JP2014204540A - Non-contact power supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-contact power supply device that can obtain relatively high power supply efficiency without requiring operation skills for power supply work under the installation space of a practical primary winding part and the power supply efficiency is stable.SOLUTION: A non-contact power supply device comprises a power reception unit 1 comprised in an electric vehicle X, and a power transmission unit 2 comprised in a power supply platform Y set on a road surface that enables the electric vehicle X to go and stop. The power reception unit 1 comprises a power reception winding part 4, and the power transmission unit 2 comprises a power transmission winding part 7 for exciting inductive electromotive force and attraction force at the power reception winding part 4. The power supply platform Y comprises a storage tank P for storing insulation fluid G. The power transmission winding part 7 comprises a buoyant source 9 for enabling the power transmission winding part 7 to move horizontally at a constant depth in the storage tank P.

Description

  The present invention relates to a non-contact power feeding device for charging a power supply device of an electric vehicle that uses electric power as energy for demonstrating the function of the vehicle, such as an electric vehicle and an electric wheelchair.

A non-contact power feeding device used for charging a power supply device of an electric vehicle generally includes a primary side (hereinafter referred to as power transmission) winding portion of a separation transformer in a power feeding platform, and a secondary side ( Hereinafter, this is referred to as “power reception.”) A configuration in which the winding portion is provided at the bottom of the electric vehicle is adopted.
In the separate transformer, if there is a positional deviation between the power transmission winding portion and the power receiving winding portion, the power feeding efficiency to the power receiving winding portion by the power transmission winding portion is lowered due to insufficient magnetic coupling. Conventionally, various measures have been taken to avoid such a situation.

  Specifically, a position detection device such as a position sensor is installed in the power transmission winding part or the power reception winding part, and both winding parts are within a certain range (for example, the positional deviation from the center of each winding part is ± 10 cm). A non-contact power feeding device (first conventional technology: see, for example, Patent Document 1 below) or a plurality of disk-type coils installed in the power transmission winding section. In addition, a non-contact power feeding device for mobile phones (second prior art) in which measures are taken to ensure good power feeding efficiency by energizing only the coil close to the place where the power receiving winding is placed, power transmission A method of detecting an appropriate positional relationship by providing a transmission side coil and a reception side coil in a winding part and a receiving winding part respectively and detecting the communication sensitivity of both (for example, Patent Document 2 below). And the like).

  Furthermore, in order to correct the positional deviation between the power transmission winding portion and the power receiving winding portion, a separate motor is attached, and the power transmission winding portion is moved so as to have a good positional relationship using the power. A technique (fourth conventional technique) or a technique (fifth conventional technique, for example, Patent Document 3 or Patent below) that automatically aligns by a magnetic force generated between a power transmission winding section and a power receiving winding section. The structure which combined literature 4 etc.) etc. is also introduced.

JP-A-63-48102 Japanese Patent No. 4772744 Japanese Patent Laid-Open No. 10-215532 JP 2009-95072 A

  However, in the first prior art and the third prior art, in order to quickly stop the electric vehicle so that the positional deviation from the predetermined position is within a certain range, the driver needs to be highly skilled. In adopting the second prior art, there is a problem that it is necessary to obtain a relatively large power transmission winding that can accommodate a large capacity power receiving winding portion such as a non-contact power feeding device for an electric vehicle. There is a problem that it is necessary to secure a space for installing a plurality of wire portions.

As in the fourth prior art, in the method of mechanically correcting the positional deviation using a driving means such as a motor, the driving device for moving the electric vehicle is enlarged, and the installation space is reduced. In addition to being difficult to ensure, there is a problem that separate maintenance and inspection of the drive device is required.
Further, as in the fifth prior art, in the technique of automatically pulling the floating power transmission winding portion to the power receiving winding portion by magnetic force to perform alignment, the strength of the magnetic force is maintained to a considerable extent. Otherwise, the position of the power transmission winding will be shifted by a relatively weak force such as the stress of the lead wire. Had the problem of unstable feeding efficiency.

