JP6587895B2 - Contactless power supply system - Google Patents

Description

  The present invention relates to a non-contact power feeding system, and more particularly to a non-contact power feeding system for a plug-in hybrid vehicle or an electric vehicle that performs non-contact power feeding between a power transmission coil installed on the ground and a power receiving coil installed on a lower surface of a vehicle body. It relates to a technique suitable for the above.

  For plug-in hybrid vehicles (PHEVs) and electric vehicles (EVs) that are charged with external power, wireless charging (non-contact charging) due to the troublesome work of connecting the charging cable, dirt on clothes, anxiety during rainy weather, etc. ) Needs are increasing.

  Non-contact power feeding includes an electromagnetic induction type that uses electromagnetic induction between a primary coil on the ground side and a secondary coil on the vehicle upper side, and a magnetic field resonance type that uses magnetic field resonance. Among them, the electromagnetic induction type has a very high power transmission efficiency, but has a feature that the primary coil and the secondary coil must be sufficiently close to each other. On the other hand, the magnetic field resonance type may have a certain distance between the primary coil and the secondary coil, but has a feature that the power transmission efficiency is lower than that of the electromagnetic induction type. Conventionally, there has been proposed an electromagnetic induction type non-contact power feeding device that suppresses the influence of leakage magnetic flux outside the vehicle body even if there is a positional deviation between the power feeding unit (primary coil) and the power receiving unit (secondary coil) (for example, , See Patent Document 1). Conventionally, there has been proposed a non-contact power feeding device that has a combination of a plurality of power transmission / reception coils and uses a coil that opposes according to the displacement of the vehicle (see, for example, Patent Document 2).

JP 2011-49230 A JP2015-19551A

  There are helical coils and spiral coils as the types of coils used in non-contact power supply systems, but it was decided to adopt spiral coils as primary and secondary coils in international standardization of non-contact power supply systems for automobiles. . Since the spiral coil is weaker in positional deviation (lateral deviation) than the helical coil, it is important to take measures against the positional deviation of the coil.

  In view of the above problems, an object of the present invention is to maintain good power transmission efficiency even when a positional deviation occurs between a primary coil and a secondary coil in a non-contact power feeding system for automobiles.

A non-contact power feeding system according to one aspect of the present invention is a non-contact power feeding system in which a power transmission coil installed on the ground and a power receiving coil installed on a lower surface of a vehicle body face each other and perform non-contact power feeding between the power transmitting coil and the power receiving coil. In the contact power supply system, the power transmission coil is configured by one spiral coil, the power reception coil is divided into a plurality of spiral coils, and the outer edge shape of the power transmission coil and the outer edge shape of the power reception coil are substantially the same. are the same, have a respective shape by the plurality of spiral coils were divided outer edge of the receiving coil into a plurality as outer edge, the plurality of spiral coils are spaced apart in the vehicle width direction to each other, said plurality of The plurality of coil cores on which the spiral coils are respectively placed are separated from each other in the vehicle width direction .

  According to this, since the power receiving coil is divided into a plurality of spiral coils, even if the power receiving coil is misaligned with respect to the power transmitting coil, the electromotive force generated in each spiral coil is added together to make the power receiving coil as a whole large. Electric power can be generated.

  Specifically, the plurality of spiral coils are two spiral coils obtained by dividing the outer edge shape of the power receiving coil into two equal parts in the vehicle width direction.

  According to this, it is possible to deal with a positional shift in the vehicle width direction.

  Specifically, the plurality of spiral coils are three spiral coils obtained by dividing the outer edge shape of the power receiving coil into three in the vehicle width direction.

  According to this, it is possible to cope with the details by the positional deviation in the vehicle width direction.

In the non-contact power feeding system according to another aspect of the present invention, the power transmission coil installed on the ground and the power receiving coil installed on the lower surface of the vehicle body face each other, and the non-contact power feeding is performed between the power transmission coil and the power receiving coil. The power transmission coil is configured by one spiral coil, the power reception coil is divided into a plurality of spiral coils, and the plurality of spiral coils are outer edges of the power reception coil. Each of the shapes divided into a plurality of shapes is used as an outer edge shape, and the plurality of spiral coils are three spiral coils obtained by dividing the outer edge shape of the power receiving coil into three in the vehicle width direction. The width in the vehicle width direction of the spiral coils at both ends is made equal to the allowable positional deviation between the power transmission coil and the power reception coil.

