JP2013120890A - Electromagnetic induction non-contact power transmission coil and electromagnetic induction non-contact power transmission apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic induction non-contact power transmission coil and an electromagnetic induction non-contact power transmission apparatus capable of suppressing a leakage electromagnetic field without using a magnetic material, a metal shield, or the like.SOLUTION: In the electromagnetic induction non-contact power transmission coil including a pair of transmission side coil and a reception side coil where a conductor is wound spirally on the same plane, and transmitting power to the reception side coil by electromagnetic induction by feeding a current to the transmission side coil, two sets of transmission coil (51 and 53, 52 and 54) are provided. Two transmission side coils (51, 52) in the two sets of transmission coil (51 and 53, 52 and 54) are arranged at intervals so that respective conductors are flush with each other, and the currents flow reversely through the conductors.

Description

  The present invention relates to an electromagnetic induction type non-contact power transmission coil and an electromagnetic induction type non-contact power transmission device.

  Electromagnetic induction type non-contact power transmission is equipped with a transmission coil consisting of a power transmission side coil and a power reception side coil, and the current flux is changed by passing current through the power transmission side coil. This is the principle that induced current flows through the power and power is transmitted. For this reason, since the change in magnetic flux increases as the amount of power to be transmitted increases, the electromagnetic field leaking from the transmission coil may adversely affect surrounding devices and the human body. One method for suppressing the leakage electromagnetic field is to use a magnetic material or a metal shield.

JP 2010-093180 A

  However, this method can suppress the influence on the surroundings, but has a disadvantage that the cost increases and the weight of the entire transmission system increases.

  Accordingly, the present invention provides an electromagnetic induction type non-contact power transmission coil and an electromagnetic induction type non-contact power transmission device that can suppress a leakage electromagnetic field without using a magnetic material, a metal shield, or the like. And

  The invention according to claim 1 for solving the above-described problem includes a transmission coil having a pair of power transmission side coils and a power reception side coil in which a conductor is spirally wound on the same plane, and a current is supplied to the power transmission side coil. An electromagnetic induction type non-contact power transmission coil that transmits power to the power receiving side coil by electromagnetic induction by flowing a current, comprising two sets of the transmission coils (51 and 53, 52 and 54), The two power transmission side coils (51, 52) in the transmission coils (51, 53, 52, 54) are spaced apart from each other so that the respective conductors are in the same plane, The present invention is characterized in that the flowing currents flow in opposite directions.

  According to a second aspect of the present invention for solving the above-described problem, in the electromagnetic induction type non-contact power transmission coil according to the first aspect, the two power transmission side coils (51, 52) are respectively connected to each other. It is characterized by being formed in a reverse spiral shape.

  The invention according to claim 3 for solving the above-described problem includes a transmission coil having a power transmission side coil and a power reception side coil, and transmits power to the power reception side coil by electromagnetic induction caused by flowing a current through the power transmission side coil. An electromagnetic induction type non-contact power transmission device to perform, wherein the transmission coil is an electromagnetic induction type non-contact power transmission coil according to claim 1 or 2.

  Note that the reference numerals in parentheses in the description of the means for solving the above-described problems correspond to the reference numerals of the constituent elements in the description of the mode for carrying out the invention below. It is not intended to limit the interpretation of the claims.

  According to the first aspect of the present invention, two sets of the transmission coils are provided, and the two power transmission side coils in the two sets of transmission coils are spaced apart from each other so that the respective conductors are in the same plane. Since the currents flowing through the conductors are configured to flow in opposite directions, generation of unnecessary electromagnetic fields in the surroundings can be reduced without using a magnetic material or a metal shield.

  According to the second aspect of the present invention, since the two power transmission side coils are each formed in a spiral shape in which the conductors are opposite to each other, currents that are opposite to each other flow in the respective conductors. Generation of unnecessary electromagnetic fields can be reduced without using a magnetic material or a metal shield.

  According to the third aspect of the present invention, the electromagnetic induction type non-contact power includes the transmission coil having the power transmission side coil and the power reception side coil, and transmits power to the power reception side coil by electromagnetic induction by passing a current through the power transmission side coil. A transmission device, wherein the transmission coil is the electromagnetic induction type non-contact power transmission coil according to any one of claims 1 to 3, so that generation of an unnecessary electromagnetic field around the magnetic material or metal shield It can be reduced without using etc.

