JP5467569B2 - Non-contact power feeding device - Google Patents

Description

  The present invention relates to a non-contact power supply apparatus that supplies power to a moving body such as an electric vehicle in a non-contact manner.

The non-contact power feeding device supplies electric power from the primary coil to the secondary coil using electromagnetic induction between the primary coil and the secondary coil. The non-contact power supply device is expected to expand its use as a power supply device for charging a secondary battery mounted on an electric vehicle or a plug-in hybrid vehicle.
FIG. 13 shows a power supply system for a plug-in hybrid vehicle using a non-contact power supply device.
A vehicle 100 equipped with a motor 106 as a drive source together with an engine 107 includes a secondary battery 104 that is a power source for the motor 106, an inverter 105 that converts the direct current of the secondary battery 104 into alternating current, The charging circuit 103 of the secondary battery 104 and the secondary coil 102 of the non-contact power feeding device are provided, and the secondary coil 102 is installed outside the floor surface of the vehicle body.
On the other hand, the power supply station side includes an AC power supply 200 having a commercial frequency, an inverter 201 that converts the AC to DC and generates high-frequency AC, and a primary coil 202 of a non-contact power supply apparatus. The coil 202 is installed on the ground.
The driver stops the vehicle 100 so that the secondary coil 102 is directly above the primary coil 202, and starts supplying power to the secondary battery 104.

However, since the positional deviation between the primary coil 202 and the secondary coil 102 when the vehicle is stopped is unavoidable, the vehicle non-contact power feeding device is required to be resistant to the positional deviation.
In addition, since the floor of the vehicle body needs to be separated from the ground to some extent so as not to hinder travel, the non-contact power feeding device for vehicles has a gap length between the primary coil 202 and the secondary coil 102. The ability to supply enough power is required even if it is large.
Further, the secondary coil 102 mounted on the vehicle 100 is required to be small and light.
Up to now, the development of contactless power supply devices that meet these requirements has been intensively advanced.

FIG. 14 schematically shows a cross-sectional shape (a) and a planar shape (b) of the non-contact power feeding device disclosed in Patent Document 1 below. The primary side of the apparatus includes a magnetic core 21 made of a flat ferrite disk and a primary coil 22 wound around one side of the magnetic core 21 in a spiral shape. The secondary side has the same shape as the primary side, and includes a magnetic core 31 made of a ferrite disk and a spiral secondary coil 32 disposed on one side of the magnetic core 31, and the primary coil 22 and the secondary coil 32. Are opposed via a gap g.
This apparatus has a magnetic core 21 and a magnetic core 31 on the back surface of the primary coil 22 and the secondary coil 32, and the magnetic flux does not leak to the back side of the magnetic cores 21, 31. The coupling coefficient between the secondary coils 32 is large, and strong electromagnetic coupling can be obtained. The magnetic flux in this case is indicated by a dotted line D in FIG.
However, when the positions of the primary coil 22 and the secondary coil 32 are shifted, the coupling coefficient rapidly decreases. In order to avoid this, it is necessary to increase the area of the magnetic core 21 and the magnetic core 31 so that the magnetic flux D can be maintained even if the primary coil 22 and the secondary coil 32 are displaced. .

However, a single ferrite plate with a large diameter is difficult to manufacture and is expensive.
Therefore, the following Patent Document 2 describes a non-contact power feeding device for reducing the cost of the core member.
As shown in FIGS. 15A and 15B, this apparatus forms a plate core 213 by combining a large number of rectangular plate blocks 212 made of ferrite, and is flattened on one side of the plate core 213. A coil 222 wound around is disposed. In FIG. 15A and FIG. 15B, two plate-like blocks 212 are overlapped on the portion of the plate-like core 213 located outside the coil 222 and the portion located inside the coil 222, and the coil 222 is located. A large E-shaped core is formed by using one plate-like block 212 as one piece.
Further, in Patent Document 2, as shown in FIG. 16, it is also proposed to reduce the weight of the plate-like core 213 by thinning out the arrangement of the plate-like blocks 212 of the plate-like core 213 for each row.

