JP2017192218A - Non-contact power supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-contact power supply device for supplying power to a power reception coil from one or some of a plurality of power transmission coils, the non-contact power supply device being capable of suppressing power consumption or generation of a leakage magnetic flux at a power transmission coil not participating in the power supply, with a simple configuration.SOLUTION: A high-frequency power source 80 supplies high-frequency power of a sine waveform or pseudo sine waveform to power transmission coils 71, 72. The power transmission coils 71, 72 include parallel capacitors 711, 712 connected in parallel to the power transmission coils, respectively. Values of the parallel capacitors 711, 712 are set to resonate with self-inductance of the power transmission coils 71, 72 connected in parallel to the capacitors, respectively, at a power source frequency of the high frequency power source 80. Impedance at the time of a power reception coil 81 not facing a power transmission coil 71 (or at the time of no load) is maximized, minimizing current flowing through the power transmission coil 71.SELECTED DRAWING: Figure 1

Description

  The present invention is a non-contact power supply device that includes a plurality of power transmission coils, and a power reception coil that receives power from some of the power transmission coils. Generation is suppressed.

The present inventors have previously proposed a traveling non-contact power feeding system that performs non-contact power feeding to a vehicle traveling on a road (Patent Document 1 below). FIG. 8 shows an embodiment of one of the contactless power feeding devices.
This non-contact power feeding device applies a high-frequency voltage to a plurality of primary power feeding transformers (power transmission coils) 1, 2, 3, 4 and power transmission coils 1, 2, 3, 4 that are spaced apart from the ground traveling path. It has a high frequency power supply 40 to be applied and a secondary power supply transformer (power receiving coil) 20 mounted on the vehicle, and the power transmission coils 1, 2, 3, 4 are connected in parallel. A series capacitor C1 is connected between the high frequency power supply 40 and the series capacitor C2 between the power receiving coil 20 and the rectifier circuit 51.

Capacitors C1 and C2 are inserted to increase the efficiency of contactless power feeding. As shown in FIG. 8, the system in which the series capacitor C1 is connected to the power transmission coil side of the non-contact power feeding apparatus and the series capacitor C2 is connected to the power reception coil side is called “SS system”.
The value of the capacitor C1 is such that the capacitor C1 and the power transmission coil form a series resonance circuit when the power frequency of the high frequency power source 40 is ω and the self-inductance of each power transmission coil 1, 2, 3, 4 is L1. = 1 / (ω ² L1) (Equation 1)
Further, the value of the capacitor C2 is set so that the capacitor C2 and the power receiving coil 20 form a series resonance circuit when the self-inductance of the power receiving coil 20 is L2, C2 = 1 / (ω ² L2) ( Number 2)
Is set.

  In this non-contact power feeding device, when the vehicle travels and the power receiving coil 20 installed on the back surface of the floor of the vehicle is magnetically coupled to any one of the power transmitting coils 1, 2, 3, and 4, the power transmitting coil (in FIG. 8) In this case, contactless power feeding from the power transmission coil 2) to the power reception coil 20 is performed. Further, when the power receiving coil 20 moves to the middle between the power transmission coil 2 and the power transmission coil 3, non-contact power feeding is continuously performed by the magnetic flux generated from the power transmission coil 2 and the power transmission coil 3. Therefore, non-contact power feeding is performed without interruption to the traveling vehicle.

  However, in the SS system, a power transmission coil that is not involved in power supply to the power receiving coil 20, that is, a power transmission coil at the time of no load (power transmission coils 1, 3, and 4 in the case of FIG. 8) is also supplied to the power receiving coil 20. The current equivalent to that of the power transmission coil (in the case of FIG. 8, the power transmission coil 2) that is involved in the current flows and leakage flux is generated.