The present invention and a conventional electromagnetic induction type non-contact power transmission coil are shown, (A) is a configuration diagram of an embodiment of the present invention, (B) is a configuration diagram of a conventional system. It is a figure explaining the direction of the electric current in the electromagnetic induction system non-contact electric power transmission coil of this invention, and the direction of magnetic flux, (A) is a schematic plan view, (B) is a schematic front view. It is shown in the solid graph which visualized the electric field strength characteristic of a far field (electric field), (A) is a characteristic figure of the transmission coil of this invention, (B) is a characteristic figure of the transmission coil of a conventional system. When the circumference angle of the far field represented by the polar coordinate system shown in FIG. 5 (angle around the z-axis starting from the x-axis) φ = 90 °, the distance r from the origin and the angle θ from the z-axis = −180 It is the electric field strength characteristic graph of the transmission coil of this invention which plotted the numerical value of the electric field strength (dBV / m) in the range to-+ 180. It is a figure which shows a polar coordinate system. Magnetic field strength characteristics of the transmission coil of the present invention and the conventional method in which the numerical value of the magnetic field strength (dBA / m) of the near magnetic field is plotted when z = 0 in the yz section in the near field represented by the Cartesian coordinate system shown in FIG. FIG. It is a figure which shows a Cartesian coordinate system. It is a graph which shows the transmission characteristic with respect to the change of the transmission frequency at the time of performing non-contact transmission between the power transmission side coil and the power receiving side coil. It is explanatory drawing which shows the structure of one Embodiment of the electromagnetic induction type non-contact electric power transmission apparatus which concerns on this invention. It is a block diagram which shows the structure of one Embodiment of the electromagnetic induction type non-contact electric power transmission apparatus which concerns on this invention.

(Embodiment of electromagnetic induction type non-contact power transmission coil)
FIG. 1A is a configuration diagram of an embodiment of an electromagnetic induction type non-contact power transmission coil according to the present invention. In FIG. 1, an electromagnetic induction type non-contact power transmission coil 50 includes a pair of a power transmission side coil (primary side coil) 51 (52) and a power reception side coil (secondary side coil) which are overlapped at a predetermined interval. Two sets of transmission coils having 53 (54) are provided. The power transmission side coil 51 (52) is a planar coil in which the conductor is spirally wound on the same plane, and the lead terminal 51a (52a) which is one end of the conductor and the lead terminal 51b (52b) which is the other end. Have Similarly to the power transmission side coil, the power reception side coil 53 (54) is a planar coil in which the conductor is spirally wound on the same plane, and the lead terminal 53a (54a) which is one end portion of the conductor and the other end portion. A certain lead terminal 53b (54b) is provided.

  The two sets of transmission coils are arranged side by side in parallel with a predetermined interval so that the conductors of the two power transmission side coils 51 and 52 are in the same plane, and the two power reception side coils 53 and 54 are The power transmission side coils 51 and 52 are respectively superimposed on the corresponding power transmission side coils 51 and 52 at a predetermined interval, and the whole excluding the lead terminal portion (the power transmission side coils 51 and 52 and the power reception side coils 53 and 54) is sealed by resin packaging. It is fixed by fixing means (not shown) such as sandwich fixing by a resin casing. Each coil 51-54 which comprises the electromagnetic induction system non-contact electric power transmission coil 50 has the square planar coil shape of the same dimension of 60 mm x 100 mm, for example, The predetermined space | interval of the parallel arrangement of the power transmission side coils 51 and 52 is as follows. For example, it is 10 mm.

  When the electromagnetic induction type non-contact power transmission coil 50 performs power transmission by electromagnetic induction from the power transmission side transmission coils 51, 52 to the power reception side coils 53, 54, as shown by arrows in FIG. The directions of currents flowing through the power transmission side coils 51 and 52 are opposite to each other (for example, clockwise in the power transmission side coil 51 and counterclockwise in the power transmission side coil 52), and the direction of the magnetic flux is indicated by an arrow in FIG. Are generated opposite to each other. That is, one power transmission side coil (for example, the power transmission side coil 51) is formed in a square planar coil shape in which a conductor is wound in a clockwise spiral shape from one end (lead terminal 51a) to the other end (lead terminal 51b). Thus, a current flows in a direction from one end (lead terminal 51a) to the other end (lead terminal 51b), and the other power transmission side coil (for example, power transmission side coil 52) has one end (lead terminal 52a). ) From the other end (lead terminal 52b) to the other end (lead terminal 52b), and the other end (lead terminal 52b) is directed in the direction from the one end (lead terminal 52a) to the other end (lead terminal 52b). A current is passed through. In this way, in the power transmission side coil 51 and the power transmission side coil 52, the magnetic fluxes generated in the opposite directions are canceled by the currents flowing in the opposite directions through the conductors formed in the opposite spiral shapes, thereby, It is possible to reduce leakage of unnecessary electromagnetic fields generated around.