JP 2008-87733 A JP 2008-120239 A

However, since the non-contact electric power feeders described in Patent Document 1 and Patent Document 2 both have a structure in which a flat ring-shaped coil is arranged on one side of the magnetic core, as shown in FIG. When the width of the coils 22 and 32 is W, the length of the magnetic cores 21 and 31 must be at least greater than 2W.
This coil width W needs to be set to be equal to or greater than the gap length g in order to obtain sufficient electromagnetic coupling between the primary coil 22 and the secondary coil 32.
Further, in order to enable transmission of necessary power even when the positional deviation between the primary coil 22 and the secondary coil 32 occurs, the magnetic pole portions of the primary side core core 21 and the secondary side core core 31 are used. It is necessary to secure a sufficient area where the top and bottom overlap.
Therefore, in the system in which the ring-shaped flat coil is arranged on one side of the magnetic core, the shape of the device, particularly the shape in the width direction, must be increased.
In this method, when a part of the magnetic core is thinned out in order to reduce the weight of the magnetic core, as described in Patent Document 2, the power that can be supplied decreases.

  The present invention was devised in view of such circumstances, and provides a non-contact power feeding device that can cope with a large gap length, is strong against displacement, and can be reduced in size and weight. It is aimed.

The contactless power supply device of the present invention includes a primary coil wound around a primary core and a secondary coil wound around a secondary core, and the primary side A non-contact power feeding device arranged so that a coil and the secondary side coil face each other, wherein the primary side coil or the secondary side coil is wound around a plurality of cores, and the primary side coil or Each of the plurality of cores wound around the secondary coil is composed of a rod-shaped or plate-shaped cuboid having the same shape, and the plurality of cores are opposed to each other with long sides of the cuboid being spaced apart from each other. So that the primary side coil or the secondary side coil is wound in a direction orthogonal to the long side so as to surround the plurality of arranged rectangular parallelepipeds. Features.
In this way, in the structure in which the coil is wound around the core, as shown in FIG. 3, the width occupied by the coil is W and the width occupied by the coil is 2 W (see FIG. 14A). Compared with a method in which a ring-shaped flat coil is disposed on one side of the magnetic core shown in the figure, the size can be extremely reduced. The core is easy to manufacture and can be manufactured at low cost.
In addition , since the magnetic lines of force that fill the gap between the cores are output from the plurality of cores wound by the coil, the primary side core and the secondary side core are expanded with the gap between the cores included in the dimensions. Acts as a core of specified size. Therefore, by providing a gap between the cores, the substantial core area is expanded to an area surrounded by the outer edges of a plurality of parallelepipeds in parallel. For this reason, it is strong against misalignment.

Moreover, in the non-contact electric power feeder of this invention, the opposite side of the side facing the said secondary side coil of the said primary side coil, and the opposite side of the side facing the said primary side coil of the said secondary side coil It is preferable to arrange a conductive plate for preventing leakage of the magnetic field to the outside.
The conductive plate prevents magnetic flux from leaking to the iron plate or the like of the vehicle body and heating the iron plate. The conductive plate also has an effect of increasing the coupling coefficient between the primary side coil and the secondary side coil.

Further, in the non-contact power feeding device according to the present invention, the conductive plate is disposed in close contact with a magnetic pole surface on the opposite side of the opposing magnetic pole surfaces of the primary side core and the secondary side core, and the opposite magnetic pole surface is provided. You may comprise so that the leakage of the magnetic field from may be prevented.
By covering the magnetic pole surface facing the outside of the core with a conductive plate, leakage of the magnetic field to the outside can be effectively prevented.
In the contactless power supply device of the present invention, the conductive plate is formed using an aluminum plate or the like.

In the non-contact power feeding device according to the present invention, the outer area connecting the outer shapes of the plurality of primary cores wound by the primary coil is a plurality of windings wound by the secondary coil. It may be made larger than the outer area connecting the outer shapes of the secondary cores.
By doing so, it is possible to make the secondary side coil mounted on a vehicle or the like more resistant to misalignment while reducing the size and weight.

  Moreover, the non-contact electric power feeder of this invention can comprise the said core with a ferrite, and can comprise the said primary side coil and the secondary side coil by winding a litz wire.

