JP2022150893A - power supply - Google Patents

Abstract

To reduce leakage magnetic flux of a power supply device.SOLUTION: A power supply device 1 includes: a power supply coil 11; a power receiving coil 13; a first core 12 around which the power supply coil 11 is wound; a second core 14 around which the power receiving coil 13 is wound; and shield members 15a, 15b for covering the entire periphery of the power supply coil 11 and the entire periphery of the power receiving coil 13. The shield members 15a, 15b include a conductor 20 and an insulator 21. The conductor 20 has a first end 20a and a second end 20b disposed so as to face with each other. The insulator 21 is disposed between the first end 20a and the second end 20b of the conductor 20.SELECTED DRAWING: Figure 4

Description

The present invention relates to a power supply device that wirelessly supplies power.

2. Description of the Related Art In recent years, wireless power supply (non-contact power supply), which does not use a power cord or a power transmission cable, has been adopted as a system for supplying power to a battery mounted on an electric vehicle (EV), an automatic guided vehicle (AGV), or the like.

For example, Patent Literature 1 discloses a power supply device that utilizes electromagnetic resonance. The power supply device includes a power supply unit provided in the power supply facility and a power reception unit mounted on the vehicle.

The power supply unit includes a power supply side coil unit to which high-frequency power is supplied from a power supply. The power feeding side coil unit includes a power feeding side coil, a power feeding side core around which the power feeding side coil is wound, and a power feeding side shield case that houses the power feeding side coil and the power feeding side core.

The power-supply-side shield case is composed of a metal shield using copper or aluminum. The power-supply-side shield case has a bottom wall that covers a part of the power-supply-side core around which the power-supply-side coil is wound, and vertical walls that stand upright from the periphery of the bottom wall, and is configured in a partially open box shape. (see paragraph 0021 of the same document).

The power receiving unit includes a power receiving side coil unit. The power receiving side coil unit includes a power receiving side coil that electromagnetically resonates with the power feeding side coil, a power receiving side core around which the power receiving side coil is wound, and a power receiving side shield case that houses the power receiving side coil and the power receiving side core. .

The power-receiving-side shield case is made of a metal shield, like the power-supply-side shield case. The power-receiving-side shield case includes a bottom wall that partially covers the power-receiving-side coil and vertical walls that stand upright from the periphery of the bottom wall, and is configured in a partially open box shape (paragraph 0027 of the same document). reference).

JP 2014-179438 A

In the conventional power supply device, since the shield case on the power supply side and the shield case on the power reception side are partially opened, part of the power supply side coil and part of the power reception side coil are exposed from the respective shield cases. Become. For this reason, leakage magnetic flux occurs from the exposed portion of each coil, resulting in a decrease in power transmission efficiency.

The present invention has been made in view of the above circumstances, and a technical object of the present invention is to reduce the leakage magnetic flux of a power supply device.

The present invention is intended to solve the above problems, and includes a power supply coil, a power reception coil, a first core around which the power supply coil is wound, a second core around which the power reception coil is wound, and and a shield member that covers the entire periphery of the power supply coil and the entire periphery of the power reception coil, wherein the shield member includes a conductor and an insulator, and the conductors face each other. having a first end and a second end arranged in such a manner that the insulator is disposed between the first end and the second end.

According to such a configuration, by covering the entire circumference of the power supply coil wound around the first core and the entire circumference of the power reception coil wound around the second core with the shield member, exposure of each coil and each core is prevented. Therefore, it is possible to reduce the leakage magnetic flux of the power supply device. In addition, by insulating the first end and the second end of the shield member with an insulator so that they are not electrically connected, it is possible to suppress eddy currents generated in the conductor when power is supplied. As described above, it is possible to improve the power transmission efficiency of the power supply device.

The power supply device described above may include a guide portion for guiding the first core or the second core to a position where power can be supplied. This guide portion enables each coil and each core to be accurately arranged at a position where power can be supplied.

Advantageous Effects of Invention According to the present invention, it is possible to reduce the leakage magnetic flux of the power supply device.

