Wireless power transmission system, and method for controlling wireless power transmission system

Abstract

To suppress fluctuation in receiving voltage of a power reception antenna.SOLUTION: A wireless power transmission system has: a plurality of power transmission antennae arranged adjacent to each other; a plurality of power transmission circuits for flowing current to the respective plurality of power transmission antennae; and a power reception antenna that faces at least one of the plurality of power transmission antennae and moves over the plurality of power transmission antennae. Adjacent power transmission antennae among the plurality of power transmission antennae are arranged so that at least some of respective end portions overlap each other, or the respective end portions approach each other. A phase difference between currents flowing through adjacent power transmission antennae among the plurality of power transmission antennae differs corresponding to a distance between the adjacent power transmission antennae.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a wireless power transmission system and a control method for the wireless power transmission system. [Background technology]

[0002] In recent years, the development of in-motion power transfer systems has progressed toward the practical application of electric vehicles (EVs) and automated guided vehicles (AGVs). In-motion power transfer systems, power is transmitted wirelessly from a power transmitting antenna to a power receiving antenna mounted on an EV or AGV passing above it.

[0003] In such systems, the power transmission antenna needs to be positioned to match the distance traveled by the EV or AGV, but manufacturing a long power transmission antenna is difficult, so the distance can sometimes be increased by arranging multiple power transmission antennas side by side.

[0004] However, even if power transmitting antennas are arranged at equal distances, their ends may overlap or may be arranged close to each other at different distances. In such cases, if the power transmitting antennas are driven synchronously, the magnetic fields at the ends may cancel or reinforce each other, making it difficult to obtain a stable receiving voltage when the power receiving antenna passes the end of the power transmitting antenna.

[0005] Non-patent document 1 describes a configuration in which, when the ends of power transmitting antennas overlap, a stable receiving voltage is obtained by driving the power transmitting antennas by passing currents that are 90 degrees out of phase between adjacent power transmitting antennas. [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] "Fundamental Study of a Non-Contact Power Transmission Pad Aimed at Application to Consumer Devices" Proceedings of the Tohoku Branch Joint Conference of Institutes of Electrical Engineers, 2007 Summary of the Invention [Problem to be solved by the invention]

[0007] In a wireless power transfer system for vehicles in motion, when a power receiving antenna moves over multiple power transmitting antennas and the power receiving antenna approaches a position between the power transmitting antennas, the received voltage fluctuates. Furthermore, as the distance between the power transmitting antennas changes, the amount of fluctuation in the received voltage also changes.

[0008] In the configuration described in Non-Patent Document 1, there are cases where fluctuations in the power receiving voltage cannot be suppressed completely depending on the distance between the power transmitting antennas.

[0009] An object of the present disclosure is to make it possible to suppress fluctuations in the power receiving voltage of a power receiving antenna. [Means for solving the problem]

[0010] The wireless power transmission system includes a plurality of transmitting antennas arranged adjacent to each other, a plurality of transmitting circuits that respectively pass current through the plurality of transmitting antennas, and a receiving antenna that faces at least one of the plurality of transmitting antennas and moves over the plurality of transmitting antennas, wherein adjacent ones of the plurality of transmitting antennas are arranged so that at least a portion of their ends overlap each other or so that their ends are close to each other, and the phase difference of the currents flowing through adjacent ones of the plurality of transmitting antennas differs depending on the distance between the adjacent ones of the plurality of transmitting antennas. [Effects of the Invention]

[0011] According to the present disclosure, fluctuations in the power receiving voltage of the power receiving antenna can be suppressed. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram illustrating a configuration example of a wireless power transmission system. [Figure 2] 10A and 10B are diagrams illustrating a specific configuration example of a power transmitting antenna. [Figure 3]FIG. 10 is a diagram illustrating a simulation result. [Figure 4] 10A and 10B are diagrams illustrating a specific configuration example of a power transmitting antenna. [Figure 5] FIG. 10 is a diagram illustrating a simulation result. [Figure 6] FIG. 10 is a diagram illustrating a simulation result. [Figure 7] FIG. 1 is a diagram illustrating a configuration example of a wireless power transmission system. [Figure 8] FIG. 1 is a diagram illustrating a configuration example of a wireless power transmission system. [Figure 9] FIG. 1 is a diagram illustrating a configuration example of a wireless power transmission system. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment will be described with reference to the drawings.

[0014] (First embodiment) 1 is a diagram showing an example of the configuration of a wireless power transmission system 10 according to the first embodiment. The wireless power transmission system 10 includes a power transmitting unit 100 and a power receiving unit 110.

