JP5534889B2 - Non-contact power feeding system and driving method thereof - Google Patents

Description

  The present invention relates to a non-contact power feeding system and a driving method thereof.

  In recent years, with the advancement of power devices, applied products have become a reality, and there is a demand for flexibility in the supply of electric power to electric products used by people. As a power supply system that meets this demand, contactless power supply technology has been developed in a wide range of fields. For example, by using a non-contact power feeding method for power feeding to a moving body used in a factory transport line, safe and clean power transmission without sparks and dust can be achieved. In addition, there are no physical consumable parts, and it is attracting attention as an extremely effective system.

  The contact-type power supply device supplies power to a moving body by sliding a movable contact connected to a load (moving body, that is, a power supply target), on a fixed contact on a rail connected to a power source. For this reason, in the contact-type power supply device, leakage from the fixed contact, poor contact between the contacts, or the like occurs. On the other hand, in the non-contact power feeding device, an induced voltage is generated between the primary side connected to the power source side and the secondary side connected to the load side. Since there is no contact on the secondary side, there are no problems such as leakage and poor contact which are problems in this contact-type power feeding device.

  As shown in FIG. 9, an example of such a non-contact power feeding device is a power supply line 120 connected to a high frequency power supply 110 and supplied with an alternating current having a high frequency, and a displacement not shown along the power supply line 120. And a power receiving unit 200 electrically connected to a load Z of the moving body. The power receiving unit 200 is formed by a coil 3 through which an induced current flows by electromagnetic induction based on a high-frequency current flowing through the feeder 120, an arm unit around which the coil 3 is wound, and a connecting unit that connects the arm unit. Core 2.

  Then, the core 2 is installed so as to surround the outer periphery of the power supply line 120 with the arm part and the connecting part, so that the direction of the magnetic field on the outer peripheral side of the power supply line 120 generated when a high-frequency current (for example, 10 kHz) flows. A magnetic circuit by the core is formed along the line. Thus, the magnetic circuit by a core is formed in the outer periphery of the feeder 120, and the magnetic flux generated on the outer periphery of the feeder 120 is converged in the core.

Therefore, an electric current is induced in the coil 3 wound around the arm portion of the core 2 and is supplied to a load such as a driving device 300 including a motor or a control circuit of a moving body (not shown). At this time, the current generated in the coil 3 is converted into power by a power conversion circuit provided on the load side and then supplied to the load Z, so that stable power is supplied to the load. In the non-contact power feeding device configured as described above, in the power receiving unit 200 that performs a power receiving operation by electromagnetic induction based on the high-frequency current flowing through the power supply line 120, there are various types of the core and the coil 3 in order to increase power receiving efficiency The design is made.
In such a non-contact power feeding apparatus, the load circuit employs a series resonance circuit as shown in FIG. 10 in order to improve transmission efficiency. The power supply line is an electric wire and includes an inductance component L and a resistance component R. Thus, by adding a resonant capacitor C _0, to an inductance L and the resonance circuit of the power supply line (Non-Patent Document 1).
In the non-contact power supply device, the inductance component and resistance component of the power supply line also change depending on the length of the power supply line and the state of the load. For this reason, when manufacturing the non-contact power supply device, the current component and the voltage component flowing through the power supply line are measured, a resonance capacitor is added, and the power factor is adjusted to be close to unity. “The power factor is 1” means that when the inductance component of the feeder line is L and the capacitance of the resonance capacitor is C ₀ , the resonance frequency f is
ωL−1 / ωC ₀ ≒ 0 (Formula 1)
It is to be.
For example, a pair of U-shaped pickups that are paired with the forward and return paths of the feeder line so that one leg overlaps in one direction to reduce the center-to-center distance between the forward and return paths of the feeder line. In addition, a non-contact power feeding device that reduces inductance and increases power feeding efficiency has also been proposed (Patent Document 1).

