Wireless power supply system

Abstract

To provide a wireless power supply system 1 which satisfactorily supplies AC power output from an AC power supply 4 to an electric load 50 when a movable body 3 moves.SOLUTION: The wireless power feeding system 1 includes the matching circuit 30 disposed between the coupler 60 and the electric load 50, and the matching circuit 40 disposed between the AC power supply 4 and the coupler 60. The matching circuit 30 has an impedance that cancels the reactance Xl in the impedance Zl. The matching circuit 40 operates such that the impedance Zin on the matching circuit 40 side with respect to the AC power supply 4 is proportional to the resistance value R of the electric load 50. By changing the value of the current flowing from the AC power supply 4 to the electric load 50 in accordance with the change in the resistance value R, the power output from the AC power supply 4 is supplied to the electric load 50.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a wireless power supply system. [Background technology]

[0002] Conventionally, a wireless power supply system has been proposed that outputs AC power output from an AC power supply to an electrical load of a mobile body in a contactless manner by electric field coupling (see, for example, Patent Document 1). The wireless power supply system includes a pair of power transmitting electrodes that transmit the AC power output from the AC power supply, and a pair of power receiving electrodes that are electric field coupled to the pair of power transmitting electrodes and receive the AC power transmitted from the pair of power transmitting electrodes. The pair of power transmitting electrodes and the pair of power receiving electrodes form a coupler that constitutes a pair of capacitors. The wireless power supply system also includes a matching circuit that is disposed between the AC power supply and the coupler and that, together with the coupler, constitutes a transformer circuit that corresponds to an equivalent ideal transformer.

[0003] Here, when the power transmitting electrode and the power receiving electrode have the same shape, no parasitic inductance occurs in the power transmitting electrode, and the parasitic capacitance occurring in the power receiving electrode becomes the same. The impedance on the matching circuit side with respect to the AC power source is impedance Zin, and the resistance value of the electrical load is resistance R. The matching circuit operates to reduce the reactance component of the coupler's impedance and make impedance Zin proportional to the resistance value R of the electrical load. This allows the current flowing from the AC power source to the electrical load to change in accordance with changes in resistance R, thereby enabling power from the AC power source to be efficiently supplied to the electrical load. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-142336 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the wireless power feeding system, when AC power from an AC power source is supplied to an electrical load through a pair of power transmitting electrodes and a pair of power receiving electrodes while a mobile object is moving, the length of the power transmitting electrodes in the moving direction needs to be longer than the length of the power receiving electrodes in the moving direction. The length of the power transmitting electrodes in the moving direction is the length of the power receiving electrodes in the moving direction of the mobile object.

[0006] When the length of the power transmitting electrode in the moving direction is longer than the length of the power receiving electrode in the moving direction, the parasitic inductance occurring in the pair of power transmitting electrodes cannot be ignored. Furthermore, the parasitic capacitance occurring between the pair of power transmitting electrodes differs from the parasitic capacitance occurring between the pair of power receiving electrodes. In this case, the matching circuit cannot reduce the reactance in the coupler. As a result, the reactance in the coupler causes the voltage traveling wave from the AC power source to be reflected by the coupler. As a result, power cannot be effectively supplied from the AC power source to the electrical load.

[0007] In view of the above, an object of the present disclosure is to provide a wireless power supply system that satisfactorily supplies AC power output from an AC power source to an electrical load of a mobile body while the mobile body is moving. [Means for solving the problem]

[0008] According to one aspect of the present disclosure, a wireless power supply system includes: A wireless power supply system that supplies AC power output from an AC power source (4) to an electric load (50) mounted on a moving object (3) in a wireless manner when the moving object (3) moves within a predetermined area (2), a pair of power transmission electrodes (10a, 10b) arranged in a predetermined area and transmitting AC power output from an AC power supply; a pair of power receiving electrodes (20a, 20b) mounted on the moving body, configured to be coupled to the pair of power transmitting electrodes in an electric field to form a coupler (60) together with the pair of power transmitting electrodes, and receiving AC power output from the pair of power transmitting electrodes; a first matching circuit (30) disposed between the coupler and the electrical load; a second matching circuit (40) disposed between the AC power source and the coupler; The two terminals where the coupler and the second matching circuit are commonly connected are defined as two common connection terminals (73a, 73b), and when the two common connection terminals are open, the impedance on the coupler side with respect to the first matching circuit is defined as a first impedance (Zl). the first matching circuit has an impedance that cancels the reactance of the first impedance; The second matching circuit operates so that a second impedance (Zin) on the second matching circuit side with respect to the AC power supply is proportional to the resistance value (R) of the electrical load.

[0009] Therefore, the reactance of the first impedance is canceled by the first matching circuit. As a result, the second impedance is changed by the second matching circuit in proportion to the resistance value of the electrical load. As a result, the current flowing from the AC power supply to the electrical load is changed in accordance with the change in the resistance value of the electrical load, so that power can be supplied from the AC power supply to the electrical load. Therefore, it is possible to provide a wireless power supply system that can effectively supply AC power output from the AC power supply to the electrical load.

[0010] According to another aspect of the present disclosure, a wireless power supply system includes: A wireless power supply system that supplies AC power output from an AC power source (4) to an electric load (50) mounted on each of a plurality of moving bodies (3) in a wireless manner when the moving bodies (3) move within a predetermined area (2), a pair of power transmission electrodes (10a, 10b) arranged in a predetermined area and transmitting AC power output from an AC power supply; a pair of power receiving electrodes (20a, 20b) mounted on each of the plurality of moving bodies, each of which is electrically coupled to the pair of power transmitting electrodes to form a coupler (60) together with the pair of power transmitting electrodes, and which receives AC power output from the pair of power transmitting electrodes for each of the moving bodies; a first matching circuit (30) disposed between the coupler and an electrical load for each mobile object; a second matching circuit (40) disposed between the AC power source and the coupler; When the two terminals to which the coupler and the second matching circuit are commonly connected are defined as two common connection terminals (73a, 73b), and the impedance on the coupler side with respect to the first matching circuit of each moving body is defined as a first impedance (Zl1, Zl2, ... ZlM) for each moving body in a state where the two common connection terminals are open, the first matching circuit has an impedance for canceling the reactance of the first impedance for each moving object; When the combined resistance value (RG) is the combined resistance value of the resistance values ​​(R1, R2, RM) of the electrical loads of multiple mobile bodies, the second matching circuit operates so that the second impedance (Zin) on the second matching circuit side with respect to the AC power source is proportional to the combined resistance value.

[0011] Therefore, the reactance of the first impedance of each mobile object is canceled for each mobile object by the first matching circuit. As a result, the second impedance is changed in proportion to the combined resistance value of the multiple electrical loads by the second matching circuit. As a result, the current flowing from the AC power source to the multiple electrical loads is changed in accordance with the change in the combined resistance value, so that power from the AC power source can be supplied to the multiple electrical loads. Therefore, it is possible to provide a wireless power supply system that can effectively supply AC power output from the AC power source to the multiple electrical loads. The reference symbols in parentheses attached to each component indicate an example of the correspondence between the component and the specific components described in the embodiments described below. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram showing the overall configuration of a wireless power feeding system according to a first embodiment of the present disclosure, and is a diagram for assisting in the description of a pair of power transmitting electrodes, a pair of power receiving electrodes, and an electric circuit configuration of an electric load in a moving object. [Figure 2]FIG. 2 is a diagram showing the configuration of the wireless power feeding system according to the first embodiment of FIG. 1, and is a diagram for assisting in the description of a coupler composed of a pair of power transmitting electrodes and a pair of power receiving electrodes. [Figure 3] 3 is a diagram for assisting in the description of the circuit configuration of a coupler and a matching circuit in the wireless power feeding system according to the first embodiment of FIG. 2. FIG. [Figure 4] 1. FIG. 4 is a diagram for assisting in the description of the lengths in the movement direction of a pair of power transmitting electrodes and a pair of power receiving electrodes in the first embodiment of FIG. [Figure 5] 4 is a diagram for assisting in the explanation of the impedance on the coupler side with respect to the matching circuit, in the first embodiment of FIG. 3, in a state in which two common connection terminals on the AC power supply side of the coupler are open. FIG. [Figure 6] 4 is a diagram for assisting in explaining the circuit configuration of a matching circuit on the electrical load side with respect to the coupler in the first embodiment of FIG. 3, and explaining the impedance on the matching circuit side with respect to the electrical load. [Figure 7] 4 is a diagram for assisting in explaining the relationship between the first matching circuit, the coupler, and the connection body in the first embodiment of FIG. 3. FIG. [Figure 8] 8 is a diagram for assisting in explaining the relationship between the input and output of the connector in the first embodiment of FIG. 7. FIG. [Figure 9] 3 is a diagram for assisting in the description of the circuit configurations of two matching circuits and a coupler in the wireless power feeding system according to the first embodiment of FIG. 2. FIG. [Figure 10] 3 is a diagram showing a circuit configuration of a matching circuit configured using a π-type LC circuit in the wireless power feeding system of the first embodiment of FIG. 2. FIG. [Figure 11] 3 is a diagram showing a circuit configuration of a matching circuit configured using a T-type LC circuit in the wireless power feeding system of the first embodiment of FIG. 2. FIG. [Figure 12] FIG. 10 is a diagram for assisting in the description of a pair of power transmission electrodes and a capacitor connected to a terminal end of a wireless power feeding system according to a second embodiment of the present disclosure. [Figure 13]14 is a diagram for assisting in the description of the relationship between the voltage generated between a pair of power transmission electrodes and the start, center, and end of the pair of power transmission electrodes in the wireless power feeding system according to the second embodiment of FIG. 13. FIG. [Figure 14] 14 is a diagram for assisting in the description of the relationship between the voltage generated between a pair of power transmission electrodes and the start, center, and end of the pair of power transmission electrodes in a wireless power feeding system in a comparative example of the second embodiment of FIG. 13. FIG. [Figure 15] 10A and 10B are diagrams for assisting in the description of the configuration of a pair of power transmission electrodes in a wireless power feeding system according to a third embodiment of the present disclosure. [Figure 16] FIG. 16 is a diagram for assisting in the detailed description of the configuration of a pair of power transmission electrodes in the wireless power feeding system according to the third embodiment of FIG. 15, and is a diagram for assisting in the description of a plurality of power transmission electrode pairs and a plurality of voltage compensation circuits. [Figure 17] FIG. 16 is a diagram for assisting in the description of the impedance of a pair of power transmitting electrodes in a comparative example in the third embodiment of FIG. [Figure 18] 18A and 18B are diagrams for assisting in the explanation of impedances at a plurality of positions of a pair of power transmitting electrodes in the comparative example of FIG. 17. [Figure 19] FIG. 19 is a diagram showing phases at a plurality of positions of a pair of power transmission electrodes in the comparative example of FIG. 18, and is a Smith chart for explaining that the phase is delayed from the end to the start of the pair of power transmission electrodes. [Figure 20] 16A and 16B are diagrams for assisting in the description of the start and end points of the divided electrode portions that constitute a pair of power transmission electrodes in the third embodiment of FIG. 15. [Figure 21] FIG. 16 is a diagram illustrating a pair of power transmission electrodes according to the third embodiment of FIG. 15, in which one power transmission electrode pair is disposed between two other power transmission electrode pairs, and is a diagram for assisting in the description of impedances at a plurality of positions. [Figure 22] FIG. 16 is a diagram showing phases at a plurality of positions of a pair of power transmitting electrodes in the third embodiment of FIG. 15, and is a diagram showing a Smith chart for explaining that a voltage compensation circuit compensates for a phase delay caused by the power transmitting electrode pair. [Figure 23]16 is a diagram for explaining the relationship between the voltage generated between a pair of power transmission electrodes and the positions of the power transmission electrodes in the third embodiment of FIG. 15. FIG. [Figure 24] FIG. 11 is a diagram for assisting in the detailed description of the configuration of a pair of power transmission electrodes of a wireless power feeding system according to a fourth embodiment of the present disclosure, and is a diagram showing the circuit configuration of a voltage compensation circuit disposed between two pairs of power transmission electrodes. [Figure 25] FIG. 13 is a diagram for assisting in the detailed description of the configuration of a pair of power transmission electrodes of a wireless power feeding system according to a fifth embodiment of the present disclosure, and is a diagram showing the circuit configuration of a voltage compensation circuit disposed between two pairs of power transmission electrodes. [Figure 26] FIG. 13 is a diagram illustrating the overall configuration of a wireless power feeding system in which power is fed to multiple moving bodies while they are moving in a sixth embodiment of the present disclosure, and is a diagram for assisting in the explanation of a pair of power transmitting electrodes, a pair of power receiving electrodes, and electrical loads in the multiple moving bodies. [Figure 27] FIG. 27 is a diagram showing the circuit configuration of the wireless power feeding system in the sixth embodiment of FIG. 26, and is a diagram for assisting in the description of the circuit configuration of a coupler. [Figure 28] 27. FIG. 28 is a diagram showing the circuit configuration of the wireless power feeding system in the sixth embodiment of FIG. 26, and is a diagram for assisting in the description of the circuit configuration of the coupler in a state in which a plurality of parasitic inductances are removed from FIG. [Figure 29] FIG. 27 is a block diagram showing a circuit configuration of a wireless power feeding system in the sixth embodiment of FIG. 26. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following embodiments, identical or equivalent parts are denoted by the same reference numerals in the drawings to simplify the description.

