Power transmission system, power transmission device, and power reception device

Abstract

To provide a power transmission system, a power transmission device, and a power reception device, in which the decrease in efficiency of the power transmission due to displacement of electrodes can be suppressed.SOLUTION: A first device and a second device are included. The first device includes a first electrode set and a rotary part. The first electrode set includes a first electrode and a second electrode disposed apart from each other. The rotary part can rotate the first electrode and the second electrode around a rotary axis that is not perpendicular to the first electrode and the second electrode. The second device includes a second electrode set including a third electrode and a fourth electrode disposed apart from each other, and electric field coupling occurs between the first electrode set and the second electrode set.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a power transmission system, a power transmission device, and a power reception device.

Background Art

[0002] There is a technique called electric field coupling type wireless power transmission that wirelessly transmits power by causing electric field coupling between two electrodes on the power transmission side and two electrodes on the power reception side. Electric field coupling type wireless power transmission is strong against misalignment other than in a specific direction of the electrodes. However, in electric field coupling type wireless power transmission, when the electrodes are misaligned in a specific direction, the power transmission efficiency decreases significantly compared to other directions.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The problem to be solved by the embodiments of the present invention is to provide a power transmission system, a power transmission device, and a power reception device that can suppress a decrease in power transmission efficiency due to electrode misalignment.

Means for Solving the Problems

[0005] The embodiment includes a first device and a second device. The first device includes a first electrode group and a rotating unit. The first electrode group includes a first electrode and a second electrode that are arranged at intervals. The rotating unit enables the first electrode and the second electrode to rotate about a rotation axis that is not perpendicular to the first electrode and the second electrode. The second device includes a third electrode and a fourth electrode that are arranged at intervals, and includes a second electrode group that causes electric field coupling with the first electrode group.

Effects of the Invention

[0006] According to the present invention, it is possible to suppress a decrease in the efficiency of power transmission due to displacement of electrodes.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Modes for Carrying Out the Invention

[0008] Hereinafter, a power transmission system according to several embodiments will be described with reference to the drawings. Note that the scales of the respective parts in the drawings used in the following description of the embodiments may be changed as appropriate. Also, the drawings used in the following description of the embodiments may show the configurations with some parts omitted for the purpose of explanation. In addition, in each of the drawings and this specification, the same reference numerals denote the same elements.

[0009] 〔First Embodiment〕 FIG. 1 is a diagram showing an example of a power transmission system according to the first embodiment. The power transmission system 1 includes, as an example, a power transmission device 100 and a power reception device 200. The power transmission system 1 transmits power from the power transmission device 100 to the power reception device 200 by electric field resonance type wireless power transmission.

[0010] The power transmission device 100 is a device that wirelessly transmits power to the power reception device 200. The power transmission device 100 includes, as an example, a power transmission coupler 110, a high-frequency power source 120, and a power transmission control unit 130.

[0011] The power transmission coupler 110 wirelessly transmits power to the power reception coupler 210 of the power reception device 200. The power transmission coupler 110 includes, as an example, a first power transmission electrode 111, a second power transmission electrode 112, and a first power transmission resonance coil 113. The power transmission coupler 110 includes, as an example, a box-shaped housing that houses, among other things, the first power transmission electrode 111, the second power transmission electrode 112, and the first power transmission resonance coil 113 inside.

[0012] The first power transmission electrode 111 and the second power transmission electrode 112 are, as an example, rectangular flat electrodes parallel to the surface of the power transmission coupler 110. Note that the surface of the power transmission coupler 110 is the side surface of the power transmission coupler 110 that faces the power reception coupler 210. The first power transmission electrode 111 and the second power transmission electrode 112 are, for example, of the same shape. The first power transmission electrode 111 and the second power transmission electrode 112 are arranged at intervals. The surfaces of the first power transmission electrode 111 and the second power transmission electrode 112 are, for example, on the same plane. The first power transmission electrode 111 and the second power transmission electrode 112 form a capacitor.

[0013] The first power transmission resonance coil 113 includes, for example, two coils, a primary coil and a secondary coil. The primary coil is connected to the high-frequency power source 120, as an example. The secondary coil is connected to the first power transmission electrode 111 and the second power transmission electrode 112, as an example. The first power transmission electrode 111, the second power transmission electrode 112, and the first power transmission resonance coil 113 form an LC circuit. This LC circuit is hereinafter referred to as the "first power transmission circuit".

[0014] The high-frequency power source 120 supplies AC power having the same frequency as the resonance frequency of the first power transmission circuit to the first power transmission circuit.

[0015] The power transmission control unit 130 includes a computer or the like that performs processes such as calculations and controls necessary for the operation of the power transmission device 100.

[0016] The power receiving device 200 is a device that receives power transmitted from the power transmitting device 100. The power receiving device 200 includes, as an example, a power receiving coupler 210, a rectifier circuit 220, a load 230, a power receiving control unit 240, and a rotating unit 250.

[0017] The power receiving coupler 210 receives the power transmitted from the power transmitting coupler 110 of the power transmitting device 100 and outputs it to the rectifier circuit 220. The power receiving coupler 210 includes, as an example, a first power receiving electrode 211, a second power receiving electrode 212, and a first power receiving resonance coil 213. The power receiving coupler 210 includes, as an example, a box-shaped housing that internally houses the first power receiving electrode 211, the second power receiving electrode 212, the first power receiving resonance coil 213, and the rotating unit 250. The housing is sized such that the first power receiving electrode 211 and the second power receiving electrode 212 can rotate inside. When the power transmitting coupler 110 and the power receiving coupler 210 are at a predetermined position (hereinafter referred to as the "predetermined position") for wireless power transmission, the power transmitting coupler 110 and the power receiving coupler 210 face each other in parallel. The predetermined position is a position where wireless transmission can be performed efficiently. If the positional relationship between the power transmitting coupler 110 and the power receiving coupler 210 deviates from the predetermined position, the efficiency of power transmission may decrease or power transmission may become impossible.

