WO2015068476A1

WO2015068476A1 - Non-contact power transmission system

Info

Publication number: WO2015068476A1
Application number: PCT/JP2014/074849
Authority: WO
Inventors: 甘利裕作; 中川智明
Original assignee: 本田技研工業株式会社
Priority date: 2013-11-06
Filing date: 2014-09-19
Publication date: 2015-05-14

Abstract

In a non-contact power transmission system (10), the relative position of a foreign object (300) with respect to a power supply unit (80) or power reception unit (100) is detected and the limit value per unit time for power transmission from the power supply unit (80) to the power reception unit (100) is set according to the sum of the magnetic flux of the foreign object (300), which is estimated on the basis of the relative position.

Description

Contactless power transmission system

The present invention relates to a non-contact power transmission system that performs non-contact power transmission from a power feeding unit to a power receiving unit.

In Japanese Patent Laid-Open No. 2012-228121 (hereinafter referred to as “JPＪ2012-228121 A”), even if a foreign object exists between the power transmission coil and the power reception coil, the power supply from the power transmission coil to the power reception coil can be continued. It aims at providing the non-contact electric power feeder which can be performed ([0005], summary). In order to achieve this object, in JP２８2012-228121 A, when foreign matter is detected by the foreign matter detection means, the transmitted power is lowered and the second coil (power transmission coil 16) to the first coil (power receiving coil 26). ) (Summary). In JP 2012-228121 A, foreign matter is detected based on the heat quantity Q of the cooling water for cooling the power transmission coil 16 ([0041], [0058], [0063] to [0064]).

In US Patent Application Publication No. 2011/0270462 (hereinafter referred to as “US「 2011/0270462 A1 ”), when there is an obstacle such as a person or an object, the system can quickly detect this and control the power supply state. And its control method ([0006]). In order to achieve this purpose, in US 2011/0270462 A1, if the transmission efficiency is less than the specified value, there is a possibility that there is an obstacle, so power transmission is temporarily stopped and periodically with a small amount of power. Transmit power to detect efficiency. When the efficiency exceeds the specified value, transmission is resumed with regular power (summary). In US 2011 / 027042４６A1, transmission efficiency is calculated from the transmitted power in the power transmission unit 12 and the received power obtained in the power reception unit 14 ([0053]).

JP 2012-228121 A only determines the transmission power according to the presence or absence of foreign matter, and cannot set the transmission power in detail according to the state of the foreign matter. In JP 2012-228121 A, foreign matter is detected based on the heat quantity Q of the cooling water that cools the power transmission coil 16, and therefore foreign matter cannot be detected unless power is actually transmitted.

In US 2011 / 0270462４６A1, the transmission efficiency is calculated from the transmitted power in the power transmission unit 12 and the received power obtained in the power reception unit 14, and therefore the possibility of an obstacle cannot be determined without actually transmitting power. In addition, although there is no influence on the transmission efficiency, if there is a foreign object that generates excessive heat, the foreign object may have an adverse effect in US 2011 / 0270462４６A1.

The present invention has been made in consideration of the above-described problems, and realizes a new method for setting transmission power in detail, setting transmission power according to a foreign object before transmission, and setting transmission power. An object of the present invention is to provide a non-contact power transmission system capable of at least one of doing.

A non-contact power transmission system according to the present invention transmits power in a non-contact manner from a power feeding unit to a power receiving unit, detects a relative position of a foreign object with respect to the power feeding unit or the power receiving unit, and based on the relative position A limit value of transmission power per unit time from the power feeding unit to the power receiving unit is set according to the estimated total amount of magnetic flux in the foreign matter.

According to the present invention, the limit value per unit time of the transmitted power from the power feeding unit to the power receiving unit is set according to the total amount of magnetic flux in the foreign matter. For this reason, it becomes possible to provide the new method of setting transmission power. Further, the total amount of magnetic flux in the foreign matter affects the amount of heat generated in the foreign matter (and the resulting power loss during power transmission). For this reason, it becomes possible to set transmission power finely according to the calorific value (or power loss) in a foreign object.

Furthermore, according to the present invention, the total amount of magnetic flux in the foreign object is estimated based on the relative position of the foreign object with respect to the power feeding unit and the power receiving unit. For this reason, even before actual power transmission, the total amount of magnetic flux can be estimated. In this case, it is possible to set the transmission power according to the foreign object before power transmission.

A set of plane coordinates in a direction in which one side of the first coil or the second coil is viewed from the other side, with the side surfaces of the solenoid-type first coil for power supply and the second coil for power reception facing each other and contactless. May be used at least as the relative position of the foreign matter. This makes it possible to estimate or calculate the total amount of magnetic flux passing through the foreign matter for the magnetic flux in the direction perpendicular to the central axis direction of the first coil or the second coil. For this reason, in the configuration in which the magnetic flux in the direction has a relatively large influence on the heat generation amount (or power loss) in the foreign material, it is possible to appropriately set the transmission power.

The contactless power transmission system may include an imaging unit that images the foreign matter, and the set of the plane coordinates as the relative position of the foreign matter may be detected based on an image acquired by the imaging unit. Thereby, it is possible to easily detect a set of plane coordinates in a direction in which one of the first coil and the second coil is viewed from the other.

The solenoid-type first coil for power feeding and the second coil for power reception face each other to transmit power in a non-contact manner, and the first coil and the second coil are each a plurality of divided coils connected in parallel. Are arranged in a straight line in the direction of the central axis of the first coil and the second coil, and the power transmission is stopped between the split coils sandwiching the foreign matter therebetween, and the split coil does not sandwich the foreign matter therebetween. Power may be transmitted between. Thereby, power transmission can be performed while suppressing heat generation or power loss in the foreign matter.

At least one of the first coil and the second coil may be wound around a core made of a magnetic material, and the non-energized coil may be used as a magnetic path. As a result, it is possible to suppress leakage magnetic flux and improve power supply efficiency.

A non-contact power transmission system according to the present invention transmits power from a power feeding unit to a power receiving unit in a non-contact manner, detects a relative position of a foreign object with respect to the power feeding unit or the power receiving unit, and receives the power from the power feeding unit. The limit value of the transmission power per unit time to the unit is changed according to the relative position.