[0014] (First embodiment) A wireless power feeding system 1 according to the first embodiment will be described with reference to Fig. 1, Fig. 2, Fig. 3, etc. Fig. 1 is a block diagram showing the overall configuration of the wireless power feeding system 1 according to the present embodiment, and Fig. 2 is a schematic diagram showing the overall configuration of the wireless power feeding system 1 according to the present embodiment. Fig. 3 is an electric circuit showing the overall configuration of the wireless power feeding system 1 according to the present embodiment. The wireless power feeding system 1 according to the present embodiment wirelessly supplies AC power output from an AC power source 4 to an electric load 50 of a mobile object 3 that moves within a predetermined area 2 on a factory floor.

[0015] The mobile object 3 may be, for example, a robot that moves on the floor of a factory. The AC power source 4 is a high-frequency AC power source that outputs a high-frequency AC voltage with a constant peak value from power electrodes 4a and 4b. The AC voltage has a frequency of, for example, several MHz. The AC power source 4 is placed on, for example, the floor of a factory. As shown in FIGS. 1, 2, and 3, the wireless power feeding system 1 includes the AC power source 4, as well as power transmitting electrodes 10a and 10b, power receiving electrodes 20a and 20b, matching circuits 30 and 40, and an electrical load 50.

[0016] The power transmitting electrodes 10a, 10b are a pair of power transmitting electrodes that transmit high-frequency power output from the AC power supply 4 to the power receiving electrodes 20a, 20b in a non-contact manner. The power transmitting electrode 10a is a first power transmitting electrode connected to the power supply electrode 4a of the AC power supply 4. The power transmitting electrode 10b is a second power transmitting electrode connected to the power supply electrode 4b of the AC power supply 4. The power transmitting electrodes 10a, 10b are a pair of power transmitting electrodes that are arranged in a predetermined area 2 on the floor of a factory. The power transmitting electrodes 10a, 10b are each, for example, two conductive members formed in the shape of long plates that extend straight in the movement direction Ya of the mobile object 3.

[0017] The power transmitting electrodes 10a and 10b are arranged in parallel with a gap between them. The power transmitting electrodes 10a and 10b are each made of a conductive metal material such as iron, copper, or aluminum. In this embodiment, the end of the power transmitting electrode 10a that faces the power electrode 4a of the AC power source 4 is referred to as a starting end 11a, and the end of the power transmitting electrode 10b that faces the power electrode 4b of the AC power source 4 is referred to as a starting end 11b. The end of the power transmitting electrode 10a that is opposite the power electrode 4a of the AC power source 4 is referred to as a terminal end 12a, and the end of the power transmitting electrode 10b that is opposite the power electrode 4b of the AC power source 4 is referred to as a terminal end 12b.

[0018] 4, the length of each of the power transmitting electrodes 10a and 10b in the movement direction Ya of the moving object 3 is defined as a power transmitting electrode length Ma, and the length of each of the power receiving electrodes 20a and 20b in the movement direction Ya of the moving object 3 is defined as a power receiving electrode length Mb. The power transmitting electrodes 10a and 10b have the same power transmitting electrode length Ma. Furthermore, the power receiving electrodes 20a and 20b have the same power receiving electrode length Mb.

[0019] In this embodiment, the power transmitting electrode length Ma of the power transmitting electrodes 10a, 10b is longer than the power receiving electrode length Mb of the power receiving electrodes 20a, 20b. Note that, for convenience of explanation, the wavelength of the AC voltage output from the AC power supply 4 is defined as λ, and the value obtained by dividing λ by 4 is defined as Mq, as shown in Equation 1. The power transmitting electrode length Ma of each of the power transmitting electrodes 10a, 10b is set to be equal to or less than Mq.

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[0020] The power receiving electrodes 20a, 20b are arranged on the moving body 3. The power receiving electrodes 20a, 20b are each formed in the shape of a long plate extending straight in a predetermined direction. The power receiving electrodes 20a, 20b are arranged parallel to each other with a gap between them. The power receiving electrode 20a is connected to a load electrode 50a of the electric load 50. The power receiving electrode 20b is connected to a load electrode 50b of the electric load 50.

[0021] The power receiving electrode 20a is arranged so as to face the power transmitting electrode 10a across the air and be parallel to the power transmitting electrode 10a when the mobile object 3 moves along the power transmitting electrodes 10a, 10b relative to the power transmitting electrodes 10a, 10b. The power receiving electrode 20b is arranged so as to face the power transmitting electrode 10b across the air and be parallel to the power transmitting electrode 10b when the mobile object 3 moves along the power transmitting electrodes 10a, 10b. The power receiving electrodes 20a, 20b, together with the power transmitting electrodes 10a, 10b, form a pair of power receiving electrodes that constitute a coupler 60 that is electric field coupled to the power transmitting electrodes 10a, 10b.

[0022] As shown in Fig. 3, the coupler 60 includes parasitic inductances 61 and 62, capacitors 63 and 64, and parasitic capacitances 65 and 66. Capacitor 63 is formed by the power transmitting electrode 10a and the power receiving electrode 20a. Capacitor 63 uses the air between the power transmitting electrode 10a and the power receiving electrode 20a as its dielectric. Capacitor 64 is formed by the power transmitting electrode 10b and the power receiving electrode 20b. Capacitor 64 uses the air between the power transmitting electrode 10b and the power receiving electrode 20b as its dielectric.

[0023] Parasitic inductance 61 is an inductance formed in the current path of power transmitting electrode 10a through which AC current flows between the AC power source 4 and power receiving electrode 20a. Parasitic inductance 62 is an inductance formed in the current path of power transmitting electrode 10b through which AC current flows between the AC power source 4 and power receiving electrode 20b. Parasitic capacitance 65 is electrostatic capacitance formed between power transmitting electrodes 10a and 10b. Parasitic capacitance 66 is electrostatic capacitance formed between power receiving electrodes 20a and 20b.

[0024] The matching circuit 30 is a first matching circuit disposed in the mobile object 3. The matching circuit 30 is disposed between the coupler 60 and the electrical load 50. The matching circuit 30 and the coupler 60 are commonly connected to common connection terminals 70a and 70b, and an imaginary line connecting the common connection terminals 70a and 70b is an observation line 70c. In this embodiment, the impedance of the wireless power feeding system 1 viewed from the coupler 60 side with respect to the observation line 70c with the common connection terminals 73a and 73b open is defined as impedance Zl. In other words, the impedance Zl is the impedance on the coupler 60 side with respect to the matching circuit 30 with the common connection terminals 73a and 73b open (i.e., the first impedance).

[0025] The matching circuit 30 includes an inductor 31 and an inductor 32. The inductor 31 is disposed between the capacitor 63 and the load electrode 50a of the electric load 50. The inductor 32 is disposed between the capacitor 64 and the load electrode 50b of the electric load 50. In this embodiment, the inductance La of the inductor 31 and the inductance Lb of the inductor 32 are set so as to cancel the reactance jXI of the impedance Zl, as will be described later.

[0026] Furthermore, matching circuit 40 is a four-terminal circuit arranged between AC power supply 4 and coupler 60. Matching circuit 40 is arranged on the factory floor. Hereinafter, the terminals to which matching circuit 40 and AC power supply 4 are commonly connected will be referred to as common connection terminals 71a and 71b. The imaginary line connecting common connection terminals 71a and 71b will be referred to as observation line 71c. The terminals to which matching circuit 40 and coupler 60 are commonly connected will be referred to as common connection terminals 73a and 73b, and the imaginary line connecting common connection terminals 73a and 73b will be referred to as observation line 73c.