[0018] Incidentally, the predetermined position is, as an example, a position that satisfies the following first to fourth conditions. The first condition is that the first power transmission electrode 111 and the second power transmission electrode 112, and the first power reception electrode 211 and the second power reception electrode 212 are parallel and opposed to each other, and the power transmission coupler 110 and the power reception coupler 210 are parallel and opposed to each other. The second condition is that the straight line passing through the center of the first power transmission electrode 111 and the center of the second power transmission electrode 112, and the straight line passing through the center of the first power reception electrode 211 and the center of the second power reception electrode 212 are parallel. The third condition is that the distance between the first power transmission electrode 111 and the second power transmission electrode 112, and the first power reception electrode 211 and the second power reception electrode 212 is within a predetermined distance. In other words, the third condition is that the power transmission coupler 110 and the power reception coupler 210 are within a predetermined distance. The fourth condition is that the straight line passing through the midpoint of the line segment connecting the center of the first power transmission electrode 111 and the center of the second power transmission electrode 112, and the midpoint of the line segment connecting the center of the first power reception electrode 211 and the center of the second power reception electrode 212 is perpendicular to the straight line passing through the center of the first power transmission electrode 111 and the center of the second power transmission electrode 112, and the straight line passing through the center of the first power reception electrode 211 and the center of the second power reception electrode 212.

[0019] The first power reception electrode 211 and the second power reception electrode 212 are, as an example, rectangular flat electrodes parallel to the surface of the power reception coupler 210 when the power transmission coupler 110, the power reception coupler 210, the first power reception electrode 211, and the second power reception electrode 212 are in a predetermined position. Note that the surface of the power reception coupler 210 is the surface of the power reception coupler 210 on the side facing the power transmission coupler 110. The first power reception electrode 211 and the second power reception electrode 212 are, for example, the same shape. The first power reception electrode 211 is, for example, the same shape as the first power transmission electrode 111. The second power reception electrode 212 is, for example, the same shape as the second power transmission electrode 112. The first power reception electrode 211 and the second power reception electrode 212 are arranged at intervals. When the power transmission coupler 110 and the power reception coupler 210 are in a predetermined position, the first power reception electrode 211 faces the first power transmission electrode 111 at an interval. When the power transmission coupler 110 and the power reception coupler 210 are in a predetermined position, the second power reception electrode 212 faces the second power transmission electrode 112 at an interval. The first power reception electrode 211 and the second power reception electrode 212 form a capacitor.

[0020] The first power receiving resonant coil 213 includes, for example, two coils, a primary coil and a secondary coil. The primary coil is connected to the first power receiving electrode 211 and the second power receiving electrode 212 as an example. The secondary coil is connected to the rectifier circuit 220 as an example. The first power receiving electrode 211, the second power receiving electrode 212, and the first power receiving resonant coil 213 form an LC circuit. This LC circuit is hereinafter referred to as the "first power receiving circuit". Also, the first power receiving resonant coil 213 outputs the power received by the first power receiving electrode 211 and the second power receiving electrode 212 from the power transmission coupler 110 to the rectifier circuit 220.

[0021] When the power transmission coupler 110 and the power reception coupler 210 are at a predetermined position, by supplying AC power having the same frequency as the resonance frequency of the first power transmission circuit from the high-frequency power source 120, electric field resonance occurs between the first power transmission circuit and the first power reception circuit. Thereby, power is transmitted from the power transmission coupler 110 to the power reception coupler 210.

[0022] The rectifier circuit 220 rectifies the AC power output by the power reception coupler 210 into DC and outputs it to the load 230.

[0023] The load 230 is a part that consumes the power received by the power reception coupler 210. The load 230 consumes, for example, the DC power output from the rectifier circuit 220. The load 230 is, for example, various devices that operate by power. The load 230 is, for example, a battery. The battery is a secondary battery that is charged with the power received by the power reception coupler 210 and rectified by the rectifier circuit 220.

[0024] The power reception control unit 240 includes a computer or the like that performs processes such as operations and controls necessary for the operation of the power reception device 200.

[0025] The rotating unit 250 is, for example, a mechanism that rotates the first power receiving electrode 211 and the second power receiving electrode 212 in the rotation direction Rx about the rotation axis. The rotation axis passes through, for example, the midpoint of the line segment connecting the center of the first power receiving electrode 211 and the center of the second power receiving electrode 212. Also, the rotation axis is, for example, perpendicular to the line segment. Also, the rotation axis is, for example, parallel to the first power receiving electrode 211 and the second power receiving electrode 212. Also, the rotation axis is, for example, parallel to the x-axis when the power receiving device 200 is in a predetermined position. Note that the x-axis and the rotation direction Rx will be described later. The rotating unit 250 is composed of, for example, a driving unit such as a stepping motor or a servo motor capable of controlling the rotation angle, and a transmission mechanism that transmits the driving force of the driving unit to the first power receiving electrode 211 and the second power receiving electrode 212.

[0026] FIG. 2 is a block diagram showing the main part configuration of the power transmission control unit 130 and the power reception control unit 240. The power transmission control unit 130 includes, as an example, a processor 131, a ROM (read-only memory) 132, a RAM (random-access memory) 133, a communication interface 134, and a power transmission sensor 135.

[0027] Processor 131 is the central part of the power transmission control unit 130 and performs various operations and processes. Processor 131 is, for example, a CPU (central processing unit), MPU (micro processing unit), SoC (system on a chip), DSP (digital signal processor), GPU (graphics processing unit), ASIC (application specific integrated circuit), PLD (programmable logic device), or FPGA (field-programmable gate array), etc. Alternatively, processor 131 is a combination of a plurality of these. Also, processor 131 may be a combination of these with a hardware accelerator or the like. Processor 131 controls each part to realize various functions of the power transmission device 100 based on programs such as firmware, system software, and application software stored in ROM 132 and the like. Also, processor 131 executes the processes described later based on the program. Note that part or all of the program may be incorporated in the circuit of processor 131.

[0028] ROM 132 and RAM 133 are the main storage devices of the power transmission control unit 130. ROM 132 is a non-volatile memory used exclusively for reading data. ROM 132 stores the above programs and the like. Also, ROM 132 stores data and the like used by processor 131 when performing various processes. RAM 133 is a memory used for reading and writing data. RAM 133 is used as a work area or the like that stores data temporarily used by processor 131 when performing various processes. RAM 133 is typically a volatile memory.

[0029] Communication interface 134 is an interface for the power transmission device 100 to communicate with the power reception device 200.

[0030] The power transmission sensor 135 is a sensor for measuring the power transmission efficiency of the power transmission coupler 110.

[0031] The power reception control unit 240 includes, as an example, a processor 241, a ROM 242, a RAM 243, a communication interface 244, and a power reception sensor 245.

[0032] The processor 241 is the central part of the power reception control unit 240 and performs various operations and processes. The processor 241 is, for example, a CPU, MPU, SoC, DSP, GPU, ASIC, PLD, or FPGA, etc. Alternatively, the processor 241 is a combination of a plurality of these. Also, the processor 241 may be a combination of these with a hardware accelerator, etc. The processor 241 controls each part to realize various functions of the power reception device 200 based on programs such as firmware, system software, and application software stored in the ROM 242, etc. Also, the processor 241 executes the processes described later based on the program. Note that part or all of the program may be incorporated into the circuit of the processor 241.

