Non-contact power supply system and power transmission device

Abstract

To provide a non-contact power supply system and a power transmission device capable of improving the degree of freedom of installation.SOLUTION: The non-contact power supply system 1 supplies power to a load 4 in a non-contact manner, and includes a power transmission device 2 and a power reception device 3. The power transmission device 2 includes a high-frequency power source 21 that outputs high-frequency power, a power transmission electrode 22 that transmits the power output from the high-frequency power source 21, and a relay electrode 23 that receives and transmits the power transmitted from the power transmission electrode 22 in a non-contact manner by an electric field coupling method. The power reception device 3 includes a power reception electrode 31 that receives the power transmitted from the relay electrode 23 in a non-contact manner by an electric field coupling method, and supplies the received power to the load 4.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a contactless power supply system that transmits power contactlessly by using an electric field coupling method, and a power transmission device used in the contactless power supply system. [Background technology]

[0002] In recent years, electric vehicles and unmanned, autonomous electric vehicles have attracted attention, and various research and development efforts have been conducted. To popularize these electric vehicles and electric vehicles, issues such as the cost and weight of the batteries they are equipped with, the length of their power supply time, the difficulty of recycling, and increased labor costs have become problems. Unmanned, contactless power supply technology is being considered as one method for solving these issues.

[0003] Such contactless power supply methods include, for example, spatial transmission, electric field coupling, and magnetic field coupling. Spatial transmission methods transmit power contactlessly by propagating electromagnetic waves between a transmitting antenna and a receiving antenna. Spatial transmission methods can transmit power over long distances, but they have the characteristics of low power receiving efficiency and low power handling capacity.

[0004] The electric field coupling method transmits power contactlessly by transmitting electric field energy through space via a capacitor formed between the power transmitting electrode and the power receiving electrode, while the magnetic field coupling method transmits power contactlessly by having the power transmitting coil and the power receiving coil operate like a transformer.

[0005] Compared to spatial transmission methods, electric field coupling and magnetic field coupling methods have the advantage of a short-distance power receiving range, while offering high power receiving efficiency and large amounts of power. For these reasons, they are attracting attention as the mainstream method for contactless power supply to electric cars and other electric vehicles. Among these methods, the electric field coupling method does not require the installation of expensive coils as in the magnetic field coupling method, making it possible to implement the method at low cost, and is therefore suitable for contactless power supply that requires power transmission equipment over a wide area (e.g., Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-63684 [Patent Document 2] Japanese Patent Application Publication No. 2017-163798 Summary of the Invention [Problem to be solved by the invention]

[0007] When power is supplied to a vehicle using a wireless power supply system using the electric field coupling method, a transmission line is buried in the road and a high-frequency power supply is connected to the transmission line by wire, as shown in Patent Documents 1 and 2. However, whether the high-frequency power supply is located above or below the floor, connection work to the transmission line is required, which has led to problems such as restrictions on the structure of the transmission line and difficulty in replacing the high-frequency power supply.

[0008] The present invention has been made to solve the above problems, and has an object to provide a contactless power supply system and a power transmission device that can improve the degree of freedom in installation. [Means for solving the problem]

[0009] In order to achieve this object, the contactless power supply system described in claim 1 supplies power to a load contactlessly, and includes a power transmitting device having a high-frequency power source that outputs high-frequency power, a power transmitting electrode that transmits the power output from the high-frequency power source, and a relay electrode that receives and transmits the power transmitted from the power transmitting electrode contactlessly by an electric field coupling method, and a power receiving device that has a power receiving electrode that receives the power transmitted from the relay electrode contactlessly by an electric field coupling method and supplies the received power to the load.

[0010] A contactless power supply system according to a second aspect of the present invention is the contactless power supply system according to the first aspect, wherein the relay electrode is fixed to a predetermined position.

[0011] A contactless power supply system according to a third aspect of the present invention is the contactless power supply system according to the first or second aspect, wherein the relay electrode is buried in a predetermined place.

[0012] The contactless power supply system of claim 4 is the contactless power supply system of any one of claims 1 to 3, wherein the relay electrode comprises a plurality of electrode plates, stacked so that at least some of the electrode plates face each other, and one of the electrode plates receives power transmitted from the power transmitting electrode, and another of the electrode plates transmits power to the power receiving electrode, and power is transmitted and received contactlessly between the adjacent electrode plates by an electric field coupling method.

[0013] The contactless power supply system of claim 5 is the contactless power supply system of any one of claims 1 to 4, wherein the relay electrode comprises a plurality of electrode plates, at least some of which are arranged in cascade so as not to face each other, one of the electrode plates receives power transmitted from the power transmitting electrode, and another of the electrode plates transmits power to the power receiving electrode, and power is transmitted and received contactlessly between adjacent electrode plates by an electric field coupling method.