  According to this, it is possible to maintain good power transmission efficiency within an allowable range of misalignment between the power transmission coil and the power reception coil.

Further, in the non-contact power feeding system according to another aspect of the present invention, the power transmission coil installed on the ground and the power receiving coil installed on the lower surface of the vehicle body face each other and are not between the power transmitting coil and the power receiving coil. A contactless power supply system for performing contact power supply, wherein the power transmission coil is configured by one spiral coil, the power reception coil is divided into a plurality of spiral coils, and the plurality of spiral coils are the power reception coils. The outer edge shape is divided into a plurality of shapes as outer edge shapes, and the plurality of spiral coils are four spiral coils obtained by dividing the outer edge shape of the power receiving coil into four in the vehicle length direction and the vehicle width direction.

  According to this, it is possible to deal with a positional shift in the vehicle length direction and the vehicle width direction.

  The non-contact power supply system may include a plurality of rectifier circuits that rectify electromotive forces generated in the plurality of spiral coils, and outputs of the plurality of rectifier circuits may be connected in series or in parallel.

  According to the present invention, even if a positional deviation occurs between the power transmission coil (primary coil) and the power reception coil (secondary coil), the power transmission efficiency can be kept good.

Schematic of the non-contact electric power feeding system which concerns on one Embodiment of this invention Plan view and sectional view of power transmission coil according to an example Plan view and sectional view of power receiving coil (two-part) according to an example Electrical circuit diagram in which spiral coils divided into multiple parts are electrically connected in series Electrical circuit diagram in which spiral coils divided into multiple parts are electrically connected in parallel 3 is a bottom view of the vehicle body on which the power receiving coil of FIG. 3 is installed. The figure explaining magnetic flux in the case where there is no position shift with a power transmission coil and a power reception coil The graph which shows the relationship between the position shift of a power transmission coil and a power reception coil, and a coupling coefficient Bottom view of a vehicle body with a receiving coil (3 divisions) installed according to another example Furthermore, the bottom view of the vehicle body in which the power receiving coil (4 divisions) according to another example is installed

  Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed explanation than necessary may be omitted. For example, detailed descriptions of already well-known matters and repeated descriptions for substantially the same configuration may be omitted. This is to avoid the following description from becoming unnecessarily redundant and to facilitate understanding by those skilled in the art.

  The inventor (s) provides the accompanying drawings and the following description in order for those skilled in the art to fully understand the present invention, and these are intended to limit the subject matter described in the claims. Not what you want. In addition, the dimensions, thicknesses, detailed shapes of details, and the like of each member depicted in the drawings may be different from actual ones.

  FIG. 1 shows an outline of a non-contact power feeding system according to an embodiment of the present invention. For example, the non-contact power feeding system according to the present embodiment is a magnetic resonance type non-contact power feeding system that wirelessly charges a battery 30 of a vehicle 100 such as a plug-in hybrid vehicle or an electric vehicle.

  In the non-contact power feeding system according to the present embodiment, the ground device 200 and the power transmission unit 60 are installed on the ground. The automobile 100 and the ground device 200 can communicate with each other by the radio 300. The automobile 100 determines the amount of charge of the battery 30 and requests the ground device 200 to start / stop power supply appropriately through the radio 300. The ground device 200 controls supply / stop of electric energy to the vehicle 100 according to a request from the vehicle 100.

  When supplying electric energy to the automobile 100, the ground device 200 generates a 3 kW class high-frequency current in the 85 kHz band (81.38 k to 90 kHz) from commercial power (AC power supply). The high-frequency current generated by the ground device 200 is supplied to the power transmission unit 60 through the cable 201. A power transmission coil (primary coil) (not shown) is accommodated in the power transmission unit 60, and a strong magnetic field is generated in the power transmission unit 60 when a high-frequency current is passed through the power transmission coil.