[0033] The ROM 242 and the RAM 243 are the main storage devices of the power reception control unit 240. The ROM 242 is a non-volatile memory used exclusively for reading data. The ROM 242 stores the above programs, etc. Also, the ROM 242 stores data, etc. used by the processor 241 when performing various processes. The RAM 243 is a memory used for reading and writing data. The RAM 243 is used as a work area, etc. for storing data temporarily used by the processor 241 when performing various processes. The RAM 243 is typically a volatile memory.

[0034] The communication interface 244 is an interface for the power receiving device 200 to communicate with the power transmitting device 100. The power receiving device 200 communicates with the power transmitting device 100, for example, by wireless communication.

[0035] The power receiving sensor 245 is a sensor for measuring the power receiving efficiency of the power receiving coupler 210.

[0036] Note that FIG. 1 shows the x-axis, y-axis, and z-axis. The x-axis direction is perpendicular to the y-axis direction and the z-axis direction. The y-axis direction is, for example, when the power transmitting device 100 and the power receiving device 200 are in predetermined positions, the straight line direction connecting the midpoint of the line segment connecting the center of the first power transmitting electrode 111 and the center of the second power transmitting electrode 112, and the midpoint of the line segment connecting the center of the first power receiving electrode 211 and the center of the second power receiving electrode 212, and is perpendicular to the surface of the power transmitting coupler 110. The z-axis direction is the direction connecting the center of the first power transmitting electrode 111 and the center of the second power transmitting electrode 112. Also, FIG. 1 shows the rotation direction Rx, the rotation direction Ry, and the rotation direction Rz. The rotation direction Rx is a rotation direction that rotates in the right-hand screw direction with a straight line parallel to the x-axis as the rotation axis. The rotation direction Ry is a rotation direction that rotates in the right-hand screw direction with a straight line parallel to the y-axis as the rotation axis. The rotation direction Rz is a rotation direction that rotates in the right-hand screw direction with a straight line parallel to the z-axis as the rotation axis. The x-axis, y-axis, and z-axis, as well as the rotation direction Rx, the rotation direction Ry, and the rotation direction Rz, are shown in addition to FIG. 1, and all figures show the same coordinate system and rotation directions.

[0037] Next, the operation of the power transmission system 1 according to the first embodiment will be described with reference to FIG. 3 and the like. Note that the content of the processing in the following operation description is an example, and various processes capable of obtaining the same result can be appropriately used. FIG. 3 is a flowchart showing an example of the processing by the processor 241 of the power reception control unit 240. The processor 241 executes the processing of FIG. 3 based on a program stored in, for example, the ROM 242. The processor 241 starts the processing of FIG. 3 when, for example, the distance between the power transmission coupler 110 and the power reception coupler 210 becomes equal to or less than a predetermined distance. Alternatively, the processor 241 starts the processing of FIG. 3 in response to the start of power transmission from the power transmission coupler 110 to the power reception coupler 210. Further, the processor 241 may start the processing of FIG. 3 when the power transmission efficiency (power reception efficiency) of the wireless power transmission by the power transmission coupler 110 changes by a predetermined amount or more. Further, the processor 241 may start the processing of FIG. 3 when the position of the power reception coupler 210 with respect to the power transmission coupler 110 changes by a predetermined amount or more. Further, the processor 241 may start the processing of FIG. 3 at predetermined time intervals.

[0038] In step ST11, the processor 241 of the power reception device 200 controls the rotating unit 250 to rotate the first power reception electrode 211 and the second power reception electrode 212, thereby setting the rotation positions of the first power reception electrode 211 and the second power reception electrode 212 at various angles and obtaining the power transmission efficiency for each rotation position. The processor 241 obtains the power transmission efficiency using, for example, information output from at least one of the power transmission sensor 135 and the power reception sensor 245. Note that the processor 131 of the power transmission device 131 transmits the information output from the power transmission sensor 135 from the power transmission device 100 to the power reception device 200 via the communication interface 134 and the communication interface 244.

[0039] In step ST12, the processor 241 determines the angles of the rotation positions of the first power reception electrode 211 and the second power reception electrode 212. The processor 241 determines, for example, the angle at which the power transmission efficiency was the best in step ST11 as the angles of the rotation positions of the first power reception electrode 211 and the second power reception electrode 212.

[0040] In step ST13, the processor 241 controls the rotating part 250 to rotate the angles of the rotational positions of the first power receiving electrode 211 and the second power receiving electrode 212 to the angles determined in step ST12. After the process of step ST13, the processor 241 ends the process shown in FIG. 3. FIG. 4 is a diagram showing the rotation states of the first power receiving electrode 211 and the second power receiving electrode 212. FIG. 4 is a plan view of the power transmission coupler 110 and the power receiving coupler 210 as viewed from the x direction. Note that FIG. 4 omits the illustration of parts other than the first power transmission electrode 111, the second power transmission electrode 112, the first power receiving electrode 211, the second power receiving electrode 212, and the rotating part 250. Also, the power receiving coupler 210 shown in FIG. 4 is at a position shifted in the z direction from a predetermined position. In this case, by performing the process of step ST13, the processor 241 makes the angles of the rotational positions of the first power receiving electrode 211 and the second power receiving electrode 212, for example, θ as shown in FIG. 4. Thereby, the power transmission efficiency is increased compared to the case where the angles of the rotational positions of the first power receiving electrode 211 and the second power receiving electrode 212 are 0 degrees. Note that for the rotational position, any position can be defined as 0 degrees. In FIG. 4, as an example, the angle when the first power receiving electrode 211 and the second power receiving electrode 212 are parallel to the z axis is defined as 0 degrees. In this way, by rotating the first power receiving electrode 211 and the second power receiving electrode 212 in the rotational direction Rx, the power transmission system 1 can increase the power transmission efficiency when the position of the power receiving coupler 210 with respect to the power transmission coupler 110 is shifted in the z direction from a predetermined position.

[0041] As described above, by performing the process shown in FIG. 3, the processor 241 determines the angles of the rotational positions of the first power receiving electrode 211 and the second power receiving electrode 212 based on the power transmission efficiency, and functions as an example of a control unit that controls the rotating part 250 so that the rotational positions of the first power receiving electrode 211 and the second power receiving electrode 212 are at the angles.

[0042] In the power transmission system 1 of the first embodiment, the first power receiving electrode 211 and the second power receiving electrode 212 are rotatable. Therefore, in the power transmission system 1 of the first embodiment, it is possible to set the rotational positions of the first power receiving electrode 211 and the second power receiving electrode 212 to angles at which the power transmission efficiency is high.

