Power supply system and power supply structure using electric field coupling scheme

Abstract

To simultaneously achieve power supply at a free position, cable-less operation, and securing protective grounding, relative to an electric apparatus on a power receiving side in an electric field coupling scheme power supply system.SOLUTION: A power supply structure at least includes: a power transmission side electrode unit 10 connected to one pole side of a high frequency power source 50; a grounding unit 30 connected to the other pole side of the high frequency power source 50 and connected to a ground 40; a power receiving side electrode unit 60 connected to one pole side of a load 90; and a conductive unit 80 connected to the other pole side of the load 90. The power supply structure executes wireless power transmission using an electric field coupling by an opposed arrangement of the power transmission side electrode unit 10 and the power receiving side electrode unit 60 in a state where the conductive unit 80 and the grounding unit 30 are brought into contact and protective grounding on the load 90 side is secured.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a power supply system and a power supply structure using an electric field coupling method, and more particularly to a power supply system and a power supply structure that enable power supply in a free position, make a power-receiving electric device to be supplied with power cableless, and can be reliably grounded. [Background technology]

[0002] The capacitive coupling method, known as one type of wireless power supply, involves installing electrodes on both the transmitting and receiving sides and supplying power by utilizing a capacitor formed between the electrodes when the electrodes are brought into close proximity to each other. As a power supply system using this electric field coupling method, for example, the charging system described in Patent Document 1 below is known. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6117314 Summary of the Invention [Problem to be solved by the invention]

[0004] One possible application example of a power supply system using the electric field coupling method is to incorporate power transmission modules into the floors and walls of a facility, roads, and fixtures such as desks and cabinets installed within a structure, and to incorporate power receiving modules into various electrical devices (including batteries, the same applies below) used within the structure, enabling power supply in any position. However, if protective grounding is required for this electrical equipment, it will be necessary to prepare a separate earth cable for the electrical equipment and connect this earth cable to an earth terminal installed on the floor or wall within the facility. As a result, while the power transmission and reception itself is realized via wireless power supply, the placement of the electrical equipment is ultimately restricted due to the constraints imposed by the length of the earth cable extending from the electrical equipment incorporating the power receiving module, losing the advantage of being able to supply power in any position. In addition, there is the problem that this earth cable can become an obstacle to the passage of people, the movement of goods, cleaning work, etc.

[0005] The above problem is one of the obstacles to wireless power supply to medical electrical equipment belonging to Class I, which requires protective earthing as specified in "JIS T 0601-1."

[0006] Therefore, one of the objects of the present invention is to provide a means for simultaneously realizing free-position power supply, cable-less operation, and protective earthing for a power-receiving electrical device in an electric field coupling type power supply system. [Means for solving the problem]

[0007] The present invention, made to solve the above-mentioned problems, is a power supply system using electric field coupling, comprising a power transmission module and a power receiving module that can be arranged opposite each other, wherein the power transmission module has at least a power transmission side electrode portion, a power transmission side insulating portion, and a grounding portion, which are arranged in that order toward the side opposite the power receiving module, and the power receiving module has at least a power receiving side electrode portion, a power receiving side insulating portion, and a conductive portion, which are arranged in that order toward the side opposite the power transmission module, the grounding portion is connected to a high-frequency power source and an earth, and the conductive portion is connected to a load, and when the power transmission module and the power receiving module are arranged opposite each other, the grounding portion and the conductive portion are in contact with each other to ensure protective grounding on the load side, and wireless power transmission is performed between the power transmission side electrode portion and the power receiving side electrode portion. The present invention also provides a power supply structure using electric field coupling, comprising at least a high-frequency power source, a power transmitting side electrode section connected to one pole side of the high-frequency power source, a grounding section connected to the other pole side of the high-frequency power source and connected to earth, a load, a power receiving side electrode section connected to one pole side of the load, and a conductive section connected to the other pole side of the load, wherein protective grounding of the load side is ensured by contact between the conductive section and the grounding section, and wireless power transmission using electric field coupling is performed by arranging the power transmitting side electrode section and the power receiving side electrode section opposite each other.

