Contactless power supply device and contactless power supply system

Abstract

A contactless power supply device (100) includes: a plurality of primary coils (112) disposed on a road; and a power transmission control unit (150) that uses a portion of the primary coils (112) as a power transmission implementation coil (PSC) and transmits power from the power transmission implementation coil (PSC) to a secondary coil (212) installed in a vehicle (200). The power transmission control unit (150) uses a specific primary coil (CC) different from the power transmission implementation coil (PSC) among the plurality of primary coils (112) to reduce leakage magnetic flux generated by energizing the power transmission implementation coil (PSC). Instead of using the specific primary coil (CC), the secondary coil (212) may be used to limit the leakage magnetic flux.

Description

[0001] Citation of related applications

[0002] This application claims priority based on Japanese Patent Application No. 2018-135060 filed on July 18, 2018 and Japanese Patent Application No. 2019-038160 filed on March 4, 2019, all disclosed contents of which are incorporated into this application by reference. Technical Field

[0003] The present disclosure relates to a technology for supplying power to a vehicle in a contactless manner during driving of the vehicle. Background Art

[0004] JP2014-110726A discloses a technology for supplying power to a vehicle in a contactless manner. In this prior art, when power is supplied during vehicle stop, a cancellation coil is used to reduce leakage magnetic flux. The cancellation coils are respectively arranged on the back side of the power transmission coil and the back side of the power reception coil. Summary of the invention

[0005] In the above-mentioned prior art, it is necessary to set a cancellation coil separately from the power transmission coil and the power receiving coil, so there is a problem that the device is large-scale and the cost is also increased. In addition, the above-mentioned prior art relates to a power supply technology during parking, and there is a problem that it cannot be applied to a technology for powering the vehicle while the vehicle is running. Therefore, it is desired to have a technology that can reduce the leakage flux when the vehicle is powered in a non-contact manner while the vehicle is running.

[0006] According to one embodiment of the present disclosure, there is provided a contactless power supply device for supplying power to a vehicle in a contactless manner during the driving of the vehicle. The contactless power supply device includes: a plurality of primary coils, the plurality of primary coils being arranged on a road; and a power transmission control unit, the power transmission control unit using a portion of the primary coils of the plurality of primary coils as power transmission implementation coils, and performing power transmission from the power transmission implementation coils to a secondary coil installed on the vehicle, the power transmission control unit using a specific primary coil of the plurality of primary coils that is different from the power transmission implementation coil to reduce leakage magnetic flux generated by energizing the power transmission implementation coil.

[0007] According to this contactless power supply device, it is possible to reduce leakage magnetic flux without separately providing a cancel coil in addition to the plurality of primary coils.

[0008] According to another embodiment of the present disclosure, there is provided a contactless power supply system, which uses a plurality of primary coils arranged on a road and a secondary coil installed on a vehicle to supply power to the vehicle in a contactless manner during the travel of the vehicle. The contactless power supply system includes: a power transmission control unit, which uses a portion of the primary coils of the plurality of primary coils as a power transmission implementation coil and performs power transmission from the power transmission implementation coil; and a control device, which controls the operation of the secondary coil, wherein the contactless power supply system performs at least one of the following processes: (a) a first process, in which the power transmission control unit uses a specific primary coil of the plurality of primary coils that is different from the power transmission implementation coil to reduce the leakage magnetic flux generated by the energization of the power transmission implementation coil; and (b) a second process, in which the control device reduces the leakage magnetic flux generated by the energization of the power transmission implementation coil by passing a current through the secondary coil without receiving power based on the secondary coil.

[0009] According to this contactless power supply system, it is possible to reduce leakage magnetic flux without separately providing a cancel coil in addition to the plurality of primary coils. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 : is a block diagram showing the overall configuration of a contactless power supply system during driving.

[0011] Figure 2 It is an explanatory diagram showing a power supply section set in a driving lane.

[0012] Figure 3 It is an explanatory diagram showing an example of the coil structure of the primary coil and the secondary coil.

[0013] Figure 4 It is an explanatory diagram showing the power transmission implementation coil and the cancellation coil in the first embodiment.

[0014] Figure 5 This is an explanatory diagram showing a state in which leakage magnetic flux is reduced by the canceling coil.

[0015] Fig. 6A It is an explanatory diagram showing an example of the circuit configuration of the power transmission circuit and the power transmission coil unit.

[0016] Figure 6B It is an explanatory diagram showing another example of the circuit configuration of the power transmission circuit and the power transmission coil unit.

[0017] Figure 7 This is a graph showing an example of the relationship between the gap G between the primary coil and the secondary coil and the distance L between the power transmission coil and the cancellation coil.

