Abnormal diagnosis system and abnormal determination method

Abstract

To detect abnormality in a power transmission coil of a power supply device in a simple configuration.SOLUTION: An abnormality diagnostic system 10 comprises: an abnormality determination unit 64 for determining presence or absence of abnormality in a group of power transmission coils 45 arranged in a predetermined area of a road so as to transmit power to a power reception coil 52 of a vehicle 3; and a magnetic field detector 7 for detecting strength of a leakage magnetic field when alternating current magnetic field is radiated from a first power transmission coil that is subject to abnormality determination among the group of power transmitting coils. The abnormality determination unit determines that an abnormality has occurred in the first power transmission coil when an output value of the magnetic field detector is a predetermined threshold value or more, to correct at least one of the output value and the threshold value on the basis of a positional relation between the first power transmission coil and the magnetic field detector.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to an abnormality diagnosis system and an abnormality determination method.

Background Art

[0002] Conventionally, a technique for non-contact power transmission between a power feeding device and a vehicle using a transmission method such as a magnetic resonance method is known (for example, Patent Document 1). By using such a technique, the battery of the vehicle can be charged by non-contact power feeding from the power feeding device to the vehicle.

[0003] Patent Document 1 describes that when power is supplied from a power feeding device to a power receiving device provided in a vehicle, an abnormality of the power receiving device is detected by monitoring the power supplied to the power transmission coil of the power feeding device, and the power supply to the power transmission coil is stopped.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, Patent Document 1 does not consider at all the possibility that an abnormality may occur on the power feeding device side. For example, an abnormality may occur in the power transmission coil due to deterioration or failure of the components constituting the power feeding device, and the intensity of the leakage magnetic field generated around the power transmission coil may exceed a predetermined specified value.

[0006] Therefore, it is desirable to be able to monitor the state of the power transmission coil and detect an abnormality of the power transmission coil at an early stage. However, installing a magnetic field detector such as a magnetic sensor for each of a plurality of power transmission coils provided on a road increases the installation cost.

[0007] Therefore, in view of the above problems, an object of the present invention is to detect an abnormality of a power transmission coil of a power supply device with a simple configuration.

Means for Solving the Problems

[0008] The gist of the present disclosure is as follows.

[0009] (1) An abnormality determination unit that determines the presence or absence of an abnormality of a group of power transmission coils arranged in a predetermined range of a road so as to transmit power to a power reception coil of a vehicle, and a magnetic field detector that detects the intensity of a leakage magnetic field when an alternating magnetic field is radiated from a first power transmission coil that is an abnormality determination target among the group of power transmission coils. The abnormality determination unit determines that an abnormality has occurred in the first power transmission coil when the output value of the magnetic field detector is equal to or greater than a predetermined threshold value, and corrects at least one of the output value and the threshold value based on the positional relationship between the first power transmission coil and the magnetic field detector. An abnormality diagnosis system.

[0010] (2) The magnetic field detector according to the above (1), wherein the magnetic field detector detects, as the intensity of the leakage magnetic field, an electrical characteristic that changes due to an induced current flowing through a second power transmission coil included in the group of power transmission coils and different from the first power transmission coil. Abnormality diagnosis system.

[0011] (3) The abnormality diagnosis system according to the above (2), wherein the electrical characteristic includes a value of an induced current flowing through the second power transmission coil, a value of a voltage generated by the induced current, or a value of another induced current generated by the induced current.

[0012] (4) The abnormality diagnosis system according to the above (2) or (3), wherein the electrical characteristic includes a value of an input current or an output current of an inverter electrically connected to the second power transmission coil.

[0013] (5) The magnetic field detector according to any one of the above (2) to (4), which is provided in a path that is energized when the intensity of the leakage magnetic field is detected by the magnetic field detector and is interrupted when power is supplied to the second power transmission coil. Abnormality diagnosis system.

[0014] (6) When the traffic volume of vehicles in a predetermined range of the road is equal to or greater than a predetermined value, the abnormality determination unit does not determine the presence or absence of an abnormality in the group of power transmission coils. The abnormality diagnosis system according to any one of (1) to (5) above.

[0015] (7) When power is being supplied to a plurality of the power transmission coils in the group of power transmission coils, the abnormality determination unit does not determine the presence or absence of an abnormality in the group of power transmission coils. The abnormality diagnosis system according to any one of (1) to (6) above.

[0016] (8) An abnormality determination method executed by a computer for determining the presence or absence of an abnormality in a group of power transmission coils arranged in a predetermined range of a road so as to transmit power to a power receiving coil of a vehicle. When the output value of a magnetic field detector that detects the intensity of a leakage magnetic field when an alternating magnetic field is radiated from a first power transmission coil that is an abnormality determination target among the group of power transmission coils is equal to or greater than a predetermined threshold value, it is determined that an abnormality has occurred in the first power transmission coil. And correcting at least one of the output value and the threshold value based on the positional relationship between the first power transmission coil and the magnetic field detector. An abnormality determination method.

Effect of the Invention

[0017] According to the present invention, an abnormality in a power transmission coil of a power supply device can be detected with a simple configuration.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

BEST MODE FOR CARRYING OUT THE INVENTION

[0019] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the same reference numerals are assigned to the same components.

[0020] <First Embodiment> Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 to 5.

