Power supply station

Abstract

To provide a power supply station which can guide a stop position of an electrically-driven mobility so as to improve efficiency of power transmission while enabling power to be supplied in a non-contact manner to the electrically-driven mobility via a power supply coil.SOLUTION: A power supply device 11 of a power supply station 2 comprises: a power supply coil 32 which supplies power to a power reception device 21 of an electrically-driven mobility 3; a power supply circuit 31 which supplies AC power to the power supply coil 32; and a control circuit 34 which controls the frequency and voltage of the AC power. The control circuit 34 executes via a notification unit 12 notification for guiding a stop position of the electrically-driven mobility 3 to a housing 10 so as to improve efficiency of power transmission to the power reception device 21 from the power supply device 11 according to the frequency of the AC power supplied to the power supply coil 32 in a case where the output voltage from the power reception device 21 becomes constant or the voltage of the AC power supplied to the power supply coil 32 in a case where the output voltage from the power reception device 21 becomes constant and becomes prescribed voltage.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a power supply station for supplying power to electric mobility in a non-contact manner.

Background Art

[0002] In order to supply power to a two-wheeled vehicle to drive a motor that assists the power of the two-wheeled vehicle, equipment for supplying power to the two-wheeled vehicle in a non-contact manner has been proposed (see Patent Documents 1 and 2).

[0003] Patent Document 1 discloses a power supply stand provided with a power transmission circuit in order to supply power to a bicycle provided with a power reception circuit. Further, the wireless power supply system disclosed in Patent Document 2 includes a transmission device and a reception device that receives and charges the power wirelessly transmitted by the transmission device, and an electric bicycle that performs electric assist using the charged power.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In an example of a system for supplying power in a non-contact manner, a coil is provided in each of the power supply side device and the power reception side device. Then, by supplying alternating current power to the power supply side coil (hereinafter referred to as the power supply coil) in the power supply side device, a magnetic field is generated in the power supply coil. Then, when the coil (hereinafter referred to as the power reception coil) provided in the power reception side device (hereinafter referred to as the power reception device) resonates with the magnetic field, power is supplied from the power supply device to the power reception device in a non-contact manner.

[0006] Such a non-contact power supply system can transmit power even if the positional relationship between the power supply coil on the power transmission side and the power receiving coil on the power receiving side changes to some extent. However, the efficiency of power transmission changes depending on the positional relationship between the power supply coil and the power receiving coil. Therefore, it is preferable to be able to guide the stop position of the two-wheeled vehicle to the user of the two-wheeled vehicle so that the efficiency of power transmission is good.

[0007] Therefore, an object of the present invention is to provide a power supply station that can supply power to an electric mobility non-contact via a power supply coil and can guide the stop position of the electric mobility so that the efficiency of power transmission is improved.

Means for Solving the Problems

[0008] As one aspect of the present invention, there is provided a power supply station capable of supplying power to a power receiving device having a power receiving coil provided in an electric mobility. This power supply station has a power supply device that supplies power to the electric mobility via the power receiving coil, and a housing that houses the power supply device. The power supply device has a power supply coil that supplies power to the power receiving device via the power receiving coil, a power supply circuit that supplies AC power to the power supply coil, and a control circuit that controls the frequency and voltage of the AC power supplied to the power supply coil. And the control circuit, when the output voltage from the power receiving device becomes constant, the frequency of the AC power supplied to the power supply coil, or when the output voltage from the power receiving device is constant and becomes a predetermined voltage, according to the voltage of the AC power supplied to the power supply coil, a notification for guiding the stop position of the electric mobility with respect to the housing so that the power transmission efficiency from the power supply device to the power receiving device is improved is executed via a notification unit provided in the power supply station or the electric mobility. By having such a configuration, this power supply station can supply power to the electric mobility non-contact via the power supply coil, and can suppress foreign matter from entering between the power receiving coil provided in the electric mobility and the power supply coil.

[0009] In this power supply station, when the output voltage from the power receiving device is constant and the frequency of the AC power supplied to the power supply coil is lower than a predetermined frequency threshold, it is preferable that the control circuit executes, via the notification unit, a notification for guiding the stop position of the electric mobility so that the power supply coil and the power receiving coil approach each other. By having such a configuration, this power supply station can guide the electric mobility to a stop position where the power transmission efficiency is improved.

[0010] Also, in this power supply station, when the output voltage from the power receiving device is constant and becomes a predetermined voltage, and the voltage of the AC power supplied to the power supply coil is higher than a predetermined voltage threshold, it is preferable that the control circuit executes, via the notification unit, a notification for guiding the stop position of the electric mobility so that the power supply coil and the power receiving coil approach each other. By having such a configuration, this power supply station can guide the electric mobility to a stop position where the power transmission efficiency is improved.

[0011] Alternatively, in this power supply station, the control circuit records the time change of the frequency of the AC power supplied to the power supply coil when the output voltage from the power receiving device is constant, and determines the moving direction of the electric mobility with respect to the housing for improving the efficiency of power transmission from the power supply device to the power receiving device according to the time change of the frequency, and it is preferable that the control circuit executes, via the notification unit, a notification for moving the electric mobility along the moving direction. By having such a configuration, this power supply station can determine the direction in which the electric mobility is moved to a stop position where the power transmission efficiency is improved, and can guide the electric mobility in that direction.

[0012] Alternatively, in this power supply station, when the output voltage from the power receiving device is constant and reaches a predetermined voltage, the control circuit records the temporal change in the voltage of the AC power supplied to the power supply coil, and determines the moving direction of the electric mobility with respect to the housing for improving the power transmission efficiency from the power supply device to the power receiving device according to the temporal change in the voltage, and preferably executes a notification to move the electric mobility along the moving direction via the notification unit. By having such a configuration, this power supply station can determine the direction in which the electric mobility is to be moved to a stop position where the power transmission efficiency is improved, and can guide the electric mobility in that direction.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0014] Hereinafter, a power feeding station according to an embodiment of the present invention will be described with reference to the drawings. This power feeding station has a power feeding device for feeding power to a two-wheeled vehicle inside a housing, and transmits power to the two-wheeled vehicle via the power feeding coil of the power feeding device and the power receiving coil of the power receiving device provided on the parked two-wheeled vehicle. Further, the power feeding device of the power feeding station and the power receiving device of the two-wheeled vehicle set the frequency of the alternating current power supplied to the power feeding coil to a predetermined frequency according to the degree of coupling between the power feeding coil and the power receiving coil, so that the voltage output from the power receiving device becomes constant regardless of the resistance of the load connected to the power receiving device, and it is possible to perform a constant voltage output operation. Therefore, this power feeding station identifies the frequency of the alternating current power supplied to the power feeding coil at which the power feeding device and the power receiving device perform a constant voltage output operation, and based on the identified frequency, notifies the two-wheeled vehicle to be induced to a position where the power transmission efficiency is improved.