  The present invention has been made in view of the above circumstances, and a relatively high power supply efficiency can be obtained without requiring skill in operation for power supply work under the installation space of a highly practical power transmission winding section, and An object of the present invention is to provide a non-contact power feeding device with stable power feeding efficiency.

  A non-contact power feeding device according to the present invention made to solve the above problems includes a power receiving unit provided in an electric vehicle and a power transmission unit provided in a power feeding platform set on a road surface on which the electric vehicle can pass and stop. The power receiving unit includes a power receiving winding unit, the power transmitting unit includes a power transmitting winding unit that excites induced electromotive force and attractive force in the power receiving winding unit, and the power feeding platform includes an insulating fluid. A storage tank is provided, and the power transmission winding section includes a buoyancy source that enables the power transmission winding section to move horizontally at a certain depth in the storage tank.

  The non-contact power feeding device may be a non-contact power feeding device including a braking unit that operates with an attractive force excited by the power transmission winding unit. The operation of the braking means may take either a form of braking with an attractive force excited by the power transmission winding part or a form of releasing the braking, and a structure in which the operation of the braking means differs depending on the strength of the attractive force. It may be adopted.

  The power receiving unit may include a power supply device having a power receiving winding unit with a polarity opposite to that of the power transmitting winding unit, thereby increasing the attractive force generated between the power transmitting unit and the power receiving unit.

  According to the non-contact power feeding device according to the present invention, when the primary winding (hereinafter referred to as a power transmission coil) is energized, the power transmission winding portion is brought close to the power reception winding portion by the magnetic force generated by the power transmission winding portion. In addition, it is possible to automatically perform positional deviation correction. Further, by suspending the power transmission winding part on the insulating fluid, the positional deviation correction can be performed without using a motor or the like even if the magnetic force is relatively weak. Thus, since the structure which makes the said power transmission winding part float on an insulating fluid can be implement | achieved by a comparatively simple structure, the expansion of the apparatus scale by the said structure addition and the increase in cost can be avoided.

When a power transmission winding section is in proximity to the power receiving winding section, a braking means that suppresses fluctuation of the power transmission winding section is provided so that both winding sections are fixed in an optimum positional relationship for non-contact power feeding, and power feeding efficiency Can be stably held in a high state.
Further, by adopting a configuration in which the braking means is operated by the attractive force excited by the power transmission winding portion, a sufficient braking means can be obtained at a low cost with a simple configuration without additionally providing an actuator.

  Further, by providing a power supply device that increases the conduction current of the power transmission winding section or supplies a secondary current having a polarity opposite to that of the power transmission coil to the secondary winding (hereinafter referred to as a power receiving coil). The allowable range of the positional deviation correction operation can be expanded or the operation can be stabilized, and an effect of avoiding the shaking after the positional deviation correction can be obtained.

FIG. 4A is a front view of a main part after correction of positional deviation, and FIG. 5B shows an example of a non-contact power feeding device according to the present invention. It is a side view after (A): position shift correction process and (B): position shift correction which show an example of the non-contact electric power feeder by this invention. It is a principal part front view at the time of achieving (A): position shift correction process and (B): position shift correction showing the state of magnetic flux in an example of the non-contact power feeding device according to the present invention. FIG. 4 is a front view of an essential part of an example of a braking means in the non-contact power feeding device according to the present invention, (A): during braking, (B): when braking is released, and (C): when braking is started. It is a circuit diagram in the electric power feeding mode and electromagnet mode which show an example of the non-contact electric power feeder by this invention. It is the top view, side view, and front view which show an example of the secondary winding part in the non-contact electric power feeder by this invention. It is the top view, side view, front view, and bottom view which show an example of the primary winding part in the non-contact electric power supply by this invention. It is a top view, a side view, and a front view of (A): a fixed part and (B): a movable part which show an example of the braking means of the non-contact electric power feeder by this invention. It is the top view, side view, front view, and bottom view which show an example of the primary winding part in the non-contact electric power supply by this invention.