  On the other hand, in the automobile 100, the power receiving unit 10 is installed on the lower surface of the vehicle body. When charging the battery 30, the automobile 100 is moved so that the power receiving unit 10 comes to a position facing the power transmission unit 60 in the vertical direction. The gap between the power reception unit 10 and the power transmission unit 60 is 100 to 160 mm.

  The power reception unit 10 accommodates a resonance circuit including a power reception coil (secondary coil) and a capacitor (not shown). The resonance circuit is resonated when the power reception coil is exposed to a magnetic field generated by the power transmission unit 60. A high frequency current is generated in the power receiving unit 10. The high frequency current generated in the power receiving unit 10 is converted into a direct current by the rectifier 20 and charged to the battery 30. Thus, in the system according to the present embodiment, electric energy is supplied wirelessly from the ground device 200 to the automobile 100 by magnetic field resonance.

  An inverter 40 is connected to the battery 30. When driving the automobile 100, the inverter 40 converts the direct current stored in the battery 30 into an alternating current and drives the electric motor 50 that is a power source of the automobile 100.

  FIG. 2 is a plan view and a cross-sectional view of a power transmission coil according to an example. A power transmission coil 61 is accommodated in the power transmission unit 60. The power transmission coil 61 is a spiral coil in which an insulating coated electric wire 62 having a diameter of 5.4 mm is wound in two rounds and eight times in a circular spiral shape, and has an outer diameter of 350 mm and an inner diameter of 260 mm. The power transmission coil 61 is mounted on a disk-shaped coil core 63 made of a magnetic material such as ferrite. The diameter of the coil core 63 is 400 mm.

  FIG. 3 is a plan view and a cross-sectional view of a power receiving coil (divided into two parts) according to an example. A power receiving coil 11 is accommodated in the power receiving unit 10. The power receiving coil 11 is divided into two semicircular spiral coils 11a and 11b so that the circular outer edge shape (diameter 350 mm) is divided into two equal parts. Each of the spiral coils 11a and 11b is a coil obtained by winding an insulating coated electric wire 12 having a diameter of 5.4 mm into a semicircular spiral 8 times in one stage, and has an outer radius of 175 mm and an inner radius of 130 mm. The spiral coils 11a and 11b are respectively mounted on semi-disc shaped coil cores 13a and 13b made of a magnetic material such as ferrite. The radius of the coil cores 13a and 13b is 200 mm.

  Note that the shape of the power receiving coil 11 is not necessarily the same as the shape of the power transmitting coil 61. For example, the outer diameter and inner diameter of the power receiving coil 11 may be made smaller by 100 mm than the above (outer diameter 250 mm, inner diameter 160 mm). By reducing the size of the power receiving coil 11 in this way, the cost of the power receiving unit 10 can be reduced, and the mounting operation of the power receiving unit 10 is facilitated.

  Further, neither the power transmission coil 61 nor the power reception coil 11 needs to be circular. For example, the power transmission coil 61 and / or the power reception coil 11 may be oval or oval long in the vehicle width direction.

FIG. 4 is an example of an electric circuit diagram in which spiral coils divided into a plurality are electrically connected in series. Resonance capacitors 14a and 14b are connected to the spiral coils 11a and 11b, respectively, to form an LC resonance circuit. These LC resonance circuits are connected to the rectifier circuits 15a and 15b, respectively. The rectifier circuits 15a and 15b respectively perform full-wave rectification on the high-frequency current generated in the LC resonance circuit and output a direct current. The positive output terminal of the rectifier circuit 15a is connected to one end of the reactor 16, the negative output terminal of the rectifier circuit 15a is connected to the positive output terminal of the rectifier circuit 1 5 b. The smoothing capacitor 17 is connected to the other end of the reactor 16 to the negative output terminal of the rectifier circuit 1 5 b.