[0043] Also, the power transmission system 1 of the first embodiment determines the angles of the rotational positions of the first power receiving electrode 211 and the second power receiving electrode 212 based on the power transmission efficiency. Thereby, the power transmission system 1 of the first embodiment can increase the power transmission efficiency.

[0044] Also, the power transmission system 1 of the first embodiment determines the angles of the rotational positions of the first power receiving electrode 211 and the second power receiving electrode 212 to the angles at which the power transmission efficiency is the highest. Thereby, the power transmission system 1 of the first embodiment can increase the power transmission efficiency.

[0045] Also, in the power transmission system 1 of the first embodiment, the rotation axis of the rotating part 250 is parallel to the x-axis. For this reason, the first power receiving electrode 211 and the second power receiving electrode 212 are rotatable in the rotation direction Rx. Thereby, when the position of the power receiving coupler 210 with respect to the power transmission coupler 110 is shifted in the z direction from the predetermined position, the power transmission system 1 of the first embodiment can increase the power transmission efficiency by the rotation of the first power receiving electrode 211 and the second power receiving electrode 212. Also, when the position of the power receiving coupler 210 with respect to the power transmission coupler 110 is shifted in the rotation direction Rx from the predetermined position, the power transmission system 1 of the first embodiment can increase the power transmission efficiency by the rotation of the first power receiving electrode 211 and the second power receiving electrode 212.

[0046] Note that in the first embodiment, the power receiving device 200 is an example of a first device. The power transmitting device 100 is an example of a second device. The first power receiving electrode 211 is an example of a first electrode. The second power receiving electrode 212 is an example of a second electrode. The first power receiving electrode 211 and the second power receiving electrode 212 are an example of a first electrode group. The first power transmitting electrode 111 is an example of a third electrode. The second power transmitting electrode 112 is an example of a fourth electrode. The first power transmitting electrode 111 and the second power transmitting electrode 112 are an example of a second electrode group. The straight line passing through the centers of the first power receiving electrode 211 and the second power receiving electrode 212 is an example of a first straight line.

[0047] 〔Second Embodiment〕 FIG. 5 is a diagram showing an example of a power transmission system 1b according to the second embodiment. The parts of the power transmission system 1b that are different from the power transmission system 1 according to the first embodiment will be described. The power transmission system 1b includes, as an example, a power transmitting device 100b and a power receiving device 200b. That is, the power transmission system 1b includes the power transmitting device 100b instead of the power transmitting device 100 and the power receiving device 200b instead of the power receiving device 200. Note that FIG. 5 omits the illustration of the first power transmission resonance coil 113, the high-frequency power supply 120, the power transmission control unit 130, the first power reception resonance coil 213, the rectifier circuit 220, the load 230, and the power reception control unit 240.

[0048] The power transmitting device 100b includes, as an example, a power transmission coupler 110b, a high-frequency power supply 120, a power transmission control unit 130, and a rotating unit 140. That is, the power transmitting device 100b includes the rotating unit 140 in addition to the components of the power transmitting device 100 of the first embodiment. Further, the power transmitting device 100b includes the power transmission coupler 110b instead of the power transmission coupler 110.

[0049] The power transmission coupler 110b wirelessly transmits power to the power reception coupler 210b. The housing of the power transmission coupler 110b is sized such that the first power transmitting electrode 111 and the second power transmitting electrode 112 can rotate inside.

[0050] The rotating unit 140 is, for example, a mechanism that rotates the first power transmission electrode 111 and the second power transmission electrode 112 in the rotation direction Rx about the rotation axis. The rotation axis passes through, for example, the midpoint of the line segment connecting the center of the first power transmission electrode 111 and the center of the second power transmission electrode 112. Further, the rotation axis is, for example, perpendicular to the line segment. Further, the rotation axis is, for example, parallel to the first power transmission electrode 111 and the second power transmission electrode 112. Further, the rotation axis is, for example, parallel to the x-axis when the power receiving device 200 is in a predetermined position. The rotating unit 140 is constituted by, for example, a driving unit such as a stepping motor or a servo motor capable of controlling the rotation angle, and a transmission mechanism that transmits the driving force of the driving unit to the first power transmission electrode 111 and the second power transmission electrode 112.

[0051] The power receiving device 200b includes, as an example, a power receiving coupler 210b, a rectifier circuit 220, a load 230, and a power receiving control unit 240. That is, unlike the power receiving device 200 of the first embodiment, the power receiving device 200b does not have a rotating unit 250. Further, the power receiving device 200b includes a power receiving coupler 210b instead of the power receiving coupler 210.

[0052] The power receiving coupler 210b receives the power transmitted from the power transmission coupler 110b and outputs it to the rectifier circuit 220. The housing of the power receiving coupler 210b does not need to be sized such that the first power receiving electrode 211 and the second power receiving electrode 212 can rotate inside.

[0053] Next, the operation of the power transmission system 1b according to the second embodiment will be described with reference to FIG. 3 and the like. Note that the content of the processing in the following operation description is an example, and various processes capable of obtaining the same results can be appropriately used. In the second embodiment, instead of the processor 241 of the power reception control unit 240, the processor 131 of the power transmission control unit 130 performs the processing shown in FIG. 3. Therefore, in the second embodiment, FIG. 3 is a flowchart showing an example of the processing by the processor 131 of the power transmission control unit 130. The processor 131 starts the processing of FIG. 3, for example, when the distance between the power transmission coupler 110 and the power reception coupler 210 becomes equal to or less than a predetermined distance. Alternatively, the processor 131 starts the processing of FIG. 3 in response to the start of power transmission from the power transmission coupler 110 to the power reception coupler 210. Further, the processor 131 may start the processing of FIG. 3 when the power transmission efficiency (power reception efficiency) of the wireless power transmission by the power transmission coupler 110 changes by a predetermined amount or more. Further, the processor 131 may start the processing of FIG. 3 when the position of the power reception coupler 210 with respect to the power transmission coupler 110 changes by a predetermined amount or more. Further, the processor 131 may start the processing of FIG. 3 at predetermined time intervals.

[0054] In step ST11, the processor 131 of the power transmission device 100b controls the rotating unit 140 to rotate the first power transmission electrode 111 and the second power transmission electrode 112, thereby setting the rotational positions of the first power transmission electrode 111 and the second power transmission electrode 112 at various angles and obtaining the power transmission efficiency for each rotational position. The processor 131 obtains the power transmission efficiency, for example, using the information output by at least one of the power transmission sensor 135 and the power reception sensor 245. Note that the processor 231 of the power reception device 200b transmits the information output by the power reception sensor 245 from the power reception device 200b to the power transmission device 100b via the communication interface 244 and the communication interface 134.

