JP2023132300A - Abnormality diagnostic system, and abnormality diagnostic method - Google Patents

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

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

BACKGROUND ART Conventionally, there is a known technique for transmitting electric power between a power supply device and a vehicle in a non-contact manner using a transmission method such as a magnetic field resonance method (for example, Patent Document 1). By using such technology, the battery of the vehicle can be charged by contactless power supply from the power supply device to the vehicle.

Patent Document 1 discloses that when power is being supplied from a power feeding device to a power receiving device installed in a vehicle, an abnormality in the power receiving device is detected by monitoring the power supplied to a power transmission coil of the power feeding device, and the power is transmitted. It is stated that the power supply to the coil is stopped.

Japanese Patent Application Publication No. 2013-225962

However, in Patent Document 1, no consideration is given to the possibility that an abnormality may occur on the power supply device side as well. For example, there is a risk that an abnormality may occur in the power transmission coil due to deterioration or failure of components constituting the power supply device, and the strength of the leakage field generated around the power transmission coil may exceed a predetermined specified value.

For this reason, it is desirable to be able to monitor the state of the power transmitting coil and detect abnormalities in the power transmitting coil at an early stage. However, installing a magnetic field detector such as a magnetic sensor for each of the plurality of power transmission coils provided on a road increases installation cost.

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

The gist of the present disclosure is as follows.

(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 area of the road so as to transmit power to the power reception coil of a vehicle, and a a magnetic field detector that detects the strength of a leakage magnetic field when an alternating current magnetic field is radiated from the power transmission coil 1; An abnormality diagnosis system that determines that an abnormality has occurred in the first power transmission coil, 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. .

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

(3) The electrical characteristics include the value of the induced current flowing through the second power transmission coil, the value of the voltage generated by the induced current, or the value of another induced current generated by the induced current, as described in (2) above. Anomaly diagnosis system described in .

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

(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 cut off when power is supplied to the second power transmission coil. The abnormality diagnosis system according to any one of 2) to (4).

(6) The abnormality determination unit does not determine whether or not there is an abnormality in the group of power transmission coils when the amount of vehicle traffic in a predetermined range of the road is equal to or greater than a predetermined value. The abnormality diagnosis system described in (1) above.

(7) The abnormality determining unit does not determine whether there is an abnormality in the group of power transmitting coils when power is being supplied to a plurality of power transmitting coils of the group of power transmitting coils, according to (1) to (6) above. The abnormality diagnosis system according to any one of.

(8) An abnormality determination method that is executed by a computer and determines the presence or absence of an abnormality in a group of power transmitting coils arranged in a predetermined range of a road so as to transmit power to a power receiving coil of a vehicle, the method comprising: If the output value of a magnetic field detector that detects the strength of a leakage magnetic field when an alternating current magnetic field is radiated from the first power transmission coil that is subject to abnormality determination is greater than or equal to a predetermined threshold, An abnormality determination method comprising: determining that an abnormality has occurred; 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.

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

FIG. 1 is a diagram schematically showing the configuration of a contactless power supply system. FIG. 2 is a diagram illustrating an example of a power feeding area in which a power transmission coil of a power feeding device is provided. FIG. 3 is a diagram schematically showing an abnormality diagnosis system according to the first embodiment of the present invention. FIG. 4 is a functional block diagram of the processor of the controller. FIG. 5 is a flowchart showing a control routine for abnormality determination processing in the first embodiment. FIG. 6 is a diagram showing an example of the configuration of the magnetic field detector 7 in the second embodiment. FIG. 7 is a diagram showing an example of the configuration of the magnetic field detector 7 in the second embodiment. FIG. 8 is a flowchart showing a control routine for abnormality determination processing in the second embodiment. FIG. 9 is a diagram showing an example of the configuration of a magnetic field detector in the third embodiment. FIG. 10 is a flowchart showing a control routine for abnormality determination processing in the fourth embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, in the following description, the same reference number is attached to the same component.