[0027] In this embodiment, the impedance on the coupler 60 side with respect to the observation line 71c in the wireless power feeding system 1 is defined as impedance Zin. That is, the impedance Zin is the input impedance (i.e., second impedance) on the coupler 60 side with respect to the AC power supply 4. The matching circuit 40 is a second matching circuit that operates so that the impedance Zin changes in proportion to the resistance value R of the electrical load 50, as will be described later.

[0028] The electric load 50 is mounted on the mobile object 3. As shown in FIG. 1 , the electric load 50 includes a rectifier circuit 51, a charger 52, and a battery 53. The rectifier circuit 51 rectifies the AC voltage received from the power receiving electrodes 20a, 20b through the matching circuit 30. The charger 52 stores power in the battery 53 based on the rectified voltage rectified by the rectifier circuit 51. The battery 53 is a secondary battery that stores power charged by the charger 52 and supplies power to each electrical device in the mobile object 3.

[0029] 3, terminals to which the rectifier circuit 51 and the matching circuit 30 are commonly connected are referred to as common connection terminals 72a and 72b. An imaginary line connecting the common connection terminals 72a and 72b is referred to as an observation line 72c. Furthermore, the impedance of the wireless power feeding system 1 on the matching circuit 30 side with respect to the observation line 72c is referred to as impedance Zr. In this embodiment, the impedance of the wireless power feeding system 1 on the electrical load 50 side with respect to the observation line 72c is referred to as resistance R. That is, the impedance of the electrical load 50 has resistance R.

[0030] Next, specific examples of the matching circuit 30 and the coupler 60 in this embodiment will be described with reference to FIGS. 5, 6, 7, and 8. FIG. 5 is a diagram showing the coupler 60 in FIGS. 1, 2, and 3 expressed by a Z matrix [Zc]. [Zc] is expressed by Z parameters such as Z11, Z12, Z21, and Z22, as shown in Equation 2. Z11, Z12, Z21, and Z22 are obtained, for example, from the results of an electromagnetic field simulation that reflects the structure of the coupler 60. Z11, Z12, Z21, and Z22 contain information on parasitic inductances 61 and 62, capacitors 63 and 64, and parasitic capacitances 65 and 66, respectively.

[0031]

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[0032] In this embodiment, Rl in Equation 3 is the real part of impedance Zl, as shown in Equation 4. That is, Rl is the resistance component of impedance Zl. More specifically, Rl is the real part of Z22. Furthermore, Xl in Equation 3 is the imaginary part of impedance Zl, as shown in Equation 5. Xl is the reactance component of impedance Zl. More specifically, Xl is the imaginary part of Z22.

[0033]

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[0034] If the AC power source 4 and matching circuit 40 are omitted, the circuit 1a on the matching circuit 30 side of the observation line 72c in the wireless power supply system 1 will look like that shown in FIG. 6. In the circuit 1a in FIG. 6, the common connection terminals 73a and 73b are open. Since Xl is less than zero, -Xl is greater than zero. Therefore, the impedance of the connection body in which the inductors 31 and 32 are connected in series becomes equal to the impedance Zl. If the frequency of the AC power source 4 is f and the angular frequency of the AC power source 4 is ω, then ω is expressed as 2πf.

[0035] Using such ω, j (i.e., an imaginary number), ω, the inductance La of inductor 31, the inductance Lb of inductor 32, and Xl are expressed as shown in Expression 6. In addition, by modifying Expression 6, the inductance La of inductor 31, the inductance Lb of inductor 32, ω, and Xl have the relationship shown in Expression 7.

[0036]

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[0037]

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[0038]

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[0039]

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[0040] (π type LC circuit) First, a specific example of configuring a matching circuit 40 using a π-type LC circuit will be described with reference to Fig. 10. Fig. 10 is a diagram showing the circuit configuration of a matching circuit 40 configured using a π-type LC circuit. As shown in Fig. 10, the matching circuit 40 includes circuit elements 40a, 40b, 40c, and 40d.

[0041] Circuit element 40a is connected between common connection terminals 71a and 73a and has an impedance value obtained by dividing jX2 by 2. Circuit element 40b is connected between common connection terminals 71b and 73b and has an impedance value obtained by dividing jX2 by 2. Circuit element 40c is connected between common connection terminals 71a and 71b and has an impedance value of jX1. Circuit element 40d is connected between common connection terminals 73a and 73b and has an impedance value of jX3.

[0042] Furthermore, if the F matrix representing the relationship between the input voltage, input current, output voltage, and output current of matching circuit 40 in Fig. 10 is [Fπ], then this [Fπ] can be expressed by j, X1, X2, and X3, as shown in equation 15. Next, as shown in equations 16 and 17, jX1, jX2, and jX3 are found so that [Fπ] shown in equation 15 matches [Fs] shown in equation 14. In this way, jX1, jX2, and jX3 are found when matching circuit 40 is configured using a π-type LC circuit.

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[0043]

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[0044] Circuit element 41b is an element whose impedance is the value obtained by dividing jX1 by 2. Circuit element 41d is an element whose impedance is the value obtained by dividing jX3 by 2. Circuit element 41e is connected between common connection terminal 42a of circuit elements 41a and 41c and common connection terminal 42b of circuit elements 41b and 41d. Circuit element 41e is an element whose impedance is jX2. Common connection terminal 42a is a terminal to which circuit elements 41a and 41c are commonly connected. Common connection terminal 42b is a terminal to which circuit elements 41b and 41d are commonly connected.

[0045] 11 is expressed as [FT], this [FT] can be expressed by j, X1, X2, and X3 as shown in Expression 21. Next, as shown in Expressions 22 and 23, jX1, jX2, and jX3 are found so that [FT] shown in Expression 21 matches [Fs] shown in Expression 14.

[0046]

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[0047]

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[0048]

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[0049] In this case, as shown in Equation 32, the value of C3 is found by assuming that the value obtained by dividing 1 by ωC3 is equal to -X3. As described above, L1 or C1 is found based on the value of X1. L2 or C2 is found based on the value of X2. L3 or C3 is found based on the value of X3. Therefore, the constants of circuit elements 40a, 40b, 40c, and 40d of matching circuit 40 in FIG. 10 can be set using any of L1 to L3 or C1 to C3. Alternatively, the constants of circuit elements 41a, 41b, 41c, 41d, and 41e of matching circuit 40 in FIG. 11 can be set using any of L1 to L3 or C1 to C3.

[0050]

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[0051] First, the mobile object 3 moves along the power transmitting electrodes 10a and 10b in a predetermined area 2 on the factory floor with the power receiving electrode 20a facing the power transmitting electrode 10a and the power receiving electrode 20b facing the power transmitting electrode 10b. That is, the mobile object 3 moves relative to the power transmitting electrodes 10a and 10b in the predetermined area 2 with the power transmitting electrodes 10a and 10b being electric field coupled to the power receiving electrodes 20a and 20b. Here, the output voltage output from the AC power source 4 is applied to the rectifier circuit 51 through the matching circuit 40, the coupler 60, and the matching circuit 30.

[0052] Then, the rectifier circuit 51 rectifies the AC voltage provided from the AC power supply 4 through the matching circuit 40, the coupler 60, and the matching circuit 30, and provides the rectified voltage to the charger 52. The charger 52 charges the battery 53 based on the output voltage of the rectifier circuit 51. The matching circuit 30 operates to cancel the reactance in the impedance Zl. As a result, the impedance Zr becomes the resistance value (i.e., Rl) other than the reactance in the impedance Zl.

[0053] At this time, the matching circuit 40 operates so that the impedance Zin changes in proportion to the resistance value R of the electrical load 50. At this time, the resistance value R of the electrical load 50 changes depending on the state of charge of the battery 53. The AC power supply 4 changes the AC current flowing from the AC power supply 4 to the electrical load 50 side in accordance with the change in the resistance value R. Accordingly, the output power output from the AC power supply 4 is supplied to the electrical load 50 through the coupler 60 while suppressing changes in the peak value of the AC voltage output from the AC power supply 4.

[0054] According to the present embodiment described above, the wireless power feeding system 1 contactlessly supplies AC power output from the AC power source 4 to the electrical load 50 of the mobile object 3 when the mobile object 3 moves within a predetermined area 2 on a factory floor. The wireless power feeding system 1 is provided with a pair of power transmitting electrodes 10a, 10b that are arranged in the predetermined area 2 and transmit the AC power output from the AC power source 4. The wireless power feeding system 1 is provided with a pair of power receiving electrodes 20a, 20b that are mounted on the mobile object 3 and that are electric field coupled to the pair of power transmitting electrodes 10a, 10b to form a coupler 60 together with the pair of power transmitting electrodes 10a, 10b.

[0055] The power receiving electrodes 20a, 20b receive AC power output from the power transmitting electrodes 10a, 10b in a non-contact manner. The wireless power feeding system 1 includes a matching circuit 30 arranged between the coupler 60 and the electrical load 50, and a matching circuit 40 arranged between the AC power source 4 and the coupler 60. Two terminals to which the coupler 60 and the matching circuit 40 are commonly connected are referred to as common connection terminals 73a, 73b. When the common connection terminals 73a, 73b are open, the impedance on the coupler 60 side with respect to the matching circuit 30 is referred to as impedance Zl.

[0056] The matching circuit 30 has an impedance that cancels the reactance Xl of the impedance Zl. The matching circuit 40 operates so that the impedance Zin on the matching circuit 40 side with respect to the AC power supply 4 is proportional to the resistance value R of the electrical load 50. Therefore, the value of the current flowing from the AC power supply 4 to the electrical load 50 is changed in accordance with the change in the resistance value R, thereby supplying the electrical load 50 with the electrical power output from the AC power supply 4. Therefore, it is possible to provide a wireless power feeding system 1 that satisfactorily supplies the AC power output from the AC power supply 4 to the electrical load 50 while the mobile object 3 is moving.

[0057] The present embodiment configured as described above can achieve the following advantageous effects. That is, when the power transmitting electrode length Ma is longer than the power receiving electrode length Mb, the power transmitting electrode length Ma is equal to or less than Mq, which is the value obtained by dividing λ by 4. Therefore, compared to when the power transmitting electrode length Ma is greater than Mq, it is possible to suppress a decrease in the voltage value occurring between the power transmitting electrodes 10a, 10b. This allows power to be efficiently supplied from the power transmitting electrodes 10a, 10b to the power receiving electrodes 20a, 20b. Therefore, it is possible to efficiently supply power output from the AC power supply 4 to the electrical load 50 of the mobile object 3.