1 is a schematic configuration diagram of a contactless power transmission system according to a first embodiment of the present invention. It is a figure which shows arrangement | positioning of the electric power feeder side camera and vehicle side camera in 1st Embodiment. It is a figure which shows the electric circuit regarding the wireless electric power feeding to the vehicle from the electric power feeder in 1st Embodiment. It is a figure which shows the amount of magnetic flux in each of the feeding coil shown simply and the X direction, the Y direction, and the Z direction. FIG. 5A shows an example of the magnetic flux density at the points P1 and P2 in FIG. 4, and FIG. 5B shows an example of the degree of the temperature rise of the foreign matter per unit time at the points P1 and P2. It is a figure which shows when the said foreign material exists in a 1st attitude | position with respect to the said electric power feeding coil. It is a figure which shows when the said foreign material exists in a 2nd attitude | position with respect to the said electric power feeding coil. It is a figure which shows when the said foreign material exists in a 3rd attitude | position with respect to the said electric power feeding coil. It is a flowchart of control of the electric power feeding control apparatus (power feeding apparatus side) and electronic control apparatus (vehicle side) at the time of power transmission of 1st Embodiment. It is a figure which shows an example of the relationship between a chain | linkage area, the temperature rise degree of the foreign material per unit time, and power transmission mode. 10 is a flowchart showing details of power transmission mode determination (S3 to S5 in FIG. 9). It is a figure which shows an example of the magnetic flux amount of the Z direction estimated for every coordinate of the XY direction divided into the matrix form. It is a figure which shows an example of the database which memorize | stored the magnetic flux amount of the Z direction for every coordinate of XY direction. It is a schematic block diagram of the non-contact power transmission system which concerns on 2nd Embodiment of this invention. It is a figure which shows the electric circuit regarding the wireless electric power feeding from the electric power feeder in 2nd Embodiment to a vehicle. It is an external appearance perspective view which shows a part of electric power feeding circuit of the electric power feeder in 2nd Embodiment, and a receiving circuit of a vehicle. It is a flowchart of control of the electric power feeding control apparatus (power feeding apparatus side) and the electronic control apparatus (vehicle side) at the time of power transmission of 2nd Embodiment. It is a figure for demonstrating operation | movement of the feed coil and power receiving coil at the time of power transmission of 2nd Embodiment. It is a figure which shows arrangement | positioning of the pressure sensor and laser displacement meter as a modification of the position detection means of a foreign material.

A. First Embodiment 1. FIG. Configuration [1-1. Overview]
FIG. 1 is a schematic configuration diagram of a contactless power transmission system 10 (hereinafter also referred to as “system 10”) according to the first embodiment of the present invention. As shown in FIG. 1, the system 10 includes a power supply device 12 that supplies power to the outside and a vehicle 14 that receives power supply from the power supply device 12.

[1-2. Power feeding device 12]
As shown in FIG. 1, the power feeding device 12 includes a DC power supply 20, a power transmission inverter 22 (hereinafter also referred to as “inverter 22”), a power feeding circuit 24, a power feeding device side camera 26, and a communication device 28 (hereinafter referred to as “power feeding device”). And a power supply control device 30 (hereinafter also referred to as “control device 30”). Instead of the DC power supply 20 and the inverter 22, an AC power supply may be used.

The inverter 22 converts a direct current from the direct current power source 20 into an alternating current and outputs the alternating current to the power feeding circuit 24. The power feeding circuit 24 outputs the electric power from the inverter 22 to the vehicle 14. Details of the power feeding circuit 24 will be described later with reference to FIG.

FIG. 2 is a diagram illustrating an arrangement of the power supply device side camera 26 and a vehicle side camera 54 described later in the first embodiment. In FIG. 2, the case where it parks from the front side of the vehicle 14 is shown. The power supply device side camera 26 (hereinafter also referred to as “first camera 26” or “camera 26”) is disposed on the far side of the parking space with respect to the power supply coil 80 (described later) of the power supply circuit 24. Images in the peripheral width direction (Y direction) and height direction (Z direction) (hereinafter also referred to as “YZ image Iyz”) are acquired. As will be described later, another component (position detecting means) may be used instead of the first camera 26.

The communication device 28 is used for wireless communication with the vehicle 14.

The control device 30 controls the inverter 22 and the power feeding circuit 24 via the communication line 32 (FIG. 1). At that time, the control device 30 communicates with the vehicle 14 via the communication device 28. The control device 30 includes an input / output unit 34 as an input / output interface, a calculation unit 36 that performs various calculations, and a storage unit 38 that stores programs and data used by the calculation unit 36.

[1-3. Vehicle 14]
(1-3-1. Overall configuration)
The vehicle 14 is a so-called electric vehicle having a travel motor 40 (hereinafter also referred to as “motor 40”) as a drive source. As will be described later, the vehicle 14 may be an electric vehicle such as a hybrid vehicle having an engine in addition to the motor 40.

In addition to the traveling motor 40, the vehicle 14 includes a motor driving inverter 42 (hereinafter also referred to as “inverter 42”), a battery 44 (power storage device), a voltage sensor 46, a current sensor 48, an SOC sensor 50, The power receiving circuit 52, the vehicle-side camera 54, a communication device 56 (hereinafter also referred to as “vehicle-side communication device 56”), and an electronic control device 58 (hereinafter referred to as “ECU 58”). A DC / DC converter (not shown) may be arranged between the inverter 42 and the battery 44 to transform the output voltage of the battery 44.

(1-3-2. Motor 40 and inverter 42)
The motor 40 of the first embodiment is a three-phase AC brushless type. The motor 40 generates a driving force based on the electric power supplied from the battery 44, and rotates wheels (not shown) through a transmission (not shown) by the driving force. Further, the motor 40 outputs electric power (regenerative power Preg) [W] generated by performing regeneration to the battery 44 or the like.

The inverter 42 has a three-phase bridge type configuration and performs DC-AC conversion. More specifically, the inverter 42 converts direct current into three-phase alternating current and supplies it to the motor 40, while supplying direct current after alternating current-direct current conversion accompanying the regenerative operation to the battery 44 and the like.

(1-3-3. Battery 44, voltage sensor 46, current sensor 48 and SOC sensor 50)
The battery 44 is a power storage device (energy storage) including a plurality of battery cells, and for example, a lithium ion secondary battery, a nickel hydride secondary battery, or a capacitor can be used. In the first embodiment, a lithium ion secondary battery is used.

The voltage sensor 46 detects an input voltage (hereinafter referred to as “battery input voltage Vbat” or “voltage Vbat”) [V] from the power receiving circuit 52 to the battery 44. The current sensor 48 detects an input current (hereinafter referred to as “battery input current Ibat” or “current Ibat”) [A] from the power receiving circuit 52 to the battery 44. The SOC sensor 50 detects the remaining capacity (SOC) [%] of the battery 44.

(1-3-4. Power receiving circuit 52)
The power receiving circuit 52 receives power from the power feeding device 12 and charges the battery 44. Details of the power receiving circuit 52 will be described later with reference to FIG.