[0021] First, a configuration for non-contact power supply to a vehicle using a power supply device will be described. FIG. 1 is a diagram schematically showing the configuration of a non-contact power supply system 1. The non-contact power supply system 1 includes a power supply device 2 and a vehicle 3, and performs non-contact power supply between the power supply device 2 and the vehicle 3. In particular, in the present embodiment, the non-contact power supply system 1 performs non-contact power supply from the power supply device 2 to the vehicle 3 by magnetic field resonance coupling (magnetic field resonance) when the vehicle 3 is running. That is, the non-contact power supply system 1 transmits power from the power supply device 2 to the vehicle 3 using a magnetic field as a medium. Note that non-contact power supply is also referred to as non-contact power transmission, wireless power transmission, or wireless power supply.

[0022] The power supply device 2 is configured to perform non-contact power supply to the vehicle 3. Specifically, as shown in FIG. 1, the power supply device 2 includes a power transmission device 4 and a power source 21. In the present embodiment, the power supply device 2 is provided on the road on which the vehicle 3 travels and is embedded, for example, underground (under the road surface). Note that at least a part of the power supply device 2 (for example, the power source 21) may be disposed above the road surface.

[0023] The power source 21 is a power source of the power transmission device 4 and supplies power to the power transmission device 4. The power source 21 is, for example, a commercial AC power source that supplies single-phase AC power. Note that the power source 21 may be an AC power source that supplies three-phase AC power or the like.

[0024] The power transmission device 4 is configured to generate an alternating magnetic field for transmitting power to the vehicle 3. In the present embodiment, the power transmission device 4 includes a power transmission side rectifier circuit 41, an inverter 42, a filter circuit 43, and a power transmission side resonance circuit 44. In the power transmission device 4, appropriate AC power (high-frequency power) is supplied to the power transmission side resonance circuit 44 via the power transmission side rectifier circuit 41 and the inverter 42.

[0025] The power transmission side rectifier circuit 41 is electrically connected to the power source 21 and the inverter 42. The power transmission side rectifier circuit 41 rectifies the AC power supplied from the power source 21 into DC power and supplies the DC power to the inverter 42. The power transmission side rectifier circuit 41 is, for example, an AC / DC converter.

[0026] The inverter 42 is electrically connected to the power transmission side rectifier circuit 41 and the filter circuit 43, and the filter circuit 43 is electrically connected to the inverter 42 and the power transmission side resonance circuit 44. The inverter 42 converts the DC power supplied from the power transmission side rectifier circuit 41 into AC power (high-frequency power) having a frequency higher than that of the AC power of the power source 21 and supplies the high-frequency power to the power transmission side resonance circuit 44 via the filter circuit 43. The filter circuit 43 suppresses harmonic noise generated from the inverter 42.

[0027] The power transmission side resonance circuit 44 has a resonator composed of a power transmission coil 45 and a power transmission side capacitor 46. Various parameters of the power transmission coil 45 and the power transmission side capacitor 46 (such as the outer diameter and inner diameter of the power transmission coil 45, the number of turns of the power transmission coil 45, the capacitance of the power transmission side capacitor 46, etc.) are determined so that the resonance frequency of the power transmission side resonance circuit 44 becomes a predetermined set value. The predetermined set value is, for example, 10 kHz to 100 GHz, and preferably 85 kHz defined by the SAE TIR J2954 standard as the frequency band for non-contact power supply to vehicles.

[0028] The power transmission side resonance circuit 44 is arranged directly below the road surface so that the distance from the road surface is reduced. Also, in the present embodiment, the power transmission side resonance circuit 44 is arranged on the road on which the vehicle 3 travels so that the center of the power transmission coil 45 is located at the center of the lane. When high-frequency power supplied from the inverter 42 is applied to the power transmission side resonance circuit 44, an alternating current flows through the power transmission coil 45 of the power transmission side resonance circuit 44. As a result, the power transmission coil 45 generates an alternating magnetic field for transmitting power to the vehicle 3. In the power transmission device 4, the power source 21 may be a DC power source such as a fuel cell or a solar cell, and in this case, the power transmission side rectifier circuit 41 may be omitted.

[0029] On the other hand, the vehicle 3 is configured to be powered by the power supply device 2 when passing over the power transmission coil 45 provided on the road. Specifically, as shown in FIG. 1, the vehicle 3 includes a power receiving device 5, a motor 31, a battery 32, and a power control unit (PCU) 33. In the present embodiment, the vehicle 3 is a battery electric vehicle (BEV) not equipped with an internal combustion engine, and the motor 31 outputs power for running.

[0030] The motor 31 is an electric motor (for example, an AC synchronous motor), and is driven using the electric power stored in the battery 32 as a power source. The output of the motor 31 is transmitted to the wheels 90 via a speed reducer and an axle. Note that the motor 31 may be a motor generator that functions as an electric motor and a generator. In this case, when the vehicle 3 decelerates, the motor 31 is driven by the rotation of the wheels 90, and the motor 31 generates regenerative power using the deceleration energy of the vehicle 3.

[0031] The battery 32 is a rechargeable secondary battery, and is composed of, for example, a lithium ion battery, a nickel metal hydride battery, or the like. The battery 32 stores electric power and supplies electric power to the electronic devices (for example, the motor 31) of the vehicle 3. When electric power is supplied to the battery 32 from an external power source via the charging port provided in the vehicle 3, the battery 32 is charged and the state of charge (SOC) of the battery 32 is restored.

