JP5777139B2 - Vehicle power supply apparatus and vehicle power supply method - Google Patents

Description

  The present invention relates to a power feeding device and a power feeding method from a road surface for a vehicle using electric energy as power.

  The non-contact power transmission system is roughly classified into the following two systems. The first is power transmission by non-radiation, and the second is power transmission by radiation. The first method mainly includes an electromagnetic induction method using a frequency of several kHz or less using the principle of a transformer and a near field (static energy accumulated in the near field) using a frequency of about several tens of MHz. There is an electromagnetic coupling method using electromagnetic resonance. The second method includes a method using microwave power transmission and a method using laser power transmission.

  As electric power transmission using an electromagnetic induction method, techniques of Patent Documents 1 and 2 below are known. The technique of Patent Document 1 discloses a device that transmits power in a non-contact manner using a pair of power coils of a power transmission coil and a power reception coil separated by 5 to 10 mm for power transmission from a fixed part to a rotating part. Yes. According to the document, a frequency power of several hundred kHz is transmitted from the fixed unit to the rotating unit, and the detection signals of various sensors installed in the rotating unit are transmitted by a pair of data coils provided outside the power coil. The signal is transmitted with a signal of several MHz from to the fixed part. Moreover, since the input impedance of the power transmission coil of the fixed portion changes depending on the distance between the power transmission coil and the power reception coil, the frequency of the power supplied to the power transmission coil can be changed in order to improve the power feeding efficiency to the power transmission coil. Has been done.

  As an electromagnetic coupling method based on electromagnetic resonance, a technique disclosed in the following Non-Patent Document 1 that has recently attracted attention is known. The technique of Non-Patent Document 1 discloses a technique capable of transmitting 9.9 MHz sine wave power using a pair of strongly electromagnetically coupled electromagnetic resonance coils having a radius of 25 cm and spaced apart by about 2 m. .

  These power supply methods supply power when the vehicle is stopped. As a power feeding method when the vehicle is traveling, a technique disclosed in Patent Document 2 below is known. In this technique, a primary coil is embedded in a road surface, a secondary coil is provided at the bottom of a vehicle body so as to face the primary coil, and power is supplied from the primary coil to the secondary coil by electromagnetic induction.

JP-A-8-340285 JP-A-7-39007

Wireless Power Transfer via Strongly Coupled Magnetic Resonances, Andre Kurs, et.al, Science Vol.317, 6 July 2007 Takashi Ohira, "Circuit Exercises for Matrix: Thinking Analog Circuits with Paper and Pencil [I] Port Parameters of Analog Circuits", Journal of IEICE, Vol.93, No.1, pp. 67-72, 2010 January.

  The method disclosed in Patent Document 1 is a method in which a resonance circuit is provided outside the coil, and the Q value is small, so that efficient power transmission cannot be performed. Since this method is essentially an electromagnetic induction method, in principle, it is a technique for increasing the coupling coefficient, and the distance between the two coils must be narrowed to about 5 to 10 mm. In addition, there is a problem that the transmission efficiency has to be low. Further, when the distance is 10 mm or more, not only efficient transmission is possible, but also the input impedance of the power transmission coil changes, so that the power transmission frequency needs to be adjusted. In these power transmission systems, since an external resonance circuit is used, the resonance characteristics are unimodal characteristics.

  On the other hand, the technique disclosed in Non-Patent Document 1 of the electromagnetic resonance method is, in principle, a method using electromagnetic resonance using near-field energy as a whole using a resonance type coil and a power transmission coil and a power reception coil. In principle, this is a wireless power transmission system that has a high Q value, can be transmitted over a relatively long distance, has no radiation loss, and has high transmission efficiency. In addition, due to the use of electromagnetic resonance, high transmission efficiency can be achieved even if the coupling coefficient is small (in principle, even in a state close to 0) if the frequency, the Q value of the power transmission coil and the power reception coil are large. Can do. As a result, according to Non-Patent Document 1, a transmission efficiency of 90% or more can be realized even if both power coils are separated by about 1 m. The frequency characteristic of this resonance shows a bimodal characteristic.

  However, when transmitting a large amount of power using the technique of Non-Patent Document 1, if the distance between the power transmission coil and the power reception coil changes, the two resonance frequencies that increase the transmission efficiency change, and the frequency of the transmission power is changed. Even when the optimum frequency is set for the transmission efficiency, if the distance between the two coils is increased, the transmission efficiency is lowered.

In addition, with the above method, power cannot be supplied to the traveling vehicle. On the other hand, the method of Patent Document 2 is a method in which a primary coil and a secondary coil are magnetically coupled to supply power from a primary coil embedded in a road surface to a secondary coil installed in a vehicle body. In this document, the unevenness of the road surface is detected, and the distance between the secondary coil and the primary coil is controlled. Since the height of the secondary coil with respect to the road surface is controlled during traveling, the control is complicated and not practical. Moreover, in the method using the coupling between the coils in all the above-mentioned documents, there is a problem that the transmission efficiency is lowered when the distance between the coils is increased.
In any of the above-described techniques, efficient power transmission cannot be realized unless the two coils are close to each other and the distance between the coils is kept constant. Further, it is necessary to align the two coils, and it is necessary to accurately position the parking position of the vehicle during power feeding.