(1-3-5. Vehicle-side camera 54)
As shown in FIG. 2, the vehicle-side camera 54 (hereinafter also referred to as “second camera 54” or “camera 54”) is disposed at the bottom (under the floor) of the vehicle 14 (vehicle body) so as not to interfere with the feeding coil 80. Then, the lower part of the vehicle 14 is imaged and output to the ECU 58. The images acquired by the second camera 54 are images in the front-rear direction (X direction) and the width direction (Y direction) of the power feeding coil 80 and its surroundings, and are also referred to as “XY images Ixy” below. Note that when the second camera 54 is disposed obliquely with respect to the power supply coil 80, an image from the second camera 54 may be processed by the ECU 58 or the like to generate the XY image Ixy. As will be described later, another component (position detecting means) may be used instead of the second camera 54.

(1-3-6. Communication device 56)
The communication device 56 is used for wireless communication with the power supply device 12.

(1-3-7. ECU58)
The ECU 58 controls the motor 40, the inverter 42, the battery 44, and the power receiving circuit 52 via the communication line 60 (FIG. 1). Further, the ECU 58 communicates with the power supply device 12 via the communication device 56 to control power transmission (power supply) from the power supply device 12. At that time, the ECU 58 uses detection values of various sensors such as the voltage sensor 46, the current sensor 48, and the SOC sensor 50.

The ECU 58 includes an input / output unit 62 as an input / output interface, a calculation unit 64 that performs various calculations, and a storage unit 66 that stores programs and data used by the calculation unit 64. The ECU 58 is not limited to only one ECU, but can be configured from a plurality of ECUs for each of the motor 40, the inverter 42, the battery 44, and the power receiving circuit 52.

[1-4. Electric circuit for wireless power feeding]
FIG. 3 is a diagram illustrating an electric circuit related to wireless power feeding from the power feeding device 12 to the vehicle 14 in the first embodiment.

(1-4-1. Power feeding device 12)
As described above, the power supply device 12 includes the DC power supply 20, the inverter 22, and the power supply circuit 24. As shown in FIG. 3, a smoothing capacitor 70 is disposed between the DC power supply 20 and the inverter 22.

The inverter 22 has a full bridge configuration including four switching elements 72, converts a direct current from the direct current power source 20 into an alternating current, and outputs the alternating current to the power feeding circuit 24. The power feeding control device 30 controls each switching element 72.

The power feeding circuit 24 outputs the electric power from the inverter 22 to the vehicle 14. As shown in FIG. 3, the power supply circuit 24 includes a power supply coil 80 (hereinafter also referred to as “coil 80”) and a capacitor 82. The coil 80 is a so-called solenoid coil (tubular coil). In the power feeding circuit 24, the coil 80 and the capacitor 82 are connected in parallel to form an LC circuit 84. The coil 80 and the capacitor 82 may be connected in series. A switch 86 controlled by the control device 30 is disposed between the LC circuit 84 and the inverter 22.

(1-4-2. Vehicle 14)
As described above, the vehicle 14 includes the battery 44 and the power receiving circuit 52. As shown in FIG. 3, a smoothing capacitor 90 is disposed between the battery 44 and the power receiving circuit 52. In FIG. 3, the voltage sensor 46, the current sensor 48, and the SOC sensor 50 are omitted.

The power receiving circuit 52 receives power from the power feeding device 12 and charges the battery 44. As shown in FIG. 3, the power receiving circuit 52 includes a power receiving coil 100 (hereinafter also referred to as “coil 100”) and a capacitor 102. The coil 100 is a so-called solenoid coil (tubular coil). In the power receiving circuit 52, the coil 100 and the capacitor 102 are connected in parallel to form the LC circuit 104. Note that the coil 100 and the capacitor 102 may be connected in series. A rectifier circuit 106 and a switch 108 are disposed between the LC circuit 104 and the battery 44 and the smoothing capacitor 90.

2. Power supply control [2-1. basic way of thinking]
In the first embodiment, when a foreign object 300 (FIG. 2) enters between the power feeding coil 80 and the power receiving coil 100, the transmitted power from the power feeding coil 80 to the power receiving coil 100 is limited. However, depending on the state of the foreign object 300, there is a case where the restriction may not be performed, so such a case is determined. Specifically, in the first embodiment, the transmission power is limited in consideration of the total amount of magnetic flux Φt in the foreign material 300. The total amount of magnetic flux Φt is determined according to the magnetic flux density B and the interlinkage area A.

(2-1-1. Magnitude of magnetic flux Φ (difference in temperature rise due to relative position))
FIG. 4 is a diagram showing the power supply coil 80 shown in a simplified manner and the amount of magnetic flux Φ in each of the X direction, the Y direction, and the Z direction. Hereinafter, the magnetic flux amount Φ in each of the X direction, the Y direction, and the Z direction is also referred to as Φx, Φy, and Φz. 5A shows an example of the magnetic flux density B at the points P1 and P2 in FIG. 4, and FIG. 5B shows an example of the degree of temperature rise ΔT [° C./sec] of the foreign matter 300 per unit time at the points P1 and P2. . The magnetic flux density B in FIG. 5A is a composite value of the magnetic flux densities Bx, By, Bz in the X direction, the Y direction, and the Z direction.

As shown in FIG. 4, the magnetic flux amounts Φx, Φy, and Φz in the X direction, the Y direction, and the Z direction change depending on the position with respect to the feeding coil 80. For example, the magnetic flux amount Φz in the Z direction increases and the magnetic flux amount Φx in the X direction decreases at the end in the front-rear direction (X direction). On the other hand, near the center in the front-rear direction (X direction), the magnetic flux amount Φx in the X direction increases, and the magnetic flux amounts Φy, Φz in the Y direction and Z direction decrease. As a result, the temperature rise degree ΔT varies depending on the relative position of the foreign object 300 with respect to the power supply coil 80 (FIG. 5B).

(2-1-2. Size of interlinkage area A (difference in temperature rise due to shape or posture))
6 to 8 are diagrams showing the foreign object 300 in the first to third postures with respect to the feeding coil 80. FIG. The foreign material 300 here has a rectangular parallelepiped shape (in particular, a thin plate shape). In the first posture (FIG. 6), the linkage area A in the Z direction (hereinafter referred to as “linkage area Az”) is the largest, and the linkage area A in the X direction (hereinafter referred to as “linkage area Ax”). Is the smallest. In the second posture (FIG. 7), the interlinkage area Ax in the X direction is the largest, and the interlinkage area A in the Y direction (hereinafter referred to as “interlinkage area Ay”) is the smallest. In the third posture (FIG. 8), the interlinkage area Ay in the Y direction is the largest, and the interlinkage area Az in the Z direction is the smallest.

6 to 8, the foreign object 300 is located around the end portion of the feeding coil 80 in the X direction. As described with reference to FIG. 4, the magnetic flux amount Φz in the Z direction increases and the magnetic flux amount Φx in the X direction decreases near the end in the X direction.

