JP5767469B2 - Power supply system - Google Patents

Description

  The present invention relates to a power feeding system, and more particularly to a power feeding system that supplies power from a power feeding coil to a power receiving coil in a contactless manner.

  As the power feeding system described above, for example, the one shown in FIG. 10 is known (Patent Documents 1 and 2). As shown in the figure, the power feeding system 1 includes a power feeding unit 3 as a power feeding unit and a power receiving unit 5 as a power receiving unit. The power feeding unit 3 includes a power feeding side loop antenna 6 to which power is supplied and a power feeding side helical coil 7 as a power feeding side coil electromagnetically coupled to the power feeding side loop antenna 6. When power is supplied to the power feeding side loop antenna 6, the power is sent to the power feeding side helical coil 7 by electromagnetic induction.

  The power reception unit 5 includes a power reception side helical coil 9 that electromagnetically resonates with the power supply side helical coil 7, and a power reception side loop antenna 10 that is electromagnetically coupled to the power reception side helical coil 9. When power is sent to the power supply side helical coil 7, the power is wirelessly sent to the power receiving side helical coil 9 by magnetic field resonance.

  Further, when power is sent to the power receiving side helical coil 9, the power is sent to the power receiving side loop antenna 10 by electromagnetic induction and supplied to a load connected to the power receiving side loop antenna 10. According to the power feeding system 1 described above, power from the power feeding side can be supplied to the power receiving side in a non-contact manner by electromagnetic resonance between the power feeding side helical coil 7 and the power receiving side helical coil 9.

  Then, it is conceivable that the power receiving unit 5 described above is provided in the automobile and the power supply unit 3 is provided on the road or the like, thereby supplying power to the load mounted on the automobile wirelessly using the power supply system 1 described above. Yes.

By the way, the distance between the power receiving unit 5 provided in the automobile described above and the power feeding unit 3 provided on the road varies depending on the type of automobile. That is, the inter-coil distance L ₁ between the power reception side helical coil 9 of the power reception unit 5 and the power supply side helical coil 7 of the power supply unit 3 also varies depending on the vehicle type. For example, when the power receiving unit 5 is provided in a vehicle with a low vehicle height such as a sports car, the inter-coil distance L ₁ is shortened. When the power receiving unit 5 is provided in a vehicle with a high vehicle height such as an RV vehicle, the inter-coil distance is provided. L ₁ becomes longer.

Next, the inventors set the inter-coil distance L ₁ with the antenna diameters R ₁₁ and R ₁₂ of the power feeding side and power receiving side loop antennas 6 and 10 of the power feeding system 1 shown in FIG. The passage characteristic S21 and the reflection characteristic S11 of the power receiving side loop antenna 10 when it was changed in the range of 100 mm to 400 mm were measured. The results are shown in FIGS.

As can be seen from FIG. 11, in the power supply system 1 described above, when the inter-coil distance L ₁ changes, the pass characteristic S21 changes. As shown in FIGS. 12 and 13, the main cause is misalignment between the power supply side helical coil 7 and the power reception side helical coil 9.

More specifically, assuming that the antenna diameters R ₁₁ and R ₁₂ of the power supply side loop antenna 6 and the power reception side loop antenna 10 are 206 mm, when the distance L ₁ between the coils is 200 mm, the state is close to critical coupling. However, when the inter-coil distance L ₁ is shortened, the coupling between the power feeding unit 3 and the power receiving unit 5 becomes dense, and exhibits a bi-resonance characteristic. Therefore, the frequency at which the pass characteristic S21 becomes 1 changes.

Accordingly, when the operating frequency is fixed at around 13.5 MHz, when the inter-coil distance L ₁ is 200 mm, the pass characteristic S21 is almost 1 and high efficiency, but when the inter-coil distance L ₁ varies to 100 mm, the pass characteristic is obtained. S21 falls to 0.65 and the loss increases.

On the other hand, when the inter-coil distance L ₁ is increased, the coupling between the power supply side helical coil 7 and the power reception side helical coil 9 becomes sparse, the impedance matching between them cannot be achieved, the pass characteristic S21 is lowered, and the loss is increased. End up.

As is apparent from the above, when the inter-coil distance L ₁ fluctuates, there is a problem that the power feeding efficiency from the power feeding unit 3 to the power receiving unit 5 fluctuates and the loss increases. Further, as shown in FIG. 8, even when a lateral deviation x in which the axes of the power feeding side loop antenna 6, the power feeding side helical coil 7, the power receiving side loop antenna 10, and the power receiving side helical coil 9 are displaced occurs, There is a problem that the power supply efficiency from 3 to the power receiving unit 5 fluctuates and the loss increases.