[0015] FIG. 1 is a schematic configuration diagram of a non-contact power feeding system including the power feeding station and the two-wheeled vehicle according to this embodiment.

[0016] As shown in FIG. 1, the non-contact power feeding system 1 has a power feeding station 2 and a two-wheeled vehicle 3. The power feeding station 2 is capable of feeding power to the two-wheeled vehicle 3, and has a housing 10, a power feeding device 11 provided inside the housing 10 and having a power feeding coil 32, and a display device 12.

[0017] On the one hand, the two-wheeled vehicle 3 is an example of electric mobility, and includes a power receiving device 21 having a power receiving coil 41 and a battery 22 for storing the power received by the power receiving device 21. Further, a front basket 24 is provided above the front wheel 23 of the two-wheeled vehicle 3, and a box 25 formed of an insulator such as resin is attached to the lower surface of the front basket 24. The power receiving device 21 is accommodated in the box 25. Furthermore, the power receiving coil 41 of the power receiving device 21 is attached to the two-wheeled vehicle 3 between the front wheel 23 and the front basket 24 of the two-wheeled vehicle 3 such that the winding axis of the power receiving coil 41 faces the front of the two-wheeled vehicle 3. Also, the battery 22 is attached to a loading platform provided on the upper surface of the rear wheel of the two-wheeled vehicle 3 and is charged by the power received via the power receiving device 21. The power stored in the battery 22 is used to drive a motor (not shown) that provides auxiliary power for the two-wheeled vehicle 3 or to turn on the headlight 26. Then, by parking the two-wheeled vehicle 3 so as to have a predetermined positional relationship with respect to the power feeding station 2, power is fed non-contact from the power feeding coil 32 of the power feeding device 11 to the power receiving coil 41 of the power receiving device 21.

[0018] FIG. 2 is a schematic front view of the power feeding station 2 as seen from the side of the two-wheeled vehicle 3 being parked. FIG. 3 is a schematic side view of the power feeding station 2. Further, FIG. 4 is a schematic perspective view of the power feeding station 2 showing a state in which the two-wheeled vehicle 3 is parked at the power feeding station 2. Furthermore, FIG. 5 is an enlarged view showing a part of the power feeding station 2 and the two-wheeled vehicle 3 related to the power supply from the power feeding station 2 to the two-wheeled vehicle 3 in a state where the two-wheeled vehicle 3 is parked at the power feeding station 2. In the following, the surface of the housing 10 facing the two-wheeled vehicle 3 parked at the power feeding station 2 may be referred to as the front of the housing 10.

[0019] The housing 10 of the power supply station 2 is formed to specify a predetermined position where the two-wheeled vehicle 3 is parked. In the present embodiment, as shown in FIGS. 2 to 4, the housing 10 has an inverted U-shaped overall shape when viewed from the front side. The housing 10 is provided in a substantially vertical direction with respect to the road surface on which the power supply station 2 is installed, and includes two substantially quadrangular columnar support portions 13 and 14, and an upper end portion 15 that connects the two support portions 13 and 14 at its upper portion. When the two-wheeled vehicle 3 is parked at the power supply station 2, the front wheel of the two-wheeled vehicle 3 is inserted into the gap between the two support portions 13 and 14 of the housing 10. That is, the gap between the two support portions 13 and 14 represents the position of the front wheel of the two-wheeled vehicle 3 when the two-wheeled vehicle 3 is parked.

[0020] The support portions 13 and 14 and the upper end portion 15 are each formed in a hollow shape from a material such as metal, resin, or a combination thereof, such as aluminum or stainless steel. A power cable (not shown) for transmitting power from a commercial power supply or a DC power supply to the power supply device 11 is accommodated inside one of the support portions 13 and 14. A substrate (not shown) is attached inside the support portion 13 or 14 or the upper end portion 15, and a power supply circuit of the power supply device 11 is provided on the substrate. Grooves 13a and 14a may be provided on the surfaces of the support portions 13 and 14 facing each other so as to engage with the shaft of the front wheel of the two-wheeled vehicle 3 when the two-wheeled vehicle 3 is parked. The grooves 13a and 14a may be formed such that the width becomes narrower as it approaches the surface opposite to the front side (hereinafter referred to as the back side) from the front side.

[0021] The power receiving coil 41 of the power receiving device 21 of the two-wheeled vehicle 3 parked at the power supply station 2 and the power supply coil 32 of the power supply device 11 face each other. On the front side of the upper end portion 15 of the housing 10, a substantially rectangular parallelepiped housing portion 16 is formed so as to protrude toward the two-wheeled vehicle 3 side where parking is to be done. And inside the housing portion 16, the power supply coil 32 is housed. At this time, the power supply coil 32 is installed so that its winding axis is orthogonal to the front side surface 16a (hereinafter sometimes referred to as the surface) of the housing portion 16. Note that the housing portion 16 is formed of an insulator such as resin so as not to be affected by the power supply from the power supply device 11 to the power receiving device 21.

[0022] Furthermore, a cover 17 may be formed on the housing portion 16 so as to surround at least a part including the upper end of its outer periphery and protrude further toward the two-wheeled vehicle 3 side than the surface 16a of the housing portion 16.

[0023] Also, a display device 12 is provided on the front of the upper end portion 15, on the side of the housing portion 16. The display device 12 is an example of a notification unit, and can be, for example, a liquid crystal display or an organic EL display. And the display device 12 displays a message regarding the guidance of the parking position (that is, the stop position) of the two-wheeled vehicle 3 received from the power supply device 11. Note that the position of the display device 12 is not limited to this example, and the display device 12 may be provided on the top surface of the upper end portion 15.

[0024] Next, the details of the power supply device 11 and the power receiving device 21 will be described.

[0025] In this embodiment, the power supply device 11 and the power receiving device 21 are configured as a non-contact power supply device of a method (NS method) in which the power receiving coil 41 and the resonance capacitor 42 are in series resonance on the power receiving side without using resonance on the power supply side. However, it is not limited to this example, and the power supply device 11 and the power receiving device 21 may be, for example, a non-contact power supply device of a so-called primary series secondary series resonance capacitor method (SS method) or a primary series secondary parallel resonance capacitor method (SP method). Alternatively, the power supply device 11 and the power receiving device 21 may be a non-contact power supply device of a method (NP method) in which the power receiving coil 41 and the resonance capacitor 42 are in parallel resonance on the power receiving side without using resonance on the power supply side.

