Non-contact power transmission system, non-contact power supply system, and non-contact power supply method

Abstract

A non-contact power transmission system (200) is provided with a plurality of power transmission devices (50) capable of transmitting power to a power reception device (30) in a non-contact manner. The power transmission device is provided with a power transmission coil (51) that is provided within the movable range of the moving body (20) and that transmits power to the power receiving device of the moving body in a non-contact manner. Comprises: a main power supply line (RFP) for supplying AC power of a first voltage for power transmission to a plurality of power transmission devices; and a DC power supply unit (60) that receives the supply of AC power from the main power supply line and outputs power of a second voltage that is lower than the first voltage and is used for controlling the inside of the power transmission device. Consequently, a non-contact power transmission system in which the power supply for controlling the power transmission device is simplified can be realized.

Description

Citation of related applications

[0001] This application is based on patent application No. 2022-99079 filed in Japan on June 20, 2022 and patent application No. 2023-69851 filed in Japan on April 21, 2023, claims their priority, and incorporates the entire contents of these patent applications into this specification by reference. Technical Field

[0002] The present disclosure relates to a technology for transmitting power in a contactless manner. Background Art

[0003] In the past, various contactless power supply technologies have been proposed for supplying power to a moving object in a non-contact manner from a running surface. For example, Japanese Patent Publication No. 2017-51074 shows a contactless power supply structure that receives power from a primary power supply line on the road side on which the moving object moves via a power supply transformer. In this case, multiple power transmission devices are arranged on the running surface of the moving object, and the power transmission device to be supplied is switched according to the position of the moving object.

[0004] However, if the switching of power supply from such a power transmission device, specifically the power transmission coil, is to be controlled, a power supply for control is required. Therefore, in addition to the main power supply, a power supply line for the control power supply is required, but corresponding wiring is required, which increases the man-hours for laying the power transmission device. Summary of the invention

[0005] The present disclosure can be implemented as modes or application examples.

[0006] (1) The first mode of the present disclosure is a mode as a contactless power transmission system. The contactless power transmission system includes: a plurality of power transmission devices, the plurality of power transmission devices including power transmission coils, the power transmission coils being arranged within the movable range of a moving body and transmitting power to a power receiving device of the moving body in a contactless manner; a main power line, the main power line supplying AC power of a first voltage for the power transmission to the plurality of power transmission devices; and a DC power supply unit, the DC power supply unit receiving the supply of AC power from the main power line and outputting power of a second voltage which is a voltage lower than the first voltage and used for control within the power transmission device.

[0007] (2) The second mode of the present disclosure is a mode as a contactless power supply system. The contactless power supply system includes: a power receiving device, the power receiving device having a power receiving coil disposed inside a moving body; a plurality of power transmitting devices, the plurality of power transmitting devices including a power transmitting coil disposed within a movable range of the moving body and magnetically coupling with the power receiving coils of the power receiving devices of the moving body to transmit power in a contactless manner; a main power line, the main power line supplies AC power of a first voltage for the power transmission to the plurality of power transmitting devices; and a DC power supply unit, the DC power supply unit receives the supply of AC power from the main power line and outputs power of a second voltage, which is a voltage lower than the first voltage, for control within the power transmitting device.

[0008] (3) In addition, the third mode of the present disclosure is a mode as a contactless power supply method. The contactless power supply method supplies AC power of a first voltage to a plurality of power transmission devices provided within a movable range of a moving body via a main power line, and a DC power supply unit that receives the supply of AC power from the main power line outputs power of a second voltage that is a voltage lower than the first voltage, which is an operating voltage of a control unit in the power transmission device, and under the control of the control unit, at least one of the plurality of power transmission devices uses the AC power of the first voltage to supply high-frequency AC power to a power transmission coil provided in the power transmission device, and transmits power to a power receiving coil of a power receiving device of the moving body via the power transmission coil in a contactless manner.

[0009] According to these methods, the DC power of the second voltage can be used to control the power transmission device, which can reduce the work and time of laying multiple power transmission devices. In addition, the present disclosure can be implemented in various ways, for example, in addition to the power supply device, it can also be implemented in various ways such as a design method of a power transmission system. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] 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 schematic configuration diagram of a contactless power supply system including a power receiving device according to an embodiment. Figure 2 This is a block diagram illustrating the configuration of a main power supply device. Figure 3 It is an explanatory diagram showing a schematic configuration of a power transmitting device and a power receiving device. Figure 4 This is a schematic structural diagram of a power transmission device. Figure 5A 1 is a schematic structural diagram of a power receiving device including a first power supply unit. Figure 5BIt is a schematic structural diagram showing another structural example of the power receiving device. Figure 6 1 is a circuit configuration diagram showing a first configuration example of a DC power supply unit of a power transmitting device and a second power supply unit of a power receiving device. Figure 7 1 is a circuit configuration diagram showing a second configuration example of the DC power supply unit and the second power supply unit. Figure 8 1 is a circuit configuration diagram showing a third configuration example of the DC power supply unit and the second power supply unit. Fig. 9 1 is a circuit configuration diagram showing a fourth configuration example of the DC power supply unit and the second power supply unit. Fig.10 This is a circuit configuration diagram showing an example of connection between a first power supply unit and a second power supply unit when the power receiving device includes a transient filter. Fig.11 1 is a circuit configuration diagram showing another configuration example of the connection between the first power supply unit and the second power supply unit. Fig.12 1 is a circuit configuration diagram showing another configuration example of the connection between the first power supply unit and the second power supply unit. Fig.13 This is a circuit configuration diagram illustrating a configuration in which the output of the first power supply unit is short-circuited using the power of the second power supply unit. Fig.14 1 is a circuit configuration diagram showing another configuration in which the output of the first power supply unit is short-circuited using the power of the second power supply unit. Fig.15 This is a circuit configuration diagram showing a configuration in which the output of the first power supply unit is short-circuited using the power of the second power supply unit. Fig.16 1 is a schematic configuration diagram showing a configuration of a power transmission device as a contactless power supply system according to a fifth embodiment. Fig.17 This is a flowchart showing an example of a power-on processing routine executed by the control device. Fig.18 This is a timing chart showing the operation of each part when the power is turned on. Fig.19 This is a flowchart showing an example of a power-on processing routine executed by the control device in the sixth embodiment. Fig. 20 This is a timing chart showing the operation of each part when the power is turned on. Fig.21 1 is a circuit configuration diagram showing a detailed configuration of a power transmission device according to a seventh embodiment. Fig. 22 1 is a circuit configuration diagram showing a circuit example in which a negative voltage is output in a DC power supply unit and a second power supply unit. Fig.23 1 is a circuit configuration diagram showing an example of a circuit for generating two voltages, positive and negative, in a DC power supply unit and a second power supply unit. DETAILED DESCRIPTION

[0011] A. First Implementation Method: (A1) Overall structure of the contactless power supply system: Figure 1 The schematic structure of the contactless power supply system 100 including the power transmission device 50 of the first embodiment is shown. As shown in the figure, the contactless power supply system 100 is composed of a plurality of power transmission devices 50 buried in the soil under the road surface RS and a power receiving device 30 installed in a moving body 20 that automatically travels on the road surface RS. The moving body 20 includes a driving wheel 21 driven by a motor (not shown) included in the load device 45, a driven wheel 22 that supports the moving body 20 together with the driving wheel 21 so that it can move on the road surface RS, a power receiving coil 31 arranged under the bottom plate of the moving body 20, and a magnet 24 similarly arranged under the bottom plate. The power receiving coil 31 receives the supply of AC power by magnetic field coupling with the power transmission coil 51 of the power transmission device 50 prepared on the road surface RS side, and converts it into DC by the first power supply unit 41 and the second power supply unit 42 provided in the power receiving device 30, and in particular, supplies power from the first power supply unit 41 to the load device 45. The power supplied by the first power supply unit 41 is the main power used at least in the moving body 20. The second power supply unit 42 outputs the power used for controlling the first power supply unit 41 in direct current. In addition to the structure buried under the road surface RS, the power transmission device 50 can also be installed on the road surface or on the wall or ceiling. In this case, the power receiving device 30 can be arranged at a predetermined position in the moving body 20 corresponding to the installation position of the power transmission device 50. For example, if the power transmission device 50 is laid on the wall, the power receiving device 30 can be arranged on the side of the moving body 20. In addition, the power receiving device 30 can be moved inside the moving body 20 in coordination with the installation position of the power transmission device 50, or a plurality of power receiving devices 30 can be prepared in advance and switched for use.

