Non-contact power supply device

Abstract

To provide a non-contact power feeder whose operation load for installation work is reduced.SOLUTION: A non-contact power feeder 10 for feeding power to a power-receiving device in a non-contact manner comprises a power supply device 20 for outputting AC power; a power-transmitting coil L1 electrically connected to the power supply device; and a setting circuit 42 for setting the power-transmitting coil to one of a power-feeding state and a standby state, that intervenes between the power supply device and the power-transmitting coil. The setting circuit is formed separately from the power supply device.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] Conventionally, there is a power supply system that includes a power transmission coil supplied with power from a high frequency power source and that supplies power contactlessly to a power receiving coil mounted on a moving object, for example (see, for example, Patent Document 1). In the power supply system described in Patent Document 1, a current control element is disposed between the high frequency power source and the power transmission coil, and the impedance of which increases when the current flowing through the power transmission coil is below a threshold value, in order to suppress the current flowing through the power transmission coil in a standby state. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-71719 A Summary of the Invention [Problem to be solved by the invention]

[0004] The layout of the circuit for suppressing the current flowing through the power transmission coil in standby mode has not been sufficiently considered, and there is room for improvement. [Means for solving the problem]

[0005] The present disclosure can be realized in the following forms.

[0006] According to one embodiment of the present disclosure, there is provided a contactless power supply device (10, 210-710) that contactlessly supplies power to a power receiving device (92). The contactless power supply device includes a power supply device (20, 420, 620) that outputs AC power, a power transmission coil (L1) that is electrically connected to the power supply device, and a setting circuit (42, 242, 442, 542) that is interposed between the power supply device and the power transmission coil and that sets the power transmission coil to one of a power supply state and a standby state. a power transmission coil module (40, 240, 340, 640, 740) having one or more of the power transmission coils, the power supply device having a power supply housing,the setting circuit is separate from the power supply device, The power transmitting coil module includes a coil housing that is separate from the power supply housing, external connection terminals (MTP, MTN) for electrically connecting to the power supply device, the external connection terminals being exposed from the coil housing, wiring that electrically connects the external connection terminal and the power transmitting coil, and the setting circuit disposed on the wiring, the wiring and the setting circuit being housed in the coil housing, and the setting circuit being The power supplying state is set by setting the capacitance value of the variable capacitor to a first capacitance value, and the standby state is set by setting the capacitance value to a second capacitance value different from the first capacitance value. A third circuit has a plurality of capacitors (C5, C6) having different capacitance values ​​from each other, and a third circuit switch (SW1) that switches some of the plurality of capacitors to either a conducting state or a non-conducting state, and the power supplying state is set by setting the third circuit switch to either a conducting state or a non-conducting state, and the standby state is set by setting the third circuit switch to the other of the conducting state and the non-conducting state.

[0007] In this type of contactless power supply system, since the setting circuit is separate from the power supply device, when a new power transmission coil is added by connecting it in parallel with the power supply device, a wiring for supplying power to the new power transmission coil can be branched from any position between the power supply device and the setting circuit in the wiring connecting the power supply device and the power transmission coil. This reduces the workload of the installation work of the contactless power supply device 10. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of a contactless power supply system. [Diagram 2] FIG. 1 is a diagram showing a circuit configuration of a contactless power supply system. [Diagram 3] 4A and 4B are diagrams for explaining an opposing state and a non-opposing state of a power transmitting coil and a power receiving coil; [Figure 4] FIG. 11 is a diagram showing a circuit configuration of a non-contact power supply device according to a second embodiment. [Diagram 5] FIG. 11 is a plan view of a substrate on which a power transmitting coil and a capacitor are arranged according to a second embodiment. [Figure 6] FIG. 11 is a diagram illustrating an arrangement of a circuit configuration of a contactless power supply device according to a third embodiment. [Figure 7] FIG. 13 is a diagram showing a circuit configuration of a non-contact power supply device according to a fourth embodiment. [Figure 8] FIG. 13 is a diagram showing a circuit configuration of a contactless power supply device according to a fifth embodiment. [Figure 9] FIG. 13 is a diagram showing a circuit configuration of a contactless power supply device according to a sixth embodiment. [Figure 10] FIG. 13 is a diagram illustrating an arrangement of a circuit configuration of a contactless power supply device according to a seventh embodiment. [Figure 11] FIG. 13 is a diagram showing a circuit configuration of a power transmission circuit according to a first embodiment of the present invention. [Figure 12] FIG. 13 is a diagram showing a circuit configuration of a power transmission circuit according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A. First embodiment: 1, the contactless power supply system 1 includes a contactless power supply device 10 and a power receiving device 92 mounted on a vehicle 90. The contactless power supply device 10 supplies power to the power receiving device 92 in a contactless manner. The vehicle 90 is, for example, a vehicle equipped with a drive motor such as an electric vehicle or a hybrid vehicle. The power transmission coil module 40 included in the contactless power supply device 10 is installed on a road RS serving as a passageway along which the vehicle 90 travels.

[0010] As described below, the non-contact power supply device 10 includes a power transmission coil module 40 having a power transmission coil L1, and a power supply device 20 for supplying power to the power transmission coil L1. In this configuration, power supply wiring is required for supplying power from the power supply device 20 to the power transmission coil module 40. Therefore, when installing the non-contact power supply device 10, in addition to installing the power supply device 20 and the power transmission coil module 40, it is necessary to install the power supply wiring. In this embodiment, a measure is taken to reduce the workload of installing the non-contact power supply device 10.

[0011] As shown in FIG. 2, the power supply device 20 has an AC power supply 22, a DC power supply 24, a first AC output terminal ATP, a second AC output terminal ATN, a first DC output terminal DTP, and a second DC output terminal DTN. The AC power supply 22 and the DC power supply 24 are housed in a power supply housing 20a shown in FIG. 1. The first AC output terminal ATP, the second AC output terminal ATN, the first DC output terminal DTP, and the second DC output terminal DTN are exposed from the power supply housing 20a. The AC power supply 22 converts, for example, power supplied from an external power supply (not shown) into AC power of a desired high-frequency operating frequency, and outputs the converted AC power to the first AC output terminal ATP and the second AC output terminal ATN. The DC power supply 24 converts, for example, power supplied from an external power supply (not shown) into DC power of a desired operating voltage, and outputs the converted DC power to the first DC output terminal DTP and the second DC output terminal DTN. The DC power output from the DC power supply 24 is supplied to a control circuit 50, which is included in the power transmitting coil module 40 and will be described later, via wiring (not shown).