FIG. 5 is an example of an electric circuit diagram in which spiral coils divided into a plurality are electrically connected in parallel. Resonance capacitors 14a and 14b are connected to the spiral coils 11a and 11b, respectively, to form an LC resonance circuit. These LC resonance circuits are connected to the rectifier circuits 15a and 15b, respectively. The rectifier circuits 15a and 15b respectively perform full-wave rectification on the high-frequency current generated in the LC resonance circuit and output a direct current. Positive output terminals of the rectifier circuits 15 a and 15 b are connected to one end of the reactor 16. The smoothing capacitor 17 is connected to the other end of the reactor 16 and the negative output terminals of the rectifier circuits 1 5 a and 15 b.

Thus, the spiral coils 11a, to the output of 11b is connected rectifier circuit 1 5 a, 1 5 b may be connected in series or may be connected in parallel.

  In addition, the reactor 16 is omissible in the electric circuit shown in FIG. 4 and FIG.

  FIG. 6 is a bottom view of the vehicle body on which the power receiving coil of FIG. 3 is installed. The power receiving unit 10 is installed between the left and right rear wheels at the rear of the vehicle, for example. The lower surface of the automobile 100 is covered with an under cover 101 made of iron or aluminum, and the power receiving coil 11 accommodated in the power receiving unit 10 is attached to the under cover 101. More specifically, the coil cores 13 a and 13 b to which the spiral coils 11 a and 11 b constituting the power receiving coil 11 are attached are attached to the under cover 101.

  What is important here is that the power receiving unit 10 is attached to the under cover 101 in such an orientation that the spiral coils 11a and 11b are positioned on the left and right in the vehicle width direction. That is, in a state in which the power receiving unit 10 is attached, the power receiving coil 11 includes two spiral coils 11a and 11b obtained by dividing the outer edge shape into two equal parts in the vehicle width direction.

  The reason why the spiral coils 11a and 11b are arranged on the left and right in the vehicle width direction is that when the automobile 100 is parked at a predetermined position for charging the battery, the position in the vehicle length direction can be regulated by a vehicle stop. This is because there is no such thing in the width direction, and the position in the vehicle width direction cannot be regulated, so that it is considered that the power receiving unit 10 is likely to be displaced in the vehicle width direction with respect to the power transmission unit 60.

  FIG. 7 is a diagram for explaining the magnetic flux when there is no positional deviation between the power transmission coil and the power reception coil. FIG. 3 is a plan view of the power transmission coil 61 and the power reception coil 11. For convenience, the power receiving coil 11 is drawn smaller than the power transmitting coil 61.

  When a high-frequency current is applied to the power transmission coil 61, a magnetic field as indicated by the magnetic flux 70 is generated in the power transmission coil 61. When the magnetic flux 70 generated in the power transmission coil 61 is transmitted to the spiral coils 11a and 11b, a high-frequency current is generated in each of the spiral coils 11a and 11b by magnetic field resonance.

  When there is no position shift between the power transmission coil 61 and the power reception coil 11, the direction of the magnetic flux 70 transmitted to the spiral coils 11a and 11b constituting the power reception coil 11 is the same. On the other hand, when the position of the power receiving coil 11 is shifted and the spiral coil 11 a is inside the plan view of the power transmission coil 61 and the spiral coil 11 b is outside the plan view of the power transmission coil 61, it is transmitted to the spiral coils 11 a and 11 b constituting the power receiving coil 11. The directions of the magnetic flux 70 are opposite to each other.

  If the power receiving coil 11 is composed of one circular spiral coil, the magnetic flux 70 transmitted to the power receiving coil 11 cancels and weakens when the positional deviation between the power transmitting coil 61 and the power receiving coil 11 increases. The electromotive force generated in the battery is reduced. On the other hand, by dividing the power receiving coil 11 into a plurality of spiral coils (for example, the spiral coils 11a and 11b) as in the present embodiment, each spiral coil even if the positional deviation between the power transmitting coil 61 and the power receiving coil 11 increases. The electromotive forces are generated independently of each other. Therefore, by adding the electromotive forces generated in the spiral coils, a large amount of power can be generated as the entire power receiving coil 11.