Non-Patent Document 1 below proposes a traveling non-contact power feeding system that improves the drawbacks of the SS method.
In the non-contact power feeding device of this system, as shown in FIG. 9, power transmission coils and magnetic sensors 61 are alternately arranged along the traveling path, and before and after the magnetic sensor 61 that detects the magnetism of the permanent magnet 62 on the vehicle side. Only the power transmission coil is configured to be activated.
Further, an LCL resonator 63 is connected to the front stage of the SS type power transmission coil.
FIG. 10 shows an equivalent circuit of a power transmission coil and a power reception coil to which the LCL resonator 63 is connected. An inductor L11 and a parallel capacitor C11 are connected to an SS transmission coil L12 to which the series capacitor C12 is connected. In FIG. 10, R11, R12, and R2 indicate internal resistances of the inductor L11, the power transmission coil L12, and the power reception coil L2, respectively.

In this circuit, parameters are set so that the resonance frequency is ω0 and the relationship of the following equation is satisfied.
ω ₀ L ₁₁ = 1 / (ω ₀ C ₁₁ ) = ω ₀ L ₁₂ −1 / (ω ₀ C ₁₂ ) (Equation 3)
ω ₀ L ₂ = 1 / (ω ₀ C ₂ ) (Equation 4)
The equivalent impedance Rin on the primary side of this circuit is expressed by the following equation (Equation 5).
When there is no load when the power receiving coil L2 is not opposed to the power transmitting coil L12, RL is ∞ and R12 is substantially 0, so that Rin = ∞ and i11 = 0. Further, when the power receiving coil L2 faces the power transmitting coil L12, RL and Rin are decreased and i11 is increased.
In this non-contact power feeding device, when the power transmission coil is started based on the detection of the magnetic sensor 61, as shown in FIG. 11, the primary side voltage ν1, the primary side current i11, and the secondary side current i12 are considerably exceeded. It is reported that a shoot is seen and it takes 800 μs to decay. It is explained that this is because the resonator has no attenuation characteristic.

JP, 2014-147160, A

Kai Song, Chunbo Zhu, Kim Ean Koh, Takehiro Imura & Yoichi Hori "Wireless Power Transfer for Running EV Powering Using Multi-Parallel Segmented Rails" {HYPERLINK "http://ieeexplore.ieee.org/xpl/mostRecentIssue.jsp?punumber = 7127333 ", Emerging Technologies: Wireless Power (WoW), 2015 IEEE PELS Workshop}

However, the non-contact power feeding device described in Non-Patent Document 1 has a complicated structure because it has vehicle detection means, means for starting a power transmission coil based on the detection result, and the like. Take the trouble. Further, the overshoot that appears when the power transmission coil is started is not preferable because it causes unnecessary leakage magnetic flux.
The power feeding to the power receiving coil using a part of the plurality of power transmitting coils is not limited to power feeding while the vehicle is running, and can be used in many fields. It is expected to spread.
In order to expand the use of this non-contact power supply device, it is required to take environmentally friendly measures such as simplifying the configuration, facilitating management, and suppressing leakage magnetic flux as much as possible.

  The present invention was devised in consideration of such circumstances, and when non-contact power feeding is performed from a part of the plurality of power transmission coils to the power receiving coil, power consumption and leakage in the power transmission coil not involved in power feeding are disclosed. It aims at providing the non-contact electric power feeder which can suppress generation | occurrence | production of magnetic flux by simple structure.

In the present invention, when a plurality of power transmission coils connected in parallel are supplied with high frequency power from a common high frequency power source, and the power receiving coil is opposed or magnetically coupled to some of the plurality of power transmission coils, A non-contact power feeding device that performs non-contact power feeding from a part of the power transmission coil to the power receiving coil without interrupting the electrical connection between the power transmission coil and the high-frequency power source. Alternatively, each of the power transmission coils has a parallel capacitor connected in parallel to the power transmission coil, and the value of the parallel capacitor is equal to the self inductance of the power transmission coil connected in parallel and the power source of the high frequency power supply. It is set to resonate at a frequency.
In this non-contact power supply device, since the power transmission coil and the parallel capacitor constitute a parallel resonance circuit, the impedance when the power reception coil is not opposed to the power transmission coil (that is, when there is no load) is the maximum, and the power transmission coil The current that flows through is minimized.