[0055] In step ST12, the processor 131 determines the angles of the rotational positions of the first power transmission electrode 111 and the second power transmission electrode 112. For example, the processor 131 determines, as the angles of the rotational positions of the first power transmission electrode 111 and the second power transmission electrode 112, the angles at which the power transmission efficiency was the best in step ST11.

[0056] In step ST13, the processor 131 controls the rotating unit 250 to rotate the angles of the rotational positions of the first power transmission electrode 111 and the second power transmission electrode 112 to the angles determined in step ST12. After the process of step ST13, the processor 131 ends the process shown in FIG. 3.

[0057] Unlike the first embodiment, in the power transmission system 1b of the second embodiment, the first power transmission electrode 111 and the second power transmission electrode 112 are rotatable instead of the first power reception electrode 211 and the second power reception electrode 212. Thereby, the power transmission system 1b of the second embodiment can obtain the same effects as the power transmission system 1 of the first embodiment.

[0058] Note that in the second embodiment, the power transmission device 100b is an example of the first device. The power reception device 200b is an example of the second device. The first power transmission electrode 111 is an example of the first electrode. The second power transmission electrode 112 is an example of the second electrode. The first power transmission electrode 111 and the second power transmission electrode 112 are an example of the first electrode group. The first power reception electrode 211 is an example of the third electrode. The second power reception electrode 212 is an example of the fourth electrode. The first power reception electrode 211 and the second power reception electrode 212 are an example of the second electrode group. The straight line passing through the centers of the first power transmission electrode 111 and the second power transmission electrode 112 is an example of the first straight line.

[0059] 〔Third Embodiment〕 FIG. 6 is a diagram showing an example of the power transmission system 1c according to the third embodiment. The parts of the power transmission system 1c that are different from the power transmission system 1 according to the first embodiment will be described. The power transmission system 1c includes, as an example, a power transmission device 100 and a power reception device 200c. That is, the power transmission system 1c includes the power reception device 200c instead of the power reception device 200. Note that FIG. 6 omits the illustration of the high-frequency power supply 120, the power transmission control unit 130, the rectifier circuit 220, the load 230, and the power reception control unit 240.

[0060] The power reception device 200c includes, as an example, a power reception coupler 210c, a rectifier circuit 220, a load 230, a power reception control unit 240, and a rotating unit 250b. That is, the power reception device 200c includes the power reception coupler 210c instead of the power reception coupler 210, and includes the rotating unit 250b instead of the rotating unit 250.

[0061] The power reception coupler 210c receives the power transmitted from the power transmission coupler 110 and outputs it to the rectifier circuit 220. The power reception coupler 210c includes, as an example, a first power reception electrode 211, a second power reception electrode 212, a first power reception resonance coil 213, a third power reception electrode 214, a fourth power reception electrode 215, and a second power reception resonance coil 216. The power reception coupler 210c includes, as an example, a box-shaped housing that internally includes the first power reception electrode 211, the second power reception electrode 212, the first power reception resonance coil 213, and the rotating unit 250b. The housing is sized such that the first power reception electrode 211, the second power reception electrode 212, the third power reception electrode 214, and the fourth power reception electrode 215 can rotate inside.

[0062] The third power receiving electrode 214 and the fourth power receiving electrode 215 are, as an example, flat rectangular electrodes perpendicular to the surface of the power receiving coupler 210c when the power transmission coupler 110, the power receiving coupler 210c, the first power receiving electrode 211, and the second power receiving electrode 212 are at predetermined positions. The third power receiving electrode 214 and the fourth power receiving electrode 215 are, for example, in positions perpendicular to the first power receiving electrode 211 and the second power receiving electrode 212. The third power receiving electrode 214 has, for example, the same shape as the fourth power receiving electrode 215. The third power receiving electrode 214 and the fourth power receiving electrode 215 have, for example, the same shape as the first power receiving electrode 211 and the second power receiving electrode 212. The third power receiving electrode 214 and the fourth power receiving electrode 215 are arranged with a gap therebetween. However, the gap between the third power receiving electrode 214 and the fourth power receiving electrode 215 may be different from or the same as the gap between the first power receiving electrode 211 and the second power receiving electrode 212. The third power receiving electrode 214 and the fourth power receiving electrode 215 form a capacitor. The position of the straight line passing through the center of the third power receiving electrode 214 and the center of the fourth power receiving electrode 215 is at a position where the straight line passing through the center of the first power receiving electrode 211 and the center of the second power receiving electrode 212 is rotated 90 degrees or -90 degrees in the rotation direction Rx degree or at a position shifted in the y direction from that position. The center of rotation of the rotation is, for example, the midpoint of the line segment connecting the center of the first power receiving electrode 211 and the center of the second power receiving electrode 212. The third power receiving electrode 214 and the fourth power receiving electrode 215 are, for example, at positions where the first power receiving electrode 211 and the second power receiving electrode 212 are rotated 90 degrees or -90 degrees in the rotation direction Rx. The center of rotation of the rotation is, for example, the midpoint of the line segment connecting the center of the first power receiving electrode 211 and the center of the second power receiving electrode 212. Therefore, in the power receiving coupler 210c, the four power receiving electrodes are arranged at equal angles with a 90-degree interval therebetween.

[0063] The second power receiving resonant coil 216 includes, for example, two coils: a primary coil and a secondary coil. The primary coil is connected to the third power receiving electrode 214 and the fourth power receiving electrode 215 as an example. The secondary coil is connected to the rectifier circuit 220 as an example. The third power receiving electrode 214, the fourth power receiving electrode 215, and the second power receiving resonant coil 216 form an LC circuit. This LC circuit is hereinafter referred to as the "second power receiving circuit". Also, the second power receiving resonant coil 216 outputs the power received by the third power receiving electrode 214 and the fourth power receiving electrode 215 from the power transmission coupler 110 to the rectifier circuit 220.

[0064] If at least one of the two electric field resonances, i.e., the electric field resonance between the first power transmission circuit and the first power receiving circuit and the electric field resonance between the first power transmission circuit and the second power receiving circuit, occurs in the power transmission system 1c, power is transmitted from the power transmission coupler 110 to the power receiving coupler 210c.

[0065] The rotating part 250b is a mechanism that rotates the third power receiving electrode 214 and the fourth power receiving electrode 215 in the rotational direction Rx about the rotation axis in addition to the first power receiving electrode 211 and the second power receiving electrode 212. The rotation axis is the same as that in the first embodiment, for example.