JP 2010-124522 A JP 2010-68657 A

  Therefore, the present invention provides a power feeding system that can supply power with high efficiency from the power feeding unit to the power receiving unit even if a variation in the distance between the power feeding side helical coil and the power receiving side helical coil or a lateral shift occurs. This is the issue.

The invention according to claim 1, which has been made in order to solve the above-described problem, includes a power feeding loop antenna to which power is supplied, a power feeding means provided with a power feeding coil that is electromagnetically coupled to the power feeding loop antenna, A power receiving system provided with a power receiving side coil that electromagnetically resonates with the power feeding side coil and a power receiving side loop antenna that is electromagnetically coupled to the power receiving side coil; and at least one of the power feeding side coil and the power receiving side coil A capacitor connected in parallel on one side and a capacitor variably provided , and in the power receiving means, a reflection measuring means for measuring the amount of reflection at the power receiving side coil from the power sent from the power feeding side coil to the power receiving side coil And adjusting means for adjusting the capacitance of the capacitor according to the amount of reflection measured by the reflection measuring means. It resides in the power system.

  As described above, according to the first aspect of the present invention, the capacitor having a variable capacitance is connected in parallel to at least one of the power feeding side coil and the power receiving side coil. Since the efficiency varies when the capacitance of the capacitor is changed, the distance between the power supply side coil and the power reception side coil is changed or changed by changing the capacitance of the capacitor according to the distance and the horizontal displacement of the power supply side coil and the power reception side coil. Even if it occurs, power can be supplied with high efficiency.

According to the first aspect of the present invention, the reflection measurement unit measures the reflection amount of the power receiving coil, and the adjustment unit adjusts the capacitance of the capacitor according to the reflection amount measured by the reflection measurement unit. it can vary and lateral displacement of the coil and the distance of the power receiving coil is adjusted to a volume that can supply the power at automatic high efficiency even if it occurs.

It is a figure which shows the electric power feeding system of this invention in 1st Embodiment. It is a perspective view which shows the structure of the electric power feeding system shown in FIG. The resonance frequency of the power supply side and power reception side helical coils of the power supply system shown in FIG. 1 is fixed at 8.1 MHz, and the power supply side and power reception side varactors are adjusted according to the fluctuation of the inter-coil distance L ₁ between the power supply side and power reception side helical coils. It is a graph which shows the result of having measured the passage characteristic S21 of the receiving side loop antenna when changing a capacity | capacitance. The resonance frequency of the power supply side and power reception side helical coils of the power supply system shown in FIG. 1 is fixed at 8.1 MHz, and the power supply side and power reception side varactors are adjusted according to the fluctuation of the inter-coil distance L ₁ between the power supply side and power reception side helical coils. It is a graph which shows the result of having measured the reflective characteristic S11 of the receiving side loop antenna when changing a capacity | capacitance. The resonance frequency of the power supply side and power reception side helical coils of the power supply system shown in FIG. 1 is fixed at 17 MHz, and the capacities of the power supply side and power reception side varactors are set according to the fluctuation of the inter-coil distance L ₁ between the power supply side and power reception side helical coils. It is a graph which shows the result of having measured the passage characteristic S21 of the receiving side loop antenna when changing it. The resonance frequency of the power supply side and power reception side helical coils of the power supply system shown in FIG. 1 is fixed at 17 MHz, and the capacities of the power supply side and power reception side varactors are set according to the fluctuation of the inter-coil distance L ₁ between the power supply side and power reception side helical coils. It is a graph which shows the result of having measured the reflection characteristic S11 of the receiving side loop antenna when changing. It is a figure which shows the electric power feeding system of this invention in 2nd Embodiment. It is a flowchart for demonstrating the process sequence of the control part which comprises the electric power feeding system shown in FIG. It is explanatory drawing for demonstrating the horizontal shift x. It is a perspective view which shows an example of the conventional electric power feeding system. The power receiving side loop antenna when the inter-coil distance L ₁ is changed in the range of 100 mm to 400 mm with the antenna diameters R ₁₁ and R ₁₂ of the power feeding side and power receiving side loop antennas shown in FIG. It is a graph which shows the result of having measured the passage characteristic S21. The power receiving side loop antenna when the inter-coil distance L ₁ is changed in the range of 100 mm to 400 mm with the antenna diameters R ₁₁ and R ₁₂ of the power feeding side and power receiving side loop antennas shown in FIG. It is a graph which shows the result of having measured the reflection characteristic S11. The power receiving side loop antenna when the inter-coil distance L ₁ is changed in the range of 100 mm to 400 mm with the antenna diameters R ₁₁ and R ₁₂ of the power feeding side and power receiving side loop antennas shown in FIG. It is a Smith chart which shows the result of having measured the reflection characteristic S11.