The present invention has been made to solve these problems, and aims to enable efficient power feeding to a vehicle even if the distance between one power feeding electrode and the other power receiving electrode is large. To do.
It is another object of the present invention to stabilize the impedance between the power feeding electrode and the power receiving electrode even when the distance between the one power feeding electrode and the other power receiving electrode is large and to enable stable power feeding to the vehicle with high efficiency.
Another object of the parking power supply is to achieve highly efficient power supply without accurately positioning the vehicle.
Another object of the present invention is to enable stable power feeding from the road surface to the vehicle even when the vehicle is traveling.
The present invention relates to a vehicle power supply apparatus and a vehicle power supply method for supplying power from a road surface to a vehicle body via a tire of the vehicle, and no prior art relating to power supply from the road surface to the vehicle body via a tire is known at all. .

In the first tire, the first tire includes a first conductor installed below the first tire of the vehicle and a second conductor installed below the second tire of the vehicle. through the conductor and the second tire inner conductors with the second tire, a vehicle power supply device that supplies power to the vehicle, close to the first tire, attached inner conductor capacitively first tire, is arranged on the vehicle AC power that is supplied between the first electrode and the second conductor, in close proximity to the first electrode and the second tire, capacitively coupled to the second tire conductor, and fed between the first electrode and the second conductor. The vehicle power supply device includes a power receiving device that receives power from the first electrode and the second electrode.

  In the present invention, attention is paid to the fact that a tire has a capacitance, and AC transmission from the road surface to the vehicle body is realized by using the capacitance. In a tire having a steel belt inside, a steel belt made of a ribbon-like metal mesh is provided along the outer periphery of the tire in a tread rubber that hits a ground contact portion with respect to a road surface. Therefore, since the distance between the outer peripheral surface of the tire and the steel belt is small and the area of the steel belt is large, there is a large capacitance between the outer peripheral surface of the tire and the steel belt. Furthermore, the tire has a metallic cylindrical rim on which tire rubber is mounted, and a metallic disk extending in the radial direction connected from the shaft to the outer periphery of the rim. The distance between the tire surface and the rim or disk is short, and the area of the rim or disk is large. Accordingly, there is a large capacitance between the tire surface and these rims and disks. That is, a cylindrical capacitor is formed between the outer peripheral surface of the tire and a concentric cylindrical metal body. This is because if two conductors are provided close to the outer peripheral surface of the tire (including contact) at different positions in the rotation angle direction, the static distance between the two conductors is large even if the distance between the two conductors is large. The capacitance is large, and a capacitor having a large capacitance using two conductors as electrodes is formed. For example, when two conductors are provided at opposite positions in the diameter direction of the tire, the distance between the two conductors is separated by the diameter of the tire, but the capacitance between the two conductors is large. AC power can be transmitted from one conductor to the other using the capacitance of the tire. This is the principle of the present invention.

  The first conductor and the second conductor may be disposed on the road surface or embedded under the road surface. The road surface means a surface that comes into contact with a tire, such as a road surface of a general road, a road surface of a parking lot, a floor surface of a garage, a surface where a vehicle passes through, such as a car stop. The first tire and the second tire are respectively positioned in contact with the first conductor and the second conductor or with asphalt, concrete, and a plate interposed therebetween. The first conductor and the second conductor may be a flat planar conductor or a flat mesh conductor. In the case of a mesh conductor, the mesh is sufficiently shorter than the wavelength of the operating frequency. Similarly, the first electrode and the second electrode are a flat planar conductor, a cylindrical roller conductor, a ring-shaped conductor provided on the outer peripheral surface of the rubber roller, an arc-shaped strip-shaped conductor along the outer peripheral surface of the tire, It may be a semi-cylindrical conductor concentric with the outer peripheral surface. The first electrode and the second electrode may be attached to the tire cover (hood) so as to face the outer peripheral surface of the tire. The conductors of the first electrode and the second electrode may be mesh conductors. In the case of a mesh conductor, the mesh is sufficiently shorter than the wavelength of the operating frequency. The first electrode and the second electrode are provided close to the first tire and the second tire, respectively. In the present invention, proximity is a concept including contact with a tire. For example, the first electrode and the second electrode are in contact with the outer peripheral surfaces of the first tire and the second tire, respectively, or are provided at a certain distance from the outer peripheral surface, It may be provided close to the axle (including contact). A plurality of first electrodes and second electrodes may be provided at a plurality of positions close to the first tire and the second tire, respectively. Since the electrode placed at the position where the capacity becomes the largest contributes to the transmission of the AC power, it is possible to prevent the deterioration of the transmission characteristics with respect to the electrode arrangement position.

