Power supply structure using electric field coupling system

Abstract

To enable continuous power supply even when a travel body traveling in any direction of a flat face on a road face (including floor face) is in the middle of traveling in a power supply structure for performing wireless power supply using an electric field coupling system.SOLUTION: A power supply structure for wirelessly supplying power to a travel body A traveling on a road face B includes at least: a power transmission side electrode part 20 connected to one pole side of a high frequency power supply 10; a power transmission side conductive part 30 connected to the other pole side of the high frequency power supply 10; a power reception side electrode part 60 connected to one pole side of a load 50; and a power reception side conductive part 70 which is provided on a wheel A2 of the travel body A and is connected to the other pole side of the load 50. When the travel body A is positioned on the road face B, the power transmission side conductive part 30 is brought into contact with the power reception side conductive part 70, and the power transmission side electrode part 20 and the power reception side electrode part 60 are oppositely arranged, whereby wireless power transmission using unipolar electric field coupling is performed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a power supply structure for wirelessly supplying power to a traveling object traveling on a road surface from the road surface using an electric field coupling method. [Background technology]

[0002] One type of wireless power supply is known as the capacitive coupling method. The electric field coupling method is a method in which electrodes are installed on both the power transmitting and receiving sides, and power is supplied by utilizing the transfer of electric charges that are formed between the electrodes when the electrodes are close to each other. An example of a power supply system using this electric field coupling method is the power supply system described in Patent Document 1 below. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2024-6233 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when power supply during movement is considered in the system described in Patent Document 1, although continuous power supply is possible in the longitudinal direction of the two pole pairs, continuous power supply while moving in any direction in a plane is not possible.

[0005] Therefore, one of the objects of the present invention is to provide a power supply structure for wirelessly supplying power from the road surface using an electric field coupling method to a vehicle traveling in any horizontal direction on the road surface, and to provide a means for continuous power supply even while the vehicle is traveling. [Means for solving the problem]

[0006] The present invention, which has been made to solve the above-mentioned problems, is a power supply structure for wirelessly supplying power from a road surface to a running body running on the road surface, wherein the road surface has at least a high-frequency power source, a power transmitting side electrode portion connected to one pole side of the high-frequency power source, and a power transmitting side conductive portion connected to the other pole side of the high-frequency power source, and the running body has at least a load, a power receiving side electrode portion connected to one pole side of the load, and a power receiving side conductive portion connected to the other pole side of the load, and the power receiving side conductive portion is provided on a wheel of the running body, and when the running body is positioned on the road surface, the power transmitting side conductive portion and the power receiving side conductive portion come into contact and the power transmitting side electrode portion and the power receiving side electrode portion are arranged opposite each other, so that wireless power transmission using electric field coupling is performed. In the present invention, the power-receiving-side conductive portion may be configured as a ring-shaped or mesh-shaped conductive member disposed on the outer circumferential surface of the wheel. In the present invention, the power-receiving-side electrode portion may be configured as a ring-shaped electrode plate disposed inside the wheel. In the present invention, the power-receiving-side electrode portion may be provided on both the main body and the wheel of the traveling object. In the present invention, the power-transmitting-side conductive portion may be connected to earth. [Effects of the Invention]

[0007] According to the present invention, even when a traveling object including a power supply target is traveling in any direction on the road surface, wireless power supply from the road surface using the electric field coupling method can be performed. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic side view showing the overall configuration of a power supply structure according to a first embodiment. [Figure 2] FIG. 2 is a schematic plan view showing a configuration example of a power-transmitting-side conductive part in the first embodiment. [Figure 3] 1 is a schematic front view showing an example of the configuration of a wheel in a first embodiment. [Figure 4] FIG. 2 is a diagram showing an equivalent circuit of the power supply system according to the present invention. [Figure 5]FIG. 1 is a diagram showing a conventional wireless power supply circuit using an electric field coupling method. [Figure 6] FIG. 10 is a schematic diagram showing an example of the configuration of a wheel in a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. [Example]

[0010] <1> Overall overview (Figure 1) The power supply structure according to the present invention is premised on wireless power supply using an electric field coupling method between a power transmitting device and a power receiving device that are in a relatively movable relationship. In the present invention, either one of the power transmitting device and the power receiving device may move, or both may move. In this embodiment (FIG. 1), the components of the power transmitting side device are provided on a road surface B, and the components of the power receiving side device are provided on a traveling object A that can travel on the road surface B.