In the case of the first posture (FIG. 6), the interlinkage area Az in the Z direction of the foreign material 300 is the largest. In the second posture (FIG. 7), the interlinkage area Az in the Z direction of the foreign material 300 is intermediate between the interlinkage areas Ax and Ay in the X direction and the Y direction. In the case of the third posture (FIG. 8), the interlinkage area Az in the Z direction of the foreign material 300 is the smallest. If the magnetic flux density Bz in the Z direction of the foreign material 300 is assumed to be equal, the foreign material 300 in the first posture (FIG. 6) is most likely to become the highest temperature.

Further, when the foreign object 300 is present near the center of the feeding coil 80 in the X direction with the first to third postures, the degree of temperature rise ΔT is different. That is, the magnetic flux amount Φx in the X direction among the XYZ directions is the largest in the vicinity of the center of the feeding coil 80 in the X direction. For this reason, when the magnetic flux density Bx of the X direction in the foreign material 300 is equal, the foreign material 300 in a 2nd attitude | position (FIG. 7) tends to become the highest temperature.

(2-1-3. Calculation of total magnetic flux Φt)
As described above, even with the same foreign object 300, the degree of temperature rise changes according to the posture (orientation) or the interlinkage area A in each direction (in other words, according to the total amount Φt of magnetic fluxes). Therefore, in the first embodiment, the transmission power is limited according to the total amount of magnetic flux Φt.

[2-2. Overall flow]
FIG. 9 is a flowchart of control of the power supply control device 30 (power supply device 12 side) and the ECU 58 (vehicle 14 side) during power transmission according to the first embodiment. The control device 30 is already in the standby state before starting the control of FIG.

In step S1 of FIG. 9, the ECU 58 determines whether or not there is a request (external charging request) to charge the battery 44 from the power feeding device 12. For example, an external charging request is issued when an operation button (not shown) of the vehicle 14 is pressed by the user of the vehicle 14 or when a predetermined operation is performed by the user on the touch panel (not shown) of the vehicle 14. Can be determined.

If there is no external charging request (S1: NO), step S1 is repeated. When there is an external charging request (S1: YES), in step S2, the ECU 58 determines whether or not the foreign object 300 exists between the power feeding coil 80 and the power receiving coil 100. The determination is made based on, for example, the YZ image Iyz from the power supply device side camera 26 and the XY image Ixy from the vehicle side camera 54. Alternatively, the determination can be made based only on one of the YZ image Iyz and the XY image Ixy. In the first embodiment, the material of the foreign material 300 is not discriminated, and it is assumed that the foreign material is a foreign material under severe conditions (in other words, the relative dielectric constant is relatively high).

When the foreign object 300 exists (S2: YES), in step S3, the ECU 58 determines that the total amount Φtx, Φty, and Φtz of the respective magnetic flux amounts in the X, Y, and Z directions between the power feeding coil 80 and the power receiving coil 100 is the specified value THtk. , THty, THtz (upper limit value). Details of the determination will be described later with reference to FIG.

If no foreign object 300 exists in step S2 (S2: NO), or if the total amount of magnetic fluxes Φtx, Φty, Φtz is within the specified values THtx, THty, THtz in step S3 (S3: YES), in step S4, The ECU 58 selects the normal mode as the power transmission mode. On the other hand, if any of the total magnetic flux amounts Φtx, Φty, and Φtz is not within the specified values THtx, THty, and THtz in step S3 (S3: NO), in step S5, the ECU 58 selects the output restriction mode as the power transmission mode. To do.

FIG. 10 is a diagram illustrating an example of the relationship between the interlinkage area A, the degree of temperature rise ΔT of the foreign object 300 per unit time, and the power transmission mode. As shown in FIG. 10, when the magnetic flux density B in the foreign material 300 is constant, as the interlinkage area A increases, the total amount of magnetic flux Φt increases and the temperature rise degree ΔT increases.

Therefore, in the first embodiment, when any of the total magnetic flux amounts Φtx, Φty, and Φtz is not within the specified values THtx, THty, and THtz, the supply power per unit time is limited by switching from the normal mode to the output limit mode. Then, the degree of temperature rise ΔT is reduced (see arrow 200 in FIG. 10). As a result, if the original power supply is maintained, the power transmission can be continued in a state where the power supply is reduced where the foreign object 300 is overheated and the power transmission should be stopped.

In step S6 of FIG. 9, the ECU 58 notifies the control device 30 of the selected power transmission mode (normal mode or output restriction mode) and makes a power transmission request to the control device 30. Accordingly, the ECU 58 turns on the switch 108 (FIG. 3) to charge the battery 44.

In subsequent step S <b> 7, the ECU 58 determines whether or not to end the charging of the battery 44 with the electric power from the power feeding device 12. This determination is made, for example, based on whether or not the SOC of the battery 44 has reached a predetermined threshold value (hereinafter referred to as “charging completion threshold value THsoc” or “SOC threshold value THsoc”).

When the charging of the battery 44 is not terminated (S7: NO), the process returns to step S2. Alternatively, simply repeat step S7. When the charging of the battery 44 is to be terminated (S7: YES), in step S8, the ECU 58 notifies the control device 30 that the charging should be terminated, and the current process is terminated. At this time, the ECU 58 turns off the switch 108.

Upon receiving the power transmission mode notification (S6) from the ECU 58, the control device 30 performs power transmission according to the power transmission mode (S11). Specifically, when the normal mode is notified, the control device 30 transmits power in the normal mode, and when the output restriction mode is notified, the control device 30 transmits power in the output restriction mode. Compared to the normal mode, in the output restriction mode, the amount of power per unit time supplied from the feeding coil 80 to the receiving coil 100 is restricted. Thereby, even if the foreign material 300 exists between the power feeding coil 80 and the power receiving coil 100, it is possible to prevent the foreign material 300 from being heated excessively.

Specifically, the control device 30 turns on the switch 86 (FIG. 3). The control device 30 controls the inverter 22 to convert the direct current from the direct current power source 20 into an alternating current, and then supplies (powers) the power receiving coil 100 via the power supply coil 80. Thereby, the battery 44 is charged.

Note that the electric power output from the power supply device 12 to the vehicle 14 in the output restriction mode is set according to the interlinkage area A in each of the XYZ directions so that the degree of temperature rise ΔT of the foreign object 300 per unit time is not more than a predetermined value. (See FIG. 10).

Next, in step S12, the control device 30 determines whether or not to end the power supply. This determination is made based on whether or not notification (S8) that power supply should be terminated has been received from the ECU 58 of the vehicle 14. When the power feeding is not finished (S12: NO), the process returns to step S11. When the power supply is terminated (S12: YES), the current power supply is terminated.

[2-3. Determination of power transmission mode]
FIG. 11 is a flowchart showing details of determination of the power transmission mode (S3 to S5 in FIG. 9). In step S21, the ECU 58 uses the XY image Ixy from the vehicle-side camera 54 to determine the length Lx (depth) in the X direction and the length Ly (width) in the Y direction of the foreign material 300 and the position coordinates C of the foreign material 300. And detect. The lengths Lx and Ly can be, for example, any one of a maximum value, an average value, and a median value. The position coordinates C here are, for example, a coordinate group (XY coordinate group) occupied by the foreign object 300 when viewed from the Z direction.