[0008] In the present invention, the ground portion and the conductive portion may be configured in a lattice pattern. The present invention may also be configured to further include a distance adjustment unit capable of adjusting a distance between the power receiving module and the power transmitting module. In addition, the present invention may have a configuration in which the power receiving module is incorporated into an electrical device that requires protective earthing. The present invention may also be configured such that the power transmission module is incorporated into a floor, wall, or fixture within a medical facility, and the power receiving module is incorporated into medical electrical equipment that requires protective earthing. Effect of the Invention

[0009] According to the present invention, in an electric field coupling type power supply system and power supply structure, it is possible to simultaneously realize power supply in a free position, cable-less operation, and the assurance of protective earthing for a power-receiving electric device. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic diagram showing an overall structure of a power supply system according to a first embodiment. [Diagram 2] 3 is a schematic diagram showing opposing surfaces of a power transmitting module and a power receiving module; [Diagram 3] FIG. 2 is a diagram showing an equivalent circuit of a power supply system according to the present invention. [Figure 4] FIG. 11 is a schematic diagram of a power supply system according to a second embodiment. [Diagram 5] FIG. 1 is a diagram showing a conventional wireless power supply circuit using an electric field coupling method. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. EXAMPLES

[0012] First, a first embodiment of the present invention will be described with reference to FIGS.

[0013] <1> Overall configuration (Fig. 1) The power supply system of this embodiment is a wireless power supply system using an electric field coupling method, and includes a power transmission module A and a power receiving module B, as shown in FIG. 1. When the modules are brought into contact with each other so as to face each other, wireless power transmission is performed by electric field coupling using high frequency waves flowing from a high frequency power source 50, thereby supplying power (including charging; the same applies below) to an electronic device (including a battery) having a load 90 incorporating the power receiving module B. In this embodiment, the power transmitting module A includes at least a power transmitting side electrode unit 10, a power transmitting side insulating unit 20, and a ground unit 30, which are arranged in this order toward the side facing the power receiving module B. The power receiving module B includes, as its constituent elements, at least a power receiving side electrode section 60, a power receiving side insulating section 70, and a conductive section 80, which are arranged in this order toward the side opposite the power transmitting module A. Each element will be described in detail below.

[0014] <2> Power transmission electrode section (Fig. 1) The power transmitting side electrode unit 10 is a member provided in the power transmitting module A and serves as one electrode of a capacitor in a wireless power feeding circuit using an electric field coupling method. The power transmitting electrode unit 10 is connected to one pole of a high frequency power supply 50 .

[0015] <3> Transmission side insulation section (Fig. 1) The power transmission side insulating section 20 is a member provided in the power transmission module A to electrically insulate the power transmission side electrode section 10 from the outside of the power transmission module A. The power transmitter side insulating section 20 may be made of any material that has electrical insulation properties and can cover the power transmitter side electrode section 10, and insulating materials in a sheet shape, film shape, or any other shape can be used.

[0016] <4> Grounding part (Fig. 1) The ground portion 30 is a member that is provided on the power transmission module A and is intended to be connected to the earth 40. The grounding portion 30 can be configured as a conductive member having one end connected to both the other pole of the high-frequency power supply 50 and the earth 40 and the other end exposed to the opposing surface of the power transmission module A.

[0017] <4.1> Shape of the contact part (Fig. 2) In the present invention, the grounding portion 30 can have any shape, structure, etc., as long as it is configured to have a space on the surface of the power transmission module A facing the power receiving module B that can come into contact with the conductive portion 80 and induce electric charge to the power transmitting side electrode portion 10 and the power receiving side electrode portion 60. For example, it is possible to arrange linear or strip-shaped conductive members at intervals in one direction, or to arrange them vertically and horizontally in a lattice pattern, or to arrange them in a spiral pattern, thereby providing openings partitioned by the conductive members, or to provide holes or slits by punching a flat conductive member, or to combine the above-mentioned methods appropriately. In this embodiment, a lattice-shaped ground portion 30 is used (FIG. 2).

[0018] <4.2> Facing surface of the power transmission module (Fig. 1) In the present invention, the unevenness of the opposing surface of the power transmission module A having the grounding portion 30 does not matter, but it is preferable to expose the grounding portion 30 on the opposing surface and configure the opposing surface to be smooth so as not to hinder the passage of people, the movement of objects, cleaning work, etc. at the installation location of the power supply system of the present invention. Methods for realizing the above configuration include arranging the grounding part 30 so as to be embedded in the power transmission side insulating part 20 and aligning the surface positions of both, and using a flat conductive member that maintains as smooth a surface as possible by punching the grounding part 30. Also, openings partitioned by the conductive member that constitutes the grounding part 30 may be filled with an insulator to make the opposing surfaces of the power transmission module flush with each other.