[0026] First, the power supply device 11 provided in the power supply station 2 will be described. FIG. 6 is a schematic configuration diagram of the power supply device 11. The power supply device 11 includes a power supply circuit 31, a power supply coil 32, a communicator 33, and a control circuit 34.

[0027] The power supply circuit 31 supplies AC power having an adjustable frequency and an adjustable voltage to the power supply coil 32. For this purpose, the power supply circuit 31 includes a full-wave rectifier circuit 311 that converts the AC power supplied from the commercial power supply into pulsating DC power, a power factor correction circuit 312, and an inverter circuit 313.

[0028] The full-wave rectifier circuit 311 is connected between the commercial power supply and the power factor correction circuit 312, and converts the AC power supplied from the commercial power supply into pulsating DC power. For this purpose, the full-wave rectifier circuit 311 is composed of four diodes connected in a bridge shape. And the full-wave rectifier circuit 311 outputs the pulsating DC power to the power factor correction circuit 312.

[0029] The power factor improvement circuit 312 is connected between the full-wave rectifier circuit 311 and the inverter circuit 313, and converts the pulsating current power output from the full-wave rectifier circuit 311 into DC power and boosts it by improving the power factor of the pulsating current power. For this purpose, the power factor improvement circuit 312 includes, for example, a coil L and a diode D connected in series in order from the positive output terminal of the full-wave rectifier circuit 311, a switching element SW which is an n-channel MOSFET with its drain terminal connected between the coil L and the diode D and its source terminal connected to the negative output terminal of the full-wave rectifier circuit 311, and a smoothing capacitor C connected in parallel with the switching element SW with the diode D sandwiched therebetween. The gate terminal of the switching element SW is connected to the control circuit 34. Further, the power factor improvement circuit 312 has two resistors R1 and R2 connected in series between the positive output terminal and the negative output terminal of the full-wave rectifier circuit 311. These resistors R1 and R2 are connected in parallel with the smoothing capacitor C between the diode D and the smoothing capacitor C. And the voltage between the resistor R1 and the resistor R2 is measured by the control circuit 34 as representing the voltage output from the diode D.

[0030] The control circuit 34 controls the on / off of the switching element SW so that the power factor improvement circuit 312 performs a power factor improvement operation according to the duty ratio specified by the control circuit 34 and the locus of the current waveform output from the diode D coincides with the locus of the voltage of the pulsating current power supplied from the full-wave rectifier circuit 311. And the higher the duty ratio at which the switching element SW is on, the higher the voltage output from the diode D.

[0031] The power output from the diode D is smoothed by the smoothing capacitor C to become DC power and is output to the inverter circuit 313.

[0032] Note that the power factor improvement circuit 312 is not limited to the above configuration, and may have other configurations capable of adjusting the output voltage under the control from the control circuit 34.

[0033] The inverter circuit 313 is connected between the power factor correction circuit 312 and the power supply coil 32, and converts the DC power supplied from the power factor correction circuit 312 into AC power having a predetermined frequency and supplies it to the power supply coil 32. For this purpose, the inverter circuit 313 can be a full-bridge inverter in which four switching elements (for example, n-channel MOSFETs) are connected in a full-bridge configuration. Alternatively, the inverter circuit 313 may be a half-bridge inverter in which two switching elements are connected in a half-bridge configuration. Then, the inverter circuit 313 converts the DC power supplied from the power factor correction circuit 312 into AC power having a predetermined frequency by controlling the on / off switching of each switching element according to a predetermined frequency by the control circuit 34. The predetermined frequency is the frequency at which the power supply device 11 and the power receiving device 21 operate with constant voltage output, and is defined according to the coupling degree between the power supply coil 32 and the power receiving coil 41. Hereinafter, for convenience of explanation, this predetermined frequency will be referred to as the constant voltage frequency.

[0034] The power supply circuit 31 may further include a DC-DC converter for boosting or bucking the voltage of the DC power output from the power factor correction circuit 312 between the power factor correction circuit 312 and the inverter circuit 313. Alternatively, the power supply circuit 31 may include an AC-DC converter that converts AC power supplied from a commercial AC power source into DC power instead of the full-wave rectifier circuit 311 and the power factor correction circuit 312. Alternatively, the power supply circuit 31 may include a DC power source that supplies DC power, such as a lithium-ion secondary battery or a lead-acid battery, and a DC-DC converter for boosting or bucking the voltage of the DC power supplied from the DC power source instead of the full-wave rectifier circuit 311 and the power factor correction circuit 312.

[0035] The power supply coil 32 transmits the AC power supplied from the power supply circuit 31 to the power receiving coil 41 of the power receiving device 21 through space. Note that the power supply device 11 may have a capacitor connected in series with the power supply coil 32 between the power supply coil 32 and the inverter circuit of the power supply circuit 31. This capacitor may be for blocking DC power, or may be for forming a resonance circuit that resonates with the power supply coil 32 at the frequency of the AC power supplied to the power supply coil 32.

[0036] Each time the communicator 33 receives a wireless signal from the communicator of the power receiving device 21, it extracts a signal representing the power receiving status of the power receiving device 21 from the wireless signal and outputs it to the control circuit 34. For this purpose, the communicator 33 has, for example, an antenna that receives wireless signals according to a predetermined wireless communication standard, and a communication circuit that demodulates the wireless signals. Note that the predetermined wireless communication standard can be, for example, ISO / IEC 15693, ZigBee (registered trademark), or Bluetooth (registered trademark).

[0037] The control circuit 34 has, for example, a non-volatile memory circuit, a volatile memory circuit, an arithmetic circuit, and an interface circuit for connecting to other circuits. Then, based on the signal representing the power receiving status of the power receiving device 21 received from the power receiving device 21 via the communicator 33, the control circuit 34 controls the on / off switching of each switching element of the inverter circuit 313 so that the power supply device 11 and the power receiving device 21 operate with constant voltage output. That is, the control circuit 34 controls the on / off switching of each switching element of the inverter circuit 313 so that the frequency of the AC power supplied to the power supply coil 32 becomes the constant voltage frequency. Further, the control circuit 34 may control the on / off of the switching element SW of the power factor correction circuit 312 to adjust the voltage of the DC power supplied to the inverter circuit 313 in order to keep the voltage of the power received by the power receiving device 21 constant.

[0038] Furthermore, the control circuit 34 determines whether the parking position of the two-wheeler 3 is appropriate with reference to the constant voltage frequency, and when it is determined that the parking position is not appropriate, causes the display device 12 to display a message prompting the movement of the parking position of the two-wheeler 3 to an appropriate position.

[0039] Note that the details of the operation of the control circuit 34 will be described later.