[0015] The power transmitting unit 100 includes power transmitting antennas 101a and 101b, power transmitting circuits 102a and 102b, a power source 103, and a control device 104. The power receiving unit 110 includes a power receiving antenna 111, a power receiving circuit 112, and a load 113.

[0016] In this embodiment, there are two pairs of power transmitting antennas 101a, 101b and power transmitting circuits 102a, 102b, and one pair of power receiving antenna 111 and power receiving circuit 112, but this is not limiting. There may be three or more pairs of power transmitting antennas and power transmitting circuits, and two or more pairs of power receiving antennas and power receiving circuits.

[0017] The power transmitting antennas 101a and 101b and the power receiving antenna 111 are each shaped like a coil made of a wound conductor. As shown in Fig. 2, the power transmitting antennas 101a and 101b are each elongated in one direction and are arranged side by side along that direction. The multiple power transmitting antennas 101a and 101b are arranged adjacent to each other in a straight line.

[0018] The power receiving antenna 111 moves parallel to the long direction of the power transmitting antennas 101a and 101b while maintaining a certain distance from the power transmitting antennas 101a and 101b. The power receiving antenna 111 faces at least one of the multiple power transmitting antennas 101a and 101b and moves above the multiple power transmitting antennas 101a and 101b.

[0019] The power transmitting circuits 102a and 102b are each configured with a known switching circuit, convert DC power supplied from the power supply 103 into AC power at the frequency of the clock signal, and supply the AC power to the power transmitting antennas 101a and 101b. The multiple power transmitting circuits 102a and 102b pass currents through the multiple power transmitting antennas 101a and 101b, respectively. This generates magnetic flux near the power transmitting antennas 101a and 101b.

[0020] The power receiving antenna 111 generates AC power using the magnetic flux generated by the power transmitting antennas 101a and 101b. The power receiving circuit 112 is configured with a known rectifier circuit, converts the AC power received by the power receiving antenna 111 into DC power, and supplies the DC power to the load 113.

[0021] The control device 104 is connected to the power transmitting circuits 102a and 102b and controls the phase difference of the switching of the currents flowing through the power transmitting antennas 101a and 101b. The phase difference of the switching controlled by the control device 104 varies depending on the distance between the ends of the power transmitting antennas 101a and 101b.

[0022] The number of pairs of power transmitting antennas and power transmitting circuits may be three or more. The control device 104 controls the phase difference between the currents flowing through adjacent power transmitting antennas among the plurality of power transmitting antennas for the plurality of power transmitting circuits.

[0023] Next, a description will be given of a control method for the wireless power transmission system 10. When the power transmitting antennas 101a and 101b are arranged side by side as in this embodiment, the power transmitting antennas 101a and 101b are coupled to each other near their adjacent ends.

[0024] If currents of the same phase are passed through the power transmitting antennas 101a and 101b, the magnetic fluxes generated near the adjacent ends will affect each other, resulting in an unstable power receiving voltage at the power receiving antenna 111. Therefore, by passing currents of different phases through the power transmitting antennas 101a and 101b, the magnetic fluxes near the adjacent ends will be adjusted so as not to affect each other, and the power receiving antenna 111 will be able to obtain a stable power receiving voltage.

[0025] At this time, the coupling between the power transmitting antennas 101a and 101b changes depending on the distance between the power transmitting antennas 101a and 101b, and therefore the optimal value of the phase difference between the currents flowing through the power transmitting antennas 101a and 101b also changes depending on the distance between the power transmitting antennas 101a and 101b.

[0026] 2 is a diagram showing a specific example of the configuration near the ends of the power transmitting antennas 101a and 101b according to this embodiment when the adjacent ends overlap. The conductor thickness at each of the adjacent ends of the power transmitting antennas 101a and 101b is thinner than the conductor thickness in the remaining portions. This keeps the distance between the power transmitting antennas 101a and 101b and the power receiving antenna 111 substantially constant even when the ends of the power transmitting antennas 101a and 101b overlap.

[0027] The number of pairs of power transmitting antennas and power transmitting circuits may be three or more. Adjacent power transmitting antennas among the multiple power transmitting antennas are arranged so that at least a portion of their ends overlap each other. The thickness of the overlapping ends of the power transmitting antennas is thinner than the thickness of the remaining portions of the power transmitting antennas. It is preferable that the length of the overlapping ends of the power transmitting antennas is 7% or less of the longitudinal length of the power transmitting antennas.