The first embodiment will be described below with reference power supply system of the present invention with reference to the drawings. FIG. 1 is a diagram showing a power feeding system of the present invention in the first embodiment. FIG. 2 is a perspective view showing a configuration of the power feeding system shown in FIG. As shown in the figure, the power supply system 1 includes a power supply unit 3 as a power supply unit provided on a road 2 and the like, and a power reception unit 5 as a power reception unit provided in an abdomen of an automobile 4 or the like. ing.

  As shown in FIGS. 1 and 2, the power feeding unit 3 includes a power feeding side loop antenna 6 to which power is supplied, a power feeding side helical coil 7 as a power feeding side coil electromagnetically coupled to the power feeding side loop antenna 6, and A power supply side varactor 8 as a capacitor connected in parallel to the power supply side helical coil 7 is provided. The feeding-side loop antenna 6 is provided in a circular loop shape, and is arranged so that its axis is along the direction from the road 2 toward the abdomen of the automobile 4, that is, the vertical direction. The power feeding side loop antenna 6 is supplied with AC power from an AC power source V.

  The power supply side helical coil 7 is configured, for example, by winding a winding in a coil shape having a diameter larger than the diameter of the power supply side loop antenna 6. The feeding-side helical coil 7 is arranged coaxially with the feeding-side loop antenna 6 on the automobile 4 side of the feeding-side loop antenna 6. In the present embodiment, the feeding-side loop antenna 6 is arranged on the same plane as the winding of the feeding-side helical coil 7 that is farthest from the automobile 4.

  As a result, the feeding-side loop antenna 6 and the feeding-side helical coil 7 are within a range where they are electromagnetically coupled to each other, that is, when AC power is supplied to the feeding-side loop antenna 6 and an alternating current flows, They are separated from each other within a range where an induced current is generated. The power supply side varactor 8 is a diode whose capacitance changes according to the voltage applied to both ends.

  The power receiving unit 5 is connected in parallel to a power receiving side helical coil 9 that electromagnetically resonates with the power feeding side helical coil 7, a power receiving side loop antenna 10 that is electromagnetically coupled to the power receiving side helical coil 9, and a power receiving side loop antenna 10. A power receiving side varactor 11 is provided. The power receiving side loop antenna 10 is connected to a load such as an in-vehicle battery (not shown). The power receiving side loop antenna 10 is provided in a loop shape, and its axis is arranged along the direction from the belly portion of the automobile 4 toward the road 2, that is, along the vertical direction.

  The power reception side helical coil 9 is provided in the same manner as the power supply side helical coil 7, and is composed of a coil having a diameter larger than that of the power supply side and the power reception side loop antennas 6 and 10. The power receiving side helical coil 9 is disposed on the road 2 side of the power receiving side loop antenna 10 and coaxially with the power receiving side loop antenna 10. In the present embodiment, the power receiving side loop antenna 10 is arranged on the same plane as the winding on the side farthest from the road 2 of the power receiving side helical coil 9.

  As a result, the power receiving side loop antenna 10 and the power receiving side helical coil 9 are within a range where they are electromagnetically coupled to each other, that is, within a range where an induction current is generated in the power receiving side loop antenna 10 when an alternating current flows through the power receiving side helical coil 9. Are spaced apart from each other.

  According to the power supply system 1 described above, when the automobile 4 approaches the power supply unit 3 and the power supply side helical coil 7 and the power reception side helical coil 9 face each other with an interval in the axial direction, the power supply side helical coil 7 and the power reception system receive power. The side helical coil 9 can electromagnetically resonate to supply power from the power feeding unit 3 to the power receiving unit 5 in a contactless manner.

  More specifically, when AC power is supplied to the power supply side loop antenna 6, the power is sent to the power supply side helical coil 7 by electromagnetic induction. When power is sent to the power supply side helical coil 7, the power is wirelessly sent to the power receiving side helical coil 9 by magnetic field resonance. Further, when power is sent to the power receiving side helical coil 9, the power is sent to the power receiving side loop antenna 10 by electromagnetic induction and supplied to a load connected to the power receiving side loop antenna 10.

