JP2013172500A - Power transmission system, transmission equipment and power receiving apparatus - Google Patents

Abstract

A power transmission system, a power transmission device, and a power reception device capable of reducing a voltage applied to a resonance capacitor unit are provided.
A power transmission system 2 according to an embodiment includes a power transmission unit 17A including a power transmission coil unit 23A and a power transmission side resonance capacitor unit 25A, a power reception coil unit 23B, and a power reception side resonance capacitor unit 25B. Unit 17B. The power transmission core 31A and the power reception core 31B included in the power transmission coil unit and the power reception coil unit include a power transmission side base unit 35A and a power reception side base unit 35B around which the power transmission coil conductor 33A and the power reception coil conductor 33B are wound, a power transmission side base unit, and The power receiving side base portion is provided at both ends on the central axis C1 and C2 of the power transmission coil portion and the power receiving coil portion, respectively, and extends in a direction orthogonal to the central axis and the opposing direction of the power transmission coil portion and the power receiving coil portion. The power transmission side wide portion 37A and the power reception side wide portion 37B are wider than the width of the power transmission side base portion and the power reception side base portion.
[Selection] Figure 3

Description

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

  As a power transmission system, a system is known that uses electromagnetic induction to transmit power from a power transmission coil to a power reception coil in a contactless manner. In such a technique using electromagnetic induction, a resonance phenomenon is used by electrically connecting a resonance capacitor section for resonance to a power transmission coil and a power reception coil (see Non-Patent Document 1).

Shinji Noguchi, Yuichi Nagatsuka, Hiroyoshi Kaneko, Shigeru Abe, Tomio Yasuda, Akira Suzuki, “Long gap characteristics of small contactless power transformers for electric vehicles”, Proceedings of the Conference of the Institute of Electrical Engineers of Japan, 2010, 2010 , Page II II.259-II262

  When the resonance phenomenon is used in non-contact power transmission, power can be transmitted over a longer distance, while a large voltage tends to be applied to the resonant capacitor unit. In order to cope with a large voltage to be applied, it is conceivable that the resonant capacitor unit is composed of a plurality of capacitors. However, if the voltage applied to the resonant capacitor portion increases, the number of capacitors increases, and there is a concern that the configuration on the power transmission side and the configuration on the power reception side in the power transmission system may increase in size.

  Therefore, an object of the present invention is to provide a power transmission system, a power transmission device, and a power reception device that can reduce a voltage applied to a resonance capacitor unit.

  A power transmission system according to the present invention is a power transmission system that transmits power in a non-contact manner from a power transmission coil unit to a power reception coil unit that is arranged to face the power transmission coil unit, and a power transmission coil conductor is wound around a power transmission core. A power transmission unit including a power transmission coil unit, a power transmission side resonance capacitor unit serially connected to the power transmission coil unit, and a power reception coil unit in which a power reception coil conductor is wound around a power reception core, A power receiving unit including a power receiving coil unit extending in a first direction, the central axis of which is the extending direction of the central axis of the power transmitting coil unit, and a power receiving side resonance capacitor unit connected in series to the power receiving coil unit; Prepare. The power transmission core is a power transmission side base portion around which the power transmission coil conductor is wound, and a power transmission side wide portion provided at both ends of the power transmission side base portion in the first direction of the power transmission coil portion, A power transmission side wide portion extending in a second direction orthogonal to the direction and the opposing direction of the power transmission coil portion and the power reception coil portion, wherein the width in the second direction is wider than the width of the power transmission side base portion. Have. The power receiving core is a power receiving side base portion around which the power receiving coil conductor is wound, and a power receiving side wide portion provided at each of both ends of the power receiving coil portion in the first direction in the power receiving side base portion. A power receiving side wide portion having a width in the direction wider than that of the power receiving side base portion.

  In this configuration, for example, when an AC voltage is applied to the power transmission coil conductor of the power transmission coil unit, a magnetic field is generated by the current flowing through the power transmission coil conductor. Due to this magnetic field, an induced electromotive force is generated in the power receiving coil wound around the power receiving core. Therefore, power corresponding to the AC voltage supplied to the power transmission coil unit is transmitted from the power transmission coil unit to the power reception coil unit. The power transmission unit includes a power transmission side resonance capacitor unit connected in series to the power transmission coil unit, and the power reception unit includes a power reception side resonance capacitor unit connected in series to the power reception coil unit. This is power transmission using As a result, power can be transmitted over a longer distance. The power transmission core and the power reception core include a power transmission side wide portion and a power reception side wide portion at both ends of the power transmission side base portion and the power reception side base portion, respectively. When electric power is transmitted, magnetic flux is generated in the power transmission core and the power reception core, but the power transmission side wide portion and the power reception side wide portion function as a magnetic flux discharge port or suction port. As described above, since the magnetic flux discharge port and the suction port are wider and larger than the power transmission side base portion and the power reception side base portion, the coupling coefficient during power transmission increases. Thus, if the coupling coefficient increases, the voltage applied to the power transmission side resonance capacitor unit and the power reception side resonance capacitor unit can be reduced.

