JP2001110658A - Non-contact power supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-contact power supply device excellent in power supply ratio due to electromagnetic induction for a primary side and a secondary side. SOLUTION: The distance between the legs of a primary core 1a and a secondary core 1b is set more than twice the gap distance between both cores.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a power supply device for supplying electric power to electric equipment or the like in a non-contact manner by electromagnetic induction.

[0002]

2. Description of the Related Art Conventionally, for example, when an electric device such as a home electric appliance is used in a house, the electric power is supplied from an outlet installed on a wall or the like by using a power supply cord connected to the electric device. Was.

[0003] However, when power is supplied to an electric device using a power supply cord as described above, the range of use of the electric device is necessarily limited to a certain range where the power supply cord is limited. The power cord is always attached to, which is not only inconvenient for handling electrical equipment,
It was supposed to spoil the aesthetics of the room.

[0004] Further, when it is desired to use the electric equipment outdoors, it is necessary to draw out the power supply cord from indoors to outdoors.
For example, the windows must be left open, and there are various inconveniences such as insects entering the room in the summer and outdoor cold air flowing into the room in the winter. Further, the opened window may be closed as much as possible to prevent insects or outside air from entering, but in this case, the power supply cord may be damaged or disconnected by being caught between the window and the sash roll. was there.

Therefore, in order to solve the above-mentioned problem, the power transmitting coil and the power receiving coil are opposed to each other with a gap therebetween without using a power supply cord for supplying power to the electric device, and the power is transmitted in a non-contact manner by electromagnetic induction. A power supply was considered.

According to this power supply device, for example, even when an electric device is used outdoors, it is not necessary to open a window in order to draw out a power supply cord. By arranging a coil and a primary core around which the coil is wound, and arranging a secondary core around which the power receiving coil is wound outdoors in opposition to the primary core, electromagnetic induction is provided to the electric device connected to the power receiving coil. Power can be supplied.

Therefore, even when electric equipment is used outdoors, it is possible to supply electric power satisfactorily with the windows closed, and the problems caused by opening the windows are as follows:
That is, the invasion of insects and the inflow of outside air (cool air) can be reliably prevented.

[0008]

However, in the power supply device utilizing the electromagnetic induction, when the gap between the primary core and the secondary core (the width of a window glass or the like) increases, the magnetic resistance increases. The magnetic flux received on the receiving coil side decreases,
As a result, it has been very difficult to obtain sufficient power to operate the electric device connected to the receiving coil.

Accordingly, an object of the present invention is to solve such a problem and to provide a non-contact power supply device excellent in a power supply rate between a primary side and a secondary side by electromagnetic induction.

[0010]

According to the present invention, there is provided a non-contact power supply device in which a primary winding and a secondary winding of a coupling transformer can be individually separated, and a resonance capacitor is provided in the secondary winding. And the distance between the legs of the primary core and the secondary core respectively winding the primary winding and the secondary winding is twice or more the gap length existing between the primary core and the secondary core. Set.

The contactless power supply device of the present invention connects a resonance capacitor to the secondary winding of the coupling transformer,
The distance between the legs of the primary core and the secondary core that wind the primary winding and the secondary winding, respectively, is set to be at least twice the gap length existing between the primary core and the secondary core. By 1
The supply rate of power supplied from the secondary winding to the secondary winding by electromagnetic induction can be improved.

[0012]

FIG. 1 is a block diagram showing an embodiment of the present invention.
18 will be described. FIG. 1 is a schematic configuration diagram of a contactless power supply device of the present invention.
Reference numerals a and 1b denote a primary core and a secondary core constituting a coupling transformer. 2a and 2b are the primary core 1a and the secondary core 1b
A primary coil and a secondary coil are wound around the yoke portions 1c and 1d by a predetermined number of turns, respectively, and connected to power supply cords 4 and 5 connected to a power source and a load (light bulb in FIG. 1) 3, respectively.

The coupling transformer having the cores 1a and 1b and the coils 2a and 2b is divided into a primary side and a secondary side, respectively, and accommodated in a cover (not shown). 1 is used in a state where an obstacle such as a window glass is interposed in the gap 6) shown in FIG.