It is a circuit diagram of a power supply device. It is a top view which shows the magnetic field coupling part of an electric power feeder. FIG. 3 is a cross-sectional view along the line III-III of FIG. 2; FIG. 3 is a sectional view taken along line IV-IV in FIG. 2; It is a top view of a shield member. It is a top view which shows the magnetic coupling part of the electric power feeder which concerns on other embodiment. FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 6; It is a top view which shows the magnetic coupling part of the electric power feeder which concerns on other embodiment. It is a top view which shows the magnetic coupling part of the electric power feeder which concerns on other embodiment. It is a top view which shows the magnetic coupling part of the electric power feeder which concerns on other embodiment. It is a top view which shows the magnetic coupling part of the electric power feeder which concerns on other embodiment. It is a top view which shows the magnetic coupling part of the electric power feeder which concerns on other embodiment. 4 is a graph showing measurement results of leakage inductance; 4 is a graph showing measurement results of magnetizing inductance;

EMBODIMENT OF THE INVENTION Hereinafter, it demonstrates, referring drawings for the form for implementing this invention. 1 to 5 show an embodiment of a power supply device according to the invention. In this embodiment, a magnetic field coupling type power supply device is exemplified.

The power supply device can be used, for example, in charging systems for electric vehicles (EV), automatic guided vehicles (AGV), and the like. The power supply device is not limited to this, and can be used for other power supply systems. In this embodiment, as an example, a case where the power supply device is used in a charging system for an automatic guided vehicle will be described.

As shown in FIG. 1, a power supply device 1 includes a power supply unit 2 as a primary circuit provided in a charging station, a power receiving unit 3 as a secondary circuit provided in an automatic guided vehicle, and receiving power from the power supply unit 2 by magnetic coupling. a magnetic coupling portion 4 that enables the transmission of power to the portion 3 .

The power supply unit 2 includes a power supply 5 and a switching circuit 6, for example. The switching circuit 6 is composed of, for example, an H bridge circuit including four switching elements 7a and diodes 7b, and a capacitor 7c. Power supply unit 2 converts a DC voltage applied by power supply 5 into a square wave AC voltage by switching circuit 6 .

The power receiving unit 3 includes, for example, a rectifier circuit 8 and a battery 10 as a secondary battery. The rectifier circuit 8 is composed of four diodes 9b each having a resonance capacitor 9a connected in parallel, and a smoothing capacitor 9c. The power receiving unit 3 converts the AC voltage transmitted from the power feeding unit 2 into a DC voltage by the rectifier circuit 8 and charges the battery 10 .

As shown in FIGS. 2 to 4 , the magnetic field coupling unit 4 includes a power supply coil 11 connected to the power supply unit 2 , a first core 12 around which the power supply coil 11 is wound, and a power receiving unit 3 connected to the power receiving unit 3 . It includes a coil 13, a second core 14 around which the receiving coil 13 is wound, and shield members 15a and 15b for suppressing leakage magnetic flux.

The power feeding coil 11 and the power receiving coil 13 are made of insulated wires, which are wound around the cores 12 and 14 with a predetermined number of turns.

The first core 12 and the second core 14 are made of magnetic material such as ferrite. Each of the cores 12 and 14 is configured in a U shape in plan view. The first core 12 has a pair of straight portions 16 and a connecting portion 17 that connects the straight portions 16 together. Similarly, the second core 14 has a pair of straight portions 18 and a connecting portion 19 that connects the straight portions 18 together. Each straight portion 16, 18 of each core 12, 14 has an end surface 16a, 18a at its projecting end.

As shown in FIG. 4, each core 12, 14 has a rectangular cross section, but the cross section is not limited to this shape. Each core 12, 14 has a first surface 12a, 14a, a second surface 12b, 14b, a third surface 12c, 14c, and a fourth surface 12d, 14d corresponding to each side of the rectangular shape.

The shield members 15 a and 15 b include a first shield member 15 a that covers the power feeding coil 11 and the first core 12 and a second shield member 15 b that covers the power receiving coil 13 and the second core 14 .