[0040] Next, the power receiving device 21 provided in the two-wheeler 3 will be described. FIG. 7 is a schematic configuration diagram of the power receiving device 21. The power receiving device 21 includes a power receiving coil 41, a resonance capacitor 42, a power receiving circuit 43, and a communicator 44. The power receiving coil 41 forms a resonance circuit together with the resonance capacitor 42.

[0041] The power receiving coil 41 forms a resonance circuit together with the resonance capacitor 42, and receives power from the power feeding coil 32 by resonating with the alternating current flowing through the power feeding coil 32 of the power feeding device 11. For this purpose, the resonance capacitor 42 is connected in series with the power receiving coil 41. Note that the resonance capacitor 42 may be connected in parallel with the power receiving coil 41. The alternating current power output from the resonance circuit formed by the power receiving coil 41 and the resonance capacitor 42 is output to the power receiving circuit 43. Note that the number of turns of the power receiving coil 41 and the number of turns of the power feeding coil 32 may be the same, or may be different from each other.

[0042] The power receiving circuit 43 converts the alternating current power from the resonance circuit formed by the power receiving coil 41 and the resonance capacitor 42 into direct current power, and outputs the direct current power to the battery 22 connected via the power receiving circuit 43, a power cable (not shown), and a charger (not shown) and provided on the side surface of the rear wheel. Furthermore, the power receiving circuit 43 examines the power receiving status from the power feeding device 11, particularly whether the output voltage from the power receiving circuit 43 is constant. For this purpose, the power receiving circuit 43 includes a rectifying and smoothing circuit 431, a voltage detection circuit 432, a switching element 433, and a determination circuit 434.

[0043] The rectifying and smoothing circuit 431 is an example of a rectifying circuit, and includes a full-wave rectifying circuit having switching elements such as four diodes or MOSFETs connected in a bridge configuration and a smoothing capacitor. The rectifying and smoothing circuit 431 rectifies the power received via the power receiving coil 41, smooths it, and converts it into DC power. Then, the rectifying and smoothing circuit 431 outputs the DC power to the battery 22 via a charger.

[0044] The voltage detection circuit 432 measures the output voltage across both terminals of the rectifying and smoothing circuit 431 (i.e., the output voltage of the power receiving circuit 43, hereinafter sometimes simply referred to as the output voltage) at predetermined intervals. Since the output voltage across both terminals of the rectifying and smoothing circuit 431 corresponds one-to-one with the output voltage of the resonance circuit composed of the power receiving coil 41 and the resonance capacitor 42, the measured value of the output voltage across both terminals of the rectifying and smoothing circuit 431 indirectly becomes the measured value of the output voltage of that resonance circuit. The voltage detection circuit 432 can be, for example, any of various known voltage detection circuits capable of detecting a DC voltage. Then, the voltage detection circuit 432 outputs a voltage detection signal representing the measured value of the output voltage to the determination circuit 434.

[0045] The switching element 433 is, for example, a MOSFET and is connected between the rectifying and smoothing circuit 431 and the battery 22. When the switching element 433 is off, it prevents current from flowing from the rectifying and smoothing circuit 431 to the battery 22 (i.e., the AC equivalent resistance value Rac of the battery 22 and the charger is ∞), while when it is on, it allows current to flow from the rectifying and smoothing circuit 431 to the battery 22.

[0046] Based on the measured value of the output voltage received from the voltage detection circuit 432, the determination circuit 434 determines whether the power supply device 11 and the power receiving device 21 are operating in a constant voltage output mode and whether the measured value of the output voltage is within the allowable voltage range. Then, the determination circuit 434 notifies the communication device 44 of the determination result. For this purpose, the determination circuit 434 includes, for example, a memory circuit that stores the allowable voltage range, an arithmetic circuit that compares the measured value of the output voltage with the allowable voltage range, and a control circuit for controlling the on / off of the switching element 433.

[0047] The determination circuit 434 switches the on / off state of the switching element 433 at a predetermined period while the measured value of the output voltage is out of the allowable voltage range. As a result, the resistance value of the entire circuit including the battery 22, which is connected to the rectifying and smoothing circuit 431, changes at that predetermined period. Therefore, the determination circuit 434 can determine whether the power supply device 11 and the power receiving device 21 are operating in a constant voltage output mode by determining whether the measured value of the output voltage becomes substantially constant while switching the on / off state of the switching element 433. Thus, while the measured value of the output voltage remains substantially constant even when the determination circuit 434 switches the on / off state of the switching element 433 at a predetermined period, the determination circuit 434 notifies the communicator 44 that the power supply device 11 and the power receiving device 21 are operating in a constant voltage output mode.

[0048] Also, when the measured value of the output voltage is within a certain period longer than the predetermined period and the power supply device 11 and the power receiving device 21 are operating in a constant voltage output mode, the determination circuit 434 stops switching the on / off state of the switching element 433 and maintains the on state. Then, the determination circuit 434 determines whether the measured value of the output voltage is within the allowable voltage range and notifies the communicator 44 of the determination result.

[0049] At that time, when the measured value of the output voltage is within the allowable voltage range for a certain period longer than the predetermined period, the determination circuit 434 notifies the communicator 44 of a determination result indicating that the power supply device 11 and the power receiving device 21 are operating in a constant voltage output mode and that the measured value of the output voltage is within the allowable voltage range.

[0050] Note that according to a modification example, the power receiving circuit 43 may have a resistor connected in parallel with the battery 22 to the rectifying and smoothing circuit 431. In this case, the switching element 433 may be provided in series with the resistor and in parallel with the battery 22. In this case, while the measured value of the output voltage is within the allowable range of the voltage, the determination circuit 434 turns off the switching element 433. On the other hand, when the measured value of the output voltage deviates from the allowable range of the voltage, the determination circuit 434 may switch the on / off of the switching element 433 at a predetermined cycle, similar to the above-described embodiment. According to this modification example, even when the power supply device 11 and the power receiving device 21 are not operating in a constant voltage output mode, the power supply to the battery 22 is continued.

[0051] According to still another modification example, a second switching element such as a MOSFET may be provided in parallel with the above-described resistor and in series with the battery 22. In this case, while the measured value of the output voltage is within the allowable range of the voltage, the determination circuit 434 turns on the second switching element to enable power supply to the battery 22. On the other hand, when the measured value of the output voltage deviates from the allowable range of the voltage, the determination circuit 434 may turn off the second switching element to stop the power supply to the battery 22. Thereby, even when the voltage of the received power becomes excessively high while the frequency of the AC power applied to the power supply coil 32 in the power supply device 11 is being adjusted, it is possible to prevent the excessively high voltage from being applied to the battery 22.

