JP6387945B2 - Non-contact power transmission device and non-contact power reception device - Google Patents

Description

  The present invention relates to a non-contact power transmission device and a non-contact power reception device, and more particularly to a non-contact power transmission device and a non-contact power reception device having a plurality of capacitors.

  There is known a non-contact power transmission system that performs non-contact power transmission from a power transmission device to a power reception device (see Patent Documents 1 to 6). In the non-contact power transmission system, for example, non-contact power transmission is realized by utilizing a resonance phenomenon between a capacitor and a coil. Japanese Patent Laying-Open No. 2015-138842 (Patent Document 1) discloses a capacitor module used in a power transmission device and a power reception device. In this capacitor module, a plurality of series capacitors configured by connecting a plurality of capacitors in series are connected in parallel (see Patent Document 1).

JP2015-138842A JP2013-154815A JP2013-146154A JP2013-146148A JP 2013-110822 A JP 2013-126327 A

  When the capacitor module is formed by a plurality of capacitors as in Patent Document 1, it is conceivable to adjust the capacitance of the capacitor module by combining a plurality of types of capacitors having different capacitances. For example, it is conceivable to produce a capacitor module (capacitor array) having a desired capacitance by connecting a plurality (for example, three or more) of various series capacitors having different capacitances in parallel.

  However, in a capacitor array in which at least three series capacitors are connected in parallel, when series capacitors having a large capacitance are concentrated inside (for example, the central portion), heat generation inside the capacitor array increases. This is because the larger the capacitance, the lower the impedance of the series capacitor, and a larger current flows. Since the inner side of the capacitor array has lower heat dissipation than the outer side, when the heat generation on the inner side is larger than that on the outer side, the bias of the heat generation density (heat generation amount per unit area in unit time) in the capacitor array increases.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a non-contact power transmission device that can suppress a deviation in heat generation density that occurs in the capacitor array during power transmission. .

  Another object of the present invention is to provide a non-contact power receiving apparatus that can suppress a deviation in heat generation density that occurs in a capacitor array during power reception.

  A contactless power transmission device according to an aspect of the present invention includes a capacitor array and a power transmission coil. The capacitor array is formed by connecting in parallel at least three series capacitors each formed by connecting a plurality of capacitors in series. The power transmission coil transmits power in a non-contact manner to the power receiving coil of the power receiving device by causing a resonance phenomenon with the capacitor array. The plurality of series capacitors includes a first series capacitor and a second series capacitor having a larger capacitance than the first series capacitor. The second series capacitor is arranged outside the first series capacitor in the capacitor array.

  A contactless power receiving device according to another aspect of the present invention includes a capacitor array and a power receiving coil. The capacitor array is formed by connecting in parallel at least three series capacitors each formed by connecting a plurality of capacitors in series. The power reception coil receives power from the power transmission coil of the power transmission device in a non-contact manner by causing a resonance phenomenon with the capacitor array. The plurality of series capacitors includes a first series capacitor and a second series capacitor having a larger capacitance than the first series capacitor. The second series capacitor is arranged outside the first series capacitor in the capacitor array.

  Therefore, in these non-contact power transmission devices and non-contact power reception devices, the outer side of the capacitor array generates more heat than the inner side. Since the outer side of the capacitor array has higher heat dissipation than the inner side, the heat density generated in the capacitor array is biased compared to the case where the second series capacitor having a large capacitance is arranged inside the capacitor array. Is suppressed.

  According to the present invention, it is possible to provide a non-contact power transmission device that can suppress a deviation in heat generation density that occurs in the capacitor array during power transmission.

  In addition, according to the present invention, it is possible to provide a non-contact power receiving device that can suppress a deviation in heat generation density that occurs in the capacitor array during power reception.

