JP2013215073A - Feeding apparatus and power reception apparatus for non-contact power transmission system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To completely detect the presence of foreign matters in a feeding apparatus and a power reception apparatus used for non-contact power transmission.SOLUTION: The feeding apparatus 2 includes: a primary coil 26 for generating a magnetic flux by an input alternating current; a cover 29 for covering a primary coil 26; and a sensor coil 28 for detecting an object present around the cover 29. The winding axis of the sensor coil 28 is substantially orthogonal to that of the primary coil 26. Thus, mutual interference between the sensor coil 28 and the primary coil 26 can be suppressed, and an object present around the cover 29 of the feeding apparatus 2 can be completely detected by fluctuations in resonance frequencies of the sensor coil 28.

Description

  The present invention relates to a power feeding device and a power receiving device of a non-contact power transmission system used for charging an electric propulsion vehicle such as an electric vehicle or a plug-in hybrid vehicle.

  FIG. 8 is a schematic diagram showing a configuration of a conventional non-contact power transmission system 106. In FIG. 8, a power feeding device (primary side) F connected to the power panel of the ground-side power source 109 physically supplies power to a power receiving device (secondary side) G mounted on an electric propulsion vehicle. It arrange | positions so that it may oppose through the air gap which is a space | gap space without a 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 on-vehicle motor 111 is driven by the electric power stored in the 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. 9 is a schematic diagram illustrating the internal structure of the power feeding device F and the power receiving device G. In particular, FIG. 9A 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. 9B 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. 9, 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 inside in this way, the primary coil 107 and the secondary coil 108 are positioned and fixed, and the mechanical strength is ensured and the heat dissipation function is also exhibited. That is, the primary coil 107 and the secondary coil 108 generate heat by Joule heat through an exciting current, but are radiated and cooled by heat conduction of the mold resin 117.

JP 2008-87733 A

The power feeding device F is installed in a garage or the like, but does not realize that a foreign object is placed on the cover 116 of the power feeding device F, and stops the vehicle on the power feeding device F to transmit power or transmit power. It is also possible that an animal or the like enters inside. In particular, a metal object, which is an example of a foreign object, is present on the cover 116 during power transmission, and if left as it is, the metal object is overheated. In particular, when a foreign object such as a loop-shaped conductor capable of interlinking magnetic flux is inserted between the primary coil 107 and the secondary coil 108, an electromotive force is generated at both ends of the conductor. . From the above, when foreign matter exists between the primary coil 107 and the secondary coil 108 during power transmission, it is required to reliably detect the presence of the foreign matter.

  Therefore, an object of the present invention is to provide a power feeding device and a power receiving device that are used in a non-contact power transmission system that can reliably detect the presence of a foreign object between the power feeding device and the power receiving device.

  In order to achieve the above object, a power supply device of a contactless power transmission system according to the present invention is a power supply device that supplies power to a power receiving device in a contactless manner, and generates a magnetic flux by an input alternating current. And a cover that covers the primary coil and a sensor coil that detects an object present around the cover, and the winding axis of the sensor coil is configured to be substantially orthogonal to the winding axis of the primary coil.

  The power receiving device of the non-contact power transmission system of the present invention is a power receiving device that receives power in a non-contact manner from the power feeding device, and generates a secondary electromotive force by a magnetic flux generated by a primary coil of the power feeding device. A coil, a cover that covers the secondary coil, and a sensor coil that detects an object present around the cover, wherein the winding axis of the sensor coil is substantially orthogonal to the winding axis of the secondary coil It is said.

  According to the present invention, the power feeding device or the power receiving device includes a sensor coil capable of detecting an object on the cover, and the winding axis of the sensor coil is configured to be substantially orthogonal to the winding axis of the primary coil. It is possible to reliably detect the presence of foreign matter while suppressing mutual interference.

Block diagram of a non-contact power transmission system according to the present invention External view of the non-contact power transmission system of FIG. External view of the non-contact power transmission system of FIG. Top view of the appearance of the non-contact power transmission system of FIG. (A) (b) Explanatory drawing of the mutual interference of the coil of a non-contact electric power transmission system (A) (b) External view of an embodiment of sensor arrangement of the non-contact power transmission system of FIG. (A) (b) Flow chart showing foreign object detection and transmission power control Schematic diagram showing the configuration of a conventional non-contact power transmission system 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.

  1st invention is the electric power feeder which supplies electric power to a power receiving apparatus non-contacting, Comprising: The primary coil which generate | occur | produces magnetic flux with the input alternating current, the cover which covers the said primary coil, and the periphery of the said cover exist A sensor coil that detects an object to be detected, and the winding axis of the sensor coil is substantially orthogonal to the winding axis of the primary coil.