<First embodiment>
A first embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

First, a configuration for contactlessly supplying power to a vehicle using a power supply device will be described. FIG. 1 is a diagram schematically showing the configuration of a contactless power supply system 1. As shown in FIG. The contactless power supply system 1 includes a power supply device 2 and a vehicle 3, and performs contactless power supply between the power supply device 2 and the vehicle 3. In particular, in this embodiment, the contactless power supply system 1 performs contactless power supply from the power supply device 2 to the vehicle 3 by magnetic field resonance coupling (magnetic field resonance) while the vehicle 3 is running. That is, the contactless 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 contactless power transfer is also referred to as contactless power transfer, wireless power transfer, or wireless power transfer.

The power supply device 2 is configured to supply power to the vehicle 3 in a non-contact manner. Specifically, as shown in FIG. 1, the power supply device 2 includes a power transmission device 4 and a power source 21. In this 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 portion of the power supply device 2 (for example, the power supply 21) may be placed on the road surface.

The power supply 21 is a power source for the power transmission device 4 and supplies power to the power transmission device 4 . The power supply 21 is, for example, a commercial AC power supply 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.

The power transmission device 4 is configured to generate an alternating magnetic field for transmitting power to the vehicle 3. In this 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 resonant circuit 44. In the power transmission device 4 , appropriate AC power (high frequency power) is supplied to the power transmission side resonant circuit 44 via the power transmission side rectifier circuit 41 and the inverter 42 .

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, converts it 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.

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 resonant circuit 44. The inverter 42 converts the DC power supplied from the power transmission side rectifier circuit 41 into AC power (high frequency power) with a higher frequency than the AC power of the power source 21, and passes the high frequency power to the power transmission side resonance circuit via the filter circuit 43. 44. Filter circuit 43 suppresses harmonic noise generated from inverter 42.

The power transmission side resonant circuit 44 has a resonator including a power transmission coil 45 and a power transmission side capacitor 46. Various parameters of the power transmitting coil 45 and the power transmitting capacitor 46 (outer diameter and inner diameter of the power transmitting coil 45, number of turns of the power transmitting coil 45, capacitance of the power transmitting capacitor 46, etc.) are such that the resonant frequency of the power transmitting side resonant circuit 44 is set to a predetermined value. It is determined to be the set value. The predetermined setting value is, for example, 10 kHz to 100 GHz, and preferably 85 kHz, which is defined by the SAE TIR J2954 standard as a frequency band for wireless power supply of a vehicle.

The power transmission side resonant circuit 44 is arranged directly under the road surface so that the distance from the road surface is small. Further, in this embodiment, the power transmission side resonant circuit 44 is arranged on the road on which the vehicle 3 is traveling so that the center of the power transmission coil 45 is located in the center of the lane. When the high frequency power supplied from the inverter 42 is applied to the power transmission side resonant 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 current magnetic field for transmitting power to the vehicle 3. Note that in the power transmission device 4, the power supply 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.

On the other hand, the vehicle 3 is configured to be supplied with power 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 this embodiment, the vehicle 3 is an electric vehicle (BEV) not equipped with an internal combustion engine, and a motor 31 outputs driving power.

The motor 31 is an electric motor (for example, an AC synchronous motor), and is driven using electric power stored in a battery 32 as a power source. The output of the motor 31 is transmitted to the wheels 90 via a reduction gear 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 is decelerated, 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.

The battery 32 is a rechargeable secondary battery, and includes, 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 electronic equipment (for example, the motor 31) of the vehicle 3. When power is supplied to the battery 32 from an external power source via a charging port provided in the vehicle 3, the battery 32 is charged and the state of charge (SOC) of the battery 32 is restored.

PCU 33 is electrically connected to battery 32 and motor 31. PCU33 has 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 electric 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 electric power stored in the battery 32 is supplied to an electronic device such as a headlight.

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

The power receiving side resonant circuit 51 is arranged at the bottom of the vehicle 3 so that the distance from the road surface is small. Further, in the present embodiment, the power receiving side resonant circuit 51 is arranged at the center of the vehicle 3 in the vehicle width direction, and is arranged between the front wheel 90 and the rear wheel 90 in the longitudinal direction of the vehicle 3.