[0032] The PCU 33 is electrically connected to the battery 32 and the motor 31. The PCU 33 includes an inverter, a boost converter, and a DC / DC converter. The inverter converts the DC power supplied from the battery 32 into AC power and supplies the AC power to the motor 31. The boost converter boosts the voltage of the battery 32 as necessary when the power stored in the battery 32 is supplied to the motor 31. The DC / DC converter steps down the voltage of the battery 32 when the power stored in the battery 32 is supplied to electronic devices such as headlights.

[0033] The power receiving device 5 is configured to receive power via the alternating magnetic field emitted from the power transmitting device 4. In the present embodiment, the power receiving device 5 includes a power receiving side resonance circuit 51, a power receiving side rectifying circuit 54, and a charging circuit 55. The power receiving device 5 receives power from the power transmitting device 4 and supplies the received power to the battery 32.

[0034] The power receiving side resonance circuit 51 is disposed at the bottom of the vehicle 3 so as to reduce the distance from the road surface. In the present embodiment, the power receiving side resonance circuit 51 is disposed at the center of the vehicle 3 in the vehicle width direction and is disposed between the front wheels 90 and the rear wheels 90 in the longitudinal direction of the vehicle 3.

[0035] The power receiving side resonance circuit 51 has the same configuration as the power transmitting side resonance circuit 44 and has a resonator composed of a power receiving coil 52 and a power receiving side capacitor 53. Various parameters of the power receiving coil 52 and the power receiving side capacitor 53 (the outer diameter and inner diameter of the power receiving coil 52, the number of turns of the power receiving coil 52, the capacitance of the power receiving side capacitor 53, etc.) are determined so that the resonance frequency of the power receiving side resonance circuit 51 matches the resonance frequency of the power transmitting side resonance circuit 44. Note that if the deviation amount between the resonance frequency of the power receiving side resonance circuit 51 and the resonance frequency of the power transmitting side resonance circuit 44 is small, for example, if the resonance frequency of the power receiving side resonance circuit 51 is within the range of ±20% of the resonance frequency of the power transmitting side resonance circuit 44, the resonance frequency of the power receiving side resonance circuit 51 does not necessarily have to match the resonance frequency of the power transmitting side resonance circuit 44.

[0036] As shown in FIG. , when the power receiving coil 52 of the power receiving side resonance circuit 51 faces the power transmitting coil 45 of the power transmitting side resonance circuit 44, and an alternating magnetic field is radiated from the power transmitting coil 45, the vibration of the alternating magnetic field is transmitted to the power receiving side resonance circuit 51 that resonates at the same resonance frequency as the power transmitting side resonance circuit 44. As a result, an induced current flows through the power receiving coil 52 of the power receiving side resonance circuit 51 due to electromagnetic induction, and power is generated by the induced current. That is, the power receiving coil 52 receives power from the power transmitting coil 45 provided on the road.

[0037] The power receiving side rectifying circuit 54 is electrically connected to the power receiving side resonance circuit 51 and the charging circuit 55. The power receiving side rectifying circuit 54 rectifies the alternating current power supplied from the power receiving side resonance circuit 51 and converts it into direct current power, and supplies the direct current power to the charging circuit 55. The power receiving side rectifying circuit 54 is, for example, an AC / DC converter.

[0038] The charging circuit 55 is electrically connected to the power receiving side rectifying circuit 54 and the battery 32. The charging circuit 55 converts the DC power supplied from the power receiving side rectifying circuit 54 to the voltage level of the battery 32 and supplies it to the battery 32. When the power transmitted from the power transmission device 4 is supplied to the battery 32 by the power receiving device 5, the battery 32 is charged and the SOC of the battery 32 is restored. The charging circuit 55 is, for example, a DC / DC converter.

[0039] FIG. 2 is a diagram showing an example of a power feeding area where the power transmission coil 45 of the power feeding device 2 is provided. In the example of FIG. 4, five power transmission coils 45 are arranged at intervals along the traveling direction of the vehicle 3 on the same lane of the road. The range on the lane where the power transmission coil 45 is provided corresponds to the power feeding area. Note that the number of power transmission coils 45 provided in the power feeding area may be other numbers.

[0040] When the vehicle 3 reaches the power transmission coil 45 in the power feeding area, power is transmitted from the power transmission coil 45 to the power receiving coil 52 of the vehicle 3. For example, when a power feeding request signal for requesting power feeding from the power feeding device 2 to the vehicle 3 is transmitted from the vehicle 3 to the power feeding device 2 by short-range wireless communication or the like, the power feeding device 2 generates an alternating magnetic field by the power transmission coil 45. As a result, when the vehicle 3 is traveling on the road, the SOC of the battery 32 of the vehicle 3 can be restored by non-contact power feeding from the power feeding device 2 to the vehicle 3.

[0041] However, when an alternating magnetic field is radiated from the power transmission coil 45, a leakage magnetic field is generated, and this leakage magnetic field may have an adverse effect on surrounding electronic devices and the like. For this reason, the power feeding device 2 is designed so that the intensity of the leakage magnetic field generated around the power transmission coil 45 is equal to or less than a predetermined specified value. However, due to deterioration, failure, etc. of the components constituting the power feeding device 2, an abnormality may occur in the power transmission coil 45, and the intensity of the leakage magnetic field may exceed the specified value.