[0011] <1.1> Running body (Fig. 1) The running object A in the present invention is not particularly limited in type or size, and includes any object that can run by rotation of wheels A2 provided on the main body A1 of the running object A. Specific examples of the traveling object A in the present invention include an electric car, a train, an electric wheelchair, a wagon or a transport cart for transporting mounted electronic equipment, and the like. In the power supply structure according to the present invention, the member to be supplied with power may be a driving source of the running object A or an electronic device mounted on the running object A.

[0012] <1.2> Road surface (Fig. 1) The road surface B in the present invention includes any place on which the traveling object A can travel. Specific examples of the road surface B in the present invention include a road and a floor.

[0013] <1.3> Components (Fig. 1) As shown in FIG. 1 , the power supply structure according to the present invention includes, as components on the power transmission side, a power transmission side electrode section 20, a power transmission side conductive section 30, and a power transmission side insulating section 40, and, as components on the power receiving side, a power receiving side electrode section 60, a power receiving side conductive section 70, and a power receiving side insulating section 80. When the running object A is on the road surface B, the power transmitting electrode unit 20 and the power receiving electrode unit 60 are arranged opposite each other, and wireless power transmission by electric field coupling is performed via the power transmitting electrode unit 20 and the power receiving electrode unit 60 using high frequency waves flowing from the high frequency power supply 10 provided on the power transmitting side, and power is supplied (including charging, same below) to a power supply target (including a power storage device, same below) having a load 50 provided on the power receiving side. Each part will be described in detail below.

[0014] <2> Power transmission electrode (Fig. 1) The power transmitting electrode section 20 is a member that serves as one electrode of a capacitor in a wireless power feeding circuit using an electric field coupling method. The power-transmitting-side electrode section 20 is connected to one pole of the high-frequency power supply 10 .

[0015] <3> Transmission side insulation section (Fig. 1) The power-transmitting-side insulating section 40 is a member for electrically insulating the power-transmitting-side electrode section 20 from the outside. The power transmitting side insulating section 40 may be made of any material that has electrical insulation properties and can cover the power transmitting side electrode section 20, and insulating materials in sheet form, film form, or any other shape may be used.

[0016] <4> Conductive part on the power transmission side (Fig. 1) The power-transmitting-side conductive part 30 is a member for coming into contact with the power-receiving-side conductive part 70. The power transmission side conductive part 30 is made of a conductive material, one end of which is arranged so as to be exposed on the surface of the road surface B, and the other end of which is connected to the other pole of the high frequency power source 10.

[0017] 4.1 Example of the configuration of the power transmission side conductive part (Fig. 2) In the present invention, the power transmitting side conductive part 30 may have any shape, structure, etc., as long as it can contact and conduct electricity with the power receiving side conductive part 70 described below while ensuring a space in which electric charge can be induced in the power transmitting side electrode part 20 and the power receiving side electrode part 60 when wireless power supply is performed. Possible configuration examples of the power transmission side conductive portion 30 include a configuration in which linear or strip-shaped conductive members are arranged at intervals in one direction, arranged in a lattice pattern in the vertical and horizontal directions to form a mesh, or arranged in a spiral, thereby providing openings partitioned by the conductive members, a configuration in which holes or slits are provided by punching a flat conductive member, or an appropriate combination of the above-mentioned configurations. In this embodiment, as shown in FIG. 2, the power-transmitting-side conductive portion 30 is configured by arranging conductive members in a lattice pattern and providing openings.

[0018] <5> Receiver electrode (Fig. 1) The power receiving electrode section 60 is a member that serves as the other electrode of a capacitor in a wireless power feeding circuit using an electric field coupling method. In the present invention, the location where the power-receiving-side electrode section 60 is provided is not particularly limited. In this embodiment, the power receiving electrode unit 60 is provided at the bottom of the main body A1 constituting the traveling body A so as to face the power transmitting electrode unit 20. The power-receiving-side electrode unit 60 is connected to one pole of the load 50 .

[0019] <6> Insulation section on the receiving side (Fig. 1) The power-receiving-side insulating section 80 is a member for electrically insulating the power-receiving-side electrode section 60 from the outside. The power-receiving-side insulating portion 80 may be made of any material that has electrical insulation properties and can cover the power-receiving-side electrode portion 60, and insulating materials in sheet, film, or any other shape may be used.