The power receiving side resonant circuit 51 has the same configuration as the power transmitting side resonant circuit 44 and includes a resonator including 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 (outer diameter and inner diameter of the power receiving coil 52, number of turns of the power receiving coil 52, capacitance of the power receiving side capacitor 53, etc.) are such that the resonance frequency of the power receiving side resonant circuit 51 is on the power transmitting side. It is determined to match the resonant frequency of the resonant circuit 44. Note that if the amount of deviation between the resonant frequency of the power receiving side resonant circuit 51 and the resonant frequency of the power transmitting side resonant circuit 44 is small, for example, the resonant frequency of the power receiving side resonant circuit 51 is ±20% of the resonant frequency of the power transmitting side resonant circuit 44. The resonant frequency of the power receiving side resonant circuit 51 does not necessarily have to match the resonant frequency of the power transmitting side resonant circuit 44 as long as it is within the range.

As shown in FIG. 1, when the power receiving coil 52 of the power receiving side resonant circuit 51 faces the power transmitting coil 45 of the power transmitting side resonant circuit 44, when an alternating current magnetic field is radiated from the power transmitting coil 45, the vibration of the alternating current magnetic field is transmitted to the power receiving side resonant circuit 51 which resonates at the same resonance frequency as the power transmitting side resonant circuit 44 . As a result, an induced current flows through the power receiving coil 52 of the power receiving side resonant circuit 51 due to electromagnetic induction, and electric 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.

The power receiving side rectifier circuit 54 is electrically connected to the power receiving side resonant circuit 51 and the charging circuit 55. The power receiving side rectifier circuit 54 rectifies the AC power supplied from the power receiving side resonant circuit 51, converts it into DC power, and supplies the DC power to the charging circuit 55. The power receiving side rectifier circuit 54 is, for example, an AC/DC converter.

Charging circuit 55 is electrically connected to power receiving side rectifier circuit 54 and battery 32 . The charging circuit 55 converts the DC power supplied from the power receiving rectifier circuit 54 to a voltage level of the battery 32 and supplies the voltage level to the battery 32 . When the power transmitted from the power transmitting 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 recovered. Charging circuit 55 is, for example, a DC/DC converter.

FIG. 2 is a diagram showing an example of a power feeding area in which 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 on the same lane of the road at a distance along the traveling direction of the vehicle 3. The range on the lane in which 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 another number.

When the vehicle 3 reaches the power transmitting coil 45 in the power feeding area, power is transmitted from the power transmitting coil 45 to the power receiving coil 52 of the vehicle 3 . For example, when a power supply request signal requesting power supply from the power supply device 2 to the vehicle 3 is transmitted from the vehicle 3 to the power supply device 2 by short-range wireless communication or the like, the power supply device 2 causes the power transmission coil 45 to generate an alternating current magnetic field. With this, while the vehicle 3 is traveling on the road, the SOC of the battery 32 of the vehicle 3 can be restored by contactless power feeding from the power feeding device 2 to the vehicle 3.

However, when the alternating current 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 supply device 2 is designed so that the strength of the leakage field generated around the power transmission coil 45 is equal to or less than a predetermined value. However, there is a risk that an abnormality may occur in the power transmission coil 45 due to deterioration or failure of the components constituting the power supply device 2, and the strength of the leakage field may exceed a specified value.

Therefore, in this embodiment, the abnormality in the power transmitting coil 45 is repeatedly diagnosed by the abnormality diagnosis system in order to detect the abnormality in the power transmitting coil 45 at an early stage. FIG. 3 is a diagram schematically showing the 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 abnormalities in 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 transmitting coils 45 is, for example, power transmitting coils 45 that are consecutively arranged in one power feeding area, and includes five power transmitting coils 45 in the example of FIG. 3 .

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

The memory 61 includes, for example, a volatile semiconductor memory (eg, RAM) and a nonvolatile semiconductor memory (eg, ROM). The memory 61 stores computer programs executed by the processor 62, various data used when the processor 62 executes various processes, and the like.

The processor 62 includes one or more CPUs (Central Processing Units) and their peripheral circuits, and executes various processes. Note that the processor 62 may further include an arithmetic circuit such as a logical arithmetic unit or a numerical arithmetic unit.

FIG. 4 is a functional block diagram of the processor 62 of the controller 6. In this embodiment, the processor 62 includes a power transmission control section 63 and an abnormality determination section 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 section 63 and the abnormality determination section 64 may be realized by a dedicated arithmetic circuit provided in the processor 62.

