JP2014017893A - Non-contact power transmission device - Google Patents

Non-contact power transmission device Download PDF

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Publication number
JP2014017893A
JP2014017893A JP2012151568A JP2012151568A JP2014017893A JP 2014017893 A JP2014017893 A JP 2014017893A JP 2012151568 A JP2012151568 A JP 2012151568A JP 2012151568 A JP2012151568 A JP 2012151568A JP 2014017893 A JP2014017893 A JP 2014017893A
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Japan
Prior art keywords
frequency
power
resonance
voltage source
ac voltage
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Pending
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JP2012151568A
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Japanese (ja)
Inventor
Hiroshi Katsunaga
浩史 勝永
Yuichi Taguchi
雄一 田口
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Toyota Industries Corp
株式会社豊田自動織機
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Priority to JP2012151568A priority Critical patent/JP2014017893A/en
Publication of JP2014017893A publication Critical patent/JP2014017893A/en
Application status is Pending legal-status Critical

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Abstract

PROBLEM TO BE SOLVED: To provide a non-contact power transmission device capable of suitably supplying electric power from an AC voltage source to a load even when a load impedance varies.SOLUTION: A controller 22 adjusts so that a resonance frequency of a resonance system and a frequency of AC power output from an AC voltage source approaches each other when a load impedance varies. The controller 22 and a constant variable circuit 15 changes a capacitance value of a capacitor so that a power factor is improved in a state adjusted to bring the resonance frequency of the resonance system near the frequency of AC power output from the AC voltage source.

Description

  The present invention relates to a non-contact power transmission apparatus.

  In the non-contact power transmission device described in Patent Document 1, the state of the resonance system (primary coil, primary side resonance coil, secondary side resonance coil, secondary coil, load) is detected, and based on the detection result. In the variable impedance circuit, the impedance is adjusted so that the input impedance at the resonance frequency of the resonance system matches the impedance on the high frequency power supply side from the primary coil.

JP 2010-141976 A

By the way, since the resonance frequency of the resonance system changes due to fluctuations in the impedance of the load, there is a case where it is not possible to suitably transmit electric power with the output frequency fixed.
An object of the present invention is to provide a non-contact power transmission apparatus that can suitably supply power from an AC voltage source to a load even when the impedance of the load fluctuates.

  In the first aspect of the present invention, an AC voltage source, a primary-side resonator that receives power from the AC voltage source, a secondary-side resonator that receives power from the primary-side resonator, A non-contact power transmission device comprising a load to which power received by the secondary resonator is supplied, and comprising a resonance system by at least the primary resonator, the secondary resonator, and the load. A frequency adjusting means for adjusting the resonance frequency of the resonance system and the frequency of the AC power output from the AC voltage source when the impedance of the load fluctuates, and at least one of a capacitor or an inductor. Then, the frequency adjustment means adjusts the power factor so that the power factor is improved in a state where the resonance frequency of the resonance system and the frequency of the AC power output from the AC voltage source are adjusted to approach each other. A constant changing means for changing at least one of the capacitance value or inductance value of the inductor capacitor, and summarized in that with a.

  According to the first aspect of the present invention, when the impedance of the load fluctuates, the frequency adjusting means adjusts the resonance frequency of the resonance system and the frequency of the AC power output from the AC voltage source to approach each other. Then, with the frequency adjusting means adjusted so that the resonance frequency of the resonance system and the frequency of the AC power output from the AC voltage source are close to each other, the capacitance of the capacitor is adjusted so that the power factor is improved by the constant changing means. At least one of the value and the inductance value of the inductor is changed.

As a result, even when the impedance of the load fluctuates, it is possible to suitably supply power from the AC voltage source to the load.
The contactless power transmission device according to claim 1, wherein the frequency adjustment unit causes the frequency of the AC power output from the AC voltage source to approach the resonance frequency of the resonance system, as described in claim 2. The frequency adjusting means adjusts the resonance frequency of the resonance system so as to approach the frequency of the AC power output from the AC voltage source. May be.

  According to the present invention, it is possible to suitably supply power from an AC voltage source to a load even if the impedance of the load varies.

The block diagram which shows typically the structure of the non-contact electric power transmission apparatus in 1st Embodiment. Explanatory drawing which shows the relationship between load resistance and efficiency. Explanatory drawing which shows the relationship between load resistance and efficiency. The block diagram which shows typically the structure of the non-contact electric power transmission apparatus in 2nd Embodiment.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the non-contact power transmission device 10 includes an AC voltage source 11, a primary side resonance coil 12 connected to the AC voltage source 11, a secondary side resonance coil 13, and a secondary side resonance coil. And a constant variable circuit 15 provided between the AC voltage source 11 and the primary side resonance coil 12. Capacitors 16 and 17 are connected in parallel to the primary resonance coil 12 and the secondary resonance coil 13, respectively.