[0058] (Second embodiment) In the second embodiment, an example will be described in which a voltage standing wave occurs between the power transmitting electrodes 10a and 10b of the first embodiment, based on the output voltage of the AC power supply 4, and the voltage standing wave becomes a node at the terminals 12a and 12b. The wireless power feeding system 1 of this embodiment differs from the wireless power feeding system 1 of the first embodiment mainly in the power transmitting electrodes 10a and 10b.

[0059] In contrast, the following mainly describes the power transmitting electrodes 10a and 10b in the wireless power feeding system 1 of the second embodiment with reference to Fig. 12, Fig. 13, and Fig. 14. Fig. 12 is a schematic diagram showing the power transmitting electrodes 10a and 10b in the wireless power feeding system 1 of the present embodiment. As shown in Formula 33, when the division value obtained by dividing λ by 2 is set to a division value Mh, the power transmitting electrode length Ma of the power transmitting electrodes 10a and 10b is set to be equal to or less than the division value Mh.

number

[0060] For example, when the terminal ends 12a, 12b of the power transmitting electrodes 10a, 10b are open, antinodes of a voltage standing wave generated between the power transmitting electrodes 10a, 10b are generated at the terminal ends 12a, 12b, as shown in Fig. 13. The central portions 15a, 15b of the power transmitting electrodes 10a, 10b in the direction of movement Ya become nodes of the voltage standing wave. Therefore, when the power receiving electrodes 20a, 20b of the mobile object 3 face the central portions 15a, 15b of the power transmitting electrodes 10a, 10b, it becomes difficult to supply power from the power transmitting electrodes 10a, 10b to the power receiving electrodes 20a, 20b. In Fig. 13, the vertical axis represents the voltage VT1 between the power transmitting electrodes 10a, 10b, and the horizontal axis represents the position at the power transmitting electrodes 10a, 10b.

[0061] In contrast, in this embodiment, a capacitor 10c with a high capacitance is connected between the terminals 12a and 12b of the power transmitting electrodes 10a and 10b in Fig. 12. This reduces the impedance between the terminals 12a and 12b of the power transmitting electrodes 10a and 10b by the capacitor 10c. In this case, it can be considered that the terminals 12a and 12b are substantially short-circuited in the AC circuit. Therefore, nodes of the voltage standing wave between the power transmitting electrodes 10a and 10b are generated at the terminals 12a and 12b of the power transmitting electrodes 10a and 10b.

[0062] Accordingly, antinodes of a voltage standing wave between the power transmitting electrodes 10a and 10b occur at the central portions 15a and 15b of the power transmitting electrodes 10a and 10b, as shown in Fig. 14. In Fig. 14, the vertical axis represents the voltage VT2 of the power transmitting electrodes 10a and 10b, and the horizontal axis represents the position on the power transmitting electrodes 10a and 10b. Therefore, when the power receiving electrodes 20a and 20b of the moving object 3 face the central portions 15a and 15b of the power transmitting electrodes 10a and 10b, power can be effectively supplied from the power transmitting electrodes 10a and 10b to the power receiving electrodes 20a and 20b.

[0063] According to the present embodiment described above, the power transmitting electrode length Ma of the power transmitting electrodes 10a and 10b is longer than the power receiving electrode length Mb of the power receiving electrodes 20a and 20b. The power transmitting electrode length Ma is equal to or less than the value obtained by dividing λ by 2. λ is the wavelength of the traveling wave of the output voltage of the AC power supply 4. The capacitor 10c is connected between the terminal ends 12a and 12b of the power transmitting electrodes 10a and 10b. When a voltage standing wave is generated in the power transmitting electrodes 10a and 10b based on the voltage output from the AC power supply 4, the capacitor 10c operates to generate nodes of the voltage standing wave at the terminal ends 12a and 12b of the power transmitting electrodes 10a and 10b. Accordingly, antinodes of the voltage standing wave are generated at the central portions 15a and 15b of the power transmitting electrodes 10a and 10b. Therefore, when the power receiving electrodes 20a, 20b of the moving object 3 face the central portions 15a, 15b of the power transmitting electrodes 10a, 10b, power can be effectively supplied from the power transmitting electrodes 10a, 10b to the power receiving electrodes 20a, 20b.

[0064] (Third embodiment) In the first embodiment, an example in which the power transmitting electrodes 10a, 10b are configured using two conductive members has been described. However, instead of this, a third embodiment in which the power transmitting electrodes 10a, 10b are configured using a plurality of divided electrode portions for each power transmitting electrode will be described with reference to Figs. 15 to 23. Fig. 15 is a schematic diagram showing an outline of the power transmitting electrodes 10a, 10b of this embodiment. Fig. 16 is a diagram showing details of a portion XVI of the power transmitting electrodes 10a, 10b in Fig. 15.

[0065] As shown in Fig. 15, the power transmitting electrodes 10a and 10b of this embodiment each have a power transmitting electrode length Ma that is greater than Mq. As shown in Figs. 16 and 15, the power transmitting electrode 10a includes a plurality of divided electrode portions 13a. Each of the divided electrode portions 13a is a first divided electrode portion formed in the shape of an elongated plate extending in the movement direction Ya of the moving object 3. Each of the divided electrode portions 13a is made of a conductive metal material such as iron, copper, or aluminum.

[0066] The multiple divided electrode portions 13a are aligned in a line in the movement direction Ya of the moving object 3. The multiple divided electrode portions 13a each have a length in the movement direction Ya that is set to be less than Mq. The power transmitting electrode 10b includes multiple divided electrode portions 13b. Each of the multiple divided electrode portions 13b is a second divided electrode portion formed in the shape of an elongated plate that extends in the movement direction Ya of the moving object 3. Each of the multiple divided electrode portions 13b is made of a conductive metal material such as iron or copper. The multiple divided electrode portions 13b are aligned in a line in the movement direction Ya of the moving object 3. The multiple divided electrode portions 13b each have a length in the movement direction Ya that is set to be less than Mq.

[0067] Each of the plurality of split electrode portions 13a is arranged along a corresponding one of the plurality of split electrode portions 13b at a distance from the corresponding one of the plurality of split electrode portions 13b. Each of the plurality of split electrode portions 13a, together with a corresponding one of the plurality of split electrode portions 13b, constitutes a plurality of power transmitting electrode pairs 13c aligned in the movement direction Ya. The length of each of the plurality of power transmitting electrode pairs 13c in the movement direction Ya is set to be less than Mq.

[0068] In this embodiment, a voltage compensation circuit 14 that compensates for a phase delay (i.e., a phase lag) is provided between two adjacent power transmitting electrode pairs 13c among the multiple power transmitting electrode pairs 13c, as will be described later. The phase is the phase of the AC current relative to the AC voltage. The phase is determined by the impedance of the power transmitting electrode pair 13c. The AC voltage is an AC voltage generated between the power transmitting electrode pair 13c based on the output voltage of the AC power supply 4. The AC current is an AC current that flows through the power transmitting electrode pair 13c based on the output voltage of the AC power supply 4.

[0069] As a result, power transmitting electrodes 10a and 10b are configured with multiple power transmitting electrode pairs 13c and multiple voltage compensation circuits 14. Each of multiple voltage compensation circuits 14 is a left-handed circuit including capacitors 14a, 14b, 14c, and 14d and inductor 14e. Capacitors 14a and 14b are connected in series between two adjacent divided electrode portions 13a among multiple divided electrode portions 13a. Capacitors 14c and 14d are connected in series between two adjacent divided electrode portions 13b among multiple divided electrode portions 13b. Inductor 14e is connected between a common connection terminal of capacitors 14a and 14b and a common connection terminal of capacitors 14c and 14d. The common connection terminal of capacitors 14a and 14b is a terminal to which capacitors 14a and 14b are commonly connected.

[0070] The common connection terminal of the capacitors 14c and 14d is a terminal to which the capacitors 14c and 14d are commonly connected. If the inductance of the inductor 14e is L, L can be expressed by Equation 34. The capacitors 14a, 14b, 14c, and 14d have the same capacitance. If the capacitance of each of the capacitors 14a, 14b, 14c, and 14d is C, C can be expressed by Equation 35. In Equation 34, Z0 is the characteristic impedance of the power transmitting electrode pair 13c, and φ is the phase lag amount (i.e., the phase lag amount) caused by the power transmitting electrode pair 13c.

[0071]

number

number

[0072] Next, the operation of the power transmitting electrodes 10a, 10b of this embodiment will be described with reference to Fig. 17 to Fig. 23. Fig. 17 is a schematic diagram illustrating the impedance Z(d) of the power transmitting electrodes 10a, 10b in a comparative example that does not include the voltage compensation circuit 14. Fig. 18 is a diagram illustrating the impedance at positions p1, p2, p3, and p4 of the power transmitting electrodes 10a, 10b in a comparative example.

[0073] As shown in Fig. 17, impedance Z(d) is the impedance on the side of the terminations 12a and 12b of the power transmitting electrodes 10a and 10b at a position a distance d away from the terminations 12a and 12b. Here, the terminations 12a and 12b of the power transmitting electrodes 10a and 10b are open. In this case, impedance Z(d) is expressed by the following equation (36). β in equation (35) is a phase constant and is expressed by the following equation (37).

number

number

[0074] Position p1 in FIG. 18 is a position of the power transmitting electrodes 10a, 10b that is Mq away from the ends 12a, 12b. As described above, Mq is the value obtained by dividing λ by 4. Position p2 is a position of the power transmitting electrodes 10a, 10b that is closer to the ends 12a, 12b with respect to position p1. Position p3 is a position of the power transmitting electrodes 10a, 10b that is closer to the ends 12a, 12b with respect to position p2. Position p4 is a position of the power transmitting electrodes 10a, 10b that is closer to the ends 12a, 12b with respect to position p3. Position p4 is a position of the power transmitting electrodes 10a, 10b that is closer to the ends 12a, 12b with respect to position p3. Position p4 is a position of the power transmitting electrodes 10a, 10b that is closer to the ends 12a, 12b. Positions p1, P2, and P3 are positions that become more distant from the ends 12a, 12b of the power transmitting electrodes 10a, 10b in the order of position p4, p3, P2, and P1.

[0075] The impedance Z(d) at position p1 of the power transmitting electrodes 10a, 10b is defined as impedance Zp1. The impedance Z(d) at position p2 of the power transmitting electrodes 10a, 10b is defined as impedance Zp2. The impedance Z(d) at position p3 of the power transmitting electrodes 10a, 10b is defined as impedance Zp3. The impedance Z(d) at position p4 of the power transmitting electrodes 10a, 10b is defined as impedance Zp4. The impedance Zp4 at position p4 is infinite, and an antinode of the voltage standing wave occurs at position p4.