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 connects the power transmission coil 45 of the power transmission device 4 to the power receiving coil of the vehicle 3 via the inverter 42. Controls power transmission to 52. In this 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 power transmission from the power transmitting coil 45 to the power receiving coil 52 by controlling power supply from the inverter 42 to the power transmitting coil 45 .

The abnormality determining unit 64 determines whether or not there is an abnormality in a group of power transmitting coils 45 arranged in a predetermined range of the road so as to transmit power to the power receiving coil 52 of the vehicle 3 . In this embodiment, the abnormality determination unit 64 determines whether or not there is an abnormality in the 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 strength of a leakage magnetic field when an alternating current magnetic field is radiated from the power transmission coils 45. The magnetic field detector 7 is configured as a magnetic sensor, and is, for example, a magnetic impedance (MI) sensor, a Hall sensor, a magnetoresistive (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 strength of the leakage magnetic field detected by the magnetic field detector 7, is transmitted to the controller 6.

An example of the arrangement of the magnetic field detector 7 is shown in FIG. The magnetic field detector 7 is placed near the power supply area on 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 feeding area in the traveling direction of the vehicle 3. By this, it is possible to avoid increasing the distance from some of the power transmission coils 45 to the magnetic field detector 7, and it is possible to detect leakage fields from many power transmission coils 45 by one magnetic field detector 7. It becomes possible.

The magnetic field detector 7 detects the strength of a leakage magnetic field when an alternating current magnetic field is radiated from a first power transmitting coil that is a target for abnormality determination among the group of power transmitting coils 45 . Then, the abnormality determination unit 64 determines that an abnormality has occurred in the first power transmission coil when the output value of the magnetic field detector 7 is equal to or higher than a predetermined threshold value, and the output value of the magnetic field detector 7 is equal to or higher than the threshold value. If it is less than that, it is determined that no abnormality has occurred in the first power transmission coil.

However, when determining the presence or absence of an abnormality in a group of power transmitting coils 45 using one magnetic field detector 7, the positional relationship between the magnetic field detector 7 and the power transmitting coils 45 is determined depending on the position of each power transmitting coil 45 in the group. changes. Therefore, if abnormality diagnosis is performed using the same criterion for different power transmission coils 45, the accuracy of abnormality determination will decrease.

Therefore, in this 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 determined as an abnormality and the magnetic field detector 7. By this, it is possible to suppress the deterioration of the abnormality determination accuracy due to a change in the positional relationship between the magnetic field detector 7 and the power transmission coil 45, and furthermore, with a simple configuration using one magnetic field detector 7, a group of Abnormalities in the power transmission coil 45 can be detected.

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

First, in step S<b>101 , the abnormality determination unit 64 determines that at least one power transmission coil 45 of the group of power transmission coils 45 has no power, based on the power supply status from the inverter 42 to each of the power transmission coils 45 of the group. Determine whether it is supplied. If it is determined that power is not being supplied to all power transmitting coils 45, this control routine ends. On the other hand, if it is determined that power is being supplied to at least one power transmission coil 45, the control routine proceeds to step S102.

In step S102, the abnormality determining unit 64 determines the power transmitting coil 45 to which power is being supplied, that is, the power transmitting coil 45 emitting an alternating current magnetic field for power transmission, as the first power transmitting coil to be subjected to abnormality determination. Note that when power is supplied to a plurality of power transmission coils 45, the AC magnetic field radiated from the power transmission coil 45 closest to the magnetic field detector 7 is dominant as the leakage magnetic field detected by the magnetic field detector 7. Become. Therefore, when power is being supplied to a plurality of power transmitting coils 45, the abnormality determining unit 64 determines that the power transmitting coil 45 closest to the magnetic field detector 7 is abnormal among the power transmitting coils 45 to which power is being supplied. It is determined as the target first power transmission coil.

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 intensity detected by the magnetic field detector 7. The output value of the magnetic field detector 7 is obtained, for example, as an average value or a maximum value over a predetermined period of time.