[0019] <5> Receiving electrode part (Fig. 1) The power receiving side electrode unit 60 is a member provided on the power receiving module B, and serves as the other electrode constituting a capacitor in a wireless power feeding circuit using an electric field coupling method. The power receiving electrode is connected to one pole of a load 90 . <6> Receiving side insulation part (Fig. 1) The power-receiving-side insulating section 70 is a member provided in the power-receiving module B to electrically insulate the power-receiving-side electrode section 60 from the outside of the power-receiving module B. The power-receiving side insulating portion 70 may be made of any material that has electrical insulation properties and is capable of covering the power-receiving side electrode portion 60, and insulating materials in a sheet, film, or any other shape can be used.

[0020] <7> Conductive part (Figure 1) The conductive portion 80 is a member provided in the power receiving module B for contacting the ground portion 30 provided in the power transmitting module A when wireless power supply from the power transmitting module A is to be received. The conductive portion 80 can be configured from a conductive member having one end connected to the other pole of the load 90 and the other end exposed to the opposing surface of the power receiving module B.

[0021] <7.1> Shape of conductive part (Fig. 2) In the present invention, the conductive portion 80 can have any shape, structure, etc. as long as it is configured to be in contact with the ground portion 30 and have a space that can induce electric charge to the power transmitting side electrode portion 10 and the power receiving side electrode portion 60. For example, linear or strip-shaped conductive members may be arranged at intervals in one direction, or arranged vertically and horizontally in a lattice pattern, or arranged in a spiral pattern, to provide openings partitioned by the conductive members, or a flat conductive member may be punched to provide holes or slits, or the above-mentioned patterns may be appropriately combined to provide a configuration in which the surface of the power receiving module B facing the power transmitting module A includes a mixture of areas where the power receiving side insulating section 70 is visible and areas where the conductive section 80 is visible. The layout and spacing of each conductive member may be determined by design in a suitable manner, taking into consideration the structure of the grounding portion 30 described above. In this embodiment, as shown in FIG. 2, a conductive portion 80 is used.

[0022] <7.2> Opposing surface of the power receiving module (Fig. 2) In the present invention, the unevenness of the opposing surface of the power receiving module B having the conductive portion 80 is not an issue, but from the standpoint of installation stability during power supply, the opposing surface of the power receiving module B may be configured to be smooth, similar to the grounding portion 30.

[0023] <8> Usage image (Fig. 1) Next, an image of how the power supply system according to the present invention is used will be described. As shown in Figure 1, when the power transmission module A and the power receiving module B are arranged opposite each other and the grounding portion 30 and the conductive portion 80 come into contact with each other, a wireless power supply circuit capable of passing electricity between the power transmission module A and the power receiving module B is formed.

[0024] <8.1> Comparison on equivalent circuits (Fig. 3, Fig. 5) FIG. 3 is an equivalent circuit of a wireless power supply circuit realized by the power supply system according to this embodiment. The equivalent circuit shown in FIG. 3 constitutes a parallel resonant power transmission circuit, and includes a high-frequency power supply 50, a transformer consisting of inductances L1 and L2, a transformer consisting of inductances L3 and L4, a load 90, a capacitor C consisting of the power transmitting side electrode unit 10 and the power receiving side electrode unit 60, resonant capacitors C1 and C2, and an earth 40. Power transmission is possible without using a resonant type in the power transmission circuit. However, in the present invention, since the ground part 30 and the conductive part 80 are in contact with each other, the gap between the power transmitting side electrode part 10 and the power receiving side electrode part 60 is kept constant, so that power transmission using a resonant type provides better transmission efficiency.

[0025] In the conventional wireless power feeding circuit using an electric field coupling method shown in Figure 5, two combinations of electrodes on the transmitting side and the receiving side are provided on the circuit (a pair of electrode sets a1, a2). In the power feeding circuit of the present invention, however, one of the electrode sets a2 is replaced with direct wiring resulting from contact between the grounding part 30 and the conductive part 80 described in Figure 1, and protective grounding on the receiving side is secured by earth 40 provided in the transmitting side circuit, so that wireless power feeding is performed with what appears to be a single electrode set, which is different.