Embodiments of a non-contact power feeding device according to the present invention will be described below with reference to the drawings.
The example shown in FIG. 2 is set on the road or in a parking space (these surfaces are used as road surfaces) so that the power receiving unit 1 included in the electric vehicle X and the electric vehicle X can be passed and stopped. The power supply platform Y includes the power transmission unit 2 (see FIG. 5).

In this example, the power receiving unit 1 includes a charger 3 that supplies power to the storage battery 16, a power receiving (secondary) parallel resonant capacitor C2, a power receiving winding portion 4 fixed to the bottom of the electric vehicle, and a power receiving circuit that requires these. A mode changeover switch SW2 that opens and closes is provided.
On the other hand, the power transmission unit 2 includes a three-phase 200V power source 5, an inverter power feeding device 6 that adjusts the power source 5 to a power source for power feeding, a power transmission winding unit 7, and a power transmission (primary) series resonance capacitor (primary capacitor) C1. And a mode changeover switch SW1 for short-circuiting the primary capacitor C1 (see FIG. 5).

The power transmission winding unit 7 constitutes a separation type transformer that excites induced electromotive force and attractive force in the power receiving winding unit 4. Here, the separation type transformer (hereinafter referred to as a transformer) is a transformer that uses the power transmission winding portion 7 and the power receiving winding portion 4 separately.
In the example, the power transmission winding portion 7 and the power receiving winding portion 4 transmit power to each of the cores 7a and 4a having a U-shape as if a rectangular core (a magnetic material such as ferrite or iron) was divided into two. The coil 7b and the power receiving coil 4b are wound.
The power transmission coil 7b is composed of a single coil or a plurality of coils (in the case of a plurality of coils, the number of coils and the number of windings of each coil are not limited). A circuit changeover switch (not shown) for switching the connections may be provided (see FIGS. 7 and 9).

The power feeding platform Y includes a storage tank P that stores the insulating fluid G, and the power transmission winding unit 7 is immersed in the storage tank P.
The power transmission winding unit 7 includes a buoyancy source 9 that allows the surface of the insulating fluid G to move horizontally at a certain depth in the storage tank P.
The insulating fluid G may be an insulating oil (mineral oil, vegetable oil, silicone oil, etc.) or the like.

The storage tank P has a size that can provide a sufficient correction range when aligning the power receiving winding portion 4 provided in the electric vehicle X and the power transmission winding portion 7 provided in the power feeding platform Y. The configuration is the same as when a container having a uniform depth is placed horizontally.
The filling amount of the insulating fluid G is such that when the lid S through which magnetic flux can pass is stored in the storage tank P, the power transmission winding portion 7 is as close as possible to the back surface of the lid S, and the power transmission winding. It is desirable that the amount of the line portion 7 can be freely moved without contacting the back surface of the lid S or the bottom surface of the storage tank P.

In this example, the power transmission winding portion 7 is fixed with a support frame 10 sandwiched between a float (buoyancy source) 9 that can float on the insulating fluid G.
A flexible and durable cable that does not hinder the free movement of the floating float 9 is selected for the lead wire 7c that supplies power to the power transmission winding section 7, and the shape and structure of the float 9 and the support frame 10 are as follows. It is desirable to select smooth ones that do not easily interfere with each other, such as the lead wire 7c being caught.

The support frame 10 in this example includes a rectangular plate portion 10a made of a non-magnetic material, and braking means 11 appropriately attached to the left and right end portions of the support frame 10 without losing balance (such as front-rear symmetry or left-right symmetry). Composed.
The float 9 is made of, for example, a non-magnetic material having an insulating property such as rubber or synthetic resin, for example, in a rectangular parallelepiped shape, and is symmetrical in the front-rear and left-right directions at the center of the back surface and the left and right side edges of the plate portion 10a. By adhering to the above, an appropriate buoyancy is given to the support frame 10 as described above, and the floating posture of the power transmission winding portion 7 is stabilized.