[0028] The multiple power transmitting antennas 101a and 101b have long sides substantially parallel to a first direction and are aligned along the first direction. The multiple power transmitting circuits 102a and 102b are connected to the multiple power transmitting antennas 101a and 101b, respectively, and pass current through the multiple power transmitting antennas 101a and 101b. The power receiving antenna 111 faces at least one of the multiple power transmitting antennas 101a, 101a, and 101b and moves parallel to the multiple power transmitting antennas 101a and 101b in the first direction. The short sides of the power transmitting antennas 101a, 101b and the power receiving antenna 111 are shorter than the long sides of the power transmitting antennas 101a and 101b.

[0029] 3 is a diagram showing the change in the receiving voltage with respect to the moving position of the power receiving antenna 111 when the adjacent ends of the power transmitting antennas 101a and 101b overlap by 35 mm. In this case, the length of the power transmitting antennas 101a and 101b is 1500 mm. The power receiving antenna 111 moves over the power transmitting antennas 101a and 101b as shown in FIG. 2. The power receiving antenna position is set to 0 mm when the power receiving antenna 111 reaches the center position of the power transmitting antennas 101a and 101b.

[0030] As shown in Figure 3, when currents of the same phase with a phase difference θ of 0 degrees are passed through adjacent transmitting antennas 101a and 101b, the receiving voltage at a receiving antenna position of approximately 0 mm is approximately 4 V higher than when the receiving antenna 111 is located at another location.

[0031] In contrast, it is shown that by passing a current with a phase difference θ greater than 0 degrees through the power transmitting antennas 101a and 101b, an increase in the power receiving voltage near the power receiving antenna position of 0 mm is suppressed.

[0032] When the current phase difference θ is 40 degrees, the power receiving voltage at a power receiving antenna position near 0 mm increases by only about 1 V compared to the power receiving voltage when the power receiving antenna 111 is located at another location.

[0033] 4 is a diagram showing a specific example of the configuration near the ends of the power transmitting antennas 101a and 101b when the adjacent ends of the power transmitting antennas 101a and 101b are spaced apart. Note that the thickness of the conductor at the adjacent ends of the power transmitting antennas 101a and 101b may be thinner than the other portions, as in the configuration example of FIG.

[0034] The number of pairs of power transmitting antennas and power transmitting circuits may be three or more. Adjacent power transmitting antennas among the multiple power transmitting antennas are arranged so that their ends are close to each other. The distance between the ends of adjacent power transmitting antennas is preferably 0.5% or less of the longitudinal length of the power transmitting antenna.

[0035] In addition, when there are three or more pairs of power transmitting antennas and power transmitting circuits, adjacent power transmitting antennas among the multiple power transmitting antennas may be arranged so that at least a portion of their ends overlap each other, and may be arranged so that their ends are close to each other.

[0036] Fig. 5 is a diagram showing the change in the receiving voltage with respect to the movement position of the power receiving antenna 111 when the adjacent ends of the power transmitting antennas 101a and 101b are spaced 1 mm apart as in Fig. 4. In this case, the length of the power transmitting antennas 101a and 101b is 1500 mm. The power receiving antenna position is set to 0 mm when the power receiving antenna 111 is at the center position between the power transmitting antennas 101a and 101b.

[0037] As shown in Figure 5, when adjacent transmitting antennas 101a and 101b are supplied with currents of the same phase with a phase difference θ of 0 degrees, the receiving voltage at a receiving antenna position of approximately 0 mm is approximately 1 V higher than when the receiving antenna 111 is located at another location.

[0038] In contrast, it is shown that by passing a current with a phase difference θ greater than 0 degrees through the power transmitting antennas 101a and 101b, an increase in the power receiving voltage near the power receiving antenna position of 0 mm is suppressed.

[0039] When the current phase difference θ is 20 degrees, the power receiving voltage at a power receiving antenna position near 0 mm shows almost no increase compared to the power receiving voltage when the power receiving antenna 111 is located at another location.

[0040] 6 is a diagram showing the relationship between the distance between the power transmitting antennas 101a and 101b and the optimal phase difference θ of the currents flowing through the adjacent power transmitting antennas 101a and 101b. In this case, the power transmitting antennas 101a and 101b have a length of 1500 mm. The power receiving antenna 111 has a length of 600 mm. The distance at which the power transmitting antennas 101a and 101b overlap is considered positive, and the distance at which the power transmitting antennas 101a and 101b are separated is considered negative.