JP 2003-61268 A

Shimada Rika Technical Report No.20 (2008) P47-50 Inverter for contactless power feeding

In order to increase the power factor, a configuration for reducing the distance between the centers of the forward path and the return path of the feeder line and reducing the inductance is proposed as in the non-contact power feeder shown in Patent Document 1. In order to achieve the resonance frequency, determination and mounting of the capacity of the resonance capacitor requires a high degree of skill and causes a decrease in workability.
In addition, with the increase in use time, it is not possible to avoid the secular change of the feeder line and the fluctuation of the load. For this reason, there has been a problem that there is no countermeasure against changes in the inductance component and the resistance component of the feeder line itself, and a reduction in power factor cannot be avoided.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a non-contact power feeding system that is easy to handle and has a high power factor, and a driving method thereof.

Therefore, the non-contact power feeding system of the present invention includes a high-frequency power source, a power feeding unit including a power feeding line connected in series to the high-frequency power source, and a power receiving unit installed in a non-contact manner on the outer periphery of the power feeding line, The power receiving unit supplies the power received by electromagnetic induction with the power supply line to the load connected to the power receiving unit, and the power supply unit automatically varies the resonance element whose reactance component can be increased and decreased and the parameters of the resonance element A resonance adjustment unit that performs resonance adjustment, and the power supply line includes a cylindrical inner pipe part, a cylindrical outer pipe part arranged outside the inner pipe part, the inner pipe part, and the The present invention is characterized in that a conductor formed by a connecting portion that connects the outer tube portions so as to be concentric with each other is covered with an insulator made of a synthetic resin molded product having a rectangular tube shape .
Further, the present invention is characterized in that in the above non-contact power feeding system, the resonance adjustment unit is configured to perform resonance adjustment after driving for a predetermined time.
According to the present invention, in the contactless power supply system, the resonance adjustment unit includes a measurement unit that measures the difference between the voltage (V _L ) between the wires connected to the high-frequency power source and the voltage across the resonance element (V _C ). And the resonance element parameter is controlled so that the difference becomes a predetermined value .
Or the present invention, in the contactless power supply system, the resonant element, characterized in that it is a variable capacitor.
In the wireless power supply system according to the present invention, the resonance adjustment unit includes a monitor unit that monitors a voltage-current phase of the high-frequency power source, and adjusts the resonance element so that the phase difference becomes a desired value. And
According to the present invention, in the contactless power supply system, the resonance element is a capacitor configured such that the distance between the electrodes can be changed, and the resonance adjustment unit adjusts the distance between the electrodes according to the output of the monitor unit. And
In the wireless power supply system according to the present invention, the variable capacitor includes a plurality of electrodes, and the capacitance is changed by selecting two of the electrodes.
The driving method of the non-contact power feeding system of the present invention includes a high frequency power source, a power feeding line connected in series to the high frequency power source, a power feeding unit, and a power receiving unit installed in a non-contact manner on the outer periphery of the power feeding line. A method of driving a non-contact power feeding system in which a power receiving unit receives power received by electromagnetic induction with a power feeding line to a load connected to the power receiving unit. The process of supplying the power received by electromagnetic induction to the load connected to the power receiving unit, the process of measuring the reactance component of the feeder line, and automatically changing the parameters of the resonance element according to the magnitude of the reactance component look including a resonance adjustment step, the feed line, together with the inner tubular part of the cylindrical, and the outer tube portion of the arranged cylindrical outside of the inner tube portion, the outer tube portion and the inner tube portion A connecting part that connects concentrically and The configured conductors are constructed by coating an insulator made of rectangular tube-like synthetic resin molded product.

  According to the present invention, since the resonant element whose reactance component can be easily changed is automatically variable, the power factor can be improved with extremely good workability, and the power transmission from the power supply line to the power receiving unit can be improved. Efficiency can be improved.

