging information. [Method 13] In the contactless power supply system described in any one of aspects 1 to 12, The mobile body further includes a selection unit configured to select whether to receive power from the power receiving unit. The selection unit prevents the power receiving unit from receiving electric power when the state of the moving object does not satisfy a preset power receiving condition. [Method 14] In the contactless power supply system described in any one of aspects 1 to 13, The above-mentioned power transmission conditions include: (i) the relative distance between the power transmission coil and the power reception coil of the moving object is equal to or smaller than the threshold value; or (ii) other power transmission unit groups adjacent to the power transmission unit group satisfying that the relative distance between the power transmission coil and the power reception coil of the moving object is equal to or smaller than the threshold value. [Method 15] In the contactless power supply system described in any one of aspects 1 to 14, The control unit determines the position of the moving object based on a change in an amount of current flowing from the power conversion unit to the power transmission unit group. [Method 16] In the contactless power supply system described in embodiment 15, The power transmission coil is provided with a current sensor for detecting the amount of current flowing into the power transmission coil or a voltage sensor for detecting the voltage applied to the power transmission coil. The control unit determines the position of the moving body based on a detection value of the current sensor or the voltage sensor. [Method 17] In the contactless power supply system described in any one of aspects 1 to 16, The control unit transmits information indicating whether the moving object exists in an area where the power transmission unit group to be controlled is installed to the control unit included in the other contactless power supply system. [Method 18] In the contactless power supply system described in any one of aspects 1 to 17, The control unit prevents the power conversion unit from supplying power to the power transmission unit group when the control unit detects the presence of a device outputting a prohibition signal indicating prohibition of power transmission within a predetermined range from the power transmission unit group. [Method 19] In the contactless power supply system described in any one of aspects 1 to 18, The one or more power transmission unit groups are a plurality of the power transmission unit groups. The control unit monitors the power supplied from the power conversion unit to the plurality of power transmission unit groups within a specified period, and controls the power conversion unit to limit the power supply to a portion of the plurality of power transmission unit groups when the total power within the specified period exceeds a preset reference value. [Method 20] In the contactless power supply system described in embodiment 19, The part of the power transmission unit groups to which power supply is restricted is the power transmission unit group whose distance from the moving object is greater than or equal to a predetermined distance. [Method 21] In the contactless power supply system described in aspect 19 or aspect 20, The control unit controls the power conversion unit so as to stop supplying power to the power transmission unit group until the total of the power becomes equal to or less than the reference value. [Method 22] In the contactless power supply system described in any one of aspects 19 to 21, the control unit continuously increases the number of the power transmission unit groups to be subject to power supply restriction until the total power becomes equal to or less than the reference value, When the total of the electric powers becomes equal to or less than the reference value, the increase in the number of the electric power transmission unit groups to which the electric power supply is restricted is stopped. [Method 23] A contactless power supply device (10) supplies power to a moving object (200) including a power receiving unit (210) having a power receiving coil (211), wherein the contactless power supply device comprises: a power conversion unit (120) for generating electric power for transmitting electric power to the power receiving coil; and One or more power transmission unit groups (G1), each of which is composed of two or more power transmission units (110), each of which has a power transmission circuit including a power transmission coil (111), and each of which receives power from the power conversion unit and transmits power from the power transmission coil to the power receiving coil; a control unit (130) for controlling the supply of electric power from the power conversion unit to the power transmission unit group; and at least one position detection unit (80), the position detection unit detecting the position of the moving body, The control unit is based on the position information indicating the position of the moving body detected by the position detection unit. supplying electric power from the power conversion unit to the power transmission unit group satisfying a power transmission condition, the power transmission condition including that a relative distance between the power transmission coil and the power receiving coil of the moving object is less than a predetermined threshold value, The power conversion unit does not supply power to the power transmission unit group that does not satisfy the power transmission condition.