  In the example of FIG. 7, the direction of the electromotive voltage generated in the spiral coil 11b is reversed depending on whether the power transmission coil 61 and the power receiving coil 11 are not misaligned. Need to switch connections. Therefore, as shown in FIGS. 4 and 5, both the spiral coils 11a and 11b are connected in series or in parallel after being rectified to direct current, so that each spiral coil can be connected regardless of the direction of the electromotive voltage generated in each spiral coil. The generated electromotive force can be added together.

  Next, the verification result of the power transmission efficiency in the non-contact power feeding system according to the present embodiment is shown. FIG. 8 is a graph showing the relationship between the positional deviation between the power transmission coil and the power reception coil and the coupling coefficient. Here, both the power transmission coil 61 and the power reception coil 11 have an outer diameter of 350 mm and an inner diameter of 260 mm. “Coil shift” refers to a shift between the centers of the power transmission coil 61 and the power reception coil 11, and the centers of the power transmission coil 61 and the power reception coil 11 are aligned (the state of “(a) no coil position shift” in FIG. 7). The coil deviation is 0 mm. On the other hand, the state of “(b) Coil position deviation” in FIG. 7 corresponds to a coil deviation of 120 mm.

  In both the conventional example in which the power receiving coil 11 is configured by one circular spiral coil and the present embodiment in which the power receiving coil 11 is divided into two spiral coils 11a and 11b, the coil deviation increases. The coupling coefficient between the power transmission coil 61 and the power reception coil 11 is reduced. However, since the coil deviation exceeds 70 mm, the present embodiment can maintain a higher coupling coefficient than the conventional example. That is, the effect of dividing the power receiving coil 11 into two spiral coils 11a and 11b appears.

  The number of divisions of the power receiving coil 11 may be three or more. By dividing the power receiving coil 11 into three or more spiral coils, it is possible to respond more precisely to the positional deviation between the power transmitting coil 61 and the power receiving coil 11.

  For example, when the power receiving coil 11 is shifted in the vehicle width direction with respect to the power transmitting coil 61, a part of the right end or the left end of the power receiving coil 11 comes out to the outside in plan view of the power transmitting coil 61 and most of the power receiving coil 11 is the power transmitting coil 61. It can be considered that it is inside the plan view. Therefore, the power receiving coil 11 may be divided into three in the vehicle width direction. FIG. 9 is a bottom view of a vehicle body provided with a power receiving coil (three-part division) according to another example. The power receiving coil 11 includes three spiral coils 11a, 11b, and 11c obtained by dividing the circular outer edge shape into three in the vehicle width direction. Here, the middle spiral coil 11c is made larger than the spiral coils 11a and 11b at both ends.

  In particular, it is preferable that the width in the vehicle width direction of the spiral coils 11a and 11b at both ends is matched with the allowable displacement (for example, 100 mm) between the power transmission coil 61 and the power reception coil 11. As a result, the power transmission efficiency can be kept good within the allowable range of displacement between the power transmission coil 61 and the power reception coil 11.

  Further, considering that the power receiving coil 11 is displaced in the vehicle length direction with respect to the power transmitting coil 61, the power receiving coil 11 may be divided into four in the vehicle length direction and the vehicle width direction. FIG. 10 is a bottom view of a vehicle body on which a power receiving coil (four divisions) according to another example is installed. The power receiving coil 11 has four spiral coils 11a, 11b, 11c, and 11d obtained by dividing the circular outer edge shape into four in the vehicle length direction and the vehicle width direction. The shape and size of each spiral coil are the same. In this way, by dividing the power receiving coil 11 into four in the vehicle length direction and the vehicle width direction, it is possible to cope with displacement in the vehicle length direction.

  It is possible to divide the power receiving coil 11 into a larger number of spiral coils. However, as the number of spiral coils increases, the electrical resistance increases accordingly. is there.

  As described above, the embodiments have been described as examples of the technology in the present invention. For this purpose, the accompanying drawings and detailed description are provided.

  Accordingly, among the components described in the accompanying drawings and the detailed description, not only the components essential for solving the problem, but also the components not essential for solving the problem in order to illustrate the above technique. May also be included. Therefore, it should not be immediately recognized that these non-essential components are essential as those non-essential components are described in the accompanying drawings and detailed description.