The reason for using the first tire and the second tire is to provide a path for supplying current from the road surface and a path for returning to the road surface. Accordingly, two or more tires may be used as long as a current supply path from the road surface via the tire to the vehicle and a return path from the vehicle to the road surface via the tire are formed. For example, the first and third tires may be used in parallel in the current supply path, and the second and fourth tires may be used in parallel in the current return path. Alternatively, only the first tire may be used in the current supply path, and the second and fourth tires may be used in parallel in the current return path. Conversely, the first and third tires may be used in parallel in the current supply path, and only the second tire may be used in the current return path. The vehicle means a moving body having tires, and includes an automobile, a motorcycle, a bicycle, a radio control car, an industrial vehicle, a robot, and the like.

  The power receiving device is a circuit including a rectifier circuit that rectifies AC power, a battery that stores rectified power, and the like. The power receiving device includes a capacitance between the first conductor and the first tire inner conductor, a capacitance between the first electrode and the first tire inner conductor, a capacitance between the second conductor and the second tire inner conductor, and the second electrode and the second. In a circuit including a capacitance between tire inner conductors, it is desirable to have a coil that causes resonance. A coil may be inserted in series with respect to the capacity of the tire to cause series resonance, or a coil may be inserted in parallel with respect to the capacity to cause parallel resonance. Further, resonance may be realized by a distributed constant circuit. It is desirable to provide a matching circuit for matching impedance.

  The present invention can be a device that supplies power while traveling, or a power supply device that supplies power when the vehicle is stopped in a parking lot or a garage. That is, when power is supplied during traveling, the first conductor and the second conductor are installed on the road surface on which the first tire and the second tire are traveling, or are buried under the road surface. What is necessary is just to provide the 1st conductor and the 2nd conductor with the width | variety and space | interval which a tire of both sides can drive | work in a driving lane. In standard stable driving, power is supplied from the road surface and power is stored in the battery, so that driving continues even if the tires deviate from the power supply track for a period of time due to intersections or lane changes. It is possible to do. Moreover, even if the tire rotates, the electrostatic capacity with the first tire and the second tire interposed between the first conductor, the second conductor, the first electrode, and the second electrode does not change. Therefore, even when the vehicle is traveling, stable power feeding from the road surface is possible.

  Further, if power is supplied when the vehicle is stopped in a parking lot or the like, the first conductor and the second conductor are installed on the road surface where the first tire and the second tire are in contact with each other at the time of parking, or the road surface Buried underneath. Or you may provide a 1st conductor and a 2nd conductor in the surface and inside of a wheel stopper.

  According to a second aspect of the present invention, in the power supply device for a vehicle, the first conductor installed below the first tire of the vehicle, the second conductor installed below the second tire of the vehicle, and the first tire Proximity coupling with the first tire inner conductor of the first tire in proximity, capacitive coupling with the first electrode disposed in the vehicle and the second tire inner conductor of the second tire in proximity to the second tire And a second electrode disposed in the vehicle, and a power receiving device that receives AC power fed between the first conductor and the second conductor by the first electrode and the second electrode. It is a vehicle electric power feeder.

In this invention, the power receiving device includes a capacity between the first conductor and the first tire inner conductor, a capacity between the first electrode and the first tire inner conductor, a capacity between the second conductor and the second tire inner conductor, and a second capacity. In the circuit including the capacitance between the electrode and the second tire inner conductor, it is desirable to have a coil that causes resonance. A coil may be inserted in series with respect to the capacity of the tire to cause series resonance, or a coil may be inserted in parallel with respect to the capacity to cause parallel resonance. Further, resonance may be realized by a distributed constant circuit. In addition, it is desirable to have a matching circuit for matching the impedance so that the left and right impedances viewed from the first electrode and the second electrode are equal.
Moreover, in this invention, you may have a power supply device which supplies alternating current power between a 1st conductor and a 2nd conductor.
Further, the power supply device includes a capacity between the first conductor and the first tire inner conductor, a capacity between the first electrode and the first tire inner conductor, a capacity between the second conductor and the second tire inner conductor and the second electrode. It is desirable to have a coil that causes resonance in the circuit including the capacitance between the first tire inner conductor and the second tire inner conductor. In addition, it is desirable to have a matching circuit for matching impedances so that the impedances seen from the left and right from the first conductor and the second conductor are equal.

Moreover, in the electric power feeding method with respect to a vehicle, it can be set as the vehicle electric power feeding method which feeds alternating current power to a vehicle from a road surface by capacitive coupling, using the tire which a vehicle has as capacity | capacitance .
Chi words, according to the principle noted above, by utilizing an electrostatic capacitance of the tire, a vehicle power supply method for supplying power toward the vehicle body from the road surface. In this case, a method may be considered in which a tire is provided in the current supply path, and a metal body is brought close to (including contact with) the road surface directly without providing a tire in the current return path. In short, it is only necessary to supply power to the vehicle body by interposing a tire on one path.

According to a third aspect of the present invention, in the power feeding method for the vehicle, the first conductor is installed on the road surface in contact with the first tire of the vehicle, or on the road surface in contact with the second tire of the vehicle. A second conductor is installed under the road surface, close to the first tire, a first electrode capacitively coupled to the first tire conductor of the first tire is disposed on the vehicle, close to the second tire, A second electrode capacitively coupled to the second tire inner conductor of the tire is disposed on the vehicle, AC power is supplied between the first conductor and the second conductor, and AC power is received by the first electrode and the second electrode. It is the vehicle electric power feeding method characterized by doing.
This invention is invention of the electric power feeding method corresponding to the vehicle electric power feeder of 2nd invention.