[0012] The plurality of power transmission devices 50 that supply power to the power receiving device 30 of the mobile body 20 respectively include the same structure and are arranged along the moving path of the mobile body 20. Of course, the power transmission devices 50 are not limited to the moving path of the mobile body 20, and can also be arranged two-dimensionally on the road surface RS. Each power transmission device 50 is connected to a common main power line RFP. High-frequency (e.g., 85KHz) AC power is supplied from the main power supply device 70 to the main power line RFP. In the present embodiment, each power transmission device 50 has the same structure, but, for example, power transmission coils 51 of different sizes can be alternately configured, and it does not matter if the structure is different as long as it can transmit power.

[0013] The main power supply device 70 receives a supply of low-frequency (eg, 60 Hz) alternating current from the main power supply 80 , and converts the supply into high-frequency alternating current. Figure 2 An example of the circuit structure of the main power supply device 70 is shown. The main power supply device 70 includes a noise filter 71, a PFC circuit 72, an inverter 73, and a filter 74 for AC output from the side receiving power from the main power supply 80. The PFC circuit 72 is a well-known circuit that improves the power factor by eliminating the phase difference between the input voltage and the output current generated by the filter 71, suppressing high-frequency harmonics, and making the power factor close to 1. The power supplied from the main power supply 80 is converted into the AC of the above frequency by the inverter 73, and output to the main power line RFP. The voltage output to the main power line RFP is equivalent to the first voltage.

[0014] Each power transmission device 50 operates by receiving power from the main power line RFP. Figure 1 As shown, each power transmission device 50 forms a resonance circuit by a power transmission coil 51 and a resonance capacitor 52, and an impedance circuit 55 is installed between the resonance capacitor 52 and the main power line RFP. The impedance circuit 55 is a circuit that controls the supply of high-frequency power from the main power line RFP to the resonance circuit. Equivalently, in this embodiment, it is a relay or a switch element that turns on and off the supply of high-frequency power. Each power transmission device 50 also includes a control circuit 58 that controls the impedance circuit 55, a Hall element 57 that is a magnetic sensor for detecting the presence of the moving body 20, and a DC power supply unit 60 that supplies DC power for operation to the control circuit 58. The detailed description of the power transmission device 50 will be described later, but not all power transmission devices 50 are always in operation, but only the power transmission device 50 that the moving body 20 approaches is in operation. In this embodiment, the approach of the moving body 20 is detected by detecting the magnetic force of the magnet 24 provided on the moving body 20 by the Hall element 57. When the approach of the moving body 20 is detected, the control circuit 58 changes the impedance of the impedance circuit 55, that is, if the impedance circuit 55 is a circuit structure that can be turned on and off, when the approach of the moving body 20 is detected, the impedance circuit 55 is turned on (conducted), and when the moving body 20 leaves the range where the power can be received from the power transmission coil 51, the impedance circuit 55 is turned off (cut off). The detection of the approach and departure of the moving body 20 can also be carried out by other methods, such as a structure that detects the change in mutual inductance caused by the approach of the power receiving coil 31 to the power transmission coil 51. In addition, the power transmission device 50 that is in operation is not limited to one, and two or more power transmission devices 50 that the moving body 20 approaches can also be operated.

[0015] Figure 3Schematic configurations of a power transmission device 50 and a power receiving device 30 are shown. The figure shows a state in which one of the plurality of power transmission devices 50 supplies power to the power receiving device 30 of the mobile object 20. At this time, the power transmission coil 51 of the power transmission device 50 is magnetically coupled with the power receiving coil 31 of the power receiving device 30, and an induced current (AC) flows through the power receiving coil 31. The power receiving coil 31 efficiently receives power through the power receiving side resonant circuit 33 included in the first power supply unit 41. A rectifier circuit 34 is provided at the subsequent stage of the power receiving side resonant circuit 33, and the power received by the power receiving coil 31 is converted into DC and output to the load device 45. Here, the load device 45 refers to all devices that use the power output by the first power supply unit 41, but in the case of the mobile object 20, it includes devices that use the main power used in the mobile object, such as the motor 48 for moving the mobile object 20. In addition, a battery that temporarily stores power may also be included in the load device 45.

[0016] The second power supply unit 42 is a circuit that generates a small DC power separately from the first power supply unit 41, and operates by receiving power supply from both ends of the power receiving coil 31, that is, from a position in the previous stage of the power receiving side resonance circuit 33. The DC voltage output by the second power supply unit 42 is used in the control circuit 43 and the like. The structure of the second power supply unit 42 and the specific circuit structure of the control circuit 43 will be summarized and described later.

[0017] If the above content is sorted out from the perspective of contactless power supply, on the ground side, the power supply source is the main power supply 80, which is converted into high-frequency AC power by the main power supply device 70 installed on the ground side, and then supplied to the main power line RFP. Therefore, just by laying the main power line RFP, it is possible to supply power to multiple power transmission devices 50 installed under the road surface RS. Of course, sometimes communication lines are also laid to exchange information with the power transmission device 50, but it is sufficient to use the main power line RFP as the power supply line. In the power transmission device 50, as shown in FIG. Figure 4 As shown, the movable body 20 is powered in a non-contact manner by a resonance circuit 53 composed of a resonance capacitor 52 and a power transmission coil 51, and the DC power required in the power transmission device 50 is supplied by a DC power supply unit 60. The voltage of the DC power supplied from the DC power supply unit 60 to the control circuit 58 corresponds to the second voltage.

[0018] On the other hand, the power receiving device 30 of the moving body 20 efficiently receives the induced current generated in the power receiving coil 31 magnetically coupled with the power transmitting coil 51 through the power receiving side resonance circuit 33, and supplies it to the load device 45 via the rectifier circuit 34. The first power supply unit 41 already described refers to the structure that supplies power to the load device 45 in direct current. On the other hand, the small power used in the moving body 20 is supplied by the second power supply unit 42 already described. In this way, the non-contact power supply of all the power supplied to the moving body 20 and used in the moving body 20 includes the power required by the power transmitting device 50, and is realized by the power supplied only from the main power line RFP.

[0019] (A2) Structure and operation of the DC power supply unit and the second power supply unit: The specific structures and operations of the DC power supply unit 60 in the power transmission device 50 and the second power supply unit 42 in the power reception device 30 are described. Figure 4 As shown in the example, the DC power of the second voltage is supplied to the control circuit 58 and the like included in the power transmission device 50 as the operating voltage thereof. Figure 4 In the example shown, the control circuit 58 is connected to the Hall element 57, and detects the approach of the moving body 20 by detecting the magnetic force of the magnet 24 provided on the moving body 20, thereby driving the impedance circuit 55. The power for the operation of the control circuit 58 is provided by a DC low-voltage power supply. The DC power supply unit 60 supplies a second voltage (here 5V) that is lower than the first voltage output by the main power line RFP. The DC power supply unit 60 receives power supply from the main power line RFP, but since the main power line RFP is a high-voltage and high-frequency line, it is generally known that a structure is used to step down the voltage using a transformer and perform rectification to obtain a DC low-voltage output. In this embodiment, components that are easy to enlarge, such as transformers, are not used. Instead, a DC power supply unit 60 is used. Figure 6 The circuit structure will be described below.

[0020] On the other hand, in the present embodiment, the same circuit configuration is also adopted in the second power supply unit 42 on the power receiving device 30 side. In the power receiving device 30, the voltage induced in the power receiving coil 31 is also high voltage and high frequency, and the main power used in the moving body 20 is generated by the first power supply unit 41 and supplied to the load device 45, while the DC low voltage used by the power receiving device 30 itself is supplied by the second power supply unit 42. Figure 5AOne of the circuit structures inside the mobile body 20 centered around the power receiving device 30 is illustrated. In this embodiment, the power receiving side resonance circuit 33 of the power receiving device 30 includes a resonance capacitor RC connected in series. The rectifier circuit 34 that receives the AC output of the power receiving side resonance circuit 33 is configured as a synchronous rectifier using four switching elements SW, and converts the AC into DC by exclusively turning on and off the switching elements in pairs arranged at diagonal positions in the figure in synchronization with the alternation of the voltage. A smoothing capacitor 39 is connected in parallel at the output of the rectifier circuit 34 to reduce the pulsation after rectification and supply DC power to the load device 45. This is equivalent to the operation of the first power supply unit 41. In addition, inside the load device 45, in addition to the inverter 46 or the mobile motor 48 driven by its output, a battery 47 and the like are also provided. In addition, as Figure 5B As shown, the synchronous rectifier 34A may have the diodes D1 and D2 as the upper arm and the switching elements SV1 and SV2 as the lower arm only. The structures of the upper arm and the lower arm may be reversed.

[0021] The second power supply unit 42 receives AC power from the connection point between the power receiving coil 31 and the power receiving side resonance circuit 33, converts it into a DC low voltage internally, and outputs it to the drive control circuit 44. The drive control circuit 44 performs rectification control to turn on and off the switch element SW of the rectification circuit 34 configured as the above-mentioned synchronous rectifier. The drive control circuit 44 is Figure 3 A specific example of the control circuit 43 is shown.