[0012] As shown in FIG. 1, in this embodiment, the power transmitting coil module 40 has a plurality of power transmitting circuits 41 and a first coil terminal MTP and a second coil terminal MTN as external connection terminals. The plurality of power transmitting circuits 41 are housed in a coil housing 40a. The first coil terminal MTP and the second coil terminal MTN are exposed from the coil housing 40a. The first AC output terminal ATP and the first coil terminal MTP are electrically connected by a first power supply wiring WP. The second AC output terminal ATN and the second coil terminal MTN are electrically connected by a second power supply wiring WN. Each power transmitting circuit 41 is electrically connected to each of the first coil terminal MTP and the second coil terminal MTN by a first internal wiring WPM and a second internal wiring WNM in the coil housing 40a.

[0013] As shown in FIG. 2, the power transmission circuit 41 includes a power transmission coil L1, a setting circuit 42, a control circuit 50, a first power transmission circuit terminal TP, and a second power transmission circuit terminal TN. In this embodiment, the setting circuit 42 is configured as a first circuit including a variable capacitance capacitor C1. The variable capacitance capacitor C1 has a function of making a power transmission resonant circuit 44 described later resonate at an operating frequency and making the power transmission resonant circuit 44 non-resonant at the operating frequency. The power transmission coil L1 is electrically connected to the power supply device 20. The setting circuit 42 is interposed between the power supply device 20 and the power transmission coil L1. Specifically, the variable capacitance capacitor C1 and the power transmission coil L1 are connected in series between the first power transmission circuit terminal TP and the second power transmission circuit terminal TN in this order. The variable capacitance capacitor C1 and the power transmission coil L1 configure a series resonant circuit. The resonant circuit configured by the variable capacitance capacitor C1 and the power transmission coil L1 is also called a power transmission resonant circuit 44. The variable capacitor C1 is also called a resonant capacitor. The multiple power transmitting coils L1 included in the power transmitting coil module 40 are connected to the AC power supply 22 in parallel.

[0014] The transmission coil L1 can be realized in a form in which a Litz wire is wound around the central axis of the coil, in a form in which printed wiring on a printed circuit board is formed in a C-shape or spiral shape around the central axis of the coil, or in a form in which printed circuit boards in which printed wiring is formed in a C-shape or spiral shape around the central axis of the coil are stacked and adjacent board wiring is made conductive to each other to form a spiral wiring.

[0015] The setting circuit 42 sets the power transmission coil L1 to either a power supply state or a standby state. The setting circuit 42 is separate from the power supply device 20. This can reduce the workload of the installation work of the non-contact power supply device 10, as described later in detail. The setting circuit 42 is disposed on a wiring that electrically connects the first coil terminal MTP as an external connection terminal and the power transmission coil L1. In this embodiment, the variable capacitance capacitor C1 is configured to be switchable between a first capacitance value and a second capacitance value smaller than the first capacitance value. The capacitance value of the variable capacitance capacitor C1 is switched between the first capacitance value and the second capacitance value by a switching signal Sig1 output from the control circuit 50. When the power transmission coil L1 and the power receiving coil L2 are magnetically coupled and the variable capacitance capacitor C1 has the first capacitance value, the power transmission resonant circuit 44 is in a resonant state at the operating frequency. On the other hand, when the variable capacitor C1 has the second capacitance value, the resonant frequency of the power transmitting resonant circuit 44 deviates from the operating frequency, and the power transmitting resonant circuit 44 enters a non-resonant state at the operating frequency.

[0016] The control circuit 50 outputs a switching signal Sig1 to the variable capacitor C1. The control circuit 50 includes a detection circuit 60 and a switching circuit 70. As described below, the detection circuit 60 detects a physical quantity whose value changes according to the distance between the power transmitting coil L1 and the power receiving coil L2, and outputs a detection signal Sig2 to the switching circuit 70. The detection circuit 60 includes a detection coil L3, a rectifier circuit 61, and a low-pass filter 62. The detection coil L3 is arranged in a manner that allows magnetic coupling with the power transmitting coil L1. When the magnetic flux density passing through the detection coil L3 changes, an induced current flows through the detection coil L3. The induced current flowing through the detection coil L3 is rectified by the rectifier circuit 51, and the high-frequency components are removed by the low-pass filter 52, and then output to the switching circuit 70 as a detection voltage. The detection voltage is also called a detection signal Sig2.

[0017] The switching circuit 70 compares the detection voltage output from the low-pass filter 52 with a reference voltage, and outputs a switching signal Sig1 if the detection voltage is equal to or higher than the reference voltage. The switching circuit 70 is realized by a microcomputer, a comparator, or the like.

[0018] The power receiving device 92 includes a power receiving coil L2, a power receiving capacitor C2, a rectifier circuit 96, and a battery 98. The power receiving coil L2 and the power receiving capacitor C2 form a resonant circuit. The resonant circuit formed by the power receiving coil L2 and the power receiving capacitor C2 is also called a power receiving resonant circuit 94. When the power transmitting coil L1 and the power receiving coil L2 are magnetically coupled, the resonant frequency of the power transmitting resonant circuit 44 and the resonant frequency of the power receiving resonant circuit 94 are set to be substantially the same. This allows contactless power supply to be performed by magnetic field resonance between the power transmitting coil L1 and the power receiving coil L2.

[0019] The rectifier circuit 96 converts the AC power output from the power receiving resonant circuit 94 into DC power and supplies it to the battery 98. In this embodiment, the battery 98 is a secondary battery that outputs DC power for driving a drive motor that is a drive source of the vehicle 90.

[0020] As shown in Fig. 1, the power transmission circuits 41 are arranged side by side along the extension direction of the road RS. In the contactless power supply system 1 according to this embodiment, a power receiving device 92 of a vehicle 90 traveling on the road RS is configured to receive power contactlessly from the nearest power transmission circuit 41. Specifically, when the power receiving coil L2 is present in the vicinity of the power transmission coil L1, the power transmission resonant circuit 44 is configured to be in a resonant state. On the other hand, when the power receiving coil L2 is not present in the vicinity of the power transmission coil L1, the power transmission resonant circuit 44 is configured to be in a non-resonant state.