  In a second aspect of the present invention, a magnetic material such as ferrite is disposed in the vicinity of the primary coil, and the sensor coil is wound around the magnetic material.

In a third aspect of the present invention, a plurality of the sensor coils are installed, and the sensor coils adjacent in the winding axis direction are set so that the generated magnetic flux is in the opposite direction.

  A fourth invention is a power receiving device that receives power from a power feeding device in a contactless manner, and covers a secondary coil that generates an induced electromotive force by a magnetic flux generated by a primary coil of the power feeding device, and covers the secondary coil A cover and a sensor coil for detecting an object present around the cover are provided, and the winding axis of the sensor coil is configured to be substantially orthogonal to the winding axis of the secondary coil.

  In a fifth aspect of the present invention, a magnetic material such as ferrite is disposed in the vicinity of the secondary coil, and the sensor coil is wound around the magnetic material.

  In a sixth aspect of the present invention, a plurality of the sensor coils are installed, and the sensor coils adjacent in the winding axis direction are set so that the generated magnetic flux is in the opposite direction.

  According to such a configuration, if there is an object around the cover of the power feeding device or the power receiving device, the impedance around the sensor coil changes, and the resonance frequency of the sensor coil shifts and can be detected. In addition, since the winding axis of the sensor coil is substantially orthogonal to the winding axis of the primary coil, mutual interference between the coils can be suppressed and the presence of an object (foreign matter) can be reliably detected. Therefore, excessive temperature rise of the invading foreign matter can be prevented, expansion damage such as equipment failure can be prevented in advance, and safety is improved.

  By winding the sensor coil so as to wind the magnetic material, the performance of the sensor coil can be ensured with a small number of turns.

  By operating the sensor coils adjacent in the winding axis direction so that the generated magnetic flux is in the opposite direction, the magnetic flux generated from the sensor coil can be directed closer to the cover outer direction near the sensor coil. The presence of an object (foreign matter) can be detected more accurately.

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

  FIG. 1 is a block diagram of a non-contact power transmission system including a power feeding device according to the present invention. 2 and 3 are external views of a state where the vehicle is stopped in the parking space. As shown in FIGS. 1, 2, and 3, the non-contact power transmission system 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 power supply box 8 connected to a commercial power source 6, an inverter unit 10, a ground side coil unit 12, a foreign object detection means 14, and a control unit (for example, a microcomputer) 16, and a foreign object The detection means 14 and the control unit 16 constitute a power control device 17. On the other hand, the power receiving device 4 includes a vehicle side coil unit 18, a rectifying unit 20, a battery 22 as a load, and a control unit (for example, a microcomputer) 24.

  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 power source box 8, and the output end of the power source box 8 is connected to the input end of the inverter unit 10. The output end of the unit 10 is connected to the ground side coil unit 12. On the other hand, in the power receiving device 4, the output end of the vehicle side coil unit 18 is connected to the input end of the rectifying unit 20, and the output end of the rectifying unit 20 is connected to the battery 22.

  The ground side coil unit 12 is laid on the ground, and the power supply box 8 is erected at a position separated from the ground side coil unit 12 by a predetermined distance, for example. On the other hand, the vehicle side coil unit 18 is attached to, for example, a vehicle body bottom (for example, a chassis).

  The power feeding device side control unit 16 performs wireless communication with the power receiving device side control unit 24, and the power receiving device side control unit 24 determines a power command value according to the detected remaining voltage of the battery 22, and uses the determined power command value. It transmits to the electric power feeder side control part 16. The power feeding device side control unit 16 compares the power feeding power detected by the ground side coil unit 12 with the received power command value, and drives the inverter unit 10 so that the power command value is obtained.

  During power feeding, the power receiving device side control unit 24 detects the received power and changes the power command value to the power feeding device side control unit 16 so that the battery 22 is not overcurrent or overvoltage.

  As shown in FIG. 2, when power is supplied from the power supply device 2 to the power reception device 4, the vehicle side coil unit 18 is disposed to face the ground side coil unit 12 by appropriately moving the vehicle, and the power supply device side control is performed. When the unit 16 drives and controls the inverter unit 10, a high-frequency electromagnetic field is formed between the ground side coil unit 12 and the vehicle side coil unit 18. The power receiving device 4 takes out electric power from a high frequency electromagnetic field and charges the battery 22 with the taken out electric power.