[0022] [1] First circuit configuration example: Hereinafter, four embodiments will be described in order with respect to the configurations of the DC power supply unit 60 of the power transmission device 50 and the second power supply unit 42 of the power reception device 30 . Figure 6 1 is a circuit diagram showing the circuit configuration of a DC power supply unit 60A and a second power supply unit 42A as a first configuration example. The circuit inputs a high-frequency, high-voltage AC voltage ACP and outputs a DC low voltage DCP. As the DC power supply unit 60A, the input is a high-frequency, high-voltage from the main power line RFP, and for the second power supply unit 42A, it is a high-frequency, high-voltage AC induced in the power receiving coil 31.

[0023] Insulating capacitors CC1 and CC2 are installed in series in the two power lines LN1 and LN2 of the circuit, respectively, and a protective diode PD1 is connected in parallel on the output sides of the insulating capacitors CC1 and CC2. A rectifying diode RD1 is connected in series in the forward direction on the output side of the insulating capacitor CC1, and a non-return diode PD2 is connected in series in the reverse direction on the output side of the insulating capacitor CC2. A Zener diode TzD and a smoothing capacitor CF are connected in parallel on the output sides of the two diodes PD1 and PD2. A circuit including at least the rectifying diode RD1 is called a rectifying unit RE, and a circuit including the Zener diode TzD and the smoothing capacitor CF is called a stabilized power supply unit SP. The rectifying unit RE sometimes includes a protective diode PD1 or a non-return diode PD2. In addition, although not specifically shown in the figure, this is Figure 7 to Figure 9 The same is true in .

[0024] The DC power supply unit 60A and the second power supply unit 42A having this circuit structure are insulated from the high-frequency, high-voltage AC voltage ACP by the insulating capacitors CC1 and CC2, and an AC voltage is generated between the two power lines LN1 and LN2 according to the change of the AC voltage ACP. Only when the power line LN1 side of the alternating voltage becomes higher than the other power line LN2, the charge accumulated in the insulating capacitors CC1 and CC2 charges the smoothing capacitor CF via the rectifying diode RD1, but the part of the alternating voltage exceeding the Zener breakdown voltage (hereinafter referred to as the Zener voltage) of the Zener diode TzD flows through the Zener diode TzD and is recovered via the non-return diode PD2, so the potential at both ends of the smoothing capacitor CF does not exceed the Zener voltage of the Zener diode TzD. Therefore, the DC low voltage DCP is maintained at the Zener voltage. When the AC voltage ACP is reversed, the power line LN1 side and the power line LN2 side maintain a potential difference of the forward direction voltage reduction amount of the protection diode PD1, so there is no effect on the smoothing capacitor CF. Although the DC power supply unit 60A and the second power supply unit 42A are connected to the high-frequency, high-voltage AC voltage ACP, the current corresponding to the charge accumulated in the insulating capacitors CC1 and CC2 does not flow through the power supply lines LN1 and LN2 during one cycle of the AC, and therefore, the amount of power output by the circuit can be easily adjusted using the capacitance of the insulating capacitors CC1 and CC2. If the amount of power handled by the DC power supply unit 60A and the second power supply unit 42A is small, that is, the capacitance can be reduced, it is possible to use capacitors with a higher withstand voltage, such as ceramic capacitors, as the insulating capacitors CC1 and CC2 instead of using more film capacitors and other capacitors with a lower withstand voltage in the power supply circuit, which can be easily achieved even when the AC voltage ACP is high.

[0025] Moreover, by using insulating capacitors CC1 and CC2, it is possible to easily separate the side that supplies the AC voltage ACP to the DC power supply unit 60A and the second power supply unit 42A, that is, the main power line RFP and the power line of the first power supply unit 41, and it is possible not to be affected by noise and the like. As a result, the possibility of malfunction of the control circuit and the like using the DC power supply unit 60A and the second power supply unit 42A can be reduced. In addition, there is no need for step-down components such as transformers that step down the voltage from a high voltage, and the circuit can be constructed to be small. Moreover, since no resistor is used in the circuit structure, the loss caused by the resistor can be eliminated and the efficiency of the circuit can be improved.

[0026] [2] Second configuration example of the circuit: Next, use Figure 7 1 and 2 are used to illustrate a second configuration example of the DC power supply unit 60 and the second power supply unit 42. FIG. 2 is a circuit diagram showing the circuit configuration of the DC power supply unit 60B and the second power supply unit 42B. The second configuration example is different from the first configuration example ( Figure 6 ) are the same except that the non-return diode PD2 is not included. In the DC power supply unit 60B and the second power supply unit 42B of the second structural example, since the non-return diode PD2 does not exist, the circuit structure can be simplified accordingly. In addition, since the forward direction reduction voltage caused by the non-return diode PD2 does not occur, the DC low voltage DCP can be increased accordingly. Other effects are the same as those of the first structural example.

[0027] [3] The third circuit configuration example: Next, use Figure 8 1 and 2 are used to illustrate a third configuration example of the DC power supply unit 60 and the second power supply unit 42. FIG. 2 is a circuit diagram showing the circuit configuration of the DC power supply unit 60C and the second power supply unit 42C. Figure 7 ) is the same except that the insulating capacitor CC2 is not included. According to the third configuration example, in addition to achieving the same effects as the second configuration example, the power supply line LN2 can be used as the ground potential of the DC low voltage DCP.

[0028] [4] Fourth circuit configuration example: Next, use Fig. 9 4. The fourth configuration example of the DC power supply unit 60 and the second power supply unit 42 is described in detail. FIG. 4 is a circuit diagram showing the circuit configuration of the DC power supply unit 60D and the second power supply unit 42D. Figure 6 and Figure 7 ) is compared with the fourth structural example, except that it includes four rectifying diodes RD1 to RD4 that constitute a diode bridge for full-wave rectification.

[0029] In this circuit structure, compared with the first to third structural examples, which convert AC to DC through half-wave rectification, the conversion efficiency can be almost doubled through full-wave rectification. Therefore, the capacity of the insulating capacitors CC1 and CC2 can be reduced. The circuit structure can be miniaturized, and high efficiency can be achieved due to the lack of loss. Other effects are the same as those of the first to third structural examples.

[0030] According to the power receiving device 30 of the first embodiment described above, it is not necessary to supply part of the power supplied to the load device 45 to the control device that controls the first power supply unit 41, which has the effect of simplifying the power structure on the mobile body 20 side. In addition, as shown in the first to fourth configuration examples, the structure of the second power supply unit 42 does not require the use of a transformer or the like for voltage reduction and insulation of the power line, and the second power supply unit 42 can be realized with a simple structure, and it is also easy to achieve miniaturization. In addition, the efficiency of the circuit that supplies power can be improved.

[0031] On the other hand, according to the power transmission system 200 including the power transmission device 50 that performs contactless power supply in the first embodiment, a DC voltage as a power supply voltage of a control circuit included in the power transmission device 50 can be generated inside the power transmission device 50. Therefore, it is not necessary to lay a power supply line for supplying a DC voltage to each power transmission device 50 other than the main power line RFP, and the laying performance and handling of the power transmission system can be improved. Moreover, as shown in the first to fourth structural examples, the structure of the DC power supply unit 60 does not require the use of a transformer for voltage reduction and insulation of the power line, and the DC power supply unit 60 can be implemented with a simple structure, and it is also easy to achieve miniaturization. In addition, the efficiency of the circuit that supplies power can be improved.

[0032] B. Second Implementation Method: Next, a description will be given of a power receiving device 30A constituting a contactless power supply system according to a second embodiment. Fig.10 : is a schematic structural diagram showing the structure of the power receiving device 30A of the second embodiment. Unlike the first embodiment, the power receiving device 30A has resonance capacitors RC1 and RC2 at both ends of the power receiving coil 31 as a power receiving side resonance circuit 33A, and has a transient filter 35 between the power receiving side resonance circuit 33A and the rectifier circuit 34 at the subsequent stage. The power receiving side resonance circuit 33A adopts a circuit structure that becomes a voltage source output. By providing the transient filter 35 at the output of the power receiving side resonance circuit 33A, it can be output as a current source. Generally speaking, when charging a battery, a current source output is used. The transient filter 35 of this embodiment is composed of four inductors L1 to L4 and a capacitor CI. Of course, in addition to the T-LCL type, a π-CLC type or a T-LCLC type transient filter can also be used.