[0021] 2, the degree of magnetic coupling between the power transmitting coil L1 and the power receiving coil L2 changes depending on the distance between the power transmitting coil L1 and the power receiving coil L2, and therefore the inductance of the power transmitting coil L1 changes. Specifically, when the power transmitting coil L1 and the power receiving coil L2 are arranged to have the same polarity, the shorter the distance between the power transmitting coil L1 and the power receiving coil L2, the greater the degree of magnetic coupling becomes, and therefore the greater the mutual inductance becomes, and the smaller the impedance of the power transmitting resonant circuit 44 becomes. Therefore, the shorter the distance between the power transmitting coil L1 and the power receiving coil L2, the greater the current value of the current flowing through the power transmitting resonant circuit 44 becomes, and therefore the greater the magnetic flux density, which is a physical quantity, generated by the power transmitting coil L1 becomes.

[0022] When the vehicle 90 approaches the target power transmission coil L1, the target power transmission coil L1 and the power receiving coil L2 face each other. The reference voltage used by the switching circuit 70 is set so that the detection voltage of the detection circuit 60 exceeds the reference voltage when the magnetic flux density of the opposing power transmission coil OL1 (FIG. 3), which is the power transmission coil L1 facing the power receiving coil L2, increases. Therefore, when the magnetic flux density of the opposing power transmission coil OL1 increases, a switching signal Sig1 is output from the switching circuit 70, and the capacitance value of the variable capacitance capacitor C1 connected to the opposing power transmission coil OL1 is set to the first capacitance value. On the other hand, the magnetic flux density of the non-opposing power transmission coil NL1 (FIG. 3), which is the power transmission coil L1 that does not face the power receiving coil L2, does not change significantly, so the detection voltage of the detection circuit 60 becomes equal to or lower than the reference voltage, and the capacitance value of the variable capacitance capacitor C1 connected to the non-opposing power transmission coil NL1 is set to the second capacitance value. Therefore, the power transmitting resonant circuit 44 having the opposing power transmitting coil OL1 is in a resonant state, and the power transmitting resonant circuit 44 having the non-opposing power transmitting coil NL1 is in a non-resonant state. As a result, non-contact power feeding can be performed by the power transmitting resonant circuit 44 having the opposing power transmitting coil OL1. Furthermore, since the second capacitance value is smaller than the first capacitance value, the impedance of the power transmitting resonant circuit 44 having the non-opposing power transmitting coil NL1 is larger than the impedance of the power transmitting resonant circuit 44 having the opposing power transmitting coil OL1. Therefore, the current flowing through the power transmitting resonant circuit 44 having the non-opposing power transmitting coil NL1 is smaller than the current flowing through the power transmitting resonant circuit 44 having the opposing power transmitting coil OL1. As a result, it is possible to reduce power loss in the power transmitting resonant circuit 44 having the non-opposing power transmitting coil NL1 and reduce leakage magnetic flux in the power transmitting resonant circuit 44 having the non-opposing power transmitting coil NL1.

[0023] As described above, the detection circuit 60 is used to detect whether the power transmitting coil L1 faces the power receiving coil L2. In this embodiment, the detection circuit 60 detects a change in the magnetic flux density generated by the power transmitting coil L1, and thereby the power transmitting coil L1 is switched between a power supply state and a standby state. Therefore, when the power receiving coil L2 approaches, the power transmitting coil L1 can be switched between a power supply state and a standby state with high response.

[0024] The state of the power transmitting coil L1 in which the power transmitting resonant circuit 44 is in a resonant state and wireless power is supplied to the power receiving device 92 by magnetic resonance between the power transmitting coil L1 and the power receiving coil L2 is also referred to as a power supplying state. The state of the power transmitting coil L1 in which the power transmitting resonant circuit 44 is in a non-resonant state and wireless power is not supplied to the power receiving device 92 is also referred to as a standby state.

[0025] 3, the "opposing" of the power transmitting coil L1 and the power receiving coil L2 includes not only the state (a) in which the entire power transmitting coil L1 and the entire power receiving coil L2 face each other in the direction of the coil central axis of the power transmitting coil L1, but also the state (b) in which a portion of the power transmitting coil L1 faces a portion of the power receiving coil L2. The "not facing" of the power transmitting coil L1 and the power receiving coil L2 means the state (c) in which no portion of the power transmitting coil L1 and the power receiving coil L2 faces each other in the direction of the central axis of the power transmitting coil L1.

[0026] 2, the power transmission circuit 41 according to the present embodiment includes the setting circuit 42, and thus can perform contactless power supply by the opposing power transmission coil OL1 and can suppress the current flowing through the non-opposing power transmission coil NL1. Furthermore, since the setting circuit 42 is separate from the power supply device 20, when a new power transmission coil L1 is added by connecting it in parallel with the power supply device 20, the power supply wiring for supplying power to the new power transmission coil L1 can be branched from the first power supply wiring WP and the second power supply wiring WN. Therefore, the new power transmission coil L1 can be added without directly running the power supply wiring from the power supply device 20, and therefore the workload of the installation work of the contactless power supply device 10 can be reduced.

[0027] In addition, since the setting circuit 42 is separate from the power supply device 20, the power supply wiring for supplying power from the power supply device 20 to the power transmission coil L1 can be limited to the first power supply wiring WP and the second power supply wiring WN. Unlike the present embodiment, the setting circuit 42 can be provided integrally with the power supply device 20. However, in this configuration, it is necessary to provide a wiring W1 connecting the setting circuit 42 and the power transmission coil L1 and a wiring W2 connecting the power transmission coil L1 and the AC power source 22 for each power transmission coil L1. That is, in the configuration in which a plurality of power transmission coils L1 are connected in parallel to the AC power source 22 as in the present embodiment, two power supply wirings are required for each of the plurality of power transmission coils L1 connected in parallel to the AC power source 22. Specifically, when there are four power transmission circuits 41, eight power supply wirings are required. In this regard, in the present embodiment, since the setting circuit 42 is separate from the power supply device 20, it is possible to supply power to the plurality of power transmission coils L1 using two power supply wirings, the first power supply wiring WP and the second power supply wiring WN. Also, the terminals for AC power can be limited to two, the first coil terminal MTP and the second coil terminal MTN. This can reduce the workload of installing the non-contact power supply device 10. The distance between the setting circuit 42 and the power transmission coil L1 is preferably shorter than the distance between the setting circuit 42 and the power supply device 20. This is because the length of the wiring W1 and the wiring W2 required for each of the multiple power transmission coils L1 can be shorter than the length of the first power supply wiring WP and the second power supply wiring WN.