Schematic diagram of the non-contact power feeding system of Embodiment 1 of the present invention FIG. 3 is an equivalent circuit diagram of the contactless power feeding system according to the first embodiment of the present invention. Explanatory drawing which shows an example of the output of the monitor apparatus in the non-contact electric power feeding system of Embodiment 1 of this invention It is a figure which shows an example of the variable capacitor used with the non-contact electric power feeding system of Embodiment 1 of this invention, (a), (b) is a figure which shows the electrode selection state of each state Sectional drawing of the feeder of the non-contact electric power feeding system of Embodiment 1 of this invention Sectional drawing of the pick-up part of the non-contact electric power feeding system of Embodiment 1 of this invention Explanatory drawing which shows the equivalent circuit schematic of the adjustment method using the non-contact electric power feeding system of Embodiment 2 of this invention Explanatory drawing which shows the equivalent circuit schematic of the adjustment method using the non-contact electric power feeding system of Embodiment 3 of this invention Overview of conventional contactless power supply system Equivalent circuit diagram of conventional contactless power supply system

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a schematic diagram showing a non-contact power supply system according to Embodiment 1 of the present invention. FIG. 2 is an equivalent circuit diagram of the non-contact power feeding system, and FIG. 3 is an explanatory diagram illustrating an example of an output of the monitor device in the non-contact power feeding system. FIG. 4 is a view showing an example of a variable capacitor used in the non-contact power feeding system, and FIGS. 4A and 4B show electrode selection states in each state. FIG. 5 is a cross-sectional view of the power supply line, and FIG. 6 is a cross-sectional view of the pickup portion of the power supply apparatus.

  As shown in the schematic diagram of FIG. 1 and the equivalent circuit diagram of FIG. 2, the non-contact power feeding system of the first embodiment is provided with a variable capacitor 140 as a resonance element capable of increasing or decreasing the reactance component, and automatically adjusts the capacitance. The feature is that it can be realized. This is because the voltage phase and current phase of the high-frequency power supply 110 are monitored by the monitor unit 130, and as shown in FIG. 3, the resonance adjustment unit 150 adjusts the obtained phase difference G to a desired value. Resonance adjustment is performed by automatically varying the variable capacitor 140.

That is, the resonance adjustment unit 150 adjusts the capacitance C of the variable capacitor 140 from the current component and the voltage component flowing through the power supply line 120 of the non-contact power supply system so that the power factor is adjusted to be close to unity. In other words, “the power factor is 1” means that the inductance component of the feeder line is L and the capacitance of the variable capacitor is C, with respect to the resonance frequency f, as in the above-described equation (1).
ωL-1 / ωC ≒ 0 (Formula 2)
Is true.
Therefore, adjustment is performed so that C≈1 / ω ² L.

  The monitor unit 130 monitors the voltage phase and the current phase using a current measuring device such as a CT and a voltage measuring device, and the resonance adjusting unit 150 determines the capacitance C so as to satisfy the above equation 2. For example, in current measurement or voltage measurement, a current sensor or a power sensor using a magnetic thin film can be appropriately selected and used.

  That is, this non-contact power feeding system includes a power feeding unit 100 including a high-frequency power source 110, a power feeding line 120 connected in series to the high-frequency power source 110, and a power receiving unit 200 installed in a non-contact manner on the outer periphery of the power feeding line. The power receiving unit 200 supplies the power received by electromagnetic induction with the power supply line 120 to a load such as the driving device 300 connected to the power receiving unit 200.

  Actually, the resonance adjustment unit 150 can be operated at predetermined time intervals, and the resonance adjustment can be performed after driving for a predetermined time, so that adjustment corresponding to a change with time can be performed. That is, the capacitance C of the variable capacitor is adjusted so as to correspond to the resonance frequency f in consideration of the state of the entire system on the power receiving unit side in accordance with the load condition and the like.

  Due to the inductance component of the feeder 120, the current phase I is delayed by G from the voltage phase V as shown in FIG. The capacitance C of the variable capacitor is adjusted so as to minimize this delay. That is, by making the current phase I as close as possible to the voltage phase V, the power factor becomes approximately 1.