Moreover, the non-contact electric power feeder of this invention can install the said primary side coil in the ground electric power feeding station, and can install the said secondary side coil in the mobile body which receives electric power feeding from the said electric power feeding station.
Moreover, the non-contact power feeding device of the present invention is suitable for power feeding of vehicles.

Moreover, in the non-contact electric power feeder of this invention, it is preferable to set so that the longitudinal direction of the said primary side core and secondary side core arranged in parallel may correspond with the advancing direction of the said mobile body.
If the cores are arranged in a direction in which the moving body causes a positional shift, even when a positional shift occurs, there is an opposing core between the primary side core and the secondary side core, and power feeding becomes possible. The traveling direction of the vehicle or the like can be set so that the positional deviation does not occur due to a curbstone or the like, but the lateral direction is likely to be displaced. Therefore, by aligning the longitudinal direction of the core with the traveling direction so that the cores are arranged in the lateral direction, it is possible to cope with the lateral displacement of the vehicle.

Since the non-contact power feeding device of the present invention includes a core having a substantially enlarged size in which gaps between a plurality of cores are added to the dimensions, the positional deviation between the primary side coil and the secondary side coil It can cope with enough.
Further, by providing a gap between the plurality of cores, a large core area can be secured with a small amount of the core material, so that the weight of the apparatus can be reduced.
Further, the core can be easily manufactured, and the manufacturing cost can be reduced.
In addition, since the coil is wound around the core, the apparatus can be downsized.

The figure which shows the coil (a-1, a-2) used with the non-contact electric power feeder which concerns on the 1st Embodiment of this invention, and a comparative example (b-1, b-2). The figure which shows the core of the coil of FIG. The figure which shows arrangement | positioning of the primary side coil and secondary side coil of the non-contact electric power feeder which concerns on the 1st Embodiment of this invention. The figure which shows the modification of the electrically conductive board arrange | positioned at a primary side coil and a secondary side coil The figure which shows the magnetic force line of the coil of FIG. The figure which shows the characteristic comparison of the coil which arranges the core in the interval and the comparative example The figure which shows the modification of the primary side coil of the non-contact electric power feeder which concerns on the 1st Embodiment of this invention, and a secondary side coil The figure which shows the state which mounted the secondary side coil in the vehicle The figure which shows the coil used with the non-contact electric power feeder which concerns on the 2nd Embodiment of this invention. The figure which shows the magnetic force line of the coil of FIG. The figure which shows the modification of the primary side coil and secondary side coil of the non-contact electric power feeder which concerns on the 2nd Embodiment of this invention. The figure which shows the coil arrange | positioned radially used with the non-contact electric power feeder which concerns on the 2nd Embodiment of this invention Diagram showing power supply system for plug-in hybrid vehicle The figure which shows the coil of the conventional non-contact electric power feeder The figure which shows the other coil of the conventional non-contact electric power feeder The figure which shows the conventional coil which thins out the core part

(First embodiment)
In the non-contact power feeding device according to the first embodiment of the present invention, the primary side coil and the secondary side coil are both a plan view of FIG. 1 (a-1) and a side view of FIG. 1 (a-2). As shown in FIG. 3, a plurality of (four) rectangular parallelepiped plate-like cores 41 formed of ferrite and a winding coil 42 formed by winding litz wires so as to surround the four plate-like cores 41 are provided. I have. The four plate cores 41 are arranged in parallel at equal intervals on one plane, and the winding coil 42 is arranged in the longitudinal direction of the plate core 41 so that both ends of each plate core 41 are exposed. It is wound in an orthogonal direction.
1 (b-1) and 1 (b-2) are coils described for comparison. The coil includes a flat core 43 made of a single ferrite plate and a winding coil 44. FIG. ing. The flat core 43 has an area where the four plate cores 41 are combined, and the size of the plate core 41 is indicated by a dotted line in the flat core 43 in order to show the area.
FIG. 2 shows the plate core 41 and the flat core 43 from which the winding coils 42 and 44 are removed.