[0028] According to the first embodiment described above, since the setting circuit 42 is separate from the power supply device 20, the workload involved in the installation work of the non-contact power supply device 10 can be reduced. Furthermore, even in a configuration in which a plurality of power transmission coils L1 are connected in parallel to the AC power supply 22, since the setting circuit 42 is separate from the power supply device 20, the power supply wiring drawn from the power supply device 20 can be limited to the first power supply wiring WP and the second power supply wiring WN. This reduces the workload involved in the installation work of the non-contact power supply device 10. Furthermore, the power transmission coil module 40 has the setting circuit 42. As a result, the power transmission coil L1 and the setting circuit 42 can be handled as an integrated unit, so that the workload involved in the installation work of the non-contact power supply device 10 can be reduced. Furthermore, the setting circuit 42 is configured to include a variable capacitance capacitor C1. As a result, the power transmission coil L1 can be set to either a power supply state or a standby state by switching the capacitance value of the variable capacitance capacitor C1 to either a first capacitance value or a second capacitance value. Moreover, the detection circuit 60 and the switching circuit 70 are disposed in the power transmitting coil module 40. This allows the detection circuit 60 and the switching circuit 70 to be handled integrally with the power transmitting coil L1, thereby reducing the workload associated with the installation of the contactless power supply device 10.

[0029] B. Second embodiment: A power transmission coil module 240 included in a non-contact power supply device 210 according to the second embodiment shown in FIG. 4 is different from the power transmission coil module 40 according to the first embodiment in the number of power transmission circuits 41 included. The power transmission coil module 40 according to the first embodiment has a plurality of power transmission circuits 41, whereas the power transmission coil module 240 according to the present embodiment has one power transmission circuit 241. The power transmission circuit 241 according to the second embodiment is different from the first embodiment in that it does not have a control circuit 50 and the setting circuit 242 is configured to include a variable capacitor C21 whose capacitance value changes in response to a change in magnetic flux. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted as appropriate.

[0030] The power transmitting coil module 240 has a power transmitting circuit 241, two first coil terminals MTP, and two second coil terminals MTN. The two first coil terminals MTP are electrically connected to each other within the power transmitting coil module 240. Similarly, the two second coil terminals MTN are electrically connected to each other within the power transmitting coil module 240. The first AC output terminal ATP and the first coil terminal MTP of one power transmitting coil module 240 are electrically connected by a first power supply wiring WP. The second AC output terminal ATN and the second coil terminal MTN of one power transmitting coil module 240 are electrically connected by a second power supply wiring WN. The power transmitting coil module 240 that is not connected to the power supply device 20 by the first power supply wiring WP and the second power supply wiring WN is electrically connected to the power transmitting coil module 240 that is connected to the power supply device 20 by the first power supply wiring WP and the second power supply wiring WN by a third wiring W3 and a fourth wiring W4.

[0031] In the present embodiment, the setting circuit 242 is separate from the power supply device 20, and therefore the power transmission coil L1 can be supplied with power using two power supply wires, the first power supply wire WP and the second power supply wire WN. As described above, the power transmission coil modules 240 are arranged in the direction in which the road RS extends, and therefore the third wire W3 and the fourth wire W4 are shorter than the first power supply wire WP and the second power supply wire WN. Therefore, the power transmission coils L1 can be supplied with power by electrically connecting adjacent power transmission coil modules 240 to each other using the third wire W3 and the fourth wire W4, which are shorter than the first power supply wire WP and the second power supply wire WN. Therefore, the workload of the installation work of the non-contact power supply device 10 can be reduced.

[0032] As shown in FIG. 5, in this embodiment, the power transmission coil L1 and the variable capacitance capacitor C1 are arranged on the same printed circuit board 100. The power transmission coil L1 is realized by a printed wiring 110, which is formed in a spiral shape on the printed circuit board 100 and is shown by hatching. The variable capacitance capacitor C1 is mounted inside the power transmission coil L1. Here, the inside means a space in the shape of a square column or cylinder, with the area surrounded by the conductors constituting the power transmission coil L1 as the bottom surface and the coil central axis direction as the height direction, within a range through which the magnetic flux generated by the power transmission coil L1 passes. The range through which the magnetic flux generated by the power transmission coil L1 passes can be, for example, a range with the height equal to the diameter or width of the power transmission coil L1. Since the power transmission coil L1 and the variable capacitance capacitor C1 are arranged on the same printed circuit board 100, printed wiring can be used to connect the power transmission coil L1 and the variable capacitance capacitor C1. Therefore, since there is no need to use a terminal or a harness for connecting the power transmitting coil L1 and the variable capacitor C1, the power transmitting resonant circuit 244 can be realized with a simple configuration.

[0033] The variable capacitor C21 has a characteristic that the capacitance value increases as the magnetic flux density penetrating the variable capacitor C21 increases. The variable capacitor C21 has a capacitance value characteristic that the power transmission resonance circuit 244 is in a resonant state at the operating frequency when the power transmission coil L1 faces the power receiving coil L2. Therefore, the variable capacitor C21 connected to the non-opposing power transmission coil NL1 has a smaller capacitance value than the variable capacitor C21 connected to the opposing power transmission coil OL1 because the magnetic flux density generated by the power transmission coil L1 is small. Therefore, as in the first embodiment, the impedance of the power transmission circuit 241 having the non-opposing power transmission coil NL1 increases, making it difficult for a current to flow. Therefore, according to this configuration, the impedance of the power transmission resonance circuit 244 can be switched without the control circuit 50.

[0034] According to the second embodiment described above, the same effects as those of the above embodiment can be obtained, and since the setting circuit 242 is disposed inside the power transmitting coil L1, it is possible to make the power transmitting circuit 241 compact. Furthermore, since the power transmitting coil L1 and the setting circuit 242 are disposed on the same board, it is possible to use printed wiring as wiring for connecting the power transmitting coil L1 and the setting circuit 242.