[0018] Figure 8 It is an explanatory diagram showing a power transmission implementation coil and a cancellation coil in the second embodiment.

[0019] Fig. 9 It is an explanatory diagram showing an example of the circuit configuration of the power transmission circuit and the power transmission coil unit in the second embodiment.

[0020] Fig.10 1 is an explanatory diagram showing an example of a control target coil in the second embodiment.

[0021] Fig.11 It is an explanatory diagram showing a power transmission implementation coil and a cancellation coil in the third embodiment.

[0022] Fig.12 It is an explanatory diagram showing an example of two vehicles traveling in a power supply section in the third embodiment.

[0023] Fig.13 It is an explanatory diagram showing a power transmission implementation coil and a cancellation coil in the fourth embodiment.

[0024] Fig.14 It is an explanatory diagram of an example of a vehicle traveling in a power supply section in another embodiment.

[0025] Fig.15 This is an explanatory diagram showing an example of a vehicle traveling in a power supply section in still another embodiment.

[0026] Fig.16A This is an explanatory diagram showing a structure in which a cut portion is provided on a magnetic yoke of a primary coil.

[0027] Fig. 16B It is an explanatory diagram showing the magnetic resistance of a magnetic yoke having a cut-off portion.

[0028] Fig. 16C This is a graph showing the relationship between the cut width of the magnetic yoke and the composite relative permeability.

[0029] Fig.16D It is a graph showing the relationship between the composite relative permeability of the magnetic yoke, the coupling coefficient, and the leakage electromagnetic field.

[0030] Fig.17A This is an explanatory diagram of leakage magnetic flux when a magnetic yoke without a cutout portion is used.

[0031] Fig. 17B It is an explanatory diagram of leakage magnetic flux when a magnetic yoke having a cut-off portion is used.

[0032] Fig.18 This is an explanatory diagram showing another structure in which a cut portion is provided on the magnetic yoke of the primary coil.

[0033] Fig.19 This is an explanatory diagram showing a usage state of the cancel coil in the case of adopting a circuit configuration in which the DD coil of the primary coil is energized by one power transmission circuit.

[0034] Fig. 20 This is an explanatory diagram showing a usage state of the cancel coil in the case of adopting a circuit configuration in which the DD coil of the primary coil is energized through two power transmission circuits.

[0035] Fig.21 It means omitted Fig. 20 An explanatory diagram of an example of a situation where one coil of the DD coil is used.

[0036] Fig.22A This is an explanatory diagram showing the use state of the power transmission implementation coil and the cancellation coil in the case of adopting a circuit configuration in which the DD coil of the primary coil is energized by two power transmission circuits.

[0037] Fig. 22B Yes means Fig.22A A graph showing the relationship between the current phase of the cancellation coil in the structure and the leakage electromagnetic field along the direction of vehicle travel.

[0038] Fig. 22C Yes means Fig.22A A graph of the current phase of the cancellation coil in the structure and the leakage electromagnetic field along the vehicle width direction.

[0039] Fig.23A It means omitted Fig.22A An explanatory diagram of the situation of one coil of the DD coil.

[0040] Fig. 23B Yes means Fig.23A A graph showing the current phase of the cancellation coil in the structure and the leakage electromagnetic field along the vehicle's traveling direction.

[0041] Fig.23C Yes means Fig.23A A graph of the current phase of the cancellation coil in the structure and the leakage electromagnetic field along the vehicle width direction. DETAILED DESCRIPTION

[0042] A. First Implementation Method:

[0043] like Figure 1 As shown, the contactless power supply system during driving includes a contactless power supply device 100 provided on a road RS and a vehicle 200 traveling on the road RS, and can supply power from the contactless power supply device 100 to the vehicle 200 in a contactless manner during the driving of the vehicle 200. The vehicle 200 is configured as an electric vehicle or a hybrid vehicle, for example. Figure 1In the figure, the x-axis direction indicates the traveling direction of the vehicle 200, the y-axis direction indicates the width direction of the vehicle 200, and the z-axis direction indicates the vertical upward direction. The directions of the x, y, and z axes in other figures described later also indicate the same Figure 1 Same direction.

[0044] The contactless power supply device 100 includes a plurality of power transmission coil units 110, a plurality of power transmission circuits 120 for supplying AC voltage to the plurality of power transmission coil units 110, a power supply circuit 130 for supplying DC voltage to the plurality of power transmission circuits 120, a power receiving coil position detection unit 140, and a power transmission control unit 150 for controlling power transmission.