In step S22, the ECU 58 detects the length Lz (height) of the foreign object 300 in the Z direction and the position coordinate C of the foreign object 300 using the YZ image Iyz from the power supply device side camera 26. The length Lz can be, for example, any one of a maximum value, an average value, and a median value. The position coordinates C here are, for example, a coordinate group (a coordinate group in the YZ direction) occupied by the foreign object 300 when viewed from the X direction. Based on the position coordinates C (coordinate group viewed from the X direction and the Z direction) in steps S21 and S22, the position coordinate C (coordinate group of the XZ direction) viewed from the Y direction can also be calculated. The lengths Lx, Ly, Lz and the position coordinates C may be any as long as they can calculate the total magnetic flux amounts Φtx, Φty, Φtz in steps S24, S26, and S28.

In step S23, the ECU 58 calculates the interlinkage areas Ax, Ay, Az in the X direction, the Y direction, and the Z direction. Specifically, the interlinkage area Ax is obtained by multiplying the length Ly in the Y direction by the length Lz in the Z direction. The interlinkage area Ay is obtained by multiplying the length Lx in the X direction by the length Lz in the Z direction. The interlinkage area Az is obtained by multiplying the length Lx in the X direction and the length Ly in the Y direction. The interlinkage areas Ax, Ay, Az may be obtained by other methods. For example, it is also possible to detect the edge (contour) of the foreign object 300 in each of the XY image Ixy and the YZ image Iyz and obtain the interlinkage areas Ax, Ay, Az based on the number of coordinates included in the edge (contour). It is.

In step S24, the ECU 58 calculates the sum Φtz of the amount of magnetic flux Φz in the Z direction occupying the interlinkage area Az in the Z direction. In the first embodiment, the X-direction, Y-direction, and Z-direction coordinates are divided into a matrix, and a database storing the magnetic flux amount Φ (or magnetic flux density B) for each coordinate is created.

FIG. 12 is a diagram illustrating an example of the amount of magnetic flux Φz in the Z direction estimated for each coordinate (Xn, Yn) in the XY direction divided into a matrix. FIG. 13 is a diagram illustrating an example of a database that stores the amount of magnetic flux Φz in the Z direction for each coordinate (Xn, Yn) in the XY directions. In FIG. 12 and FIG. 13, since the magnetic flux amount Φz in the Z direction is stored for each coordinate (Xn, Yn) in the XY directions, this is synonymous with storing the magnetic flux density Bz in the Z direction as a result. Further, this database stores the amount of magnetic flux Φy in the Y direction for each coordinate (Xn, Zn) in the XZ direction, and stores the amount of magnetic flux Φx in the X direction for each coordinate (Yn, Zn) in the YZ direction. . The database in the first embodiment is stored in the storage unit 66 of the ECU 58.

In the first embodiment, the lengths Lx and Ly and the position coordinates C are detected in step S21. With these numerical values, it is possible to specify the coordinate group occupied by the foreign object 300 in the Z direction. Therefore, the ECU 58 calculates the total Φtz by integrating the magnetic flux amount Φz in the Z direction corresponding to each coordinate included in the coordinate group.

In step S25, the ECU 58 determines whether the total magnetic flux amount Φtz calculated in step S24 is equal to or less than a specified value THtz. The specified value THtz is a threshold value used for selecting the normal mode or the output restriction mode. When the total amount Φtz of the magnetic flux amounts is equal to or less than the specified value THtz (S25: YES), the process proceeds to step S26.

In step S26, the ECU 58 calculates the sum Φty of the amount of magnetic flux Φy in the Y direction occupying the interlinkage area Ay in the Y direction. This process can be performed in the same manner as in step S24. That is, the coordinate group (the coordinate group in the XZ direction) occupied by the foreign object 300 in the Y direction is specified by the lengths Lx, Lz and the position coordinates C detected in steps S21 and S22. Then, the ECU 58 calculates the total Φty by integrating the amount of magnetic flux Φy in the Y direction corresponding to each coordinate included in the coordinate group.

In step S27, the ECU 58 determines whether or not the total magnetic flux amount Φty calculated in step S26 is equal to or less than a specified value THty. The specified value THty is a threshold value used for selecting the normal mode or the output restriction mode. When the total amount Φty of the magnetic flux is equal to or less than the specified value THty (S27: YES), the process proceeds to step S28.

In step S28, the ECU 58 calculates the sum Φtx of the magnetic flux amount Φx in the X direction occupying the interlinkage area Ax in the X direction. This process can be performed in the same manner as steps S24 and S26.

In step S29, the ECU 58 determines whether the total magnetic flux amount Φtx calculated in step S28 is equal to or less than a specified value THtx. The specified value THtx is a threshold value used for selecting the normal mode or the output restriction mode. When the total amount Φtx of the magnetic flux amount is equal to or less than the specified value THtx (S29: YES), in step S30, the ECU 58 selects the normal mode as the power transmission mode.

If the total flux amount Φtz is not less than or equal to the specified value THtz in step S25 (S25: NO), if the total flux amount Φty is not less than or equal to the defined value THty in step S27 (S27: NO), or if the total flux amount Φtz in step S29. Is not less than the specified value THtx (S29: NO), in step S31, the ECU 58 selects the output restriction mode as the power transmission mode.

3. Effects of the First Embodiment As described above, according to the first embodiment, the unit from the power feeding coil 80 (power feeding unit) to the power receiving coil 100 (power receiving unit) according to the total amount Φt of the magnetic flux in the foreign material 300. A limit value of transmission power per hour is set (FIGS. 9 and 11). For this reason, it becomes possible to provide the new method of setting transmission power. In addition, the total amount Φt of the magnetic flux in the foreign object 300 affects the amount of heat generated in the foreign object 300 (and the resulting power loss during power transmission). For this reason, it becomes possible to set transmission power finely according to the calorific value (or power loss) in the foreign material 300.

Furthermore, according to the first embodiment, the total amount Φt of the magnetic flux in the foreign object 300 is estimated based on the relative position of the foreign object 300 with respect to the feeding coil 80 and the power receiving coil 100 (see FIGS. 12 and 13). For this reason, even before actual power transmission, the total amount Φt of the magnetic flux can be estimated. In this case, the transmission power corresponding to the foreign object 300 can be set before power transmission.