[0042] Therefore, in the present embodiment, in order to detect an abnormality of the power transmission coil 45 at an early stage, the abnormality diagnosis system repeatedly diagnoses the abnormality of the power transmission coil 45. FIG. 3 is a diagram schematically showing an abnormality diagnosis system 10 according to the first embodiment of the present invention. The abnormality diagnosis system 10 includes a controller 6 and a magnetic field detector 7, and diagnoses an abnormality of a group of power transmission coils 45 arranged in a predetermined range of a road so as to transmit power to the power reception coil 52 of the vehicle 3. The group of power transmission coils 45 is, for example, power transmission coils 45 continuously arranged in one power supply area, and in the example of FIG. 3, it consists of five power transmission coils 45.

[0043] The controller 6 is, for example, a general-purpose computer and performs various controls of the power supply device 2. As shown in FIG. 3, the controller 6 includes a memory 61 and a processor 62. The memory 61 and the processor 62 are connected to each other via a signal line. Note that the controller 6 may further include a communication interface or the like for connecting the controller 6 to a communication network such as the Internet.

[0044] The memory 61 has, for example, a volatile semiconductor memory (for example, RAM) and a non-volatile semiconductor memory (for example, ROM). The memory 61 stores a computer program executed in the processor 62, various data used when various processes are executed by the processor 62, and the like.

[0045] The processor 62 has one or more CPUs (Central Processing Unit) and its peripheral circuits, and executes various processes. Note that the processor 62 may further have an arithmetic circuit such as a logical arithmetic unit or a numerical arithmetic unit.

[0046] FIG. 4 is a functional block diagram of the processor 62 of the controller 6. In the present embodiment, the processor 62 includes a power transmission control unit 63 and an abnormality determination unit 64. The power transmission control unit 63 and the abnormality determination unit 64 are functional modules realized by the processor 62 of the controller 6 executing a computer program stored in the memory 61 of the controller 6. Note that the power transmission control unit 63 and the abnormality determination unit 64 may be realized by a dedicated arithmetic circuit provided in the processor 62.

[0047] As shown in FIG. 3, the controller 6 is electrically connected to the inverter 42 of the power transmission device 4, and the power transmission control unit 63 of the controller 6 controls the power transmission from the power transmission coil 45 of the power transmission device 4 to the power reception coil 52 of the vehicle 3 via the inverter 42. In the present embodiment, one inverter 42 is electrically connected to a group of power transmission coils 45, and AC power is supplied from one inverter 42 to each of the group of power transmission coils 45. The power transmission control unit 63 controls the power transmission from the power transmission coil 45 to the power reception coil 52 by controlling the power supply from the inverter 42 to the power transmission coil 45.

[0048] The abnormality determination unit 64 determines the presence or absence of an abnormality in a group of power transmission coils 45 arranged in a predetermined range of the road so as to transmit power to the power reception coil 52 of the vehicle 3. In the present embodiment, the abnormality determination unit 64 determines the presence or absence of an abnormality in a group of power transmission coils 45 based on the output value of the magnetic field detector 7. The magnetic field detector 7 is arranged around the group of power transmission coils 45 and detects the intensity of the leakage magnetic field when an alternating magnetic field is radiated from the power transmission coil 45. The magnetic field detector 7 is configured as a magnetic sensor, and for example, is a magneto-impedance (MI) sensor, a Hall sensor, a magneto resistive (MR) sensor, or the like. As shown in FIG. 3, the magnetic field detector 7 is electrically connected to the controller 6, and the output of the magnetic field detector 7, that is, the intensity of the leakage magnetic field detected by the magnetic field detector 7 is transmitted to the controller 6.

[0049] An example of the arrangement of the magnetic field detector 7 is shown in FIG. 2. The magnetic field detector 7 is arranged near the power supply area of the road, for example, on a sidewalk along the road. In the example of FIG. 2, the magnetic field detector 7 is arranged at the center of a group of power transmission coils 45 arranged in the power supply area in the traveling direction of the vehicle 3. By this, it is possible to avoid an increase in the distance from some of the power transmission coils 45 to the magnetic field detector 7, and it becomes possible to detect the leakage magnetic field of many power transmission coils 45 by one magnetic field detector 7.

[0050] The magnetic field detector 7 detects the intensity of the leakage magnetic field when an alternating magnetic field is radiated from the first power transmission coil to be subjected to abnormality determination among a group of power transmission coils 45. Then, when the output value of the magnetic field detector 7 is equal to or greater than a predetermined threshold value, the abnormality determination unit 64 determines that an abnormality has occurred in the first power transmission coil, and when the output value of the magnetic field detector 7 is less than the threshold value, it determines that no abnormality has occurred in the first power transmission coil.

[0051] However, when determining the presence or absence of an abnormality in a group of power transmission coils 45 using one magnetic field detector 7, the positional relationship between the magnetic field detector 7 and the power transmission coils 45 changes according to the position of each of the group of power transmission coils 45. Therefore, if an abnormality diagnosis is performed using the same determination criteria for different power transmission coils 45, the abnormality determination accuracy decreases.

[0052] Therefore, in the present embodiment, the abnormality determination unit 64 corrects the output value of the magnetic field detector 7 based on the positional relationship between the first power transmission coil to be subjected to abnormality determination and the magnetic field detector 7. By this, it is possible to suppress a decrease in the abnormality determination accuracy due to a change in the positional relationship between the magnetic field detector 7 and the power transmission coils 45, and as a result, it is possible to detect an abnormality in a group of power transmission coils 45 with a simple configuration using one magnetic field detector 7.