FIG. 2 shows a circuit configuration of the non-contact power feeding device. In the drawing, reference numeral 7 denotes an AC power supply, 8 denotes a rectifier diode bridge 8a and a smoothing capacitor 8b, and a rectifier for converting AC to DC. Circuit. Reference numeral 9 denotes an inverter for converting the output of the rectifier circuit 8 into AC again. The inverter 9 includes a switching element, a drive control circuit, and the like, and supplies high frequency power to the coupling transformer 10.

Reference numerals 2a and 2b denote a primary coil and a secondary coil which are wound around the primary core 1a and the secondary core 1b of the coupling transformer 10 by a predetermined number of turns, respectively.
A resonance capacitor 11 is attached to b in parallel with this, and a resonance circuit is formed by the secondary coil 2b and the capacitor 11. And the oscillation frequency on the primary side and 2
Both coils 2a, 2b are set so that the resonance frequencies on the secondary side become equal.
And the capacity of the capacitor 11 are set.

Reference numeral 3 denotes a load (light bulb or the like) to be controlled which is connected in series with the secondary coil 2b (in parallel with the capacitor 11). The load 3 is generated by high frequency power induced on the secondary side of the coupling transformer 10. The load 3 is controlled (lighted for a light bulb).

Subsequently, using the contactless power supply device,
A case where power is supplied (induced) to the secondary side will be described.
FIG. 3 shows, for example, between the primary core 1a and the secondary core 1b,
FIG. 3 is a diagram showing a power supply state when an obstacle 12 such as a window glass is present. When a current is supplied from a power supply 7 shown in FIG. 2 to a primary coil 2 a via a rectifier circuit 8 and an inverter 9, Magnetic flux is generated in the next coil 2a.

The magnetic flux generated in the primary coil 2a penetrates the obstacle 12 and interlinks with the secondary core 1b, but a part of the magnetic flux returns to the primary core 1a and is generated on the primary side. It is difficult for all the generated magnetic fluxes to link to the secondary side.

If the flux linkage to the secondary core 1b is small, the current induced in the secondary coil 2b naturally decreases, so it is necessary to supply sufficient power to the load 3 to drive it. Can not. This becomes more remarkable as the magnetic resistance of the obstacle 12 increases, that is, as the gap between the primary core 1a and the secondary core 1b increases.

Therefore, the contactless power feeding device of the present invention is shown in FIG.
As shown in FIG. 5, a resonance capacitor 11 is attached to the secondary core 1b in parallel with the secondary core 1b, and a resonance action is generated by the secondary coil 2b and the capacitor 11, thereby lowering the impedance on the secondary side. .

As a result, on the secondary side, apparently, only the winding resistance of the secondary coil 2b and the resistance of the load 3 are present, so that the current easily flows to the secondary side.
Power sufficient to drive and control the load 3 can be supplied to the secondary side.

The primary core 1a formed by the obstacle 12
If the gap between the and the secondary core 1b is constant, both cores 1
a, 1b, legs 1a ₁ and 1a ₂ , 1b ₁ , and 1
By increasing the b ₂ between distances, said to be larger than the magnetic resistance of the obstacle 12 a magnetic resistance in between the legs, to increase the flux of the chain交率passing from the primary core 1a to the secondary core 1b Can also.

FIG. 4 shows both cores 1a, 1b when the distance between the legs of both cores 1a, 1b is changed from 10 mm to 50 mm.
This is a graph in which the flux linkage rate between b is shown. In this graph, an air gap having a width of 10 mm exists between the cores 1a and 1b, and the cross-sectional area of the cores 1a and 1b is 100.
mm ² , the number of turns is 1, the current density applied to the primary coil 2 a is 1.00 × 10 ⁴ AT / m ² , and the current area is 140 mm ² .

As shown in FIG. 4, the flux linkage between the primary core 1a and the secondary core 1b increases with an increase in the distance between the legs.
The magnetic flux linked to the secondary core 1b maintains a substantially constant value regardless of the distance between the legs.