[0014] The power transmission device described in claim 6 transmits power contactlessly using an electric field coupling method to a power receiving device that has a power receiving electrode that receives power and supplies the received power to a load, and includes a high-frequency power source that outputs high-frequency power, a power transmission electrode that transmits the power output from the high-frequency power source, and a relay electrode that receives and transmits the power transmitted from the power transmission electrode contactlessly using an electric field coupling method. [Effects of the Invention]

[0015] According to the contactless power supply system of claim 1, in the power transmitting device, high-frequency power output from the high-frequency power source is transmitted and received contactlessly from the power transmitting electrode to the relay electrode using electric field coupling. Then, the power received at the relay electrode is transmitted and received contactlessly from the relay electrode to the power receiving electrode of the power receiving device using electric field coupling. The power receiving device supplies the power received by its power receiving electrode to a load. In this way, power is transmitted contactlessly from the power transmitting electrode to the relay electrode, which transmits power to the power receiving electrode of the power receiving device, using electric field coupling. This prevents the installation location of the high-frequency power source from being limited by the position of the relay electrode. Furthermore, contactless power supply using electric field coupling minimizes a decrease in transmission efficiency even if there is a slight misalignment between the electrodes that transmit and receive power. This has the effect of improving installation flexibility.

[0016] The contactless power supply system according to claim 2 has the following effect in addition to the effect of the contactless power supply system according to claim 1. That is, even if the relay electrode is fixed at a predetermined position, the power output from the high frequency power supply is transmitted to the fixed relay electrode in a contactless manner by electric field coupling. This prevents the installation position of the high frequency power supply from being limited by the position of the fixed relay electrode, thereby improving the degree of freedom in installation.

[0017] The contactless power supply system of claim 3 achieves the following effect in addition to the effect achieved by the contactless power supply system of claim 1 or 2. That is, even if the relay electrode is buried in a predetermined location, power output from the high-frequency power source is transmitted to the buried relay electrode in a contactless manner using an electric field coupling method. This prevents the installation location of the high-frequency power source from being limited by the location of the buried relay electrode. Furthermore, since the buried location makes it difficult to determine the location of the relay electrode, even if there is a slight misalignment between the electrodes, the decrease in transmission efficiency can be minimized. This has the effect of improving the degree of freedom in installation. Furthermore, there is no need to perform construction work to connect wiring from the high-frequency power source to the buried relay electrode, which has the effect of reducing installation costs.

[0018] The contactless power transfer system of claim 4 achieves the following effect in addition to the effect achieved by the contactless power transfer system of any one of claims 1 to 3. Specifically, the relay electrode is composed of multiple electrode plates, and at least some of the electrode plates are stacked so as to face each other. One of the electrode plates receives power transmitted from the power transmitting electrode, and another of the electrode plates transmits power to the power receiving electrode. Furthermore, power is transmitted and received contactlessly between adjacent electrode plates using an electric field coupling system. Since the relay electrode is thus configured by stacking at least some of the multiple electrode plates, even when the high-frequency power source of the power transmitting device is located far from the load, power output from the high-frequency power source can be transmitted to the power receiving electrode via the multiple electrode plates and supplied to the load. Furthermore, because power is transmitted and received via the electric field coupling system, transmission and reception via the multiple electrode plates minimizes a decrease in transmission efficiency even if the electrodes are slightly misaligned. This has the effect of improving installation flexibility.

[0019] The contactless power transfer system of claim 5 achieves the following effect in addition to the effect achieved by the contactless power transfer system of any one of claims 1 to 4. Specifically, the relay electrode is composed of multiple electrode plates, and at least some of the electrode plates are cascade-connected so as not to face each other. One of the electrode plates receives power transmitted from the power transmitting electrode, and another of the electrode plates transmits power to the power receiving electrode. Furthermore, power is transmitted and received contactlessly between adjacent electrode plates using an electric field coupling system. By cascade-connecting at least some of the multiple electrode plates in the relay electrode, even when the high-frequency power source of the power transmitting device is located far from the load, power output from the high-frequency power source can be transmitted to the power receiving electrode via the multiple electrode plates and supplied to the load. Furthermore, because power is transmitted and received via an electric field coupling system, transmission and reception via multiple electrode plates minimizes a decrease in transmission efficiency even if the electrodes are slightly misaligned. This has the effect of improving installation flexibility.