[0053] FIG. 5 is a flowchart showing a control routine of the abnormality determination process in the first embodiment. This control routine is repeatedly executed by the processor 62 of the controller 6.

[0054] First, in step S101, the abnormality determination unit 64 determines whether power is being supplied to at least one of the group of power transmission coils 45 based on the power supply status from the inverter 42 to each of the group of power transmission coils 45. If it is determined that power is not being supplied to all of the power transmission coils 45, this control routine ends. On the other hand, if it is determined that power is being supplied to at least one of the power transmission coils 45, this control routine proceeds to step S102.

[0055] In step S102, the abnormality determination unit 64 determines the power transmission coil 45 to which power is being supplied, that is, the power transmission coil 45 that is radiating an alternating magnetic field for power transmission, as the first power transmission coil to be the subject of abnormality determination. When power is being supplied to a plurality of power transmission coils 45, the alternating magnetic field radiated from the power transmission coil 45 closest to the magnetic field detector 7 becomes dominant as the leakage magnetic field detected by the magnetic field detector 7. For this reason, when power is being supplied to a plurality of power transmission coils 45, the abnormality determination unit 64 determines the power transmission coil 45 closest to the magnetic field detector 7 among the power transmission coils 45 to which power is being supplied as the first power transmission coil to be the subject of abnormality determination.

[0056] Next, in step S103, the abnormality determination unit 64 acquires the output value of the magnetic field detector 7, that is, the value of the magnetic field strength detected by the magnetic field detector 7. The output value of the magnetic field detector 7 is acquired, for example, as an average value or a maximum value over a predetermined time.

[0057] Next, in step S104, the abnormality determination unit 64 corrects the output value of the magnetic field detector 7 based on the positional relationship between the first power transmission coil and the magnetic field detector 7. For example, the abnormality determination unit 64 corrects the output value of the magnetic field detector 7 based on the distance between the first power transmission coil and the magnetic field detector 7. In this case, the longer the distance between the first power transmission coil and the magnetic field detector 7, the larger the abnormality determination unit 64 makes the output value of the magnetic field detector 7. For example, the abnormality determination unit 64 corrects the output value of the magnetic field detector 7 by multiplying the output value of the magnetic field detector 7 by a predetermined correction coefficient for each of the group of power transmission coils 45, and the longer the distance between the power transmission coil 45 and the magnetic field detector 7, the larger the correction coefficient is made. Note that the abnormality determination unit 64 may correct the output value of the magnetic field detector 7 in consideration of not only the distance between the first power transmission coil and the magnetic field detector 7 but also the orientation of the first power transmission coil with respect to the magnetic field detector 7 and the like.

[0058] Next, in step S105, the abnormality determination unit 64 determines whether or not the output value of the magnetic field detector 7 corrected in step S104 is equal to or greater than a predetermined threshold value. The threshold value is predetermined such that when the output value of the magnetic field detector 7 is less than the threshold value, the intensity of the leakage magnetic field at a position a predetermined distance away from the power transmission coil 45 radiating the alternating magnetic field is within a predetermined specified value.

[0059] If it is determined in step S105 that the output value of the magnetic field detector 7 is equal to or greater than the threshold value, this control routine proceeds to step S106. In step S106, the abnormality determination unit 64 determines that an abnormality has occurred in the first power transmission coil that is the abnormality determination target. In this case, for example, the power transmission control unit 63 stops the power supply to the power transmission coil 45 in which the abnormality has been determined to have occurred, and prohibits the power supply to this power transmission coil 45 until the abnormality is released. Further, the abnormality determination unit 64 may notify the administrator of the power supply device 2 or the like of the abnormality of the power transmission coil 45 via a communication network such as the Internet. After step S106, this control routine ends.

[0060] On the other hand, when it is determined in step S105 that the output value of the magnetic field detector 7 is less than the threshold value, this control routine proceeds to step S107. In step S107, the abnormality determination unit 64 determines that no abnormality has occurred in the first power transmission coil to be determined for abnormality. In other words, the abnormality determination unit 64 determines that the first power transmission coil to be determined for abnormality is normal. After step S107, this control routine ends.

[0061] In step S104, instead of correcting the output value of the magnetic field detector 7, the abnormality determination unit 64 may correct the threshold value for abnormality determination based on the positional relationship between the first power transmission coil and the magnetic field detector 7. By doing so, it is also possible to suppress a decrease in the abnormality determination accuracy due to a change in the positional relationship between the magnetic field detector 7 and the power transmission coil 45. In this case, the farther the distance between the first power transmission coil and the magnetic field detector 7 is, the smaller the abnormality determination unit 64 makes the threshold value. For example, the abnormality determination unit 64 corrects the threshold value by multiplying the initial value of the threshold value by a correction coefficient predetermined for each of the group of power transmission coils 45, and the farther the distance between the power transmission coil 45 and the magnetic field detector 7 is, the smaller the correction coefficient is. Note that the abnormality determination unit 64 may correct the threshold value in consideration of not only the distance between the first power transmission coil and the magnetic field detector 7 but also the orientation of the first power transmission coil with respect to the magnetic field detector 7 and the like. Further, the abnormality determination unit 64 may correct both the output value of the magnetic field detector 7 and the threshold value based on the positional relationship between the first power transmission coil and the magnetic field detector 7.