[0035] C. Third embodiment: 6, the contactless power supply device 310 according to the third embodiment includes a power supply device 20, a power transmission coil module 340, a setting circuit module 380, a switching circuit 370, and an imaging unit 360. The contactless power supply device 310 according to this embodiment differs from the first embodiment in that the setting circuit 42 included in the power transmission coil module 40 is provided separately from the power transmission coil module 340. The same components as those in the above embodiments are denoted by the same reference numerals, and detailed descriptions thereof will be omitted as appropriate.

[0036] The setting circuit module 380 has a plurality of setting circuits 42, a first input terminal ZTPI, a second input terminal ZTNI, a plurality of first output terminals ZTPO, and a plurality of second output terminals ZTNO. The plurality of setting circuits 42 are housed in a housing (not shown) of the setting circuit module 380. Each terminal is provided exposed from the housing. Each variable capacitor C1 is disposed on a wiring that connects the first input terminal ZTPI and the first output terminal ZTPO. The second input terminal ZTNI and each second output terminal ZTNO are electrically connected by wiring within the housing.

[0037] The power transmitting coil module 340 has a plurality of power transmitting coils L1, a plurality of first coil terminals MTP, and a plurality of first coil terminals MTP. The power transmitting coil L1 is connected between the first coil terminal MTP and the first coil terminal MTP. The first output terminal ZTPO and the first coil terminal MTP are connected by wiring, and the second output terminal ZTNO and the second coil terminal MTN are connected by wiring. In this embodiment, the plurality of setting circuit modules 380 and the plurality of power transmitting coil modules 340 are electrically connected to one AC power source 22. The plurality of setting circuit modules 380 are electrically connected to the AC power source 22 by branching the power source wiring from each of the first power source wiring WP and the second power source wiring WN.

[0038] The imaging unit 360 includes a camera that captures an image of the vehicle 90 traveling on the road RS, and transmits the captured image to the switching circuit 370. The switching circuit 370 uses the transmitted image to identify the power transmitting coil L1 close to the vehicle 90, and inputs a switching signal Sig1 to each variable capacitor C1 so as to bring the power transmitting coil L1 close to the vehicle 90 into a resonant state and bring the other power transmitting coils L1 into a non-resonant state.

[0039] In this embodiment, the setting circuit module 380 including the setting circuit 42 is separate from the power transmission coil module 340 including the power transmission coil L1, so that the setting circuit 42 can be arranged at a location away from the power transmission coil L1. The power transmission coil L1 is arranged on the road RS, and the setting circuit 42 is arranged at a location different from the road RS. Since the road RS is a road on which vehicles travel, when the setting circuit 42 is arranged on the road RS, the setting circuit 42 receives an external force due to the travel of the vehicle. Therefore, since the setting circuit 42 is arranged at a location different from the road RS, the external force received by the setting circuit 42 can be reduced compared to when the setting circuit 42 is arranged on the road RS on which the vehicle 90 travels. Therefore, deterioration of the setting circuit 42 can be suppressed. The location where the setting circuit 42 is arranged is preferably a location where vehicles pass by infrequently, for example, a sidewalk or a lane. In addition, since the setting circuit 42 does not need to be arranged at a location opposite the power receiving coil L2, it may be arranged on the ground in addition to being buried underground. When the setting circuit 42 is arranged on the ground, maintenance work related to the setting circuit 42 can be easily performed.

[0040] According to the third embodiment described above, the same effects as those of the above-mentioned embodiments can be obtained. In addition, since the power transmitting coil L1 is disposed on the road RS and the setting circuit 42 is disposed at a position different from the road RS, it is possible to perform contactless power supply to the vehicle 90 traveling on the road RS and to suppress deterioration of the setting circuit 42.

[0041] D. Fourth embodiment: 7, a contactless power supply device 410 according to the fourth embodiment is the same as the third embodiment in that it includes an imaging unit 360 and a switching circuit 370, and a switching signal Sig1 output from the switching circuit 370 is input to each setting circuit 442. A power transmission circuit 441 according to the fourth embodiment has a different circuit configuration from the power transmission circuit 41 according to the first embodiment. The same components as those in the above embodiments are denoted by the same reference numerals, and detailed descriptions thereof will be omitted as appropriate.

[0042] The power transmission circuit 441 includes a power transmission coil L1, a fourth capacitance C4, a setting circuit 442, a first power transmission circuit terminal TP, a second power transmission circuit terminal TN, and a third power transmission circuit terminal TS. The power transmission coil L1 and the fourth capacitance C4 are connected in parallel between the first power transmission circuit terminal TP and the second power transmission circuit terminal TN. The power transmission coil L1 and the fourth capacitance C4 configure a power transmission resonance circuit 444, which is a parallel resonance circuit. In this embodiment, since the fourth capacitance C4 is connected in parallel with the power transmission coil L1, a resonance system that contributes to the power factor is closed between the fourth capacitance C4 and the power transmission coil L1, and therefore, a decrease in the power factor of the AC power output from the AC power source 22 due to a parasitic inductance component of the wiring can be suppressed.

[0043] The setting circuit 442 is configured as a second circuit including a first switch SW1 as a second circuit switch. The first switch SW1 is disposed on a wiring that connects the first power transmission circuit terminal TP and the power transmission coil L1. The first switch SW1 switches the connection between the first power transmission circuit terminal TP and the power transmission coil L1 between a conductive state and a non-conductive state according to the voltage value of a switching signal Sig1. In this embodiment, the first switch SW1 is configured of two N-channel MOS-FETs that are connected in series so that their source terminals are connected. The switching signal Sig1 is input to the gate terminals of the two MOS-FETs. When a high-level switching signal Sig1 is input to the first switch SW1, the first switch SW1 is in a conductive state as a first state, and the first power transmission circuit terminal TP and the power transmission coil L1 are conductive. As a result, the power transmission coil L1 is set to a power supply state. On the other hand, when a low-level switching signal Sig1 is input to the first switch SW1, the first switch SW1 is in a non-conducting state as a second state, and the first power transmitting circuit terminal TP and the power transmitting coil L1 are not conductive. This sets the power transmitting coil L1 to a standby state. Note that the configuration of the first switch SW1 is not limited to the above. For example, the first switch SW1 may be configured by adding a separate diode in the same direction as the body diode of the MOS-FET shown in FIG. 7.