[0066] The power transmission system 1c of the third embodiment can obtain the same effects as the power transmission system 1 of the first embodiment. Also, since the power transmission system 1c of the third embodiment includes a second power receiving circuit, the rotational positions of the first power receiving electrode 211, the second power receiving electrode 212, the third power receiving electrode 214, and the fourth power receiving electrode 215 can be set to positions with high power transmission efficiency at a smaller rotation angle than the power transmission system 1 of the first embodiment. Also, the power transmission system 1c of the third embodiment can achieve higher power transmission efficiency than the power transmission system 1 of the first embodiment.

[0067] Note that in the third embodiment, the third power receiving electrode 214 is an example of the fifth electrode. The fourth power receiving electrode 215 is an example of the sixth electrode. The third power receiving electrode 214 and the fourth power receiving electrode 215 are an example of the third electrode group. A straight line passing through the center of the third power receiving electrode 214 and the center of the fourth power receiving electrode 215 is an example of the second straight line.

[0068] 〔Fourth Embodiment〕 FIG. 7 is a diagram showing an example of the power transmission system 1d according to the fourth embodiment. Differences between the power transmission system 1d and the power transmission system 1b according to the second embodiment will be described. The power transmission system 1d includes, as an example, a power transmission device 100c and a power reception device 200b. That is, the power transmission system 1d includes the power transmission device 100c instead of the power transmission device 100b. Note that FIG. 7 omits illustration of the high-frequency power supply 120, the power transmission control unit 130, the rectifier circuit 220, the load 230, and the power reception control unit 240.

[0069] The power transmission device 100c includes, as an example, a power transmission coupler 110c, a high-frequency power supply 120, a power transmission control unit 130, and a rotating unit 140b. That is, the power transmission device 100c includes the power transmission coupler 110c instead of the power transmission coupler 110b and includes the rotating unit 140b instead of the rotating unit 140.

[0070] The power transmission coupler 110c wirelessly transmits power to the power reception coupler 210. The power transmission coupler 110c includes, as an example, a first power transmission electrode 111, a second power transmission electrode 112, a first power transmission resonance coil 113, a third power transmission electrode 114, a fourth power transmission electrode 115, and a second power transmission resonance coil 116. The power transmission coupler 110c includes, as an example, a box-shaped housing that internally houses the first power transmission electrode 111, the second power transmission electrode 112, the first power transmission resonance coil 113, and the rotating unit 140b. The housing is sized such that the first power transmission electrode 111, the second power transmission electrode 112, the third power transmission electrode 114, and the fourth power transmission electrode 115 can rotate inside.

[0071] The third power transmission electrode 114 and the fourth power transmission electrode 115 are, as an example, flat rectangular electrodes perpendicular to the surface of the power transmission coupler 110c when the power transmission coupler 110, the power reception coupler 210c, the first power transmission electrode 111, and the second power transmission electrode 112 are at predetermined positions. The third power transmission electrode 114 and the fourth power transmission electrode 115 are, for example, in a position perpendicular to the first power transmission electrode 111 and the second power transmission electrode 112. The third power transmission electrode 114 is, for example, the same shape as the fourth power transmission electrode 115. The third power transmission electrode 114 and the fourth power transmission electrode 115 are, for example, the same shape as the first power transmission electrode 111 and the second power transmission electrode 112. The third power transmission electrode 114 and the fourth power transmission electrode 115 are arranged with a gap therebetween. However, the gap between the third power transmission electrode 114 and the fourth power transmission electrode 115 may be different from or the same as the gap between the first power transmission electrode 111 and the second power transmission electrode 112. The third power transmission electrode 114 and the fourth power transmission electrode 115 form a capacitor. The position of the straight line passing through the center of the third power transmission electrode 114 and the center of the fourth power transmission electrode 115 is 90 degrees or -90 degrees in the rotation direction Rx with respect to the straight line passing through the center of the first power transmission electrode 111 and the center of the second power transmission electrode 112. degree It is at a rotated position or a position shifted in the y direction from that position. The center of rotation of the rotation is, for example, the midpoint of the line segment connecting the center of the first power transmission electrode 111 and the center of the second power transmission electrode 112. The third power transmission electrode 114 and the fourth power transmission electrode 115 are, for example, at a position rotated 90 degrees or -90 degrees in the rotation direction Rx with respect to the first power transmission electrode 111 and the second power reception electrode. degree It is at a rotated position. The center of rotation of the rotation is, for example, the midpoint of the line segment connecting the center of the first power transmission electrode 111 and the center of the second power transmission electrode 112. Therefore, in the power transmission coupler 110b, the four power transmission electrodes are arranged at equal angles with a 90-degree interval therebetween.

[0072] The second power transmission resonance coil 116 includes, for example, two coils: a primary coil and a secondary coil. The primary coil is connected to a high-frequency power supply 120 as an example. The secondary coil is connected to a third power transmission electrode 114 and a fourth power transmission electrode 115 as an example. The third power transmission electrode 114, the fourth power transmission electrode 115, and the second power transmission resonance coil 116 form an LC circuit. This LC circuit is hereinafter referred to as the "second power transmission circuit". The high-frequency power supply 120 supplies power to the first power transmission circuit and the second power transmission circuit. Note that the high-frequency power supply 120 supplies AC power having the same frequency as the resonance frequency of the second power transmission circuit to the second power transmission circuit.

[0073] If at least one of the two electric field resonances, i.e., the electric field resonance between the first power transmission circuit and the first power reception circuit and the electric field resonance between the second power transmission circuit and the first power reception circuit, occurs in the power transmission system 1c, power is transmitted from the power transmission coupler 110b to the power reception coupler 210.

[0074] The rotating part 140b is a mechanism that rotates the third power transmission electrode 114 and the fourth power transmission electrode 115 in the rotation direction Rx about the rotation axis, in addition to the first power transmission electrode 111 and the second power transmission electrode 112. The rotation axis is the same as that in the second embodiment, for example.

[0075] The power transmission system 1d of the fourth embodiment has the same effects as the power transmission system 1b of the second embodiment. In addition, since the power transmission system 1d of the fourth embodiment includes a second power transmission circuit, the rotation positions of the first power transmission electrode 111, the second power transmission electrode 112, the third power transmission electrode 114, and the fourth power transmission electrode 115 can be set to positions with high power transmission efficiency at a smaller rotation angle than the power transmission system 1b of the second embodiment. Also, the power transmission system 1d of the fourth embodiment can achieve higher power transmission efficiency than the power transmission system 1b of the second embodiment.