For example, when the distance between the legs of both cores 1a and 1b is 10 mm, 1.20E-6 is added to the secondary core 1b.
To generate a magnetic flux of about [T], both cores 1
Since the flux linkage ratio between a and 1b is about 30%, the primary coil 2a must be energized at a current value at which a magnetic flux of about 3.75E-6 [T] is generated in the primary core 1a. No. However, when the distance between the legs of the cores 1a and 1b is set to 50 mm and the same level of magnetic flux is generated in the secondary core 1b as described above, the flux linkage between the cores 1a and 1b is about 85%.
%, The primary coil 2a may be supplied with a current value at which a magnetic flux of 1.40E-6 [T] is generated in the primary core 1a.

That is, if the distance between the legs of both cores 1a and 1b is enlarged, necessary power can be supplied to the secondary side even if the magnetic flux generated in primary core 1a is small.

As a result, even if an excessive current is not applied to the primary coil 2a, the flux linkage between the primary core 1a and the secondary core 1b increases by increasing the distance between the legs,
The required electric power can be efficiently supplied to the secondary coil 2b. However, increasing the distance between the legs of the cores 1a and 1b increases the size of the device itself. Therefore, if the distance between the legs is set to the maximum while judging the allowable size of the device. Good.

FIGS. 5 to 9 show that the cross-sectional areas of both cores 1a and 1b are 50 mm ² , 150 mm ² and 200 m, respectively.
When set to m ² , 300 mm ² , 400 mm ² ,
It is a graph showing the magnetic flux linkage rate between both cores 1a and 1b in the state where the distance between the legs of both cores 1a and 1b was changed from 10 mm to 50 mm. The air gap, both cores 1
The number of turns a and 1b, the current density and the current area applied to the primary coil 2a are the same as those in the case of the graph shown in FIG.

As is clear from this graph, the flux linkage between the cores 1a and 1b tends to increase as the leg-to-leg distance increases regardless of the cross-sectional area of the cores 1a and 1b. You can see that.

Based on the graphs shown in FIGS.
The distance between the legs of the secondary core 1a and the secondary core 1b is 10 m, respectively.
m, 15mm, 20mm, 25mm, 30mm, 35m
m, 40mm, 45mm, 50mm
The cross-sectional area of both cores 1a and 1b is 50 mm ^{2 to} 400 mm ²
FIGS. 10 to 18 show the magnetic flux linkage between the two cores 1a and 1b when the values are changed up to the above.

From the graphs of FIGS. 10 to 18, when the distance between the legs of both cores 1a and 1b is 20 mm or more, regardless of the cross-sectional area of both cores 1a and 1b, the magnetic flux linkage between both cores 1a and 1b. The rate can always be maintained at 50% or more.
That is, if the distance between the legs is at least twice as large as the gap (in this case, 10 mm) between the primary core 1a and the secondary core 1b, the flux linkage rate of 50% or more can always be maintained.

As described above, by expanding the distance between the legs of the cores 1a and 1b, the flux linkage between the cores 1a and 1b can be improved. As a result, it is not necessary to supply a large current to the primary coil 2a in order to induce a sufficient current for driving and controlling the load 3 connected to the secondary side, and the switching elements and the like in the inverter 9 generate heat. As a result, the power supply efficiency between the primary side and the secondary side can be increased.

In this embodiment, as a simulation for obtaining the magnetic flux linkage between the primary side and the secondary side, the specifications of the apparatus described above (for example, a width of 10 mm between both cores 1a and 1b) are used.
mm air gap, the cross-sectional area of both cores 1a and 1b is 100 mm ² , the number of turns is 1 turn, and the primary coil 2a
The current density of 1.00 × 10 ⁴ AT / m ² , the current area of 140 mm ^2, etc.) has been described, but the present invention is not limited to the above specifications, and can be variously changed depending on the situation. Needless to say.

In the apparatus constructed by changing the above numerical values, the absolute value of the magnetic flux generated on the primary side and the secondary side changes, but the magnetic flux linkage rate which tends to increase with the expansion between the legs changes. Not surprisingly.

Further, in this embodiment, the cores 1a and 1b constituting the coupling transformer 10 have been described by taking the U-shaped core as shown in FIG. 1 as an example. Any shape may be used as long as the core structure can form the distance.

As described above, the contactless power supply device of the present invention
By setting the distance between the legs of the cores 1a and 1b to be at least twice the distance between the gaps between the cores 1a and 1b, the flux linkage rate can be increased and various losses can be reduced.