Next, the principle of the present invention will be described before the detailed configuration of the power feeding system 1 is described. First, the inventors change the capacities of the power supply side and the power reception side varactors 8 and 11 according to the fluctuation of the inter-coil distance L ₁ between the power supply side helical coil 7 and the power reception side helical coil 9. The transmission characteristic S21 and the reflection characteristic S11 were measured. The results are shown in FIGS. In the measurement of FIGS. 3 and 4, the inter-coil distance L ₁ and the capacities C of the feeding side and receiving side varactors 8 and 11 are set as shown in Table 1 below.

In the measurements shown in FIGS. 3 and 4, the antenna diameters R ₁₁ and R ₁₂ of the power supply side and power reception side loop antennas 6 and 10 are 150 mm, and the power reception side and power supply side helical coils 7 and 9 are 7 turns. Yes.

As shown in the figure, even if the inter-coil distance L ₁ varies, the frequency of the efficiency can be kept constant by changing the capacities of the power supply side and the power reception side varactors 8 and 11. That is, even if the inter-coil distance L ₁ varies, high efficiency can be obtained in the vicinity of the frequency of 8.1 MHz.

In order to investigate whether or not the above characteristics can be obtained even if the resonance frequency changes, the inventors set the number of turns of the helical coils 7 and 9 on the power supply side and the power reception side to 3 and sets the resonance frequency to around 17 MHz, and the distance between the coils. feeding side in accordance with a variation in L _1, were measured pass characteristic S21 and reflection characteristic S11 in a case of varying the power receiving side varactor 8,11. The results are shown in FIGS. 5 and 9, the inter-coil distance L ₁ and the capacities of the power feeding side and power receiving side varactors 8 and 11 are set as shown in Table 2 below.

  In the measurements shown in FIGS. 5 and 6, parameters other than the windings of the power supply side and power reception side helical coils 7 and 9 are the same as those in FIGS. 3 and 4.

As shown in the figure, even when the resonance frequency is 17 MHz, the efficiency and frequency are kept constant by changing the capacities of the power supply side and the power reception side varactors 8 and 11 even if the inter-coil distance L ₁ varies. be able to. That is, even if the inter-coil distance L ₁ varies, high efficiency can be obtained in the vicinity of a frequency of 17 MHz.

Next, returning to the configuration of the power feeding system 1 again, as shown in FIG. 1, the power feeding system 1 is further installed on the road 2 side with a variable voltage source 12 that applies a voltage to both ends of the power feeding varactor 8. The distance measuring unit 13 for measuring the inter-coil distance L ₁ and the variable voltage source 12 so that a voltage corresponding to the inter-coil distance L ₁ measured by the distance measuring unit 13 is applied to the power supply varactor 8. And a control unit 14 as adjusting means for controlling.

The variable voltage source 12 is provided with a variable applied voltage. As the distance measuring unit 13, for example, infrared rays or UWB radio is considered, by measuring the distance from the road 2 to the ventral portion of the car 4, determine the distance between the coils L ₁ from the measured distance. The control unit 14 is constituted by a CPU, for example.

In addition, as shown in FIG. 1, the power supply system 1 further includes a variable voltage source 15 that applies a voltage to both ends of the power receiving side varactor 11, and a voltage corresponding to the inter-coil distance L ₁ measured by the distance measuring unit 13. And a control unit 16 as adjustment means for controlling the variable voltage source 12 so as to be applied to the power supply varactor 8. The variable voltage source 15 is provided with a variable applied voltage. The control unit 16 is constituted by a CPU, for example.

Next, the operation of the above-described power feeding system 1 will be described. First, the control unit 14 takes in the inter-coil distance L ₁ obtained by the distance measurement unit 13. For example, the control unit 14 stores a table indicating the relationship between the inter-coil distance L ₁ and the capacitance C of the power supply varactor 8 as shown in Tables 1 and 2 in a memory (not shown). The control unit 14 reads the capacitance C of the power supply side varactor 8 corresponding to the inter-coil distance L ₁ taken from the table, and controls the variable voltage source 12 so as to become the read capacitance C.