[0045] A plurality of power transmission coil units 110 are arranged along the traveling direction of the road RS. Each power transmission coil unit 110 includes a primary coil. The primary coil is also referred to as a "power transmission coil". A specific structural example of the power transmission coil unit 110 will be described later. The primary coil does not need to be configured as the power transmission coil unit 110, as long as a plurality of primary coils are arranged along the traveling direction of the road RS.

[0046] The plurality of power transmission circuits 120 are inverter circuits that convert the DC voltage supplied from the power supply circuit 130 into a high-frequency AC voltage and apply it to the primary coil of the power transmission coil unit 110. The power supply circuit 130 is a circuit that supplies a DC voltage to the power transmission circuit 120. For example, the power supply circuit 130 is configured as an AC / DC converter circuit that rectifies the AC voltage of an external power supply to output a DC voltage. The DC voltage output by the power supply circuit 130 may not be a complete DC voltage, but may include a certain degree of variation (fluctuation).

[0047] The receiving coil position detection unit 140 detects the position of the receiving coil unit 210 installed in the vehicle 200 in the x direction. The receiving coil position detection unit 140 may detect the position of the receiving coil unit 210 based on the magnitude of the transmission power and the transmission current in the plurality of transmission circuits 120, or may detect the position of the receiving coil unit 210 using wireless communication with the vehicle 200 or a sensor that detects the position of the vehicle 200. The plurality of transmission circuits 120 perform power transmission using one or more transmission coil units 110 close to the receiving coil unit 210 based on the position of the receiving coil unit 210 detected by the receiving coil position detection unit 140. The primary coil included in the transmission coil unit 110 that performs power transmission is also referred to as a "power transmission implementation coil."

[0048] Vehicle 200 includes a power receiving coil unit 210 , a power receiving circuit 220 , a main battery 230 , a motor generator 240 , an inverter circuit 250 , a DC / DC converter circuit 260 , an auxiliary equipment battery 270 , auxiliary equipment 280 , a control device 290 , and a communication device 295 .

[0049] The power receiving coil unit 210 includes a secondary coil, and is a device that generates an induced electromotive force through electromagnetic induction with the primary coil of the power transmitting coil unit 110. The secondary coil is also called a "power receiving coil". The power receiving circuit 220 is a circuit that converts the AC voltage output from the power receiving coil unit 210 into a DC voltage suitable for charging the main battery 230. For example, the power receiving circuit 220 is configured as a circuit including a rectifier circuit that converts the AC voltage into a DC voltage and a DC / DC converter circuit that boosts the DC voltage. The DC voltage output from the power receiving circuit 220 can be used for charging the main battery 230, and can also be used for charging the auxiliary device battery 270, driving the electric generator 240, and driving the auxiliary device 280.

[0050] The main battery 230 is a secondary battery that outputs a relatively high DC voltage for driving the motor generator 240. The motor generator 240 operates as a three-phase AC motor and generates a driving force for the vehicle 200 to travel. When the vehicle 200 decelerates, the motor generator 240 operates as a generator and generates a three-phase AC voltage. When the motor generator 240 operates as a motor, the inverter circuit 250 converts the DC voltage of the main battery 230 into a three-phase AC voltage and supplies it to the motor generator 240. When the motor generator 240 operates as a generator, the inverter circuit 250 converts the three-phase AC voltage output by the motor generator 240 into a DC voltage and supplies it to the main battery 230.

[0051] The DC / DC converter circuit 260 converts the DC voltage of the main battery 230 into a lower DC voltage and supplies it to the auxiliary equipment battery 270 and the auxiliary equipment 280. The auxiliary equipment battery 270 is a secondary battery that outputs a relatively low DC voltage for driving the auxiliary equipment 280. The auxiliary equipment 280 is a peripheral device such as an air conditioner and an electric power steering device.

[0052] The control device 290 controls each part in the vehicle 200. When receiving contactless power supply during driving, the control device 290 controls the power receiving circuit 220 and performs power reception. The communication device 295 is a wireless communication device that performs vehicle-to-vehicle communication, road-to-vehicle communication, etc. For example, the communication device 295 can communicate with the power receiving coil position detection unit 140 as road-to-vehicle communication.

[0053] The receiving coil position detection unit 140 of the contactless power supply device 100 preferably also detects the gap G between the primary coil of the power transmission coil unit 110 and the secondary coil of the power reception coil unit 210 as the position of the power reception coil unit 210. For example, the receiving coil position detection unit 140 can obtain the height information from the road surface to the secondary coil of the power reception coil unit 210 through wireless communication with the vehicle 200, and use the height information to determine the gap G between the primary coil of the power transmission coil unit 110 and the secondary coil of the power reception coil unit 210. The gap G between the primary coil and the secondary coil refers to the distance between the primary coil and the secondary coil in the vertical direction (z direction).