  The effect of the configuration of the transmission coil of the present invention was verified using an electromagnetic field simulator (FEKO).

  For comparison with the transmission coil of the present invention, the transmission coil 60 having the conventional structure shown in FIG. 1B is formed in a square planar coil shape and has a structure in which the transmission coils 60 are overlapped at a predetermined interval. It comprises a side coil (primary side coil) 61 and a power receiving side coil (secondary side coil) 62. The power transmission side coil 61 has lead terminals 61a and 61b, and the power reception side coil 62 has lead terminals 62a and 62b. The entire transmission coil 60 is fixed by fixing means such as sealing by resin packaging (not shown) and sandwich fixing by a resin casing. The transmission coil 60 has a size of 130 mm × 100 mm so as to be the same size as the transmission coil of the present invention shown in FIG.

The difference in leakage electromagnetic field between the transmission coil having the conventional structure and the transmission coil of the present invention was confirmed using an electromagnetic field simulator (FEKO). The simulation condition is that the frequency used for power transmission between the power transmission side coil (primary side coil) and the power reception side coil (secondary side coil) is 800 kHz, and two sets of power transmission side coils (primary side coils) 51 connected in series. , 52 is applied to the primary side coil of the conventional method of FIG. 1B (1.41 V) (the power transmission side coil (primary Since the input impedances (R) of the side coils 51, 52, 61 are all 50Ω, 0.04 W of power is input to the primary side coil of the present invention and the conventional method by power P = V ² / R. Applied) and matched the conditions.

  As for the simulation results, a solid graph in which the electric field strength of the far field (electric field) is first visualized is shown in FIG. 3A and 3B are three-dimensional graphs of the electric field strength in the transmission coil of the present invention and the conventional method in a three-dimensional coordinate system, respectively. In the transmission coil of the conventional system shown in FIG. 3B, the outermost contour of the sphere shows an electric field strength of approximately −60 dBV, and in the transmission coil of the present invention system shown in FIG. The outer contour shows an electric field strength of approximately −110 dBV, and it can be clearly seen that the electric field strength of the coil of the present invention is smaller when comparing FIGS. 3 (A) and 3 (B).

  FIG. 4 shows a distance r from the origin and an angle from the z axis when the circumference angle (angle around the z axis starting from the x axis) φ = 90 ° of the far field represented by the polar coordinate system shown in FIG. It is the electric field strength characteristic graph which plotted the numerical value of the electric field strength (dBV / m) in the range from θ = −180 to +180.

  In FIG. 4, a comparison is made between the electric field strength characteristic A of the transmission coil of the present invention having the configuration shown in FIG. 1A and the electric field strength characteristic B of the conventional transmission coil having the configuration shown in FIG. It was found that by using the transmission coil of the invention, an electric field of about 50 dB at maximum could be suppressed as compared with the conventional transmission coil.

  FIG. 6 is a magnetic field strength characteristic diagram plotting numerical values of the magnetic field strength (dBA / m) of the near magnetic field when z = 0 in the yz section of the near field represented by the Cartesian coordinate system shown in FIG. FIG. 6 compares the electric field strength characteristic A of the transmission coil of the present invention having the configuration shown in FIG. 1A with the electric field strength characteristic B of the conventional transmission coil having the configuration shown in FIG. It has been found that by using the transmission coil of the invention, the leakage magnetic field to the periphery of about 50 dB at the maximum can be reduced as compared with the transmission coil of the conventional system.

  FIG. 8 illustrates transmission characteristics (transmission efficiency characteristics A and reflection characteristics B) with respect to changes in transmission frequency when non-contact power transmission is performed between the power transmission coils 51 and 52 and the power reception coils 53 and 54 by electromagnetic induction. The impact survey results are shown. At a transmission frequency of 800 kHz in which the simulation was performed, the transmission rate was 98%, and the reflection characteristics showed a good result close to 0%, and transmission by performing non-contact power feeding between the power transmission side coils 51 and 52 and the power reception side coil. There was almost no adverse effect on properties (decrease in efficiency, increase in reflection).