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 abnormality determination unit 64 increases the output value of the magnetic field detector 7 as the distance between the first power transmission coil and the magnetic field detector 7 becomes longer. 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 power transmitting coils 45 in the group, and The longer the distance to the detector 7, the larger the correction coefficient. Note that the abnormality determination unit 64 determines the output of the magnetic field detector 7 by considering not only the distance between the first power transmitting coil and the magnetic field detector 7 but also the orientation of the first power transmitting coil with respect to the magnetic field detector 7. The value may be corrected.

Next, in step S105, the abnormality determination unit 64 determines whether 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 strength of the leakage electromagnetic field at a position a predetermined distance away from the power transmission coil 45 radiating the alternating current magnetic field is within a predetermined value. It will be done.

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, the present 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 to be determined. In this case, for example, the power transmission control unit 63 stops supplying power to the power transmission coil 45 determined to be abnormal, and prohibits power supply to the power transmission coil 45 until the abnormality is resolved. 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.

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

Note that in step S104, the abnormality determination unit 64 corrects the threshold value for abnormality determination based on the positional relationship between the first power transmission coil and the magnetic field detector 7 instead of correcting the output value of the magnetic field detector 7. You may. This also makes it possible to suppress a decrease in 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 abnormality determination unit 64 sets the threshold value smaller as the distance between the first power transmission coil and the magnetic field detector 7 becomes longer. For example, the abnormality determination unit 64 corrects the threshold value by multiplying the initial value of the threshold value by a predetermined correction coefficient for each of the power transmission coils 45 of the group, so that the distance between the power transmission coil 45 and the magnetic field detector 7 is The longer it is, the smaller the correction coefficient is. Note that the abnormality determination unit 64 may correct the threshold value by taking into consideration 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. good. Further, the abnormality determination unit 64 may correct both the output value and the threshold value of the magnetic field detector 7 based on the positional relationship between the first power transmission coil and the magnetic field detector 7.

Further, the abnormality determination unit 64 determines that when power is being transmitted to a plurality of power transmission coils 45 among a group of power transmission coils 45, that is, an alternating current magnetic field is radiated from a plurality of power transmission coils 45 among a group of power transmission coils 45. Sometimes, it is not necessary to determine whether there is an abnormality in the group of power transmitting coils 45. By this, it is possible to suppress a decrease in the abnormality determination accuracy of the first power transmission coil, which is the target of abnormality determination, due to the influence of the alternating current magnetic field radiated from the power transmission coil 45, which is not the target of abnormality determination. In this case, in step S101, the abnormality determination unit 64 determines whether power is being supplied to only one power transmission coil 45 among the group of power transmission coils 45.

<Second embodiment>
The abnormality diagnosis system according to the second embodiment is basically the same in configuration and control as the abnormality diagnosis system according to the first embodiment, except for the points described below. Therefore, the second embodiment of the present invention will be described below, focusing on the differences from the first embodiment.

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

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

For example, the magnetic field detector 7 is a first ammeter 71 that detects the induced current flowing in the power transmitting coil 45, and detects the value of the induced current flowing in the power transmitting coil 45 as the strength of the leakage magnetic field. The magnetic field detector 7 is a voltmeter 72 that detects the voltage across the power transmission capacitor 46, and the value of the voltage across the power transmission capacitor 46, that is, the value of the voltage generated by the induced current, is determined as the strength of the leakage magnetic field. May be detected.

Further, when all switching elements 421 (for example, semiconductor switches) of the inverter 42 electrically connected to the power transmission coil 45 via the filter circuit 43 are turned off, an induced current flows through the power transmission coil 45. Sometimes, 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 strength of the leakage magnetic field. That is, the magnetic field detector 7 is a 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 strength of the leakage magnetic field. Further, the magnetic field detector 7 is a 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 strength of the leakage magnetic field. Furthermore, the magnetic field detector 7 may be any combination of a first ammeter 71, a voltmeter 72, a second ammeter 73, and a third ammeter 74.

Therefore, in the second embodiment, the magnetic field detector 7 has electrical characteristics that change depending on the induced current flowing in the second power transmitting coil that is included in the group of power transmitting coils 45 and is different from the first power transmitting coil that is the target of abnormality diagnosis. is detected as the strength of the leakage magnetic field when the alternating current magnetic field is radiated from the first power transmission coil. This makes it possible to detect abnormalities in the group of power transmitting coils 45 with a simpler configuration using a circuit including the power transmitting coils 45.