In the first embodiment, power is supplied in a contactless manner with the side surfaces of the solenoid-type power supply coil 80 (first power supply coil) and the power receiving coil 100 (second power receiving coil) facing each other (see FIG. 2). In addition, as a relative position of the foreign object 300, at least a set of plane coordinates in a direction (Z direction) when the power feeding coil 80 is viewed from the power receiving coil 100 is used (see FIGS. 12 and 13). As a result, it is possible to estimate the total amount Φt of the magnetic flux passing through the foreign object 300 for the magnetic flux in the direction (Z direction) perpendicular to the central axis direction of the power feeding coil 80 or the power receiving coil 100. For this reason, in the configuration in which the magnetic flux in the Z direction has a relatively large influence on the heat generation amount (or power loss) in the foreign material 300, it is possible to appropriately set the transmission power.

The system 10 according to the first embodiment includes a vehicle-side camera 54 (imaging unit) that images the foreign object 300, and a set of plane coordinates in the Z direction as a relative position of the foreign object 300 is obtained by an XY image Ixy acquired by the camera 54. (See FIGS. 12 and 13). Thereby, it becomes possible to easily detect a set of plane coordinates in the direction (Z direction) when the power feeding coil 80 is viewed from the power receiving coil 100.

B. Second Embodiment 1. FIG. Configuration [1-1. Overview]
FIG. 14 is a schematic configuration diagram of a contactless power transmission system 10A (hereinafter also referred to as “system 10A”) according to the second embodiment of the present invention. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. The power feeding circuit 24a and the power receiving circuit 52a of the second embodiment are different from the power feeding circuit 24 and the power receiving circuit 52 of the first embodiment. Specific configurations of the power feeding circuit 24a and the power receiving circuit 52a will be described in detail with reference to FIG. Further, the power supply apparatus 12a of the system 10A does not have the power supply apparatus side camera 26.

[1-2. Electric circuit for wireless power feeding]
FIG. 15 is a diagram illustrating an electric circuit related to wireless power feeding from the power feeding device 12a to the vehicle 14a in the second embodiment.

(1-2-1. Power Feed Device 12a)
As shown in FIG. 15, the power supply circuit 24 a includes a power supply coil 80 a (hereinafter also referred to as “coil 80 a”) including a plurality of divided coils 120 and a plurality of capacitors 122. The coil 80a (divided coil 120) is a so-called solenoid coil (tubular coil) (see FIG. 16). In the power feeding circuit 24a, a plurality of LC circuits 124 in which one split coil 120 and one capacitor 122 are connected in parallel are arranged in parallel. Further, a switch 126 controlled by the control device 30 is disposed between each LC circuit 124 and the inverter 22.

FIG. 16 is an external perspective view showing a part of the power feeding circuit 24a of the power feeding device 12a and the power receiving circuit 52a of the vehicle 14a in the second embodiment. In FIG. 16, the front-rear direction (X direction), the left-right direction (Y direction), and the up-down direction (Z direction) are based on the vehicle 14a.

As shown in FIG. 16, the divided coils 120 constituting the power feeding coil 80 a are each spirally wound around a power transmission side core 130 (hereinafter also referred to as “core 130”). Each core 130 is a plate-like magnetic material. Each core 130 is linearly arranged at a predetermined interval in the direction of the central axis Ax1 of the power supply coil 80a (in other words, the direction orthogonal to the winding direction of the power supply coil 80a). Each core 130 is connected by resin 132 (FIG. 18). It should be noted that the resin 132 is omitted in FIG. Further, instead of providing a separate core 130 for each divided coil 120, a core 130 may be provided for each combination of a plurality of divided coils 120. For example, it is possible to wind four divided coils 120 around a single core 130.

(1-2-2. Vehicle 14a)
As illustrated in FIG. 15, the power receiving circuit 52 a includes a power receiving coil 100 a (hereinafter, also referred to as “coil 100 a”) including a plurality of divided coils 140, and a plurality of capacitors 142. The coil 100a (divided coil 140) is a so-called solenoid coil (tubular coil) (see FIG. 16). In the power receiving circuit 52a, a plurality of LC circuits 144 in which one split coil 140 and one capacitor 142 are connected in parallel are arranged in parallel. Further, a rectifier circuit 146 and a switch 148 are disposed between each LC circuit 144 and the battery 44 and the smoothing capacitor 90.

As shown in FIG. 16, the divided coils 140 constituting the power receiving coil 100a are spirally wound around each plate-shaped power receiving side core 150 (hereinafter also referred to as “core 150”). Each core 150 is linearly arranged at a predetermined interval in the direction of the central axis Ax2 of the power receiving coil 100a (in other words, the direction orthogonal to the winding direction of the power receiving coil 100a). Each core 150 is connected by resin 152 (FIG. 18). It should be noted that the resin 152 is omitted in FIG. Further, instead of providing a separate core 150 for each divided coil 140, a core 150 may be provided for each combination of a plurality of divided coils 140.

In the second embodiment, when the foreign object 300 enters between the power supply coil 80a and the power receiving coil 100a, only the split coils 120 and 140 that do not include the foreign object 300 are energized (for details, refer to FIGS. 17 and 18). Will be described later.)

2. Electric Power Supply Control FIG. 17 is a flowchart of control of the power supply control device 30 (power supply device 12a side) and ECU 58 (vehicle 14a side) during power transmission according to the second embodiment. FIG. 18 is a diagram for explaining operations of the power feeding coil 80a and the power receiving coil 100a during power transmission according to the second embodiment. The control device 30 is already in a standby state before starting the control of FIG. In FIG. 18, the split coils 120 and 140 that are energized are indicated by solid lines, and the split coils 120 and 140 that are not energized are indicated by broken lines.

17 are the same as steps S1 and S2 in FIG. However, in the second embodiment, since the power feeding device side camera 26 does not exist, the presence / absence of the foreign object 300 is determined using only the XY image Ixy from the vehicle side camera 54. In step S42, when the foreign object 300 exists (S42: YES), in step S43, the ECU 58 determines whether or not the total amount Φtz of the amount of magnetic flux in the Z direction is within the specified value THtz between the power feeding coil 80a and the power receiving coil 100a. Determine whether. This determination is the same as steps S21, S23, and S24 in FIG. In the second embodiment, only the total amount Φtz of the Z direction magnetic flux is determined. However, as in the first embodiment, the total amount Φtx of the X direction magnetic flux and the total amount Φty of the Y direction magnetic flux are determined. May be.

If there is no foreign object 300 in step S42 (S42: NO), or if the total magnetic flux amount Φtz is within the specified value THtz in step S43 (S43: YES), in step S44, the ECU 58 sets the normal mode as the power transmission mode. select. In the normal mode in the second embodiment, power is supplied using all the split coils 120 and 140.

On the other hand, when the total amount Φtz of the magnetic flux amount is not within the specified value THtz in step S43 (S43: NO), in step S45, the ECU 58 selects the output restriction mode as the power transmission mode. In the output restriction mode in the second embodiment, power is supplied using the divided

coils

120 and 140 with no foreign material 300 in between, and the divided

coils

120 and 140 with the foreign material 300 in between are not used for power supply. Therefore, transmission power is limited.