[0052] The communicator 44 generates a signal representing the power reception status according to the determination result received from the determination circuit 434 at each predetermined transmission cycle. The signal representing the power reception status includes determination information indicating whether the power supply device 11 and the power reception device 21 are operating in a constant voltage output mode and whether the measured value of the output voltage is within the allowable range of the voltage. Then, the communicator 44 generates a wireless signal including the signal representing the power reception status and transmits the wireless signal to the communicator 33 of the power supply device 11. For this purpose, the communicator 44 has, for example, a communication circuit that generates a wireless signal according to a predetermined wireless communication standard and an antenna that outputs the wireless signal. Note that the predetermined wireless communication standard can be, for example, ISO / IEC 15693, ZigBee (registered trademark), or Bluetooth (registered trademark), similar to the communicator 33.

[0053] Hereinafter, the details of the operation of the control circuit 34 of the power supply device 11 will be described. First, the constant voltage output operation will be described.

[0054] FIG. 8 is an equivalent circuit diagram of the power supply device 11 and the power reception device 21. In this equivalent circuit 100, it is assumed that the power supply coil 32 and the power reception coil 41 are coupled to form an ideal transformer of n:1. Lr and Lm are the leakage inductance and the magnetizing inductance of the power supply coil 32. Note that the inductance Lp of the power supply coil 32 is equal to (Lm + Lr). When the coupling coefficient between the power supply coil 32 and the power reception coil 41 is k, Lr = (1 - k)Lp and Lm = kLp. Also, Ri is the winding resistance value of the power supply device 11, and Ris is the winding resistance value of the power reception device 21. Cp is the capacitance of the resonance capacitor 42 of the power reception device 21. And Rac is the AC equivalent resistance value of the battery 22 and the resistance value Ro of the charger, which is represented by Rac = (8 / π2) × Ro.

[0055] FIG. 9 is a diagram showing an example of a simulation result of the frequency characteristics of the output voltage of the power receiving device 21 calculated according to the output gain of the equivalent circuit described above. In FIG. 9, the horizontal axis represents the frequency of the AC power applied to the power feeding coil 32, and the vertical axis represents the output voltage from the power receiving device 21. Graph 901 represents the frequency characteristics of the output voltage when the coupling coefficient k = 0.15 and the AC equivalent resistance values of the battery 22 and the charger are Rac. Graph 902 represents the frequency characteristics of the output voltage when the coupling coefficient k = 0.15 and the AC equivalent resistance values of the battery 22 and the charger are (10 * Rac). Graph 903 represents the frequency characteristics of the output voltage when the coupling coefficient k = 0.3 and the AC equivalent resistance values of the battery 22 and the charger are Rac. Graph 904 represents the frequency characteristics of the output voltage when the coupling coefficient k = 0.3 and the AC equivalent resistance values of the battery 22 and the charger are (10 * Rac). Further, graph 905 represents the frequency characteristics of the output voltage when the coupling coefficient k = 0.6 and the AC equivalent resistance values of the battery 22 and the charger are Rac. Graph 906 represents the frequency characteristics of the output voltage when the coupling coefficient k = 0.6 and the AC equivalent resistance values of the battery 22 and the charger are (10 * Rac). In this simulation, Lp = 174 μH, Cp = 20 nF, Ri = Ris = 0.1 Ω, n = 1, Vin = 300 V, Ro = 10 Ω (Rac ≒ 8.1 Ω).

[0056] As shown by points 911 to 913 in Fig. 9, even if the AC equivalent resistance value of the battery 22 changes under the condition that the coupling degree k is constant, the output voltage remains substantially constant (that is, constant voltage output is achieved when the coupling degree k is constant). Combinations of frequency and output voltage exist for each coupling degree. Therefore, it can be understood that by appropriately adjusting the frequency of the AC power applied to the power feeding coil 32, the power feeding device 11 and the power receiving device 21 perform constant voltage output operation with respect to changes in the resistance values of the battery 22 and the charger. Further, as shown by points 911 to 913, although the output voltages when constant voltage output is achieved with respect to fluctuations in the resistance values of the battery 22 and the charger are different from each other according to the coupling degree, the difference in this output voltage can be canceled by adjusting the voltage applied to the power feeding coil 32. Therefore, it is possible to make the output voltage a substantially constant value regardless of the coupling degree.

[0057] FIG. 10 is a diagram showing an example of a simulation result of the frequency characteristics of the output voltage when the voltage applied to the power supply coil 32 is changed according to the coupling degree in the simulation shown in FIG. 9. In FIG. 10, the horizontal axis represents the frequency of the AC power applied to the power supply coil 32, and the vertical axis represents the output voltage from the power receiving device 21. Graph 1001 represents the frequency characteristics of the output voltage when the coupling degree k = 0.15, the AC equivalent resistance values of the battery 22 and the charger are Rac, and the voltage applied to the power supply coil 32 is Vin. Graph 1002 represents the frequency characteristics of the output voltage when the coupling degree k = 0.15, the AC equivalent resistance values of the battery 22 and the charger are (10 * Rac), and the voltage applied to the power supply coil 32 is Vin. Graph 1003 represents the frequency characteristics of the output voltage when the coupling degree k = 0.3, the AC equivalent resistance values of the battery 22 and the charger are Rac, and the voltage applied to the power supply coil 32 is (0.5 * Vin). Graph 1004 represents the frequency characteristics of the output voltage when the coupling degree k = 0.3, the AC equivalent resistance values of the battery 22 and the charger are (10 * Rac), and the voltage applied to the power supply coil 32 is (0.5 * Vin). Further, graph 1005 represents the frequency characteristics of the output voltage when the coupling degree k = 0.6, the AC equivalent resistance values of the battery 22 and the charger are Rac, and the voltage applied to the power supply coil 32 is (0.25 * Vin). Graph 1006 represents the frequency characteristics of the output voltage when the coupling degree k = 0.6, the AC equivalent resistance values of the battery 22 and the charger are (10 * Rac), and the voltage applied to the power supply coil 32 is (0.25 * Vin).

[0058] Under the condition that the coupling degree k does not change, corresponding to the points 911 to 913 shown in FIG. 9, even if the AC equivalent resistance values of the battery 22 and the charger change, the output voltage becomes substantially constant (that is, constant voltage output). There are three combinations of frequency and output voltage, which are the points 1011 to 1013. And the output voltages of the points 1011 to 1013 are substantially equal to each other.

[0059] Thus, it can be understood that even if any of the resistance values and coupling degrees of the battery 22 and the charger vary, the output voltage is maintained substantially constant by appropriately adjusting the frequency and voltage of the AC power applied to the power supply coil 32.