  In the non-contact power feeding device of the present invention, the power receiving coil has a series capacitor connected in series with the power receiving coil, and the value of the series capacitor is set so that the power receiving coil and the series capacitor are in series resonance.

In the non-contact power feeding device of the present invention, the number of power transmission coils is two or more, and the number of power reception coils is smaller than the number of power transmission coils.
Although the number of power receiving coils may be plural, the number of power transmitting coils exceeds the number of power receiving coils.

Moreover, in the non-contact electric power feeder of this invention, it is desirable that the number of turns N1 of the power transmission coil is larger than the number of turns N2 of the power receiving coil.
As the turn ratio N1 / N2 between the power transmission coil and the power reception coil increases, the ratio of the current I2 flowing through the power reception coil to the current I1 flowing through the power transmission coil increases, and the amount of power supplied to the power reception coil increases.

In the contactless power supply device of the present invention, the high-frequency power source includes a plurality of single-phase inverters that convert a DC voltage into an AC voltage, and an AC voltage that is output from the plurality of single-phase inverters in series. It is desirable to configure with an insulating transformer that obtains a voltage, and to connect to each of the power transmission coils via a reactor.
By this high frequency power supply, a pseudo sine wave from which many orders of harmonics are removed can be generated. The reactor is inserted to further suppress harmonics.

  Further, in the non-contact power feeding device of the present invention, the high-frequency power source is configured by a full bridge inverter that generates a pseudo sine wave voltage by PWM control or a current source inverter that outputs a current close to a sine wave by PWM control, You may make it connect with each of a power transmission coil via a reactor.

  Further, the non-contact power feeding device of the present invention is installed separately along the traveling path of the movable body in which a plurality of power transmission coils can travel, and the power receiving coil is installed on the back surface of the floor of the movable body, The present invention can be used in a traveling non-contact power feeding system in which non-contact power feeding is performed from a power transmitting coil facing or magnetically coupled to a power receiving coil of a moving body to the power receiving coil.

  Further, the non-contact power feeding device of the present invention is installed separately from a parking lot of a moving body in which a plurality of power transmission coils can travel, and a receiving coil is installed on the back surface of the floor of the moving body, It can be used for a parking system in which contactless power feeding is performed from a power transmission coil facing or magnetically coupled to the power reception coil to the power reception coil.

  Moreover, the power transmission coil and the power receiving coil of the non-contact power feeding device of the present invention can also be used as a non-contact outlet of a direct current distribution system that distributes direct current to a home or office.

  In the non-contact power feeding device of the present invention, the power receiving coil and the power transmitting coil opposed to or magnetically coupled to the power receiving coil can be detected without detecting the power transmitting coil facing the power receiving coil or selecting the power transmitting coil to be activated. Efficient non-contact power feeding is performed between them, and the current supply to the power transmission coil regardless of the power feeding is automatically limited.

The figure which shows the non-contact electric power feeder which concerns on embodiment of this invention The figure which shows the high frequency power supply of FIG. The figure explaining the generation | occurrence | production principle of the pseudo sine wave by the high frequency power supply of FIG. Diagram showing measurement position of voltage / current in simulation circuit The figure which shows the voltage and electric current waveform in each measurement position in the circuit of two power transmission coils and one power reception coil Diagram showing voltage and current waveforms at each measurement position with the reactor removed The figure which shows the voltage and electric current waveform in each measurement position in the circuit of three power transmission coils and two power reception coils A diagram showing a conventional non-contact power feeding system during traveling The figure which shows the non-contact electric power feeding system during driving | running | working described in the nonpatent literature 1 Equivalent circuit in the system of FIG. The figure which shows the overshoot at the time of the power transmission coil starting described in the nonpatent literature 1

FIG. 1 shows a non-contact power feeding apparatus according to an embodiment of the present invention.
This device has a plurality (two in FIG. 1) of power transmission coils 71 and 72 connected in parallel, parallel capacitors 711 and 712 connected in parallel to the power transmission coils 71 and 72, and power transmission coils 71 and 72. A high-frequency power supply 80 that applies a high-frequency voltage having a pseudo sine waveform, a reactor 73 inserted to suppress harmonics generated from the high-frequency power supply 80, and a part of the power transmission coil 72 are opposed or magnetically coupled to supply power. Power receiving coil 81, a series capacitor 811 connected in series to power receiving coil 81, and a load 812 connected to power receiving coil 81.