It is a schematic block diagram of a non-contact power transmission system. It is a perspective view of the state where the cover of the power transmission device was opened. It is a figure which shows arrangement | positioning of the capacitor | condenser in a capacitor | condenser array. It is a reference figure for demonstrating the example of the capacitor | condenser array with a large bias | inclination of heat generation density. It is a figure which shows the electrostatic capacitance of each series capacitor | condenser contained in a capacitor | condenser array. It is a perspective view of the state where the cover of a power receiving device was opened. It is a figure which shows the electrostatic capacitance of each series capacitor | condenser contained in a capacitor | condenser array.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[Embodiment 1]
FIG. 1 is a schematic configuration diagram of a contactless power transmission system to which a contactless power transmission device according to Embodiment 1 of the present invention is applied. In the figure, an arrow D indicates a downward vertical direction, and an arrow U indicates an upward vertical direction. These are the same in FIGS.

  Referring to FIG. 1, contactless power transmission system 1 includes a vehicle 100, a power transmission device 20, and an AC power supply 200. The vehicle 100 includes a power receiving device 10, and the power receiving device 10 includes a power receiving unit 11 having a power receiving coil (not shown). The power transmission device 20 includes a power transmission unit 21 having a power transmission coil (not described) and a frequency converter 22. The power transmission unit 21 and the frequency converter 22 will be described in detail later.

  The power reception unit 11 is configured to receive power from the power transmission unit 21 in a contactless manner. In vehicle 100, the power received by power receiving unit 11 is supplied to a power storage device (not shown). Vehicle 100 can travel by generating travel driving force from the power of the power storage device. AC power supply 200 is, for example, a system power supply.

  The power transmission coil of the power transmission unit 21 forms a magnetic field by receiving supply of AC power from the AC power source 200, and transmits power to the power reception coil of the power reception unit 11 in a non-contact manner through the formed magnetic field. The number of turns of the conducting wire in the power transmission coil is appropriately designed so that the distance between the power transmission coil and the power reception coil, the Q value (for example, Q ≧ 100), and the coupling coefficient κ are increased.

  FIG. 2 is a perspective view of a state where the cover of the power transmission device 20 is opened. Referring to FIG. 2, frequency converter 22 receives supply of AC power from AC power supply 200, and converts the frequency of AC power into a desired frequency. The power transmission unit 21 transmits the AC power supplied from the frequency converter 22 to the power receiving device 10 in a contactless manner. The frequency converter 22 is connected to the power transmission unit 21 through wiring.

  The power transmission unit 21 includes a capacitor array 24, a power transmission coil 26, and a ferrite 28. The capacitor array 24 has a plurality of capacitors. More specifically, the capacitor array 24 is a capacitor module in which a plurality of series capacitors are connected in parallel. A series capacitor is a plurality of capacitors connected in series. The capacitor array 24 is disposed below the ferrite 28. The capacitor array 24 will be described in detail later.

  The power transmission coil 26 and the capacitor array 24 are connected to the frequency converter 22 through wiring. The power transmission coil 26 causes a resonance phenomenon with the capacitor array 24 to transmit power to the power reception coil of the power reception device 10 in a non-contact manner. The power transmission coil 26 is wound around the ferrite 28. The ferrite 28 functions as a core.

  FIG. 3 is a diagram showing the arrangement of capacitors in the capacitor array 24. Referring to FIG. 3, the capacitor array 24 is configured by connecting series capacitors 30, 40, 50, 60 and 70 in parallel. The series capacitor 30 is configured by connecting five capacitors 32 in series. Each of the series capacitors 40, 50, 60, and 70 is configured by connecting five capacitors in series, like the series capacitor 30.

  When a capacitor module is formed by a plurality of capacitors as in the capacitor array 24, it is conceivable to adjust the capacitance of the capacitor module by combining a plurality of types of capacitors having different capacitances. For example, it is conceivable to create a capacitor array having a desired capacitance by connecting a plurality (for example, three or more) of various series capacitors having different capacitances in parallel.

  However, in a capacitor array in which at least three series capacitors are connected in parallel, when series capacitors having a large capacitance are concentrated inside (for example, the central portion), heat generation inside the capacitor array increases. This is because the larger the capacitance, the lower the impedance of the series capacitor, and a larger current flows. Since the inside of the capacitor array has lower heat dissipation than the outside, when the heat generation on the inside is larger than that on the outside, the deviation of the heat generation density in the capacitor array becomes large.