[0041] Figure 6 shows that when the overlapping distance between the transmitting antennas 101a and 101b is large, the optimal phase difference θ changes little, and when the separation distance between the transmitting antennas 101a and 101b is large, it is difficult to stabilize the receiving voltage with the phase difference θ.

[0042] When the power transmitting antennas 101a and 101b overlap by 100 mm or more, the coupling between the power transmitting antennas 101a and 101b becomes large, and the stability of the receiving voltage becomes low even if the phase difference θ is larger than 0 degrees. When the power transmitting antennas 101a and 101b are separated by 3 mm or more, the coupling between the power transmitting antennas 101a and 101b becomes small, and the stability of the receiving voltage does not improve even if the phase difference θ is larger than 0 degrees.

[0043] The number of pairs of power transmitting antennas and power transmitting circuits may be three or more. The phase difference between the currents flowing through adjacent power transmitting antennas among the multiple power transmitting antennas varies depending on the distance between the adjacent power transmitting antennas. It is preferable that the phase difference θ between the currents flowing through adjacent power transmitting antennas is 70 degrees or less.

[0044] Furthermore, the control device 104 is disposed at a position approximately equidistant from each of the multiple power transmitting circuits 102a and 102b. As described above, when the power transmitting antennas 101a and 101b are long in the traveling direction and the power transmitting circuits 102a and 102b and the control device 104 are smaller than the power transmitting antennas 101a and 101b, a propagation delay occurs between each of the power transmitting circuits 102a and 102b and the control device 104. When a propagation delay occurs, in order to obtain a stable receiving voltage, it becomes necessary to provide a phase difference θ that takes the propagation delay into account in addition to a phase difference according to the distance between the power transmitting antennas 101a and 101b.

[0045] By placing the control device 104 at a position approximately equidistant from each of the power transmitting circuits 102a and 102b and applying a current with a phase difference θ corresponding to the distance between the power transmitting antennas 101a and 101b, it is possible to obtain a stable receiving voltage.

[0046] As described above, by passing currents of different phases through the adjacent power transmitting antennas 101a and 101b, it is possible to suppress fluctuations in the received voltage when the power receiving antenna 111 moves to a position adjacent to the power transmitting antennas 101a and 101b. The appropriate phase difference θ of the currents changes depending on the distance between the power transmitting antennas 101a and 101b. This makes it possible to realize a wireless power transmission system 10 that can obtain a stable received voltage.

[0047] (Second embodiment) Fig. 7 is a diagram showing an example of the configuration of a wireless power transmission system 70 according to the second embodiment. In the wireless power transmission system 70 of Fig. 7 described below, the components already described in the wireless power transmission system 10 shown in Fig. 1 are denoted by the same reference numerals, and description thereof will be omitted.

[0048] The wireless power transmission system 70 includes a power transmitting unit 700 and a power receiving unit 110 .

[0049] The power transmitting unit 700 includes power transmitting antennas 101 a and 101 b, power transmitting circuits 102 a and 102 b, a power source 103 , a control device 104 , and a distance detection device 705 .

[0050] The distance detection device 705 is connected to the power transmitting antennas 101 a and 101 b, detects the distance between the adjacent ends of the power transmitting antennas 101 a and 101 b, and transmits the detected distance to the control device 104 .

[0051] The control device 104 determines the phase difference between the switching of the currents flowing through the power transmitting circuits 102a and 102b in accordance with the distance between the adjacent ends of the power transmitting antennas 101a and 101b transmitted from the distance detection device 705.

[0052] Here, an example of a distance detection method of the distance detection device 705 will be described. An applicable method is to install an LED at one end of each of the power transmitting antennas 101a and 101b, install a photodetector at the other end, and have the distance detection device 705 detect the distance between the ends of the power transmitting antennas 101a and 101b when the wireless power transmission system 70 is powered on.

[0053] By using this embodiment, even if the distance between the ends of the adjacent power transmitting antennas 101a and 101b changes due to aging or the like, it is possible to continue operating the wireless power transmission system 70 with a current having an appropriate phase difference θ. This makes it possible to realize a wireless power transmission system 70 that can obtain a stable receiving voltage.

[0054] In the present embodiment, there are two pairs of power transmitting antennas 101a and 101b and power transmitting circuits 102a and 102b, and one pair of power receiving antenna 111 and power receiving circuit 112. However, the present invention is not limited to this. There may be three or more pairs of power transmitting antennas and power transmitting circuits, and two or more pairs of power receiving antennas and power receiving circuits.