FIG. 3 shows a state in which the winding coil 42 of the primary side coil 40 and the winding coil 52 of the secondary side coil 50 of the non-contact power feeding device are arranged to face each other with a gap g interposed therebetween. It is sectional drawing shown. On the back surface of the primary side coil 40 and the secondary side coil 50, an aluminum plate 60 for preventing magnetic field leakage described later is disposed.
Since the winding coils 42 and 52 are wound around the plate cores 41 and 51, the width of the winding coils 42 and 52 occupying the plate cores 41 and 51 is W. This coil width W needs to be set to a gap length g or more in order to sufficiently obtain the electromagnetic coupling between the primary side coil 40 and the secondary side coil 50. However, a ring shape is formed on one side of the conventional magnetic core. Compared with the method of arranging flat coils (FIG. 14A), the area occupied by the coil width is small, which is advantageous for downsizing.

When a high frequency current is applied to the winding coil 42 of the primary side coil 40, a magnetic field is generated inside the winding coil 42, and the magnetic flux flows from the plate core 41 into the plate core 51 of the secondary coil 50. Thus, an induced current flows through the winding coil 52, so that a magnetic field is generated, and the magnetic flux flows from the plate core 51 into the plate core 41 of the primary coil 40.
At this time, a part of the magnetic flux emitted from the plate-like core 41 and the plate-like core 51 leaks to the outside. When this leakage magnetic flux passes through an iron plate that constitutes the floor surface of the car, the iron plate is heated. The aluminum plate 60 is arranged to prevent such a situation. The flow of magnetic flux in this non-contact power feeding device is shown by a dotted line in FIG.
Moreover, in order for the aluminum plate 60 to suppress the magnetic flux which goes outside, the magnetic flux which circulates between the primary side coil 40 and the secondary side coil 50 increases, and a coupling coefficient increases.

  In addition, as shown in FIG. 4, the aluminum plate 62 arrange | positioned at the back surface of the primary side coil 40 and the secondary side coil 50 is made into the plate-shaped core 41 of the primary side, and the plate-shaped core 51 of the secondary side. If the magnetic pole surface facing the outside of the plate-like cores 41 and 51 is covered with the aluminum plate 62 while being in close contact with the magnetic pole surface on the opposite side of the opposing magnetic pole surface, the leakage of the magnetic field to the outside is more effective. Can be prevented.

Fig.5 (a) has shown typically the magnetic force line emitted from the plate-shaped core 41 when it sees from the direction of Fig.1 (a-2). The same applies to the plate-like core 51. FIG. 5B schematically shows lines of magnetic force generated from one flat core 43 for comparison.
Since each of the plurality of plate-like cores 41 generates magnetic lines of force from the periphery thereof, even if there is a gap between the plate-like cores 41, the generation distribution of the lines of magnetic force is not interrupted thereby. The distribution of the lines of magnetic force generated by the plurality of plate-like cores 41 is substantially equal to the distribution of the lines of magnetic force emitted from the flat plate core 43. Therefore, the plurality of plate-like cores 41 arranged in parallel at intervals can be regarded as a flat plate core 43 having an enlarged area.
That is, as shown in FIG. 2, the core area can be expanded to (A × b) by using the same amount of core material as the flat core 43 having an area of (a × b).
Moreover, compared with the production of the flat plate core 43 of a single plate, the production of the plate core 41 is extremely easy, and the manufacturing cost can be greatly reduced.

Such substantial enlargement of the core area makes it possible to suppress a decrease in power supply capability due to the positional deviation between the primary side coil 40 and the secondary side coil 50, and the resistance to the positional deviation is enhanced.
In other words, since the core area having resistance to misalignment can be configured with a small amount of core material, the weight of the apparatus can be reduced.