[0054] like Figure 2 As shown in FIG. 1 , it is assumed that on a road having two driving lanes RL11 and RL12 and two opposing lanes RL21 and RL22, a power supply section PSA is set in the driving lane RL11 where the vehicle 200 is traveling. Figure 1 The contactless power supply device 100 described in . A sidewalk SW1 is provided outside the driving lanes RL11 and RL2, and a sidewalk SW2 is also provided outside the opposing lanes RL21 and RL22. A pedestrian HM is present on the sidewalk SW1. The two-wheeled vehicle BK is traveling on the driving lane RL12 adjacent to the vehicle 200.

[0055] exist Figure 2 In the example shown, a non-contact sensor 142 using infrared rays or the like is provided at the entrance of the power supply section PSA, and the vehicle 200 entering the power supply section PSA is detected using the non-contact sensor 142. The power receiving coil position detection unit 140 can detect the position of the vehicle 200 and the position of the power receiving coil unit 210 thereof using the detection result from the non-contact sensor 142 and the vehicle speed of the vehicle 200 acquired through the road-to-vehicle communication.

[0056] like Figure 3 As shown, the power transmission coil unit 110 has a primary coil 112 and a magnetic yoke 114. The power reception coil unit 210 has a secondary coil 212 and a magnetic yoke 214. The primary coil 112 is configured as a single-phase coil. The secondary coil 212 is configured as a two-phase coil including an A-phase coil 212a and a B-phase coil 212b. Each coil 112, 212a, 212b is configured as a concentrated winding coil having two or more windings, but Figure 3 The black dots "·" and crosses "×" marked in the circles representing the coil wires of each coil indicate that the current direction is in the opposite direction. The primary coil 112 can also be configured as a multi-phase coil with more than two phases. In addition, the secondary coil 212 can be configured as a single-phase coil, or it can be configured as a three-phase coil.

[0057] The magnetic yokes 114 and 214 are so-called back yokes, and are used to increase the magnetic flux density around the coils 112 and 212. The magnetic yoke 114 of the power transmission coil unit 110 is arranged on the back side of the primary coil 112. The "back side of the primary coil 112" refers to the side opposite to the gap between the primary coil 112 and the secondary coil 212. Similarly, the magnetic yoke 214 of the power receiving coil unit 210 is arranged on the back side of the secondary coil 212. A magnetic core may be provided in the primary coil 112 and the secondary coil 212 separately from the magnetic yokes 114 and 214. In addition, a magnetic shielding plate made of non-magnetic metal may be provided on the back side of the magnetic yokes 114 and 214, respectively.

[0058] The frequency of the AC voltage applied to the primary coil 112 is set to a high enough frequency so that the secondary coil 212 is considered to be almost stopped during the running of the vehicle 200 during the power transmission from the primary coil 112 to the secondary coil 212. Figure 3 In the above example, if it is assumed that the secondary coil 212 moves at a constant speed in the x direction, the moving frequency f of the secondary coil 212 can be calculated by the following equation: 212 Perform calculations.

[0059] [Mathematical formula 1]

[0060]

[0061] Here, p 112 is the spacing of the primary coil 112 [m], v 212 is the moving speed of the secondary coil 212 [m / s]. 212 It can be considered as the frequency when the secondary coil 212 moves along the arrangement direction of the plurality of primary coils 112. For example, when the moving frequency f of the secondary coil 212 in the contactless power supply during driving is 212 When the frequency of the AC voltage applied to the primary coil 112 is within the range of tens of Hz to hundreds of Hz, the frequency of the AC voltage applied to the primary coil 112 is set to a value within the range of tens of kHz to hundreds of kHz. 212 If the value is sufficiently large, it can be considered that the power transmission from the primary coil 112 to the secondary coil 212 is almost stopped even when the vehicle 200 is running.

[0062] like Figure 4As shown, in the first embodiment, the primary coil 112 of the power transmission coil unit 110 located directly below the power receiving coil unit 210 functions as a power transmission implementation coil PSC for transmitting power to the power receiving coil unit 210. The primary coils of the two power transmission coil units separated by a distance L from the power transmission implementation coil PSC in the x direction are selected as cancellation coils CC. The cancellation coil CC is used to reduce the leakage magnetic flux generated by the energization of the power transmission implementation coil PSC. The distance L between the two primary coils 112 refers to the distance between the centers of the two primary coils 112. The setting of the distance L will be described later.