A capacitor 11 having a predetermined capacity is provided on the secondary side.
And by forming a resonance circuit with the secondary coil 2b and the capacitor 11, the impedance on the secondary side can be reduced and power transmission from the primary side to the secondary side can be performed efficiently.

[0038]

According to the non-contact power feeding device of the present invention, by forming a resonance circuit by connecting a resonance capacitor to the secondary side coil, the impedance of the secondary side can be easily lowered and the current can easily flow. did.

Further, the contactless power supply device of the present invention sets the distance between the legs of the primary core and the secondary core to be at least twice the distance between the gaps between the two cores, so that the magnetic flux linkage between the two cores is achieved. The rate is improved and various losses can be reduced, which is convenient.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a contactless power supply device of the present invention.

FIG. 2 is a circuit diagram of the wireless power supply device of the present invention.

FIG. 3 is a cross-sectional view illustrating an electromagnetic induction operation in the wireless power supply device of the present invention.

FIG. 4 is a graph showing the flux linkage between the two cores when the distance between the legs of the core is changed from 10 mm to 50 mm with the core cross-sectional area being 100 mm ² .

FIG. 5 is a graph showing the magnetic flux linkage between the two cores when the distance between the legs of the core is changed from 10 mm to 50 mm with the core cross-sectional area being 50 mm ² .

FIG. 6 is a graph showing the flux linkage between the two cores when the distance between the legs of the core is changed from 10 mm to 50 mm with the core cross-sectional area being 150 mm ² .

FIG. 7 is a graph showing the flux linkage between the two cores when the distance between the legs of the core is changed from 10 mm to 50 mm with the core cross-sectional area being 200 mm ² .

FIG. 8 is a graph showing the magnetic flux linkage between the two cores when the distance between the legs of the core is changed from 10 mm to 50 mm with the core cross-sectional area being 300 mm ² .

FIG. 9 is a graph showing the magnetic flux linkage between the cores when the distance between the legs of the core is changed from 10 mm to 50 mm with the core cross-sectional area being 400 mm ² .

Is a graph showing the flux-交率between both cores when the cross-sectional area of the core was varied from 50mm ² ~400mm ² in FIG. 10 while the inter-leg distance core 10 mm.

11 is a graph showing the flux-交率between both cores when the cross-sectional area of the core of the inter-leg distance while the 15mm cores were changed to 50mm ² ~400mm ^2.

12 is a graph showing the flux-交率between both cores when the cross-sectional area of the core of the inter-leg distance while the 20mm cores were changed to 50mm ² ~400mm ^2.

13 is a graph showing the flux-交率between both cores when the cross-sectional area of the core of the inter-leg distance while the 25mm cores were changed to 50mm ² ~400mm ^2.

14 is a graph showing the flux-交率between both cores when the cross-sectional area of the core of the inter-leg distance while the 30mm cores were changed to 50mm ² ~400mm ^2.

15 is a graph showing the flux-交率between both cores when the cross-sectional area of the core of the inter-leg distance while the 35mm cores were changed to 50mm ² ~400mm ^2.

16 is a graph showing the flux-交率between both cores when the cross-sectional area of the core of the inter-leg distance while the 40mm cores were changed to 50mm ² ~400mm ^2.

17 is a graph showing the flux-交率between both cores when the cross-sectional area of the core of the inter-leg distance while the 45mm cores were changed to 50mm ² ~400mm ^2.

18 is a graph showing the flux-交率between both cores when the cross-sectional area of the core of the inter-leg distance while the 50mm cores were changed to 50mm ² ~400mm ^2.

[Explanation of symbols]

 1a Primary core 1b Secondary core 2a Primary coil 2b Secondary coil 3 Load 6 Core gap 8 Rectifier circuit 9 Inverter 10 Coupling transformer 11 Resonant capacitor

Claims (1)

[Claims] A primary winding and a secondary winding of a coupling transformer can be individually separated. A capacitor for resonance is provided in the secondary winding, and the secondary winding is separated from the primary winding by a non-contact method. The distance between the legs of the primary core and the secondary core that wind the primary winding and the secondary winding, respectively, is set in the power supply device that supplies power to the windings. A non-contact power supply device characterized in that the gap length is set to be at least twice as long as the gap length.