[0055] When there are multiple pairs of power transmitting antennas and power transmitting circuits, a distance detection device 705 is installed to detect the distance between the ends of each power transmitting antenna, and the phase of the current flowing through the power transmitting antenna is controlled according to the distance between the ends of each power transmitting antenna.

[0056] The distance detection device 705 detects the distance between adjacent power transmitting antennas among the multiple power transmitting antennas. The control device 104 controls the phase difference θ between the currents flowing through the adjacent power transmitting antennas based on the distance detected by the distance detection device 705.

[0057] (Third embodiment) Fig. 8 is a diagram showing an example of the configuration of a wireless power transmission system 80 according to the third embodiment. In the wireless power transmission system 80 of Fig. 8 described below, the components already described in the wireless power transmission system 10 shown in Fig. 1 are denoted by the same reference numerals, and description thereof will be omitted.

[0058] The wireless power transmission system 80 includes a power transmitting unit 100 and a power receiving unit 810. The power receiving unit 810 includes a power receiving antenna 111, a power receiving circuit 112, a load 113, and a power receiving voltage detection device 814.

[0059] The receiving voltage detection device 814 is connected to the power receiving circuit 112 and detects the receiving voltage output to the load 113. The receiving voltage detection device 814 is connected to the control device 104 and transmits the receiving voltage of the load 113 to the control device 104. The receiving voltage detection device 814 and the control device 104 are connected to each other wirelessly or by wire.

[0060] The control device 104 controls the power transmitting antennas 101a and 101b via the power transmitting circuits 102a and 102b so that currents having a phase difference θ flow through them. At this time, the receiving voltage detection device 814 transmits the detected receiving voltage to the control device 104. The control device 104 controls the phase difference θ of the currents flowing through the power transmitting antennas 101a and 101b based on the stability of the transmitted receiving voltage.

[0061] By using this embodiment, it is possible to continuously operate the wireless power transmission system 80 with a current having an appropriate phase difference θ, regardless of the distance between the ends of the adjacent power transmitting antennas 101a and 101b. This makes it possible to realize a wireless power transmission system 80 that can obtain a stable receiving voltage.

[0062] In the present embodiment, the case has been described where there are two pairs of power transmitting antennas 101a and 101b and power transmitting circuits 102a and 102b, and one pair of power receiving antenna 111 and power receiving circuit 112, but this is not limiting. There may be three or more pairs of power transmitting antennas and power transmitting circuits, and two or more pairs of power receiving antennas and power receiving circuits. When there are two or more pairs of power receiving antennas and power receiving circuits, each pair of power receiving antennas and power receiving circuits has a power receiving voltage detection device 814, and transmits the power receiving voltage at each load to the control device 104.

[0063] The power receiving voltage detection device 814 detects the power receiving voltage of the power receiving antenna 111. The control device 104 controls the phase difference θ between the currents flowing through the adjacent power transmitting antennas based on the stability of the power receiving voltage detected by the power receiving voltage detection device 814.

[0064] (Fourth embodiment) Fig. 9 is a diagram illustrating an example of the configuration of a wireless power transmission system 90 according to the fourth embodiment. In the wireless power transmission system 90 of Fig. 9 described below, the components already described in the wireless power transmission system 10 shown in Fig. 1 are denoted by the same reference numerals, and description thereof will be omitted.

[0065] The wireless power transmission system 90 includes a power transmitting unit 900 and a power receiving unit 110. The power transmitting unit 900 includes power transmitting antennas 101a, 101b, 101c, and 101d, power transmitting circuits 102a, 102b, 102c, and 102d, a power source 103, and a control device 104.

[0066] The power transmitting antennas 101a, 101b, 101c, and 101d are each elongated in one direction and arranged in a circular pattern as shown in Fig. 9. The ends of the power transmitting antennas 101a, 101b, 101c, and 101d are arranged so that they overlap or are close to each other. The multiple power transmitting antennas 101a, 101b, 101c, and 101d are arranged adjacent to each other in a circular pattern.

[0067] The power transmitting antenna 101b is adjacent to the power transmitting antenna 101a. The power transmitting antenna 101c is adjacent to the power transmitting antenna 101b. The power transmitting antenna 101d is adjacent to the power transmitting antenna 101c. The power transmitting antenna 101a is adjacent to the power transmitting antenna 101d.

[0068] The power transmitting circuits 102 a , 102 b , 102 c , and 102 d are connected to the respective power transmitting antennas 101 a , 101 b , 101 c , and 101 d , a power source 103 , and a control device 104 .