[0020] <7> Receiving side conductive part (Figure 1) The power-receiving-side conductive part 70 is a member for forming a contact point with the power-transmitting-side conductive part 30 when wireless power feeding is performed. In the present invention, the power receiving side conductive part 70 may have any shape, structure, etc., as long as it can maintain contact with the power transmitting side conductive part 30, which is exposed to the road surface B, when the running object A runs on the road surface B. For example, as shown in Figure 1, by providing a power receiving side conductive part 70 on the outer peripheral surface of a wheel A2 of a running body A, when the running body A runs on a road surface B, the power receiving side conductive part 70 can maintain contact with the power transmitting side conductive part 30 exposed to the road surface B. In the present invention, it is not essential that all of the wheels A2 constituting the traveling object A are provided with the power-receiving-side conductive portion 70. The power-receiving-side conductive portion 70 can be configured from a conductive member having one end connected to the other pole of the load 50 and the other end exposed on the opposing surface of the power-receiving module.

[0021] 7.1 Example of the configuration of the receiving side conductive part (Fig. 3) FIG. 3 shows an example of the configuration of the power-receiving-side conductive portion 70 in the wheel A2. In Figure 3, the receiving side conductive part 70 is composed of a cylindrical conductive member having an outer diameter approximately the same as the diameter of the wheel A2, and this conductive member is arranged inside the wheel A2 so that it is exposed to the outer surface of the wheel A2. The conductive member constituting the power receiving side conductive part 70 may be made of conductive rubber having elasticity equivalent to that of the rubber constituting the wheel A2 so as not to damage the road surface B by contact with the road surface. The power-receiving-side conductive portion 70 may also be configured with a plurality of ring-shaped conductive members arranged therein, or may have a circumferential surface made of a mesh-shaped conductive member. The wiring extending from the power-receiving-side conductive portion 70 is connected to the other pole of the load 50 via components of the traveling object A, such as the wheel of the wheel A2 and a shaft connected to the wheel.

[0022] <7.2> Number of conductive parts on the receiving side In the present invention, the power-receiving-side conductive portion 70 may be provided on any one of the wheels A2 constituting the running body A, or the power-receiving-side conductive portion 70 may be provided on each of the plurality of wheels A2. Providing a power receiving side conductive part 70 on each of multiple wheels A2 is advantageous in that even if one wheel A2 moves away from the road surface B, wireless power supply can be maintained as long as the other wheel A2 is in contact with the road surface B.

[0023] <8> Equivalent circuit (Figure 4) FIG. 4 is an equivalent circuit of a wireless power supply circuit realized by the power supply structure according to the present invention. The equivalent circuit shown in Figure 4 constitutes a parallel resonant power transmission circuit and includes a high-frequency power supply 10, a transformer consisting of inductances L1 and L2, a transformer consisting of inductances L3 and L4, a load 50, a capacitor C consisting of a power transmitting side electrode unit 20 and a power receiving side electrode unit 60, and resonant capacitors C1 and C2. Transmission is possible without using a resonant type power transmission circuit. However, in the present invention, the power transmitting side conductive part 30 and the power receiving side conductive part 70 are in contact with each other, and the gap between the power transmitting side electrode part 20 and the power receiving side electrode part 60 is kept constant, so that resonant power transmission is expected to improve transmission efficiency.

[0024] <9> Comparison with conventional wireless power supply circuits (Fig. 5, Fig. 4) FIG. 5 is an equivalent circuit diagram of a conventional wireless power feeding circuit using an electric field coupling method. In the conventional wireless power feeding circuit using the electric field coupling method shown in Figure 5, a combination of a power transmitting electrode and a power receiving electrode is provided in two locations on the circuit (a pair of electrode sets a1 and a2), and wireless power feeding is performed using two electrode sets (a bipolar wireless power feeding circuit). On the other hand, in the wireless power feeding circuit according to the present invention, as shown in FIG. 4, one of the electrode sets a2 in FIG. 5 is replaced with direct wiring resulting from contact (formation of a contact point) between the power transmitting side electrode section 20 and the power receiving side electrode section 60, so that wireless power feeding is apparently performed using one electrode set (a single-pole wireless power feeding circuit).