[0060] As described above, in order to achieve the constant voltage output operation, the control circuit 34 controls the frequency (hereinafter, may be simply referred to as the frequency) and voltage of the AC power applied to the power supply coil 32 as follows.

[0061] When the determination information included in the signal representing the power reception status received from the power reception device 21 via the communicator 33 by the control circuit 34 indicates that the power supply device 11 and the power reception device 21 are not operating in the constant voltage output mode, the control circuit 34 increases the frequency in order from the lower limit to the upper limit of a predetermined frequency range.

[0062] Note that the control circuit 34 preferably changes the frequency stepwise so as to maintain the same frequency for a period longer than the period in which the determination circuit 434 of the power reception device 21 switches the on and off of the switching element 433, so that the determination circuit 434 can examine whether the output voltage has become substantially constant.

[0063] Furthermore, while adjusting the frequency, the control circuit 34 preferably decreases the voltage applied to the power supply coil 32 to the lower limit voltage. Thereby, it is suppressed that the voltage of the power supplied to the power reception device 21 becomes excessively high.

[0064] When the control circuit 34 determines from the determination information included in the signal indicating the power reception status received from the power receiving device 21 via the communicator 33 that although the measured value of the output voltage is not within the allowable range of the voltage, it becomes substantially constant even when the resistance of the battery 22 changes, that is, when it is indicated that the constant voltage output operation is being performed, thereafter, it maintains the frequency constant. Next, the control circuit 34 refers to a reference table showing the relationship between the frequency and the duty ratio of the on / off control of the switching element SW of the power factor improvement circuit 312 that results in a constant voltage output regardless of the coupling degree at that frequency, and determines the duty ratio. Then, the control circuit 34 switches the on / off of the switching element SW of the power factor improvement circuit 312 according to the duty ratio. Thereby, the voltage applied to the power feeding coil 32 is adjusted so that the output voltage from the power receiving device 21 is within the allowable range of the voltage, that is, so that a constant voltage is output regardless of the coupling degree. When the control circuit 34 determines from the determination information included in the signal indicating the power reception status received from the power receiving device 21 via the communicator 33 that the measured value of the output voltage is within the allowable range of the voltage, it maintains the frequency and voltage of the alternating current power supplied to the power feeding coil 32 constant.

[0065] Note that instead of referring to the above reference table to determine the duty ratio, the control circuit 34 may gradually change the duty ratio until it is indicated in the determination information that the measured value of the output voltage is within the allowable range of the voltage.

[0066] When the control circuit 34 detects the frequency (constant voltage frequency) of the alternating current power applied to the power feeding coil 32 at which the power feeding device 11 and the power receiving device 21 perform the constant voltage output operation, it determines whether or not to change the parking position of the two-wheeled vehicle 3 based on that frequency. Then, according to the determination result, the control circuit 34 executes a notification for guiding the stop position of the two-wheeled vehicle 3 with respect to the housing 10 via the display device 12.

[0067] Referring again to Fig. 9, when the voltage of the AC power applied to the power supply coil 32 is constant, it can be seen that the output voltage when the power supply device 11 and the power receiving device 21 operate with a constant voltage output changes according to the coupling degree between the power supply coil 32 and the power receiving coil 41. In particular, the higher the coupling degree between the power supply coil 32 and the power receiving coil 41, the higher the output voltage. Therefore, the higher the coupling degree, the higher the efficiency of power transmission. Also, the coupling degree between the power supply coil 32 and the power receiving coil 41 changes according to the positional relationship between the power supply coil 32 and the power receiving coil 41. In the present embodiment, when the two-wheeled vehicle 3 is parked with respect to the power supply station 2, due to the structure of the housing 10 of the power supply station 2, the two-wheeled vehicle 3 moves so that the power receiving coil 41 approaches the power supply coil 32 from the front direction of the power supply coil 32. That is, when the two-wheeled vehicle 3 is parked, although the distance between the power supply coil 32 and the power receiving coil 41 changes along the winding axis direction of the power supply coil 32, the positional relationship between the power supply coil 32 and the power receiving coil 41 does not change much in the direction orthogonal to the winding axis of the power supply coil 32. Therefore, in the present embodiment, the closer the two-wheeled vehicle 3 approaches the housing 10, the shorter the distance between the power supply coil 32 and the power receiving coil 41, and as a result, the coupling degree between the power supply coil 32 and the power receiving coil 41 increases.

[0068] Therefore, the control circuit 34 compares the constant voltage frequency with a predetermined frequency threshold. As shown in Fig. 9, in the power supply device 11 and the power receiving device 21 according to the present embodiment, the higher the constant voltage frequency, the higher the efficiency of power transmission. Therefore, the predetermined frequency threshold is set as the lower limit value of the constant voltage frequency that satisfies the condition of the power efficiency in which the power transmission efficiency from the power supply device 11 to the power receiving device 21 is predefined. And when the constant voltage frequency is less than the predetermined frequency threshold, the control circuit 34 estimates that the distance between the power supply coil 32 and the power receiving coil 41 is too far. Then, the control circuit 34 causes the display device 12 to display a message prompting the two-wheeled vehicle 3 to move further forward with respect to the power supply station 2.

[0069] On the one hand, when the constant voltage frequency is equal to or higher than a predetermined frequency threshold, the control circuit 34 estimates that the power supply coil 32 and the power receiving coil 41 are close enough to obtain sufficient power transmission efficiency. Then, the control circuit 34 causes the display device 12 to display a message prompting the two-wheeled vehicle 3 to stop at the current position.

[0070] FIG. 11(a) and FIG. 11(b) are diagrams showing an example of the positional relationship between the power supply coil 32 of the power supply station 2 and the power receiving coil 41 of the two-wheeled vehicle 3, and an example of the message displayed on the display device 12 for the positional relationship.

[0071] In the example shown in FIG. 11(a), since the power receiving coil 41 is not close enough to the power supply coil 32, the constant voltage frequency becomes less than the frequency threshold. Therefore, a message prompting the two-wheeled vehicle 3 to move further forward with respect to the power supply station 2, such as "Please move forward a little more", is displayed on the display device 12.

[0072] On the other hand, in the example shown in FIG. 11(b), since the power receiving coil 41 is close enough to the power supply coil 32, the constant voltage frequency becomes equal to or higher than the frequency threshold. Therefore, a message prompting the two-wheeled vehicle 3 to stop at the current position, such as "Please stop at that position", is displayed on the display device 12.