The braking means 11 includes a fixed portion 11a fixed to the plate portion 10a so as not to move and a movable portion 11b that can be moved up and down.
The fixed part 11a and the movable part 11b are both made of a magnetic material, and the restraining member 12 of the fixed part 11a and the core 7a of the power transmission winding part 7 cover a part of the upper part of the movable part 11b with a good balance. Therefore, the upper limit of the raising / lowering operation is regulated.
The shape of the restraining member 12 can be appropriately selected as long as a series of magnetic paths can be formed by the core 7a, the movable portion 11b, and the restraining member 12 (see, for example, FIG. 7 or FIG. 9). ).

The movable part 11b in the example includes a substantially flat table 14 having a square shape and a claw part 13 hanging from the center part of the back surface thereof, and the protrusions and recesses formed at the bottom of the storage tank P. (It may be irregularities formed on the surface of the sheet laid in a state of sinking to the bottom of the storage tank P.) By relating to D, the movement of the power transmission winding part 7 is restricted (braking), and the movable part The brake is released when 11b rises and the tip of the claw portion 13 is detached from the unevenness D (see FIG. 4).
Instead of the unevenness formed on the bottom of the storage tank P, a material or a structure that generates a frictional force sufficient for braking the transmission winding portion 7 between the lower end of the movable portion 11b may be adopted. .

  The movable part 11b regulates its ascending and descending orbits with guide holes 10b provided symmetrically on the left and right of the plate part 10a, and requires other driving means as follows by the magnetic force of the transmission winding part 7. Drive and control its movement.

<Electromagnet mode>
The power transmission winding unit 7 is connected to a circuit as shown in FIG. 5, for example, and a magnetic flux is generated by closing the mode changeover switch SW <b> 1 and passing a current through the power transmission coil 7 b of the power transmission winding unit 7. A magnetic path is formed by the core 7a, the movable portion 11b, and the fixed portion (restraining member 12) 11a (see FIG. 4A).
When the amount of current supplied to the power transmission coil 7b is increased, the magnetic force of the magnetic path formed by the power transmission winding portion 7 increases, and both side edges of the table (movable portion 11b) 14 are connected to the stop member 12. As shown in FIG. 4 (B), the core 7a is pulled up and brought into contact with the core 7a.

  On the other hand, as shown in FIG. 9, when a plurality of power transmission coils 7b are provided, a method of switching the plurality of power transmission coils 7b to series connection and increasing the magnetic force of the magnetic path by the circuit changeover switch can be adopted. . In particular, when a plurality of power transmission coils 7b having different numbers of turns are provided, a method is employed in which the circuit changeover switch supplies a current to the power transmission coil 7b having a larger number of turns to increase the magnetic force of the magnetic path as described above. You can also.

  The power transmission winding portion 7 floating in the insulating fluid G is received by the electric vehicle X when the magnetic flux enters the core 4a of the power reception winding portion 4 from the core 7a of the power transmission winding portion 7. It is attracted to the winding part 4 and moves (see FIG. 3).

At this time, the power supply at the time of correcting the misalignment is prohibited, and as a result, the mode selector switch SW2 is opened to receive power from the power receiving winding unit 4 in order to prevent damage to the circuit (rectifier, charger 3, etc.) of the power receiving unit 1. It is desirable to cut off the coil 4b from the circuit leading to the charger 3.
Further, if a current having a polarity opposite to that of the power receiving winding portion 4 is supplied from another exciting storage battery (not shown) to the power receiving winding portion 4, a stronger magnetic force for correcting the misalignment can be obtained. In some cases, the allowable range, accuracy, and stability of positional deviation correction can be improved.

<Power supply mode>
In the power feeding mode, the power transmission winding unit 7 and the power receiving winding unit 4 constitute the transformer, and the power generated by the inverter power feeding device 6 is supplied to the storage battery 16 through the charger 3.

  When it is detected that the power transmission winding portion 7 has moved within an allowable range substantially below the power receiving winding portion 4, the mode changeover switch SW1 is opened and SW2 is closed to switch to the power supply mode (see FIG. 5). ).