Further, the control unit 14 controls the AC power source V to multiplex a modulation signal such as AM, FM, PM or ASK, FSK, PSK or the like in the magnetic field during power transmission, and the coil obtained by the distance measurement unit 13 is transmitted to the signal. The inter-coil distance L ₁ is incorporated, and the inter-coil distance L ₁ is transmitted to the automobile 4 side. The control unit 16 takes in the inter-coil distance L ₁ from the power transmitted to the power receiving side loop antenna 10. In the control unit 16, a table indicating the relationship between the inter-coil distance L1 and the capacity C of the power receiving varactor 11 as shown in Tables 1 and 2 is described in a memory (not shown). The control unit 16 reads the capacitance C of the power receiving varactor 11 corresponding to the inter-coil distance L ₁ taken from the table, and controls the variable voltage source 15 so as to be the read capacitance C.

According to the power feeding system 1 described above, the power feeding side and the power receiving side varactors 8 and 11 in which the capacitance C is variably provided in both the power feeding side helical coil 7 and the power receiving side helical coil 9 are connected in parallel. Since the efficiency fluctuates when the capacity of the power supply side and the power reception side varactors 8 and 11 is changed, the capacity of the power supply side and the power reception side varactors 8 and 11 depends on the inter-coil distance L ₁ between the power supply side helical coil 7 and the power reception side helical coil 9. Thus, even if the inter-coil distance L ₁ between the power supply side helical coil 7 and the power reception side helical coil 9 varies, it is possible to supply power with high efficiency.

Further, according to the power feeding system 1 described above, the distance measuring unit 13 measures the inter-coil distance L ₁ between the power feeding side helical coil 7 and the power receiving side helical coil 9, and the control units 14 and 16 measure the distance measuring unit 13. the power receiving side in accordance with the distance between the coils L _1, since adjusting the capacitance C of the power feeding side varactor 8 and 11 automatically high inter-coil distance L ₁ of the power feeding side Herukarukoiru 7 and the power receiving side Herukarukoiru 9 be varied The capacity C can be adjusted so that power can be supplied with efficiency. Thus, variations in the distance between the coils L ₁ by the upper and lower suspension of a motor vehicle 4, luggage, can supply power with high efficiency coil distance L ₁ is varied by amount of the occupant.

In the first embodiment described above, the inter-coil distance L ₁ measured by the distance measuring unit 13 is transmitted to the automobile 4 side, but the present invention is not limited to this. For example, it is also possible to transmit the capacitance C of the power receiving side varactor 11 according to the distance between the coils L _1.

  In the first embodiment described above, the feeding side and receiving side varactors 8 and 11 are connected in parallel to both the feeding side helical coil 7 and the receiving side helical coil 9, but the present invention is limited to this. It is not a thing. For example, the power receiving side varactor 11 may be omitted, the power feeding side varactor 8 may be provided in parallel only to the power feeding side helical coil 7, and the capacity of the power feeding side varactor 8 may be adjusted. Alternatively, the power receiving side varactor 8 may be eliminated, the power receiving side varactor 11 may be provided in parallel only to the power receiving side helical coil 9, and the capacity of the power receiving side varactor 11 may be adjusted.

Further, according to the first embodiment described above, the distance measuring section 13 power feeding side based on the distance between the coils L ₁ measured by, had been adjusted power receiving side varactor 8,11, the present invention is limited to this It is not a thing. For example, the control units 14 and 16, the distance measurement unit 13, the power supply side varactor 8, and the variable voltage source 12 are eliminated from FIG. 1. Then, at the manufacturing stage, the variable voltage source 15 is adjusted so that the power receiving side varactor 11 has a value corresponding to the vehicle type, that is, the inter-coil distance L ₁ , and thereafter the power receiving side varactor 11 is not adjusted without adjusting the variable power supply pressure 15. The capacity C may be fixed. In this case as well, even if the inter-coil distance L ₁ differs depending on the vehicle type, power can be fed with high efficiency using the common loop antennas 6 and 10 and the helical coils 7 and 9.

Second Embodiment Next, a second embodiment will be described. In the first embodiment described above, the capacities C of the power supply side and the power reception side varactors 8 and 11 are adjusted according to the inter-coil distance L ₁ measured by the distance measuring unit 13, but in the second embodiment, FIG. As shown in FIG. 5, instead of the distance measuring unit 11, a reflection measuring unit 18 for measuring the amount of reflection of the power receiving side helical coil 9 is provided on the vehicle side, and the power receiving side varactor 8 is eliminated, and only the power receiving side varactor 11 is provided. It can be considered that the control unit 16 adjusts the capacitance C of the power receiving varactor 11 so that the reflection characteristic S21 measured by the reflection measuring unit 18 is improved. The reflection measuring unit 18 described above is a device that measures the power sent to the power-receiving-side helical coil 9 and obtains the amount of reflection from the measured power. For example, a directional coupler or a circulator may be used. .