In step S46, the ECU 58 notifies the control device 30 of the divided coil 120 to be energized. That is, when the normal mode is selected, notification that all the divided coils 120 should be energized is given. When the output restriction mode is selected, it is notified that the divided coil 120 in which no foreign material 300 exists between the opposed divided coils 140 should be energized. For example, in the example of FIG. 18, the ECU 58 issues a command to the control device 30 to energize the left three divided coils 120.

Note that if the power supply device 12a can acquire information for determining the position of the foreign object 300 (for example, image data acquired by the camera 54) on the power supply device 12a side, the determination of the split coil 120 to be energized is performed. It can also be performed on the 12a side (for example, the control device 30).

During power feeding from the power feeding device 12a, the ECU 58 turns on a switch 148 (FIG. 15) corresponding to the split coil 140 corresponding to the split coil 120 that performs power feeding. On the other hand, the switch 148 corresponding to the split coil 140 corresponding to the split coil 120 to which power is not supplied is turned off. As a result, it is possible to avoid an eddy current in the split coil 120 that does not supply power from adversely affecting the power supply.

After step S46, in step S47, the ECU 58 determines whether or not to end the charging of the battery 44 with the electric power from the power supply device 12a. This determination is the same as step S7 in FIG.

If the charging of the battery 44 is not terminated (S47: NO), the process returns to step S42. Alternatively, step S47 may be simply repeated. When the charging of the battery 44 is to be ended (S47: YES), in step S48, the ECU 58 notifies the control device 30 that the charging should be ended.

When the ECU 58 notifies the control device 30 of the split coil 120 to be energized in step S46, the control device 30 supplies power to the vehicle 14a using the split coil 120 notified from the ECU 58 in step S51 of FIG. (Power transmission).

Specifically, the control device 30 turns on the switch 126 (FIG. 15) corresponding to the split coil 120 notified from the ECU 58. At this time, the switch 126 corresponding to the divided coil 120 not notified from the ECU 58 remains off. Then, the control device 30 controls the inverter 22 to convert the direct current from the direct current power supply 20 into an alternating current, and then supplies the alternating current to the power receiving coil 100a (the divided coil 140) via the power feeding coil 80a (the divided coil 140). Power). Thereby, the battery 44 is charged.

Next, in step S52, the control device 30 determines whether or not to end the power feeding. This determination is made based on whether or not a notification (S48) that power supply should be terminated has been received from the ECU 58 of the vehicle 14. When the power feeding is not finished (S52: NO), step S51 is repeated. When the power supply is terminated (S52: YES), the current power supply is terminated.

3. Effects of Second Embodiment As described above, according to the second embodiment, the side surfaces of the solenoid-type power feeding coil 80a (first power feeding coil) and the power receiving coil 100a (second power receiving coil) are opposed to each other. Then, power is supplied in a non-contact manner (see FIGS. 15, 16, and 18). The power feeding coil 80a and the power receiving coil 100a are configured by arranging a plurality of divided

coils

120 and 140, which are connected in parallel, in a straight line in the directions of the central axes Ax1 and Ax2 of the power feeding coil 80a and the power receiving coil 100a (FIG. 16). reference). Then, power transmission is stopped between the split coils 120 and 140 that sandwich the foreign object 300, and power is transmitted between the split coils 120 and 140 that do not sandwich the foreign object 300 (see FIGS. 17 and 18).

For this reason, the magnetic flux ring 160 (FIG. 18) formed by the split coils 120 and 140 that are energized does not interlink with the foreign material 300. Therefore, power supply can be performed while suppressing heat generation or power loss in the foreign material 300.

In the second embodiment, the power feeding coil 80a and the power receiving coil 100a are wound around

cores

130 and 150 made of a magnetic material (see FIGS. 16 and 18), and the non-energized coil is used as a magnetic path (FIG. 18). reference). As a result, it is possible to suppress leakage magnetic flux and improve power supply efficiency.

C. Modifications Note that the present invention is not limited to the above-described embodiments, and various configurations can be adopted based on the description of the present specification. For example, the following configuration can be adopted.

1. Applicable object In each of the above embodiments, the contactless

power transmission system

10, 10A is used for power feeding (charging) of the

vehicles

14, 14a, which are electric vehicles, but is used for other electric vehicles (hybrid vehicles, fuel cell vehicles, etc.). May be. Alternatively, the

systems

10 and 10A can be used not only for the

vehicles

14 and 14a but also for other moving bodies (such as ships and airplanes) that require power feeding. Alternatively, the

systems

10 and 10A may be applied to a manufacturing apparatus, a robot, or a home appliance that requires power supply.

2. Feeding coils 80 and 80a and receiving

coils

100 and 100a
[2-1. Coil type]
In the above embodiments, the power supply coils 80 and 80a and the power reception coils 100 and 100a are all solenoid type coils (see, for example, FIG. 16). However, for example, from the viewpoint of setting a limit value (upper limit value) of transmitted power per unit time according to the relative position of the foreign object 300, other types of coils can be used.

[2-2. Split coils 120, 140]
In the second embodiment, the divided coil 120 is obtained by equally dividing the power feeding coil 80a (see FIGS. 16 and 18). However, for example, from the viewpoint of selecting the split coil 120 to be energized according to the position of the foreign object 300, the size of each split coil 120 is not necessarily the same. The same applies to the split coil 140.

In the second embodiment, the number of the divided coils 120 and the number of the divided coils 140 is the same (see FIGS. 15 and 16). However, from the viewpoint of selecting the divided coils 120 to be energized according to the position of the foreign object 300, for example. The number of split coils 120 may be different from the number of split coils 140.

In the second embodiment, the split coils 120 and 140 (cores 130 and 150) are arranged in the front-rear direction of the vehicle 14a, respectively (see FIGS. 16 and 18). However, the split coils 120 and 140 (cores 130 and 150) can be arranged in other directions (for example, the left and right direction (vehicle width direction) of the vehicle 14a) in addition to or in place of the longitudinal direction of the vehicle 14a. It is.

[2-3. Core 130, 150]
In the second embodiment, the cores (cores 130 and 150) are used in both the feeding coil 80a and the power receiving coil 100a. However, for example, either one or both of the

cores

130 and 150 can be omitted.

3. Calculation of position of foreign object 300 [3-1. Position detecting means (imaging means)]
In the first embodiment, the power supply device-side camera 26 is used to detect the length Lz (height) of the foreign object 300 in the Z direction, and the vehicle-side camera 54 is used to detect the length of the foreign object 300 in the X and Y directions. Lx and Ly were detected. In the second embodiment, the lengths Lx and Ly are detected using the vehicle-side camera 54. However, from the viewpoint of determining the relative position of the foreign object 300 with respect to the power feeding coils 80 and 80a or the power receiving coils 100 and 100a, other configurations or methods may be used.