  The power transmission side wide portion protrudes outward from both sides of the power transmission side base portion in the second direction, and the power reception side wide portion protrudes outward from both sides of the power reception side base portion in the second direction. It may be.

  In this case, an allowable range of positional deviation between the power transmission coil unit and the power reception coil unit in the second direction is increased.

  The power transmission side wide part may be thicker on the power receiving coil part side than the power transmission side base part, and the power receiving side wide part may be thicker on the power transmission coil part side than the power receiving side base part.

  In this configuration, both end portions of the power transmission core and the power reception core in the first direction are bent in directions opposite to the power transmission core and the power reception core, respectively. As a result, when the magnetic flux is generated in the power transmission core and the power reception core, the direction of the magnetic flux tends to be directed in the opposite direction of the power transmission core and the power reception core, so that the coupling coefficient is likely to further increase.

  The other side surface of this invention concerns on the power transmission apparatus which transmits electric power to a receiving coil part non-contactingly. The power transmission device includes a power transmission coil unit in which a power transmission coil is wound around a power transmission core, and a power transmission side resonance capacitor unit that is connected in series with the power transmission coil unit. The power transmission core is a power transmission side base portion around which the power transmission coil conductor is wound, and a power transmission side wide portion provided at both ends of the power transmission side base portion on the central axis of the power transmission coil portion, and extending the central axis Extends in a second direction orthogonal to the opposing direction of the power transmission coil unit and the power reception coil unit, and the width of the second direction is wider than the width of the power transmission side base unit And a power transmission side wide portion.

  In this configuration, for example, when an AC voltage is applied to the power transmission coil conductor of the power transmission coil unit, a magnetic field is generated by the current flowing through the power transmission coil conductor. Due to this magnetic field, an induced electromotive force is generated in the power receiving coil portion. Therefore, the electric power corresponding to the alternating voltage supplied to the power transmission coil unit side is transmitted to the power reception coil unit side away from the power transmission coil unit. Since the power transmission device includes a power transmission resonance capacitor unit connected in series to the power transmission coil unit, the power transmission is power transmission using a resonance phenomenon. As a result, power can be transmitted over a longer distance. The power transmission core includes a power transmission side wide portion at both ends of the power transmission side base portion. When electric power is transmitted, magnetic flux is generated in the power transmission core, but the wide side on the power transmission side functions as a magnetic flux discharge port or suction port. As described above, since the magnetic flux release port or suction port is wider and larger than the power transmission side base portion, the coupling coefficient during power transmission increases. If the coupling coefficient increases, the voltage applied to the power transmission resonance capacitor unit can be reduced.

  Still another aspect of the present invention relates to a power receiving device that receives electric power transmitted in a non-contact manner from a power transmission coil unit. The power receiving device includes a power receiving coil unit in which a power receiving coil is wound around a power receiving core, and a power receiving side resonance capacitor unit that is connected in series to the power receiving coil unit. The power receiving core is a power receiving side base portion around which the power receiving coil conductor is wound, and a power receiving side wide portion provided at both ends of the power receiving side base portion on the central axis of the power receiving coil portion, and extending the central axis The first direction, which is a direction, and a second direction orthogonal to the opposing direction of the power transmission coil unit and the power reception coil unit, and the width of the second direction is wider than the width of the power receiving side base unit And a wide side portion.

  In this configuration, when a magnetic field is generated by supplying, for example, an AC voltage to the power transmission coil unit, an induced electromotive force is generated in the power receiving coil unit by the magnetic field. Therefore, the electric power corresponding to the alternating voltage supplied to the power transmission coil unit side is transmitted to the power reception coil unit side away from the power transmission coil unit. Since the power receiving device includes a power receiving side resonance capacitor unit connected in series to the power receiving coil unit, the power transmission is power transmission using a resonance phenomenon. As a result, power can be transmitted over a longer distance. The power receiving core includes power receiving side wide portions at both ends of the power receiving side base portion. When electric power is transmitted, magnetic flux is generated in the power receiving core, but the power receiving side wide portion functions as a magnetic flux release port or suction port. As described above, since the magnetic flux discharge port or suction port is wider and larger than the power receiving side base portion, the coupling coefficient during power transmission increases. If the coupling coefficient increases, it is possible to reduce the voltage applied to the power receiving side resonance capacitor unit.

  According to the present invention, the voltage applied to the resonant capacitor unit can be reduced.