  The variable capacitor 140 is composed of a fixed electrode 131 and a moving electrode 133, and is selected by an actuator (not shown) so that the moving side terminal Tm is connected to an electrode at a desired position so that the fixed side terminal Ts is connected. The distance between the electrodes connected to the fixed electrode 131 is variable and is set to have a desired capacitance value. For example, as shown in FIG. 4A, the moving electrode 133 is located on the side farther from the fixed electrode 131 as shown in FIG. 4B than when the electrode piece 133a closer to the fixed electrode 131 is selected. When the electrode piece 133b is selected, the distance between the electrodes is increased and the capacity is increased. In this way, the moving electrode 133 is selected by the actuator, and the capacitance becomes variable.

  Here, a power receiving unit 200 that supplies power to a motor as the driving device 300 is provided. The power receiving unit 200 includes a power supply line 120 through which a high-frequency current flows and a pickup unit 1 including the core 2 that is inductively coupled to the power supply line 120, and the induced electromotive force induced in the pickup unit 1 By supplying power to the driving device 300, a load (not shown) is driven. The power supply line 120 is fixed to a wall by a jig (not shown), and power is received while the pickup unit 1 moves along the power supply line 120. Except for providing the variable capacitor 140 as described above, the configuration is the same as that of a typical non-contact power feeding system.

  As shown in FIG. 5, the feeder 120 includes a cylindrical inner tube portion 101, a cylindrical outer tube portion 102 disposed outside the inner tube portion 101, and the inner tube portion 101 and the outer tube portion 102. A conductor constituted by four connecting portions 103 connected so as to be concentric with each other is covered with an insulator 104 made of a synthetic resin molded product having a rectangular tube shape. Note that the feeder line is not necessarily limited to this structure, and the manufacturing method is not limited to the method of press-fitting the inner tube portion 101 having the connecting portion 103 into the outer tube portion 102, or bending or It can also be manufactured by metal extrusion. By using a double-pipe structure conductor for the feeder line 120 in this way, it is possible to reduce high-frequency resistance and loss compared to a cylindrical conductor, but in a feeder line through which a high-frequency current flows, In addition to the electrical resistance of the conductor material (metal plate), there are slight resistance components (high frequency resistance) and inductance components due to the skin effect and proximity effect. The capacitance value of the variable capacitor is changed according to the change in the surrounding situation, including the change in the resistance component and the inductance component due to the power supply line 120.

  Here, the power receiving unit 200 includes the pickup unit 1 and the power receiving circuit unit 6. As shown in detail in FIG. 6, the pickup unit 1 includes a core 2, a coil 3, a bobbin 4, and a magnetic shield body 5 (power receiving circuit unit 6). The power receiving circuit unit 6 includes a capacitor that forms a resonance circuit together with the coil 3, a constant voltage circuit that makes the resonance voltage output from the resonance circuit of the coil 3 and the capacitor constant, and the like.

  Further, as shown in FIG. 6, the core 2 has both an inner peripheral surface and an outer peripheral surface formed of curved surfaces (cylindrical surfaces), and a cross-sectional shape that intersects the axial direction (perpendicular to the paper surface) has a substantially C shape. Has been. Here, both end portions 20 of the core 2 facing each other with the opening groove 2a interposed therebetween are cross sections along the axial direction, rather than portions (hereinafter referred to as “body portions”) 21 excluding the both end portions 20 of the core 2. The area is formed large.

  Further, the bobbin 4 is formed of a cylindrical resin molded product curved in an arc shape, and outer casings 40 are provided at both ends in the axial direction. The core 2 is divided into two body parts 21 at the opposite side of the opening groove 2a, and the end parts of the body part 21 are joined to each other after the bobbin 4 is extrapolated to each body part 21. Thus, the core 2 shown in FIG. 6 is configured. The coil 3 is formed by winding a winding having an insulating coating around the bobbin 4 in a single layer.

  The magnetic shield body 5 is formed in a substantially cylindrical shape by a metal magnetic material having a high magnetic permeability, and is extrapolated to the core 2 and the coil 3. However, the magnetic shield body 5 is provided with a groove 5a communicating with the opening groove 2a of the core 2 along the axial direction. The magnetic shield 5 is not essential and may be omitted.

