JP2015008547A - Non-contact power charger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-contact power charger capable of reducing an induction voltage to a metal substance disposed adjacent to a coil and radiation noises due to leakage current flowing to a floating capacitance.SOLUTION: A primary side electric field shield 14 disposed adjacent to a primary side coil 18 is connected to an output terminal of a primary side rectification circuit with primary side connection means 15, and a secondary side electric field shield 20 disposed adjacent to a secondary side coil 19 is connected to an output terminal of a secondary side rectification circuit 22 with secondary side connection means 26. Thereby the induction voltage to a metal substance is prevented. With this, not only accident such as electric shock can be prevented and the safety is increased but also leakage current flowing to floating capacitance between the first and secondary coils and a metal substance can be reduced and thus radiation noises can be reduced.

Description

  The present invention relates to a non-contact charging device used for charging an electric propulsion vehicle such as an electric vehicle or a plug-in hybrid vehicle.

  FIG. 12 is a schematic diagram showing a configuration of a conventional non-contact charging device 106. In FIG. 12, the non-contact power feeding device (primary side) F connected to the power panel of the ground-side power source 109 supplies power to the power receiving device (secondary side) G mounted on the electric propulsion vehicle. It arrange | positions so that it may oppose through the air gap which is a space | gap space without a physical connection. In this arrangement state, when an alternating current is applied to the primary coil 107 provided in the power feeding device F to form a magnetic flux, an induced electromotive force is generated in the secondary coil 108 provided in the power receiving device G. Electric power is transmitted from the coil 107 to the secondary coil 108 without contact.

  The power receiving device G is connected to the in-vehicle battery 110, for example, and the in-vehicle battery 110 is charged with the electric power transmitted as described above. The in-vehicle motor 111 is driven by the electric power stored in the in-vehicle battery 110. Note that, during the non-contact power supply process, for example, the wireless communication device 112 exchanges necessary information between the power supply device F and the power reception device G.

  FIG. 13 is a schematic diagram illustrating the internal structure of the power feeding device F and the power receiving device G. In particular, FIG. 13A is a schematic diagram illustrating an internal structure when the power feeding device F is viewed from above and the power receiving device G is viewed from below. FIG. 13B is a schematic diagram illustrating an internal structure when the power feeding device F and the power receiving device G are viewed from the side.

  In FIG. 13, the power feeding device F includes a primary coil 107, a primary magnetic core 113, a back plate 115, a cover 116, and the like. Briefly speaking, the power receiving device G has a symmetric structure with the power feeding device F, and includes a secondary coil 108, a secondary magnetic core 114, a back plate 115, a cover 116, and the like. The surface of the primary magnetic core 113 and the surfaces of the secondary coil 108 and the secondary magnetic core 114 are covered and fixed with a mold resin 117 mixed with a foam material 118, respectively.

  That is, in both the power feeding device F and the power receiving device G, the mold resin 117 is filled between the back plate 115 and the cover 116, and the primary coil 107, the secondary coil 108, the primary magnetic core 113, and the secondary magnetic core are contained therein. The surface of 114 is covered and fixed. The mold resin 117 is made of, for example, a silicon resin. By hardening the interior in this way, the primary and secondary coils 107 and 108 are positioned and fixed, and the mechanical strength is ensured and the heat dissipation function is also exhibited. That is, the primary and secondary coils 107 and 108 generate heat due to Joule heat through an exciting current, but are radiated and cooled by heat conduction of the mold resin 117.

JP 2008-87733 A

  Since the power feeding device F is disposed below the vehicle, there is a possibility of riding on the power feeding device F when the vehicle is parked. In order to withstand such a load, it is desirable that the back plate 115 is made of a metal material. However, if the metal back plate 115 is disposed in the vicinity of the primary coil, an induced voltage is generated, resulting in a risk of electric shock. In addition, since the power feeding device F is installed outdoors, there is a possibility that a metal substance may approach the outside of the cover 116, but there is a risk of electric shock in the vicinity of the primary coil. Further, when a metal material is disposed in the vicinity of the primary coil, a leakage current flowing in the stray capacitance between the primary coil and the metal material increases.

  In particular, as shown in FIG. 12, when the power feeding device F is installed so as to be in contact with the ground, the leakage current 29 flowing in the stray capacitance between the primary coil and the ground increases, and not only electric shock but also noise increases. There are also issues such as In addition, the operation becomes unstable, for example, the leakage breaker malfunctions. Even if the ground line of the commercial power source 6 and the metal back plate 27 are connected as a countermeasure against electric shock due to the leakage current to the metal back plate 27 even when not installed on the ground, the leakage current is grounded in the same manner as the above-described problem. There is a problem that noise increases due to flowing in the line.