It is drawing which shows schematic structure of the charging system to which the electric power transmission system which concerns on one Embodiment is applied. It is drawing which shows schematic structure of the electric power transmission system which concerns on one Embodiment. FIG. 3 is a perspective view of a power transmission coil unit and a power reception coil unit illustrated in FIG. 2. It is a perspective view which shows other embodiment of a power transmission coil part and a receiving coil part. It is a perspective view which shows the simulation model for a comparison. It is a graph which shows a simulation result.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description of the drawings, the same reference numerals are given to the same elements, and duplicate descriptions are omitted. The dimensional ratios in the drawings do not necessarily match those described. In the description, words indicating directions such as “up” and “down” are convenient words based on the state shown in the drawings.

  FIG. 1 is a diagram illustrating a schematic configuration of a charging system to which a power transmission system according to an embodiment is applied. The charging system 1 shown in FIG. 1 transmits power from a power transmission side system 11 installed on the ground to a power reception side system 13 mounted on a vehicle in a contactless manner, and charges a power storage device mounted on the vehicle. System.

  The power transmission side system 11 includes a power supply unit 15 that supplies power to be transmitted toward the power reception side system 13, and a power transmission unit 17 </ b> A that transmits power from the power supply unit 15 toward the power reception side system 13.

  The power supply unit 15 includes a DC power source 19 and an inverter unit 21. The power supply unit 15 converts the DC voltage from the DC power source 19 into an AC voltage by the inverter unit 21 and outputs the AC voltage to the power transmission unit (power transmission device) 17A. In the present embodiment, the power supply electrically connected to the inverter unit 21 is described as a DC power supply as described above, but is not limited to a DC power supply that supplies a DC voltage.

  The power transmission unit 17A includes a power transmission coil unit 23A and a resonance capacitor unit 25A that configures a series resonance circuit together with the power transmission coil unit 23A. The power transmission coil unit 23A, the resonant capacitor unit 25A, and the inverter unit 21 are connected in series.

  The power receiving side system 13 includes a power receiving unit 17 (power receiving device) B that receives power transmitted from the power transmitting unit 17A, and a drive battery 27 as a power storage device for storing the power received by the power receiving unit 17B. Since an AC voltage is output from the power receiving unit 17B, the drive battery 27 and the power receiving unit 17B are electrically connected via a rectifier 29 that converts the AC voltage from the power receiving unit 17B into a DC voltage.

  The power reception unit 17B includes a power reception coil unit 23B and a resonance capacitor unit 25B that constitutes a series resonance circuit together with the power reception coil unit 23B. The power receiving coil unit 23B is installed in the vehicle so as to be positioned on the power transmission coil unit 23A when power is transmitted, that is, when the vehicle is parked at a place where the power transmission side system 11 is installed. Since the configuration of the resonant capacitor unit 25B is the same as the configuration of the resonant capacitor unit 25A, description thereof is omitted. The power receiving coil unit 23B, the resonant capacitor unit 25B, and the rectifier 29 are connected in series.

  In the charging system 1, the inverter unit 21 converts the DC voltage from the DC power source 19 into an AC voltage having a predetermined frequency and supplies the AC voltage to the power transmission unit 17A. When an AC voltage is applied to the power transmission coil unit 23A of the power transmission unit 17A, an alternating current flows through the power transmission coil unit 23A, so that a magnetic field is generated. Due to the generated magnetic field, an induced electromotive force is generated in the receiving coil unit 23B. In this way, since the induced electromotive force is generated in the power receiving unit 17B by supplying power to the power transmitting unit 17A, power is transmitted from the power transmitting unit 17A to the power receiving unit 17B. Since the power transmission unit 17A and the power reception unit 17B each form a series resonance circuit, the power transmission occurs at a resonance frequency. As a result, power is efficiently transmitted. In addition, power can be transmitted over a longer distance by utilizing the resonance phenomenon.

  An AC voltage as an induced electromotive force generated in the power receiving unit 17B is converted into a DC voltage by the rectifier 29 and stored in the drive battery 27.

  In the charging system 1, power is transmitted in a non-contact manner using electromagnetic induction to the power receiving unit 17B that is separated from the power transmitting unit 17A by a certain distance. Therefore, the power transmitting unit 17A and the power receiving unit 17B are connected to each other. 2 is constituted.

  The power transmission unit 17A and the power reception unit 17B included in the power transmission system 2 will be further described with reference to FIGS. FIG. 2 is a side view illustrating a schematic configuration of the power transmission system according to the embodiment. In FIG. 2, the inverter part 21 and the rectifier 29 are shown for convenience. FIG. 3 is a perspective view of an example of the power transmission coil unit and the power reception coil unit. 2 and 3 show an arrangement relationship between the power transmission coil unit 23A and the power reception coil unit 23B during power transmission.

  The power transmission coil unit 23A and the power reception coil unit 23B are arranged apart from each other so that the extending directions of the central axes C1 and C2 are parallel to each other. For the sake of explanation, the facing direction of the power transmission coil unit 23A and the power reception coil unit 23B, that is, the direction from the power transmission coil unit 23A to the power reception coil unit 23B or the direction from the power reception coil unit 23B to the power transmission coil unit 23A is also referred to as z direction. . A direction orthogonal to the z direction, and the extending direction of the central axes C1 and C2 of the power transmission coil unit 23A and the power reception coil unit 23B is also referred to as an x direction (first direction), and is a direction orthogonal to the x direction and the z direction. Is also referred to as the y direction (second direction).