[0069] The control device 104 controls the phase difference θ of the switching of the currents flowing through the power transmitting antennas 101a, 101b, 101c, and 101d. The phase difference of the switching controlled by the control device 104 varies depending on the distance between the ends of the power transmitting antennas 101a, 101b, 101c, and 101d.

[0070] When the receiving antenna 111 starts moving from a state facing the transmitting antenna 101a, the control device 104 determines the phase difference of the current output from the transmitting circuit 102b connected to the adjacent transmitting antenna 101b based on the phase of the current output from the transmitting circuit 102a.

[0071] Similarly, when the receiving antenna 111 starts moving from a state facing the transmitting antenna 101b, the control device 104 determines the phase difference of the current output from the transmitting circuit 102c connected to the adjacent transmitting antenna 101c based on the phase of the current output from the transmitting circuit 102b.

[0072] Similarly, when the receiving antenna 111 starts moving from a state facing the transmitting antenna 101c, the control device 104 determines the phase difference of the current output from the transmitting circuit 102d connected to the adjacent transmitting antenna 101d based on the phase of the current output from the transmitting circuit 102c.

[0073] Similarly, when the receiving antenna 111 starts moving from a state facing the transmitting antenna 101d, the control device 104 determines the phase difference of the current output from the transmitting circuit 102a connected to the adjacent transmitting antenna 101a based on the phase of the current output from the transmitting circuit 102d.

[0074] The current flowing through the power transmitting antenna 101b has a positive phase difference with respect to the phase of the current flowing through the power transmitting antenna 101a. In this case, the current flowing through the power transmitting antenna 101c has a negative phase difference with respect to the phase of the current flowing through the power transmitting antenna 101b. At this time, the current flowing through the power transmitting antenna 101d has a positive phase difference with respect to the phase of the current flowing through the power transmitting antenna 101c. At this time, the current flowing through the power transmitting antenna 101a has a negative phase difference with respect to the phase of the current flowing through the power transmitting antenna 101d.

[0075] If the phase differences of the currents output to the power transmitting antennas 101a to 101d are all positive values, the currents output will have large phase differences between the adjacent power transmitting antennas 101a and 101d. In this case, when the power receiving antenna 111 moves from above the power transmitting antenna 101d to above the power transmitting antenna 101a, stable power transmission becomes difficult.

[0076] As described above, by alternately applying a positive and negative phase difference to the currents flowing through adjacent power transmitting antennas, stable power transmission is possible even when the power transmitting antennas are arranged in a circle. This makes it possible to realize a wireless power transmission system 90 that can obtain a stable receiving voltage.

[0077] In this embodiment, four pairs of power transmitting antennas and power transmitting circuits and one pair of power receiving antennas and power receiving circuits have been described, but the present invention is not limited to this. There may be five or more pairs of power transmitting antennas and power transmitting circuits, and two or more pairs of power receiving antennas and power receiving circuits.

[0078] As described above, according to the first to fourth embodiments, the wireless power transmission system can suppress fluctuations in the receiving voltage and obtain a stable receiving voltage by controlling the phase difference of the currents flowing through the mutually opposing transmitting antennas according to the distance between the transmitting antennas.

[0079] The wireless power transmission system can also supply power to an electric vehicle (EV) or an automated guided vehicle (AGV) having the power receiving unit 110 while the vehicle is traveling. The wireless power transmission system can wirelessly transmit power from a power transmitting antenna to a power receiving antenna mounted on an EV or AGV passing above it.

[0080] It should be noted that the above-described embodiments merely illustrate specific examples of implementing the present disclosure, and the technical scope of the present disclosure should not be construed as being limited by these embodiments. In other words, the present disclosure can be implemented in various forms without departing from its technical concept or main features.