  As described above, according to the electromagnetic induction type non-contact power transmission coil of the present invention, the two power transmission side coils 51 and 52 are arranged in parallel, and the directions of the magnetic fields generated by the two power transmission side coils 51 and 52 are mutually different. By constituting in the opposite direction, the magnetic fluxes cancel each other, and generation of unnecessary electromagnetic fields around the surroundings can be reduced without using a conventional magnetic body, metal shield, or the like.

  In the electromagnetic induction type non-contact power transmission coil according to the above-described embodiment, the entire two sets of transmission coils having a pair of power transmission side coil and power reception side coil are covered with fixing means except for the lead terminals. However, as a modification, only the two power transmission side coils 51 and 52 arranged in parallel may be covered with fixing means such as resin packaging except for the lead terminals. In this case, the corresponding two power receiving side coils 53 and 54 are separately separated by a fixing means such as resin packaging.

  Moreover, although the power transmission side coil and the power receiving side coil are formed in a rectangular planar coil shape, the shape is not limited to this, and may be other shapes such as a circular planar coil shape.

  Moreover, although the power transmission side coil and the power reception side coil are made into the same dimension, a different dimension may be sufficient, for example, you may make a power reception side coil small.

(Embodiment of non-contact power transmission device)
Next, an embodiment of the non-contact power transmission apparatus according to the present invention using the above-described electromagnetic induction type non-contact power transmission coil of the present invention will be described with reference to FIG. 9 and FIG.

  FIG. 9 is an explanatory diagram showing a configuration of an embodiment of the electromagnetic induction type non-contact power transmission apparatus according to the present invention. In this embodiment, a case will be described in which a power transmission side coil and a power reception side coil each use a separate electromagnetic induction type non-contact power transmission coil.

  As shown in the figure, the electromagnetic induction type non-contact power transmission device 10 according to the present embodiment is provided outside the electric vehicle 5 with the power receiving device 12 provided in the electric vehicle 5 and supplies AC power to the power receiving device 12. Power supply device 11 to be supplied, and AC power output from power supply device 11 is transmitted to power reception device 12 in a non-contact (wireless) manner. The power feeding device 11 includes a communication coil 24 for power transmission. When AC power is supplied to the communication coil 24, the AC power is supplied to the power reception communication coil 31 provided in the power receiving device 12. Is transmitted to.

  The power receiving device 12 provided in the electric vehicle 5 includes a power receiving communication coil 31 that approaches the power transmitting communication coil 24 and a rectifier 33 when the electric vehicle 5 is placed at a predetermined position of the power feeding device 11 during charging. And. Furthermore, a battery 35 charged with DC power, a DC / DC converter 42 that steps down the voltage of the battery 35 and supplies it to the sub-battery 41, an inverter 43 that converts output power of the battery 35 into AC power, A motor 44 driven by AC power output from the inverter 43 is provided.

  FIG. 10 is a block diagram of the electromagnetic induction type non-contact power transmission device 10 according to the embodiment of the present invention, and includes a power feeding device 11 and a power receiving device 12 mounted on the electric vehicle 5.

  The power supply apparatus 11 is amplified by a carrier oscillator 21 that outputs a carrier signal for power transmission, a power amplifier 23 that amplifies the carrier signal (that is, AC power) output from the carrier oscillator 21, and the power amplifier 23. A communication coil 24 that outputs AC power is provided. As the communication coil 24, the above-described power transmission side coils 51 and 52 are connected in series. That is, the lead terminal 51b of the power transmission side coil 51 and the lead terminal 52a of the power transmission side coil 52 are connected, and the lead terminal 51a of the power transmission side coil 51 and the lead terminal 52b of the power transmission side coil 52 are connected to one of the power amplifiers 23 and Connect to the other output terminal.

  The carrier oscillator 21 outputs, for example, AC power having a frequency of 800 [kHz] as an AC signal for power transmission.

  The power amplifier 23 amplifies the AC power output from the carrier transmitter 21. The amplified AC power is output to the communication coil 24 (power transmission side coils 51 and 52). The communication coil 24 (power transmission side coils 51 and 52) wirelessly transmits AC power to the communication coil 31 provided in the power receiving device 12.