[0033] In the second embodiment, compared with the first embodiment, the transient filter 35 is provided between the power receiving side resonance circuit 33A and the rectifier circuit 34, and the power is supplied to the second power supply unit 42 from the connection point between the power receiving coil 31 and the power receiving side resonance circuit 33 but from the connection point between the power receiving side resonance circuit 33 and the transient filter 35 at the subsequent stage. In the structure of the second embodiment, the same function and effect as the first embodiment are achieved. Therefore, in the second embodiment, even if the load device 45 side is opened and the power supply from the first power supply unit 41 is not performed, the power supply to the second power supply unit 42 continues, so various control devices that operate by receiving the power supply from the second power supply unit 42, such as the drive control circuit 44 shown in FIG. 5, remain in operation. Various circuits such as the drive control circuit 44 that operate by receiving the power supply from the second power supply unit 42 will be collectively described later.

[0034] The power supply location for supplying power to the second power supply unit 42 is not limited to Fig.10 The portion shown in FIG. 1 is a connection portion between the power receiving side resonance circuit 33 and the transient filter 35, for example, Fig.11 As shown in the power receiving device 30B of FIG. 1 , it does not matter whether the two ends of the capacitor CI in the transient filter 35 are connected. In addition, in the power receiving device, for example, Fig.12 As shown in the power receiving device 30C, the transient filter is configured to not include the reactors L1 and L2 inside. In the transient filter 35A shown in the figure, the reactors L1 and L2 are not included inside, and the leakage inductance of the power receiving coil 31 connected via the power receiving side resonance circuit 33A is used instead. In this way, the structure of the transient filter 35A can be simplified and it is also easy to achieve miniaturization.

[0035] C. Third Implementation Method: Next, a power receiving device 30D constituting the contactless power supply system as the third embodiment will be described. Fig.13 1 is a schematic structural diagram showing the structure of a power receiving device 30D according to the third embodiment. The power receiving device 30D includes the power receiving device 30D of the second embodiment. Fig.125 , and the two switching elements SL1 and SL2 of the lower arm 36 are driven by the drive control circuit 44 shown in FIG5 . The two switching elements SL1 and SL2 of the lower arm 36 are driven by the drive signal from the drive control circuit 44 and the drive signal from the cut-off control circuit 44A.

[0036] In the power receiving device 30D of the third embodiment including this circuit configuration, when a certain abnormality is detected in the first power supply unit 41 and the load device 45 serving as the load, a cutoff signal is output from the cutoff control circuit 44A to the two switch elements SL1 and SL2 of the lower arm 36, and the switch elements SL1 and SL2 are both driven to the on state. As a result, the power supply line LN1 and the power supply line LN2 of the first power supply unit 41 are substantially short-circuited, although there are on-resistances of the switch elements SL1 and SL2 on the output side of the transient filter 35A. The switch elements SL1 and SL2 turned on simultaneously by the cutoff control circuit 44A function as a protection circuit for the first power supply unit 41.

[0037] In this state, the power supply by the first power supply unit 41 is not performed, but the second power supply unit 42 receives the power supply from the connection point between the power receiving side resonance circuit 33A and the transient filter 35A, and thus can operate normally and supply the DC voltage required for the operation of the cut-off control circuit 44A to the cut-off control circuit 44A. Figures 10 to 13 In the transient filter shown in the figures, the voltage level at the input terminal or both ends of the capacitor CI is maintained at the same level when the current is normally output and when the output of the transient filter is in a short-circuited state and the protection circuit is activated. That is, when the switch elements SL1 and SL2 are simultaneously turned on and the protection circuit is activated, the input of the rectifier circuit 34A is 0 volts, so the first power supply unit 41 is maintained in a state of not outputting power. On the other hand, the voltage at both ends of the capacitor CI of the transient filter 35A is maintained in the same state as the normal state (a state where an AC voltage of a resonant frequency is applied), so the second power supply unit 42 can be connected to the rectifier circuit 34A by Figures 6 to 9 Any of the circuits shown or an equivalent circuit thereof receives the voltage and continues to supply a predetermined power to the cutoff control circuit 44A and the like.

[0038] In the power receiving device 30D of the third embodiment described above, when an abnormality occurs on the load device 45 side, by driving the switching elements SL1 and SL2 of the rectifier circuit 34 provided for rectification, the output of the first power supply unit 41 can be short-circuited, and the power supply from the first power supply unit 41 to the load device 45 can be stopped. Moreover, even in this state, the second power supply unit 42 can output a predetermined DC voltage to the outside, for example, to the drive control circuits 44A and 44B, similarly to the case where the first power supply unit 41 operates normally.

[0039] exist Fig.13 In the circuit configuration shown in FIG. 1 , in order to short-circuit the output of the transient filter 35A, the two switching elements SL1 and SL2 constituting the lower arm 36 of the rectifier circuit 34 are simultaneously turned on (conducting state). However, Fig.14 As shown in FIG. 1 , a dedicated short-circuit contact 37 is provided and driven by the cut-off control circuit 44B. Such a short-circuit contact 37 can be easily realized by a relay or a switch element. In this circuit structure, when some abnormality occurs on the load device 45 side, the output of the first power supply unit 41 can be short-circuited, which plays a role similar to Fig.13 The circuit structure shown has the same effect.

[0040] D. Fourth Implementation Method: Next, a power receiving device 30E constituting the contactless power supply system as the fourth embodiment will be described. Fig.15 1 is a schematic structural diagram showing the structure of a power receiving device 30E according to a fourth embodiment. The power receiving device 30E includes the components of the second embodiment and the third embodiment. Fig.12 The transient filter 35A shown in FIG. 1 is the same in structure, but is different in that it includes a cutoff control circuit 44C that is operated by receiving the supply of DC power from the second power supply unit 42. Fig.15 The circuit configuration shown further includes a control circuit 49 for driving four switching elements of the rectifier circuit 34 to realize synchronous rectification. In this example, the control circuit 49 operates with a power supply voltage Vcc derived from a DC voltage supplied from the first power supply unit 41 to the load device 45 .

[0041] Two of the four drive signals output by the control circuit 49 are directly output to the gates of the switch elements SU1 and SU2, but the remaining two drive signals are input to one input terminal of the 2-input OR gates ORG1 and ORG2, and are output to the gates of the switch elements SL1 and SL2 via the OR gates ORG1 and ORG2. The 2-input OR gates ORG1 and ORG2 operate together with the cut-off control circuit 44C using the DC voltage from the second power supply unit 42 as a power supply. The output signal from the cut-off control circuit 44C is input to the other input terminal of the 2-input OR gates ORG1 and ORG2. The cut-off control circuit 44C has a built-in node gate NOT that takes the power supply voltage Vcc as an input, and the output of the node gate NOT becomes an output signal output to the 2-input OR gates ORG1 and ORG2. Therefore, when the power supply voltage Vcc derived from the load device 45 collapses and becomes 0 volts, the output signal of the cutoff control circuit 44C having the built-in node gate NOT becomes high level, and even if the output signal from the control circuit 49 becomes low level due to the collapse of the power supply voltage Vcc, the outputs of the two-input OR gates ORG1 and ORG2 become high level. As a result, the switch elements SL1 and SL2 become conductive, and the output voltage of the first power supply unit 41 can be cut off as in the third embodiment.

[0042] The power receiving device 30E of the fourth embodiment can disconnect the output of the first power supply unit 41 in the rectifier circuit 34 by operating the cut-off control circuit 44C and the 2-input OR gates ORG1 and ORG2 that supply power from the second power supply unit 42 when the power supplied to the control circuit 49 that drives the switching element of the rectifier circuit 34 and performs synchronous rectification. In order to realize such an operation, the power supplied by the second power supply unit 42 is only slightly small, and the output of the first power supply unit 41 in the rectifier circuit 34 is disconnected by operating the cut-off control circuit 44C and the 2-input OR gates ORG1 and ORG2 that supply power from ... only disconnected by operating the cut-off control circuit 44C and the 2-input OR gates ORG1 and ORG2 that supply power from the second power supply unit 42 is only disconnected by operating the cut-off control circuit 44C and the 2-input OR gates ORG1 and ORG2 that supply Figures 6 to 9 The simple structure of the second power supply unit 42 shown in the above-mentioned figures can realize a practical circuit structure.

[0043] E. Fifth Implementation Method: Next, a power receiving device 150 constituting the contactless power supply system as the fifth embodiment will be described. Fig.16As shown, the power transmission device 150 operates by receiving power from the main power supply device 70, similarly to the power transmission device 50 of the first embodiment, and includes a resonance circuit 53 composed of a power transmission coil 51 and a resonance capacitor 52, and an impedance circuit 55. In addition, the power transmission device 150 includes a drive circuit 156 that drives the impedance circuit 55, a current sensor 157 that detects the current flowing through the resonance circuit 53, and a control unit 158 ​​that controls the impedance circuit 55. The control unit 158 ​​uses the current value detected by the current sensor 157 to control the impedance circuit 55 via the drive circuit 156 and controls the current Ir flowing through the resonance circuit 53. In addition, the drive circuit 156 and the current sensor 157 are respectively provided with circuits for detecting their own operating voltages V1 and V2, and the drive circuit 156 and the current sensor 157 output the values ​​of the detected operating voltages V1 and V2 to the control unit 158. The operating voltages V1 and V2 are processed in the sixth embodiment described later, and may not be detected in the fifth embodiment.