FIG. 6 shows the results of measuring the characteristics of a coil (FIG. 6A) in which a plurality of plate-shaped cores are arranged in parallel with a gap and a coil having a core without a gap (FIG. 6B). Show. Here, the plate-like cores in FIG. 6A are arranged in an amount 3/5 that of the core in FIG. 6B so as to occupy the same area (240 mm × 250 mm).
In the measurement, the primary side coil and the secondary side coil are set in the shape of FIG. 6A or FIG. 6B, the primary side coil and the secondary side coil are shifted in the x direction, and the shifted distance x (Mm), AC power supply voltage (V _AC ), feeding power (P _OUT ), and feeding efficiency η _C are measured.
FIG. 6 (c) shows the measurement result. The horizontal axis represents the distance x (mm) shifted, and the vertical axis represents the AC power supply voltage (V _AC ), the feed power (P _OUT ), and the feed efficiency η _C. Represents each value. In the figure, the characteristics of the coil of FIG. 6A are indicated by solid lines, and the characteristics of the coil of FIG. 6B are indicated by dotted lines.
From FIG. 6 (c), the coil of FIG. 6 (a) has almost the same feeding characteristics and misalignment characteristics as the coil of FIG. 6 (b) although the amount of the core material is reduced to 3/5. You can see that it does n’t change. Therefore, the configuration in which the gap is provided between the plate-like cores as shown in FIG. 6A is advantageous in reducing the weight and cost of the coil.

  Further, as shown in FIG. 7, the number of plate cores 41 surrounded by the winding coil 42 of the primary coil 40 is increased, and the outer area connecting the outer shapes of the plurality of plate cores 41 (FIG. 2 (a-1 ) (A × b)) is set to be larger than the outer area of the plurality of plate-like cores 51 of the secondary coil 50, the positional deviation of the secondary coil 50 with respect to the primary coil 40 is shifted. More acceptable. In a power feeding system such as an electric vehicle, the primary side coil 40 is installed in the power feeding station, and the secondary side coil 50 is mounted on the vehicle. With this configuration, the position shift can be prevented without increasing the mounting weight on the vehicle. Resistance can be increased.

  Further, as shown in FIG. 8, the secondary coil 50 is mounted on the vehicle 61 so that the traveling direction (front-rear direction) of the vehicle 61 coincides with the longitudinal direction of the plate-like core 51, and the primary coil 40. Are installed in the power supply station in the same direction, the tolerance is improved against the positional deviation of the vehicle 61 in the lateral direction (direction perpendicular to the traveling direction). The stop position in the front-rear direction of the vehicle 61 can be set using a curbstone or the like so as not to be displaced, but the lateral direction is likely to be displaced. However, if the primary side coil and the secondary side coil are installed in the direction of FIG. 8, even if the stop position of the vehicle 61 is shifted in the horizontal direction, the opposing plate cores 41 and 51 can be secured. It becomes strong against the position shift.

In addition, although the example which winds a plate-shaped core with a winding coil was demonstrated here, it may replace with a plate-shaped core and a rod-shaped rectangular parallelepiped, a rod-shaped body with a circular cross section, etc. may be used.
The core material may be formed using a magnetic material other than ferrite, for example, a ferromagnetic material with low AC loss, such as a dust core or a silicon steel plate, and the wound coil is made of a wire other than a litz wire. Also good. For preventing magnetic field leakage, a conductive plate other than an aluminum plate may be used.
Moreover, the number of the plate-like cores shown here is an example, and can be set arbitrarily.
Moreover, although it is preferable to set the space | interval between plate-shaped cores larger than 0, you may make this space | interval 0.
In addition, here, power supply to an electric vehicle has been described. However, the present invention can also be used for power supply to a moving object such as a factory transport vehicle or a mobile robot.

(Second Embodiment)
As shown in the plan view of FIG. 9A and the side view of FIG. 9B, the non-contact power feeding device according to the second embodiment of the present invention includes a primary side coil and a secondary side coil. Each of the plate-like cores 71 is constituted by winding coils 72 wound individually around each of the plate-like cores 71, and the plate-like cores 71 around which the winding coils 72 are wound are arranged at equal intervals on a plane.

  FIG. 10 schematically shows lines of magnetic force generated from the plate-like core 71 when viewed from the direction of FIG. 9B. In this case as well, a distribution substantially equivalent to the distribution of the lines of magnetic force emitted from one flat core can be obtained as in FIG. Therefore, by arranging the plurality of plate-like cores 72 at intervals, the core area can be substantially enlarged, and resistance to displacement can be increased.