In this invention, the capacity between the first conductor and the first electrode (capacity between the first conductor and the first in-tire conductor and the capacity between the first electrode and the first in-tire conductor), between the second conductor and the second electrode In a circuit including the above-described capacitance (capacity between the second conductor and the second tire inner conductor and capacitance between the second electrode and the second tire inner conductor), a coil may be used to resonate and feed power. This coil may be provided in a circuit on the first conductor and second conductor side or in a circuit on the first electrode and second electrode side. The coil may be inserted in series with the capacitor to cause series resonance, or may be inserted in parallel with the capacitor to cause parallel resonance. Moreover, you may provide a coil in both. Further, a matching circuit that equalizes the left and right impedances viewed from the first conductor and the second conductor, and a matching circuit that equalizes the left and right impedances viewed from the first electrode and the second electrode may be provided, respectively.
In the present invention, power supply to the vehicle may be performed when the vehicle is traveling on the road surface.
The in-tire conductor is a concept including a rim, a disk, and a wheel in addition to a steel belt.

  According to the vehicle power supply device and the vehicle power supply method of the present invention, the first conductor, the second conductor provided on the road surface side, and the vehicle side using the capacitance of the tire with the inner conductor of the tire interposed therebetween. Power transmission is performed between the first electrode and the second electrode provided. Therefore, since it is electric power transmission which interposes a tire, efficient electric power transmission is realizable even if the distance between the 1st conductor or the 2nd conductor, and the 1st electrode or the 2nd electrode is long. Moreover, since it is only necessary to position the first tire and the second tire above the first conductor and the second conductor, positioning of the vehicle for power feeding becomes easy. Moreover, if the linear first conductor and the second conductor are installed along the lane of the traveling road, the tires on both sides are passed over the first conductor and the second conductor, so that the traveling power feeding with high efficiency is achieved. Is possible.

BRIEF DESCRIPTION OF THE DRAWINGS The block diagram which showed the whole structure of the vehicle electric power feeder which concerns on the specific Example 1 of this invention. FIG. 2 is an equivalent circuit of the vehicle power supply device according to the first embodiment. The axial sectional view of a tire. The frequency characteristics of the real part of the measured impedance of the tire. Frequency characteristics of the imaginary part of the measured impedance of the tire. The frequency characteristic of the absolute value of the measured impedance of the tire. The frequency characteristics of the measured impedance phase of the tire. Frequency characteristics showing the relationship between the absolute value of the measured impedance between a conductor and an electrode without the tire and the absolute value of the measured impedance of the tire. A circuit for measuring transmission characteristics between a conductor and an electrode with a tire interposed. Smith chart showing transmission characteristics from port 1 to port 2. Transmission characteristics between conductor and electrode with tire interposed. 1 is a circuit diagram of a vehicle power supply device according to Embodiment 1. FIG. The transmission characteristic of the vehicle electric power feeder in FIG. The block diagram which showed the relationship between the tire of the vehicle electric power feeder which concerns on Example 2, and an electrode. The block diagram which showed the relationship between the tire of the vehicle electric power feeder which concerns on Example 3, and an electrode. FIG. 6 is a configuration diagram illustrating a vehicle power feeding method according to a fourth embodiment. FIG. 9 is a configuration diagram illustrating a vehicle power feeding method according to a fifth embodiment. FIG. 10 is a circuit diagram using symmetry of a vehicle power feeding method according to a fifth embodiment. FIG. 10 is an equivalent circuit diagram for explaining the operation of the fifth embodiment.

  Hereinafter, specific examples of the present invention will be described with reference to the drawings. However, the present invention is not limited to the examples.

  FIG. 1 shows the overall configuration of the first embodiment. Two tires are selected from among the tires of the vehicle for power supply. For example, the first tire 11 for the right rear wheel and the second tire 12 for the left rear wheel are selected, contact the first tire 11, and the first conductor 21 is provided below the first tire 11. The second conductor 22 is provided below the first conductor 22. The first conductor 21 and the second conductor 22 are provided on the road surface of the parking lot. A power supply device 30 for supplying power to the vehicle is provided between the first conductor 21 and the second conductor 22. The power supply device 30 includes a signal generator 31, an amplifier 32 that amplifies a signal generated by the signal generator 31 and outputs AC power, and a coil 33. The upper part of the outer periphery of the first tire 11 faces the outer periphery, and the flat plate-like first electrode 41 that does not contact the first tire 11 and the upper part of the outer periphery of the second tire 12 face the outer periphery. As described above, the flat second electrode 42 that is not in contact with the second tire 12 is provided. The first electrode 41 and the second electrode 42 are attached to the vehicle body. For example, a flat electrode may be provided at the tip of a rod protruding from the tire hood toward the outer peripheral surface of the tire. Alternatively, a flat electrode may be provided on the inner surface of the hood of the tire so as to face the outer periphery of the tire. The first electrode 41 and the second electrode 42 are connected to a rectifier circuit 43, and the rectifier circuit 43 is connected to a battery 44. The vehicle power receiving device 40 includes a rectifier circuit 43 and a battery 44.