[0073] As described above, this power supply station has a power supply device for supplying power to a two-wheeled vehicle, and transmits power to the two-wheeled vehicle via the power supply coil of the power supply device and the power receiving coil of the power receiving device provided on the parked two-wheeled vehicle. And this power supply station searches for the frequency of the AC power supplied to the power supply coil, where the power supply device and the power receiving device operate with a constant voltage output, and based on the frequency, gives a notification for guiding the two-wheeled vehicle to a position where the power transmission efficiency is improved. In this way, while enabling non-contact power supply to the two-wheeled vehicle via the power supply coil, this power supply station can guide the parking position of the two-wheeled vehicle so as to improve the efficiency of power transmission.

[0074] According to a modified example, the control circuit 34 of the power feeding device 11 may determine whether the parking position of the motorcycle is appropriate based on the voltage of the AC power applied to the power feeding coil 32 when the output voltage from the power receiving device 21 becomes constant.

[0075] Referring to FIGS. 9 and 10 again, it can be seen that the constant voltage frequency and the voltage of the AC power applied to the power feeding coil 32 for setting the output voltage from the power receiving device 21 to a predetermined voltage correspond one-to-one. Also, it can be seen that the higher the coupling degree between the power feeding coil 32 and the power receiving coil 41, the lower the voltage of the AC power applied to the power feeding coil 32 is set. Therefore, when the power feeding device 11 and the power receiving device 21 are operating in a constant voltage output mode, the control circuit 34 compares the voltage of the AC power applied to the power feeding coil 32 for setting the output voltage from the power receiving device 21 to a predetermined voltage with a predetermined voltage threshold. If the voltage of the AC power applied to the power feeding coil 32 is higher than the predetermined voltage threshold, the control circuit 34 causes the display device 12 to display a message prompting the motorcycle 3 to move further forward with respect to the power feeding station 2. On the other hand, if the voltage of the AC power applied to the power feeding coil 32 is equal to or lower than the predetermined voltage threshold, the control circuit 34 causes the display device 12 to display a message prompting the motorcycle 3 to stop at the current position.

[0076] Also in this modified example, the power feeding station can guide the parking position of the motorcycle so as to improve the efficiency of power transmission while enabling non-contact power feeding to the motorcycle via the power feeding coil.

[0077] According to another modification, the power receiving coil 41 of the power receiving device 21 of the two-wheeled vehicle 3 may be attached to the two-wheeled vehicle 3 such that the winding axis direction thereof faces the side surface direction of the two-wheeled vehicle 3. For example, the power receiving coil 41 may be attached to the side surface of the front wheel 23 of the two-wheeled vehicle 3 such that the winding axis is orthogonal to the rotation surface of the front wheel 23 of the two-wheeled vehicle 3. In this case, the power feeding coil 32 of the power feeding device 11 of the power feeding station 2 may be provided such that the power receiving coil 41 and the power feeding coil 32 face each other when the two-wheeled vehicle 3 is parked at an appropriate position in power transmission. For example, the power feeding coil 32 may be attached near the front wheel 23 of the two-wheeled vehicle 3 to be parked inside one of the support portions 13 and 14 of the housing 10 in the above embodiment. In this case, the power feeding coil 32 is installed such that the winding axis thereof is orthogonal to the surface of the support portion of the housing 10 facing the front wheel 23 of the two-wheeled vehicle 3.

[0078] In this case, even if the two-wheeled vehicle 3 is parked such that the power receiving coil 41 of the two-wheeled vehicle 3 goes too far back compared to the power feeding coil 32, or even if the two-wheeled vehicle 3 is parked such that the power receiving coil 41 of the two-wheeled vehicle 3 is too far forward with respect to the power feeding coil 32, the power transmission efficiency becomes insufficient. And depending on whether the power receiving coil 41 is located on the back side or the front side of the power feeding coil 32, the moving direction of the two-wheeled vehicle 3 for bringing the power receiving coil 41 closer to the power feeding coil 32 will be different.

[0079] Therefore, according to this modification, the control circuit 34 records the time change of the constant voltage frequency in the memory of the control circuit 34. And the control circuit 34 determines the direction in which the two-wheeled vehicle 3 is to be moved with reference to the time change of the constant voltage frequency.

[0080] For example, when the power receiving coil 41 is located on the back side of the power feeding coil 32, the power receiving coil 41 will pass through the position closest to the power feeding coil 32. Therefore, the constant voltage frequency will first increase and then decrease. On the other hand, when the power receiving coil 41 is located on the front side of the power feeding coil 32, since the power receiving coil 41 does not reach the position closest to the power feeding coil 32, the constant voltage frequency will not increase so much. Thus, if there is a maximum value of the constant voltage frequency in the time variation of the constant voltage frequency during the most recent predetermined period, the maximum value is equal to or higher than a predetermined frequency threshold, and the current constant voltage frequency is less than the frequency threshold, the control circuit 34 causes the display device 12 to display a message prompting the two-wheeled vehicle 3 to reverse with respect to the power feeding station 2. On the other hand, if the constant voltage frequency does not become equal to or higher than the predetermined frequency threshold in the time variation of the constant voltage frequency during the most recent predetermined period, the control circuit 34 causes the display device 12 to display a message prompting the two-wheeled vehicle 3 to further move forward with respect to the power feeding station 2. Also, when the current constant voltage frequency is equal to or higher than the frequency threshold, the control circuit 34 causes the display device 12 to display a message prompting the two-wheeled vehicle 3 to stop at the current position.

[0081] Similarly, when the power supply device 11 and the power receiving device 21 are operating in a constant voltage output mode, the control circuit 34 may record in the memory of the control circuit 34 the time variation of the voltage of the AC power applied to the power supply coil 32 to make the output voltage from the power receiving device 21 a predetermined voltage. Then, the control circuit 34 may determine the direction in which the two-wheeled vehicle 3 is to be moved with reference to the time variation of the voltage of the AC power. In this case, if there is a minimum value of the voltage in the time variation of the voltage of the AC power during the most recent predetermined period, the minimum value is equal to or lower than a predetermined voltage threshold, and the current voltage of the AC power is higher than the voltage threshold, the control circuit 34 causes the display device 12 to display a message prompting the two-wheeled vehicle 3 to move backward with respect to the power supply station 2. On the other hand, if the voltage does not become equal to or lower than the predetermined voltage threshold in the time variation of the voltage of the AC power during the most recent predetermined period, the control circuit 34 causes the display device 12 to display a message prompting the two-wheeled vehicle 3 to move further forward with respect to the power supply station 2. Further, if the current voltage of the AC power is equal to or lower than the voltage threshold, the control circuit 34 causes the display device 12 to display a message prompting the two-wheeled vehicle 3 to stop at the current position.

[0082] According to this modification, the power supply station can appropriately determine the direction in which the two-wheeled vehicle is to be moved with respect to the power supply station in order to improve the power transmission efficiency.