[0063] like Figure 5 As shown, in the first embodiment, the leakage magnetic flux is reduced by short-circuiting both ends of the cancellation coil CC. Figure 5 The main magnetic flux MF and leakage magnetic flux LF0 generated when only the power transmission implementation coil PSC is energized without energizing the other primary coils 112 are depicted. If the cancellation coil CC is short-circuited, an electromotive force is generated in the cancellation coil CC due to the leakage magnetic flux LF0, and a current that generates a magnetic flux in the opposite direction to the leakage magnetic flux LF0 flows through the cancellation coil CC. As a result, the leakage magnetic flux LF0 near the cancellation coil CC is reduced to become the reduced leakage magnetic flux LF1. As a result, malfunction of electronic equipment or communication equipment and exposure of the human body can be prevented. The short circuit of the cancellation coil CC can be performed using the circuit structure described below.

[0064] like Fig. 6A As shown, the power transmission circuit 120 is connected to the power supply circuit 130 and receives a DC voltage from the power supply circuit 130. The power transmission circuit 120 includes an inverter circuit composed of a full-bridge circuit 20 having four switches 21 to 24 and a capacitor 26. The capacitor 26 can be omitted. In this example, each of the four switches 21 to 24 is a transistor element having a return diode FWD connected in parallel. Switching signals of the four switches 21 to 24 are supplied from the power transmission control unit 150. A primary coil 112 is connected to the two output terminals of the full-bridge circuit 20 via a bandpass filter 122. A resonant capacitor 116 is connected in parallel to the primary coil 112. However, the resonant capacitor 116 may also be connected in series with the primary coil 112. The bandpass filter 122 may be omitted, or other filter circuits such as a high-pass filter or a low-pass filter may be used instead of the bandpass filter 122. In Fig. 6A In the circuit structure, when the primary coil 112 is used as the cancelling coil CC, the two ends of the primary coil 112 as the cancelling coil CC can be short-circuited by turning on both the two upper arm switches 21 and 23 or turning on both the two lower arm switches 22 and 24. Fig. 6A In the embodiment, since the resonance capacitor 116 is connected in parallel with the primary coil 112 to form a resonance circuit, the entire resonance circuit is short-circuited.

[0065] like Figure 6B As shown, switches 31 and 32 for short-circuiting can be provided in the power transmission coil section 110. In this example, each of the switches 31 and 32 is a transistor element connected in parallel with a return diode FWD. In addition, the two switches 31 and 32 are connected in opposite directions to each other, and the series connection of the two switches 31 and 32 is connected in parallel with the primary coil 112. Switching signals of the switches 31 and 32 are supplied from the power transmission control section 150. By turning on the two switches 31 and 32 at the same time, both ends of the primary coil 112, which serves as a cancellation coil CC, can be short-circuited. Figure 6B In the embodiment, the resonant capacitor 116 is connected in series with the primary coil 112, but the resonant capacitor 116 may be connected in parallel with the primary coil 112. Figure 6B In the embodiment, since the resonant capacitor 116 is connected in series with the primary coil 112, the resonant circuit is not short-circuited by the switches 31 and 32, but only the primary coil 112 is short-circuited. Fig. 6A The structure is different. Figure 6B In the circuit, the filter circuit may be provided in the front stage of the power transmission coil unit 110. In this case, the switches 31 and 32 may be provided between the filter circuit and the full bridge circuit 20, thereby obtaining a circuit configuration having the same effect as short-circuiting the coil 112.

[0066] Figure 4 The phase relationship between the currents I1, I2, Ia, and Ib in the complex plane having the real axis Re and the imaginary axis Im is shown. The use of these currents I1, I2, Ia, and Ib complements the effect of reducing the leakage flux obtained by short-circuiting the cancellation coil CC. If the current I1 flows to the primary coil side, since power transmission occurs, the current I2 is offset by 90 degrees and flows to the secondary side due to the influence of the capacitor. Here, the respective actions in the case where the capacitor is not included and only the cancellation coil CC is short-circuited, and in the case where the capacitor is included and the cancellation coil CC is short-circuited are as follows. First, if the capacitor is not included and the cancellation coil CC is short-circuited, a current Ia with the same phase as the current I1 on the primary side is generated in the cancellation coil CC. The reason is that the induced current flows in order to suppress the change of the magnetic flux interlinked with the cancellation coil CC. The current Ia flows through the cancellation coil CC in such a way that the magnetic flux does not change, thereby reducing the leakage flux. On the other hand, when the capacitor is included and the cancellation coil CC is short-circuited, the current Ib flows in a phase opposite to the current I2 on the secondary side. The reason is that the capacitor is included, so the phase is shifted by 90 degrees compared to the case where only the cancellation coil CC is short-circuited. As a result, the current Ib flows with a phase reversed by 180 degrees with respect to the current I2 on the secondary side, so the leakage flux can be reduced.