  In the structure of FIG. 1, an equivalent electric circuit is as shown in FIG. The AC signal having a frequency of 1 MHz generated by the signal generator 31 is amplified by the amplifier 32 to generate AC power S1. The AC power S1 is supplied to the first conductor 21.

  In the present embodiment, the first tire 11 and the second tire 12 are composed of tires having steel belts (in-tire conductors) inside. As shown in the cross-sectional view perpendicular to the axis of the tire in FIG. 3, in a tire having a steel belt inside, a steel belt 13 made of a ribbon-like metal mesh is placed in a tread rubber that hits a ground contact portion with respect to a road surface. Is provided along the outer periphery of the tire. Accordingly, since the distance between the outer peripheral surface 15 of the first tire 11 and the steel belt 13 is small and the area of the steel belt is large, there is a large static space between the outer peripheral surface 15 of the first tire 11 and the steel belt 13. Electric capacity exists. That is, a cylindrical capacitor is formed between the outer peripheral surface 15 of the first tire 11 and the concentric cylindrical steel belt 13.

  Due to the structure of the tire, a large capacitance C1 is formed between the first conductor 21 and the steel belt 13, and a large capacitance C2 is formed between the first electrode 41 and the steel belt 13. As a result, a capacitor C is formed between the first conductor 21 and the first electrode 41 by serial connection of the capacitor C1 and the capacitor C2. As described above, the first conductor 21 and the first electrode 41 form a capacitance using the first tire 11 as a medium. Since the steel tire 13 made of a metal mesh is embedded in the rubber material, the first tire 11 is stable regardless of the angular position of the first electrode 41 on the circumference of the first tire 11. A capacitance C is formed. This means that if two conductors are provided close to the outer peripheral surface of the first tire 11 (including contact) and at different positions in the rotation angle direction, the two conductors can be separated even if the distance between the two conductors is large. The capacitance between them is large, and a capacitor having a large capacitance using two conductors as electrodes is formed. For example, when two conductors are provided at opposite positions in the diameter direction of the tire, the distance between the two conductors is separated by the diameter of the tire, but the capacitance between the two conductors is large. AC power can be transmitted from the first conductor 21 to the first electrode 41 using the electrostatic capacity of the first tire. The same applies to the second tire 12, and the second conductor 22 and the second electrode 42 form a large electrostatic capacity using the second tire 12 as a medium.

  The AC power S <b> 1 supplied from the first conductor 21 is transmitted to the first electrode 41 by the capacity of the first tire 11 and is input to the rectifier circuit 43. Further, the feedback current is induced from the second electrode 42 to the second conductor 22 by the capacity of the second tire 12 and flows to the ground via the coil 33. The inductance of the coil 33 is set to a value that makes series resonance with the capacity C of the first tire 11 and the capacity C of the second tire 12 at a frequency of 1 MHz of the alternating current. In the present invention, AC power is supplied between the first conductor 21 and the second conductor 22, and the first tire 11 and the second tire 12 are used as capacities. Is a device for transmitting AC power.

  Next, the frequency characteristics of the impedance between the first conductor 21 and the first electrode 41 were measured by changing the distance between the first electrode 41 and the outer peripheral upper surface of the first tire 11 in the arrangement relationship of FIG. FIG. A is the real part of the impedance, FIG. B represents the imaginary part of the impedance. In addition, FIG. A is the absolute value of impedance, FIG. B represents the phase of the impedance. When the first electrode 41 is in contact with the first tire 11, the absolute value of the impedance is reduced to about 1/3 at a frequency of 1 MHz as compared with the case where the first electrode 41 is separated, and the advance phase is 1 / It can be seen that it is about 10 smaller. However, it can be seen that even if the first electrode 41 is separated from the outer peripheral surface of the first tire 11 within a range of 1 cm to 4 cm, neither the absolute value nor the phase changes significantly.

  Next, it was confirmed that these characteristics were caused by the presence of the first tire 11 between the first electrode 41 and the first conductor 21. The first tire 11 was removed, the distance between the first electrode 41 and the first conductor 21 was made shorter than the diameter of the first tire 11, and the impedance between the first electrode 41 and the first conductor 21 was measured. . The result is shown in FIG. That is, it can be seen that the impedance between the first electrode 41 and the first conductor 21 is reduced to 1/10 when the first tire 11 is present, compared to when the first tire 11 is not present. Therefore, it can be seen that the presence of the first tire 11 contributes to the transmission of high-frequency power from the first conductor 21 to the first electrode 41.