  The foreign matter detection means 14 is for detecting whether or not foreign matter is present in the high-frequency electromagnetic field region and the vicinity thereof, and is provided, for example, in the ground side coil unit 12 of the power feeding device 2 as shown in FIG. The details of the foreign matter detection means 14 will be described later.

  In the present invention, the term “foreign matter” refers to an object such as a person or object that exists in the high-frequency electromagnetic field region or may invade, and in particular, the temperature may be increased due to an electromagnetic field, causing expansion damage. It is a piece of metal with a gap.

  FIG. 4 is an external top view of the ground side coil unit 12 of the non-contact power transmission system according to the present invention. As shown in FIG. 4, a primary coil 26 is installed inside the cover 29, and a high-frequency electromagnetic field region formed by the primary coil 26 is a detection region 27. The foreign matter detection means 14 includes a sensor coil 28. By installing a plurality of sensor coils 28, it is possible to detect in a wide area of the entire detection area 27 around the cover 29.

  FIGS. 5A and 5B are explanatory diagrams for mutual interference between the coils, and show magnetic fluxes 32 and 33 generated by the primary coil 26 and the sensor coil 28.

  As shown in FIG. 5A, when the magnetic flux 32 generated by the primary coil 26 and the magnetic flux 33 generated by the sensor coil 28 are arranged in parallel, the coupling between the primary coil 26 and the sensor coil 28 increases. For this reason, when the sensor coil 28 receives the magnetic flux 32 or the primary coil 26 receives the magnetic flux 33, problems such as an increase in power supply loss, a rise in temperature of the sensor coil 28, and a decrease in accuracy due to an increase in noise occur. To do.

  On the other hand, as shown in FIG. 5B, when the magnetic flux 32 generated by the primary coil 26 and the magnetic flux 33 generated by the sensor coil 28 are arranged orthogonally, the coupling between the primary coil 26 and the sensor coil 28 becomes small. With such a configuration, mutual interference can be suppressed and detection can be performed with high accuracy.

  FIGS. 6A and 6B are external top views of the ground side coil unit 12 showing an arrangement example of the sensor coils 28. FIG. FIG. 6A is an overall view, and the sensor coil 28 is arranged so as to wind the primary coil 26 and a magnetic material 30 such as ferrite. The sensor coil 28 can obtain an inductance with a small number of turns by winding the magnetic material 30.

FIG. 6B is an enlarged view of the sensor coil 28 portion, and a plurality of sensor coils 28 are arranged side by side in the winding axis direction. By operating so that the magnetic fluxes generated from the adjacent sensor coils 28 are opposite to each other, the magnetic fluxes collide with each other, canceling the winding axis component and moving in the orthogonal direction. Further, it can be directed toward the cover outline near the sensor coil, and the presence of an object (foreign matter) on the cover can be accurately detected in a narrower range.

  Next, foreign object detection and transmission power control will be described with reference to the flowcharts of FIGS. 7 (a) and 7 (b).

  In step S1 of the flowchart shown in FIG. 7A, the vehicle on which the power receiving device 4 is mounted stops so that the coil unit 18 faces the ground side coil unit 12, and the power feeding device side control unit 16 moves to the power receiving device side. A power command value is received from the control unit 24. When the power command value is received, the power supply device side control unit 16 starts the resonance frequency measurement operation by the foreign object detection unit 14 in step S2.

  Thereafter, in step S <b> 3, the power feeding device side control unit 16 instructs the inverter unit 10 to start power transmission, and starts power supply from the ground side coil unit 12 to the vehicle side coil unit 18.

  In step S4, the power supply device side control unit 16 compares the set value with the difference between the detection result of the foreign object detection means 14 (the resonance frequency of the sensor coil 28) and the reference value (the resonance frequency of the sensor coil 28 in the normal state). Determine whether there is a foreign object. If the deviation of the detection result from the reference value exceeds the set value in step S4, it is determined that there is a foreign object, and the process proceeds to step S5 in order to prevent the foreign object from being overheated or damaged by magnetic flux. The foreign matter processing for controlling is performed. In step S4, when the deviation from the reference value of the detection result is equal to or less than the set value, it is determined that there is no foreign matter, the process proceeds to step S6, and the power feeding device side control unit 16 continues power transmission to the inverter unit 10. Let

  The flowchart shown in FIG. 7B shows details of the foreign substance processing in step S5 in the flowchart shown in FIG. In the foreign matter processing, first, in step S21, the presence of the foreign matter is notified by a notification means such as a display or sound. Next, in step S22, the resonance frequency of the sensor coil 28 is measured again, and it is determined whether there is a possibility that foreign matter may cause an expansion damage such as a device failure by comparing the deviation from the reference value and the limit value.