  Further, in order to withstand vibration during traveling in the power receiving device G, the back plate and the connecting portion between the back plate and the vehicle body are preferably made of metal. Further, when a metal material is disposed in the vicinity of the secondary coil, the leakage current 30 flowing in the stray capacitance between the secondary coil and the metal material increases as shown in FIG. There are also challenges.

  Therefore, an object of the present invention is to provide a non-contact charging device capable of suppressing not only an induced voltage to a metal material disposed in the vicinity of the primary and secondary coils but also a leakage current.

  In order to achieve the above object, the present invention provides a power feeding device that supplies power to a power receiving device in a contactless manner, and the power feeding device is input with a power conversion circuit that generates a high-frequency alternating current from a commercial power source. A primary coil that generates a magnetic flux by the high-frequency alternating current, an electric field shield disposed in the vicinity of the primary coil, and connection means for connecting the electric field shield to a power conversion circuit.

  According to another aspect of the present invention, there is provided a power receiving device that receives power supply contactlessly from the power feeding device side, and the power receiving device generates an electromotive force according to a magnetic flux generated by a primary coil on the power feeding device side. A secondary coil that rectifies the electric power input from the secondary coil and outputs it to the battery, an electric field shield disposed in the vicinity of the secondary coil, and the electric field shield for the 2 Connecting means for connecting to the secondary side rectifier circuit.

  According to the present invention, the power feeding device and the power receiving device of the non-contact charging device are arranged in the vicinity of the primary and secondary coils by being connected to the stable potential of the power conversion circuit or rectifier circuit by the electric field shield and the connecting means, respectively. It is possible to suppress the induced voltage on the metal material.

Block diagram of a non-contact charging device provided with a power control device according to the present invention External view of the non-contact charging device of FIG. 1 (viewed from the side of the vehicle) External view of the non-contact charging device of FIG. 1 (viewed from the rear of the vehicle) 1 is a side cross-sectional view of the ground coil unit of FIG. 1 and shows a state in which a primary-side electric field shield 14 is disposed so as to cover a primary-side coil 18. The figure which shows the state which has arrange | positioned the primary side electric field shield 14 between the primary side coil 18 and the metal backplate 27 by the side sectional drawing of the ground coil unit. The figure which shows the state which has arrange | positioned the primary side electric field shield 14 between the primary side coil 18 and the metal backplate 27, and the primary side coil 18 side surface by sectional drawing of the same ground coil unit. The figure which shows the state which has arrange | positioned the primary side electric field shield 14 between the primary side coil 18 and the cover 28 in the sectional side view of the ground coil unit. The figure which shows the state which has arrange | positioned the primary side electric field shield 14 between the primary side coil 18 and a cover, and the primary side coil 18 side surface. (A) is a top view of the primary-side electric field shield 14 (20) in FIG. 1 (b) is a top view showing another form of the primary-side electrolytic shield 14 (20). Top view of coil 18 (19) and field shield 14 (20) of FIG. The figure which shows how the leakage current of FIG. 4 flows Schematic diagram showing the configuration of a conventional non-contact charging device The schematic diagram which shows the internal structure of the power receiving apparatus (power feeding apparatus) arrange | positioned facing the power feeding apparatus (power receiving apparatus) of FIG.

  One embodiment of the present invention is a power supply device that supplies power to a power receiving device in a contactless manner, and the power supply device generates a high-frequency alternating current from a commercial power source, and the input high-frequency alternating current A primary coil for generating magnetic flux, an electric field shield disposed in the vicinity of the primary coil, and connection means for connecting the electric field shield to a power conversion circuit.

  Another embodiment of the present invention is a power receiving device that receives power supply contactlessly from the power feeding device side, and the power receiving device generates an electromotive force according to magnetic flux generated in a primary coil on the power feeding device side. A secondary coil that is generated, a secondary side rectifier circuit that rectifies power input from the secondary coil and outputs the rectified power to a battery, an electric field shield disposed in the vicinity of the secondary coil, and the electric field shield. Connecting means for connecting to the secondary side rectifier circuit.

  According to such a configuration, even when high-frequency alternating current flows through the primary and secondary coils during power transmission and a high voltage is generated in each coil, the metallic material disposed near the primary and secondary coils Induction voltage can be suppressed, accidents such as electric shock can be prevented, and safety is improved.

  Moreover, the leakage current which flows into the stray capacitance between the primary and secondary coils and the metal material can be reduced, and radiation noise can be suppressed.