[0081] The disclosure of this embodiment includes the following configurations and methods. (Configuration 1) a plurality of power transmitting antennas arranged adjacent to each other; a plurality of power transmitting circuits that respectively supply current to the plurality of power transmitting antennas; a power receiving antenna that faces at least one of the plurality of power transmitting antennas and moves over the plurality of power transmitting antennas, Adjacent power transmitting antennas among the plurality of power transmitting antennas are arranged such that at least a portion of an end of each of the power transmitting antennas overlaps with or is adjacent to each other; A wireless power transmission system, characterized in that a phase difference between currents flowing through adjacent ones of the plurality of power transmitting antennas varies depending on the distance between the adjacent power transmitting antennas. (Configuration 2) The wireless power transmission system according to configuration 1, further comprising a control unit that controls a phase difference between currents flowing through adjacent ones of the plurality of power transmitting antennas for the plurality of power transmitting circuits. (Configuration 3) 3. The wireless power transmission system according to configuration 2, wherein the control unit is disposed at approximately equal distances from each of the plurality of power transmission circuits. (Configuration 4) a distance detection unit that detects a distance between adjacent power transmitting antennas among the plurality of power transmitting antennas; The wireless power transmission system according to configuration 2 or 3, wherein the control unit controls a phase difference between currents flowing through the adjacent power transmitting antennas based on the distance detected by the distance detection unit. (Configuration 5) a receiving voltage detection unit that detects a receiving voltage of the power receiving antenna; The wireless power transmission system according to configuration 2 or 3, wherein the control unit controls the phase difference between the currents flowing through the adjacent power transmitting antennas based on the received power voltage detected by the received power voltage detection unit. (Configuration 6) The wireless power transmission system according to configuration 5, wherein the control unit controls the phase difference between the currents flowing through the adjacent power transmitting antennas based on the stability of the receiving voltage detected by the receiving voltage detection unit. (Configuration 7) 7. The wireless power transmission system according to any one of configurations 1 to 6, wherein the plurality of power transmitting antennas are arranged linearly and adjacent to each other. (Configuration 8) 7. The wireless power transmission system according to any one of configurations 1 to 6, wherein the plurality of power transmitting antennas are arranged adjacent to each other in a ring shape. (Configuration 9) the plurality of power transmitting antennas include a first power transmitting antenna, a second power transmitting antenna, and a third power transmitting antenna; the second transmitting antenna is adjacent to the first transmitting antenna; the third transmitting antenna is adjacent to the second transmitting antenna; a current flowing through the second power transmitting antenna has a positive phase difference with respect to a current flowing through the first power transmitting antenna; 9. The wireless power transmission system according to configuration 8, wherein the current flowing through the third power transmitting antenna has a negative phase difference with respect to the current flowing through the third power transmitting antenna. (Configuration 10) the adjacent power transmitting antennas are arranged such that at least a portion of each end of each antenna overlaps with the other; 10. The wireless power transmission system according to any one of configurations 1 to 9, wherein the thickness of the overlapping ends of the power transmitting antennas is thinner than the thickness of the other portions of the power transmitting antennas. (Configuration 11) the adjacent power transmitting antennas are arranged such that at least a portion of each end of each antenna overlaps with the other; 11. The wireless power transmission system according to any one of configurations 1 to 10, wherein the length of the overlapping ends of the power transmitting antennas is 7% or less of the length of the power transmitting antennas in the longitudinal direction. (Configuration 12) the plurality of power transmitting antennas are arranged such that their ends are adjacent to each other; 10. The wireless power transmission system according to any one of configurations 1 to 9, wherein the distance between the ends of the adjacent power transmitting antennas is 0.5% or less of the length of the power transmitting antennas in the longitudinal direction. (Configuration 13) 13. The wireless power transmission system according to any one of configurations 1 to 12, wherein the phase difference between the currents flowing through the adjacent power transmitting antennas is 70 degrees or less. (Configuration 14) 14. The wireless power transmission system according to any one of configurations 1 to 13, wherein each of the plurality of power transmission circuits converts DC power into AC power. (Configuration 15) 15. The wireless power transmission system according to configuration 14, further comprising a power receiving circuit that converts AC power received by the power receiving antenna into DC power. (Method 1) a plurality of power transmitting antennas arranged adjacent to each other; a plurality of power transmitting circuits that respectively supply current to the plurality of power transmitting antennas; a power receiving antenna that faces at least one of the plurality of power transmitting antennas and moves over the plurality of power transmitting antennas, Adjacent power transmitting antennas among the plurality of power transmitting antennas are arranged such that at least a portion of an end of each of the power transmitting antennas overlaps with or is adjacent to each other; The control method for a wireless power transmission system is characterized in that it includes a step of controlling so that a phase difference between currents flowing through adjacent power transmitting antennas among the plurality of power transmitting antennas varies depending on the distance between the adjacent power transmitting antennas. [Explanation of symbols]

[0082] 10, 70, 80, 90 Wireless power transmission system; 100, 700, 900 Power transmitting device; 101a, 101b, 101c, 101d Power transmitting antenna; 102a, 102b, 102c, 102d Power transmitting circuit; 103 Power supply; 104 Control device; 110, 810 Power receiving device; 111 Power receiving antenna; 112 Power receiving circuit; 113 Load; 814 Power receiving voltage detection device