  Next, detailed operation of the control unit 16 described above will be described with reference to FIG. First, when the control unit 16 detects that the power supply from the power supply unit 3 is started from the power supplied to the power receiving side helical coil 9 measured by the reflection measurement unit 18, the control unit 16 starts capacity adjustment processing. First, the control unit 16 takes in the reflection amount obtained by the reflection measurement unit 18 (step S1), and determines whether or not the reflection amount is equal to or less than a certain amount (step S2). If the amount of reflection is below a certain amount (Y in step S2), the control unit 16 returns to step S1 again. On the other hand, if the amount of reflection exceeds a certain amount (N in step S2), the control unit 16 controls the variable voltage source 15 to increase the capacitance C of the power receiving varactor 11 (step S3).

  Next, the control unit 16 takes in the reflection amount again (step S4), and determines whether or not the reflection amount has decreased as a result of moving in step S3 (step S5). If the amount of reflection has decreased (Y in Step S5), the control unit 16 determines whether or not the amount of reflection has become a certain amount or less as a result of the decrease in the amount of reflection (Step S6). If the amount of reflection is below a certain amount (Y in step S6), the control unit 16 returns to step S1 again.

  On the other hand, if the amount of reflection exceeds a certain amount (N in step S6), the control unit 16 increases the capacity C of the power receiving side varactor 11 again (step S7). Thereafter, the control unit 16 captures the reflection amount again (step S8), and repeats the operation of step S7 until the captured reflection amount becomes a predetermined amount or less. When the amount of reflection captured in step S8 is less than or equal to a certain amount (Y in step S9), the control unit 16 returns to step S1 again.

  On the other hand, if the amount of reflection has not decreased (N in step S5), the control unit 16 conversely decreases the capacitance C of the power receiving side varactor 11 (step S10). Thereafter, the control unit 16 captures the reflection amount again (step S11), and repeats the operation of step S10 until the captured reflection amount becomes equal to or less than a predetermined amount. When the amount of reflection captured in step S11 becomes a certain amount or less (Y in step S12), the control unit 16 returns to step S1 again. According to 2nd Embodiment mentioned above, it can be set as the magnitude | size which can supply electric power with high efficiency automatically.

  In the first embodiment described above, efficiency reduction due to a change in distance is prevented. However, in the second embodiment, since it depends on the amount of reflection, as shown in FIG. It is possible to deal with both fluctuations in the positional deviation x and distance fluctuations between the axis of the helical coil 7 and the axes of the power receiving side loop antenna 10 and the feeding side helical coil 7.

  In addition, according to 2nd Embodiment mentioned above, although the electric power feeding side varactor 8 was lose | eliminated, this invention is not limited to this. For example, in a system in which the automobile 4 and the road 2 can communicate with each other, the control unit 16 transmits an adjustment command by communication to the road 2 side without losing the power supply side varactor 8, and the power supply side varactor 8. The capacity C of the power receiving side varactor 11 may be adjusted.

  Further, according to the above-described embodiment, the varactor is used as the capacitor, but the present invention is not limited to this. For example, a variable condenser that adjusts the capacity by a mechanical operation may be used.

  Further, the above-described embodiments are merely representative forms of the present invention, and the present invention is not limited to the embodiments. That is, various modifications can be made without departing from the scope of the present invention.

1 Power Supply System 3 Power Supply Unit (Power Supply Means)
5 Power receiving unit (power receiving means)
6 Feed-side loop antenna 7 Feed-side helical coil 8 Feed-side varactor (capacitor)
11 Power receiving varactor (capacitor)
13 Distance measuring unit (distance measuring means)
14 Control unit (adjustment means)
16 Control unit (adjustment means)
18 Reflection measurement unit (reflection measurement means)

Claims (1)

A power feeding means provided with a power feeding side loop antenna to which power is supplied, a power feeding side coil electromagnetically coupled to the power feeding side loop antenna, a power receiving side coil that electromagnetically resonates with the power feeding side coil, and an electromagnetic coupling to the power receiving side coil A power receiving system provided with a power receiving side loop antenna,
A capacitor variably provided in a capacitance connected in parallel to at least one of the power feeding coil and the power receiving coil;
In the power receiving means, reflection measurement means for measuring the amount of reflection at the power receiving side coil from the power sent from the power feeding side coil to the power receiving side coil;
Adjusting means for adjusting the capacitance of the capacitor according to the amount of reflection measured by the reflection measuring means;
A power supply system comprising:

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