[0076] In addition, in the fourth embodiment, the third power transmission electrode 114 is an example of a fifth electrode. The fourth power transmission electrode 115 is an example of a sixth electrode. The third power transmission electrode 114 and the fourth power transmission electrode 115 are an example of a third electrode group. A straight line passing through the center of the third power transmission electrode 114 and the center of the fourth power transmission electrode 115 is an example of a second straight line.

[0077] The above embodiments can be modified as follows. The power transmission system of the embodiment may include the power transmission device 100b or the power transmission device 100c, and the power reception device 200 or the power reception device 200c. That is, in the power transmission system of the embodiment, both the power transmission device and the power reception device may include a rotating part.

[0078] In the above embodiment, the first power transmission electrode 111 and the second power transmission electrode 112 rotate within the housing of the power transmission coupler 110b. However, in the power transmission device of the embodiment, the rotating part may be configured to rotate the housing of the power reception coupler 210 that has the first power transmission electrode 111 and the second power transmission electrode 112 inside. In this case, the first power transmission electrode 111 and the second power transmission electrode 112 rotate together with the housing. In the above embodiment, the first power reception electrode 211 and the second power reception electrode 212 rotate within the housing of the power reception coupler 210. However, in the power reception device of the embodiment, the rotating part may be configured to rotate the housing of the power reception coupler 210 that has the first power reception electrode 211 and the second power reception electrode 212 inside. In this case, the first power reception electrode 211 and the second power reception electrode 212 rotate together with the housing.

[0079] In the above embodiment, the rotation axes of the rotating part 140 and the rotating part 250 are parallel to the x-axis. However, each of the rotation axes of the rotating part 140 and the rotating part 250 does not have to be parallel to the x-axis. However, the rotation axes of the rotating part 140 and the rotating part 250 are not perpendicular to the x-axis. When the rotation axis of the rotating part 140 is not perpendicular to the x-axis, the rotation of the first power transmission electrode 111 and the second power transmission electrode 112 includes a rotation direction Rx component. When the rotation axis of the rotating part 250 is not perpendicular to the x-axis, the rotation of the first power reception electrode 211 and the second power reception electrode 212 includes a rotation direction Rx component.

[0080] In the above embodiment, the rotation axis of the rotating part 140 passes through the midpoint of the line segment connecting the center of the first power transmission electrode 111 and the center of the second power transmission electrode 112. However, the rotation axis may be at a position that does not pass through the midpoint. Even in this case, the first power transmission electrode 111 and the second power transmission electrode 112 are rotatable in the rotation direction Rx. In the above embodiment, the rotation axis of the rotating part 250 passes through the midpoint of the line segment connecting the center of the first power receiving electrode 211 and the center of the second power receiving electrode 212. However, the rotation axis may be at a position that does not pass through the midpoint. Even in this case, the first power receiving electrode 211 and the second power receiving electrode 212 are rotatable in the rotation direction Rx.

[0081] The rotating part 140 and the rotating part 250 may be rotatable manually. In this case, an operator of the power transmission system can manually rotate the first power transmission electrode 111 and the second power transmission electrode 112, or the first power receiving electrode 211 and the second power receiving electrode 212 to a position with good power transmission efficiency while checking the power transmission efficiency.

[0082] In the power receiving device 200c in the above embodiment, the position of the straight line passing through the centers of the third power receiving electrode 214 and the fourth power receiving electrode 215 is rotated 90 degrees or -90 degrees in the rotation direction Rx with respect to the straight line passing through the centers of the first power receiving electrode 211 and the second power receiving electrode 212. degree It is at a position where it is rotated or shifted in the y direction from that position. However, the angle may be an angle other than 90 degrees and -90 degrees. However, the angle is an angle other than 0 degrees and 180 degrees. That is, the straight line (the second straight line) passing through the centers of the third power receiving electrode 214 and the fourth power receiving electrode 215 and the straight line (the first straight line) passing through the centers of the first power receiving electrode 211 and the second power receiving electrode 212 are not parallel. Also, the angle is preferably 90 degrees or -90 degrees.

[0083] In the power transmission device 100c in the above embodiment, the position of the straight line passing through the centers of the third power transmission electrode 114 and the fourth power transmission electrode 115 is such that the straight line passing through the centers of the first power transmission electrode 111 and the second power transmission electrode 112 is rotated 90 degrees or -90 degree degrees in the rotation direction Rx or is shifted in the y direction from that position. However, the angle may be an angle other than 90 degrees and -90 degrees. However, the angle is an angle other than 0 degrees and 180 degrees. That is, the straight line (second straight line) passing through the centers of the third power transmission electrode 114 and the fourth power transmission electrode 115 and the straight line (first straight line) passing through the centers of the first power transmission electrode 111 and the second power transmission electrode 112 are not substantially parallel. Also, the angle is preferably 90 degrees or -90 degrees.

[0084] In the above embodiment, each electrode is a rectangular flat plate-shaped electrode. However, each electrode may have a shape other than a rectangle. For example, the shape of each electrode is a polygonal shape such as a triangle, a circle, or other planar graphic-shaped flat plate electrodes. Also, each electrode does not have to be a flat plate-shaped electrode. For example, each electrode may be a column, a cone, a sphere, or other three-dimensional graphic shapes. Also, each electrode may have a shape such that the flat plate is curved.

[0085] In the above embodiment, the power transmission device 100c and the power reception device 200c include two LC circuits each consisting of two electrodes and a resonance coil. However, at least one of the power reception device and the power transmission device in the embodiment may include three or more LC circuits.

[0086] The third power transmission electrode 114 and the fourth power transmission electrode 115 may be at positions different from those shown in the above embodiment. The third power reception electrode 214 and the fourth power reception electrode 215 may be at positions different from those shown in the above embodiment.

[0087] As an example, the power transmission device of the embodiment may include a first power transmission circuit and two second power transmission circuits. In this case, for one of the second power transmission circuits, the position of the straight line passing through the centers of the third power transmission electrode 114 and the fourth power transmission electrode 115 is at a position where the straight line passing through the centers of the first power transmission electrode 111 and the second power transmission electrode 112 is rotated by θ degrees in the rotation direction Rx or at a position shifted in the y direction from that position. And for the other second power transmission circuit, the position of the straight line passing through the centers of the third power transmission electrode 114 and the fourth power transmission electrode 115 is at a position where the straight line passing through the centers of the first power transmission electrode 111 and the second power transmission electrode 112 is rotated by φ degrees in the rotation direction Rx or at a position shifted in the y direction from that position. Note that θ1≠φ1, 0<θ1<180, 0<φ1<180. As an example, θ1 = 60 and φ1 = 120. In this case, six power transmission electrodes are arranged at equal angles with an interval of 60 degrees. Also, the power transmission device may include a first power transmission circuit and three or more second power transmission circuits.