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.

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

In step S202, similarly to step S102 in FIG. 1 power transmission coil.

Next, in step S203, the abnormality determining unit 64 determines a power transmitting coil 45 included in the group of power transmitting coils 45 and different from the first power transmitting coil as a second power transmitting coil for magnetic field detection. For example, the abnormality determination unit 64 determines that the power transmission coil 45, which is disposed next to, two or three times next to the first power transmission coil in the traveling direction of the vehicle 3 and to which no power is supplied, is designated as the second power transmission coil. decide.

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 depending on 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 changes depending on the induced current. The electrical characteristic to be determined 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 obtained 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. is the final output of the magnetic field detector 7. value.

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

<Third embodiment>
The abnormality diagnosis system according to the third embodiment is basically the same in configuration and control as the abnormality diagnosis system according to the second embodiment, except for the points described below. Therefore, the third embodiment of the present invention will be described below, focusing on the differences from the second embodiment.

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

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 cut off when power is supplied to the power transmission coil 45. In this case, the large current or voltage that occurs 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 weak currents or voltages caused by dielectric current can be used as the magnetic field detector 7, thereby increasing the accuracy in detecting leakage magnetic fields by the magnetic field detector 7. be able to.

For example, the magnetic field detector 7 is a first ammeter 71 that detects the induced current flowing in 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 resonant circuit 44. The magnetic field detector 7 is a first voltmeter 75 that detects the voltage across the additional resistor 443 arranged in parallel to the power transmitting coil 45 in the power transmitting side resonant circuit 44, that is, the voltage generated by the induced current. , may be provided in a path that can be opened and closed by a switching element 442 provided in the power transmission side resonant circuit 44.

Further, the magnetic field detector 7 is a 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. Further, the magnetic field detector 7 is a second voltmeter 76 that detects the voltage across a resistor 423 additionally provided on the output side of the inverter 42, and is opened/closed by a switching element 424 provided on the output side of the inverter 42. It may be provided along a possible route. Furthermore, the magnetic field detector 7 is a 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.

Further, 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 resonant circuit 44. In this case, the magnetic field detector 7 is a fourth ammeter 77 that detects another induced current generated by the induced current flowing in the detection coil 48, that is, the induced current flowing in the power transmission coil 45, The element 471 provides a path that can be opened and closed. Furthermore, the magnetic field detector 7 is any combination 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. Good too.

In the third embodiment, the control routine of the abnormality determination process shown in FIG. Obtain the values of electrical characteristics that change due to the induced current flowing through the The magnetic field detector 7 includes at least 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. The electrical characteristics that change depending on the induced current are 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 the current flowing in the power transmission coil 45. at least one of the values of another induced current caused by the induced current. When a plurality of parameters are obtained 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. is the final output of the magnetic field detector 7. value.

<Fourth embodiment>
The abnormality diagnosis system according to the fourth embodiment is basically the same in configuration and control as the abnormality diagnosis system according to the first embodiment, except for the points described below. Therefore, the fourth embodiment of the present invention will be described below, focusing on the differences from the first embodiment.

In a state where many vehicles are traveling in a power supply area where a group of power transmission coils 45 are arranged, when an alternating current magnetic field is radiated from the power transmission coil 45 toward the vehicle to which power is being supplied, leakage occurs due to vehicles other than the vehicle to which power is being supplied. Since the magnetic field is cut off, there is a possibility that the detection accuracy of the leakage magnetic field will be reduced. Therefore, in the fourth embodiment, the abnormality determining unit 64 determines whether or not there is an abnormality in the group of power transmitting coils 45 when the amount of vehicle traffic in a predetermined range of the road on which the group of power transmitting coils 45 is arranged is a predetermined value or more. Do not judge. By doing this, it is possible to suppress a decrease in the detection accuracy of the leakage magnetic field, and in turn, it is possible to further improve the abnormality detection accuracy of the power transmission coil 45.

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.