[0062] Also, when power is being transmitted to a plurality of the power transmission coils 45 in a group of power transmission coils 45, that is, when an alternating magnetic field is being radiated from a plurality of the power transmission coils 45 in a group of power transmission coils 45, the abnormality determination unit 64 may not determine the presence or absence of an abnormality in the group of power transmission coils 45. By doing so, it is possible to suppress a decrease in the abnormality determination accuracy of the first power transmission coil to be determined for abnormality due to the influence of the alternating magnetic field radiated from the power transmission coils 45 that are not the objects of abnormality determination. In this case, in step S101, the abnormality determination unit 64 determines whether power is being supplied to only one of the power transmission coils 45 in a group of power transmission coils 45.

[0063] <Second Embodiment> The abnormality diagnosis system according to the second embodiment is basically the same as the configuration and control of the abnormality diagnosis system according to the first embodiment, except for the points described below. Therefore, hereinafter, the second embodiment of the present invention will be described centering on the parts different from the first embodiment.

[0064] In the first embodiment, the intensity of the leakage magnetic field when an alternating magnetic field is radiated from the power transmission coil 45 is detected using a magnetic sensor provided separately from the power transmission device 4. On the other hand, in the second embodiment, attention is paid to the fact that an induced current flows through another power transmission coil 45 due to the leakage magnetic field when an alternating magnetic field is radiated from the power transmission coil 45, and the intensity of the leakage magnetic field is detected using a circuit including this other power transmission coil 45.

[0065] FIG. 6 and FIG. 7 are diagrams showing an example of the configuration of the magnetic field detector 7 in the second embodiment. FIGS. 6 and 7 show the circuit of the power transmission device 4 including the inverter 42, the filter circuit 43, and the power transmission side resonance circuit 44. In the example of FIG. 6, the power transmission side capacitor 46 is arranged in series with the power transmission coil 45 in the power transmission side resonance circuit 44, and in the example of FIG. 7, the power transmission side capacitor 46 is arranged in parallel with the power transmission coil 45 in the power transmission side resonance circuit 44.

[0066] For example, the magnetic field detector 7 is a first ammeter 71 that detects the induced current flowing through the power transmission coil 45, and detects the value of the induced current flowing through the power transmission coil 45 as the intensity of the leakage magnetic field. Note that the magnetic field detector 7 may be a voltmeter 72 that detects the voltage across both ends of the power transmission side capacitor 46, and detects the value of the voltage across both ends of the power transmission side capacitor 46, that is, the value of the voltage generated by the induced current, as the intensity of the leakage magnetic field.

[0067] Also, when all the switching elements 421 (e.g., semiconductor switches) of the inverter 42 electrically connected to the power transmission coil 45 via the filter circuit 43 are turned off, when an induced current flows through the power transmission coil 45, a change occurs in the input / output current of the inverter 42 due to the induced current. Therefore, unlike the configuration of FIG. 3, when a separate inverter 42 is provided for each power transmission coil 45, the input / output current of the inverter 42 may be detected as the intensity of the leakage magnetic field. That is, the magnetic field detector 7 may be the second ammeter 73 that detects the output current of the inverter 42, and may detect the value of the output current of the inverter 42 as the intensity of the leakage magnetic field. Also, the magnetic field detector 7 may be the third ammeter 74 that detects the input current of the inverter 42, and may detect the value of the input current of the inverter 42 as the intensity of the leakage magnetic field. Further, the magnetic field detector 7 may be an arbitrary combination of the first ammeter 71, the voltmeter 72, the second ammeter 73, and the third ammeter 74.

[0068] Therefore, in the second embodiment, the magnetic field detector 7 detects, as the intensity of the leakage magnetic field when an alternating magnetic field is radiated from the first power transmission coil, the electrical characteristics that change due to the induced current flowing through the second power transmission coil included in the group of power transmission coils 45 and different from the first power transmission coil to be diagnosed for abnormality. By this, it is possible to detect an abnormality of a group of power transmission coils 45 with a simpler configuration using a circuit including the power transmission coil 45.

[0069] FIG. 8 is a flowchart showing a control routine for abnormality determination processing in the second embodiment. This control routine is repeatedly executed by the processor 62 of the controller 6.

[0070] First, in step S201, similar to step S101 of FIG. 5, the abnormality determination unit 64 determines whether power is being supplied to at least one of the group of power transmission coils 45. If it is determined that power is not being supplied to all the power transmission coils 45, this control routine ends. On the other hand, if it is determined that power is being supplied to at least one of the power transmission coils 45, this control routine proceeds to step S202.

[0071] In step S202, similar to step S102 in FIG. 5, the abnormality determination unit 64 determines the power transmission coil 45 to which power is supplied, that is, the power transmission coil 45 that radiates an alternating magnetic field for power transmission, as the first power transmission coil to be the abnormality determination target.

[0072] Next, in step S203, the abnormality determination unit 64 determines a power transmission coil 45 included in the group of power transmission coils 45 and different from the first power transmission coil as the second power transmission coil for magnetic field detection. For example, the abnormality determination unit 64 determines, in the traveling direction of the vehicle 3, a power transmission coil 45 that is arranged adjacent to, two adjacent to, or three adjacent to the first power transmission coil and to which power is not supplied as the second power transmission coil.