[0020] According to the power transmitting device of claim 6, high-frequency power output from the high-frequency power source is transmitted and received contactlessly from the power transmitting electrode to the relay electrode using electric field coupling. Then, the power received at the relay electrode is transmitted and received contactlessly from the relay electrode of the power transmitting device to the power receiving electrode using electric field coupling. The power receiving device supplies the power received by its power receiving electrode to a load. Since power is thus transmitted contactlessly from the power transmitting electrode to the relay electrode that transmits power to the power receiving electrode of the power receiving device using electric field coupling, the installation location of the high-frequency power source is not limited by the location of the relay electrode. Furthermore, contactless power supply using electric field coupling minimizes a decrease in transmission efficiency even if there is a slight misalignment between the electrodes that transmit and receive power. This has the effect of improving installation flexibility. [Brief explanation of the drawings]

[0021] [Figure 1]1 is a schematic front view of a contactless power supply system according to a first embodiment of the present invention. [Figure 2] (a) is an equivalent circuit diagram used in the circuit simulation of the contactless power transfer system, and (b) is a diagram showing the S-parameter characteristics of power versus frequency obtained by the circuit simulation. [Figure 3] (a) is a photograph of the wireless power transfer system constructed for the demonstration, and (b) is a graph showing the DC-DC conversion efficiency characteristics versus load resistance obtained from the demonstration experiment. [Figure 4] FIG. 6 is a schematic front view of a contactless power supply system according to a second embodiment of the present invention. [Figure 5] FIG. 10 is a schematic front view of a contactless power supply system according to a third embodiment of the present invention. [Figure 6] FIG. 10 is a schematic front view of a contactless power supply system according to a fourth embodiment of the present invention. [Figure 7] FIG. 10 is a schematic front view of a contactless power supply system according to a fifth embodiment of the present invention. [Figure 8] FIG. 10 is a schematic front view of a contactless power supply system according to a sixth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Each of the embodiments described below illustrates a preferred specific example of the present invention. Therefore, the numerical values, shapes, materials, components, component placement and connection configurations, etc., shown in the following embodiments are merely examples and are not intended to limit the present invention. Therefore, among the components in the following embodiments, components that are not recited in the independent claims that represent the highest concept of the present invention will be described as optional components. Furthermore, in each drawing, substantially identical components are assigned the same reference numerals, and redundant explanations will be omitted or simplified.

[0023] (First embodiment) First, a schematic configuration of a contactless power supply system 1 and a power transmitting device 2 according to a first embodiment of the present invention will be described with reference to Fig. 1 to Fig. 3. Fig. 1 is a schematic front view of the contactless power supply system 1.

[0024] The contactless power supply system 1 is a system that supplies power to a load 4 in a contactless (wireless) manner, and is composed of a power transmitting device 2 and a power receiving device 3. The load 4 may be, for example, a battery that stores the supplied power, or a device (such as a motor) that operates using the supplied power.

[0025] The power transmitting device 2 is a device that transmits (transmits) electric power to the power receiving device 3 connected to the load 4 in a non-contact manner by an electric field coupling method, and includes at least a high-frequency power source 21, a power transmitting electrode 22, and a relay electrode 23.

[0026] The high-frequency power supply 21 is a high-frequency inverter that generates and outputs high-frequency power, and is connected by wire to the power transmitting electrode 22 via a matching circuit (not shown). The matching circuit is a circuit that matches the output impedance of the high-frequency power supply 21 with the input impedance to the high-frequency power supply 21.

[0027] The high-frequency power source 21 and the matching circuit and / or the power transmitting electrode 22 may be integrated, for example, by incorporating the matching circuit and / or the power transmitting electrode 22 into the high-frequency power source 21. Furthermore, if the output impedance of the high-frequency power source 21 and the input impedance to the high-frequency power source 21 are matched, the matching circuit may be omitted.

[0028] The power transmitting electrode 22 is provided so as to form an electric field coupler (capacitor) with the relay electrode 23, and is an electrode for transmitting the power output from the high frequency power supply 21 to the relay electrode 23.

[0029] The relay electrode 23 is fixedly installed in a buried state under the floor 10 (or under the road), and is an electrode that receives the power transmitted from the power transmitting electrode 22 in a non-contact manner by an electric field coupling method using an electric field coupler (capacitor) formed between the power transmitting electrode 22 and the relay electrode 23. The relay electrode 23 is also an electrode that transmits (transmits) power to the power receiving electrode 31 in a non-contact manner by an electric field coupling method using an electric field coupler (capacitor) formed between the relay electrode 23 and the power receiving electrode 31, as will be described later.

[0030] In the contactless power supply system 1 according to the first embodiment, the high-frequency power supply 21 and the power transmission electrode 22 are not provided under the floor 10 where the relay electrode 23 is provided, but are provided above the floor surface (or the ground).

[0031] Next, the power receiving device 3 is a device that receives (receives) the power transmitted (transmitted) from the power transmitting device 2 and supplies the received power to the load 4, and is installed above the floor together with the load 4. The power receiving device 3 has at least a power receiving electrode 31. Note that the power receiving device 3 and the load 4 may be configured as one unit, for example, the power receiving device 3 may be built into the load 4.

[0032] The power receiving electrode 31 is an electrode provided so as to form an electric field coupler (capacitor) with the relay electrode 23, and receives (receives) the power transmitted from the relay electrode 23 in a non-contact manner by an electric field coupling method using the electric field coupler (capacitor) formed between the relay electrode 23 and the power receiving electrode 31. The power receiving electrode 31 is connected by wire to the load 4 via a matching circuit (not shown) and, if necessary, a rectifier circuit (not shown).