[0044] The power supply of each part of the power transmission device 150 includes the following structure. In this embodiment, since the operating voltages of the drive circuit 156, the current sensor 157, and the control unit 158 ​​are different, three DC power supply units 160, 161, and 162 are provided. The structure of each DC power supply unit 160-162 may be any of the circuit structures shown as the structural examples 1-3 of the DC power supply unit 60 in the first embodiment. The DC output of the DC power supply units 160-162 is the second voltage Vcc, which is the operating voltage of the control unit 158. On the other hand, the output of the DC power supply unit 161 is output to the drive voltage V1 output unit 171, and is converted into the drive voltage V1 suitable for the operation of the drive circuit 156. Similarly, the output of the DC power supply unit 162 is output to the drive voltage V2 output unit 172, and is converted into the drive voltage V2 suitable for the operation of the current sensor 157. Such a drive voltage V1 output unit 171 and a drive voltage V2 output unit 172 can be implemented as a well-known DC / DC converter. In addition, in order to ensure the current capacity required for the operation of each part, in this embodiment, three DC power supply units 160 to 162 that output the same second voltage Vcc are prepared, but if the current capacity can be ensured, power can also be supplied from one DC power supply unit 160. In addition, it does not matter if each DC power supply unit 160 to 162 is configured to output the voltage required for the operation of the control unit 158, the drive circuit 156, and the current sensor 157 as the supply destination of power. In this case, the drive voltage V1 output unit 171 and the drive voltage V2 output unit 172 are not required.

[0045] In the power transmission device 150 of the present embodiment, when the power receiving coil 31 of the power receiving device 30 is not approaching, the impedance of the impedance circuit 55 is high, and only a small current (standby current) flows in the resonance circuit 53. The current value Ir is detected by the current sensor 157 and output to the control unit 158. In the stable state where the second voltage Vcc supplied from each DC power supply unit 160 is established, the control unit 158 ​​monitors the current value Ir and detects the approach of the power receiving coil 31. When the power receiving coil 31 approaches the power transmission coil 51, the current flowing through the resonance circuit 53 increases due to magnetic field coupling. When the current value Ir flowing through the resonance circuit 53 exceeds a predetermined threshold, the control unit 158 ​​determines that the power receiving coil 31 is approaching, outputs a drive signal via the drive circuit 156, and switches the impedance of the impedance circuit 55 to a lower value. As a result, the current value Ir flowing through the resonance circuit 53 increases, and power is supplied to the power receiving device 30 through magnetic field coupling. Conversely, when the power receiving coil 31 moves away from the power transmitting coil 51 , the current value I r decreases. Therefore, the control unit 158 ​​compares it with a predetermined threshold value, and switches the impedance circuit 55 to a high impedance state if the current value I r is less than the threshold value.

[0046] The impedance control of switching the impedance of the impedance circuit 55 and the power control of turning on and off the supply of AC power to the power transmission coil 51 described above by the control unit 158 ​​are based on the premise that the control unit 158 ​​operates normally. The control unit 158 ​​can also be implemented as a discrete circuit, but in this embodiment, it is configured as a microcomputer composed of a CPU that performs arithmetic logic operations and a memory that stores a program that causes the CPU to perform a predetermined control operation. In the case of such a control unit 158 ​​that performs arithmetic logic operations such as a microcomputer, it is a prerequisite for ensuring normal operation that the second voltage Vcc for operation falls within a predetermined rated range. The second voltage Vcc is generally prone to become unstable within a predetermined time immediately after the power supply from the main power supply device 70 to the power transmission device 150 is started, and the result of the arithmetic logic operation may not be guaranteed depending on the situation.

[0047] As described in the first embodiment, when a plurality of power transmission devices are provided, the AC power from the main power supply device 70 is not supplied to all of the power transmission devices, but the AC power of the main power supply device 70 is supplied only to the power transmission device 150 that may be related to the power supply. In this case, each DC power supply unit 160 to 162 outputs the power supply voltage Vcc after receiving the supply of the AC power from the main power supply device 70. Therefore, in order to stably operate the control unit 158 ​​using the second voltage Vcc, the following processing is performed in the present embodiment.

[0048] The control unit 158 ​​configured as a microcomputer executes Fig.17 The power-on processing shown in the figure. “Power-on” refers to the time when the second voltage Vcc applied to the power terminal of the control unit 158 ​​is greater than the first threshold value Von, which is the voltage at which the microcomputer constituting the control unit 158 ​​starts to operate. Fig.18 100 shows a timing chart when the power is turned on. As shown in the figure, when the main power supply device 70 starts and starts supplying AC power to the main power line RFP at time t0, the second voltage Vcc output by the DC power supply unit 160 gradually increases and finally reaches the rated voltage Vcc. When the second voltage Vcc rises and exceeds the first threshold value Von at time t1, the microcomputer constituting the control unit 158 ​​starts the arithmetic logic operation circuit inside the control circuit (step S101). This process is equivalent to the initialization process in the microcomputer.

[0049] Next, the process of turning on the output shield is performed (step S111). Output shielding refers to the process of shielding the output signal output from the output terminal of the control unit 158 ​​and setting it to be disconnected. Regardless of whether the result of the arithmetic logic operation of the microcomputer is a value of 1 (logical high) or a value of 0 (logical low), the output of the output terminal set to be shielded is disconnected. Here, all output terminals are set to be shielded. As a result, all output terminals of the control unit 158 ​​are disconnected, and the impedance circuit 55 is also maintained in a low impedance state as a default state.

[0050] After that, the microcomputer starts the built-in timer counter (step S121). Since the timer counter counts the counter value TCC at a predetermined time interval, Fig.18 As shown, its value increases with a specified gradient. The microcomputer repeatedly determines the magnitude relationship between the value TCC of the timer counter and the threshold value Thc corresponding to the predetermined time until the counter value TCC is greater than the threshold value Thc (step S131). Fig.18 As shown at time t2 in FIG. 1 , when the count value TCC is greater than the threshold value Thc, the timer counter is reset to a value of 0 (step S141), and the output mask set to on is switched to off (step S151). As a result, the output of the control unit 158 ​​is masked during the period from time t1 to time t2. After the above processing, the control unit 158 ​​exits the "next" and ends the processing routine. The microcomputer of the control unit 158 ​​performs normal control, such as the impedance control of reducing the impedance of the impedance circuit 55 and increasing the current value Ir of the resonance circuit 53 after determining that the power receiving coil 31 of the power receiving device 30 is approaching.

[0051] In this embodiment, even if the second voltage Vcc supplied to the control unit 158 ​​exceeds the first threshold value Von at which the microcomputer constituting the control unit 158 ​​can start its operation, the output of the control unit 158 ​​is shielded for a predetermined time. Therefore, during this period, the power transmission device 150 does not output to various control objects including the impedance circuit 55, and the control unit 158 ​​can output to the control object after the second voltage Vcc stabilizes. As a result, it is possible to suppress the occurrence of malfunctions caused by the instability of the second voltage Vcc when the power is turned on.

[0052] In this embodiment, the output from the control unit 158 ​​is masked within a specified time after the second voltage Vcc exceeds the first threshold value Von, but the microcomputer in the control unit 158 ​​may be configured to implement a time counter through software and only monitor the passage of a specified time, or repeatedly execute commands that are not actually processing, such as NOP. Alternatively, a circuit that repeatedly generates NMIs for the microcomputer may be provided in the control unit 158, and an interrupt that cannot be masked may be applied within a specified period, thereby repeatedly performing processing other than normal control, such as initialization processing, on the microcomputer.

[0053] F. Sixth Implementation Method: Next, the sixth embodiment will be described. The hardware configuration of the sixth embodiment is the same as that of the fifth embodiment, but the content of the processing when the power is turned on is different. In the sixth embodiment, the control unit 158 ​​of the power transmission device 150 executes Fig.19 When the main power supply device 70 starts to supply AC power to the main power line RFP at the first voltage, the second voltage Vcc rises and becomes higher than the first threshold value Von at time t1. At this time, the microcomputer constituting the control unit 158 ​​starts the arithmetic logic operation circuit inside the control circuit (step S201).