  The electric field shield is preferably made of a low resistivity material such as non-magnetic stainless steel, aluminum, or copper. By using a substance having a low resistivity, even if the magnetic flux generated from the power transmission coil and the electric field shield are magnetically coupled and induction-heated, it is possible to provide a highly safe electrolytic shield with a small amount of heat generation. Further, by making the shape in which the loop through which the induction current flows is cut so as not to be induction-heated, the temperature rise of the electric field shield itself can be prevented.

  Furthermore, the electric field shield has a thickness equal to or less than the penetration depth of the induction current determined by the frequency of the high-frequency current flowing through the primary and secondary coils and the above-described material, thereby preventing a temperature rise due to induction heating.

  The connecting means is connected to the power conversion circuit or the secondary rectifier circuit via a predetermined impedance. This impedance is an impedance of a line connecting the electric field shield and the circuit, and is very small, so that it can be a stable potential of the power conversion circuit or the secondary side rectifier circuit to which the electric field shield itself is connected.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

  FIG. 1 is a block diagram of a contactless charging apparatus according to the present invention. Moreover, FIG.2 and FIG.3 is an external view of the state in which the vehicle was installed in the parking space. As shown in FIGS. 1, 2, and 3, the non-contact charging device includes a power feeding device 2 installed in a parking space, for example, and a power receiving device 4 mounted on an electric propulsion vehicle, for example.

  The power feeding device 2 includes a primary side rectifier circuit 8 connected to a commercial power source 6, an inverter unit 10, a power conversion circuit 17 including a control unit (for example, a microcomputer) 16, primary side coils 18 and 1. A coil unit 12 having a secondary electric field shield 14 and a connecting means 25 for connecting the primary electric field shield 14 and the output terminal of the primary rectifier circuit are provided.

  On the other hand, the power receiving device 4 includes a coil unit 21 including a secondary coil 19 and a secondary electric field shield 20, a secondary rectifier circuit 22, a load (battery) 23, and a control unit (for example, a microcomputer). ) 24, and secondary side connection means 26 for connecting the secondary side electric field shield 20 and the secondary side rectifier circuit 22.

  In the power supply device 2, the commercial power source 6 is a 200 V commercial power source that is a low-frequency AC power source, and is connected to the input end of the primary side rectifier circuit 8. The output end of the primary side rectifier circuit 8 is the input of the inverter unit 10. The output end of the inverter unit 10 is connected to the coil unit 12. On the other hand, in the power receiving device 4, the output end of the coil unit 21 is connected to the input end of the secondary side rectifier circuit 22, and the output end of the secondary side rectifier circuit 22 is connected to the battery 23. Further, the primary side electric field shield 14 is connected to the output terminal (either the high potential side or the low potential side) of the primary side rectifier circuit 8 by the connecting means 25.

  Further, the coil unit 12 is laid on the ground, and the power conversion circuit 17 is erected at a position separated from the coil unit 12 by a predetermined distance, for example. On the other hand, the coil unit 21 is attached to, for example, the bottom of the vehicle body (for example, a chassis).

  The control unit 16 performs wireless communication with the control unit 24, and the control unit 24 determines a power command value according to the detected remaining voltage of the battery 23 and transmits the determined power command value to the control unit 16. The control unit 16 compares the supplied power detected by the coil unit 12 with the received power command value, and drives the inverter unit 10 to obtain the power command value.

  During power feeding, the control unit 24 detects the received power and changes the power command value to the control unit 16 so that the battery 23 is not overcurrent or overvoltage.

  As shown in FIG. 2, when power is supplied from the power feeding device 2 to the power receiving device 4, the coil unit 21 is disposed so as to face the coil unit 12 by appropriately moving the vehicle, and the control unit 16 causes the inverter unit 10 to operate. By controlling the driving, a high-frequency electromagnetic field is formed between the coil unit 12 and the coil unit 21. The power receiving device 4 takes out electric power from the high frequency electromagnetic field and charges the battery 23 with the taken out electric power.

  FIG. 4 is a sectional view of the side surface of the coil unit 12.

  As shown in FIG. 4, the primary side coil 18, a metal back plate 27, and a cover 28 that covers the upper and side surfaces of the coil unit 12 are provided. In FIG. 4, the primary side electric field shield 14 is disposed so as to cover the primary side coil 18. In this way, the outside of the primary side coil 18 that generates a high frequency high voltage is covered with the primary side electric field shield 14 that is connected to the output terminal of the primary side rectifier circuit 8 by the connecting means 25 and has a stable potential. Even if there is a metallic substance in the vicinity of the primary side coil 18, it is possible to suppress the induced voltage, and safety can be improved.

  Further, as shown in FIG. 5, when the possibility of inserting a metal substance around the ground coil unit is low, the primary side electric field shield 14 is disposed only between the primary side coil 18 and the metal back plate 27. May be.