[0044] The switching circuit 370 inputs a high-level switching signal Sig1 to the power transmission circuit 441 including the power transmission coil L1 facing the power receiving coil L2, and inputs a low-level switching signal Sig1 to the power transmission circuit 441 including the power transmission coil L1 not facing the power receiving coil L2. As a result, AC power is supplied to the power transmission coil L1 facing the power receiving coil L2, and the power transmission resonant circuit 444 is in a resonant state. On the other hand, AC power is not supplied to the power transmission coil L1 not facing the power receiving coil L2. As a result, the power receiving device 92 is contactlessly fed with power from the power transmission coil L1 facing the power receiving coil L2.

[0045] In this embodiment, the switching circuit 370 is included in the power supply device 420. Specifically, the switching circuit 370 is housed in the power supply housing 20a. The power supply housing 20a (FIG. 1) is provided with a plurality of signal output terminals STP. The power transmission circuit module 440 is provided with a plurality of coil signal terminals MSIG. The signal output terminal STP and the coil signal terminal MSIG are connected by signal wiring. The power transmission circuit module 440 also has a plurality of power transmission circuits 441. As in the first embodiment, the first power transmission circuit terminal TP and the second power transmission circuit terminal TN of each power transmission circuit 441 are connected to the first coil terminal MTP and the second coil terminal MTN, respectively, in the power transmission circuit module 440. The third power transmission circuit terminal TS of each power transmission circuit 441 is connected to each coil signal terminal MSIG in the power transmission circuit module 440. By providing the switching circuit 370 in the power supply device 420, the switching circuit 370 can be handled integrally with the power supply device 420, and therefore the workload of installing the contactless power supply device can be reduced.

[0046] According to the fourth embodiment described above, the same effects as those of the above-mentioned embodiments can be obtained. In addition, since the switching circuit 370 is disposed in the power supply device 420, the workload of installing the contactless power supply device can be reduced.

[0047] E. Fifth embodiment: 8, the contactless power supply device 510 according to the fifth embodiment is different from the contactless power supply device 10 according to the first embodiment in the circuit configuration of the power transmission circuit 541. The same components as those in the above embodiments are denoted by the same reference numerals, and detailed description thereof will be omitted as appropriate.

[0048] The power transmission circuit 541 includes a power transmission coil L1, a setting circuit 542, a control circuit 50, a first power transmission circuit terminal TP, and a second power transmission circuit terminal TN. The setting circuit 542 is configured as a third circuit including a first switch SW1 as a third circuit switch, a fifth capacitance C5, and a sixth capacitance C6. The first switch SW1, the fifth capacitance C5, and the power transmission coil L1 are connected in series in this order between the first power transmission circuit terminal TP and the second power transmission circuit terminal TN. The sixth capacitance C6 is connected in parallel with the connection body of the first switch SW1 and the fifth capacitance C5. The capacitance value of the sixth capacitance C6 is smaller than the capacitance value of the fifth capacitance C5. A switching signal Sig1 is input from the control circuit 50 to the first switch SW1.

[0049] The first switch SW1 switches the fifth capacitance C5, which is a part of the fifth capacitance C5 and the sixth capacitance C6, which have different capacitance values, between a conducting state and a non-conducting state. Specifically, when a high-level switching signal Sig1 is input to the first switch SW1, the first switch SW1 becomes conductive, and a current flows through the fifth capacitance C5. Here, the combined capacitance of the fifth capacitance C5 and the sixth capacitance C6 and the inductance of the power transmitting coil L1 are set to values ​​that create a resonance state at the operating frequency. As a result, when the first switch SW1 becomes conductive, the fifth capacitance C5, the sixth capacitance C6, and the power transmitting coil L1 form a power transmitting resonant circuit 544, which is a series resonant circuit. On the other hand, when a low-level switching signal Sig1 is input to the first switch SW1, the first switch SW1 becomes non-conductive, and the fifth capacitance C5 becomes non-conductive. The resonant frequency of the resonant circuit formed by the sixth capacitance C6 and the power transmitting coil L1 in the conductive state deviates from the operating frequency, so that the power transmitting coil L1 is in a standby state. In addition, since the capacitance value of the sixth capacitance C6 is smaller than the capacitance value of the fifth capacitance C5, when the first switch SW1 is in a non-conductive state, the impedance of the power transmitting circuit 541 with respect to the input AC power becomes large, and the current flowing through the power transmitting resonant circuit 544 is suppressed.

[0050] According to the embodiment described above, the same effects as those described above can be achieved, and the setting circuit 542 having the fifth capacitance C5 and the sixth capacitance C6 having different capacitance values ​​and the first switch SW1 can set the transmitting coil L1 to either a power supply state or a standby state.

[0051] F. Sixth embodiment: 9, a contactless power supply device 610 according to the sixth embodiment differs from the first embodiment in the configuration of a power supply device 620 and the configuration of a power transmission circuit 641. The same components as those in the above embodiments are denoted by the same reference numerals, and detailed description thereof will be omitted as appropriate.

[0052] The power supply device 620 according to this embodiment has an AC power supply 22, but does not have the DC power supply 24 according to the first embodiment. The power transmission circuit 641 is configured to include a conversion circuit 624 that converts AC power to DC power and supplies the DC power to the control circuit 50. The conversion circuit 624 is realized by, for example, an AC / DC converter. As a result, compared to a configuration in which the DC power supply 24 is arranged in the power supply device 20 and the DC power supply 24 and the power transmission coil module 40 are connected by power supply wiring, it is possible to supply DC power to the control circuit 50 without laying power supply wiring for supplying DC power, and therefore the workload of installation work can be reduced.

[0053] According to the sixth embodiment described above, the same effects as those of the above embodiments can be achieved, and DC power can be supplied to the control circuit 50 without laying power supply wiring for supplying DC power, thereby reducing the workload of installation work.

[0054] G. Seventh embodiment: 10, the contactless power supply device 710 according to the seventh embodiment has a circuit configuration similar to that of the sixth embodiment. The power transmitting coil module 640 according to the sixth embodiment has a plurality of power transmitting circuits 641, whereas the power transmitting coil module 740 according to the seventh embodiment has one power transmitting circuit 741, which is different from the sixth embodiment. The same components as those in the above embodiments are denoted by the same reference numerals, and detailed description thereof will be omitted as appropriate.