  Moreover, since the above-mentioned embodiment is for demonstrating the technique in this invention, a various change, replacement, addition, abbreviation, etc. can be performed in a claim or its equivalent range.

  In the above, for the sake of convenience, the technology in the present invention has been described by taking a magnetic resonance type non-contact power feeding system as an example. However, the present invention is not limited to the magnetic field resonance type non-contact power feeding system, and is not limited to an electromagnetic induction type non-contact power feeding system. It can also be applied to a power supply system.

DESCRIPTION OF SYMBOLS 11 Power receiving coil 11a Spiral coil 11b Spiral coil 11c Spiral coil 11d Spiral coil 61 Power transmission coil 16a Rectifier circuit 16b Rectifier circuit

Claims (7)

A non-contact power feeding system in which a power transmission coil installed on the ground and a power receiving coil installed on the lower surface of a vehicle body face each other and perform non-contact power feeding between the power transmission coil and the power receiving coil,
The power transmission coil is composed of one spiral coil;
The power receiving coil is divided into a plurality of spiral coils;
The outer edge shape of the power transmission coil and the outer edge shape of the power receiving coil are substantially the same,
Each shape in which the plurality of spiral coils were divided outer edge of the receiving coil into a plurality possess as outer edge,
The plurality of spiral coils are separated from each other in the vehicle width direction,
The non-contact power feeding system, wherein the plurality of coil cores on which the plurality of spiral coils are respectively placed are separated from each other in the vehicle width direction .   2. The non-contact power feeding system according to claim 1, wherein the plurality of spiral coils are two spiral coils obtained by equally dividing an outer edge shape of the power receiving coil into two in the vehicle width direction.   The non-contact power feeding system according to claim 1, wherein the plurality of spiral coils are three spiral coils obtained by dividing the outer edge shape of the power receiving coil into three in the vehicle width direction. A non-contact power feeding system in which a power transmission coil installed on the ground and a power receiving coil installed on the lower surface of a vehicle body face each other and perform non-contact power feeding between the power transmission coil and the power receiving coil,
The power transmission coil is composed of one spiral coil;
The power receiving coil is divided into a plurality of spiral coils;
Each of the plurality of spiral coils has each shape obtained by dividing the outer edge shape of the power receiving coil into a plurality of outer edge shapes,
The plurality of spiral coils are three spiral coils obtained by dividing the outer edge shape of the power receiving coil into three in the vehicle width direction;
Of the three spiral coils, the width in the vehicle width direction of the spiral coils at both ends is equal to the allowable positional deviation between the power transmission coil and the power reception coil.
A non-contact power feeding system characterized by that . A non-contact power feeding system in which a power transmission coil installed on the ground and a power receiving coil installed on the lower surface of a vehicle body face each other and perform non-contact power feeding between the power transmission coil and the power receiving coil,
The power transmission coil is composed of one spiral coil;
The power receiving coil is divided into a plurality of spiral coils;
Each of the plurality of spiral coils has a shape obtained by dividing the outer edge shape of the power receiving coil into a plurality of outer edge shapes,
The plurality of spiral coils are four spiral coils obtained by dividing the outer edge shape of the power receiving coil into four in the vehicle length direction and the vehicle width direction.
A non-contact power feeding system characterized by that . A non-contact power feeding system in which a power transmission coil installed on the ground and a power receiving coil installed on the lower surface of a vehicle body face each other and perform non-contact power feeding between the power transmission coil and the power receiving coil,
The power transmission coil is composed of one spiral coil;
The power receiving coil is divided into a plurality of spiral coils;
Each of the plurality of spiral coils has each shape obtained by dividing the outer edge shape of the power receiving coil into a plurality of outer edge shapes,
A plurality of rectifier circuits for rectifying the electromotive force generated in each of the plurality of spiral coils;
The outputs of the plurality of rectifier circuits are connected in series,
A non-contact power feeding system characterized by that . A plurality of rectifier circuits for rectifying the electromotive force generated in each of the plurality of spiral coils;
The contactless power feeding system according to claim 1, wherein outputs of the plurality of rectifier circuits are connected in parallel.

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