[0026] <8.2> Power supply function (Fig. 2, Fig. 3) With the above-described configuration, in the power supply system of the present invention, when the power transmission module A and the power receiving module B are arranged opposite each other, wireless power transmission is performed between the power transmission side electrode unit 10 and the power receiving side electrode unit 60 while the grounding portion 30 and the conductive portion 80 are in contact with each other, ensuring protective grounding on the load 90 side. Furthermore, even if the power receiving module B is moved above the power transmitting module A, wireless power transmission will occur between the power transmitting side electrode unit 10 and the power receiving side electrode unit 60 as long as the grounding portion 30 and the conductive portion 80 are positioned so as to be in contact with each other. As a result, there is no need to install a separate earth cable in electrical equipment incorporating the power receiving module B, which not only removes restrictions on power supply in a free position, but also eliminates the disruption to people's passage or the movement of goods that would be caused by an earth cable. EXAMPLES

[0027] [Adding a gap adjustment unit (Fig. 4)] A second embodiment of the present invention will now be described with reference to FIG. The power supply system according to the present invention can be configured to further include a distance adjustment unit 100 capable of adjusting the distance between the power receiving module B and the power transmitting module A. In the power supply system of this embodiment shown in Figure 4, an electrical device (power receiving device D) incorporating a power receiving module B is provided with wheels for movement, and this power receiving device D and the power receiving module B are shown connected by a distance adjustment unit 100 composed of a cylinder that can be expanded and contracted in the vertical direction. By making it possible to adjust the distance between the power receiving module B and the power transmitting module A by raising and lowering the power receiving module B using the distance adjustment unit 100, it is possible to switch power supply on and off as needed while leaving the power receiving device D in the same location. Generally, medical equipment with casters is provided with a foot-operated stopper, and the power receiving module A may be raised and lowered in conjunction with the operation of this stopper.

[0028] It should be noted that the embodiments disclosed herein are merely illustrative and not restrictive. The scope of the present invention is defined by the claims rather than the above description, and is intended to include all modifications within the scope and meaning equivalent to the claims. [Industrial Applicability]

[0029] The power supply system according to the present invention can be applied to cases where it is required to achieve both cable-less operation and the assurance of protective earthing for a power-receiving electrical device. More specifically, for example, the power transmission module can be installed on the floor of a medical facility so that it is flush with the floor, and the power receiving module can be installed in medical electrical equipment (class I electrical equipment that requires protective grounding as specified in JIS T 0601-1) used in the medical facility, enabling the medical electrical equipment to be powered wirelessly. [Explanation of symbols]

[0030] A: Power transmission module B: Power receiving module D: Power receiving device 10: Power transmission electrode part 20: Power transmission side insulation part 30: Grounding part 40: Earth 50: High frequency power supply 60: Receiving electrode part 70: Receiving side insulation part 80: Conductive part 90: Load 100: Spacing adjustment section a1, a2: a pair of electrodes

Claims

1. A power supply system using electric field coupling, A power transmission module and a power receiving module that can be arranged opposite each other are provided, The power transmission module includes: the power receiving module, and at least a power transmitting side electrode portion, a power transmitting side insulating portion, and a ground portion, which are arranged in this order toward a side facing the power receiving module; The power receiving module includes: the power receiving module includes at least a power receiving side electrode portion, a power receiving side insulating portion, and a conductive portion, which are arranged in this order toward a side facing the power transmitting module, The grounding portion is connected to a high frequency power source and a ground. The conductive portion is connected to a load, When the power transmitting module and the power receiving module are disposed opposite to each other, the grounding portion and the conductive portion are in contact with each other to ensure protective grounding on the load side, and wireless power transmission is performed between the power transmitting side electrode portion and the power receiving side electrode portion. A power supply system using capacitive coupling.

2. The ground portion and the conductive portion have a lattice shape. A power supply system using the electric field coupling method according to claim 1.

3. The power receiving module further includes a distance adjustment unit capable of adjusting a distance between the power receiving module and the power transmitting module. A power supply system using the electric field coupling method according to claim 1.

4. The power receiving module is incorporated in an electrical device that requires protective grounding. A power supply system using the electric field coupling method according to claim 1.

5. The power transmission module is incorporated into a floor, a wall, or a fixture in a medical facility; The power receiving module is incorporated in a medical electrical device that requires protective grounding. A power supply system using the electric field coupling method according to claim 1.

6. A power supply structure using electric field coupling, A high frequency power source; A power transmission side electrode unit connected to one pole side of the high frequency power supply; a grounding portion connected to the other pole side of the high frequency power supply and to a ground; Load and a power receiving electrode portion connected to one pole side of the load; The load is connected to the other pole side of the conductive portion. The conductive portion and the ground portion are in contact with each other to ensure protective grounding of the load side, and wireless power transmission is performed using electric field coupling by arranging the power transmitting side electrode portion and the power receiving side electrode portion opposite each other. Power supply structure.

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