  The power transmission coil unit 23A is a coil with a core in which a power transmission coil conductor 33A is wound around a power transmission core 31A.

  One end of the power transmission coil conductor 33A is electrically connected to the resonance capacitor unit 25A, and the other end of the resonance capacitor unit 25A is electrically connected to one terminal of the inverter unit 21. The other end of the power transmission coil conductor 33A is electrically connected to the other terminal of the inverter unit 21.

  The number of turns of the power transmission coil conductor 33A and the capacity of the resonance capacitor unit 25A may be set so that a predetermined resonance frequency is obtained in the series resonance circuit constituted by the power transmission coil conductor 33A and the resonance capacitor unit 25A. The resonant capacitor unit 25A has a plurality of capacitors in order to obtain a predetermined capacity. In one embodiment, the resonant capacitor unit 25A may have a configuration in which a plurality of series-connected capacitor groups are connected in parallel to each other.

  Similarly, the receiving coil part 23B is a coil with a core in which a receiving coil conductor 33B is wound around a receiving core 31B. One end of the receiving coil conductor 33B is electrically connected to one end of the resonant capacitor unit 25B, and the other end of the resonant capacitor unit 25B is electrically connected to one terminal of the rectifier 29. The other end of the power receiving coil conductor 33B is electrically connected to the other terminal of the rectifier 29.

  The number of turns of the receiving coil conductor 33B and the capacity of the resonant capacitor unit 25B are the same as the number of turns of the power transmitting coil conductor 33A and the capacity of the resonant capacitor unit 25A. Since the configuration of the resonant capacitor unit 25B is the same as the configuration of the resonant capacitor unit 25A, the description thereof is omitted.

  Next, the configuration of the power transmission core 31A and the power reception core 31B will be described.

  The power transmission core 31A includes a plate-like base portion (power transmission side base portion) 35A and a pair of wide portions (power transmission side wide portions) 37A and 37A respectively disposed at both ends of the base portion 35A. When the power transmission core 31A is viewed from the thickness direction of the power transmission core 31A (z direction in FIGS. 2 and 3), the power transmission core 31A has an H shape. The base portion 35A and the wide portion 37A are magnetic bodies made of a magnetic material. The material of the base portion 35A and the wide portion 37A, which are magnetic materials, may be any material that is used as a so-called iron core. However, an example of the material of the base portion 35A and the wide portion 37A is ferrite.

  The planar view shape of the base body portion 35A (the shape when the power transmission core 31A is viewed from the z direction) is rectangular as shown in FIG. However, the planar view shape of the base portion 35A may be a square shape. The base portion 35A is a portion around which the power transmission coil conductor 33A is wound in the power transmission core 31A. The power transmission coil conductor 33A is spirally wound around the base portion 35A. The central axis of this spiral is the central axis C1 of the power transmission coil portion 23A.

  The wide portions 37A are disposed at both ends of the base portion 35A. The wide portion 37A extends in the y direction. In the y direction, the width W1 of the wide portion 37A is wider than the width W2 of the base portion 35A. The wide portion 37A protrudes from both sides of the base portion 35A in the y direction. The thickness t1 of the base portion 35A and the thickness t2 of the wide portion 37A are the same. The length of the wide portion 37A in the direction of the central axis C1 is sufficiently shorter than the corresponding length of the base portion 35A.

  The power transmission core 31A including the base portion 35A and the wide portions 37A provided at both ends thereof can be manufactured by separately manufacturing the base portion 35A and the wide portions 37A and then assembling them. The power transmission core 31A may be manufactured by integrally molding the base portion 35A and the wide portion 37A.

  An example of the length L1 of the power transmission coil portion 23A in the central axis C1 direction is 300 mm, an example of the width W2 of the base portion 35A is 110 mm, an example of the width W1 of the wide portion 37A is 200 mm, and the width portion 37A An example of the length in the direction of the central axis C1 is 20 mm. An example of the thickness t1 of the base portion 35A and the thickness t2 of the wide portion 37A is 10 mm.

  Although the specific value was given and demonstrated about the magnitude | size of the power transmission coil part 23A, the magnitude | size of the power transmission coil part 23A is not limited to the numerical value illustrated above.

  The power receiving core 31B includes a plate-shaped base portion 35B and a pair of wide portions 37B and 37B disposed at both ends of the power receiving coil conductor 33B. The power receiving core 31B is arranged away from the power transmission core 31A. The distance L2 between the power transmission core 31A and the power reception core 31B may be within a range in which power transmission using electromagnetic induction is possible, and is, for example, 12 cm. A passive coil conductor 33B is spirally wound around the base portion 35B. The center axis of this spiral corresponds to the center axis C2 of the passive coil portion 23B. In the arrangement at the time of power transmission as shown in FIGS. 2 and 3, since the central axes C1 and C2 are parallel, the extending direction of the central axis C2 of the passive coil conductor 33B is the same as the extending direction of the central axis C1. Is wound around the passive base portion 33B.