[0067] like Figure 7 As shown, preferably, the distance L between the power transmission implementation coil PSC and the cancellation coil CC is set to be the gap G between the power transmission implementation coil PSC and the secondary coil 212 (refer to Figure 4 The reason is that if the primary coil 112 close to the power transmission implementation coil PSC is used as a cancellation coil when the gap G is small, the cancellation coil CC may reduce the main magnetic flux MF, thereby reducing the efficiency. Figure 7 The relationship can also be applied to other embodiments described later. In addition, the distance L can be set to a constant value regardless of the gap G. In this case, the distance L is determined in advance through experiments or experience.

[0068] In addition, if Figure 2 As shown, when there is a pedestrian HM or a two-wheeled vehicle BK near the vehicle 200 receiving power, it is preferred that the primary coil 112 arranged in the y direction relative to the pedestrian HM or the two-wheeled vehicle BK is not used as a cancelling coil CC. The reason is that if the primary coil 112 located next to the pedestrian HM and the two-wheeled vehicle BK is used as a cancelling coil CC, the magnetic field around it changes, which may have an adverse effect on the pedestrian HM and the driver of the two-wheeled vehicle BK. The position of the pedestrian HM and the two-wheeled vehicle BK can be detected by, for example, obtaining the detection results of the peripheral sensors (camera, radar, etc.) installed in the vehicle 200 through the non-contact power supply device 100 using the road-to-vehicle communication.

[0069] As described above, in the first embodiment, the power transmission control unit 150 uses a specific primary coil 112, namely, a cancellation coil CC, which is different from the power transmission implementation coil PSC among the multiple primary coils 112 to reduce the leakage magnetic flux generated by energizing the power transmission implementation coil PSC. Therefore, the leakage magnetic flux can be reduced without providing other cancellation coils in addition to the multiple primary coils 112. In particular, in the first embodiment, since the leakage magnetic flux is reduced by short-circuiting the two ends of the cancellation coil CC, the leakage magnetic flux can be reduced without causing useless current to flow through the cancellation coil CC.

[0070] B. Second Implementation Method:

[0071] like Figure 8 As shown, according to the second embodiment, the contactless power supply device 100 includes a leakage flux detection unit 160 that detects leakage flux in each power transmission coil unit 110. The primary coil 112 of the power transmission coil unit 110 having a larger leakage flux detected by the leakage flux detection unit 160 is used as a cancellation coil CC. In the second embodiment, the leakage flux is reduced by allowing a cancellation current Icc to flow through the cancellation coil CC using the power transmission circuit 120. The phase of the cancellation current Icc flowing in the cancellation coil CC is set to be able to reduce the leakage flux. Figure 8In the example of FIG. 1 , the phase of the cancellation current Icc is shifted by 180 degrees from the phase of the power transmission current Isc flowing through the power transmission implementation coil PSC.

[0072] like Fig. 9 As shown, the canceling current Icc flowing in the canceling coil CC is adjusted according to the leakage magnetic flux detected by the leakage magnetic flux detection unit 160. A voltage sensor 40 for measuring the voltage of the primary coil 112 and a current sensor 50 for measuring the output current of the inverter circuit are provided in the power transmission circuit 120. A voltage corresponding to the leakage magnetic flux is generated in the primary coil 112. The leakage magnetic flux detection unit 160 detects the leakage magnetic flux at the position of the primary coil 112 based on the voltage measured by the voltage sensor 40. The power transmission control unit 150 applies a voltage to the canceling coil CC by using the power transmission circuit 120 to generate a canceling current Icc that reduces the leakage magnetic flux. Generally, it is preferable to set the canceling current Icc to be smaller than the power transmission current Isc. In this way, by allowing a relatively small current to flow through the canceling coil CC, the leakage magnetic flux can be reduced.

[0073] If the leakage flux is detected using the leakage flux detection unit 160, the direction and current amount of the cancellation current Icc of the cancellation coil CC can be adjusted to an appropriate direction and current amount for reducing the leakage flux. In adjusting the cancellation current Icc, any control method such as feedback control and feedforward control can be used. As a target (control target coil) for reducing the leakage flux by current control of the cancellation coil CC, the cancellation coil CC itself can be used, or a primary coil 112 different from the cancellation coil CC can be used.