  In step S22, when it is determined that the foreign object causes enlargement damage, the process proceeds to step S23, and the power supply device side control unit 16 transmits the transmission power from the ground side coil unit 12 to the vehicle side coil unit 18 by a predetermined amount. Control is performed to suppress the transmission power, such as reducing to (for example, 1/2) or stopping power transmission. Furthermore, in step S24, a notification means such as a display or a sound notifies that transmission power is being controlled to be suppressed due to the presence of foreign matter.

  On the other hand, when it is determined in step S22 that the foreign matter does not cause the expansion damage, the foreign matter processing is terminated by only bypassing steps S23 and S24 and notifying the possibility of the presence of the foreign matter.

  In step S7 of the flowchart shown in FIG. 7A, if there is an instruction to interrupt power transmission due to the removal of foreign matter by a person or the use of a vehicle, the process proceeds to step S9, and the power supply apparatus side control unit 16 performs an inverter operation. The unit 10 is instructed to end power transmission, the power supply from the ground side coil unit 12 to the vehicle side coil unit 18 is stopped, and the foreign matter detection means 14 ends the detection operation.

  In step S7, when there is no instruction to interrupt power transmission, the process proceeds to step S8, where it is determined whether charging is completed. If charging is not completed, the process returns to step S4, and charging is completed. In step S9, the power supply is terminated and the foreign object detection operation is terminated.

  In the above description, the configuration in which the sensor coil 28 is installed in the ground side coil unit 12 of the power supply apparatus 2 has been described as an example. However, the present invention is not limited to such a case. Instead of such a configuration, for example, a sensor coil may be installed in the vehicle side coil unit 18 of the power receiving device 4. Furthermore, it is good also as a structure which each installed the sensor coil in the ground side coil unit 12 of the electric power feeder 2, and the vehicle side coil unit 18 of the power receiving apparatus 4. FIG.

  Further, in the processing of the flowcharts shown in FIGS. 7A and 7B, the case has been described in which two criteria of the set value and the limit value are provided, and processing such as foreign object detection is performed step by step. With the limit value as a set value, processing such as foreign object detection may be performed based on one criterion.

  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 used in the non-contact power transmission system according to the present invention, it is ensured when a temperature rise occurs due to the presence of a foreign object around the electromagnetic field region during power feeding from the power feeding device to the power receiving device. Therefore, it is useful for a power receiving device and a power feeding device of an electric propulsion vehicle in which a person or an object may approach carelessly or accidentally.

DESCRIPTION OF SYMBOLS 2 Electric power feeder 4 Power receiving device 6 Commercial power supply 8 Power supply box 10 Inverter part 12 Ground side coil unit 14 Foreign material detection means 16 Control part 17 Power control device 18 Vehicle side coil unit 20 Rectification part 22 Battery 24 Control part 26 Primary coil 27 Detection area 28 sensor coil 29 cover 30 magnetic material 32 magnetic flux 33 magnetic flux

Claims (6)

A power supply device that supplies power to a power receiving device in a non-contact manner, a primary coil that generates a magnetic flux by an input alternating current, a cover that covers the primary coil, and a sensor that detects an object present around the cover With a coil,
The power supply device of the non-contact power transmission system in which the winding axis of the sensor coil is configured to be substantially orthogonal to the winding axis of the primary coil. The power supply apparatus for a non-contact power transmission system according to claim 1, wherein a magnetic material such as ferrite is disposed in the vicinity of the primary coil, and the sensor coil is wound around the magnetic material. The power supply apparatus for a non-contact power transmission system according to claim 1, wherein a plurality of the sensor coils are installed, and the sensor coils adjacent in the winding axis direction are set so that the generated magnetic flux is in the reverse direction. A power receiving device that receives power from a power feeding device in a contactless manner, a secondary coil that generates an induced electromotive force by a magnetic flux generated by a primary coil of the power feeding device, a cover that covers the secondary coil, and a periphery of the cover A sensor coil for detecting an object present in the
The power receiving device of the non-contact power transmission system in which the winding axis of the sensor coil is configured to be substantially orthogonal to the winding axis of the secondary coil. The power receiving device of the non-contact power transmission system according to claim 4, wherein a magnetic material such as ferrite is disposed in the vicinity of the secondary coil, and the sensor coil is wound around the magnetic material. The power receiving device of the non-contact power transmission system according to claim 4, wherein a plurality of the sensor coils are installed, and the sensor coils adjacent in the winding axis direction are set so that the generated magnetic flux is in the reverse direction.