As shown in FIGS. 3 and 4, each shield member 15a, 15b includes a conductor 20 and an insulator 21. As shown in FIG. The conductor 20 is composed of, for example, a metal foil, a metal sheet, or the like. Examples of metals used for the conductor 20 include aluminum and copper.

The insulator 21 is formed integrally with the insulator 21 by applying an insulating adhesive to the conductor 20, or by attaching an insulating resin sheet or resin film made of polyurethane or the like to the conductor 20. be done.

FIG. 5 shows the shield members 15a, 15b before being attached to each coil 11, 13 and each core 12, 14. FIG. The conductor 20 of each of the shield members 15a and 15b has a rectangular shape in plan view, but is not limited to this shape and may have another shape. The conductor 20 has a first end 20a and a second end 20b. Each of the ends 20a and 20b is covered with an insulator 21 on both front and back surfaces and end faces.

As shown in FIG. 4, when the shield members 15a and 15b are attached to the cores 12 and 14, the first end 20a and the second end 20b of the conductor 20 overlap each other. In this state, the first end portion 20a and the second end portion 20b face each other in the thickness direction or the radial direction of each coil 11,13. The insulator 21 is located between the first end 20a and the second end 20b facing each other to insulate them.

In this state, the feed coil 11 is covered with the first shield member 15a all around. Further, all of the first surface 12a to the fourth surface 12d of the first core 12 around which the feeding coil 11 is wound are covered with the first shield member 15a. The power receiving coil 13 is entirely covered with the second shield member 15b. Further, the second core 14 around which the power receiving coil 13 is wound is covered with the second shield member 15b from the first surface 14a to the fourth surface 14d.

Note that the first shield member 15a is not superimposed on the end surface 16a of the straight portion 16 of the first core 12 . In addition, the second shield member 15b is not superimposed on the end surface 18a of the straight portion 18 of the second core 14 .

When the battery 10 needs to be charged, the power feeding coil 11, the first core 12, the power receiving coil 13, and the second core 14 are arranged at positions where power can be fed (hereinafter referred to as "power feeding positions"). 2 and 3 show the coils 11, 13 and the cores 12, 14 arranged at the feeding position.

At the feeding position, the end face 18a of the straight portion 18 of the second core 14 faces the end face 16a of the straight portion 16 of the first core 12 . In this embodiment, the end face 18a of the second core 14 is in contact with the end face 16a of the first core 12, but the configuration is not limited to this. The end face 18a of the second core 14 may be separated from the end face 16b of the first core 12 at the power feeding position as long as power can be supplied.

According to the power supply device 1 according to the present embodiment described above, by covering the entire circumference of the power supply coil 11 and the entire circumference of the power reception coil 13 with the shield members 15a and 15b, exposure of the power supply coil 11 and the power reception coil 13 is prevented. can be eliminated. Thereby, it becomes possible to reduce the leakage magnetic flux of the power supply device 1 .

Also, the magnetic fields generated by the coils 11 and 13 can be reflected toward the cores 12 and 14 by the conductor 20 . Furthermore, the first end 20a and the second end 20b of the shield members 15a and 15b are insulated by the insulator 21 so that they are not electrically connected, thereby suppressing the eddy current generated in the conductor 20 during power supply. can. As a result, the coupling coefficient in the magnetic field coupling unit 4 can be increased, and power can be efficiently transmitted by the power supply device 1 .

6 to 12 show other embodiments of the power supply device (magnetic field coupling section) according to the present invention.

In the examples shown in FIGS. 6 and 7, the shield members 15a to 15c of the magnetic coupling portion 4 are part of the straight portion 16 of the first core 12 in addition to the first shield member 15a and the second shield member 15b. A third shield member 15c that covers the second core 14 and part of the straight portion 18 is included. In this example, the linear portions 16 and 18 of the respective cores 12 and 14 are partially covered by the first shield member 15a and the second shield member 15b on the side of the connecting portions 17 and 19, and partially on the side of the end faces 16a and 18a. is covered by the third shield member 15c.