  The high-frequency power source 80 includes a plurality of single-phase inverters 801 and 802 that convert a DC voltage into an AC voltage, and an insulating transformer 803 that obtains a pseudo sine wave voltage by combining the AC outputs of the single-phase inverters 801 and 802. The transformer 803 is magnetically coupled to the primary coil 8031 supplied with the AC output of the single-phase inverter 801, the primary coil 8032 supplied with the AC output of the single-phase inverter 802, and the primary coil 8031 and the primary coil 8032. And the next coil 8033.

The value of the parallel capacitor 711 is set so that the power transmission frequency of the high frequency power supply 80 forms the power transmission coil 71 and the parallel resonance circuit, and the parallel capacitor 712 configures the power transmission frequency of the power transmission coil 72 and the parallel resonance circuit. Is set to that value.
When the power frequency of the high-frequency power source 80 is ω, the self-inductance of each of the power transmission coil 71 and the power transmission coil 72 is L1, and the values of the parallel capacitor 711 and the parallel capacitor 712 are C1, the values of the parallel capacitor 711 and the parallel capacitor 712 are Whether setting is made so that the output power factor of the high-frequency power supply 80 becomes 1 with the power receiving coil 81 facing the power transmitting coil 72 (so that the voltage applied to the primary circuit and the flowing current are in phase). Or
C1 = 1 / (ω ² L1) (Equation 6)
Set to be.

In addition, the value of the series capacitor 811 connected to the power receiving coil 81 is L2 as the self-inductance of the power receiving coil 81 and C2 as the value of the series capacitor 811.
C2 = 1 / (ω ² L2) (Equation 7)
Set to be.
The PS resonance type non-contact power supply device in which the value of the parallel capacitor 712 connected to the power transmission coil 72 and the value of the series capacitor 811 connected to the power reception coil 81 are set in this way has an equivalent circuit equivalent to an ideal transformer. The input voltage on the primary side is V1, the input current is I1, the output voltage output to the secondary load is V2, the output current is I2, and the ratio of the number of turns N1 of the power transmission coil and the number of turns N2 of the power receiving coil is When a (= N1 / N2),
V1 = a × V2 (Equation 8)
I1 = (1 / a) × I2 (Equation 9)
Thus, efficient non-contact power feeding becomes possible. Further, the output current I2 can be increased by increasing a (= N1 / N2).

On the other hand, in the power transmission coil 71 not facing the power receiving coil 81, the power transmission coil 71 and the parallel capacitor 711 constitute a parallel resonance circuit. The current that flows is minimized.
Therefore, power consumption in the power transmission coil 71 is small, and generation of unnecessary leakage magnetic flux from the power transmission coil 71 is suppressed.

In the PS resonance type non-contact power feeding device, as described in Japanese Patent No. 4644827, it is necessary to use a power source whose output waveform is a sine waveform as the high frequency power source 80.
Here, as shown in FIG. 2, the outputs of two single-phase full-bridge inverters 801 and 802 are multiplexed in series by an insulating transformer 803 to obtain a pseudo-sine waveform output.
As shown in FIG. 3, the single-phase full-bridge inverter 801 is controlled to output the pulse voltage shown in FIG. 3A, and the single-phase full-bridge inverter 802 is controlled so that the phase difference from FIG. Is set to 36 °, and the pulse voltage shown in FIG. When these are connected in series by an insulating transformer 803, a pseudo sine wave shown in FIG. 3C is obtained. FIG. 3D shows an output current waveform when a load is connected to the isolation transformer 803.