Claims

1. a plurality of power transmitting antennas arranged adjacent to each other; a plurality of power transmitting circuits that respectively supply current to the plurality of power transmitting antennas; a power receiving antenna that faces at least one of the plurality of power transmitting antennas and moves over the plurality of power transmitting antennas, Adjacent power transmitting antennas among the plurality of power transmitting antennas are arranged such that at least a portion of an end of each of the power transmitting antennas overlaps with or is adjacent to each other; A wireless power transmission system, characterized in that a phase difference between currents flowing through adjacent ones of the plurality of power transmitting antennas varies depending on the distance between the adjacent power transmitting antennas.

2. The wireless power transmission system according to claim 1 , further comprising a control unit that controls a phase difference between currents flowing through adjacent ones of the plurality of power transmitting antennas for the plurality of power transmitting circuits.

3. The wireless power transmission system according to claim 2 , wherein the control unit is disposed at approximately equal distances from each of the plurality of power transmission circuits.

4. a distance detection unit that detects a distance between adjacent power transmitting antennas among the plurality of power transmitting antennas; The wireless power transmission system according to claim 2 , wherein the control unit controls a phase difference between the currents flowing through the adjacent power transmitting antennas based on the distance detected by the distance detection unit.

5. a receiving voltage detection unit that detects a receiving voltage of the power receiving antenna; 3. The wireless power transmission system according to claim 2, wherein the control unit controls a phase difference between currents flowing through the adjacent power transmitting antennas based on the received power voltage detected by the received power voltage detection unit.

6. 6. The wireless power transmission system according to claim 5, wherein the control unit controls a phase difference between currents flowing through the adjacent power transmitting antennas based on the stability of the received voltage detected by the received voltage detection unit.

7. The wireless power transmission system according to claim 1 , wherein the plurality of power transmitting antennas are arranged adjacent to each other in a straight line.

8. The wireless power transmission system according to claim 1 , wherein the plurality of power transmitting antennas are arranged adjacent to each other in a circular shape.

9. the plurality of power transmitting antennas include a first power transmitting antenna, a second power transmitting antenna, and a third power transmitting antenna; the second transmitting antenna is adjacent to the first transmitting antenna; the third transmitting antenna is adjacent to the second transmitting antenna; a current flowing through the second power transmitting antenna has a positive phase difference with respect to a current flowing through the first power transmitting antenna; The wireless power transmission system according to claim 8 , wherein the current flowing through the third power transmitting antenna has a negative phase difference with respect to the current flowing through the third power transmitting antenna.

10. the adjacent power transmitting antennas are arranged such that at least a portion of each end of each antenna overlaps with the other; The wireless power transmission system according to claim 1 , wherein the thickness of the overlapping ends of the power transmitting antennas is thinner than the thickness of the remaining portions of the power transmitting antennas.

11. the adjacent power transmitting antennas are arranged such that at least a portion of each end of each antenna overlaps with the other; 2. The wireless power transmission system according to claim 1, wherein the length of the overlapping ends of the power transmitting antennas is 7% or less of the length of the power transmitting antennas in the longitudinal direction.

12. the plurality of power transmitting antennas are arranged such that their ends are adjacent to each other; 2. The wireless power transmission system according to claim 1, wherein the distance between the ends of the adjacent power transmitting antennas is 0.5% or less of the longitudinal length of the power transmitting antennas.

13. 2. The wireless power transmission system according to claim 1, wherein the phase difference between the currents flowing through the adjacent power transmitting antennas is 70 degrees or less.

14. The wireless power transmission system according to claim 1 , wherein each of the plurality of power transmission circuits converts DC power into AC power.

15. 15. The wireless power transmission system according to claim 14, further comprising a power receiving circuit that converts AC power received by the power receiving antenna into DC power.

16. a plurality of power transmitting antennas arranged adjacent to each other; a plurality of power transmitting circuits that respectively supply current to the plurality of power transmitting antennas; a power receiving antenna that faces at least one of the plurality of power transmitting antennas and moves over the plurality of power transmitting antennas, Adjacent power transmitting antennas among the plurality of power transmitting antennas are arranged such that at least a portion of an end of each of the power transmitting antennas overlaps with or is adjacent to each other; The control method for a wireless power transmission system is characterized in that it includes a step of controlling so that a phase difference between currents flowing through adjacent power transmitting antennas among the plurality of power transmitting antennas varies depending on the distance between the adjacent power transmitting antennas.

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