  Next, the transmission characteristic from the 1st conductor 21 to the 1st electrode 41 was measured in the state where the 1st electrode 41 was made to contact the upper part of the 1st tire. The impedance between the first conductor 21 and the first electrode 41 in a state where the first electrode 41 is in contact with the upper outer peripheral surface of the first tire is about 700-j about 2000Ω at 1 MHz. The resistance component is about 1/3 smaller than the capacitance component. The measurement circuit was the circuit of FIG. The characteristic impedance of the power supply system connected to the port 1 and the measuring instrument connected to the port 2 is set to 50Ω, and in order to match the impedance, between the first conductor 21 and the port 1, the first electrode 41 and the port 2 and T-shaped low-pass filters, respectively. FIG. A is a Smith chart showing the transmission coefficient from port 1 to port 2 and the reflection coefficient from port 1 to port 1, FIG. B shows the transmission characteristics by the simulation from port 1 to port 2 and the reflection coefficient from port 1 to port 1. FIG. As understood from B, in the state where the first tire 11 is present between the first conductor 21 and the first electrode 41, the transmission loss between the first conductor 21 and the first electrode 41 is approximately at a frequency of 1 MHz. It turns out that it is zero.

  FIG. 9 is a circuit diagram in which a first matching circuit 34 is provided between the amplifier 32 and the first conductor 21, and a second matching circuit 45 is provided between the first electrode 41 and the rectifier circuit 43. The first matching circuit 34 is a part of the power supply device 30, and the second matching circuit 45 is a part of the power receiving device 40. Further, the inductance 35 of the first matching circuit 34 is a capacitance C between the first conductor 21 and the first electrode 41 (capacitance C1 between the first conductor 21 and the first in-tire conductor C1 and This corresponds to a coil that causes resonance in a circuit including the capacitance C2) between the first electrode 41 and the first in-tire conductor. Further, the inductance 46 of the second matching circuit 45 corresponds to a coil that is provided in the power receiving device 40 and causes resonance in a circuit including the capacitance C between the first conductor 21 and the first electrode 41.

  FIG. 10 shows transmission characteristics between the ports 1 and 2 (four-terminal network) in the circuit of FIG. It can be seen that the loss is sufficiently small at a frequency of 1 MHz. This seems to be because the resistance component of the tire impedance is sufficiently smaller than the capacitance component. Further, the transmission characteristics when the resistance component of the tire impedance is changed by ± 10% with respect to the above-mentioned value 700Ω are almost the same as the characteristics of FIG. 10, and a characteristic with sufficiently small loss is obtained at a frequency of 1 MHz. It was. Further, the transmission characteristics when the capacitive reactance component of the tire impedance is changed ± 10% with respect to the above value of 2000Ω are almost the same as the characteristics of FIG. 10, and the loss is sufficiently small at a frequency of 1 MHz. was gotten. Therefore, even if there is a change in the tire type, tire deformation during driving, or changes in the external environment such as rain or snow, this vehicle power supply device can stably supply power to the vehicle with high efficiency. it can.

  The first matching circuit 34 and the second matching circuit 45 are configured by T-shaped L and C circuits, but may be configured by π-type C-LC circuits.

  As shown in FIG. 11, the first electrode 41 is composed of a first roller 51 that is in rotational contact with the outer peripheral surface of the first tire 11. Other configurations are the same as those in the first embodiment. According to this configuration, the first electrode and the second electrode can be brought into contact with the outer peripheral surfaces of the first tire and the second tire, and the capacitance C2 between the first electrode and the first tire inner conductor can be increased. Therefore, the capacitance C between the first conductor and the first electrode can be increased. Similarly, the capacitance C2 between the second electrode and the second in-tire conductor can be increased, the capacitance C between the second conductor and the second electrode can be increased, and highly efficient AC transmission is possible. .

The tire rim is configured as shown in FIG. It has a metallic cylindrical rim 61 on which tire rubber is mounted, and a metallic disk 62 extending in the radial direction connected from the shaft 63 to the outer periphery of the rim 61. The distance between the outer peripheral surface of the rim 61 as these conductors and the outer peripheral tip of the disk 62 and the road surface is small, and the area facing the road surface is large. Therefore, a large capacity is formed between the first conductor, the second conductor, the rim 61, and the disk 62, and between the first electrode, the second electrode, the rim 61, and the disk 62. Even through this capacity, AC power can be efficiently transmitted from the first conductor and the second conductor to the first electrode and the second electrode. The rim (wheel) 61 and the disk 62 correspond to the in-tire conductor.
In this case, the first electrode 53 may be provided close to the disk 62. Further, the first electrode 55 may be provided close to the disk 64 to which the first tire 11 is attached. Further, the first electrode 57 may be provided close to the axle 63. The same applies to the second electrode. The other configuration of the vehicle power feeding device is the same as that of the first embodiment.