  The configurations of the base portion 35B and the wide portion 37B are the same as the configurations of the base portion 35A and the wide portion 37A of the power transmission coil portion 23A, and thus description thereof is omitted. The thickness of the base portion 35B and the wide portion 37B is the same as in the case of the base portion 35A and the wide portion 37A. Therefore, in FIG. 3, the distance L2 is represented by the distance between the wide portion 37A and the wide portion 37B, but the distance L2 corresponds to the distance between the base portion 35A and the base portion 35B.

  In the above configuration, when the AC voltage supplied from the inverter unit 21 is applied to the power transmission coil conductor 33A, a magnetic field is generated by the power transmission coil unit 23A. This magnetic field fluctuates according to voltage fluctuations in the alternating voltage. In a magnetic field in a certain state, a part of the magnetic flux is emitted from the wide portion 37A (the wide portion 37A on the right side in FIG. 2) of the pair of wide portions 37A of the power transmission core 31A, as indicated by arrows in FIG. Suction is performed from the wide portion 37B of the power receiving core 31B located on the wide portion 37A. Then, a part of the magnetic flux passing through the power receiving core 31B is released from a wide portion 37B (the wide portion 37B on the left side in FIG. 2) of the pair of wide portions 37B, which is different from the wide portion 37B on the magnetic flux suction side, The air is sucked from the wide portion 37A of the power transmission core 31A located below the wide portion 37B. Depending on the state of the magnetic field, the release and suction functions of the pair of wide portions 37A in the power transmission core 31A are reversed. Similarly, the release and suction functions of the pair of wide portions 37A in the power receiving core 31B are reversed.

  As described above, in the power transmission core 31A and the power reception core 31B, the wide portions 37A and 37B can be magnetic flux discharge ports or suction ports. Since the wide portions 37A and 37B having the magnetic flux releasing function or the sucking function are wider than the width W2 of the base portion 35A, more magnetic flux is easily released or sucked than when the wide portions 37A and 37B are not provided. As a result, the coupling coefficient increases in power transmission using electromagnetic induction from the power transmission coil unit 23A to the power reception coil unit 23B.

  The power transmission efficiency depends on the product (= kQ) of the coupling coefficient k and the Q (Q value) of the power transmission coil unit 17A, and increases as the product of the coupling coefficient k and the Q value increases. The voltage applied to both ends of the resonance capacitor unit 25A is Q times the voltage applied to the resistance of the resonance circuit composed of the power transmission coil unit 17A and the resonance capacitor unit 25A. In the configuration of the power transmission coil unit 23, since the coupling coefficient k can be increased as described above, Q = ωL / R (ω is the resonance frequency, L is the self-inductance of the power transmission coil unit 17A, and R is the resistance of the resonance circuit. For example, the Q value can be lowered by lowering the resonance frequency ω. Therefore, it is possible to reduce the voltage applied to both ends of the resonant capacitor unit 25A while maintaining or increasing the power transmission efficiency. Here, the power transmission side, that is, the power transmission coil unit 17A and the resonance capacitor unit 25A has been described, but the same applies to the power reception side, that is, the power reception coil unit 17B and the resonance capacitor unit 25B.

  Furthermore, since the power receiving unit 17B is mounted on an automobile, it is desired to be lightweight. Normally, since the power transmission unit 17A and the power reception unit 17B have the same configuration, it is also desired to reduce the weight of the power transmission unit 17A. In the power transmission core 31A and the power reception core 31B shown in FIGS. 2 and 3, the width W2 of the base portions 35A and 35B is not increased as the width W1 of the wide portions 37A and 37B, but the power transmission core 31A and the power reception core 31B. By making the shape of the planar view of the shape H, the coupling coefficient is improved as described above, and the weight can be reduced.

  Furthermore, in the y direction, the power transmission coil unit 23A and the power receiving coil unit 23B in the y direction are provided by including wide portions 37A and 37B that are wider than the base units 35A and 35B and project on both sides of the base units 35A and 35B. The allowable range of misalignment is widened. In other words, even if a positional deviation occurs between the power transmission coil unit 23A and the power reception coil unit 23B in the y direction, it is possible to reduce a decrease in the coupling coefficient. Normally, in the power transmission unit 17A and the power reception unit 17B, the resonance capacitors 25A and 25B have the maximum coupling coefficient when the power reception coil unit 23B is located immediately above the power transmission coil unit 23A, that is, the power transmission efficiency is maximum. Designed to be Therefore, in the y direction, it is possible to suppress a decrease in power transmission efficiency by reducing the influence of positional displacement between the power transmission coil unit 23A and the power reception coil unit 23B. As a result, the power transmission system 2 can transmit power with stable power transmission efficiency.