[0033] Here, the matching circuit is a circuit that controls the output impedance of the load 4 and the input impedance of the load 4. The rectifier circuit is a circuit that rectifies the high-frequency power output from the power-receiving electrode 31 into DC. For example, if the load 4 is a DC motor, the DC motor is driven by the power rectified into DC by the rectifier circuit. If the load 4 is a battery, the power rectified into DC by the rectifier circuit is supplied to the battery, and the battery is charged.

[0034] Next, a description will be given of the operation of the contactless power supply system 1 configured as above. In the contactless power supply system 1, when high-frequency power is generated by the high-frequency power supply 21 in the power transmission device 2, the power is output to the power transmission electrode 22 via a matching circuit (not shown). The power output to the power transmission electrode 22 is transmitted (transmitted) to the relay electrode 23 in a contactless manner by an electric field coupling method.

[0035] When the relay electrode 23 receives (receives) the power transmitted from the power transmitting electrode 22, it transmits (transmits) the received power to the power receiving electrode 31 of the power receiving device 3 in a contactless manner using electric field coupling. The power receiving device 3 receives (receives) the power transmitted from the relay electrode 23 via the power receiving electrode 31. The power receiving device 3 then supplies the power received by the power receiving electrode 31 to the load 4.

[0036] Here, the power transmission efficiency of the contactless power transfer system 1 will be described with reference to Fig. 2 and Fig. 3. First, in Fig. 2, the power transmission efficiency of the contactless power transfer system 1 was analyzed by a circuit simulation using an equivalent circuit of the contactless power transfer system 1. Here, Fig. 2(a) is an equivalent circuit diagram used in the circuit simulation, and Fig. 2(b) is a diagram showing the S-parameter characteristics of power versus frequency obtained by the circuit simulation.

[0037] 2(a), the circuit diagram used for the circuit simulation of the contactless power transfer system 1 has the output impedance of the high-frequency power supply 21 set to a resistance of 50 Ω, and the load 4 set to a resistance of 50 Ω. In this circuit diagram, a matching circuit on the power transmitting device 2 side, an electric field coupler formed by the power transmitting electrode 22 and the relay electrode 23, an electric field coupler formed by the relay electrode 23 and the power receiving electrode 31, and a matching circuit on the power receiving device 3 side are connected in cascade between the high-frequency power supply 21 and the load 4.

[0038] In the matching circuit on the power transmission device 2 side, a series-connected inductor L1 (6.86 μH) and resistor R1 (4 Ω) are connected in parallel to the high-frequency power supply 21, and an inductor L2 (6.93 μH) and resistor R2 (4 Ω) are connected in series at one end of the high-frequency power supply 21 on the downstream side of the parallel connection (the electric field coupler side formed by the power transmission electrode 22 and the relay electrode 23). Note that the values ​​in parentheses are the inductance or resistance values ​​of the respective elements used in the circuit simulation (the same applies to the following description of FIG. 2(a)).

[0039] In the electric field coupler consisting of the power transmission electrode 22 and the relay electrode 23, capacitors C1 and C3 of 20 pF are connected in parallel with the high-frequency power supply 21 as self-capacitance, and a capacitor C2 of 60 pF is used as mutual capacitance, connected in series between the connection points of the capacitors C1 and C3 on one end side of the high-frequency power supply 21.

[0040] In the electric field coupler consisting of the relay electrode 23 and the receiving electrode 31, capacitors C4 and C6 of 20 pF are connected in parallel with the high-frequency power supply 21 as self-capacitance, and a capacitor C5 of 60 pF is used as mutual capacitance, connected in series between the connection points of the capacitors C4 and C6 on one end side of the high-frequency power supply 21.

[0041] In the matching circuit on the power receiving device 3 side, a series-connected inductor L4 (10.73 μH) and resistor R4 (4 Ω) are connected in parallel with the high-frequency power supply 21, and an inductor L3 (9.68 μH) and resistor R3 (4 Ω) are connected in series on the upstream side of the parallel connection (the electric field coupler side consisting of the relay electrode 23 and the power receiving electrode 31) at one end of the high-frequency power supply 21.

[0042] As a result of a circuit simulation using the equivalent circuit shown in Figure 2(a), the frequency characteristics of the S parameters shown in Figure 2(b) were obtained. That is, of the S parameters, S11, which indicates the power reflection loss on the high-frequency power supply 21 side, and S21, which indicates the power insertion loss (transmittance) from the high-frequency power supply 21 to the load 4, showed the best values ​​around a frequency of 6.78 MHz. That is, by setting the power frequency to 6.78 MHz, it is possible to minimize the power reflection loss while achieving a good power transmittance of 90%.