[0074] exist Fig.10 In the example shown, the primary coil 112 located at a specific position (specifically, at the end of the power supply section PSA) in the power supply section PSA is used as the control target coil TC. In addition, the primary coil 112 other than the control target coil TC and the cancellation coil CC is omitted. Fig.10 In the case of, by controlling the current of the cancellation coil CC, the leakage magnetic flux in the control target coil TC can be reduced. Such a control target coil TC can be preset in consideration of the surrounding environment. When such a control target coil TC is used, as the control amount in the current control of the cancellation coil CC, for example, the leakage magnetic flux in the control target coil TC can be used. As an index value representing the leakage magnetic flux, the induced voltage of the control target coil TC can be used. Fig. 9 As also described in , the induced voltage of the control target coil TC caused by the leakage magnetic flux can be measured by the voltage sensor 40. In addition, the target value of the induced voltage may be 0V, or may be an allowable voltage value close to 0V.

[0075] As described above, in the second embodiment, the power transmission control unit 150 controls the circuit elements connected to the cancellation coil CC so that the current in the direction of reducing the leakage magnetic flux flows through the cancellation coil CC, so that the leakage magnetic flux can be reduced by passing the current through the cancellation coil CC. In the second embodiment, the selection of the cancellation coil CC, the adjustment of the current amount and phase of the cancellation current are performed based on the leakage magnetic flux detected by the leakage magnetic flux detection unit 160, but the leakage magnetic flux detection unit 160 can also be omitted. In this case, for example, the primary coil 112 located at a predetermined distance L from the power transmission implementation coil PSC can also be selected as the cancellation coil CC, and the current amount and phase of the cancellation current Icc can be set to predetermined values.

[0076] C. Third Implementation Method:

[0077] like Fig.11 As shown, in the third embodiment, it is assumed that two vehicles 200a and 200b are traveling in the same driving lane. In this case, the first power transmission current Isc1 flows through the power transmission implementation coil PSCa that transmits power to the first vehicle 200a, and the second power transmission current Isc2 flows through the power transmission implementation coil PSCb that transmits power to the second vehicle 200b. In the third embodiment, the phase of the second power transmission current Isc2 is adjusted in a manner to reduce the leakage magnetic flux generated by the first power transmission current Isc1. Fig.11 In the example of FIG. 1 , the phase of the second power transmission current Isc2 is an opposite phase shifted by 180 degrees from the phase of the first power transmission current Isc1 .

[0078] However, there are also cases where it is preferable to set the two power transmission currents Isc1 and Isc2 to the same phase in terms of reducing the leakage magnetic flux. For example, as a plurality of primary coils 112 arranged along the x direction, it is assumed that the primary coils 112 wound in opposite directions to each other are arranged alternately along the x direction. At this time, depending on the distance VL between the two vehicles 200a and 200b, the winding methods of the coils of the two power transmission implementation coils PSCa and PSCb are sometimes opposite. In such a case, it is preferable to set the power transmission currents Isc1 and Isc2 of the two power transmission implementation coils PSCa and PSCb to the same phase in terms of reducing the leakage magnetic flux. The positional relationship between the power receiving coil units 210 of the two vehicles 200a and 200b can be detected based on the detection result of the power receiving coil unit 210 by the power receiving coil position detection unit 140.

[0079] When two vehicles 200a and 200b are traveling in the same power supply area PSA, Fig.11As described above, in many cases, it is preferable to set the inverter currents Isc1 and Isc2 to opposite phases. However, if the phase of the inverter current Isc2 is immediately reversed from the phase of the inverter current Isc1 used for the first vehicle 200a when the second vehicle 200b enters the power supply interval PSA, a large power pulsation may occur. Therefore, the phase difference between the inverter currents Isc1 and Isc2 may be gradually changed while using the position information of the two vehicles 200a and 200b. Alternatively, the phase of the inverter current may be reversed after one vehicle (for example, the rear vehicle 200b) is temporarily stopped.

[0080] As described above, in the third embodiment, in order to reduce the leakage magnetic flux generated by power transmission to the first vehicle 200a, the power transmission control unit 150 can reduce the leakage magnetic flux using the primary coil 112 that performs power transmission to another vehicle 200a different from the first vehicle 200a.

[0081] D. Fourth Implementation Method:

[0082] like Fig.12 As shown, the fourth embodiment is the same as the third embodiment in that it is assumed that the two vehicles 200a and 200b are traveling in the same driving lane. In the fourth embodiment, the primary coil 112 different from the power transmission coils PSCa and PSCb that transmit power to the two vehicles 200a and 200b is used as a cancellation coil CC to reduce leakage magnetic flux.