[0083] Also, in the above-described embodiment or modification, the power supply station 2 may have one or more light sources instead of the display device 12. In this case, the light source serves as another example of the notification unit. And the control circuit 34 varies the lighting state of the light source depending on whether the constant voltage frequency is less than a predetermined frequency threshold and whether the constant voltage frequency is greater than or equal to the predetermined frequency threshold. For example, when the constant voltage frequency is less than the predetermined frequency threshold, the control circuit 34 may blink the light source or light it in red to encourage the motorcycle 3 to move forward more. On the other hand, when the constant voltage frequency is greater than or equal to the predetermined frequency threshold, the control circuit 34 may keep the light source lit constantly or light it in blue or green to encourage the motorcycle 3 to park at the current position. Alternatively, the power supply station 2 may have a speaker instead of the display device 12 or together with the display device 12. The speaker is yet another example of the notification unit. And the control circuit 34 may execute a notification for guiding the parking position of the motorcycle 3 by the sound emitted from the speaker.

[0084] According to still another modification, the display device 12 may be provided on the two-wheeled vehicle 3. For example, the display device 12 may be attached to face upward at the handle of the two-wheeled vehicle 3. In this case, the control circuit 34 of the power feeding device 11 transmits a signal including a notification for guiding the stop position of the two-wheeled vehicle 3 to the communicator 44 of the power receiving device 2 provided on the two-wheeled vehicle 3 via the communicator 33. When the communicator 44 receives the signal from the communicator 33, the communicator 44 outputs a notification for guiding the stop position of the two-wheeled vehicle 3 included in the signal to the display device 12. Then, the display device 12 may display the notification. Furthermore, the display device 12 may be provided on both the power feeding station 2 and the two-wheeled vehicle 3. And each of the display devices 12 of the power feeding station 2 and the two-wheeled vehicle 3 may output a notification for guiding the stop position of the two-wheeled vehicle 3. Note that, similar to the above modification, a light source or a speaker may be provided on the two-wheeled vehicle 3 instead of the display device 12 or together with the display device 12. And the light source or the speaker may output a notification for guiding the stop position of the two-wheeled vehicle 3 included in the signal received via the communicator 44. Also in this modification, the power feeding station 2 can achieve the same effects as those in the above embodiment.

[0085] According to still another modification, as disclosed in Japanese Patent Application Laid-Open No. 2018-207764, the control circuit 34 of the power feeding device 11 may detect the constant voltage frequency by monitoring the current flowing through the power feeding coil 32. In this case, a current detection circuit (not shown) for detecting the current flowing through the power feeding coil 32 is provided in the power feeding device 11. Also, a fixed load circuit (not shown) is provided in the power receiving circuit 43 of the power receiving device 21. And the control circuit 34 may set the frequency of the AC power applied to the power feeding coil 32, which becomes the maximum value of the current flowing through the power feeding coil 32 measured by the current detection circuit, as the constant voltage frequency in a state where a constant load by the fixed load circuit is connected to the resonance circuit including the power receiving coil 41 and the resonance capacitor 42.

[0086] According to still another modification example, the power supply station may supply power to vehicles other than two-wheeled vehicles. For example, the power supply station may supply power to an electric kick scooter. The electric kick scooter is another example of electric mobility. Also in this case, if the electric kick scooter is placed at the power supply station so that the power receiving coil mounted on the electric kick scooter approaches the power supply coil from a predetermined direction, the power supply station can guide the position of the electric kick scooter so as to improve the power transmission efficiency, similarly to the above-described embodiment or modification example.

[0087] As described above, those skilled in the art can make various changes according to the implemented forms within the scope of the present invention.

Description of Reference Numerals

[0088] 1 Non-contact power supply system 2 Power supply station 3 Two-wheeled vehicle 10 Housing 11 Power supply device 12 Display device 13, 14 Support portions 13a, 14a Grooves 15 Upper end portion 16 Accommodating portion 16a Surface of the accommodating portion 17 Cover 31 Power supply circuit 32 Power supply coil 33 Communicator 34 Control circuit 311 Full-wave rectifier circuit 312 Power factor improvement circuit 313 Inverter circuit 21 Power receiving device 22 Battery 23 Front wheel 24 Front basket 25 Box 26 Headlight 41 Power receiving coil 42 Resonance capacitor 43 Power receiving circuit 44 Communicator 431 Rectifying and smoothing circuit 432 Voltage detection circuit 433 Switching element 434 Judgment circuit

Claims

1. A power supply station capable of supplying power to a power receiving device having a power receiving coil provided in an electric mobility, a power supply device for supplying power to the electric mobility via the power receiving coil; a housing in which the power supply device is accommodated; and having, the power supply device includes a power supply coil for supplying power to the power receiving device via the power receiving coil; a power supply circuit for supplying AC power to the power supply coil; a control circuit for controlling the frequency and voltage of the AC power supplied to the power supply coil; and having, the control circuit, in response to the frequency of the AC power when the output voltage from the power receiving device becomes constant, or the voltage of the AC power when the output voltage from the power receiving device becomes constant and reaches a predetermined voltage, executes a notification for guiding the stop position of the electric mobility with respect to the housing so as to improve the efficiency of power transmission from the power supply device to the power receiving device, via a notification unit provided in the power supply station or the electric mobility. A power supply station.

2. The power supply station according to claim 1, wherein when the frequency of the AC power when the output voltage from the power receiving device becomes constant is lower than a predetermined frequency threshold, the control circuit executes a notification for guiding the stop position of the electric mobility so that the power supply coil and the power receiving coil approach each other, via the notification unit.

3. The power supply station according to claim 1, wherein when the voltage of the AC power when the output voltage from the power receiving device becomes constant and reaches a predetermined voltage is higher than a predetermined voltage threshold, the control circuit executes a notification for guiding the stop position of the electric mobility so that the power supply coil and the power receiving coil approach each other, via the notification unit.

4. The power supply station according to claim 1, wherein the control circuit records the time change of the frequency of the AC power when the output voltage from the power receiving device becomes constant, determines the moving direction of the electric mobility with respect to the housing for improving the efficiency of power transmission from the power supply device to the power receiving device according to the time change of the frequency, and executes a notification for moving the electric mobility along the moving direction, via the notification unit.

5. The control circuit records a temporal change in the voltage of the AC power when the output voltage from the power receiving device is constant and becomes a predetermined voltage, and determines a moving direction of the electric mobility with respect to the housing for improving the efficiency of power transmission from the power supply device to the power receiving device according to the temporal change in the voltage, and executes a notification to move the electric mobility along the moving direction via the notification unit. The power supply station according to claim 1.

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