[0043] 6.78 MHz is a frequency in the ISM band that is expected to be used for contactless power transmission. The results of this circuit simulation show that, instead of the conventional configuration in which power output from high-frequency power supply 21 is supplied to relay electrode 23 via a wire, power can be transmitted to load 4 efficiently even if it is transmitted contactlessly from power transmitting electrode 22 to relay electrode 23 using electric field coupling.

[0044] Next, demonstration of the contactless power supply system 1 according to the first embodiment will be described with reference to Fig. 3. Fig. 3(a) is a photograph of the contactless power supply system 1 actually constructed for the demonstration, and Fig. 3(b) is a diagram showing the DC-DC conversion efficiency characteristics versus load resistance obtained from the demonstration experiment.

[0045] As shown in Figure 3(a), in this demonstration, a contactless power supply system 1 was constructed in which power was supplied via a wire from a high-frequency power source 21 to a power transmitting electrode 22, power was transmitted contactlessly from the power transmitting electrode 22 to a relay electrode 23 using an electric field coupling method, power was transmitted contactlessly from the relay electrode 23 to a power receiving electrode 31 using an electric field coupling method, and the power received by the power receiving electrode 31 was supplied to a load 4 via a wire.

[0046] In this demonstration, an electronic load was used as the load 4, and the DC-DC conversion efficiency from the high-frequency power supply 21 to the load 4 was measured while varying the resistance value from 20 Ω to 1000 Ω. As a result, as shown in Figure 3(b), when the resistance value of the load 4 was 50 Ω to 100 Ω, the DC-DC conversion efficiency was 60% or more.

[0047] In the contactless power supply system 1, a load of 50 Ω is generally used as the load 4. Therefore, even if power output from the high-frequency power supply 21 is transmitted contactlessly from the power transmitting electrode 22 to the relay electrode 23 by an electric field coupling method instead of the conventional configuration in which the power is supplied to the relay electrode 23 by a wire, the power can be efficiently transmitted to the load 4.

[0048] The contactless power supply system 1 and the power transmission device 2 according to the first embodiment described above have the following advantages.

[0049] (a) In the power transmitting device 2, high-frequency power output from the high-frequency power supply 21 is transmitted and received contactlessly from the power transmitting electrode 22 to the relay electrode 23 by electric field coupling. Then, the power received at the relay electrode 23 is transmitted and received contactlessly from the relay electrode 23 to the power receiving electrode 31 of the power receiving device 3 by electric field coupling. The power receiving device 3 supplies the power received by its power receiving electrode 31 to the load 4.

[0050] In this way, power is supplied to the relay electrode 23, which transmits power to the power receiving electrode 31 of the power receiving device 3, not via a wire from the high-frequency power supply 21, but via a contactless method using electric field coupling from the power transmitting electrode 22 to the relay electrode 23. Even when power is supplied to the relay electrode 23 in this manner, power can be efficiently transmitted to the load 4. Furthermore, by supplying power from the power transmitting electrode 22 to the relay electrode 23 via electric field coupling in a contactless manner, the installation position of the high-frequency power supply 21 can be prevented from being limited by the position of the relay electrode 23.

[0051] In addition, it is known that in contactless power supply using magnetic field coupling with a coil, even a slight misalignment of the coil can cause a rapid drop in power transmission efficiency.In contrast, in contactless power supply using electric field coupling, the drop in transmission efficiency can be kept small even if there is a slight misalignment between the electrodes that transmit and receive power.

[0052] As described above, the contactless power supply system 1 and the power transmitting device 2 according to the first embodiment can improve the degree of freedom in installation.

[0053] (b) Even when the relay electrode 23 is fixed to the underfloor 10, the electric power output from the high frequency power supply 21 is transmitted to the fixed relay electrode 23 in a non-contact manner by the electric field coupling method. This prevents the installation position of the high frequency power supply 21 from being restricted by the position of the fixed relay electrode 23, thereby improving the degree of freedom in installation.

[0054] (c) Even if the relay electrode 23 is buried under the floor 10, the power output from the high-frequency power source 21 is transmitted to the buried relay electrode 23 in a non-contact manner using an electric field coupling method. This prevents the installation location of the high-frequency power source 21 from being limited by the position of the buried relay electrode 23. Furthermore, since the buried relay electrode 23 makes it difficult to determine its position, even if there is a slight misalignment between the power transmitting electrode 22 and the relay electrode 23, the decrease in transmission efficiency can be minimized. This improves the flexibility of installation. Furthermore, there is no need to perform construction work to connect wiring from the high-frequency power source 21 to the buried relay electrode 23, such as by digging up the floor 10, which further improves the flexibility of installation and also reduces the increase in installation costs.

[0055] (d) Because the high-frequency power source 21 and the power transmitting electrode 22 can be installed above the floor surface without being buried under the floor 10, their installation is less likely to be limited by the relay electrode 23 buried under the floor 10. This further increases the degree of freedom in installation. Furthermore, because the high-frequency power source 21 and the power transmitting electrode 22 are installed above the floor surface, maintenance and replacement of the high-frequency power source 21 and the power transmitting electrode 22 can be easily performed. Furthermore, construction work to bury the high-frequency power source 21 and the power transmitting electrode 22 under the floor 10, such as digging up the floor 10, is not required, which also reduces increases in installation costs.