  The primary side resonance coil 12 and the capacitor 16 constitute a primary side resonator, and the secondary side resonance coil 13 and the capacitor 17 constitute a secondary side resonator. And the primary side resonator and the secondary side resonator are comprised so that magnetic field resonance is possible. The constant variable circuit 15, the primary side resonance coil 12, the secondary side resonance coil 13, the load 14 and the capacitors 16 and 17 constitute a resonance system 18.

That is, the non-contact power transmission apparatus 10 includes a primary side resonator that receives power supplied from the AC voltage source 11 and a secondary side resonator that receives power from the primary side resonator.
The AC voltage source 11 is configured to be able to output high-frequency power (hereinafter referred to as AC power) using system power. Specifically, in the present embodiment, the AC voltage source 11 can change the frequency by switching operation of the switching element and can change the power value by changing the voltage value or the current value. Power.

  The primary side resonance coil 12 and the secondary side resonance coil 13 are formed of electric wires. For the electric wire constituting the coil, for example, an insulated vinyl-coated wire is used. The winding diameter and the number of turns of the coil are appropriately set according to the magnitude of power to be transmitted. In this embodiment, the primary side resonance coil 12 and the secondary side resonance coil 13 are formed in the same winding diameter. The primary side resonance coil 12 and the secondary side resonance coil 13 are formed in the same manner, and the same capacitors are used as the capacitors 16 and 17.

  The constant variable circuit 15 includes two variable capacitors 19 and 20 and an inductor 21. One variable capacitor 19 is connected in parallel to the AC voltage source 11, and the other variable capacitor 20 is connected in parallel to the primary side resonance coil 12. The inductor 21 is connected between the variable capacitors 19 and 20.

A detector 23 for detecting a voltage value and a current value is connected to the output line of the AC voltage source 11. A controller 22 is connected to the detector 23.
The non-contact power transmission apparatus 10 can be applied to a system that performs non-contact charging on a secondary battery mounted on a vehicle. Specifically, the secondary resonance coil 13, the capacitor 17 and the load 14 (in this embodiment, a constant circuit including a fixed capacitor and a fixed inductor, a rectifier and a secondary battery) are mounted on the vehicle. ing. Further, the AC voltage source 11, the capacitor 16, the primary side resonance coil 12, the constant variable circuit 15, the detector 23, and the controller 22 are provided in a charging device that supplies power to the secondary battery in a non-contact state. The device is installed on the ground side equipment (charging station).

In the present embodiment, the controller 22 constitutes frequency adjusting means. The constant variable circuit 15 and the controller 22 constitute constant changing means.
Next, the operation of the non-contact power transmission apparatus 10 configured as described above will be described.

  At the time of power transmission to the load 14, for example, power is supplied to the load 14 while the vehicle is stopped at a predetermined position near the power supply (charging) device. That is, the electric power received by the secondary side resonator is supplied to the load 14.

  The controller 22 adjusts so that the frequency of the AC power output from the AC voltage source 11 becomes the resonance frequency A [Hz] of the resonance system 18 and the power value becomes the power value α suitable for charging. Next, the controller 22 adjusts the capacity of the variable capacitors 19 and 20 of the constant variable circuit 15 based on the voltage value and current value detected from the detector 23 to improve the power factor. And the primary side resonator and secondary side resonator which received supply of electric power from the alternating voltage source 11 carry out magnetic field resonance. Thereby, the secondary resonator receives a part of the energy of the primary resonator. That is, the secondary resonator receives high frequency power from the primary side resonator.

  When it is detected by a charge amount monitor (not shown) that the charge amount of the secondary battery has exceeded the threshold value, and the controller 22 is notified that the charge amount of the secondary battery has exceeded the threshold value, the controller 22 The power value of the AC power output from the source 11 is changed from the power value α suitable for charging to the power value β for pushing charging. Then, the power value of the power input to the load 14 changes, and the impedance of the load 14 varies (hereinafter referred to as load variation). As a result, the resonance frequency of the resonance system 18 changes from A [Hz] to B [Hz].

  Therefore, the controller 22 specifies the resonance frequency B [Hz] of the resonance system 18 when the power value of the AC power output from the AC voltage source 11 is changed to β, and the frequency B [Hz] from the AC voltage source 11. AC power is output.