[0054] Next, similarly to the fifth embodiment, the process of turning on the output shield is performed (step S211). As a result, all output terminals of the control unit 158 ​​are disconnected, and the impedance circuit 55 is also maintained in a low impedance state as a default state. Afterwards, the microcomputer performs a process of acquiring a driving voltage V1 as the power supply voltage of the driving circuit 156 and a driving voltage V2 as the power supply voltage of the current sensor 157 (step S221). It is judged whether the acquired driving voltage V1 is greater than a predetermined second threshold value Va, and whether the driving voltage V2 is greater than a predetermined third threshold value Vb (step S231). The second threshold value Va and the third threshold value Vb used in the judgment of the driving voltage V1 and the driving voltage V2 may be the same or different.

[0055] V1>Va and V2>Vb…(Condition 1) Repeat the process of step S231 until the above condition 1 is satisfied. When it is determined that the above condition 1 is satisfied, the process of turning off the output shield is executed (step S241). Fig. 20 As shown. As shown in the figure, when the second voltage Vcc as the power supply voltage of the control unit 158 ​​is higher than the first threshold value Von, the output shield is turned on, and this state is maintained until the above-mentioned condition 1 is satisfied. When the driving voltages V1 and V2 are respectively greater than the predetermined second threshold value Va and the third threshold value Vb, the output shield is turned off, and the output of the control unit 158 ​​begins to become valid. In this way, in the sixth embodiment, although the timer counter of the fifth embodiment is not used, the same effect as the fifth embodiment is achieved. In addition, in the sixth embodiment, the driving voltage V1 as the power supply voltage of the driving circuit 156 and the driving voltage V2 as the power supply voltage of the current sensor 157 are directly detected, and after confirming that they become the power supply voltages at which each circuit and sensor can operate normally, the output shield is turned off, so that unstable operation when the power is turned on can be more reliably avoided. In addition, in order to invalidate the output of the control unit 158, as in the fifth embodiment, a method other than turning on the output shield can also be used.

[0056] G. Seventh Implementation Method: Fig.21 The structure of the power transmission device 250 of the seventh embodiment is shown. As shown in the figure, the power transmission device 250 operates under the AC voltage ACP which is the first voltage applied to the two power lines NL1 and NL2. The power transmission device 250 includes: a first capacitor Cs and a second capacitor Cr which constitute a resonance circuit 253 together with a power transmission coil 251, a switching element SW1 which connects or disconnects the connection of the second capacitor Cr, and a disconnection unit 255 which disconnects the application of the AC voltage ACP to the resonance circuit 253. When the switching element SW1 becomes turned on (connected state), the second capacitor Cr is connected in parallel with the first capacitor Cs. The switching element SW1 performs impedance control. In addition, the disconnection unit 255 performs protection control.

[0057] In the resonance circuit 253, two capacitors are connected in series with the power transmission coil 251 to form a series resonance (SS) circuit. The frequency of the AC voltage ACP is 85kHz in this embodiment, and the capacitances of the first capacitor Cs and the second capacitor Cr are set so that when the switch element SW1 is turned on, that is, the two capacitors are connected in parallel and the capacitance relative to the inductance of the power transmission coil 251 becomes the sum of the capacitances of the two capacitors, the resonance frequency of the resonance circuit 253 coincides with the frequency of the AC voltage ACP. On the other hand, when the switch element SW1 is in the off state, the resonance frequency of the resonance circuit 253 composed of the power transmission coil 251 and the first capacitor Cs deviates from the frequency of the AC voltage applied by the AC voltage ACP. Since the two power lines NL1 and NL2 are applied with AC, it is impossible to call one of the lines the ground line GND, but for convenience, in the following description, the power line NL2 is sometimes called the ground line GND.

[0058] The power transmission device 250 includes a gate circuit 267 that drives the switch element SW1 and the cut-off unit 255. The gate circuit 267 is connected to the output ports P1 and P2 of the control unit 265, and drives the switch element SW1 and the cut-off unit 255 when the ports P1 and P2 become high levels. The cut-off unit 255 determines whether to apply the AC voltage ACP to the resonant circuit 253. As long as the cut-off unit 255 is a component that can be electrically connected and disconnected, such as a relay contact, a fuse, or a semiconductor switch element, it can be a component that operates reversibly or an irreversibly. In the present embodiment, the cut-off unit 255 is a method of reversibly operating using a semiconductor switch, but it can also be configured using a component that is irreversibly disconnected by a signal from the outside. For example, it can also be a thermal fuse including a heater, and the heater is heated by a signal from the gate circuit 267 to melt the fuse. Alternatively, it can also be configured to be like a circuit breaker, and once disconnected, it will not return to the conductive state unless it is manually or restored by the control unit 265.

[0059] In addition, the power transmission device 250 is also provided with an abnormality detector 261 and a proximity sensor 263. The abnormality detector 261 detects an abnormality of the power transmission device 250, and may be, for example, a current sensor that detects overheating, overcurrent, etc. of the power transmission device 250. In the case of a sensor that detects overheating of the power transmission coil 251, the abnormality detector 261 is provided to be thermally coupled with the detection object. Alternatively, it may be a device that processes with the control unit 265 or the control circuit 43 on the power receiving device 30 side and detects an abnormality as the contactless power supply system 100. For example, a situation in which the proximity sensor 263 mistakenly detects the approach of the power receiving device 30 may be detected as an abnormality. In this case, the power transmission device 250 may also have a communication unit that communicates with the power receiving device 30.

[0060] In the power transmission device 250, the DC power of the second voltage Vcc output by the DC power supply unit 260 is supplied not only to the control unit 265, but also to the abnormality detector 261 and the proximity sensor 263. In addition, a voltage condition detection unit 262 is connected to the power line of the second voltage Vcc to determine whether the second voltage Vcc is established. The determination method can adopt the same method as the fifth embodiment and the sixth embodiment.

[0061] In the seventh embodiment, before the voltage condition detection unit 262 determines that the second voltage Vcc is established, it outputs a signal to the reset terminal RST (or the operation prohibition terminal I NH) of the control unit 265 to stop the operation of the control unit 265. At the same time or separately, the voltage condition detection unit 262 outputs a signal to the operation prohibition terminal I NH of the gate circuit 267, and makes the output of the gate circuit 267 prohibited or in a high impedance state.

[0062] In the power transmission device 250 of the seventh embodiment described above, when the power is turned on, no signal is output to the cut-off section 255 or the switch element SW1 until the second voltage Vcc of the DC power source supplied to the control section 265 etc. is established. Therefore, the control section 265 can suppress the occurrence of a situation in which an erroneous signal is output to the cut-off section 255 or the switch element SW1 due to unstable power supply voltage of the control section 265 itself or the abnormality detector 261, the proximity sensor 263, etc., thereby inducing malfunction in the protection control or the impedance control.

[0063] H. Other structural examples of DC power supply and second power supply: Various embodiments and configuration examples have been described above, but the DC power supply unit 60, 160, 260 and the second power supply unit 42, 42A-42D are not limited to positive voltages, and may also be a structure that generates negative voltages and supplies negative voltage power to necessary circuits. Fig. 22 As shown, in Figure 6 The structure example 1 shown, Figure 7 The structure example 2 shown, Figure 8 In the circuit structure corresponding to the structure example 3 shown in the figure, it is easy to output a negative voltage. Fig. 22 In each circuit structure of FIG. 1 , the directions of diodes PD1, PD2, RD1, Zener diode TzD, etc. are opposite to those of the corresponding structure examples 1 to 3. For other points, the structure is the same as that of the corresponding figure. Fig. 22 In the circuit configurations of the upper and middle columns of the figure, the GND potentials of the two lines of the output DC voltage DCP become floating. In addition, in the circuit configuration of the lower column of the figure, the GND potentials of the two lines of the output DC voltage DCP are common to either the P or N line of the AC voltage ACP.

[0064] If necessary, the DC power supply unit 60, 160, 260 and the second power supply unit 42, 42A-42D may also be a circuit structure that outputs positive voltage and negative voltage at the same time. Fig.23 The upper and lower columns of exemplify such a circuit structure. Fig.23 The upper column is Figure 8 The circuit structure of the output positive voltage is shown and Fig. 22 The circuit structure of the output negative voltage shown in the lower column of is combined. In this circuit structure, the GND of the direct current voltage DCP and either the P or N line of the alternating current voltage ACP are common.

[0065] Fig.23 The lower column shows another example of a circuit structure that outputs both positive and negative voltages. Figure 7 The circuit structure of the output positive voltage is shown and Fig. 22 The circuit structure of the output negative voltage shown in the middle column of is combined. In this circuit structure, the GND potential of the DC voltage DCP becomes floating. In this circuit structure, both positive and negative voltages can be output at the same time, and the capacitor CC2 can be used at the same time, so the circuit structure components can be reduced.