[0056] (Second embodiment) Next, a schematic configuration of a contactless power supply system 1 and a power transmission device 2 according to a second embodiment of the present invention will be described with reference to Fig. 4. Fig. 4 is a schematic front view of the contactless power supply system 1. In Fig. 4, the same components as those in the contactless power supply system 1 and the power transmission device 2 according to the first embodiment are denoted by the same reference numerals, and description thereof will be omitted here.

[0057] The contactless power supply system 1 and the power transmission device 2 according to the second embodiment differ from the contactless power supply system 1 and the power transmission device 2 according to the first embodiment in the installation positions of the high-frequency power source 21 and the power transmission electrode 22 of the power transmission device 2. That is, in the first embodiment, the high-frequency power source 21 and the power transmission electrode 22 are installed above the floor surface (or road), but in the second embodiment, the high-frequency power source 21 and the power transmission electrode 22 are buried under the floor 10 (or under the road). Other configurations are the same as those in the first embodiment.

[0058] In the contactless power supply system 1 and the power transmitting device 2 according to the second embodiment, the high frequency power source 21 and the power transmitting electrode 22 are buried under the floor 10 (or under the road), but power is supplied to the relay electrode 23 that transmits power to the power receiving electrode 31 of the power receiving device 3 not by wire from the high frequency power source 21 but by electric field coupling from the power transmitting electrode 22 to the relay electrode 23 in a contactless manner, thereby preventing the installation position of the high frequency power source 21 from being limited by the position of the relay electrode 23. This improves the degree of freedom in installation.

[0059] In addition, the contactless power supply system 1 and the power transmission device 2 according to the second embodiment have the same configuration as the contactless power supply system 1 and the power transmission device 2 according to the first embodiment, and therefore have the same effects.

[0060] (Third embodiment) Next, a schematic configuration of a contactless power supply system 1 and a power transmission device 2 according to a third embodiment of the present invention will be described with reference to Fig. 5. Fig. 5 is a schematic front view of the contactless power supply system 1. In Fig. 5, the same components as those in the contactless power supply systems 1 and power transmission devices 2 according to the first and second embodiments are denoted by the same reference numerals, and description thereof will be omitted here.

[0061] The contactless power supply system 1 and the power transmission device 2 according to the third embodiment differ from the contactless power supply system 1 and the power transmission device 2 according to the second embodiment in the configuration of the relay electrode 23. That is, while the relay electrode 23 in the second embodiment is configured from a single electrode plate, in the third embodiment, the relay electrode 23 is configured from two electrode plates, a first relay electrode 231 and a second relay electrode 232, and these first relay electrode 231 and second relay electrode 232 are stacked so as to face each other. An electric field coupler (capacitor) is formed between the first relay electrode 231 and the second relay electrode 232. The first relay electrode 231 and the second relay electrode 232 constitute a relay electrode of the present invention. Note that the other configurations are the same as those in the second embodiment.

[0062] The first relay electrode 231 receives (receives) power transmitted (transmits) from the power transmitting electrode 22 in a contactless manner using electric field coupling, and also transmits (transmits) the received power to the second relay electrode 232 in a contactless manner using electric field coupling. Furthermore, the second relay electrode 232 receives (receives) power transmitted (transmits) from the first relay electrode 231 in a contactless manner using electric field coupling, and also transmits (transmits) the received power to the power receiving electrode 31 of the power receiving device 3 in a contactless manner using electric field coupling.

[0063] As described above, in the contactless power supply system 1 and the power transmitting device 2 according to the third embodiment, the relay electrode is configured by stacking the first relay electrode 231, the second relay electrode 232, and multiple electrode plates. Therefore, even if the position of the high-frequency power source 21 of the power transmitting device 2 is far from the position of the load 4, the power output from the high-frequency power source 21 can be transmitted to the power receiving electrode 31 via multiple electrode plates (the first relay electrode 231 and the second relay electrode 232) and supplied to the load 4. Furthermore, since power is transmitted and received using the electric field coupling method, power is transmitted and received via multiple electrode plates (the first relay electrode 231 and the second relay electrode 232). This minimizes the decrease in transmission efficiency even if there is some misalignment between the electrodes. This improves the flexibility of installation.

[0064] Additionally, the contactless power supply system 1 and the power transmission device 2 according to the third embodiment have the same configuration as the contactless power supply system 1 and the power transmission device 2 according to the first and second embodiments, and therefore have the same effects.

[0065] (Fourth embodiment) Next, a schematic configuration of a contactless power supply system 1 and a power transmission device 2 according to a fourth embodiment of the present invention will be described with reference to Fig. 6. Fig. 6 is a schematic front view of the contactless power supply system 1. In Fig. 6, the same components as those in the contactless power supply systems 1 and power transmission devices 2 according to the first to third embodiments are denoted by the same reference numerals, and description thereof will be omitted here.