[0076] The symbol Zp1 in the Smith chart of FIG. 19(a) indicates the impedance at position p1. The symbol Zp2 in the Smith chart of FIG. 19(b) indicates the impedance at position p2. The symbol Zp3 in the Smith chart of FIG. 19(c) indicates the impedance at position p3. The symbol Zp4 in the Smith chart of FIG. 19(d) indicates the impedance at position p4. As shown in FIGS. 19(a), 19(b), 19(c), and 19(d), the phase lags as one moves from the terminal ends 12a and 12b (i.e., position p4) of the power transmitting electrodes 10a and 10b toward the starting ends 11a and 11b.

[0077] Therefore, the voltage value of the voltage standing wave gradually decreases from position p4 to positions p3, p2, and p1 in that order. At position p1, the impedance Zp1 becomes zero, and therefore a node of the voltage standing wave occurs at position p1. For this reason, when the power receiving electrodes 20a, 20b face the position p1 of the power transmitting electrodes 10a, 10b, it becomes difficult to supply power from the AC power supply 4 to the mobile object 3. Therefore, in this embodiment, in order to prevent the occurrence of a node of the voltage standing wave, the above-described voltage compensation circuit 14 is provided between two adjacent power transmitting electrode pairs 13c among the multiple power transmitting electrode pairs 13c.

[0078] Fig. 20 shows the configuration of a single power transmitting electrode pair 13c. As shown in Fig. 20, the length Mc of each of the multiple power transmitting electrode pairs 13c in the movement direction Ya is set to be less than Mq. In each of the multiple power transmitting electrode pairs 13c, the end on the AC power supply 4 side is defined as a starting end 13f, and in each of the multiple power transmitting electrode pairs 13c, the end opposite to the starting end 13f is defined as a terminal end 13e. In each of the multiple power transmitting electrode pairs 13c, the impedance on the terminal end 13e side at a position a distance d away from the terminal end 13e is defined as impedance Z(d).

[0079] FIG. 21 is a diagram showing the circuit configuration of the power transmitting electrodes 10a and 10b in this embodiment. The symbol Zm1 in the Smith chart of FIG. 22(a) indicates the impedance Z(d) at position m1 in FIG. 21. The symbol Zm2 in the Smith chart of FIG. 22(b) indicates the impedance Z(d) at position m2 in FIG. 21. The symbol Zm3 in the Smith chart of FIG. 22(c) indicates the impedance Z(d) at position m3 in FIG. 21. The symbol Zm4 in the Smith chart of FIG. 22(d) indicates the impedance Z(d) at position m4 in FIG. 21. The symbol Zm5 in the Smith chart of FIG. 22(e) indicates the impedance Z(d) at position m5 in FIG. 21.

[0080] 21, for convenience of explanation, voltage compensation circuits 14A and 14B are used to distinguish between the two voltage compensation circuits 14, and power transmitting electrode pairs 13c1 and 13c2 are used to distinguish between the two power transmitting electrode pairs 13c. Note that in FIG. 21, the reference symbols Zm1, Zm2, Zm3, Zm4, and Zm5 are not shown to clearly illustrate the reference symbols Zm1, Zm2, Zm3, Zm4, and Zm5, and the reference symbols of the capacitors 14a, 14b, 14c, and 14d and the inductor 14e that configure the voltage compensation circuits 14A and 14B are not shown.

[0081] As shown in FIG. 21 , position m1 is a position of the power transmitting electrodes 10a, 10b that is closer to the AC power supply 4 than the voltage compensation circuit 14A. Position m2 is a position of the power transmitting electrodes 10a, 10b that is between the voltage compensation circuit 14A and the power transmitting electrode pair 13c1. Position m3 is a position of the power transmitting electrodes 10a, 10b that is between the power transmitting electrode pair 13c1 and the voltage compensation circuit 14B. Position m4 is a position of the power transmitting electrodes 10a, 10b that is between the voltage compensation circuit 14B and the power transmitting electrode pair 13c2. Position m5 is a position of the ends 12a, 12b of the power transmitting electrodes 10a, 10b.

[0082] The impedance Z(d) of the power transmitting electrodes 10a, 10b on the side of the terminals 12a, 12b with respect to position m1 is defined as impedance Zm1. The impedance Z(d) of the power transmitting electrodes 10a, 10b on the side of the terminals 12a, 12b with respect to position m2 is defined as impedance Zm2. The impedance Z(d) of the power transmitting electrodes 10a, 10b on the side of the terminals 12a, 12b with respect to position m3 is defined as impedance Zm3. The impedance Z(d) of the power transmitting electrodes 10a, 10b on the side of the terminals 12a, 12b with respect to position m4 is defined as impedance Zm4. The impedance Z(d) of the power transmitting electrodes 10a, 10b at position m5 (i.e., the terminals 12a, 12b) is defined as impedance Zm5.

[0083] In the power transmitting electrode pair 13c2, as shown in FIGS. 22(e) and 22(d), the phase lags more as it moves from the terminal end 13e toward the starting end 13f. The voltage compensation circuit 14B advances the phase as shown in FIG. 22(c). In this way, the voltage compensation circuit 14B compensates for the phase lag caused by the power transmitting electrode pair 13c2. In the power transmitting electrode pair 13c1, as shown in FIG. 22(b), the phase lags more as it moves from the terminal end 13e toward the starting end 13f. The voltage compensation circuit 14A advances the phase as shown in FIG. 22(a). In this way, the voltage compensation circuit 14A compensates for the phase lag caused by the power transmitting electrode pair 13c1. That is, the voltage compensation circuit 14 compensates for the phase lag caused by the power transmitting electrode pair 13 on the terminal end 12a, 12b side of the two power transmitting electrode pairs 13. This allows the impedance Z(d) of the power transmitting electrodes 10a and 10b to be maintained at a high level over a wide range in the movement direction Ya.

[0084] According to the present embodiment described above, the wireless power feeding system 1 includes the power transmitting electrodes 10a and 10b, and a plurality of voltage compensation circuits 14. The power transmitting electrode 10a includes a plurality of divided electrode portions 13a arranged in the movement direction Ya. The power transmitting electrode 10b includes a plurality of divided electrode portions 13b arranged in the movement direction Yb. Furthermore, each of the divided electrode portions 13a, together with a corresponding divided electrode portion 13b among the plurality of divided electrode portions 13b, constitutes a plurality of power transmitting electrode pairs 13c arranged in the movement direction Ya.

[0085] The length Mc of each of the power transmitting electrode pairs 13c in the movement direction Ya is less than the division value Mq obtained by dividing λ by 4. λ is the wavelength of the AC voltage output from the AC power supply 4. A voltage compensation circuit 14 is provided between two adjacent power transmitting electrode pairs 13c among the power transmitting electrode pairs 13c. The voltage compensation circuit 14 compensates for a phase delay that occurs in one of the two power transmitting electrode pairs 13c (specifically, the power transmitting electrode pair 13c on the terminal end 12a, 12b side) as the power transmitting electrode pair 13c moves from the terminal end 13e to the starting end 13f. As a result, each of the voltage compensation circuits 14 suppresses a drop in voltage between the power transmitting electrodes 10a, 10b. Therefore, as shown in the graph Vh of FIG. 23, the voltage generated in the power transmitting electrodes 10a, 10b can be maintained high throughout the entire power transmitting electrodes 10a, 10b.

[0086] Therefore, power can be supplied to the power receiving electrodes 20a, 20b of the moving object 3 over a wide range of the power transmitting electrodes 10a, 10b in the movement direction Ya. In Fig. 23, the vertical axis represents the voltage generated between the power transmitting electrodes 10a, 10b, and the horizontal axis represents the position of the power transmitting electrodes 10a, 10b in the movement direction Ya. Graph Vh in Fig. 23 represents the voltage between the power transmitting electrodes 10a, 10b in this embodiment, and graph Vr in Fig. 23 represents the voltage between the power transmitting electrodes 10a, 10b when multiple voltage compensation circuits 14 are not provided.

[0087] (Fourth embodiment) In the third embodiment, an example was described in which a voltage compensation circuit 14 was provided in which an inductor 14e was connected between the common connection terminal of capacitors 14a and 14b and the common connection terminal of capacitors 14c and 14d. Instead, a fourth embodiment will be described in which an inductor 14f is connected between the common connection terminal of capacitors 14a and 14b and ground, and an inductor 14g is connected between the common connection terminal of capacitors 14c and 14d and ground.

[0088] Fig. 24 shows the details of a portion of the power transmitting electrodes 10a, 10b of this embodiment. The power transmitting electrodes 10a, 10b of this embodiment differ from the power transmitting electrodes 10a, 10b of the third embodiment in the circuit configuration of the voltage compensation circuit 14. In Fig. 24, the same reference numerals as in Fig. 16 indicate the same components, and their explanations will be omitted. Furthermore, the voltage compensation circuit 14 of this embodiment is provided with inductors 14f, 14g instead of the inductor 14e in the voltage compensation circuit 14 of the third embodiment.

[0089] In this embodiment configured as described above, the multiple voltage compensation circuits 14 are each disposed between the two power transmitting electrode pairs 13c, similar to the voltage compensation circuits 14 in the third embodiment. Each of the multiple voltage compensation circuits 14 compensates for a phase delay caused by one of the two power transmitting electrode pairs 13c, thereby suppressing a voltage drop between one of the power transmitting electrode pairs 13c. This makes it possible to maintain a high voltage across the power transmitting electrodes 10a, 10b. This allows power to be supplied to the power receiving electrodes 20a, 20b of the moving object 3 over a wide range of the power transmitting electrodes 10a, 10b in the movement direction Ya.

[0090] (Fifth embodiment) In the third embodiment, an example was described in which a voltage compensation circuit 14 in which an inductor 14e is connected between the common connection terminal of capacitors 14a and 14b and the common connection terminal of capacitors 14c and 14d is provided. Instead, a fifth embodiment using a pseudo-left-handed circuit in which inductor 14e is eliminated from the voltage compensation circuit 14 will be described with reference to FIG. 25 . FIG. 25 shows details of a portion of the power transmission electrodes 10a and 10b of this embodiment. The power transmission electrodes 10a and 10b of this embodiment differ from the power transmission electrodes 10a and 10b of the third embodiment in the circuit configuration of the voltage compensation circuit 14. In FIG. 25, the same reference numerals as those in FIG. 16 indicate the same components, and their description will be omitted.