As shown in FIG. 1, the core 2 has a substantially U-shaped outer section so as to straddle the power supply line 120 from the side, and the core 2 is located on both sides of the power supply line 120 inside the outer structure. A pair of coils are arranged opposite to each other to constitute an electromagnetic pickup. Here, the coil is preferably as close as possible to the feeder 120. Then, when a high-frequency current is supplied from the high-frequency power source 110 to the power supply line 120, a magnetic field MF is generated and attenuated according to the frequency of the supplied high-frequency current around the power supply line 120. Becomes a change in magnetic flux density, and an induced current is generated in the coil (electromagnetic induction).
In the power receiving circuit unit 6 shown in FIG. 1, the current generated in the coil in this way is stabilized by a resonance circuit (not shown) and then sent to the load.
As described above, the inductance component and the resistance component of the feeder 120 may change depending on the state of the load including the power receiving unit 200 including the power receiving circuit unit 6 and the driving device 300. Adjust the volume with the adjustment unit.

As described above, according to the contactless power supply system of the present embodiment, it is possible to realize contactless power supply with a high power factor very easily. In addition, since the actual adjustment can be automatically performed at the site of use, fine adjustment is possible and the power factor can be improved.
Furthermore, when the length or state of the power supply line is changed or the load state is changed during installation or use, adjustment on the site is facilitated.
In this way, power can be supplied without the sliding portion, and by supplying power to the driving device by the induced electromotive force induced in the pickup portion 1, the load is driven, no wear powder is generated, and in a clean environment. Maintenance frequency can be reduced.

  In the above embodiment, the variable capacitor is used. However, the present invention is not limited to this, and it goes without saying that another variable capacitor generating circuit such as a varicap may be used.

(Embodiment 2)
In the first embodiment, the current phase is monitored and the method of adjusting the phase difference to zero is adopted. In the present embodiment, the voltage between the feeder lines 120 connected to the high frequency power supply 110 ( The difference between V _L ) and the voltage (V _C ) across the variable capacitor 140, which is a resonance element, is measured, and the capacitance is adjusted according to this difference.

That is, as shown in FIG. 7, the resonance adjustment unit 150 calculates a voltage (V _L ) between the power supply lines 120 connected to the high frequency power supply 110 and a voltage (V _C ) across the variable capacitor 140 that is a resonance element. A measuring unit for measuring the difference is provided. Here, the voltage _VL between the feeder lines 120 is measured by a voltmeter in the vicinity of the high-frequency power source 110. Then, the voltage difference V _L -V _C obtained by this measurement unit is guided to the monitor unit and output, and the capacitance value (parameter) of the variable capacitor 140 is set so that this difference becomes a predetermined value (α). Control. Here, α is a system-fixed constant.
V _L −V _C = α (Formula 3)

  Even in this method, in practice, the resonance adjustment unit 150 is operated every predetermined time, and the resonance adjustment is performed after the predetermined time drive so that the adjustment corresponding to the change with time can be performed. Can do. The capacity of the variable capacitor 140 can be adjusted so as to have a resonance frequency close to the resonance frequency f in consideration of the state of the entire system on the power receiving unit side in accordance with the load condition and the like.

(Embodiment 3)
In the first embodiment, the current phase is monitored and the method of adjusting the phase difference to zero is adopted, whereas in the present embodiment, the output voltage (Vout) of the high frequency power supply 110 is measured, and this The capacitance of the variable capacitor is adjusted while monitoring the measured value.
That is, as shown in the explanatory diagram of FIG. 8, in the resonance adjustment unit (150), the resonance element (150) is minimized so that the output voltage (Vout) of the high-frequency power supply does not become smaller than a predetermined voltage β. Control the parameters of the variable capacitor.
In other words, the output voltage (Vout) of the high frequency power supply is Vout> β (Equation 4)

  Also in this method, as with the first and second embodiments, in practice, the resonance adjustment unit (150) is operated every predetermined time, and the resonance adjustment is performed after driving for a predetermined time. It can be configured to be able to adjust in accordance with The capacity of the variable capacitor can be adjusted so as to have a resonance frequency close to the resonance frequency f in consideration of the state of the entire system on the power reception unit side in accordance with the load condition and the like.