When the pulse width control is performed by setting the phase shift amount of each of the two inverters to 60 °, the third harmonic of the output voltage is removed, and when the phase difference between the two inverters is set to 36 °, the operation is performed. The fifth harmonic of the output voltage is removed. By changing the phase shift amount of the two inverters and the phase difference between the two inverters, the harmonics to be canceled can be changed. Further, if the number of inverters to be multiplexed is increased and the number of levels of the output voltage is increased, it becomes possible to remove higher-order harmonics (“Power Electronics Handbook”, Ohm, July 20, 2010). Issued on the day).
Further, the high frequency power supply 80 including the insulating transformer 803 is safe even if a ground fault of the power transmission coils 71 and 72 occurs.

Next, the result of simulating the characteristics of this non-contact power feeding device will be described. In this simulation, a high-frequency power source (third-order / fifth-removed series single-phase multiple inverter) in which the outputs of a plurality of single-phase inverters are multiplexed in series to remove the third and fifth harmonics was used.
The equivalent circuit is shown in FIG. FIG. 4 shows the circuit position where the voltage and current values were measured. The voltage measurement position is indicated by a letter enclosed in a square, and the current measurement position is indicated by a letter enclosed in a circle.

FIG. 5 shows the characteristics of the non-contact power feeding apparatus having two power transmission coils and one power receiving coil. FIG. 5A shows voltage waveforms at the A position and the B position. FIG. 5B shows a current waveform at the C position. FIG. 5C shows a voltage waveform at the H position. FIG. 5D shows current waveforms at the F position and the D position. FIG. 5E shows current waveforms at the E position and the G position. The horizontal axis of the figure represents time.
FIG. 6 shows the results of measuring the voltage or current at each position under the same conditions as in FIG. 5 except for the reactor 73 from the circuit of FIG.
FIG. 7 shows characteristics when the number of power transmission coils is increased to three and the number of power reception coils is increased to two. FIG. 7A shows voltage waveforms at the A position and the B position. FIG. 7B shows a current waveform at the C position. FIG. 7C shows voltage waveforms at the H position of the two power receiving coils. FIG. 7D shows current waveforms at the F position of the two power transmission coils facing the two power receiving coils and the D position of the power transmission coil not facing the power receiving coil. FIG. 7E shows current waveforms at the E position of the power transmission coil not facing the power receiving coil and the G position of the two power transmission coils facing the power receiving coil.

From FIG. 5D, it can be seen that in this non-contact power feeding device, almost no current flows to the power transmission coil that does not face the power reception coil, and current is supplied only to the power transmission coil that faces the power reception coil.
Moreover, it can be seen from FIGS. 6B and 6D that when the reactor 73 is removed, harmonic current flows through the power transmission coil.
Further, from FIG. 7D, even if the number of power transmission coils increases, almost no current flows in the power transmission coils that are not opposed to the power reception coils, and current is supplied only to the power transmission coils that are opposed to the power reception coils. I understand.
Further, from the comparison between FIG. 5B and FIG. 7B, it can be seen that when the number of power receiving coils is increased to two, the supply current of the high-frequency power source is doubled. Therefore, it turns out that operation | movement of a some load is possible.
Thus, in this non-contact power feeding device, power can be supplied from the high-frequency power source only to the power transmission coil facing (or magnetically coupling) with the power receiving coil.

  Although an example in which a plurality of single-phase inverters are multiplexed and used as a high-frequency power source that generates a sine wave is shown here, other high-frequency power sources may be used. For example, a full bridge inverter that generates a pseudo sine wave voltage by PWM control, a current source inverter that outputs a current close to a sine wave by PWM control, or the like may be used.

  Moreover, the power supply amount to a receiving coil can be increased by making the winding number N1 of a power transmission coil larger than the winding number N2 of a receiving coil. This is clear from (Equation 9).

The non-contact power feeding device of the present invention can be used in a traveling non-contact power feeding system in which a plurality of power transmission coils are installed on a traveling path of a moving body to feed power to the traveling moving body.
It can also be used in a parking system in which a plurality of power transmission coils are arranged in a parking lot and power is supplied to a moving vehicle that is parked.
It can also be used as a non-contact outlet of a DC distribution system that distributes DC to homes and offices.