[0091] In this embodiment, each of the plurality of voltage compensation circuits 14 is disposed between two adjacent divided electrode portions 13a among the plurality of divided electrode portions 13a. Each of the plurality of voltage compensation circuits 14 includes capacitors 14h and 14i. Capacitor 14h is connected between two adjacent divided electrode portions 13a among the plurality of divided electrode portions 13a. Capacitor 14i is connected between two adjacent divided electrode portions 13b among the plurality of divided electrode portions 13b. In this way, each of the plurality of voltage compensation circuits 14 does not include an inductor, but is a pseudo left-handed circuit that includes capacitors 14h and 14i.

[0092] Furthermore, in the third embodiment, if the inductance value of the inductor 14e of the voltage compensation circuit 14 is large, the inductor 14e becomes an element that prevents AC current from flowing in the AC circuit. In this case, the voltage compensation circuit 14 of FIG. 16 becomes substantially similar to a voltage compensation circuit obtained by deleting the inductor 14e from the voltage compensation circuit 14. Similarly, in the fourth embodiment, if the inductance values ​​of the inductors 14f and 14g of the voltage compensation circuit 14 are large, the inductors 14f and 14g become elements that prevent AC current from flowing in the AC circuit. Therefore, the voltage compensation circuit 14 of FIG. 24 becomes substantially similar to a voltage compensation circuit obtained by deleting the inductors 14f and 14g from the voltage compensation circuit 14.

[0093] For example, when the parasitic capacitance between the power transmitting electrodes 10a and 10b is small, the inductance of the inductor 14e or the inductors 14f and 14g becomes large. In this case, the inductor 14e can be eliminated from the voltage compensation circuit 14 shown in FIG. 16. Alternatively, the inductors 14f and 14g can be eliminated from the voltage compensation circuit 14 shown in FIG. 24. Therefore, the voltage compensation circuits 14 of the third and fourth embodiments have substantially the same circuit configuration as the voltage compensation circuit 14 of the present embodiment shown in FIG. 25, which is a pseudo-left-handed circuit.

[0094] (Sixth embodiment) In the first embodiment, an example in which power is supplied to one moving object 3 in the wireless power supply system 1 has been described. However, instead of this, a sixth embodiment in which power is supplied to multiple moving objects 3 in the wireless power supply system 1 will be described with reference to Figs. 26 to 29. Fig. 26 is a schematic diagram showing a state in which power is supplied from the power transmitting electrodes 10a, 10b to multiple moving objects 3 while they are traveling in a predetermined area 2 in the wireless power supply system 1 of this embodiment. Fig. 26 shows a specific example in which two moving objects 3 are traveling in the predetermined area 2.

[0095] Fig. 27 is a circuit diagram showing the overall circuit configuration of the wireless power feeding system 1 in this embodiment when multiple moving objects 3 are being supplied with power from the power feeding electrodes 10a, 10b while moving relative to the power feeding electrodes 10a, 10b in a predetermined area 2. In Fig. 27, the same reference numerals as in Fig. 3 indicate the same components, and their description will be omitted. The wireless power feeding system 1 of this embodiment includes multiple matching circuits 30, matching circuits 40, a coupler 60, and multiple electrical loads 50.

[0096] The plurality of matching circuits 30 are arranged in parallel between power supply electrodes 4a, 4b of the AC power supply 4. Each of the plurality of matching circuits 30 is mounted on a corresponding one of the plurality of moving bodies 3. Each of the plurality of matching circuits 30 is arranged between the coupler 60 and an electrical load 50 for each of the moving bodies 3. Each of the plurality of matching circuits 30 includes inductors 31, 32. The matching circuit 40 is arranged between the AC power supply 4 and the coupler 60. Each of the plurality of electrical loads 50 is mounted on a corresponding one of the plurality of moving bodies 3.

[0097] 27 , the coupler 60 includes a plurality of capacitors 63, a plurality of capacitors 64, a plurality of parasitic capacitances 65, a plurality of parasitic capacitances 66, parasitic inductances 61 and 62, a plurality of parasitic inductances 68, and a plurality of parasitic inductances 69. Each of the plurality of capacitors 63 is formed by the power receiving electrode 20a and the power transmitting electrode 10a of a corresponding one of the plurality of moving bodies 3. Each of the plurality of capacitors 63 uses the air between the power transmitting electrode 10a and the power receiving electrode 20a of each moving body 3 as a dielectric.

[0098] Each of the plurality of capacitors 64 is formed by the power receiving electrode 20b and the power transmitting electrode 10b of a corresponding one of the plurality of mobile bodies 3. The plurality of capacitors 64 each use the air between the power transmitting electrode 10b and the power receiving electrode 20b of each of the mobile bodies 3 as a dielectric. In this embodiment, the capacitors 63, 64 and the parasitic capacitances 65, 66 form a coupling circuit 90. A coupling circuit 90 is provided for each mobile body 3. The parasitic inductance 61 is an inductance formed in a current path through which an AC current flows between the AC power source 4 and the power receiving electrode 20a of the power transmitting electrode 10a. The parasitic inductance 61 is formed between the matching circuit 40 and the mobile body 3 that is closest to the AC power source 4 among the plurality of mobile bodies 3.

[0099] The parasitic inductance 62 is an inductance formed in a current path of the power transmitting electrode 10b through which an AC current flows between the AC power source 4 and the power receiving electrode 20b. The parasitic inductance 62 is formed between the matching circuit 40 and the mobile object 3 that is closest to the AC power source 4 among the multiple mobile objects 3. The parasitic capacitance 65 is an electrostatic capacitance formed between the power transmitting electrodes 10a, 10b for each mobile object 3. The parasitic capacitance 66 is an electrostatic capacitance formed between the power receiving electrodes 20a, 20b for each mobile object 3.

[0100] Here, each of the multiple parasitic inductances 68 is an inductance formed in the power transmitting electrode 10a on a current path through which an AC current flows from the AC power supply 4. Each of the multiple parasitic inductances 68 is disposed between two adjacent capacitors 63 among the multiple capacitors 63. Each of the multiple parasitic inductances 69 is an inductance formed in the power transmitting electrode 10b on a current path through which an AC current flows from the AC power supply 4.

[0101] Each of the plurality of parasitic inductances 69 is disposed between two adjacent capacitors 64 among the plurality of capacitors 64. In the wireless power feeding system 1 of the present embodiment configured as described above, if the plurality of parasitic inductances 68 and the plurality of parasitic inductances 69 are deleted for reasons described below, the wireless power feeding system 1 approximately forms an equivalent circuit shown in Fig. 28. In the present embodiment, as in the above-described embodiments, the power transmitting electrode length Ma of the power transmitting electrodes 10a, 10b is set to be equal to or less than Mq. The power transmitting electrode length Ma of the power transmitting electrodes 10a, 10b is longer than the power receiving electrode length Mb of the power receiving electrodes 20a, 20b.

[0102] Hereinafter, for ease of explanation, in order to distinguish between the multiple matching circuits 30 in Fig. 28, the multiple matching circuits 30 will also be referred to as matching circuits 301, 302, ... 30M. Furthermore, in order to distinguish between the multiple electrical loads 50, the multiple electrical loads 50 will also be referred to as electrical loads 501, 502, ... 50M. Matching circuit 301 corresponds to electrical load 501, matching circuit 302 corresponds to electrical load 502, and matching circuit 30M corresponds to electrical load 50M. M is an integer of 2 or greater.

[0103] In this embodiment, the impedance on the coupler 60 side with respect to the observation line 70c1 in the wireless power feeding system 1 with the common connection terminals 73a and 73b open is defined as impedance Zl1. That is, the impedance Zl1 is the impedance on the coupler 60 side with respect to the matching circuit 301 with the common connection terminals 73a and 73b open. The observation line 70c1 is a virtual line connecting the common connection terminals 70a1 and 70b1 to which the coupler 60 and the matching circuit 301 are commonly connected.

[0104] The matching circuit 301 has an impedance that cancels the reactance of the impedance Zl1. The observation line 72c1 is an imaginary line connecting the common connection terminals 72a1 and 72b1 to which the electrical load 501 and the matching circuit 301 are commonly connected. The impedance on the matching circuit 301 side of the observation line 72c1 in the wireless power feeding system 1 is defined as impedance Zr1. The impedance Zr1 has a resistance value other than the reactance of the impedance Zl1.

[0105] With the common connection terminals 73a and 73b open, the impedance on the coupler 60 side with respect to the observation line 70c2 in the wireless power feeding system 1 is set to impedance Zl2. That is, the impedance Zl2 is the impedance on the coupler 60 side with respect to the matching circuit 302 with the common connection terminals 73a and 73b open. The observation line 70c2 is an imaginary line connecting the common connection terminals 70a2 and 70b2 to which the coupler 60 and the matching circuit 302 are commonly connected.

[0106] The matching circuit 302 has an impedance that cancels the reactance of the impedance Zl2. The observation line 72c2 is an imaginary line connecting the common connection terminals 72a2 and 72b2 to which the electrical load 502 and the matching circuit 302 are commonly connected. The impedance on the matching circuit 302 side of the observation line 72c2 in the wireless power feeding system 1 is defined as impedance Zr2. The impedance Zr2 has a resistance value other than the reactance of the impedance Zl2.

[0107] With the common connection terminals 73a and 73b open, the impedance on the coupler 60 side with respect to the observation line 70cM in the wireless power feeding system 1 is defined as impedance ZlM. That is, the impedance ZlM is the impedance on the coupler 60 side with respect to the matching circuit 30M with the common connection terminals 73a and 73b open. The observation line 70cM is a virtual line connecting the common connection terminals 70aM and 70bM to which the coupler 60 and the matching circuit 30M are commonly connected.

[0108] The matching circuit 30M has an impedance that cancels the reactance of the impedance ZlM. The observation line 72cM is an imaginary line connecting the common connection terminals 72aM and 72bM to which the electrical load 50M and the matching circuit 30M are commonly connected. The impedance on the matching circuit 30M side with respect to the observation line 72cM in the wireless power feeding system 1 is defined as impedance ZrM. The impedance ZrM has a resistance value other than the reactance of the impedance ZlM. In this way, each of the multiple matching circuits 30 has an impedance that cancels the reactance of the impedance on the coupler 60 side.

[0109] In this embodiment, each of the multiple matching circuits 30 constitutes a connecting body 80, which is a four-terminal circuit connected to a corresponding one of the multiple coupling circuits 90 in the coupler 60. As a result, in the wireless power supply system 1, a connecting body 80 is provided for each moving object 3. An F matrix representing the relationship between the input voltage, input current, output voltage, and output current of each of the multiple connecting bodies 80 is defined as [Fdk], where k is any value of an integer from 1 to m, and m is an integer of 2 or more.