  In this embodiment, the controller 22 causes the AC voltage source 11 to output a plurality of AC power having a power value β and different frequencies from the AC voltage source 11, and detects each voltage value detected by the detector 23. The resonance frequency B [Hz] of the resonance system is specified based on the current value. More specifically, each impedance value is calculated from each voltage value and each current value detected when a plurality of AC power having different frequencies is output, and the resonance frequency B [Hz] of the resonance system is calculated based on each impedance value. Is identified. Then, AC power having a frequency B [Hz] is output from the AC voltage source 11.

Next, the controller 22 adjusts the capacitance values of the variable capacitors 19 and 20 of the constant variable circuit 15 based on each voltage value and each current value detected by the detector 23 to improve the power factor.
As a result, electric power is suitably supplied from the AC voltage source 11 to the load 14 (for example, a secondary battery).

Next, the relationship between load variation and efficiency will be described.
Due to a change in the power value of the power input to the load 14, a load change occurs, and two of “power factor state” and “resonance frequency of the resonance system (frequency at which efficiency is maximum)” change.

  Therefore, even if the power factor is improved with the output frequency fixed at an arbitrary frequency, the maximum efficiency cannot be obtained as shown in FIG. That is, in FIG. 2, when the load resistance becomes 800Ω, for example, the efficiency is about 60%, and the maximum efficiency cannot be obtained.

  On the other hand, when the load fluctuates, the resonance frequency of the resonance system is searched, the output frequency of the AC voltage source is changed to match the resonance frequency of the resonance system, and in this state, the constant variable circuit 15 is improved so as to improve the power factor. The capacity of the variable capacitors 19 and 20 is adjusted. As a result, as shown in FIG. 3, the efficiency can be close to 90% even when the load resistance changes to about 330Ω or 800Ω.

According to the above embodiment, the following effects can be obtained.
(1) When the controller 22 changes the power value of the power input to the load 14 to cause a load fluctuation, the resonance frequency of the resonance system 18 and the frequency of the AC power output from the AC voltage source 11 are Adjust to get closer (match). The constant of the constant variable circuit 15 is improved so that the power factor is improved by the controller 22 and the constant variable circuit 15 in a state where the resonance frequency of the resonance system 18 matches the frequency of the AC power output from the AC voltage source 11. Adjust. Therefore, even if load fluctuation occurs, it is possible to suitably supply power from the AC voltage source 11 to the load 14. As a result, power can be transmitted with maximum efficiency that does not depend on load fluctuations.

(2) The frequency of the AC power output from the AC voltage source 11 can be matched with the resonance frequency of the resonance system by the controller 22 as the frequency adjusting means.
(Second Embodiment)
Next, the second embodiment will be described focusing on the differences from the first embodiment.

  Instead of FIG. 1, in this embodiment, as shown in FIG. 4, a variable capacitor 30 is connected in parallel to the primary side resonance coil 12. A variable capacitor 31 is connected in parallel to the secondary resonance coil 13. The controller 22 can adjust the capacity of the variable capacitor 30 and the capacity of the variable capacitor 31. In this embodiment, the controller 22 and the variable capacitors 30 and 31 constitute frequency adjusting means.

As in the first embodiment, when power is transmitted to the load 14, for example, power is supplied to the load 14 while the vehicle is stopped at a predetermined position near the power supply (charging) device.
The controller 22 adjusts so that the frequency of the AC power output from the AC voltage source 11 becomes the resonance frequency A [Hz] of the resonance system 18 and the power value becomes the power value α suitable for charging. Next, the controller 22 improves the power factor by adjusting the capacitance values of the variable capacitors 19 and 20 of the constant variable circuit 15 based on the voltage value and current value detected from the detector 23.

  When it is detected by a charge amount monitor (not shown) that the charge amount of the secondary battery has exceeded the threshold value, and the controller 22 is notified that the charge amount of the secondary battery has exceeded the threshold value, the controller 22 Adjustment is made so that AC power having a frequency A [Hz] and a power value β is output from the source 11. Then, the power value of the power input to the load 14 changes and load fluctuation occurs. As a result, the resonance frequency of the resonance system 18 changes from A [Hz] to B [Hz].