Claims

1. A contactless power supply system (10) for supplying power to a moving object (200) including a power receiving unit (210) having a power receiving coil (211), the contactless power supply system comprising: a power conversion unit (120) for generating electric power for transmitting electric power to the power receiving coil; as well as A power transmission unit group (G1), the power transmission unit group being one or more power transmission unit groups, each of the power transmission unit groups being composed of two or more power transmission units (110), each of the power transmission units having a power transmission circuit including a power transmission coil (111), and each of the power transmission units receiving power supply from the power conversion unit and transmitting power from the power transmission coil to the power receiving coil; a control unit (130) for controlling the supply of electric power from the power conversion unit to the power transmission unit group; as well as at least one position detection unit (80) for detecting the position of the moving body, the control unit supplies power from the power conversion unit to the power transmission unit group that satisfies a power transmission condition based on position information indicating the position of the moving body detected by the position detection unit, the power transmission condition including that a relative distance between the power transmission coil and the power receiving coil of the moving body is less than a predetermined threshold value, The power conversion unit does not supply power to the power transmission unit group that does not satisfy the power transmission condition.

2. The contactless power supply system according to claim 1, characterized in that: The control unit supplies electric power to the power receiving unit by controlling the power transmission circuit including the power transmission coil facing the power receiving coil so that the impedance of the power transmission circuit is smaller than the impedance of the power transmission circuit including the power transmission coil not facing the power receiving coil. The power supply to the power reception unit is stopped by controlling the power transmission circuit including the power transmission coil not facing the power reception coil to have a higher impedance than the power transmission circuit including the power transmission coil facing the power reception coil.

3. The contactless power supply system according to claim 1 or 2, characterized in that: The position detection unit includes a first position detector provided on the moving body and detecting the position of the moving body. The control unit acquires, from the first position detector, information indicating the position of the moving body detected by the first position detector as the position information.

4. The contactless power supply system according to claim 3, characterized in that: The position detection section includes a second position detector which is provided outside the moving body and detects the position of the moving body. The control unit acquires, from the second position detector, information indicating the position of the moving body detected by the second position detector as the position information.

5. The contactless power supply system according to claim 1 or 2, characterized in that: The position detection section includes a second position detector which is provided outside the moving body and detects the position of the moving body. The control unit acquires, from the second position detector, information indicating the position of the moving body detected by the second position detector as the position information.

6. The contactless power supply system according to claim 1 or 2, characterized in that: The one or more power transmission unit groups are a plurality of power transmission unit groups provided on a passage on which the mobile body travels, The power conversion unit is configured to supply or stop power for each of the power transmission unit groups. The control unit estimates a destination of the moving body, determines the power transmission unit group set at the destination, and controls the power conversion unit to flow current into the determined power transmission unit group before the moving body enters an area where the determined power transmission unit group is set.

7. The contactless power supply system according to claim 6, characterized in that: The control unit acquires speed information or acceleration information indicating a speed or acceleration of the moving object from the moving object, and estimates the moving destination based on the speed or acceleration indicated by the speed information or the acceleration information.

8. The contactless power supply system according to claim 6, characterized in that: The system further includes a first storage unit storing predetermined travel plan information of the mobile body. The control unit estimates the destination based on the travel plan information.

9. The contactless power supply system according to claim 6, characterized in that: The system further includes a second storage unit storing predetermined power supply plan information of the mobile body. The control unit estimates the movement destination of the moving object based on the power supply plan information.

10. The contactless power supply system according to claim 6, characterized in that: A plurality of the moving bodies are traveling in the passage on which the moving body is traveling, The control unit estimates the movement destination of the moving body on the premise that the other moving bodies do not enter a certain range including a current position of one moving body within a predetermined period.

11. The contactless power supply system according to claim 1 or 2, characterized in that: The control unit determines whether the battery of the moving object needs to be charged based on information on a charging time at which a battery included in the moving object was recently charged and a distance traveled by the moving object from the charging time.

12. The contactless power supply system according to claim 1 or 2, characterized in that: The control section acquires charging information indicating a charging state of a battery included in the mobile body from the mobile body, and determines whether the battery of the mobile body needs to be charged based on the charging information.