[0073] Next, in step S204, the abnormality determination unit 64 acquires the output value of the magnetic field detector 7, that is, the value of the electrical characteristic that changes due to the induced current flowing through the second power transmission coil. The magnetic field detector 7 is at least one of a first ammeter 71, a voltmeter 72, a second ammeter 73, and a third ammeter 74 provided in a circuit including the second power transmission coil, and the electrical characteristic that changes due to the induced current is at least one of the value of the induced current, the value of the voltage generated by the induced current, the value of the input current of the inverter 42, and the value of the output current of the inverter 42. When a plurality of parameters are acquired as the output value of the magnetic field detector 7, for example, the average value of the plurality of parameters, a value derived from the plurality of parameters by a predetermined calculation formula, etc. are used as the final output value of the magnetic field detector 7.

[0074] After step S204, steps S205 to S208 are executed in the same manner as steps S104 to S107 in FIG. 5. Note that this control routine can be modified in the same manner as the control routine in FIG. 5.

[0075] <Third Embodiment> The abnormality diagnosis system according to the third embodiment is basically the same as the configuration and control of the abnormality diagnosis system according to the second embodiment, except for the points described below. Therefore, hereinafter, the third embodiment of the present invention will be described centering on the parts different from the second embodiment.

[0076] FIG. 9 is a diagram showing an example of the configuration of the magnetic field detector 7 in the third embodiment. FIG. 6 shows the circuit of the power transmission device 4 including the inverter 42, the filter circuit 43, and the power transmission side resonance circuit 44. In the example of FIG. 9, in the power transmission side resonance circuit 44, the power transmission side capacitor 46 is arranged in series with the power transmission coil 45.

[0077] In the third embodiment, the magnetic field detector 7 is provided in a path that is energized when the intensity of the leakage magnetic field is detected by the magnetic field detector 7 and is interrupted when power is supplied to the power transmission coil 45. In this case, a large current or voltage generated when power is supplied to the power transmission coil 45 is not applied to the magnetic field detector 7. Therefore, an ammeter or a voltmeter configured to detect a weak current or voltage caused by the dielectric current can be used as the magnetic field detector 7, and thus the detection accuracy of the leakage magnetic field by the magnetic field detector 7 can be improved.

[0078] For example, the magnetic field detector 7 is a first ammeter 71 that detects the induced current flowing through the power transmission coil 45, and is provided in a path that can be opened and closed by a switching element 441 provided in the power transmission side resonance circuit 44. Note that the magnetic field detector 7 may be a first voltmeter 75 that detects the voltage across both ends of an additional resistor 443 arranged in parallel with the power transmission coil 45 in the power transmission side resonance circuit 44, that is, the voltage generated by the induced current, and is provided in a path that can be opened and closed by a switching element 442 provided in the power transmission side resonance circuit 44.

[0079] Further, the magnetic field detector 7 is the second ammeter 73 that detects the output current of the inverter 42, and may be provided in a path that can be opened and closed by a switching element 422 provided on the output side of the inverter 42. Also, the magnetic field detector 7 is the second voltmeter 76 that detects the voltage across both ends of a resistor 423 additionally provided on the output side of the inverter 42, and may be provided in a path that can be opened and closed by a switching element 424 provided on the output side of the inverter 42. Furthermore, the magnetic field detector 7 is the third ammeter 74 that detects the input current of the inverter 42, and may be provided in a path that can be opened and closed by a switching element 425 provided on the input side of the inverter 42.

[0080] Also, the detection circuit 47 including the detection coil 48 may be provided such that the detection coil 48 is adjacent to the power transmission coil 45 of the power transmission side resonance circuit 44. In this case, the magnetic field detector 7 is the fourth ammeter 77 that detects the induced current flowing through the detection coil 48, that is, another induced current generated by the induced current flowing through the power transmission coil 45, and is provided in a path that can be opened and closed by a switching element 471 provided in the detection circuit 47. Furthermore, the magnetic field detector 7 may be any combination of the first ammeter 71, the first voltmeter 75, the second ammeter 73, the second voltmeter 76, the third ammeter 74, and the fourth ammeter 77.

[0081] In the third embodiment, similar to the second embodiment, the control routine of the abnormality determination process in FIG. 8 is executed. In step S204, the abnormality determination unit 64 acquires the output value of the magnetic field detector 7, that is, the value of the electrical characteristic that changes due to the induced current flowing through the second power transmission coil. The magnetic field detector 7 is at least one of a first ammeter 71, a first voltmeter 75, a second ammeter 73, a second voltmeter 76, a third ammeter 74, and a fourth ammeter 77 as shown in FIG. 9. The electrical characteristic that changes due to the induced current is at least one of the value of the induced current, the value of the voltage generated by the induced current, the value of the input current of the inverter 42, the value of the output current of the inverter 42, and the value of another induced current generated by the induced current flowing through the power transmission coil 45. When a plurality of parameters are acquired as the output value of the magnetic field detector 7, for example, the average value of the plurality of parameters, a value derived from the plurality of parameters by a predetermined calculation formula, etc. are used as the final output value of the magnetic field detector 7.

[0082] <Fourth Embodiment> The abnormality diagnosis system according to the fourth embodiment is basically the same as the configuration and control of the abnormality diagnosis system according to the first embodiment except for the points described below. Therefore, hereinafter, the fourth embodiment of the present invention will be described centering on the parts different from the first embodiment.