[0055] The power transmitting circuit 741 has a power transmitting coil L1, a setting circuit 42, a control circuit 50, and a conversion circuit 624. As in the second embodiment, the setting circuit 42, the control circuit 50, and the conversion circuit 624 are arranged inside the power transmitting coil L1. In FIG. 10, the aspect of the power transmitting coil L1 is represented by a hatched figure. As shown in the hatched figure, each circuit is arranged inside the spiral conductor that constitutes the power transmitting coil L1. By arranging each circuit inside the power transmitting coil L1, the power transmitting circuit 741 can be made compact.

[0056] H. Other embodiments: (H1) In each of the above embodiments, the power receiving device 92 is mounted on a vehicle 90 such as an electric vehicle. The vehicle on which the power receiving device 92 is mounted may be an AGV (automated guided vehicle). In the case where the power receiving device 92 is mounted on an AGV and the setting circuit 42 is configured separately from the power transmitting coil L1 as in the third embodiment, the setting circuit 42 may be installed in a position different from the aisle, where the AGV does not travel, for example, below a storage shelf.

[0057] (H2) In the first embodiment, the detection coil L3 detects the magnetic flux generated by the power transmitting coil L1, which is a physical quantity whose value changes in response to the distance between the power transmitting coil L1 and the power receiving coil L2. The physical quantity whose value changes in response to the distance between the power transmitting coil L1 and the power receiving coil L2 may be not only the magnetic flux but also the voltage of the power transmitting coil L1, the current of the power transmitting coil L1, the voltage of the resonant capacitor, or a magnetic field or an electric field near the power transmitting coil L1. In this configuration, the detection circuit 60 may be configured to include a detector for detecting each physical quantity.

[0058] (H3) In the first embodiment, the power transmission circuit 41 has a variable capacitor C1 and a power transmission coil L1. The circuit configuration of the power transmission circuit 41 is not limited to the above. For example, as shown in FIG. 11, the power transmission circuit 841 may be configured by adding the variable capacitor C1 and the power transmission coil L1, and arranging a closed circuit formed by connecting a tertiary coil L10 and a capacitor C10 in series in the vicinity of the power transmission coil L1 at a position where the tertiary coil L10, the power receiving coil L2, and the power transmission coil L1 can be magnetically coupled to each other. By setting the capacitance values ​​of the variable capacitor C1, the power receiving capacitor C2, and the capacitor C10 so that the imaginary component of the input impedance of the power transmission circuit 841 is small, it is possible to suppress a decrease in the power factor of the AC power output from the AC power source 22. 12, the power transmitting circuit 941 may be configured by, in addition to the variable capacitor C1 and the power transmitting coil L1, arranging a circuit including a tertiary coil L20 connected in series with the power transmitting coil L1 and a capacitor C20 connected in parallel with the tertiary coil L20 between the power transmitting coil L1 and the second power transmitting circuit terminal TN at a position where the tertiary coil L20, the power receiving coil L2, and the power transmitting coil L1 can be magnetically coupled to each other. In this circuit configuration, similar to the above, the capacitance values ​​of the variable capacitor C1, the power receiving capacitor C2, and the capacitor C20 are set so that the imaginary component of the input impedance of the power transmitting circuit 941 is reduced, thereby suppressing a decrease in the power factor of the AC power output from the AC power source 22.

[0059] (H4) In the first embodiment, the detection coil L3 is arranged in a form that allows magnetic coupling with the power transmission coil L1. When the power transmission circuit 41 is configured to include a separate coil that can be magnetically coupled with the power transmission coil L1 in addition to the power transmission coil L1, the detection coil L3 may be arranged in a form that allows magnetic coupling with the separate coil.

[0060] (H5) In the first embodiment, the switching circuit 70 outputs the switching signal Sig1 using the detection signal Sig2 output by the detection circuit 60. In addition to this configuration, a configuration in which the switching signal Sig1 is output by using the detection signal Sig2 output by the detection circuit 60 and another external signal may be used. Specifically, the other external signal is, for example, a signal for switching the power transmitting coil L1 between a power supply state and a standby state by detecting an abnormal state, regardless of the position of the power transmitting coil L1.

[0061] (H6) In the first embodiment, the multiple power transmitting coils L1 are connected in parallel to the AC power supply 22. The contactless power supply device may have a configuration including one power transmitting coil L1. In this configuration, when a new power transmitting coil L1 is added by connecting it in parallel to the AC power supply 22, power supply wiring for supplying power to the new power transmitting coil L1 can be branched from the first power supply wiring WP and the second power supply wiring WN, thereby reducing the installation workload.

[0062] The present disclosure is not limited to the above-mentioned embodiments and modifications, and can be realized in various configurations without departing from the spirit of the present disclosure. For example, the technical features in the embodiments and modifications corresponding to the technical features in each aspect described in the Summary of the Invention column can be appropriately replaced or combined in order to solve some or all of the above-mentioned problems or to achieve some or all of the above-mentioned effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted.

[0063] I. Other forms: (1) According to a first aspect of the present disclosure, there is provided a contactless power supply device that supplies power to a power receiving device in a contactless manner, the contactless power supply device including a power supply device that outputs AC power, a power transmission coil that is electrically connected to the power supply device, and a setting circuit that is interposed between the power supply device and the power transmission coil and sets the power transmission coil to either a power supply state or a standby state, the setting circuit being separate from the power supply device.

[0064] (2) According to a second aspect, the contactless power supply device according to the first aspect further includes a power transmission coil module having one or more of the power transmission coils, the power transmission coil module having an external connection terminal for electrically connecting to the power supply device, wiring electrically connecting the external connection terminal and the power transmission coil, and the setting circuit arranged on the wiring.

[0065] (3) According to a third aspect, in the contactless power supply device according to the second aspect, the setting circuit is disposed inside the power transmission coil.

[0066] (4) According to a fourth aspect, in the contactless power supply device according to the third aspect, the power transmission coil and the setting circuit are disposed on a same substrate.

[0067] (5) According to a fifth aspect, in the wireless power supply device according to the first aspect, the power transmission coil is disposed in a passageway along which a vehicle travels, and the setting circuit is disposed at a position different from the passageway.