[0110] Hereinafter, for ease of explanation, the multiple connections 80 will be referred to as connections 801, 802, ... 80M in order to distinguish the multiple connections 80 for each moving object 3. The F matrix of connection 801 is [Fd1], the F matrix of connection 802 is [Fd2], and the F matrix of connection 80M is [Fdm]. Furthermore, for ease of explanation, the resistance values ​​R of the multiple electrical loads 50 will be referred to as resistance values ​​R1, R2, ... RM in order to distinguish the resistance values ​​R of the multiple electrical loads 50 for each moving object 3. Here, the connection relationship between the AC power supply 4, the matching circuit 40, the multiple connections 80, and the multiple electrical loads 50 has the circuit configuration shown in FIG.

[0111] Each of the multiple connections 80 is a linear circuit. Therefore, the circuit configuration in Fig. 29 is a superposition of the matching circuit 40 and the multiple connections 80. Furthermore, [Fs][Fdk], which is the product of [Fdk], the F matrix of the multiple connections 80, and [Fs], the F matrix of the matching circuit 40, can be expressed by equation 38. [Fdk] can be expressed by F parameters such as Ad, jBd, jCd, and Dd.

[0112]

number

number

[0113] The points where the matching circuit 40 and the AC power supply 4 are commonly connected are defined as common connection terminals 71a and 71b, and the line connecting the common connection terminals 71a and 71b is defined as observation line 71c. Furthermore, the impedance of the wireless power supply system 1 on the coupler 60 side with respect to observation line 71c is defined as impedance Zin. In this embodiment, the matching circuit 40 and the multiple connecting bodies 80 function as a transformer with a transformation ratio N. In this case, impedance Zin is N, which is the square of N, as shown in equation 40. 2 and the combined resistance value RG.

[0114]

number

[0115] The reason for eliminating the multiple parasitic inductances 68 and the multiple parasitic inductances 69 from the equivalent circuit of the wireless power supply system 1 will be described below. That is, in the first embodiment, the power transmission electrode length Ma of the power transmission electrodes 10a, 10b is set to be equal to or less than Mq. Mq is a value obtained by dividing λ, which is the wavelength of the voltage of the AC power supply 4, by 4. In this case, when the multiple moving objects 3 move, the distance between two adjacent moving objects 3 of the power transmission electrodes 10a, 10b is small. Therefore, the voltage drop between the two adjacent moving objects 3 between the power transmission electrodes 10a, 10b is small. In this case, it is considered that the influence of the multiple parasitic inductances 68 and the multiple parasitic inductances 69 is small. Therefore, it is possible to eliminate the multiple parasitic inductances 68 and the multiple parasitic inductances 69 from the equivalent circuit of the wireless power supply system 1.

[0116] In the second embodiment, the power transmitting electrode length Ma of the power transmitting electrodes 10a, 10b is set to be equal to or shorter than Mh. Mh is the value obtained by dividing λ, which is the wavelength of the voltage of the AC power supply 4, by 2. In this case, a capacitor 10c is added to the ends 12a, 12b of the power transmitting electrodes 10a, 10b. In this case, the antinodes of the voltage standing wave generated between the power transmitting electrodes 10a, 10b are located at the central portions 15a, 15b of the power transmitting electrodes 10a, 10b in the movement direction Ya.

[0117] Therefore, within the range of the power transmitting electrodes 10a, 10b used by the multiple moving bodies 3 for power feeding, the voltage drop between two adjacent moving bodies 3 among the multiple moving bodies 3 is small. That is, it is considered that the influence of the multiple parasitic inductances 68 and the multiple parasitic inductances 69 is small. Therefore, in the equivalent circuit of the wireless power feeding system 1, the multiple parasitic inductances 68 and the multiple parasitic inductances 69 can be eliminated.

[0118] In the third embodiment, voltage compensation circuit 14 constituting a left-handed circuit is provided between two adjacent pairs of power transmission electrodes 13c among the plurality of pairs of power transmission electrodes 13c. Capacitors 14a, 14b, 14c, and 14d constituting voltage compensation circuit 14 satisfy the condition for resonance together with parasitic inductances 61 and 62, multiple parasitic inductances 68, and multiple parasitic inductances 69. Therefore, capacitors 14a, 14b, 14c, and 14d cancel out parasitic inductances 61 and 62, multiple parasitic inductances 68, and multiple parasitic inductances 69.

[0119] Therefore, it is possible to eliminate the multiple parasitic inductances 68 and the multiple parasitic inductances 69 in the equivalent circuit of the wireless power feeding system 1. Similarly, in the case of the above-described fourth embodiment, the capacitors 14a, 14b, 14c, and 14d cancel the parasitic inductances 61 and 62, the multiple parasitic inductances 68, and the multiple parasitic inductances 69. Therefore, it is possible to eliminate the multiple parasitic inductances 68 and the multiple parasitic inductances 69 in the equivalent circuit of the wireless power feeding system 1.

[0120] Similarly, in the case of the fifth embodiment using voltage compensation circuit 14 formed of a pseudo left-handed circuit, capacitors 14h and 14i cancel parasitic inductances 61 and 62, multiple parasitic inductances 68, and multiple parasitic inductances 69. Therefore, in the equivalent circuit of wireless power feeding system 1, multiple parasitic inductances 68 and multiple parasitic inductances 69 can be eliminated. According to the present embodiment described above, the wireless power supply system 1 contactlessly supplies AC power output from the AC power source 4 to the electric loads 50 mounted on each of the plurality of moving bodies 3 while the plurality of moving bodies 3 are moving in a predetermined area 2.

[0121] The wireless power feeding system 1 is arranged in a predetermined area 2 and includes power transmitting electrodes 10a and 10b that transmit AC power output from an AC power source 4. The wireless power feeding system 1 is mounted on each of a plurality of moving objects 3 and includes power receiving electrodes 20a and 20b that are electric field coupled to the pair of power transmitting electrodes 10a and 10b and, together with the pair of power transmitting electrodes 10a and 10b, form a coupler 60. The power receiving electrodes 20a and 20b receive the AC power output from the power transmitting electrodes 10a and 10b for each moving object 3.

[0122] Furthermore, the wireless power supply system 1 includes a matching circuit 30 arranged between the coupler 60 and the electrical load 50 of each moving object 3, and a matching circuit 40 arranged between the AC power source 4 and the coupler 60. Two terminals to which the coupler 60 and the matching circuit 40 are commonly connected are defined as two common connection terminals 73a and 73b. When the common connection terminals 73a and 73b are open, the impedance on the coupler 60 side with respect to the matching circuit 40 of each moving object 3 is defined as impedance Zl1, Zl2, ... ZlM of each moving object 3.

[0123] Furthermore, in this embodiment, the matching circuit 30 has an impedance that cancels reactance among the impedances Zl1, Zl2, ... ZlM for each moving body 3. A combined resistance value RG is a value obtained by combining the resistance values ​​R1, R2, ... RM of the electrical loads 50 of the multiple moving bodies 3. The matching circuit 40 operates so that the impedance Zin on the matching circuit 40 side with respect to the AC power source 4 is proportional to the combined resistance value RG.

[0124] Therefore, the reactance of the impedances Zl1, Zl2, ... ZlM is canceled for each moving object 3. As a result, the impedance Zin changes in proportion to the combined resistance value RG of the multiple electric loads 50. As a result, the current flowing from the AC power supply 4 to the multiple electric loads 50 is changed in accordance with the change in the combined resistance value RG, thereby supplying power from the AC power supply 4 to the multiple electric loads 50. Therefore, it is possible to provide a wireless power feeding system 1 that can effectively supply AC power output from the AC power supply 4 to the multiple electric loads 50.

[0125] (Other embodiments)

[0126] (1) In the above first to sixth embodiments, an example has been described in which a robot that moves on a floor in a factory is used as the mobile object 3. Alternatively, a vehicle that travels in a predetermined area 2 of a road may be used as the mobile object 3. In this case, the power transmitting electrodes 10a and 10b are arranged in the predetermined area 2 of the road. The power receiving electrodes 20a and 20b, the matching circuits 30 and 40, and the electrical load 50 are arranged on the vehicle. Note that the mobile object 3 may be various mobile objects other than a vehicle.

[0127] (2) In the first to sixth embodiments, the power transmitting electrodes 10a, 10b are formed to extend straight. However, instead of this, the power transmitting electrodes 10a, 10b may be curved. For example, the power transmitting electrodes 10a, 10b may each be formed in a Y-shape. The power transmitting electrodes 10a, 10b may each be formed in a loop shape.

[0128] (3) The wireless power feeding system 1 of the sixth embodiment may be implemented by combining the power transmitting electrodes 10a and 10b of the second embodiment. That is, the power transmitting electrode length Ma of the power transmitting electrodes 10a and 10b is longer than the power receiving electrode length Mb of the power receiving electrodes 20a and 20b. The power transmitting electrode length Ma of the power transmitting electrodes 10a and 10b is set to be equal to or less than the divided value Mh. A capacitor 10c with high capacitance is connected between the terminal ends 12a and 12b of the power transmitting electrodes 10a and 10b. The terminal ends 12a and 12b of the power transmitting electrodes 10a and 10b become nodes of a voltage standing wave. Accordingly, the center portions of the power transmitting electrodes 10a and 10b in the movement direction Ya become antinodes of the voltage standing wave. Therefore, when the power receiving electrodes 20a, 20b of the moving object 3 face the central portions of the power transmitting electrodes 10a, 10b, power can be effectively supplied from the power transmitting electrodes 10a, 10b to the power receiving electrodes 20a, 20b.

[0129] (4) The wireless power feeding system 1 of the sixth embodiment may be implemented by combining the power transmitting electrodes 10a and 10b of the third embodiment. That is, the power transmitting electrode 10a includes a plurality of divided electrode portions 13a. The power transmitting electrode 10b includes a plurality of divided electrode portions 13b. Each of the divided electrode portions 13a, together with a corresponding divided electrode portion 13b among the plurality of divided electrode portions 13b, constitutes a plurality of power transmitting electrode pairs 13c aligned in a line in the movement direction Ya. A voltage compensation circuit 14 that compensates for a phase delay is provided between two adjacent power transmitting electrode pairs 13c among the plurality of power transmitting electrode pairs 13c. The phase refers to the phase of the AC current relative to the AC voltage.