The third shield member 15c has a cylindrical or tubular shape, and has a space inside that can accommodate a portion of the straight portion 16 of the first core 12 and a portion of the straight portion 18 of the second core 14 . The third shield member 15c has a first opening 22 into which the linear portion 16 of the first core 12 can be inserted, and a second opening 23 into which the linear portion 18 of the second core 14 can be inserted. The third shield member 15 c is fixed to the first core 12 with a portion of the straight portion 16 of the first core 12 inserted into the first opening 22 .

In addition, the coils 11 and 13 are not wound on the portions of the straight portions 16 and 18 of the cores 12 and 14 that are accommodated in the third shield member 15c.

FIG. 6 shows the state immediately before the second core 14 is arranged at the feeding position. From this state, by inserting the end (end face 18a) of the straight portion 18 of the second core 14 into the second opening 23 of the third shield member 15c, the third shield member 15c moves the second core 14 to the feeding position. can guide you to That is, the third shield member 15c also functions as a guide portion that guides the second core 14 to the power feeding position. Further, the third shield member 15c is arranged such that the end surface 16a of the first core 12 and the end surface 18a of the second core 14 are in contact with each other without deviation after the second core 14 is placed at the feeding position. 12, 14 positioning can be performed.

As shown in FIG. 7, the third shield member 15c includes a conductor 20 and an insulator 21, like the first shield member 15a and the second shield member 15b. In this example, the first end 20a and the second end 20b of the conductor 20 do not overlap. The first end portion 20a and the second end portion 20b face each other in the circumferential direction of the coils 11 and 13 with the insulator 21 interposed therebetween. The insulator 21 is positioned between and connects the first end 20a and the second end 20b. The third shield member 15c is not limited to this example, and has a structure in which the first end portion 20a and the second end portion 20b overlap with the insulator 21 interposed therebetween, similarly to the first shield member 15a and the second shield member 15b. may have.

In the example shown in FIG. 8, the third shield member 15c is fixed to the end of the linear portion 18 of the second core 14 of the magnetic field coupling portion 4. As shown in FIG. A portion of the straight portion 18 of the second core 14 is inserted in advance from the second opening 23 of the third shield member 15c. In this state, the third shield member 15c is fixed to the straight portion 18 of the second core 14. As shown in FIG.

When the power receiving coil 13 and the second core 14 are moved to the power feeding position, the second core 14 approaches the first core 12, and the second opening 23 of the third shield member 15c is aligned with the straight line in the first core 12. The end of portion 16 is inserted. After that, the second core 14 moves, guided by the third shield member 15 c , to the feeding position where the end face 18 a of the straight portion 18 contacts the end face 16 a of the straight portion 16 of the first core 12 .

In the example shown in FIG. 9, a part of the straight part 16 of the first core 12 and a part of the straight part 18 of the second core 14 are inserted into the conductor 20 of the third shield member 15c in the magnetic coupling part 4. It comprises a first portion 24 and a second portion 25 integrally formed with the first portion 24 .

The first portion 24 has a first opening 22 and a second opening 23, similar to the third shield member 15c illustrated in FIGS. The third shield member 15c is fixed to the straight portion 16 of the first core 12 in a state in which a portion of the straight portion 16 is inserted from the first opening 22 of the first portion 24 in advance.

The second portion 25 functions as a guide portion that guides the straight portion 18 of the second core 14 to the second opening 23 of the first portion 24 . An inner surface 25 a of the second portion 25 is inclined at a predetermined angle with respect to the first portion 24 .

When moving the power receiving coil 13 and the second core 14 to the power feeding position, if the position of the second core 14 deviates from the intended position, part of the straight portion 18 of the second core 14 will be removed from the third shield member. It first contacts the inner surface 25a of the second portion 25 before being inserted into the first portion 24 of 15c.

After that, the linear portion 18 of the second core 14 slides in contact with the inner surface 25a of the second portion 25 as the second core 14 moves, until it reaches the second opening 23 of the first portion 24. be guided. This makes it possible to accurately move the second core 14 to the feeding position while correcting the positional deviation of the second core 14 .