On the other hand, as shown in FIG. 9, when a plurality of power transmission coils 7b are provided, the power transmission series resonance capacitor C1 and the power transmission coil 7b are switched by switching the plurality of power transmission coils 7b to parallel connection by the circuit switch. It is possible to adopt a method of supplying power by making the resonance frequency coincide with the operation frequency of the inverter power supply device 6.
In particular, when a plurality of power transmission coils 7b having different numbers of turns are provided, the number of turns is set so that the resonance frequency by the power transmission coil 7b having a small number of turns and the power transmission series resonance capacitor C1 matches the operation frequency of the inverter power supply device 6. In addition, it is also possible to use a method of supplying power by switching from the power transmission coil 7b having a large number of turns to the power transmission coil 7b having a small number of turns by the circuit changeover switch.

  At this time, the current supplied to the power transmission winding portion 7 and the magnetic force generated thereby are reduced as compared with the electromagnet mode, so that the ascending portion of the table 14 is not maintained in the storage tank P without being able to maintain the rise of the table 14. The weight is lowered until reaching the bottom, and the movement of the power transmission winding portion 7 is stopped at the position deviation correction end position immediately before the shift to the power feeding mode (see FIG. 4C).

The raising / lowering state of the movable portion 11b may be adjusted by a method of adjusting the threshold value when shifting to each mode with magnetic force in light of the weight or balance between buoyancy and magnetic force, If the table 14 is too heavy to be raised by magnetic force, the table 14 can be adjusted by attaching a float 9 as a buoyancy source, and if it is too light, placing a weight 15 on the table 14. .
As a method for detecting that the power transmission winding portion 7 has moved within an allowable range almost directly below the power receiving winding portion 4, a method of regulation including the conventional method may be appropriately selected.

In the electromagnet mode, the current supplied to the power transmission coil 7b and the power receiving coil 4b is maintained by the magnetic force generated between the two winding portions 7 and 4, and the power transmission winding portion 7 is pulled up. Is not large enough.
The mode of the current supplied to the power transmission coil 7b may be a direct current or a pulse current, and the current supplied by the inverter power supply device 6 may be changed. As in this example, the primary capacitor C1 is You may adjust so that the magnetism suitable for an electromagnet mode may be generate | occur | produced by closing mode switching switch SW1 and short-circuiting and pulling down an operating frequency to several Hz-several kHz.

C1 power transmission (primary) series resonance capacitor, C2 power reception (secondary) parallel resonance capacitor,
D unevenness, G insulating fluid, P reservoir, S lid,
X electric vehicle, Y power supply platform,
1 power receiving unit, 2 power transmitting unit, 3 charger,
4 power receiving (secondary) winding, 4a core, 4b power receiving coil, 4c lead wire,
5 power supply, 6 inverter power supply device,
7 power transmission (primary) winding part, 7a core, 7b power transmission coil, 7c lead wire,
9 Buoyancy source (float),
10 support frame, 10a plate part, 10b guide hole,
11 braking means, 11a fixed part, 11b movable part,
12 stop member, 13 claw part, 14 table, 15 weight, 16 storage battery,

Claims (3)

A power receiving unit provided in the electric vehicle, and a power transmission unit provided in a power supply platform set on a road surface on which the electric vehicle can pass and stop,
The power receiving unit includes a power receiving winding unit,
The power transmission unit includes a power transmission winding unit that excites induced electromotive force and attractive force in the power receiving winding unit,
The power supply platform includes a storage tank for storing an insulating fluid,
The non-contact power feeding apparatus, wherein the power transmission winding unit includes a buoyancy source that enables the power transmission winding unit to move horizontally at a certain depth in the storage tank.   The contactless power feeding device according to claim 1, further comprising a braking unit that operates with an attractive force excited by the power transmission winding unit.   The non-contact power feeding device according to claim 1, wherein the power receiving unit includes a power supply device having a power receiving winding unit with a polarity opposite to that of the power transmitting winding unit.

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