  The non-contact power feeding device of the present invention has a simple structure, can save power and suppress unnecessary electromagnetic field radiation, and is used in various fields such as a power feeding system during traveling, a power feeding system during parking, and a DC power distribution system. be able to.

61 Magnetic sensor 62 Permanent magnet 63 LCL resonator 71 Power transmission coil 72 Power transmission coil 73 Reactor 80 High frequency power supply 81 Power reception coil 711 Parallel capacitor 712 Parallel capacitor 801 Single phase inverter 802 Single phase inverter 803 Insulation transformer 811 Series capacitor 812 Load 8031 Primary coil 8032 Primary coil 8033 Secondary coil

Claims (10)

When a plurality of power transmission coils connected in parallel are supplied with high frequency power from a common high frequency power source, and the power receiving coil is opposed to or magnetically coupled to a part of the power transmission coils, the other power transmission coils A non-contact power feeding device that performs non-contact power feeding from the part of the power transmission coil to the power receiving coil without interrupting the electrical connection between the high-frequency power source and the high-frequency power source,
The high-frequency power supply supplies high-frequency power having a sine waveform or pseudo sine waveform to the power transmission coil,
Each of the power transmission coils has a parallel capacitor connected in parallel to the power transmission coil,
The value of the parallel capacitor resonates with the self-inductance of the power transmission coil connected in parallel and the power frequency of the high frequency power source, or is set so that the power factor of the output of the high frequency power source is 1.
The non-contact electric power feeder characterized by the above-mentioned.   2. The contactless power supply device according to claim 1, wherein the power receiving coil includes a series capacitor connected in series to the power receiving coil, and the value of the series capacitor is determined by the self-inductance of the power receiving coil and the high frequency power source. A non-contact power feeding device that is set to resonate at a power source frequency.   2. The non-contact power feeding device according to claim 1, wherein the number of the power transmission coils is two or more, and the number of the power receiving coils is smaller than the number of the power transmission coils. .   2. The contactless power supply device according to claim 1, wherein the number N1 of turns of the power transmission coil is larger than the number N2 of turns of the power receiving coil.   2. The contactless power supply device according to claim 1, wherein the high-frequency power source combines a plurality of single-phase inverters that convert a DC voltage into an AC voltage, and an AC voltage output from the plurality of single-phase inverters in series. A non-contact power feeding device comprising: an insulating transformer that obtains a pseudo sine wave voltage and connected to each of the power transmission coils via a reactor.   2. The contactless power supply device according to claim 1, wherein the high-frequency power source includes a full-bridge inverter that generates a pseudo sine wave voltage by PWM control, and is connected to each of the power transmission coils via a reactor. A non-contact power feeding device.   2. The contactless power supply device according to claim 1, wherein the high-frequency power source includes a current source inverter that outputs a current close to a sine wave by PWM control, and is connected to each of the power transmission coils via a reactor. The non-contact electric power feeder characterized by this.   The contactless power feeding device according to claim 1, wherein the plurality of power transmission coils are installed separately along a travel path of a movable body on which the plurality of power transmission coils can travel, and the power reception coil is disposed on a floor of the movable body. A non-contact power feeding device configured to perform non-contact power feeding to the power receiving coil from the power transmitting coil that is installed on the back surface and that is opposed to or magnetically coupled to the power receiving coil of the moving body that is running.   The contactless power supply device according to claim 1, wherein the plurality of power transmission coils are installed apart from a movable parking lot, and the power reception coil is provided on a back surface of the floor of the mobile body. A non-contact power feeding apparatus in which non-contact power feeding is performed to the power receiving coil from the power transmitting coil that is installed and parked or magnetically coupled to the power receiving coil of the parked moving body.   8. The non-contact power feeding device according to claim 1, wherein the plurality of power transmission coils and power receiving coils are used in a non-contact outlet of a direct current distribution system that distributes direct current. apparatus.