[0066] The contactless power supply system 1 and the power transmission device 2 according to the fourth embodiment differ from the contactless power supply system 1 and the power transmission device 2 according to the first embodiment in the configuration of the relay electrode 23. That is, whereas the relay electrode 23 in the first embodiment is configured by a single electrode plate, the relay electrode 23 in the fourth embodiment is configured by two electrode plates, a first relay electrode 231 and a second relay electrode 232, which are cascade-connected and not opposed to each other. An electric field coupler is formed between the first relay electrode 231 and the second relay electrode 232. The first relay electrode 231 and the second relay electrode 232 constitute a relay electrode of the present invention. The other configurations are the same as those in the first embodiment.

[0067] The first relay electrode 231 receives (receives) power transmitted (transmits) from the power transmitting electrode 22 in a contactless manner using electric field coupling, and also transmits (transmits) the received power to the second relay electrode 232 in a contactless manner using electric field coupling. Furthermore, the second relay electrode 232 receives (receives) power transmitted (transmits) from the first relay electrode 231 in a contactless manner using electric field coupling, and also transmits (transmits) the received power to the power receiving electrode 31 of the power receiving device 3 in a contactless manner using electric field coupling.

[0068] As described above, in the contactless power supply system 1 and the power transmitting device 2 according to the fourth embodiment, the relay electrodes are configured by cascading the first relay electrode 231 and the second relay electrode 232 and a plurality of electrode plates. Therefore, even if the position of the high-frequency power source 21 of the power transmitting device 2 is far from the position of the power receiving electrode 31 of the power receiving device 3, or even if the position of the high-frequency power source 21 of the power transmitting device 2 is far from the position of the load 4, the power output from the high-frequency power source 21 can be transmitted to the power receiving electrode 31 via the plurality of electrode plates (the first relay electrode 231 and the second relay electrode 232) and supplied to the load 4. Furthermore, since power is transmitted and received by the electric field coupling method via the plurality of electrode plates (the first relay electrode 231 and the second relay electrode 232), even if there is some misalignment between the electrodes, the reduction in transmission efficiency can be minimized. This improves the flexibility of installation.

[0069] Additionally, the contactless power supply system 1 and the power transmission device 2 according to the fourth embodiment have the same configuration as the contactless power supply systems 1 and the power transmission devices 2 according to the first to third embodiments, and therefore have the same effects.

[0070] (Fifth embodiment) Next, a schematic configuration of a contactless power supply system 1 and a power transmission device 2 according to a fifth embodiment of the present invention will be described with reference to Fig. 7. Fig. 7 is a schematic front view of the contactless power supply system 1. In Fig. 7, the same components as those in the contactless power supply systems 1 and power transmission devices 2 according to the first to fourth embodiments are denoted by the same reference numerals, and description thereof will be omitted here.

[0071] The contactless power transfer system 1 and the power transmission device 2 according to the fifth embodiment differ from the contactless power transfer system 1 and the power transmission device 2 according to the first embodiment in their installation locations. In the first embodiment, the high-frequency power source 21 and the power transmission electrode 22 of the power transmission device 2 are provided above the floor, the relay electrode 23 of the power transmission device 2 is buried under the floor 10, and the power receiving device 3 and the load 4 are provided above the floor. In contrast, in the fifth embodiment, the relay electrode 23 is buried in the ceiling 11, the high-frequency power source 21 and the power transmission electrode 22 are provided above the ceiling, and the power receiving device 3 and the load 4 are provided inside a room or the like below the ceiling 11. Note that the high-frequency power source 21 and the power transmission electrode 22 may be provided inside a room or the like below the ceiling 11 instead of above the ceiling.

[0072] In this way, power is supplied to the relay electrode 23 that transmits power to the power receiving electrode 31 of the power receiving device 3 not by wire from the high frequency power source 21 but by contactlessly supplying power from the power transmitting electrode 22 to the relay electrode 23 by electric field coupling, thereby increasing the degree of freedom in the locations where the high frequency power source 21, the power transmitting electrode 22, the power receiving device 3, and the load 4 are installed, for example, while the relay electrode 23 is buried in the ceiling 11. This increases the degree of freedom in installation.

[0073] (Sixth embodiment) Next, a schematic configuration of a contactless power supply system 1 and a power transmission device 2 according to a sixth embodiment of the present invention will be described with reference to Fig. 8. Fig. 8 is a schematic front view of the contactless power supply system 1. In Fig. 8, the same components as those in the contactless power supply systems 1 and power transmission devices 2 according to the first to fifth embodiments are denoted by the same reference numerals, and description thereof will be omitted here.