13. The contactless power supply system according to claim 1 or 2, characterized in that: The mobile body further includes a selection unit configured to select whether the power receiving unit receives power. The selection unit prevents the power receiving unit from receiving electric power when the state of the moving object does not satisfy a preset power receiving condition.

14. The contactless power supply system according to claim 1 or 2, characterized in that: The power transmission conditions include: (i) the relative distance between the power transmission coil and the power reception coil of the moving object is equal to or smaller than the threshold value; or (ii) other power transmission unit groups adjacent to the power transmission unit group satisfying that the relative distance between the power transmission coil and the power reception coil of the moving object is equal to or smaller than the threshold value.

15. The contactless power supply system according to claim 1 or 2, characterized in that: The control unit determines the position of the moving object based on a change in the amount of current flowing from the power conversion unit to the power transmission unit group.

16. The contactless power supply system according to claim 1 or 2, characterized in that: The power transmission coil is provided with a current sensor for detecting the amount of current flowing into the power transmission coil or a voltage sensor for detecting the voltage applied to the power transmission coil. The control unit determines the position of the moving object based on a detection value of the current sensor or the voltage sensor.

17. The contactless power supply system according to claim 1 or 2, characterized in that: The control unit transmits information indicating whether the moving object exists in an area where the power transmission unit group to be controlled is installed to the control unit included in the other contactless power supply system.

18. The contactless power supply system according to claim 1 or 2, characterized in that: The control unit does not supply electric power from the power conversion unit to the power transmission unit group when the control unit detects the presence of a device outputting a prohibition signal indicating prohibition of power transmission within a predetermined range from the power transmission unit group.

19. The contactless power supply system according to claim 1, wherein: The one or more power transmission unit groups are a plurality of the power transmission unit groups, The control unit monitors the power supplied from the power conversion unit to the plurality of power transmission unit groups during a predetermined period, and controls the power conversion unit to limit the power supply to a portion of the plurality of power transmission unit groups when the total power during the predetermined period exceeds a preset reference value.

20. The contactless power supply system according to claim 19, wherein: The part of the power transmission unit groups to which power supply is restricted is the power transmission unit group whose distance from the moving object is greater than or equal to a predetermined distance.

21. The contactless power supply system according to claim 19 or 20, characterized in that: The control unit controls the power conversion unit to stop supplying power to the power transmission unit group until the total power becomes equal to or less than the reference value.

22. The contactless power supply system according to claim 21, characterized in that: The control unit continuously increases the number of the power transmission unit groups to be subject to power supply restriction until the total power becomes equal to or less than the reference value, When the total amount of the electric power becomes equal to or less than the reference value, the increase in the number of the electric power transmission unit groups to be subject to the restriction of electric power supply is stopped.

23. A contactless power supply device (10) for supplying power to a moving object (200) including a power receiving unit (210) having a power receiving coil (211), wherein: The contactless power supply device comprises: a power conversion unit (120) for generating electric power for transmitting electric power to the power receiving coil; and a power transmission unit group (G1), the power transmission unit group being one or more power transmission unit groups, each of the power transmission unit groups being composed of two or more power transmission units (110), each of the power transmission units having a power transmission circuit including a power transmission coil (111), and each of the power transmission units receiving power supply from the power conversion unit and transmitting power from the power transmission coil to the power receiving coil; a control unit (130) for controlling the supply of electric power from the power conversion unit to the power transmission unit group; and at least one position detection unit (80) for detecting the position of the moving body, The control unit determines, based on position information indicating the position of the moving object detected by the position detection unit, supplying electric power from the power conversion unit to the power transmission unit group satisfying a power transmission condition, the power transmission condition including that a relative distance between the power transmission coil and the power receiving coil of the moving object is less than a predetermined threshold value, The power conversion unit does not supply power to the power transmission unit group that does not satisfy the power transmission condition.

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