  Furthermore, as shown in FIG. 6, it is unlikely that a metal material will be inserted into the upper part of the coil unit 12, but if there is a possibility that a metal material will be inserted in the vicinity of the side surface, The primary side electric field shield 14 may be disposed only between the primary side coil 18 and the metal back plate 27.

  As shown in FIG. 4 to FIG. 6, by arranging the primary electric field shield 14 between the primary coil 18 and the back plate 27, the coil unit 12 is placed on the outdoor ground (on the ground) as shown in FIG. 11), the metal back plate 27 is at ground (earth) potential, but the leakage current i0 flowing through the stray capacitance between the primary coil 18 and the ground is as shown in FIG. It becomes possible to suppress the generated noise. In addition, malfunction of the earth leakage breaker can be suppressed.

  As shown in FIGS. 7 and 8, if the strength of the back plate 27 is not a problem, the primary electric field shield 14 may be disposed only in the direction in which the metal material may be inserted around the ground coil unit.

  As described above, the primary-side electric field shield 14 not only improves the safety but also reduces the leakage current flowing in the stray capacitance between the primary or secondary side coil and the metal material, thereby radiating noise. Can be suppressed.

  The same applies to the secondary-side electric field shield 20 of the coil unit 21, but there is no problem even if the shapes of the primary-side electric field shield 14 and the secondary-side electric field shield 20 are different.

  The metal electric field shield disposed in the vicinity is not induction-heated by the high-frequency current flowing through the primary side coil 18 and the secondary side coil 19. An upper schematic view of the electric field shield is shown in FIG. When the electric field shield arranged so as to face the primary side coil 18 and the secondary side coil 19 has the shape shown in FIG. 9A, the induced current in the figure flows and induction heating occurs.

  Therefore, as shown in FIG. 9B, the path through which the induced current flows is cut. The number of cuts may be further increased from the shape shown in FIG.

  Further, since the amount of magnetic flux is large on the inner side than the inner peripheral part of the primary and secondary coils and on the outer side of the outer peripheral part of the coil, the inner diameter of the electric field shield is increased in the case of the shape shown in FIG. Is equal to or greater than the inner diameter of the coil and the outer shape of the electric field shield is equal to or smaller than the outer shape of the coil. The shape is shown in FIG. By making the shape as shown in FIG. 10, the temperature rise of the electric field shield can be suppressed.

  Furthermore, an electric field shield may be arranged only on either the primary side or the secondary side.

  It is to be noted that, by appropriately combining arbitrary embodiments of the various embodiments described above, the effects possessed by them can be produced.

  As described above, in the power feeding device and the power receiving device of the non-contact charging device according to the present invention, it is possible to suppress the induced voltage on the metal substance disposed in the vicinity of the coil during power feeding from the power feeding device to the power receiving device. Can be prevented. In addition, it is possible to suppress the leakage current flowing in the stray capacitance between the coil and the metal material, and to reduce radiation noise.

  With the configuration as described above, safety can be improved and noise can be reduced, which is useful for feeding power to a power receiving device of an electric propulsion vehicle.

DESCRIPTION OF SYMBOLS 2 Electric power feeder 4 Power receiving device 6 Commercial power supply 8 Primary side rectifier circuit 10 Inverter part 12 Coil unit 14 Primary side electric field shield 16 Control part 17 Power conversion circuit 18 Primary side coil 20 Secondary side electric field shield 21 Vehicle side coil unit 22 Secondary side rectifier circuit 23 Battery 24 Power receiving device side control unit

Claims (4)

  A power supply device that supplies power to a power receiving device in a contactless manner, the power supply device including a power conversion circuit that generates a high-frequency alternating current from a commercial power supply, and a primary coil that generates a magnetic flux by the input high-frequency alternating current And a non-contact charging device comprising: a conductor disposed in the vicinity of the primary coil; and primary side connection means for connecting the conductor to a power conversion circuit.   The non-contact charging device according to claim 1, further comprising a primary side rectifier circuit that rectifies a commercial power supply, wherein a primary side connection unit is connected to an output terminal of the primary side rectifier circuit.   The contactless charging apparatus according to claim 1, wherein the conductor is grounded by the primary side connecting means.   A power receiving device that receives power supply in a non-contact manner from a power feeding device side, wherein the power receiving device includes a secondary coil that generates an electromotive force according to a magnetic flux generated in a primary coil on the power feeding device side, and the secondary coil Secondary side rectifier circuit that rectifies the power input from the battery and outputs it to the battery, a conductor disposed in the vicinity of the secondary coil, and a secondary side that connects the conductor to the secondary side rectifier circuit A contactless charging device comprising a connection means.

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