  In the above embodiment, the capacitance is adjusted using the variable capacitor. However, the resonance element such as a coil that can adjust the reactance component may be changed without being limited to the capacitance.

  In addition, although this invention was demonstrated taking the said each embodiment as an example, various other embodiment can be employ | adopted in the range which is not restricted to these embodiments and does not deviate from the summary of this invention.

DESCRIPTION OF SYMBOLS 1 Pickup part 2 Core 3 Coil 100 Feeding part 101 Inner pipe part 102 Outer pipe part 103 Connection part 104 Insulator 110 High frequency power supply 120 Feed line 130 Monitor part 140 Variable capacity capacitor 150 Resonance adjustment part 200 Power receiving part 300 Drive device

Claims (8)

A power supply unit comprising a high-frequency power supply and a power supply line connected in series to the high-frequency power supply;
A power receiving unit installed in a non-contact manner on the outer periphery of the feeder line;
A non-contact power feeding system that supplies power received by the power receiving unit by electromagnetic induction with the power feeding line to a load connected to the power receiving unit,
The power supply unit includes a resonance element that can increase or decrease its reactance component, and a resonance adjustment unit that performs resonance adjustment by automatically changing a parameter of the resonance element ,
The power supply line includes a cylindrical inner tube portion, a cylindrical outer tube portion disposed outside the inner tube portion, and a connection that connects the inner tube portion and the outer tube portion so as to be concentric with each other. A non-contact power feeding system configured by covering a conductor configured with a portion with an insulator made of a synthetic resin molded product having a rectangular tube shape . The contactless power supply system according to claim 1,
The resonance adjustment unit is a non-contact power feeding system configured to be able to perform resonance adjustment after driving for a predetermined time. It is a non-contact electric power feeding system according to claim 1 or 2,
The resonance adjustment unit includes a measurement unit that measures a difference between a voltage (VL) between electric wires connected to the high-frequency power source and a voltage across the resonance element (VC),
A non-contact power feeding system configured to control a parameter of the resonance element so that the difference becomes a predetermined value. It is a non-contact electric supply system according to any one of claims 1 to 3 ,
The resonance element is a non-contact power feeding system which is a variable capacitor. It is a non-contact electric supply system according to any one of claims 1 to 3 ,
The resonance adjustment unit includes a monitor unit that monitors a voltage-current phase of the high-frequency power source,
A non-contact power feeding system that adjusts the resonance element so that the phase difference becomes a desired value. The contactless power supply system according to claim 5 ,
The resonance element is a variable capacitor configured such that a distance between electrodes can be changed, and the resonance adjustment unit adjusts the distance between the electrodes in accordance with an output of the monitor unit. The contactless power supply system according to claim 4 or 6 ,
The variable capacitance capacitor includes a plurality of electrodes, and the capacitance is changed by selecting two from the electrodes. A high-frequency power supply, a power supply line connected in series to the high-frequency power supply, a power supply unit, and a power reception unit installed in a non-contact manner on the outer periphery of the power supply line,
A method of driving a non-contact power supply system that supplies power received by the power receiving unit by electromagnetic induction with the power supply line to a load connected to the power receiving unit,
Passing a current from the high-frequency power source to the power supply line and supplying power received by electromagnetic induction with the power supply line to a load connected to the power receiving unit;
Measuring a reactance component of the feeder line;
Depending on the magnitude of the reactance component, seen including a resonance adjustment step of automatically varying the parameters of the resonant element,
The power supply line includes a cylindrical inner tube portion, a cylindrical outer tube portion disposed outside the inner tube portion, and a connection that connects the inner tube portion and the outer tube portion so as to be concentric with each other. A driving method of a non-contact power feeding system configured by covering a conductor constituted by a portion with an insulator made of a synthetic resin molded product having a rectangular tube shape .

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