  Therefore, the controller 22 determines that the resonance frequency of the resonance system 18 when the power value of the AC power output from the AC voltage source 11 is changed to β is the frequency A [Hz] of the AC power output from the AC voltage source 11. Adjust so that

  In the present embodiment, the controller 22 changes the capacitance value of the variable capacitor 30 and the capacitance value of the variable capacitor 31 a plurality of times, and at that time, based on each voltage value and each current value detected by the detector 23, The capacitance values of the variable capacitors 30 and 31 whose resonance frequency is the frequency A [Hz] are specified. Specifically, for example, each impedance value is calculated from each voltage value and each current value detected when the capacitance value of the variable capacitor 30 and the capacitance value of the variable capacitor 31 are changed a plurality of times. Based on this, the capacitance values of the variable capacitors 30 and 31 are specified so that the resonance frequency of the resonance system is the frequency A [Hz]. Then, the capacitance values of the variable capacitors 30 and 31 are adjusted so that the resonance frequency of the resonance system becomes the frequency A [Hz].

  Next, the controller 22 adjusts the capacitance values of the variable capacitors 19 and 20 of the constant variable circuit 15 based on the voltage value and current value detected from the detector 23 to improve the power factor. As a result, electric power is suitably supplied from the AC voltage source 11 to the load 14 (for example, a secondary battery).

According to the above embodiment, the following effects can be obtained.
(4) The controller 22 and the variable capacitors 30 and 31 can match the resonance frequency of the resonance system with the frequency of the AC power output from the AC voltage source 11.

The embodiment is not limited to the above, and may be embodied as follows, for example.
In the first embodiment and the second embodiment, the constant of the constant variable circuit 15 is changed so as to improve the power factor. However, the present invention is not limited to this, and the power factor is improved and the load 14 is applied in advance. You may adjust the constant of the constant variable circuit 15 so that the electric power of the defined electric power value may be input.

  In the first embodiment, after the load change, the frequency of the AC power output from the AC voltage source 11 is adjusted to be the resonance frequency of the resonance system. However, the present invention is not limited to this, and the AC voltage source after the load change The frequency of the AC power output from the AC power source 11 may be adjusted to a frequency closer to the resonance frequency B [Hz] of the resonant system 18 after the load change than the frequency of the AC power output from the AC voltage source 11 before the load change. .

  In the second embodiment, the capacitance values of the variable capacitors 30 and 31 are set so that the resonance frequency of the resonance system becomes the same as the frequency A [Hz] of the AC power output from the AC voltage source 11 after the load change. Although adjusted, the present invention is not limited to this, and the AC power output from the AC voltage source 11 is set to the resonance frequency of the resonance system 18 from the resonance frequency of the resonance system 18 after the load fluctuation and before the capacitance values of the variable capacitors 30 and 31 are adjusted. It is only necessary to adjust to a frequency close to the frequency A [Hz].

  The constant variable circuit 15 is not limited to one composed of two variable capacitors 19 and 20 and one inductor 21. For example, one of the variable capacitors 19 and 20 constituting the constant variable circuit 15 may be omitted, and the constant variable circuit 15 may be configured by one variable capacitor and one inductor 21, You may comprise only either one of an inductor. Further, the constant variable circuit 15 may be configured with a fixed capacitor and a variable inductor, and the constant may be changed by varying the variable inductor, or may be configured with a variable capacitor and a variable inductor, and the capacitance value of the variable capacitor. The constant may be changed by changing the inductance value of the variable inductor. In short, the constant variable circuit 15 may have any configuration as long as the power factor can be improved by changing the constant.

-The constant circuit provided in the vehicle should have at least a capacitor or an inductor. Further, the constant may be changed.
The adjustment of the resonance frequency of the resonance system 18, the adjustment of the frequency of the AC power output from the AC voltage source 11, and the adjustment of the power factor may be performed using a map. Under the condition that the displacement of each resonance coil 12, 13 does not occur, the power value of the AC power output from the AC voltage source 11, the frequency value to be changed after the load change, and the capacitance value of each variable capacitor 19, 20 Etc. can be calculated in advance.

  For example, in the first embodiment, the resonance frequency B [Hz] of the resonance system 18 that is changed when the power value of the AC power output from the AC voltage source 11 is changed to the power value β (when the load changes). ] And the constants of the constant variable circuit 15 (capacitance values of the variable capacitors 19 and 20) necessary for improving the power factor when the load fluctuates can be calculated in advance.

  Accordingly, a map in which the resonance frequency B [Hz] of the resonance system 18 at the time of load change and the constant of the constant variable circuit 15 that improves the power factor at the time of load change is set in correspondence with the power value β. Can be stored in a predetermined storage area (memory). In this case, when the power value of the AC power output from the AC voltage source 11 is changed to the power value β, the controller 22 refers to the map and changes the resonance frequency B [Hz] of the resonance system 18 and the constant variable. The constant of the circuit 15 is specified, the frequency of the AC voltage source 11 is changed based on the specification result, and the constant of the constant variable circuit 15 is changed. Thus, when the load changes, it is necessary to specify the resonance frequency B [Hz] of the resonance system 18 at the time of load change and the constant of the constant variable circuit 15 necessary for improving the power factor using the detector 23. Disappear.