  As shown in FIG. 13, the present embodiment is an embodiment in which power is supplied to the vehicle from the road surface while the vehicle 75 is traveling. A first conductor 71 and a second conductor 72 are buried below the road surface in one traveling lane 70 of the road. The first conductor 71 and the second conductor 72 are formed in a plate shape along the lane 70. AC power is supplied between the two first conductors 71 and the second conductor 72 from a power supply device (not shown). On the road, a power feeding section is defined, divided into a number of sections, the first conductor 71 and the second conductor 72 are separated for each section, a power feeding device is installed in each section, and power is fed for each section. You may make it do. The widths of the first conductor 71 and the second conductor 72 are formed to be about five times the width of the first tire 11 and the second tire 22. Thereby, even if the position of the vehicle 75 traveling in the lane 70 varies in the width direction of the lane, the first tire 11 and the second tire 12 are positioned on the first conductor 71 and the second conductor 72. can do. Further, the capacity does not change even when the tire rotates. As a result, power can be supplied to the vehicle 75 stably and with high efficiency even during traveling. This electric power can be used as the driving power of the vehicle.

In this embodiment, the steel belt 13 (FIG. 3) and the rim (wheel) 61 of the first tire 11 are electrically connected to receive power from the shaft 63 (FIG. 12). The second tire 12 has the same configuration. The overall configuration is shown in FIG. The first tire 11 is located on the first conductor 21, and the second tire 12 is located on the second conductor 22. AC power supplied between the first conductor 21 and the second conductor 22 is received from both ends of the shaft 631 of the first tire 11 and the shaft 632 of the second tire 12. A capacitor C ₁ is inserted between the first conductor 21 and the second conductor 22, and a capacitor C ₂ is inserted between the shaft 631 and the shaft 632. An inductance 35 is disposed between the signal generator 31 and the first conductor 21. r _s is an equivalent resistance. The inductance 46 is provided between the shaft 631 and the rectifier circuit 43.

Since the structure of the vehicle is symmetrical, the supplied voltage is also a differential mode that is symmetrical. Therefore, if a symmetry plane is taken on the center line, the differential mode voltage is zero volts on the center line due to the mirror image principle. Therefore, it may be considered as a virtual ground point. In conclusion, the circuit of FIG. 14 is equivalent to the circuit of FIG. Note that the parallel capacitance is doubled and the series resistance and inductor are halved. This is represented by an electrical equivalent circuit as shown in FIG. In order to make the mathematical formulas easier to see, symbols without subscripts are used as variable symbols indicating inductor, capacitance, and resistance as shown in FIG. The purpose of this embodiment is to increase the power transmission efficiency of the LCRCL portion in FIG. If L and C are not inserted and only the tire resistance R is used, it is clear that the power transmission efficiency is low. This is because the electrical resistance R of the tire is usually much higher than the internal power supply impedance and load resistance (both are described as z ₀ here).

The operation of the circuit of FIG. 16 will be described below. An actual tire has a complex impedance, but here, for simplicity, this will be described using a pure resistance R as a representative. A coil L is inserted in series on the road side, and a capacitor C is provided in parallel with ground at the output. On the vehicle side, C and L are provided in the reverse order. These L and C values are set to the same values as on the road side. The connection destination of the C ground terminal on the vehicle side will be described later. Let f be the frequency of the AC power supply and write ω = 2πf. Set the output impedance of the AC power supply to the same value as the input impedance of the vehicle load. This is written as z ₀ . Usually, the electrical resistance R of the tire is much higher than z _0.

であることが本実施例の適用条件である。また、本実施例はL とC の値を

と設定し、かつ、コイルのリアクタンス値をタイヤ抵抗より十分大きく

と設定することを特徴とする。 That is,

That is the application condition of this embodiment. In this example, the values of L and C are

And the reactance value of the coil is sufficiently larger than the tire resistance.

It is characterized by setting.

である。この両側に並列にC を設けることにより、そのアドミタンス行列は

となる。
また、この回路のインピーダンス行列は、上記の逆行列、すなわち

である。さらに、この回路の両側にL を直列に挿入すると、そのインピーダンス行列Z は

となる。これを行列の成分毎に分解して書くと、対角成分は

である。 The operation principle will be described below. The admittance matrix of the circuit consisting only of the resistance R of the tire portion is calculated by the calculation method described in Non-Patent Document 2.

It is. By providing C in parallel on both sides, the admittance matrix is

It becomes.
The impedance matrix of this circuit is the above inverse matrix, that is,

It is. Furthermore, when L is inserted in series on both sides of this circuit, its impedance matrix Z becomes

It becomes. When this is broken down into each matrix component and written, the diagonal component is

It is.

となる。同様に、非対角成分は

である。すなわち

かつ

である。 Applying equation (2) to this and erasing L

It becomes. Similarly, the off-diagonal component is

It is. Ie

And

It is.

を得る。この散乱行列から非対角成分だけ抽出すると

となる。これより、電力透過係数｜S₂₁｜² は

となる。 Substituting these results into a formula (Non-patent Document 2) that converts an impedance matrix into a scattering matrix

Get. Extracting only off-diagonal components from this scattering matrix

It becomes. Than this, the power transmission coefficient | S ₂₁ | ² is

It becomes.