[0068] (6) According to a sixth aspect, in the contactless power supply device according to any one of the first to fifth aspects, the setting circuit is configured to include any one of a first circuit having a variable capacitor, and setting the capacitance value of the variable capacitor to a first capacitance value to set the power supplying state and the standby state by setting the capacitance value to a second capacitance value different from the first capacitance value; a second circuit having a second circuit switch for switching whether or not to supply current between the AC power and the power transmitting coil, and setting the power supplying state by turning the second circuit switch to a conducting state and setting the standby state by turning the second circuit switch to a non-conducting state; and a third circuit having a plurality of capacitors having different capacitance values ​​from each other and a third circuit switch for switching some of the plurality of capacitors between a conducting state and a non-conducting state, and setting the power supplying state by turning the third circuit switch to one of a conducting state and a non-conducting state and setting the standby state by turning the third circuit switch to the other of a conducting state and a non-conducting state.

[0069] (7) According to a seventh aspect, in the non-contact power supply device according to any one of the first to fourth aspects, the power transmission coil is provided in plurality, and the plurality of power transmission coils are connected in parallel to the power supply device.

[0070] (8) According to an eighth aspect, in the contactless power supply device according to any one of the first to seventh aspects, the setting circuit is switchable between a first state and a second state, and sets the power supply state by becoming the first state, and sets the standby state by becoming the second state. The contactless power supply device further includes a switching circuit that outputs a switching signal to instruct the setting circuit to switch between the first state and the second state, and the switching circuit is disposed within the power supply device.

[0071] (9) According to a ninth aspect, in the contactless power supply device according to any one of the first to seventh aspects, the setting circuit is switchable between a first state and a second state, and sets the power supplying state by becoming the first state, and sets the standby state by becoming the second state. The contactless power supply device further includes a detection circuit that detects a physical quantity whose value changes depending on a distance between the power transmitting coil and a power receiving coil of the power receiving device and outputs a detection signal, and a switching circuit that uses the detection signal to output a switching signal to instruct the setting circuit to switch to either the first state or the second state, and the detection circuit and the switching circuit are arranged in the power transmitting coil module.

[0072] (10) According to a tenth aspect, the contactless power supply device according to the ninth aspect further includes a conversion circuit that converts the AC power into DC power and supplies the DC power to at least one of the detection circuit and the switching circuit, and the conversion circuit is disposed in the power transmission coil module. [Explanation of symbols]

[0073] 10,210 to 710... non-contact power supply device, 20,420,620... power supply device, 42,242,542... setting circuit, 92... power receiving device, L1... power transmission coil

Claims

1. A non-contact power supply device (10, 210 to 710) that supplies power to a power receiving device (92) in a non-contact manner, A power supply device (20, 420, 620) that outputs AC power; A power transmission coil (L1) electrically connected to the power supply device; a setting circuit (42, 242, 442, 542) interposed between the power supply device and the power transmitting coil for setting the power transmitting coil to one of a power supply state and a standby state; A power transmission coil module (40, 240, 340, 640, 740) having one or more power transmission coils, The power supply device has a power supply housing (20a), the setting circuit is separate from the power supply device, The power transmission coil module includes: A coil housing (40a) that is separate from the power supply housing; an external connection terminal (MTP, MTN) for electrically connecting to the power supply device, the external connection terminal being exposed from the coil housing; Wiring electrically connecting the external connection terminal and the power transmitting coil; The setting circuit is disposed on the wiring, The wiring and the setting circuit are housed in the coil housing, The setting circuit includes: a first circuit having a variable capacitance capacitor (C1), the first circuit setting the capacitance value of the variable capacitance capacitor to a first capacitance value to set the power supply state, and setting the capacitance value of the variable capacitance capacitor to a second capacitance value different from the first capacitance value to set the standby state; a third circuit switch (SW1) that switches a portion of the plurality of capacitors between a conducting state and a non-conducting state, and sets the third circuit switch to one of the conducting state and the non-conducting state to set the power supplying state, and sets the third circuit switch to the other of the conducting state and the non-conducting state to set the third circuit switch to the standby state.

2. The non-contact power supply device according to claim 1, The setting circuit is disposed inside the power transmission coil.

3. The non-contact power supply device according to claim 2, The wireless power supply device, wherein the power transmission coil and the setting circuit are arranged on the same substrate.

4. The non-contact power supply device according to claim 1, The power transmitting coil is disposed in a passage (RS) along which a vehicle travels, The non-contact power supply device, wherein the setting circuit is disposed at a position different from the passage.

5. The non-contact power supply device according to any one of claims 1 to 3, A plurality of the power transmission coils are provided, The plurality of power transmission coils are connected in parallel to the power supply device.

6. The non-contact power supply device according to any one of claims 1 to 3, the setting circuit is switchable between a first state and a second state, and sets the power supply state by being in the first state, and sets the standby state by being in the second state; The non-contact power supply device further comprises: a switching circuit (370) that outputs a switching signal to instruct the setting circuit to switch to either the first state or the second state; The switching circuit is disposed within the power supply device.

7. A non-contact power supply device (10, 210 to 710) that supplies power to a power receiving device (92) in a non-contact manner, A power supply device (20, 420, 620) that outputs AC power; A power transmission coil (L1) electrically connected to the power supply device; a setting circuit (42, 242, 442, 542) interposed between the power supply device and the power transmitting coil for setting the power transmitting coil to one of a power supply state and a standby state; A power transmission coil module (40, 240, 340, 640, 740) having one or more power transmission coils, The power supply device has a power supply housing (20a), the setting circuit is separate from the power supply device, The power transmission coil module includes: A coil housing (40a) that is separate from the power supply housing; an external connection terminal (MTP, MTN) for electrically connecting to the power supply device, the external connection terminal being exposed from the coil housing; Wiring electrically connecting the external connection terminal and the power transmitting coil; The setting circuit is disposed on the wiring, The wiring and the setting circuit are housed in the coil housing, the setting circuit is switchable between a first state and a second state, and sets the power supply state by being in the first state, and sets the standby state by being in the second state; The non-contact power supply device further comprises: a detection circuit (60) that detects a physical quantity whose value changes in response to the distance between the power transmitting coil and a power receiving coil of the power receiving device and outputs a detection signal; a switching circuit (70) that uses the detection signal to output a switching signal to instruct the setting circuit to switch to either the first state or the second state, The detection circuit and the switching circuit are disposed in the power transmitting coil module.

8. The non-contact power supply device according to claim 7, further comprising: a conversion circuit (624) that converts the AC power into DC power and supplies the DC power to at least one of the detection circuit and the switching circuit; The conversion circuit is disposed in the power transmission coil module.

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