  In the second embodiment, for example, a map in which the capacitance values of the variable capacitors 30 and 31 and the constants of the constant variable circuit 15 are set in correspondence with the power value β is represented by the predetermined storage area. Remember me. When the power value of the AC power output from the AC voltage source 11 is changed to the power value β, the controller 22 refers to the map and determines the capacitance values of the variable capacitors 30 and 31 and the constant variable circuit 15. The constants are specified, and the capacitance values of the variable capacitors 30 and 31 and the constants of the constant variable circuit 15 are changed based on the specified result. The map may be stored in a storage area separate from the controller 22.

The outer shape of the primary side resonance coil 12 and the secondary side resonance coil 13 is not limited to a circle, and may be a polygon such as a quadrangle, a hexagon, or a triangle, or may be an ellipse.
-The primary side resonance coil 12 and the secondary side resonance coil 13 are not restricted to the coil by which the electric wire was wound cylindrically, For example, it is good also as a shape by which the electric wire was wound on one plane.

  In the first embodiment, the parasitic capacitances of the primary side resonance coil 12 and the secondary side resonance coil 13 may be used instead of the capacitors 16 and 17. In this case, the resonance system includes a primary resonance coil 12, a secondary resonance coil 13, and a load 14.

  In the first embodiment, the primary side resonance coil and the secondary side resonance coil may not have the same winding diameter and number of turns, and the capacitors 16 and 17 may not use the same capacitor. .

A DC / DC converter or the like may be provided as the load 14.
The primary side resonator may include a primary coil and a primary side resonance coil, and the secondary side resonator may include a secondary side resonance coil and a secondary coil. That is, instead of forming a primary side resonator with one coil and a secondary side resonator with one coil, the primary side resonator receives the supply of power from the AC voltage source 11. A secondary side resonance coil for receiving electric power from the primary side resonance coil by magnetic field resonance, comprising a coil and a primary side resonance coil to which electric power is supplied from the primary coil by electromagnetic induction; The coil and the secondary coil which takes out the electric power received by the secondary side resonance coil by electromagnetic induction may be comprised.

  In the above embodiment, magnetic field resonance is used to realize non-contact power transmission. However, the present invention is not limited to this, and electromagnetic induction may be used.

  DESCRIPTION OF SYMBOLS 10 ... Non-contact electric power transmission apparatus, 11 ... AC voltage source, 12 ... Primary side resonance coil, 13 ... Secondary side resonance coil, 14 ... Load, 15 ... Constant variable circuit, 18 ... Resonance system, 19 ... Variable capacitor, 20 ... variable capacitor, 21 ... inductor, 22 ... controller, 23 ... detector, 30 ... variable capacitor, 31 ... variable capacitor.

Claims (3)

  1. AC voltage source,
    A primary-side resonator that receives power from the AC voltage source;
    A secondary resonator that receives power from the primary resonator;
    A load to which the power received by the secondary resonator is supplied;
    With
    In a non-contact power transmission device that forms a resonance system with at least the primary side resonator, the secondary side resonator, and the load,
    Frequency adjusting means for adjusting the resonance frequency of the resonance system and the frequency of the AC power output from the AC voltage source when the impedance of the load fluctuates,
    The power factor is improved in a state in which at least one of a capacitor or an inductor is provided and the resonance frequency of the resonance system and the frequency of the AC power output from the AC voltage source are adjusted by the frequency adjusting unit. Constant changing means for changing at least one of the capacitance value of the capacitor or the inductance value of the inductor,
    A non-contact power transmission device comprising:
  2.   2. The non-contact power according to claim 1, wherein the frequency adjusting unit adjusts the frequency of the AC power output from the AC voltage source so as to approach the resonance frequency of the resonance system. Transmission equipment.
  3.   2. The non-contact power according to claim 1, wherein the frequency adjusting unit adjusts the resonance frequency of the resonance system so as to approach the frequency of the AC power output from the AC voltage source. Transmission equipment.
JP2012151568A 2012-07-05 2012-07-05 Non-contact power transmission device Pending JP2014017893A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017136491A1 (en) * 2016-02-02 2017-08-10 Witricity Corporation Controlling wireless power transfer systems

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017136491A1 (en) * 2016-02-02 2017-08-10 Witricity Corporation Controlling wireless power transfer systems
US10263473B2 (en) 2016-02-02 2019-04-16 Witricity Corporation Controlling wireless power transfer systems

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