  In the automobile charging system 1, when the automobile is stopped at the place where the power transmission side system 11 is installed, the position in the front-rear direction is usually fixed by a car stop or the like. On the other hand, the left-right direction tends to fluctuate depending on the parking state. Therefore, by installing the power transmission unit 17A and the power reception unit 17B so that the x direction shown in FIG. 2 and FIG. The impact can be reduced.

  In the power transmission coil portion 23A shown in FIG. 2, the thicknesses t1 and t2 of the base portion 35A and the wide portion 37A are the same, but the thickness t2 of the wide portion 37A is thicker than the thickness t1 of the base portion 35A. May be. The same applies to the power receiving coil portion 23B.

  FIG. 4 is a perspective view showing an embodiment of the power transmission coil unit and the power reception coil unit when the width of the wide portion is larger than the thickness of the base body.

  The power transmission coil unit 39A has the same configuration as that of the power transmission coil unit 23A except that wide portions 43A are provided instead of the wide portions 37A at both ends of the base portion 35A of the power transmission core 41A. The thickness t2 of the wide portion 43A is thicker than the thickness t1 of the base portion 35A, and the wide portion 43A is thicker toward the power receiving coil portion 39B. In other words, the wide portion 43A extends from the base portion 35A toward the passive coil portion 39B in the z direction. In this configuration, a step is generated on the side facing the power receiving coil portion 39B in the base portion 35A and the wide portion 43A, while there is no step on the side opposite to the power receiving coil portion 39B side in the base portion 35A and the wide portion 43A. When the thickness t1 of the base portion 35A is 10 mm, an example of the thickness t2 of the wide portion 43A is 15 mm.

  The power receiving coil portion 39B has the same configuration as that of the power receiving coil portion 23B except that wide portions 43B are provided instead of the wide portions 37B at both ends of the base portion 35B of the power receiving core 41B. The thickness t2 of the wide portion 43B is thicker than the thickness t1 of the base portion 35B, and the wide portion 43B is thicker toward the power transmission coil portion 39A. In other words, the wide portion 43B extends from the base portion 35B to the power transmission coil portion 39A side in the z direction, and both end portions of the passive core 41B located on the central axis C2 are bent toward the passive coil portion 39B side. Yes. In this configuration, the base portion 35B and the wide portion 43B have a step on the side facing the power transmission coil portion 39A, while the base portion 35B and the wide portion 43B have no step on the side opposite to the power transmission coil portion 39A. When the thickness t1 of the base portion 35B is 10 mm, an example of the thickness t2 of the wide portion 43B is 15 mm.

  The power transmission coil unit 39A and the power reception coil unit 38B illustrated in FIG. 4 can be applied to the power transmission unit 17A and the power reception unit 17B instead of the power transmission coil unit 23A and the power reception coil unit 23B.

  In the above configuration, both ends of the power transmission coil portion 39A on the central axis C1 are bent toward the power receiving coil portion 39B, and both ends of the power receiving coil portion 39B on the central axis C2 are bent toward the power transmission coil portion 39A. Yes. In this case, the magnetic path when the power transmission coil unit 39A and the power reception coil unit 39B are regarded as one magnetic circuit is bent in both directions at both ends in the x direction of the power transmission coil unit 39A and the power reception coil unit 39B. As a result, the magnetic flux is more easily released and sucked from the wide portion 43A of the power transmission coil portion 39A and the wide portion 43B of the power reception coil portion 39B. For this reason, the coupling coefficient between the power transmitting coil unit 39A and the power receiving coil unit 39B is further increased, and the voltage applied to the resonant capacitor units 25A and 25B tends to be reduced as compared with the configurations shown in FIGS. As the voltage applied to the resonant capacitor units 25A and 25B is reduced, the number of capacitors constituting the resonant capacitor units 25A and 25B can be reduced, which further contributes to the miniaturization of the power transmission unit 17A and the power reception unit 17B.

  Also in the case of the power transmission coil unit 39A and the power receiving coil unit 39B, the width W2 in the y direction of the wide portions 43A and 43B is wider than the width W1 in the y direction of the base portions 35A and 35B. This is the same as in the case of the embodiment shown in FIGS.

  When the distance between the base portions 35A and 35B is the same as that shown in FIGS. 2 and 3, the distance L3 between the wide portions 43A and 43B located on the same side is as shown in FIGS. It becomes smaller than the indicated distance L2. As a result, the coupling coefficient is further improved.

  Next, referring to the simulation result, the point that the coupling coefficient is improved by providing the power transmission coil unit and the power reception coil unit with the wide part will be specifically shown.

  The simulation was performed for the configuration of the power transmission coil unit 23A and the power reception coil unit 23B illustrated in FIGS. 2 and 3 and the configuration of the power transmission coil unit 39A and the power reception coil unit 39B illustrated in FIG. For comparison, a simulation was also performed for the configuration of the power transmission coil unit 45A and the power reception coil unit 45B shown in FIG.