  The power receiving device 12 includes a power receiving communication coil 31 that receives AC power transmitted from the power transmitting communication coil 24 (power transmission side coils 51 and 52), and AC power received by the communication coil 31. And a rectifier 33 that generates a DC voltage. Further, a battery 35 that supplies electric power to a vehicle driving motor 44 (see FIG. 9) is provided, and the battery 35 is charged with DC power output from the rectifier 33. As the communication coil 31, the above-described power receiving coils 53 and 54 of the transmission coil are connected in series. That is, the lead terminal 53b of the power receiving side coil 53 and the lead terminal 54a of the power receiving side coil 54 are connected, and the lead terminal 53a of the power receiving side coil 53 and the lead terminal 54b of the power receiving side coil 54 are connected to one side and the other side of the rectifier 33, respectively. Connect to the input terminal.

  Next, the operation of the electromagnetic induction type non-contact power transmission apparatus of the present invention will be described. As shown in FIG. 9, the electric vehicle 5 is placed at a predetermined position of the power feeding device 11, and is provided in the communication coil 24 (power transmission side coils 51 and 52) provided in the power feeding device 11 and the power receiving device 12 of the electric vehicle 5. The battery 35 can be charged when the communication coil 31 (the power receiving side coils 53, 54) is at a facing position.

  When charging is started, AC power having a frequency of 800 [kHz] is output from the carrier oscillator 21 shown in FIG.

  Then, the AC power output from the carrier transmitter 21 is amplified by the power amplifier 23. The amplified AC power is transmitted to the power receiving device 12 via the communication coil 24 (power transmission side coils 51 and 52) and the communication coil 31 (power reception side coils 53 and 54).

  The AC power transmitted to the power reception device 12 is output from the communication coil 31 (power reception side coils 53 and 54) to the rectifier 33.

  The rectifier 33 rectifies AC power and converts it into DC power of a predetermined voltage, supplies this power to the battery 35, and charges the battery 35. Thereby, the battery 35 can be charged.

  As described above, according to the electromagnetic induction type non-contact power transmission device of the present invention, by using the electromagnetic induction type non-contact power transmission coil of the present invention as a communication coil for power feeding, the leakage electromagnetic field to the surroundings can be reduced. An electromagnetic induction type non-contact power transmission device with reduced generation can be provided.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this, A various deformation | transformation and application are possible.

  For example, in the above-described embodiment, as shown in FIG. 2, each of the power transmission side coils 51 and 52 is formed in a spiral shape in which each conductor is opposite to each other, but instead, each conductor is the same. They may be formed in a spiral shape that rotates in the direction, and the currents flowing through the conductors may flow in opposite directions.

  Moreover, in the above-mentioned embodiment, although the frequency used for the electric power transmission between a power transmission side coil (primary side coil) and a power receiving side coil (secondary side coil) is 800 kHz, it is not restricted to this, and other frequencies are also used. Similarly, the effect of reducing the leakage electromagnetic field can be obtained.

50 Transmission coil (electromagnetic induction type non-contact power transmission coil)
51, 52 Power transmission side coil 53, 54 Power reception side coil

Claims (3)

An electromagnetic system comprising a transmission coil having a pair of power transmission side coil and power reception side coil in which a conductor is spirally wound on the same plane, and transmitting power to the power reception side coil by electromagnetic induction by passing a current through the power transmission side coil Inductive contactless power transmission coil,
Comprising two sets of said transmission coils;
The two power transmission side coils in the two sets of the transmission coils are arranged so as to be spaced apart from each other so that the conductors are in the same plane, and the currents flowing through the conductors flow in opposite directions to each other. An electromagnetic induction type non-contact power transmission coil, characterized in that In the electromagnetic induction type non-contact power transmission coil according to claim 1,
In the two power transmission side coils, each of the conductors is formed in a spiral shape opposite to each other. An electromagnetic induction type non-contact power transmission coil. An electromagnetic induction type non-contact power transmission device comprising a transmission coil having a power transmission side coil and a power reception side coil, and performing power transmission to the power reception side coil by electromagnetic induction by passing a current through the power transmission side coil,
The electromagnetic induction type non-contact power transmission coil according to claim 1, wherein the transmission coil is an electromagnetic induction type non-contact power transmission coil.

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