  FIG. 4 is a reference diagram for explaining an example of a capacitor array having a large deviation in heat generation density. Referring to FIG. 4, capacitor array 500 is configured by connecting series capacitors 510, 520, 530, 540, and 550 in parallel. In this example, it is assumed that there are three types of capacitances of series capacitors, large, medium, and small. The capacitances of the series capacitors 510, 520, 530, 540, and 550 are assumed to be medium, medium, large, large, and small, respectively.

  In this case, the series capacitor 530 having a large capacitance is arranged in the center portion of the capacitor array 500. Further, the series capacitor 540 having a large capacitance is arranged adjacent to the series capacitor 530 (inside the capacitor array 500). Since the central portion of the capacitor array 500 has low heat dissipation compared to the end (outside), the heat generated by the series capacitors 530 and 540 is difficult to dissipate. On the other hand, the series capacitor 510 having a medium capacitance and the series capacitor 550 having a small capacitance are arranged at the end of the capacitor array 500. Since the end portion of the capacitor array 500 has high heat dissipation, the heat generated by the series capacitors 510 and 550 is easily radiated. That is, in the capacitor array 500, the heat dissipation performance of the portion where heat generation is large is low, and the heat dissipation performance of the portion where heat generation is not large is high. As a result, in the capacitor array 500, the bias of the heat generation density becomes large.

  In order to suppress the bias of the heat generation density, in the capacitor array 24 provided in the power transmission device 20 according to the first embodiment, the series capacitor having a large capacitance is disposed outside the series capacitor having a small capacitance.

  FIG. 5 is a diagram illustrating the capacitance of each series capacitor included in the capacitor array 24. Referring to FIG. 5, in the capacitor array 24, the capacitances of the series capacitors 30, 40, 50, 60, and 70 are large, medium, small, medium, and large, respectively. That is, the series capacitors 30 and 70 having a large capacitance are arranged outside the series capacitor 40, 50 and 60 having a smaller capacitance than the series capacitors 30 and 70 in the capacitor array 24. In other words, a series capacitor having a larger capacitance is arranged on the outer side in the capacitor array 24.

  Therefore, in the power transmission device 20, the outer side of the capacitor array 24 generates more heat than the inner side (center portion). Since the outer side of the capacitor array 24 has higher heat dissipation than the inner side (center portion), it generates heat as compared with a case where a series capacitor having a large capacitance is arranged on the inner side (center portion) of the capacitor array 24. Density of density is suppressed.

  In the first embodiment, an example is shown in which capacitors are arranged in 5 rows and 5 columns as the capacitor array 24, but the arrangement of the capacitors is not limited to this. For example, an arrangement such as 5 rows and 10 columns or 10 rows and 3 columns may be used.

[Embodiment 2]
In the first embodiment, in the capacitor array 24 included in the power transmission device 20, the series capacitor having a large capacitance is arranged outside the series capacitor having a small capacitance. In the second embodiment, in the capacitor array included in the power receiving device 10A, the series capacitor having a large capacitance is arranged outside the series capacitor having a small capacitance. Note that a series capacitor having a large capacitance may be arranged outside a series capacitor having a small capacitance in either one of the capacitor arrays of the power transmission device and the power receiving device. The series capacitor having a large capacitance may be arranged outside the series capacitor having a small capacitance.

  FIG. 6 is a perspective view of a state where the cover of the power receiving device 10A is opened. Referring to FIG. 6, power reception device 10A includes power reception unit 11A. For example, the power reception unit 11A receives power from the power transmission unit 21 (FIG. 1) of the power transmission device 20 in a non-contact manner.

  Power receiving unit 11 </ b> A includes a capacitor array 80, a power receiving coil 90, and a ferrite 95. The capacitor array 80 has a plurality of capacitors. More specifically, the capacitor array 80 is a capacitor module in which a plurality of series capacitors are connected in parallel. The capacitor array 80 is disposed above the ferrite 95.

  The power reception coil 90 receives power from the power transmission coil of the power transmission device 20 in a non-contact manner by causing a resonance phenomenon with the capacitor array 80. The power receiving coil 90 is wound around the ferrite 95. The ferrite 95 functions as a core.