  The configuration of the power transmission coil unit 45A and the power reception coil unit 45B shown in FIG. 5 is such that the power transmission core 47A and the power reception core 47B are in the y direction instead of the wide portions 37A and 37B at both ends in the x direction of the base portions 35A and 35B, respectively. The configuration is the same as that of the power transmission coil unit 23A and the power reception coil unit 23B shown in FIGS. 2 and 3 except that the edge portions 49A and 49B having the same width as the base portions 35A and 35B are provided. The configurations of the power transmission coil unit 45A and the power reception coil unit 45B illustrated in FIG. 5 are obtained by deleting the regions protruding from the base units 35A and 35B in the wide portions 37A and 37B in the configuration of the power transmission coil unit 23A and the power reception coil unit 23B. Corresponds to the configuration. In FIG. 5, the thickness of the base portion 35A and the edge portion 49A is the same as in the case of the base portion 35A and the wide portion 37A. The same applies to the base portion 35B and the edge portion 49B. Therefore, also in FIG. 5, the distance L2 between the edge 45A and the edge 45B corresponds to the distance between the base portions 35A and 35B in the power transmission core 47A and the power reception core 47B.

  The simulation for the combination of the power transmission coil unit 45A and the power reception coil unit 45B shown in FIG. 5 is called simulation 1, and the simulation for the combination of the power transmission coil unit 23A and the power reception coil unit 23B shown in FIGS. The simulation for the set of the power transmission coil unit 39A and the power reception coil unit 39B shown in FIG.

  In simulations 1, 2, and 3, the distance between the base portion 35A and the base portion 35B (the distance between the opposing surfaces) L2 is 12 cm, and the distance between the power transmission coil conductor 33A and the power reception coil conductor 33B is 12 cm. 11 cm.

  The thicknesses t1 of the base portions 35A and 35B in the simulations 1, 2, and 3 are 10 mm. The thickness of the edge portions 47A and 47B in the simulation 1 and the thickness of the wide portions 37A and 37B in the simulation 2 are 10 mm like the base portions 35A and 35B. The thickness of the wide portions 43A and 43B in the simulation 3 is 15 mm.

  Furthermore, in simulations 1, 2, and 3, the width W2 in the y direction of the base portions 35A and 35B is 110 mm. In simulations 2 and 3, the width W1 in the y direction of the wide portions 37A, 37B, 43A, and 43B is 200 mm. In simulations 1, 2, and 3, the length L1 in the x direction of each of the power transmission coil portions 23A, 39A, and 45A and the power reception coil portions 23B, 39B, and 45B is 300 mm.

  Furthermore, in simulations 1, 2, and 3, the number of turns of the power transmission coil conductor 33A and the power reception coil conductor 33B was 47, and the coil resistance was 0.1Ω.

  In simulations 1, 2, and 3, the LC resonant circuit was configured using the same resonant capacitor, and the coupling coefficient was calculated under the same conditions except for the differences in the configuration of the power transmission core and the power reception core described above. .

  When there is no positional deviation in the y direction in the combination of the power transmission coil unit and the power receiving coil unit in each of simulations 1, 2, and 3, the coupling coefficient is 100 mm when the positional deviation in the y direction is 50 mm. For each case, it was calculated. The calculation results are as shown in the chart of FIG. FIG. 6 also shows the rate of change of the coupling coefficient when a positional deviation occurs. The rate of change is a value obtained by dividing the difference between the coupling coefficient when the deviation amount is 0 and the coupling coefficient of each deviation amount by the coupling coefficient when the deviation amount is 0, expressed as a percentage.

  In the chart of FIG. 6, comparing simulation 1 with simulations 2 and 3, it is understood that the coupling coefficient is improved by providing wide portions 37A and 37B and wide portions 43A and 43B even when there is no deviation. obtain. Furthermore, by providing the wide portions 37A and 37B and the wide portions 43A and 43B, it is possible to reduce the decrease in the coupling coefficient due to the displacement in the y direction. In addition, when comparing simulations 2 and 3, the coupling coefficient when there is no deviation is improved by making the wide part thick, and the reduction of the coupling coefficient when deviation occurs also makes the wide part thick. It can be understood that this can be reduced.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the invention. For example, in the power transmission coil portion 23A, the wide portion 37A protrudes on both sides of the base portion 35A in the y direction, but only one side may protrude. The same applies to the power receiving coil portion 23B. Even in this case, by providing the wide portions 37A and 37B larger than the base portions 35A and 35B, the magnetic flux release region or the suction region becomes large, so that the coupling coefficient is improved.

  Although the power transmission core 31A and the power reception core 31B have been described as plate-shaped, for example, they may be rod-shaped.