[0074] The contactless power transfer system 1 and the power transmission device 2 according to the sixth embodiment differ from the contactless power transfer system 1 and the power transmission device 2 according to the first embodiment in their installation locations. In the first embodiment, the high-frequency power source 21 and the power transmission electrode 22 of the power transmission device 2 are provided above the floor, the relay electrode 23 of the power transmission device 2 is buried under the floor 10, and the power receiving device 3 and the load 4 are provided above the floor. In contrast, in the sixth embodiment, the relay electrode 23 is buried in the wall 12, the high-frequency power source 21 and the power transmission electrode 22 are provided in a room partitioned by the wall 12, and the power receiving device 3 and the load 4 are also provided in the room. Note that the high-frequency power source 21 and the power transmission electrode 22 may be provided in an adjacent room partitioned by the wall 12.

[0075] In this way, power is supplied to the relay electrode 23 that transmits power to the power receiving electrode 31 of the power receiving device 3 not by wire from the high-frequency power source 21 but by contactlessly supplying power from the power transmitting electrode 22 to the relay electrode 23 by electric field coupling, thereby increasing the degree of freedom in the locations where the high-frequency power source 21, the power transmitting electrode 22, the power receiving device 3, and the load 4 are installed, for example, while the relay electrode 23 is buried in the wall 12. This increases the degree of freedom in installation.

[0076] The present invention has been described above based on an embodiment, but the present invention is not limited to the above embodiment, and it can be easily inferred that various improvements and modifications are possible within the scope of the present invention.

[0077] For example, each embodiment may be modified by adding a part or parts of the configuration of another embodiment to that embodiment, or by replacing a part or parts of the configuration of that embodiment with that embodiment, etc. Furthermore, the numerical values ​​given in the above embodiments are merely examples, and it is of course possible to adopt other numerical values.

[0078] For example, in the third and fourth embodiments, the relay electrode has been described as being configured with two electrode plates, but it may be configured with three or more electrode plates. When configured with three or more electrode plates, power transmitted from the power transmitting electrode 22 is received by one electrode plate in a non-contact manner using electric field coupling, and power is transmitted from another electrode plate to the power receiving electrode 31 in a non-contact manner using electric field coupling, and power is transmitted and received between adjacent electrode plates in a non-contact manner using electric field coupling. As the number of electrode plates increases, even when the position of the high-frequency power source 21 of the power transmitting device 2 is farther from the position of the load 4, power output from the high-frequency power source 21 can be transmitted to the power receiving electrode 31 via multiple electrode plates and supplied to the load 4, thereby improving the degree of freedom in installation.

[0079] Furthermore, the third and fourth embodiments may be combined to form a relay electrode by stacking three or more electrode plates so that some of the electrode plates face each other and cascade-connecting the remaining electrode plates so that the remaining electrode plates do not face each other. This allows more freedom in determining the position of the high-frequency power source 21 of the power transmitting device 2 and the position of the load 4, further improving the degree of freedom in installation. [Explanation of symbols]

[0080] 1. Contactless power supply system 2. Power transmission equipment 3 Power receiving device 4. Load 21 High frequency power supply 22 Power transmission electrode 23 Relay electrode 31 Power receiving electrode

Claims

1. A wireless power supply system that supplies power to a load in a wireless manner, a power transmitting device including a high frequency power source that outputs high frequency power, a power transmitting electrode that transmits the power output from the high frequency power source, and a relay electrode that receives and transmits the power transmitted from the power transmitting electrode in a non-contact manner by an electric field coupling method; a power receiving device including a power receiving electrode that receives the power transmitted from the relay electrode in a non-contact manner by an electric field coupling method and that supplies the received power to the load; A contactless power supply system comprising:

2. 2. The contactless power supply system according to claim 1, wherein the relay electrode is fixed to a predetermined position.

3. 3. The contactless power supply system according to claim 1, wherein the relay electrode is buried in a predetermined location.

4. the relay electrode includes a plurality of electrode plates, which are stacked such that at least some of the electrode plates face each other; One of the electrode plates receives the power transmitted from the power transmitting electrode, power is transmitted from another one of the electrode plates to the power receiving electrode; 4. The contactless power supply system according to claim 1, wherein power is transmitted and received contactlessly between the adjacent electrode plates by an electric field coupling method.

5. the relay electrode includes a plurality of electrode plates, at least some of which are cascade-connected in parallel so as not to face each other; One of the electrode plates receives the power transmitted from the power transmitting electrode, power is transmitted from another one of the electrode plates to the power receiving electrode; 5. The contactless power supply system according to claim 1, wherein power is transmitted and received contactlessly between the adjacent electrode plates by an electric field coupling method.

6. A power transmitting device that transmits power in a non-contact manner by an electric field coupling method to a power receiving device that has a power receiving electrode that receives power and supplies the received power to a load, a high frequency power supply that outputs high frequency power; a power transmitting electrode for transmitting the power output from the high frequency power supply; a relay electrode that receives and transmits the power transmitted from the power transmitting electrode in a non-contact manner using an electric field coupling method.

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