FIG. 19 is a diagram showing an arrangement of a pressure sensor 170 and a laser displacement meter 172 as a modified example of the position detection means of the foreign object 300. The pressure sensor 170 has a substantially rectangular shape in plan view, and is disposed on the feeding coil 80. By using the pressure sensor 170, the coordinates (Xn, Yn) of the foreign material 300 when viewed from the Z direction can be detected.

The laser displacement meter 172 is disposed in front of the parking space with respect to the feeding coil 80 of the feeding circuit 24, and detects the coordinates (Yn, Zn) of the foreign matter 300 in the feeding coil 80 and its surroundings when viewed from the X direction. be able to.

In each of the above embodiments and the modification of FIG. 19, the relative position of the foreign object 300 with respect to the feeding coil 80 is detected. However, from the viewpoint of setting a limit value (upper limit value) of transmitted power per unit time according to the relative position of the foreign object 300, it is also possible to detect the relative position with respect to the power receiving coil 100.

[3-2. Judgment subject]
In each of the above embodiments, the main body that determines the position of the foreign object 300 is the ECU 58 of the

vehicle

14 or 14a. However, if the configuration is such that information for determining the position of the foreign object 300 (for example, image data acquired by the camera 54) can be acquired on the

power supply device

12, 12a side, the

power supply device

12, 12a side (for example, the control device). It is also possible to determine the position of the foreign object 300 in 30).

4). Limitation of transmitted power In the first embodiment, the influence of the foreign object 300 is determined using the total amount of magnetic fluxes Φtx, Φty, and Φtz in the X direction, the Y direction, and the Z direction (see FIGS. 9 and 11), and the second embodiment. In the embodiment, the influence of the foreign matter 300 was determined using the total amount Φtz of the amount of magnetic flux in the Z direction (see FIG. 17). However, for example, from the viewpoint of determining the influence of the foreign object 300, other combinations (including the case where the total amount Φt of the magnetic flux amount in only one direction is used) may be used. In the first embodiment, the total sums Φtx, Φty, and Φtz of the magnetic flux amounts in the X direction, the Y direction, and the Z direction are individually used. However, they can be combined and used.

In each of the embodiments described above, the necessity of limiting transmission power was determined using the total amount of magnetic flux Φt (see FIG. 11 and the like). However, it is also possible to determine whether or not it is necessary to limit the power supply by other methods. For example, the determination may be performed directly from position information of the foreign object 300 (for example, coordinates on the XY plane). For example, in the state where the XY plane (or its coordinates) is set as shown in FIG. 12, the coordinates for limiting the transmission power are set in advance. And when the foreign material 300 exists in the said coordinate, it is also possible to restrict | limit transmission power.

In each of the above embodiments, the normal mode and the output restriction mode are used as the power transmission mode (see FIGS. 9 and 17). However, for example, from the viewpoint of providing a limit value of transmitted power per unit time according to the relative position of the foreign object 300, the present invention is not limited to this. For example, in addition to the normal mode, it is also possible to provide a plurality of output restriction modes having different transmission power limit values per unit time. Alternatively, in addition to the normal mode and the output restriction mode, a power transmission stop mode for stopping power transmission can be used.

5. Others In the second embodiment, the ECU 58 of the vehicle 14a determines the split coil 120 to be energized. However, if the configuration is such that the position of the foreign object 300 or information for determining this (for example, image data acquired by the camera 54) can be acquired on the power supply device 12a side, the power supply device 12a side (for example, the control device 30). It is also possible to make this determination in step (b).

In each of the above embodiments, power is supplied from the

power supply devices

12 and 12a to the

vehicles

14 and 14a. However, the present invention can also be applied to a case where power is supplied from the

vehicles

14 and 14a to the

power supply devices

12 and 12a.

In the first embodiment, in addition to the switch 86 of the power feeding circuit 24, the switch 108 of the power receiving circuit 52 is provided (FIG. 3). In the second embodiment, in addition to the switch 126 of the power feeding circuit 24a, the switch 148 of the power receiving circuit 52a is provided (FIG. 15). However, if attention is paid to the limitation of the transmission power based on the foreign object 300, a configuration in which the

switches

108 and 148 are not provided is also possible.

Claims

A non-contact power transmission system (10, 10A) that performs non-contact power transmission from the power feeding unit (80, 80a) to the power receiving unit (100, 100a),
Detecting the relative position of the foreign object (300) with respect to the power feeding unit (80, 80a) or the power receiving unit (100, 100a);
Limiting the transmission power per unit time from the power supply unit (80, 80a) to the power reception unit (100, 100a) according to the total amount of magnetic flux in the foreign object (300) estimated based on the relative position A non-contact power transmission system (10, 10A) characterized by setting a value.
In the non-contact power transmission system (10, 10A) according to claim 1,
Power is transmitted in a contactless manner with the side surfaces of the solenoid-type first coil for power supply (80, 80a) and the second coil for power reception (100, 100a) facing each other,
A set of plane coordinates in a direction in which one of the first coil (80, 80a) or the second coil (100, 100a) is viewed from the other is used as a relative position of the foreign object (300). Contact power transmission system (10, 10A).
In the non-contact power transmission system (10, 10A) according to claim 2,
An imaging means (54) for imaging the foreign object (300);
The non-contact power transmission system (10, 10A), wherein the set of the plane coordinates as the relative position of the foreign object (300) is detected based on an image acquired by the imaging means (54).
In the non-contact power transmission system (10A) according to claim 1,
Power is transmitted in a contactless manner with the side surfaces of the solenoid-type first coil for power supply (80a) and the second coil for power reception (100a) facing each other,
The first coil (80a) and the second coil (100a) include a plurality of divided coils (120, 140) connected in parallel, the first coil (80a) and the second coil (100a). Are arranged in a straight line in the direction of the central axis of
Power transmission is stopped between the split coils (120, 140) sandwiching the foreign object (300), and power is transmitted between the split coils (120, 140) not sandwiching the foreign object (300). Characteristic contactless power transmission system (10A).
In the non-contact power transmission system (10A) according to claim 4,
At least one of the first coil (80a) and the second coil (100a) is wound around a core (130, 150) made of a magnetic material, and the non-energized coil is used as a magnetic path. A contactless power transmission system (10A).
A non-contact power transmission system (10, 10A) that performs non-contact power transmission from the power feeding unit (80, 80a) to the power receiving unit (100, 100a),
Detecting the relative position of the foreign object (300) with respect to the power feeding unit (80, 80a) or the power receiving unit (100, 100a);
A contactless power transmission system (10, 10A), wherein a limit value of transmitted power per unit time from the power feeding unit (80, 80a) to the power receiving unit (100, 100a) is changed according to the relative position. ).