[0083] In a state where there are many vehicles traveling in the power supply area where a group of power transmission coils 45 are arranged, when an alternating magnetic field is radiated from the power transmission coil 45 toward the vehicle to be powered, the leakage magnetic field may be blocked by vehicles other than the vehicle to be powered, resulting in a possible decrease in the detection accuracy of the leakage magnetic field. Therefore, in the fourth embodiment, when the traffic volume of vehicles in a predetermined range of the road where a group of power transmission coils 45 are arranged is equal to or greater than a predetermined value, the abnormality determination unit 64 does not determine the presence or absence of an abnormality in the group of power transmission coils 45. By doing so, it is possible to suppress a decrease in the detection accuracy of the leakage magnetic field, and thus further improve the abnormality detection accuracy of the power transmission coil 45.

[0084] FIG. 10 is a flowchart showing a control routine for abnormality determination processing in the fourth embodiment. This control routine is repeatedly executed by the processor 62 of the controller 6.

[0085] First, in step S301, the abnormality determination unit 64 determines whether the traffic volume of vehicles in a predetermined range of the road where a group of power transmission coils 45 are arranged is equal to or greater than a predetermined value. Note that the traffic volume of vehicles in a predetermined range of the road means the number of vehicles passing through the predetermined range of the road within a unit time. For example, the abnormality determination unit 64 acquires the traffic volume of vehicles based on information (such as road traffic information like VICS (registered trademark) information) transmitted from the outside (such as a server) by wired communication or wireless communication. Also, a device capable of detecting vehicles, such as a metal detector, a photoelectric sensor, a camera, or a roadside unit, may be provided on the road, and the abnormality determination unit 64 may acquire the traffic volume of vehicles based on the output of such a device.

[0086] If it is determined in step S301 that the traffic volume of vehicles is equal to or greater than the predetermined value, this control routine ends without determining the presence or absence of an abnormality in the group of power transmission coils 45. On the other hand, if it is determined in step S301 that the traffic volume of vehicles is less than the predetermined value, this control routine proceeds to step S302. Steps S302 to S308 are executed in the same manner as steps S101 to S107 in FIG. 5.

[0087] <Other Embodiments> As described above, the preferred embodiments of the present invention have been explained, but the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the claims. For example, the vehicle 3 powered by the power supply device 2 may be a hybrid vehicle (HEV) or a plug-in hybrid vehicle (PHEV) equipped with an internal combustion engine and a motor as a driving power source.

[0088] Also, even when power supply from the power supply device 2 to the vehicle 3 is not requested, the power transmission control unit 63 may supply power from the inverter 42 to the power transmission coil 45 so that the abnormality determination unit 64 can determine the presence or absence of an abnormality in the power transmission coil 45.

[0089] Also, the above-described embodiments can be implemented in any combination. For example, when the second or third embodiment is combined with the fourth embodiment, in the control routine of FIG. 8, step S301 of FIG. 10 is executed before step S201.

Explanation of Reference Numerals

[0090] 3 Vehicle 6 Controller 62 Processor 64 Abnormality Determination Unit 7 Magnetic Field Detector 10 Abnormality Diagnosis System 45 Power Transmission Coil 52 Power Reception Coil

Claims

1. An abnormality determination unit that determines the presence or absence of an abnormality in a group of power transmission coils arranged in a predetermined range of a road so as to transmit power to a power reception coil of a vehicle; A magnetic field detector that detects the intensity of a leakage magnetic field when an alternating magnetic field is radiated from a first power transmission coil that is a target for abnormality determination among the group of power transmission coils; Comprising; The abnormality determination unit determines that an abnormality has occurred in the first power transmission coil when an output value of the magnetic field detector is equal to or greater than a predetermined threshold value, and corrects at least one of the output value and the threshold value based on the positional relationship between the first power transmission coil and the magnetic field detector. An abnormality diagnosis system.

2. The magnetic field detector detects, as the intensity of the leakage magnetic field, a value of an induced current flowing through a second power transmission coil that is included in the group of power transmission coils and is different from the first power transmission coil, or an electrical characteristic that changes due to the induced current. The abnormality diagnosis system according to claim 1.

3. The electrical characteristic includes a value of a voltage generated by an induced current flowing through the second power transmission coil, or a value of another induced current generated by the induced current. The abnormality diagnosis system according to claim 2.

4. The electrical characteristic includes a value of an input current or an output current of an inverter electrically connected to the second power transmission coil. The abnormality diagnosis system according to claim 2 or 3.

5. The magnetic field detector is provided in a path that is energized when the intensity of the leakage magnetic field is detected by the magnetic field detector and is interrupted when power is supplied to the second power transmission coil. The abnormality diagnosis system according to any one of claims 2 to 4.

6. The abnormality determination unit does not determine the presence or absence of an abnormality in the group of power transmission coils when the traffic volume of vehicles in the predetermined range of the road is equal to or greater than a predetermined value. The abnormality diagnosis system according to any one of claims 1 to 5.

7. The abnormality determination unit does not determine the presence or absence of an abnormality in the group of power transmission coils when power is supplied to a plurality of power transmission coils among the group of power transmission coils. The abnormality diagnosis system according to any one of claims 1 to 6.

8. An abnormality determination method executed by a computer for determining the presence or absence of an abnormality in a group of power transmission coils arranged in a predetermined range of a road so as to transmit power to a power reception coil of a vehicle, When the output value of a magnetic field detector that detects the intensity of a leakage magnetic field when an alternating magnetic field is radiated from a first power transmission coil that is a target for abnormality determination among the group of power transmission coils is equal to or greater than a predetermined threshold value, it is determined that an abnormality has occurred in the first power transmission coil. Correcting at least one of the output value and the threshold value based on the positional relationship between the first power transmission coil and the magnetic field detector An abnormality determination method including the above.

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