[0088] As an example, the power reception device of the embodiment may include a first power reception circuit and two second power reception circuits. In this case, for one of the second power reception circuits, the position of the straight line passing through the centers of the third power reception electrode 214 and the fourth power reception electrode 215 is at a position where the straight line passing through the centers of the first power reception electrode 211 and the second power reception electrode 212 is rotated by θ2 degrees in the rotation direction Rx or at a position shifted in the y direction from that position. And for the other second power reception circuit, the position of the straight line passing through the centers of the third power reception electrode 214 and the fourth power reception electrode 215 is at a position where the straight line passing through the centers of the first power reception electrode 211 and the second power reception electrode 212 is rotated by φ2 degrees in the rotation direction Rx or at a position shifted in the y direction from that position. Note that θ2≠φ2, 0<θ2<180, 0<φ2<180. As an example, θ2 = 60 and φ2 = 120. In this case, six power reception electrodes are arranged at equal angles with an interval of 60 degrees. Also, the power reception device may include a first power reception circuit and three or more second power reception circuits.

[0089] In the above-described embodiment, the first power transmission electrode 111, the second power transmission electrode 112, the third power transmission electrode 114, the fourth power transmission electrode 115, the first power reception electrode 211, the second power reception electrode 212, the third power reception electrode 214, and the fourth power reception electrode 215 are all of the same shape. However, at least one or more of these electrodes may have a shape different from that of the other electrodes.

[0090] In the above-described embodiment, the power transmission system transmits power by electric field resonance. However, the power transmission system of the embodiment may transmit power by electric field coupling that is not electric field resonance. Further, the power transmission system of the embodiment may have a mixture of power transmission by electric field coupling that is not electric field resonance and power transmission by electric field resonance.

[0091] The processor 131 and the processor 141 may implement part or all of the processing realized by the program in the above-described embodiment by the hardware configuration of the circuit.

[0092] The program for realizing the processing of the embodiment is transferred, for example, in a state stored in the device. However, the device may be transferred in a state where the program is not stored. And the program may be transferred separately and written into the device. The transfer of the program at this time can be realized, for example, by recording on a removable storage medium or by downloading via a network such as the Internet or a LAN (local area network).

[0093] The embodiments of the present invention have been described above, but are shown as examples and do not limit the scope of the present invention. The embodiments of the present invention can be implemented in various modes without departing from the gist of the present invention.

Description of Reference Numerals

[0094] 1, 1b, 1c, 1d Power transmission system 100, 100b, 100c Power transmission device 110, 110b, 110c Power transmission coupler 111 First power transmission electrode 112 Second power transmission electrode 113 First power transmission resonance coil 114 Third power transmission electrode 115 Fourth power transmission electrode 116 Second power transmission resonance coil 120 High-frequency power source 130 Power transmission control unit 131, 241 Processor 132, 242 ROM 133, 243 RAM 134, 244 Communication interface 135 Power transmission sensor 140, 250 Rotating part 200, 200b, 200c Power receiving device 210, 210b, 210c Power receiving coupler 211 First power receiving electrode 212 Second power receiving electrode 213 First power receiving resonance coil 214 Third power receiving electrode 215 Fourth power receiving electrode 216 Second power receiving resonance coil 220 Rectifier circuit 230 Load 240 Power receiving control unit 245 Power receiving sensor

Claims

1. comprising a first device and a second device, wherein the first device comprises a first electrode set including a first electrode and a second electrode arranged at intervals, and a rotating part for rotatably arranging the first electrode and the second electrode about a rotation axis that is not perpendicular to the first electrode and the second electrode, wherein the second device comprises a second electrode set including a third electrode and a fourth electrode arranged at intervals, and electric field coupling occurs between the second electrode set and the first electrode set, the rotation axis is perpendicular to a first straight line passing through the centers of the first electrode and the second electrode, and is parallel to the extending direction of the first electrode and the second electrode, the first device further comprises a third electrode set including a fifth electrode and a sixth electrode arranged at intervals and rotatable about the rotation axis by the rotating part, and electric field coupling occurs between the third electrode set and the second electrode set provided in the second device, a first straight line passing through the centers of the first electrode and the second electrode and a second straight line passing through the centers of the fifth electrode and the sixth electrode are perpendicular to each other, A power transmission system.

2. The power transmission system according to claim 1, wherein the first device further comprises a control unit that determines an angle of a rotational position of the first electrode, the second electrode, the fifth electrode, and the sixth electrode based on a power transmission efficiency of wireless power transmission by the electric field coupling, and controls the rotating part so that the rotational positions of the first electrode, the second electrode, the fifth electrode, and the sixth electrode are at the angle.

3. The power transmission system according to claim 2, wherein the control unit determines the angle of the rotational position to an angle at which the power transmission efficiency is the highest.

4. A first electrode set including a first electrode and a second electrode arranged at intervals, and capable of transmitting power by wireless power transmission by electric field coupling, The first electrode and the second electrode are provided with a rotating portion that enables rotation about a rotation axis that is not perpendicular to the first electrode and the second electrode. The rotation axis is perpendicular to a first straight line passing through the center of the first electrode and the center of the second electrode, and is parallel to the extending direction of the first electrode and the second electrode. The third electrode set further includes a fifth electrode and a sixth electrode that are arranged at an interval and are rotatable about the rotation axis by the rotating portion, and power transmission is possible by wireless power transmission by electric field coupling. A first straight line passing through the center of the first electrode and the center of the second electrode and a second straight line passing through the center of the fifth electrode and the center of the sixth electrode are perpendicular to each other. Power transmission device.

5. A first electrode set including a first electrode and a second electrode arranged at an interval, and capable of receiving power by wireless power transmission by electric field coupling. The first electrode and the second electrode are provided with a rotating portion that enables rotation about a rotation axis that is not perpendicular to the first electrode and the second electrode. The rotation axis is perpendicular to a first straight line passing through the center of the first electrode and the center of the second electrode, and is parallel to the extending direction of the first electrode and the second electrode. The third electrode set further includes a fifth electrode and a sixth electrode that are arranged at an interval and are rotatable about the rotation axis by the rotating portion, and capable of receiving power by wireless power transmission by electric field coupling. A first straight line passing through the center of the first electrode and the center of the second electrode and a second straight line passing through the center of the fifth electrode and the center of the sixth electrode are perpendicular to each other. Power receiving device.

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