In the example shown in FIG. 10, the conductor 20 of the third shield member 15c in the magnetic coupling section 4 has a first portion 24, a second portion 25, and a third portion 26. In the example shown in FIG. The configuration of the first portion 24 is the same as that of the third shield member 15c shown in FIGS.

The second portion 25 is formed on the first opening 22 side of the first portion 24 . The second portion 25 is superimposed on the outside of the first shield member 15a covering part of the straight portion 16 of the first core 12 . That is, the second portion 25 functions as a covering portion that covers a portion of the first shield member 15a. The second portion 25 is fixed to a portion of the first shield member 15a.

The third portion 26 is formed on the second opening 23 side of the first portion 24 . The third portion 26 is superimposed on the outside of the second shield member 15b covering part of the straight portion 18 of the second core 14 when the second core 14 is placed at the power feeding position. That is, the third portion 26 functions as a covering portion that covers a portion of the second shield member 15b.

When moving the power receiving coil 13 and the second core 14 to the power feeding position, the end of the straight portion 18 of the second core 14 is inserted into the third shield member 15c from the third portion 26 . The ends of the straight portions 18 pass through the interior of the third portion 26 without contacting the inner surface of the third portion 26 . The end of this straight portion 18 is then inserted into the second opening 23 of the first portion 24 . Further, a portion of the second shield member 15b covering the straight portion 18 of the second core 14 is inserted inside the third portion 26 related to the third shield member 15c.

When the end face 18a of the straight portion 18 of the second core 14 moves to the feeding position where it contacts the end face 16a of the straight portion 16 of the first core 12, a part of the second shield member 15b is replaced by the third shield member 15c. It becomes a state covered by the third portion 26 .

In the example shown in FIG. 11, of the two third shield members 15c in the magnetic field coupling portion 4, one third shield member 15c is fixed in advance to one of the pair of straight portions 16 related to the first core 12, and the other A third shield member 15c is fixed in advance to one of the pair of linear portions 18 related to the second core 14 .

When the power receiving coil 13 and the second core 14 are moved to the power feeding position, if the second core 14 is brought close to the first core 12, the first opening 22 of the third shield member 15c provided in the second core 14 is opened. , the end of the straight portion 16 of the opposing first core 12 is inserted. In addition, the end of the linear portion 18 of the facing second core 14 is inserted into the second opening 23 of the third shield member 15c provided in the first core 12 . The second core 14 moves to the feeding position while being guided by each third shield member 15c.

In the example shown in FIG. 12, the shield members 15a to 15d include the first shield member 15a to the third shield member 15c already described, and a fourth shield member 15d engaged with the third shield member 15c. The third shield member 15c is fixed in advance to the straight portion 16 of the first core 12, and the fourth shield member 15d is fixed in advance to the straight portion 18 of the second core 14. As shown in FIG.

The fourth shield member 15d has a first opening 27 into which the straight portion 18 of the second core 14 is inserted, and a second opening 28 into which the third shield member 15c is inserted. The fourth shield member 15 d is fixed to the straight portion 18 of the second core 14 while the straight portion 18 is inserted into the first opening 27 . A part of the straight portion 18 of the second core 14 is housed inside the fourth shield member 15d. In this state, the inner surface of the fourth shield member 15d is not in contact with the first to fourth surfaces 14a to 14d of the second core 14 and is separated from these surfaces 14a to 14d. That is, between the inner surface of the fourth shield member 15d and the surfaces 14a to 14d of the second core 14, gaps are formed into which a portion of the third shield member 15c is inserted.

When the power receiving coil 13 and the second core 14 are moved to the power feeding position, when the second core 14 is brought closer to the first core 12, the third shield member 15c fixed to the straight portion 16 of the first core 12 is moved to the power feeding position. It is inserted into the second opening 28 of the four shield members 15d.