である。条件式(1)(3)すなわちz₀ <<R <<ωL を考慮すると、上式の分母の初項と末項は中間項に比べてより高次の微小量なので、近似式として

を得る。
例えば数値例として、タイヤ部分を透過する電力透過効率96% 以上、つまり｜S₂₁｜² > 0.96とするには

すなわち

と設定すればよい。 This can also be expressed in L instead of C using equation (2). That means

It is. Considering conditional expressions (1) and (3), that is, z ₀ << R << ωL, the first and last terms of the denominator in the above expression are higher-order minute amounts than the intermediate terms,

Get.
For example, as a numerical example, to achieve a power transmission efficiency of 96% or higher through the tire, that is, | S ₂₁ | ² > 0.96

Ie

Should be set.

  The above operation analysis is also valid for the embodiments of FIGS. Thus, even if the tire has a higher resistance value than the power supply impedance and the load impedance, the present invention can transmit the power efficiently through the tire. For example, it is effective in a system for charging electric energy to a traveling vehicle through a set of two tires.

  INDUSTRIAL APPLICABILITY The present invention can be used in a stable and highly efficient power supply apparatus and power supply method for an electric vehicle such as an electric vehicle. It can be used for power feeding while traveling.

DESCRIPTION OF SYMBOLS 11 ... 1st tire 12 ... 2nd tire 13 ... Steel belt 21 ... 1st conductor 22 ... 2nd conductor 30 ... Power supply device 40 ... Power receiving apparatus 41 ... 1st electrode 42 ... 2nd electrode

Claims (11)

The first tire inner conductor and the second conductor of the first tire are composed of a first conductor installed below the first tire of the vehicle and a second conductor installed below the second tire of the vehicle. via the second tire inner conductor having a tire, a vehicle power supply device that supplies power to the vehicle,
A first electrode disposed in the vehicle in proximity to the first tire and capacitively coupled to the first tire conductor;
A second electrode disposed in the vehicle in proximity to the second tire and capacitively coupled to the second tire inner conductor;
A vehicle power feeding device comprising: a power receiving device that receives AC power fed between the first conductor and the second conductor by the first electrode and the second electrode.   The power receiving device includes a capacity between the first conductor and the first tire inner conductor, a capacity between the first electrode and the first tire inner conductor, and a capacity between the second conductor and the second tire inner conductor. 2. The vehicle power feeding device according to claim 1, further comprising a coil that causes resonance in a circuit including a capacitance between the second electrode and the second in-tire conductor.   The said 1st conductor and the said 2nd conductor are installed on the road surface where the said 1st tire and the said 2nd tire drive | work, or are embed | buried under the road surface, The Claim 1 or Claim characterized by the above-mentioned. The vehicle electric power feeder of Claim 2.   The said 1st conductor and the said 2nd conductor are installed on the road surface which the said 1st tire and the said 2nd tire contact at the time of parking, or are embed | buried under the road surface, The vehicle electric power feeder of Claim 2. In a power supply device for a vehicle,
A first conductor installed below the first tire of the vehicle;
A second conductor installed below the second tire of the vehicle;
Said first proximate the tire, the first attached the conductor and the capacitance TIRES first Yusuke of the tire, the first electrode disposed on the vehicle,
Said second proximate to the tire, the second attached in the conductor and the capacitance TIRES second Yusuke of the tire, a second electrode disposed on the vehicle,
A vehicle power feeding device comprising: a power receiving device that receives AC power fed between the first conductor and the second conductor by the first electrode and the second electrode.   The power receiving device includes a capacity between the first conductor and the first tire inner conductor, a capacity between the first electrode and the first tire inner conductor, and a capacity between the second conductor and the second tire inner conductor. The vehicle power feeding device according to claim 5, further comprising a coil that causes resonance in a circuit including a capacitance between the second electrode and the second in-tire conductor.   The vehicle power feeding device according to claim 5, further comprising a power supply device that supplies the AC power between the first conductor and the second conductor.   The power supply device includes a capacitance between the first conductor and the first tire inner conductor, a capacitance between the first electrode and the first tire inner conductor, and a capacitance between the second conductor and the second tire inner conductor. The vehicle power feeding device according to claim 7, further comprising a coil that causes resonance in a circuit including a capacitance between the second electrode and the second in-tire conductor. In a method for supplying power to a vehicle,
The first conductor is installed on the road surface where the first tire of the vehicle contacts, or below the road surface,
The second conductor is installed on the road surface where the second tire of the vehicle contacts, or below the road surface,
Wherein the first proximity to the tire, disposed a first electrode coupled first tire inner conductor and the capacitance that Yusuke of said first tire on the vehicle,
The second proximity to the tire, disposed a second electrode coupled second tire inner conductor and a capacitor that Yusuke of the second tire on the vehicle,
A vehicle power supply method, wherein AC power is supplied between the first conductor and the second conductor, and the AC power is received by the first electrode and the second electrode. The capacitance between the first conductor and the first tire inner conductor and the capacitance between the first electrode and the first tire inner conductor, the capacitance between the second conductor and the second tire inner conductor and the second electrode, The vehicle power feeding method according to claim 9, wherein in the circuit including the capacitance between the second tire inner conductors, the coil is used to resonate and feed power.   The vehicle power feeding method according to claim 9 or 10, wherein power feeding to the vehicle is performed when the vehicle is traveling on a road surface.

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