[0130] The voltage compensation circuit 14 compensates for the phase delay that occurs in one of the two power transmitting electrode pairs 13c as it moves from the end point 13e to the start point 13f, thereby suppressing a drop in voltage between the power transmitting electrodes 10a and 10b. (5) The wireless power supply system 1 of the sixth embodiment may be implemented using the voltage compensation circuit 14 of the fourth embodiment. The wireless power supply system 1 of the sixth embodiment may be implemented using the voltage compensation circuit 14 of the fifth embodiment.

[0131] (6) In the wireless power feeding system 1 of the third embodiment, the voltage compensation circuit 14 is disposed between two adjacent power feeding electrode pairs 13c. The voltage compensation circuit 14 compensates for a phase delay occurring in the power feeding electrode pair 13c on the ends 12a and 12b side of the two power feeding electrode pairs 13c as the power feeding electrode pair 13c approaches from the end 13e to the start 13f. However, instead of this, the voltage compensation circuit 14 may compensate for a phase delay occurring in the power feeding electrode pair 13c on the start 11a and 11b side of the two power feeding electrode pairs 13c as the power feeding electrode pair 13c approaches from the end 13e to the start 13f. The wireless power feeding systems 1 of the fourth and fifth embodiments may also include a voltage compensation circuit 14. (7) In the wireless power supply system 1 of the third embodiment, the frequency of the AC voltage output from the AC power supply 4 is set to a frequency of several MHz. However, the present invention is not limited to this, and the frequency of the AC voltage output from the AC power supply 4 may be set to a frequency of several GHz.

[0132] (8) The present disclosure is not limited to the above-described embodiments and can be modified as appropriate within the scope of the claims. Furthermore, the above-described embodiments are not unrelated to each other and can be combined as appropriate unless the combination is clearly impossible. It goes without saying that, in each of the above embodiments, the elements constituting the embodiments are not necessarily essential unless specifically stated as essential or clearly considered essential in principle. Furthermore, in each of the above embodiments, when numerical values ​​such as the number, values, amounts, and ranges of components of the embodiments are mentioned, they are not limited to the specific numbers unless specifically stated as essential or clearly limited to a specific number in principle. Furthermore, in each of the above embodiments, when the shape, positional relationship, etc. of components, etc. are mentioned, they are not limited to the shape, positional relationship, etc., unless specifically stated or clearly limited to a specific shape, positional relationship, etc. in principle. [Explanation of symbols]

[0133] 1. Wireless power supply system 2 Predetermined area 3. Mobile 4 AC power supply 10a Power transmission electrode 10b Power transmission electrode 20a Receiving electrode 20b Power receiving electrode 30 matching circuit 40 matching circuit 73a Common connection terminal 73b Common connection terminal

Claims

1. A wireless power supply system that supplies AC power output from an AC power source (4) to an electrical load (50) mounted on a moving object (3) in a wireless manner when the moving object (3) moves within a predetermined area (2), a pair of power transmission electrodes (10a, 10b) disposed in the predetermined area and configured to transmit AC power output from the AC power supply; a pair of power receiving electrodes (20a, 20b) mounted on the moving body, configured to be electric field coupled to the pair of power transmitting electrodes to form a coupler (60) together with the pair of power transmitting electrodes, and receiving AC power output from the pair of power transmitting electrodes; a first matching circuit (30) disposed between the coupler and the electrical load; a second matching circuit (40) disposed between the AC power source and the coupler; When the two terminals to which the coupler and the second matching circuit are commonly connected are defined as two common connection terminals (73a, 73b), and the impedance on the coupler side with respect to the first matching circuit is defined as a first impedance (Zl) in a state in which the two common connection terminals are open, the first matching circuit has an impedance that cancels a reactance of the first impedance, The second matching circuit operates to make a second impedance (Zin) on the second matching circuit side relative to the AC power source proportional to a resistance value (R) of the electrical load.

2. In the case where the length of each of the pair of power transmitting electrodes in the movement direction of the moving body is defined as a power transmitting electrode length (Ma), and the length of each of the pair of power receiving electrodes in the movement direction of the moving body is defined as a power receiving electrode length (Mb), the power transmitting electrode length is longer than the power receiving electrode length, The wireless power supply system according to claim 1 , wherein the length of the power transmitting electrode is equal to or less than a value (Mq) obtained by dividing a wavelength (λ) of an output voltage of the AC power supply by four.

3. In the case where the length of each of the pair of power transmitting electrodes in the movement direction of the moving body is defined as a power transmitting electrode length (Ma), and the length of each of the pair of power receiving electrodes in the movement direction of the moving body is defined as a power receiving electrode length (Mb), the power transmitting electrode length is longer than the power receiving electrode length, the length of the power transmitting electrode is equal to or less than a value (Mh) obtained by dividing the wavelength (λ) of the AC voltage output from the AC power supply by 2, When ends of the pair of power transmission electrodes on the opposite side to the AC power supply are defined as terminations (12a, 12b), a capacitor (10c) is connected between the terminations of each of the pair of power transmission electrodes, 2. The wireless power supply system according to claim 1, wherein when a voltage standing wave occurs in the pair of power transmitting electrodes based on the AC voltage output from the AC power supply, the capacitor operates so that a node of the voltage standing wave occurs at the terminal ends of the pair of power transmitting electrodes.

4. The pair of power transmitting electrodes are a first power transmission electrode (10a) including a plurality of first divided electrode portions (13a) arranged in the moving direction of the moving body; a second power transmission electrode (10b) including a plurality of second divided electrode portions (13b) arranged in the moving direction of the moving body, The plurality of first divided electrode portions, together with corresponding second divided electrode portions among the plurality of second divided electrode portions, constitute a plurality of power transmission electrode pairs (13c) arranged in the movement direction, a length of each of the plurality of power transmitting electrode pairs in the moving direction of the moving body is equal to or less than a value (Mq) obtained by dividing a wavelength (λ) of an AC voltage output from the AC power supply by 4, A voltage compensation circuit (14) is provided between two adjacent pairs of power transmission electrodes among the plurality of power transmission electrode pairs, and an end of each of the plurality of power transmission electrode pairs on the AC power supply side is defined as a starting end (13f), and an end of each of the plurality of power transmission electrode pairs on the opposite side to the AC power supply side is defined as a terminal end (13e), 2. The wireless power supply system according to claim 1, wherein the voltage compensation circuit suppresses a drop in voltage between the pair of power transmission electrodes by compensating for a phase delay that occurs in one of the two power transmission electrode pairs as the pair approaches from the end point to the start point.

5. A wireless power supply system that supplies AC power output from an AC power source (4) to an electric load (50) mounted on each of a plurality of moving bodies (3) in a wireless manner when the moving bodies (3) move in a predetermined area (2), a pair of power transmission electrodes (10a, 10b) disposed in the predetermined area and configured to transmit AC power output from the AC power supply; a pair of power receiving electrodes (20a, 20b) mounted on each of the plurality of moving bodies, configured to be coupled to the pair of power transmitting electrodes in an electric field to form a coupler (60) together with the pair of power transmitting electrodes, and receiving AC power output from the pair of power transmitting electrodes for each of the moving bodies; a first matching circuit (30) disposed between the coupler and the electrical load of each of the mobile units; a second matching circuit (40) disposed between the AC power source and the coupler; When the two terminals to which the coupler and the second matching circuit are commonly connected are defined as two common connection terminals (73a, 73b), and when the two common connection terminals are open, the impedance on the coupler side with respect to the first matching circuit for each of the moving bodies is defined as a first impedance (Zl1, Zl2, ... ZlM) for each of the moving bodies, the first matching circuit has an impedance for canceling a reactance of the first impedance for each of the moving objects, When a combined resistance value (RG) is a combined value of the resistance values ​​(R1, R2, ... RM) of the electrical loads of the plurality of moving bodies, the second matching circuit operates so that a second impedance (Zin) on the second matching circuit side with respect to the AC power supply is proportional to the combined resistance value.

6. In the case where the length of each of the pair of power transmitting electrodes in the movement direction of the moving body is defined as a power transmitting electrode length (Ma), and the length of each of the pair of power receiving electrodes in the movement direction of the moving body is defined as a power receiving electrode length (Mb), the power transmitting electrode length is longer than the power receiving electrode length, The wireless power supply system according to claim 5 , wherein the length of the power transmitting electrode is equal to or less than a value (Mq) obtained by dividing a wavelength (λ) of an output voltage of the AC power supply by four.

7. In the case where the length of each of the pair of power transmitting electrodes in the movement direction of the moving body is defined as a power transmitting electrode length (Ma), and the length of each of the pair of power receiving electrodes in the movement direction of the moving body is defined as a power receiving electrode length (Mb), the power transmitting electrode length is longer than the power receiving electrode length, the length of the power transmitting electrode is equal to or less than a value (Mh) obtained by dividing the wavelength (λ) of the AC voltage output from the AC power supply by 2, When ends of the pair of power transmission electrodes on the opposite side to the AC power supply are defined as terminations (12a, 12b), a capacitor (10c) is connected between the terminations of each of the pair of power transmission electrodes, 6. The wireless power supply system according to claim 5, wherein when a voltage standing wave occurs in the pair of power transmitting electrodes based on the AC voltage output from the AC power supply, the capacitor operates so that a node of the voltage standing wave occurs at the terminal ends of the pair of power transmitting electrodes.

8. The pair of power transmitting electrodes are a first power transmission electrode (10a) including a plurality of first divided electrode portions (13a) arranged in the moving direction of the moving body; a second power transmission electrode (10b) including a plurality of second divided electrode portions (13b) arranged in the moving direction of the moving body, The plurality of first divided electrode portions, together with corresponding second divided electrode portions among the plurality of second divided electrode portions, constitute a plurality of power transmission electrode pairs (13c) arranged in the movement direction, a length of each of the plurality of power transmitting electrode pairs in the moving direction of the moving body is equal to or less than a value (Mq) obtained by dividing a wavelength (λ) of an AC voltage output from the AC power supply by 4, A voltage compensation circuit (14) is provided between two adjacent pairs of power transmission electrodes among the plurality of power transmission electrode pairs, and an end of each of the plurality of power transmission electrode pairs on the AC power supply side is defined as a starting end (13f), and an end of each of the plurality of power transmission electrode pairs on the opposite side to the AC power supply side is defined as a terminal end (13e), 6. The wireless power supply system according to claim 5, wherein the voltage compensation circuit suppresses a drop in voltage between the pair of power transmission electrodes by compensating for a phase delay that occurs in one of the two power transmission electrode pairs as the pair of power transmission electrodes approaches from the end end to the start end.

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