  The modified examples described for the power transmission coil unit 23A and the power reception coil unit 23B can be similarly applied to the power transmission coil unit 39A and the power reception coil unit 39B.

  Furthermore, in the said embodiment, although the charging system 1 of the motor vehicle was illustrated, a power transmission system is not limited to application to the charging system 1 of a motor vehicle, For example, the charging system in vehicles other than a mobile telephone, an electric toothbrush, and a motor vehicle 1 can also be applied. In addition, the power transmission system is not limited to the charging system 1 because it can be applied to a system that transmits power in a contactless manner.

  2 ... Power transmission system, 17A ... Power transmission unit, 17B ... Power reception unit, 23A ... Power transmission coil unit, 23B ... Power reception coil unit, 25A ... Resonance capacitor unit (power transmission side resonance capacitor unit), 25B ... Resonance capacitor unit (power reception side resonance) Capacitor part), 31A ... Power transmission core, 31B ... Power reception core, 33A ... Power transmission coil conductor, 33B ... Power reception coil conductor, 35A ... Base part (power transmission side base part), 35B ... Base part (power reception side base part), 37A ... Wide part (power transmission side wide part), 37B ... wide part (power reception side wide part), 39A ... power transmission coil part, 39B ... power reception coil part, 41A ... power transmission core, 41B ... power reception core, 43A ... wide part (power transmission side wide part) Part), 43B ... wide part (power receiving side wide part), C1 ... center axis (center axis of power transmission coil part), C2 ... center axis (center axis of power reception coil part), W1 ... width (sending) The width of the side wide portion and the power receiving side wide portions), W2 ... width (transmission side base portion and the width of the power-receiving-side base portion).

Claims (5)

A power transmission system that transmits power in a non-contact manner from the power transmission coil unit to a power reception coil unit that is disposed to face the power transmission coil unit,
A power transmission unit including the power transmission coil section in which a power transmission coil conductor is wound around a power transmission core, and a power transmission side resonance capacitor section connected in series to the power transmission coil section;
A power receiving coil portion in which a power receiving coil conductor is wound around a power receiving core, wherein a central axis of the power receiving coil portion extends in a first direction that is an extending direction of the central axis of the power transmitting coil portion. A power receiving unit including a power receiving coil unit and a power receiving side resonance capacitor unit connected in series to the power receiving coil unit;
With
The power transmission core is
A power transmission side base body around which the power transmission coil conductor is wound;
A power transmission side wide portion provided at each of both ends of the power transmission coil unit in the first direction in the power transmission side base unit, wherein the first direction is opposed to the power transmission coil unit and the power receiving coil unit. Extending in a second direction perpendicular to the direction, the power transmission side wide portion having a width in the second direction wider than the width of the power transmission side base body,
Have
The power receiving core is
A power receiving side base portion around which the power receiving coil conductor is wound;
A power receiving side wide portion provided at each of both ends of the power receiving coil portion in the first direction in the power receiving side base portion, wherein the power receiving side base portion has a width in the second direction wider than the width of the power receiving side base portion. Wide side,
Having
A power transmission system characterized by that. The power transmission side wide portion protrudes outward from both sides of the power transmission side base portion in the second direction,
The power receiving side wide part protrudes outward from both sides of the power receiving side base part in the second direction.
The power transmission system according to claim 1. The power transmission side wide part is thicker on the power receiving coil part side than the power transmission side base part,
The power receiving side wide part is thicker on the power transmission coil part side than the power receiving side base part.
The power transmission system according to claim 1 or 2. A power transmission device that transmits power in a contactless manner to a power receiving coil unit,
A power transmission coil unit disposed opposite to the power reception coil unit, and a power transmission coil wound around a power transmission core,
A power transmission side resonance capacitor unit connected in series to the power transmission coil unit;
With
The power transmission core is
A power transmission side base body around which the power transmission coil conductor is wound;
A power transmission side wide portion provided at each of both ends on the central axis of the power transmission coil portion in the power transmission side base portion, the first direction being the direction in which the central axis extends, and the power transmission coil portion, A power transmission side wide portion extending in a second direction orthogonal to the facing direction of the power receiving coil portion, the width of the second direction being wider than the width of the power transmission side base portion;
Having
A power transmission device characterized by that. A power receiving device that receives power transmitted in a non-contact manner from a power transmission coil unit,
The power receiving coil unit is disposed opposite to the power transmitting coil unit, and the power receiving coil is wound around the power receiving core.
A power receiving side resonance capacitor unit connected in series to the power receiving coil unit;
With
The power receiving core is
A power receiving side base portion around which the power receiving coil conductor is wound;
A power receiving side wide portion provided at each end of the power receiving coil portion on the central axis of the power receiving side base portion, the first direction being the direction in which the central axis extends; and the power transmitting coil portion; A power receiving side wide portion extending in a second direction orthogonal to the facing direction of the power receiving coil portion, the width of the second direction being wider than the width of the power receiving base portion;
Having
A power receiving device.

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