[0066] I. Other implementations: (1) One of the other embodiments is a method as a contactless power transmission system. The contactless power transmission system includes: a plurality of power transmission devices, the plurality of power transmission devices including a power transmission coil, the power transmission coil being arranged within the movable range of the mobile body and transmitting power to the power receiving device of the mobile body in a contactless manner; a main power line, the main power line supplying AC power of a first voltage for the power transmission to the plurality of power transmission devices; and a DC power supply unit, the DC power supply unit receiving the supply of AC power from the main power line and outputting power of a second voltage which is a voltage lower than the first voltage and is used for control within the power transmission device. According to the contactless power transmission system, in addition to the main power line supplying AC power of the first voltage, there is no need to lay a line for a second voltage which is lower than the first voltage, so that the structure of the power transmission system can be simplified.

[0067] Multiple power transmission devices can be arranged along the moving path of the moving body, or they can be arranged in a manner that fills a two-dimensional plane. The moving body that receives power via the power receiving device can be a four-wheeled car, a two-wheeled vehicle, or a large bus or truck, or an unmanned vehicle such as an automatic guided vehicle. Of course, it can also be a moving body that moves without using wheels, such as a hovercraft or a magnetically suspended linear electric vehicle. The power transmission coil that uses magnetic coupling to transmit alternating current in a non-contact manner can be housed inside the housing of the power transmission device, or it can be exposed to the outside. The power transmission coil can be configured or buried in the floor or road surface on which the moving body moves, but it can also be configured on a wall or ceiling. In the case where the moving body is a straddle-type monorail, power can also be received and supplied through magnetic coupling within the track that restricts the movement of the moving body. The power transmission coil can be configured in a manner that is close to the power receiving coil, or it can be supplied with power by sandwiching a relay coil between the power receiving coil. In this case, in the case where the moving body includes wheels such as tires, a structure in which the relay coil is set in the tire or its wheel hub can also be adopted. In the above embodiment, the plurality of power transmission devices 50 are described as switching and performing power supply operation according to the approach of the moving object 20 , but the power transmission device may be a power transmission device that always performs power supply operation.

[0068] In the above-mentioned embodiments, the control circuit 58 is described as a circuit that uses the Hall element 57 to detect the position and approach of the moving body 20, but it can also be a circuit that receives the DC voltage from the DC power supply unit 260 and operates, and other circuit structures can be used. For example, it can be a circuit that uses a detection coil instead of the Hall element 57 to detect the position or approach of the moving body 20, a circuit that detects the position or approach of the moving body 20 based on the current flowing through the power transmission coil 51 or the voltage across the power transmission coil 51, or a circuit that detects the position or approach of the moving body 20 based on the current or voltage of the resonance capacitor 52. In addition, the object controlled by the control circuit 58 is not limited to the impedance circuit 55, and any circuit can be used as long as it is a circuit required by each power transmission device 50 and uses a DC voltage. For example, if it is a circuit that makes the resonant frequency of the resonant circuit variable, a circuit structure using a variable capacitor, a capacitor series-parallel switching circuit using a capacitor and a switching element, a coil winding number switching circuit using a switching element, etc. can be adopted. In the above-mentioned embodiments, the circuit structure is configured to turn on or off the supply of high-frequency power. Such a circuit can be formed using a relay, a switching element, or the like.

[0069] (2) In such a structure, the above-mentioned multiple power transmission devices may be connected in parallel with the above-mentioned main power line, and the above-mentioned DC power supply unit may be arranged corresponding to the above-mentioned power transmission device, or may be arranged respectively in the above-mentioned power transmission device. In this way, the degree of freedom of arrangement of the multiple power transmission devices can be improved. The DC power supply unit may be arranged in the power transmission device, or may be arranged close to the outside thereof corresponding to the power transmission device. In addition, one DC power supply unit may be arranged corresponding to multiple power transmission devices. In this case, wiring from the DC power supply unit to the power transmission device is required, but compared with laying power lines for supplying electric power of the second voltage to all power transmission devices, the wiring distance and installation time can be reduced.

[0070] (3) In the structures of (1) and (2) above, the DC power line as the power line of the DC power supply unit may be connected to the main power line via an insulating capacitor. In this way, even if the AC voltage of the main power line is separated from the second voltage output by the DC power supply unit, the DC voltage output by the second power supply unit can be obtained without using large components such as a step-down transformer. In addition, if insulating capacitors are installed in all connections with the main power line, the DC power supply unit can be easily insulated from the main power line, and noise resistance performance can be improved.

[0071] (4) In the above structures (1) to (3), the main power line may be a single-phase AC line, and the insulating capacitor may be provided on at least one side of the power line of the DC power supply unit. In this way, the conversion from the single-phase AC line to the DC can be realized with a simple structure.

[0072] (5) In the above structures (1) to (4), the DC power supply unit may include, in order from the upstream side of the power supply, a rectifier unit using a diode and a stabilized power supply unit consisting of a Zener diode connected in parallel to the DC power supply line and a smoothing capacitor. In this way, a stable DC voltage can be obtained with a simple structure. The stabilized power supply unit is not limited to a structure using a Zener diode, and may also use a circuit structure using a transistor, a three-terminal regulator that adjusts to a specified voltage output, or the like.

[0073] (6) In the configurations of (1) to (5) above, the rectifying section may be a half-wave rectifier or a full-wave rectifier. In this way, if the power is sufficient, the number of rectifying diodes can be reduced, which helps save resources.

[0074] (7) In the configurations of (1) to (6), the rectifying unit may include a diode mounted on one of the DC power lines and a non-return diode mounted on the other of the power lines. This can prevent reverse flow.

[0075] (8) In the configurations of (1) to (7) above, as control in the power transmission device, specifically Figure 1 The control performed by the control circuit 58 shown may also include at least one of the following controls: [1] power control for turning on and off the supply of the AC power of the first voltage to the power transmission coil; [2] Impedance control for making the resonance state of the resonance circuit using the power transmission coil variable; [3] performing detection control for detecting the power receiving coil on the moving body side; [4] driving and controlling the switching elements present in the above-mentioned power transmission device; [5] Protection control for activating a protection circuit provided in the above-mentioned power transmission device. By providing the DC power supply unit in this way, various controls can be implemented. As controls for making the resonance state of the resonance circuit variable, there are various controls such as control for changing the resonance frequency and control for changing the sharpness (Q value) of the resonance.

[0076] (9) In such a structure, a control unit may be included, which operates and performs the control according to the second voltage output from the DC power supply unit, and when the DC power supply unit receives the supply of AC power from the main power line and starts to output the second voltage, the control unit reserves the execution of at least a part of the control until a predetermined operation condition is satisfied. Reserved execution of at least a part of the control includes not performing any control at all before the operation condition is satisfied, not performing at least control related to power transmission, not performing at least control related to safety, and performing the control at the highest safety side even when the control is performed. Performing the control at the higher safety side means, for example, controlling the resonance state of the resonant circuit to a side lower than the peak value in the case of impedance control. If the control unit adopts a structure in which an arithmetic logic operation circuit such as a microcomputer is operated by a program, various countermeasures such as stopping the execution of the program and prohibiting or inhibiting the output of the execution result can be taken. In the case where the control unit adopts a discrete circuit structure for performing timing control such as a ladder diagram or a PLC, it is sufficient to stop a part of the timing before the second voltage is established.

[0077] (10) In such a structure, the above-mentioned action condition may also include any one of the following conditions: <1> A predetermined period of time has elapsed since the second voltage became equal to or higher than a first threshold value predetermined as a voltage at which the control unit can operate; <2> When the control unit performs at least one of the power control and the impedance control, a first voltage condition and a second voltage condition are simultaneously satisfied, the first voltage condition being that the second voltage becomes equal to or higher than a first threshold value predetermined as a voltage at which the control unit can operate, and the second voltage condition being that the second voltage becomes equal to or higher than a second threshold value predetermined as a voltage at which a sensor required for the power control and the impedance control can operate, or a predetermined period of time has elapsed since the second voltage became equal to or higher than the first threshold value and the second threshold value; <3> When the control unit performs at least one of the detection control and the protection control, the second voltage becomes greater than a first threshold value predetermined as a voltage at which the control unit can operate, and becomes greater than a third threshold value predetermined as a voltage at which the detection unit required for the detection control and the protection control can operate, or a specified period of time has passed since the second voltage became greater than the first threshold value and the third threshold value. In this way, the reliability of each control can be improved. In addition to the above, as the operating condition, a structure can be adopted in which a permission signal is received from a diagnostic device provided in the entire non-contact power supply system and communicates with multiple power transmission devices respectively, and the power transmission devices communicate with each other, confirm the operating conditions with each other, and then permit.

[0078] (11) In the second item, the control unit may include an arithmetic logic circuit that performs the control by executing a program, and the retention of execution of at least a part of the control may be achieved by any one of the following means: (A) stopping the execution of the arithmetic logic operation circuit; (B) prohibition of output based on the operation result of the arithmetic logic operation circuit; (C) A gate circuit which inputs the output signal of the arithmetic logic operation circuit and does not output until the enable signal is input.