[0025] <10> summary The power supply structure according to the present invention can provide the following advantageous effects. (1) When the moving object A is stopped on the road surface B, and even when the moving object A is moving on the road surface B, wireless power transmission will be performed between the power transmitting side electrode unit 20 and the power receiving side electrode unit 60 as long as the power receiving side electrode unit 60 and the power receiving side conductive unit 70 provided on the moving object A do not come off the power transmitting side electrode unit 20 and the power transmitting side conductive unit 30 provided on the road surface B. Therefore, by widely distributing the power transmission side electrode portion 20 and the power transmission side conductive portion 30 on the road surface B, power can be constantly supplied from the road surface B to the traveling object A traveling on the road surface in any horizontal direction. (2) Because the power transmitting-side conductive part 30 and the power receiving-side conductive part 70 are in contact with each other, if the power transmitting-side circuit is connected to earth, protective grounding for the power receiving-side electrical device can be ensured, eliminating the need for a separate earth wire from the power receiving-side electrical device. Therefore, the power supply structure according to the present invention is suitable for cases where both cable-less operation and protective grounding are required for the power receiving-side electrical device. More specifically, the power transmitting-side components are incorporated into a wagon or similar device that carries medical electrical equipment (class I electrical equipment that requires protective grounding as defined in JIS T 0601-1) used in the medical facility, enabling wireless power supply to the medical electrical equipment. (3) By connecting the power-transmitting-side conductive part 30 to earth, the traveling object A is also earthed, which has the effect of preventing electric shock to the human body. [Example]

[0026] A second embodiment of the power supply structure according to the present invention will be described with reference to FIG.

[0027] <1> Change in the arrangement of the receiving electrode In this embodiment, the power-receiving-side electrode unit 60, which was arranged on the bottom of the main body A1 of the traveling object A in the first embodiment, is moved to the inside of the wheel A2. In this embodiment, the power-receiving-side electrode section 60 rotates together with the wheel A2, and therefore, like the power-receiving-side conductive section 70, an electrode plate formed in a ring shape is used. In this case, if the wheel A2 is made of insulating rubber, the wheel A2 also serves as the power-receiving-side insulating portion 80. Then, the wiring extending from the power receiving side electrode part 60 embedded in the wheel A2 is connected to one pole of the load 50, passing through components of the running body A such as the wheel of the wheel A2 and the shaft connected to the wheel, in the same manner as the power receiving side conductive part 70. In addition, in this embodiment, since the power receiving side electrode portion 60 is arranged inside the wheel A2, a power receiving side conductive portion 70 is provided with an opening portion by arranging multiple conductors 71 at intervals so that they are exposed on the outer peripheral surface of the wheel A2.

[0028] <2> summary The power supply structure according to this embodiment can also provide the same effects as those obtained in the first embodiment. The power supply structure according to this embodiment is particularly useful when circumstances make it impossible to place the power-receiving-side electrode unit 60 on the bottom of the main body of the running object A. It is also useful in that the number of electrodes can be increased when the running object A has a large number of wheels A2. [Example]

[0029] The present invention may be configured as a combination of the first and second embodiments, in which the power-receiving-side electrode unit 60 is provided on both the bottom of the main body of the traveling object A and the wheel A2 (not shown). This embodiment further contributes to improving the power supply capacity. [Explanation of symbols]

[0030] A: Running body A1: Main body A2: Wheels B: Road surface D: Contact point 10:High frequency power supply 20: Power transmission electrode 30: Power transmission side conductive part 40: Transmission side insulation part 50: Load 60: Receiving electrode part 70: Receiving side conductive part 71: Conductor 80: Receiving side insulation part a1, a2: a pair of electrodes

Claims

1. A power supply structure for wirelessly supplying power from a road surface to a traveling object traveling on the road surface, The road surface is A high frequency power source; a power transmission side electrode portion connected to one pole side of the high frequency power supply; a power transmission side conductive portion connected to the other pole side of the high frequency power supply, The traveling body is Load and a power receiving electrode portion connected to one pole side of the load; The power receiving circuit has at least a power receiving-side conductive portion connected to the other pole side of the load, the power-receiving-side conductive portion is provided on a wheel of the traveling body; When the traveling object is positioned on the road surface, the power transmitting-side conductive portion and the power receiving-side conductive portion come into contact with each other, and the power transmitting-side electrode portion and the power receiving-side electrode portion are arranged opposite each other, thereby performing wireless power transmission using electric field coupling. Power supply structure using capacitive coupling method.

2. The power-receiving-side conductive portion is made of a ring-shaped or mesh-shaped conductive member disposed on the outer circumferential surface of the wheel. A power supply structure using the electric field coupling method according to claim 1.

3. The power receiving electrode portion is formed of a ring-shaped electrode plate disposed inside the wheel. A power supply structure using the electric field coupling method according to claim 1.

4. The power receiving electrode unit is provided on both the main body and the wheel of the traveling body. A power supply structure using the electric field coupling method according to claim 1.

5. The power transmission side conductive part is connected to earth. A power supply structure using the electric field coupling method according to claim 1.

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