As the second core 14 moves further toward the first core 12, the fourth shield member 15d approaches the first core 12 while being guided by the outer surface of the third shield member 15c. Thereby, the straight portion 18 of the second core 14 positioned inside the fourth shield member 15d is inserted into the second opening 23 of the third shield member 15c. After that, the second core 14 moves to the feeding position where the end face 18 a of the straight portion 18 contacts the end face 16 a of the straight portion 16 of the first core 12 .

In addition, the present invention is not limited to the configuration of the above-described embodiment, nor is it limited to the above-described effects. Various modifications can be made to the present invention without departing from the gist of the present invention.

Although the first shield member 15a to the fourth shield member 15d are configured by separate members in the above embodiment, the present invention is not limited to this configuration. For example, the third shield member 15c or the fourth shield member 15d may be configured integrally with the first shield member 15a or the second shield member 15b.

In the above embodiment, the insulator 21 covering only the ends 20a and 20b of the conductor 20 is illustrated, but the insulator 21 is not limited to this, and the insulator 21 covers the entire surface of the conductor 20 (the ends 20a and 20b). and all of the front and back surfaces) may be coated.

Although the above-described embodiment exemplifies the power supply device 1 having a configuration in which the second core 14 moves toward the first core 12, the present invention is not limited to this configuration. The power supply device 1 may be configured such that the first core 12 moves toward the second core 14, or both the first core 12 and the second core 14 may be configured to be movable.

Examples of the present invention will be described below, but the present invention is not limited to these examples.

In order to confirm the effects of the present invention, the inventors measured the excitation inductance and leakage inductance in the electromagnetic coupling portion of the power supply device. In order to achieve suitable power transmission, it is desirable to reduce the leakage inductance in the electromagnetic coupling portion without reducing the excitation inductance.

An example was obtained by covering the power feeding coil, first core, receiving coil, and second core in the power feeding device illustrated in FIG. 2 with an aluminum foil as a shield member. In the example, the ends of the aluminum foil were overlapped and an insulating resin was placed between the ends. In addition, a power supply device in which each coil and each core were not covered with a shield member was prepared as Comparative Example 1. FIG. Further, Comparative Example 2 was a power supply device in which the ends of the aluminum foil covering the coils and the cores were overlapped and contacted (conducted) without an insulator interposed therebetween. The turns ratio between the power feeding coil and the power receiving coil in each example is 50:9.

The measurement results are shown in FIGS. 13 and 14. FIG. FIG. 13 shows the relationship between leakage inductance and frequency, and FIG. 14 shows the relationship between magnetizing inductance and frequency.

As shown in FIG. 13, when the leakage inductance in the frequency range of 10000 to 100000 Hz is compared, it is found that the leakage inductance of the example is smaller than that of the comparative example 1. FIG. On the other hand, the example has a larger leakage inductance than the second comparative example.

Further, as shown in FIG. 14, when the excitation inductances are compared, the excitation inductance of the example is approximately the same as the excitation inductance of the first comparative example and is larger than the excitation inductance of the second comparative example. Although the leakage inductance of Comparative Example 2 is larger than that of the Example, the magnetizing inductance is greatly reduced, so it has been found that it is not suitable for highly efficient power transmission.

As described above, according to the embodiment, it is possible to reduce the leakage inductance while keeping the exciting inductance high.

1 power feeding device 11 power feeding coil 12 first core 13 power receiving coil 14 second core 15a first shield member 15b second shield member 15c third shield member (guide portion)
15d Fourth shield member (guide portion)
20 Conductor 20a Conductor first end 20b Conductor second end 21 Insulator

Claims (2)

a feed coil;
a receiving coil;
a first core around which the feeding coil is wound;
a second core around which the receiving coil is wound;
A power supply device comprising a shield member that covers the entire circumference of the power supply coil and the entire circumference of the power reception coil,
The shield member comprises a conductor and an insulator,
the conductor has a first end and a second end arranged to face each other;
The power supply device, wherein the insulator is arranged between the first end and the second end. 2. The power supply device according to claim 1, further comprising a guide portion for guiding said first core or said second core to a position where power can be supplied.

Images