[0079] (12) One of the other embodiments is a method of a contactless power supply system. The contactless power supply system may also include: a power receiving device, the power receiving device having a power receiving coil disposed inside a moving body; a plurality of power transmitting devices, the plurality of power transmitting devices including a power transmitting coil disposed within a movable range of the moving body and magnetically coupled with the power receiving coil of the power receiving device of the moving body to transmit power in a contactless manner; a main power line, the main power line supplying AC power of a first voltage for the power transmission to the plurality of power transmitting devices; and a DC power supply unit, the DC power supply unit receiving the supply of AC power from the main power line and outputting power of a second voltage for control in the power transmitting device which is a voltage lower than the first voltage. In this way, contactless power supply can be provided to the power receiving device, and the supply of the second voltage for control on the power receiving device side can be simplified. As a result, the structure of the contactless power supply system can be simplified, and the man-hours for laying the power transmitting side can be reduced.

[0080] (13) In such a structure, the plurality of power transmission devices may be connected in parallel to the main power line, and the DC power supply unit may be provided corresponding to the power transmission device or provided in each of the power transmission devices. In this way, the degree of freedom in arranging the plurality of power transmission devices may be increased. The DC power supply unit may be provided in the power transmission device or may be provided close to the outside of the power transmission device. In addition, one DC power supply unit may be provided corresponding to the plurality of power transmission devices.

[0081] (12) One of the other embodiments is a method as a contactless power supply method. The contactless power supply method may also supply AC power of a first voltage to a plurality of power transmission devices disposed within the movable range of a mobile body via a main power line, and output power of a second voltage, which is an operating voltage of a control unit in the power transmission device and is a voltage lower than the first voltage, through a DC power supply unit that receives the supply of AC power from the main power line. Under the control of the control unit, at least one of the plurality of power transmission devices uses the AC power of the first voltage to supply high-frequency AC power to a power transmission coil disposed in the power transmission device, and transmits power to a power receiving coil of a power receiving device of the mobile body via the power transmission coil in a contactless manner. In this way, in addition to the main power line that supplies AC power of the first voltage, there is no need to lay a line for a second voltage lower than the first voltage in coordination with the power transmission device, and the structure of the contactless power supply system can be simplified.

[0082] 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.

[0083] The control unit and method described in the present disclosure may also be implemented by a special-purpose computer, which is provided by forming a processor and a memory, and the processor is programmed to perform one or more functions embodied by a computer program. Alternatively, the control unit and method described in the present disclosure may be implemented by a special-purpose computer, which is provided by forming a processor composed of one or more special-purpose hardware logic circuits. Alternatively, the control unit and the method described in the present disclosure may be implemented by one or more special-purpose computers, which are composed of a processor and a memory programmed to perform one or more functions and a processor composed of one or more hardware logic circuits. In addition, the computer program may also be stored in a computer-readable non-migrating tangible recording medium as an instruction executed by a computer. "Computer-readable non-migrating tangible recording medium" is not limited to portable recording media such as floppy disks or CD-ROMs, but also includes various internal storage devices in computers such as RAM or ROM, and external storage devices such as hard disks fixed to computers. That is, "computer-readable non-migrating tangible recording medium" has a broad meaning including any recording medium that can fix data packets rather than temporary.

Claims

1. A contactless power transmission system, the contactless power transmission system (200) comprising: A plurality of power transmission devices (50), each of which includes a power transmission coil (51), the power transmission coil being arranged within a moving range of a moving body (20) and transmitting power to a power receiving device (30) of the moving body in a non-contact manner; a main power supply line (RFP) for supplying AC power of a first voltage for the power transmission to the plurality of power transmission devices; as well as A DC power supply unit (60) receives AC power from the main power supply line and outputs power of a second voltage which is lower than the first voltage and is used for control in the power transmission device.

2. The contactless power transmission system according to claim 1, wherein: The plurality of power transmission devices are connected in parallel to the main power line, The DC power supply unit is provided corresponding to the power transmission device, or is provided in the power transmission device.

3. The contactless power transmission system according to claim 1, wherein: A DC power supply line (LN1, LN2) serving as a power supply line of the DC power supply unit is connected to the main power supply line via an insulating capacitor (CC1, CC2).

4. The contactless power transmission system according to claim 3, characterized in that: The main power supply line is a single-phase AC line, and the insulating capacitor is provided on at least one side of the power supply line of the DC power supply unit.

5. The contactless power transmission system according to claim 3, wherein: The DC power supply unit includes, in order from the upstream side of the power supply, a rectifier unit (RE) using a diode (RD1); and a stabilized power supply unit (SP) having a Zener diode (TzD) and a smoothing capacitor (CF) connected in parallel to the DC power supply line.

6. The contactless power transmission system according to claim 5, characterized in that: The rectifier unit is configured as a half-wave rectifier or a full-wave rectifier.

7. The contactless power transmission system according to claim 5, wherein: The rectifying unit includes a rectifying diode (PD1) attached to one of the DC power lines and a non-return diode (PD2) attached to the other of the power lines.

8. The contactless power transmission system according to any one of claims 1 to 7, characterized in that: The control in the power transmission device includes at least one of the following controls: [1] power control for turning on and off the supply of the AC power of the first voltage to the power transmission coil; [2] impedance control that enables the resonance state of the resonance circuit using the power transmission coil to be changed; [3] performing detection control of the power receiving coil (31) on the moving body side; [4] driving control of a switch element (SW1) present in the power transmission device; [5] Protection control for activating a protection circuit (255) provided in the power transmission device.

9. The contactless power transmission system according to claim 8, characterized in that: comprising a control unit (158, 265) which operates and performs the control according to the second voltage outputted from the DC power supply unit, When the DC power supply receives the supply of AC power from the main power line and starts outputting the second voltage, the control unit suspends execution of at least a part of the control until a predetermined operating condition is satisfied.

10. The contactless power transmission system according to claim 9, wherein: The action condition includes any one of the following conditions: <1> A predetermined period of time has elapsed since the second voltage became equal to or higher than a first threshold value predetermined as a voltage at which the control unit can operate; <2> When the control unit performs at least one of the power control and the impedance control, a first voltage condition and a second voltage condition are both satisfied, the first voltage condition being that the second voltage becomes equal to or greater than a first threshold value predetermined as a voltage at which the control unit can operate, and the second voltage condition being that the second voltage becomes equal to or greater than a second threshold value predetermined as a voltage at which a sensor (157) required for the power control and the impedance control can operate, or a predetermined period of time has elapsed since the second voltage became equal to or greater than the first threshold value and the second threshold value; <3> When the control unit performs at least one of the detection control and the protection control, the second voltage becomes greater than a first threshold value predetermined as a voltage at which the control unit can operate, and becomes greater than a third threshold value predetermined as a voltage at which the detection unit (222, 261) required for the detection control and the protection control can operate, or a specified period of time has passed since the second voltage became greater than the first threshold value and the third threshold value.

11. The contactless power transmission system according to claim 9, wherein: The control unit includes an arithmetic logic operation circuit that performs the control by executing a program, and the retention of execution of at least a part of the control is achieved by any one of the following means: (A) stopping the execution of the arithmetic logic operation circuit; (B) prohibition of output based on the operation result of the arithmetic logic operation circuit; (C) A gate circuit (267) which inputs the output signal of the arithmetic logic operation circuit and does not output until the enable signal is input.

12. A contactless power supply system, the contactless power supply system (100) comprising: A power receiving device having a power receiving coil disposed inside the moving body; a plurality of power transmission devices, the plurality of power transmission devices including a power transmission coil, the power transmission coil being arranged within the moving range of the moving body and being magnetically coupled with the power receiving coil of the power receiving device of the moving body to transmit power in a contactless manner; a main power line that supplies AC power of a first voltage used for the power transmission to the plurality of power transmission devices; as well as A DC power supply unit receives AC power from the main power supply line and outputs power of a second voltage which is a voltage lower than the first voltage and is used for control in the power transmission device.

13. The contactless power supply system according to claim 12, wherein: The plurality of power transmission devices are connected in parallel to the main power line, The DC power supply unit is provided corresponding to the power transmission device, or is provided in the power transmission device.

14. A non-contact power supply method, The contactless power supply method supplies AC power of a first voltage to a plurality of power transmission devices disposed within a moving range of a moving body via a main power line. The DC power supply unit receives the AC power from the main power line and outputs power of a second voltage which is an operating voltage of a control unit (58) in the power transmission device and is lower than the first voltage. Under the control of the control unit, at least one of the plurality of power transmission devices uses the AC power of the first voltage to supply high-frequency AC power to a power transmission coil provided in the power transmission device. Power is transmitted to a power receiving coil of a power receiving device of the moving object in a contactless manner via the power transmission coil.

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