  FIG. 7 is a diagram illustrating the capacitance of each series capacitor included in the capacitor array 80. Referring to FIG. 7, capacitor array 80 includes series capacitors 81, 82, 83, 84, 85. The capacitances of the series capacitors 81, 82, 83, 84, 85 are large, medium, small, medium, and large, respectively. That is, the series capacitors 81 and 85 having a large capacitance are arranged outside the series capacitors 82, 83 and 84 having a smaller capacitance than the series capacitors 81 and 85 in the capacitor array 80. In other words, a series capacitor having a larger capacitance is arranged on the outer side in the capacitor array 80.

  Therefore, in the power receiving device 10A, the outer side of the capacitor array 80 generates more heat than the inner side (center portion). Therefore, as compared with a case where a series capacitor having a large electrostatic capacitance is arranged inside (center part) of the capacitor array 80, a deviation in heat generation density is suppressed.

  In the second embodiment, an example is shown in which capacitors are arranged in 5 rows and 5 columns as the capacitor array 80, but the arrangement of the capacitors is not limited to this. For example, an arrangement such as 5 rows and 10 columns or 10 rows and 3 columns may be used.

  Further, in the first and second embodiments, in the capacitor arrays 24 and 80, the series capacitors having larger electrostatic capacities are arranged outside the capacitor arrays 24 and 80. However, the arrangement of the series capacitors in the capacitor array is not limited to this. For example, in a capacitor array in which five rows of series capacitors are connected in parallel, the respective capacitances are medium, small, large, large, and medium from the series capacitor at one end to the series capacitor at the other end ( Hereinafter, this will be referred to as “arrangement example 1”. In the arrangement example 1, since the series capacitor having a large capacitance is arranged in the central portion, it can be said that the deviation of the heat generation density in the capacitor array is relatively large.

  However, compared to the cases where the respective capacitances are small, medium, large, large, and medium (hereinafter referred to as “arrangement example 2”), the deviation of the heat generation density in the capacitor array is greater in arrangement example 1. small. In the arrangement example 2, a series capacitor having a larger capacitance is arranged inside the capacitor array, whereas in the arrangement example 1, a series capacitor in the capacitance is partially a series having a smaller capacitance. This is because it is arranged outside the capacitor. In other words, it is not always necessary to place a series capacitor having a larger capacitance outside the capacitor array, and even if a part of the series capacitor has a larger capacitance than a series capacitor having a smaller capacitance, it is not necessary. By disposing it outside, the deviation of the heat generation density is reduced.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Non-contact electric power transmission system 10,10A power receiving apparatus, 11,11A power receiving part, 20 Power transmission apparatus, 21 Power transmission part, 22 Frequency converter, 24,80,500 Capacitor array, 26 Power transmission coil, 28,95 Ferrite, 30 , 40, 50, 60, 70, 81, 82, 83, 84, 85, 510, 520, 530, 540, 550 Series capacitor, 32, 42, 52, 62, 72 capacitor, 90 power receiving coil, 100 vehicle, 200 AC source.

Claims (2)

A capacitor array in which at least three series capacitors each constituted by connecting a plurality of capacitors in series are connected in parallel;
A power transmission coil that transmits power in a non-contact manner to the power receiving coil of the power receiving device by generating a resonance phenomenon with the capacitor array;
The plurality of series capacitors include a first series capacitor and a second series capacitor having a larger capacitance than the first series capacitor;
The non-contact power transmission device, wherein the second series capacitor is disposed outside the first series capacitor in the capacitor array. A capacitor array in which at least three series capacitors each constituted by connecting a plurality of capacitors in series are connected in parallel;
A power receiving coil that receives power from the power transmitting coil of the power transmitting device in a non-contact manner by generating a resonance phenomenon with the capacitor array;
The plurality of series capacitors include a first series capacitor and a second series capacitor having a larger capacitance than the first series capacitor;
The non-contact power receiving device, wherein the second series capacitor is disposed outside the first series capacitor in the capacitor array.

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