First, in step S301, the abnormality determination unit 64 determines whether the amount of vehicle traffic in a predetermined range of the road on which the group of power transmission coils 45 is arranged is equal to or greater than a predetermined value. Note that the traffic volume of vehicles in a predetermined range of a road means the number of vehicles passing through a predetermined range of a road within a unit time. For example, the abnormality determination unit 64 obtains the vehicle traffic volume based on information (for example, road traffic information such as VICS (registered trademark) information) transmitted from the outside (server, etc.) via wired communication or wireless communication. Further, a device capable of detecting vehicles such as a metal detector, a photoelectric sensor, a camera, or a roadside device is installed on the road, and the abnormality determination unit 64 obtains the traffic volume of vehicles based on the output of such a device. good.

If it is determined in step S301 that the amount of vehicle traffic is equal to or greater than the predetermined value, this control routine ends without determining whether or not there is an abnormality in the group of power transmission coils 45. On the other hand, if it is determined in step S301 that the amount of vehicle traffic is less than the predetermined value, the control routine proceeds to step S302. Steps S302 to S308 are executed in the same manner as steps S101 to S107 in FIG.

<Other embodiments>
Although the preferred embodiments of the present invention have been described above, 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 supplied with power by the power supply device 2 may be a hybrid vehicle (HEV) or a plug-in hybrid vehicle (PHEV) that includes an internal combustion engine and a motor as a driving power source.

Further, even when power feeding from the power feeding device 2 to the vehicle 3 is not requested, the power transmission control unit 63 transmits power from the inverter 42 so that the abnormality determination unit 64 determines whether or not there is an abnormality in the power transmission coil 45. Electric power may be supplied to the coil 45.

Furthermore, the embodiments described above can be implemented in any combination. For example, when the second or third embodiment and the fourth embodiment are combined, in the control routine of FIG. 8, step S301 of FIG. 10 is executed before step S201.

3 Vehicle 6 Controller 62 Processor 64 Abnormality Judgment Unit 7 Magnetic Field Detector 10 Abnormality Diagnosis System 45 Power Transmission Coil 52 Power Receiving Coil

Claims (8)

an abnormality determination unit that determines whether or not there is an abnormality in a group of power transmission coils arranged in a predetermined area of a road so as to transmit power to a power reception coil of a vehicle;
and a magnetic field detector that detects the strength of a leakage magnetic field when an alternating current magnetic field is radiated from a first power transmission coil to be determined as an abnormality 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 higher than a predetermined threshold, and the abnormality determination unit determines that an abnormality has occurred in the first power transmission coil and causes the first power transmission coil and the magnetic field detector to An abnormality diagnosis system that corrects at least one of the output value and the threshold value based on the positional relationship of the output value and the threshold value. The magnetic field detector detects, as the strength of the leakage magnetic field, an electrical characteristic that changes due to an induced current flowing in a second power transmission coil that is included in the group of power transmission coils and is different from the first power transmission coil. The abnormality diagnosis system according to item 1. The abnormality according to claim 2, wherein the electrical characteristics include 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. Diagnostic system. The abnormality diagnosis system according to claim 2 or 3, wherein the electrical characteristics include a value of an input current or an output current of an inverter electrically connected to the second power transmission coil. Claims 2 to 4, wherein 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 cut off when power is supplied to the second power transmission coil. The abnormality diagnosis system according to any one of the above. 6. The abnormality determining unit does not determine whether or not there is an abnormality in the group of power transmission coils when the amount of vehicle traffic in a predetermined range of the road is greater than or equal to a predetermined value. Abnormality diagnosis system. The abnormality determination unit according to any one of claims 1 to 6 does not determine whether there is an abnormality in the group of power transmission coils when power is being supplied to a plurality of power transmission coils among the group of power transmission coils. Described abnormality diagnosis system. An abnormality determination method that is executed by a computer and 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, the method comprising:
When the output value of a magnetic field detector that detects the strength of a leakage magnetic field when an alternating current magnetic field is radiated from the first power transmitting coil targeted for abnormality determination among the group of power transmitting coils is equal to or higher than a predetermined threshold, determining that an abnormality has occurred in the power transmission coil 1;
An abnormality determination method comprising: correcting at least one of the output value and the threshold value based on a positional relationship between the first power transmission coil and the magnetic field detector.

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