Further, as shown in the perspective view (a) and the side view (b) of FIG. 11, the number of the plate-like cores 71 wound around the winding coil 72 of the primary coil 70 is determined by the number of the secondary coils 80. By increasing the number of the plate-like cores 81 wound by the winding coil 82, as in the case of FIG. 7, it is possible to reduce the size and weight of the secondary coil mounted on the moving body, while reducing the position shift. Resistance can be increased.
Further, in this case, if only the winding coil 72 facing the winding coil 82 of the secondary side coil 80 among the winding coils 72 of the primary side coil 70 is selectively energized, The power consumption of the contact power supply device can be saved and the operation efficiency can be improved.

Further, the plurality of plate-like cores 71 in which the winding coils 72 are individually wound can be arranged radially as shown in FIG.
In the first embodiment, a case where a plurality of plate cores are wound so as to be surrounded by a winding coil is shown, and in the second embodiment, each of the plurality of plate cores is wound individually. Although the case where it winds with a coil was shown, it is also possible to comprise one side of a primary side coil and a secondary side coil by the system of a 1st embodiment, and the other by the system of a 2nd embodiment. is there.

  The non-contact power feeding device of the present invention is resistant to misalignment, and can be reduced in size, weight, and cost, and can be used for various types of mobile objects such as electric vehicles, plug-in hybrid vehicles, factory transport vehicles, and mobile robots. It can be used for non-contact power feeding.

40 Primary side coil 41 Plate-like core 42 Winding coil 43 Flat core 50 Secondary side coil 51 Plate-like core 52 Winding coil 60 Conductive plate 61 Vehicle 62 Conductive plate 70 Primary side coil 71 Plate-like core 72 Winding coil 80 Secondary coil 81 Plate core 82 Winding coil

Claims (9)

A primary coil wound around a primary core and a secondary coil wound around the secondary core, wherein the primary coil and the secondary coil are A non-contact power feeding device arranged to face each other,
The primary side coil or the secondary side coil is wound around a plurality of cores, and each of the plurality of cores wound around the primary side coil or the secondary side coil has the same shape as a rod or It consists of a plate-shaped rectangular parallelepiped, and the plurality of cores are arranged in parallel on a plane so that the long sides of the rectangular parallelepiped face each other with a gap between them,
The non-contact power feeding device, wherein the primary side coil or the secondary side coil is wound in a direction orthogonal to the long side so as to surround the plurality of arranged rectangular parallelepipeds. 2. The non-contact power feeding device according to claim 1 , wherein the side of the primary coil opposite to the side facing the secondary coil and the side of the secondary coil facing the primary side coil are set. The non-contact electric power feeder characterized by arrange | positioning the electrically conductive board which prevents the leakage of the magnetic field to the exterior on each of the other side. 3. The non-contact power feeding apparatus according to claim 2 , wherein the conductive plate is disposed in close contact with a magnetic pole surface on the opposite side of the opposing magnetic pole faces of the primary side core and the secondary side core. The non-contact electric power feeder characterized by preventing the leakage of the magnetic field from the magnetic pole surface. A non-contact power feeding device according to claim 2 or 3, non-contact power feeding device, wherein the conductive plate is characterized in that a plate of aluminum. 2. The contactless power supply device according to claim 1 , wherein an outer area connecting the outer shapes of the plurality of primary cores wound around the primary coil is wound around the secondary coil. A non-contact power feeding apparatus, wherein the outer area is larger than an outer area connecting the outer shapes of the plurality of secondary cores. The contactless power supply device according to any one of claims 1 to 5 , wherein the core is made of a ferrite or a dust core, and the primary side coil and the secondary side coil are formed by winding a litz wire. A non-contact power feeding device. A non-contact power feeding device according to any one of claims 1 to 6, wherein the primary coil is installed on the ground of the power supply station, the secondary coil, installed in the moving body receives power from the power supply station The non-contact electric power feeder characterized by the above-mentioned. The contactless power supply device according to claim 7 , wherein the moving body is a vehicle. A non-contact power feeding device according to claim 7 or 8, non, wherein the longitudinal direction of the primary core and the secondary core are arranged in parallel matches the traveling direction of the moving body Contact power supply device.