[0083] In particular, it is preferable to perform the reduction of the leakage flux according to the fourth embodiment when the distance VL between the power receiving coil units 210 of the two vehicles 200a and 200b (i.e., the distance between the secondary coils) is greater than a predetermined threshold. For example, it is also possible to reduce the leakage flux according to the third embodiment when the distance VL is less than the threshold, and to reduce the leakage flux according to the fourth embodiment when the distance VL is greater than the threshold. However, when the two vehicles 200a and 200b are traveling in the front and rear direction, the leakage flux can be reduced according to the fourth embodiment regardless of the distance VL. The distance VL between the power receiving coil units 210 of the two vehicles 200a and 200b can be determined based on the detection result of the position of the power receiving coil unit 210 by the power receiving coil position detection unit 140.

[0084] In the fourth embodiment, when two vehicles 200a and 200b are traveling in the front and rear direction, the power transmission control unit 150 uses the primary coil 112 which is different from the power transmission implementation coils PSCa and PSCb used to transmit power to the two vehicles 200a and 200b as a cancellation coil CC, thereby reducing the leakage magnetic flux even when the distance between the two vehicles 200a and 200b is large.

[0085] E. Other implementation methods:

[0086] In addition to the above-described various embodiments, various embodiments described below can also be adopted.

[0087] like Fig.13 As shown, there is a case where power supply sections PSA1 and PSA2 are set on the driving lane RL12 and the opposite lane RL22, respectively. In such a case, when the vehicle 200 is traveling on the driving lane RL12, in order to reduce the leakage magnetic flux caused by the energization of the power transmission implementation coil PSC, the primary coil 112 of the opposite lane RL22, which is located near the power transmission implementation coil PSC, can also be used as a cancellation coil CC. Fig.13 In the example, the primary coil 112 arranged in the y direction with the power transmission implementation coil PSC is used as the cancellation coil CC. In this way, the leakage magnetic flux in the left and right directions of the vehicle 200 can be reduced. In this case, in the x direction, the cancellation coil CC can also be selected according to the method described in the various embodiments.

[0088] like Fig.14 As shown, it is also possible to assume that the power supply sections PSA1 and PSA2 are set in parallel on a plurality of driving lanes RL11 and RL12 having the same traveling direction. In this case, preferably, the leakage magnetic flux of each is reduced by setting a phase difference in power transmission in the primary coil 112 set in the first power supply section PSA1 and the primary coil 112 set in the second power supply section PSA2. Specifically, for example, the phase of the power transmission current of the primary coil 112 set in the first power supply section PSA1 and the phase of the power transmission current of the primary coil 112 set in the second power supply section PSA2 arranged in the y direction with the first power supply section PSA1 can be opposite phases with a difference of 180 degrees. In this way, the leakage magnetic flux in the direction perpendicular to the traveling direction of the driving lane can be reduced.

[0089] In addition, Fig.14 In the example of FIG. 1 , a shop SP and a parking lot PP are provided outside the sidewalk SW1, and a power supply pad PSP for contactless power supply when the vehicle is parked is provided in the parking lot PP. In this case, the primary coil of the power supply pad PSP for power supply during parking is used as a cancellation coil CC to reduce the leakage magnetic flux caused by power supply during driving in the power supply sections PSA1 and PSA2. In this case, for example, the contactless power supply device 100 ( Figure 1 )'s power transmission control unit 150 can utilize wireless communication to send an execution request for control to reduce leakage magnetic flux to the power supply pad PSP.

[0090] like Fig.15 As shown in FIG. 1 , when a plurality of vehicles 200a to 200c are simultaneously traveling in the same power supply area PSA and receiving power supply, the amount of power supply may differ for each vehicle. Fig.15 In the example, 10 kW of electricity is transmitted to the first vehicle 200a, 30 kW of electricity is transmitted to the second vehicle 200b, and 20 kW of electricity is transmitted to the third vehicle 200c. The difference in the amount of electricity transmitted may be caused by the difference in the capacity of the main battery 230 installed in each vehicle 200, the difference in the charge level (i.e., SOC) of the main battery 230, the difference in the slope during driving, etc. In this case, it is preferable to adjust the phase of each transmission current according to the amount of electricity transmitted to the multiple vehicles 200a~200c so as to reduce the leakage flux as a whole. For example, in Fig.15 In the example of , the phase of the power transmission current to the second vehicle 200b is preferably set to be opposite to the phase of the power transmission current to the first vehicle 200a and the third vehicle 200c. Such control can also be applied to a case where four or more vehicles 200 are simultaneously traveling in the same power supply area PSA and receiving power supply.

[0091] In the various embodiments, any one of the primary coils 112 is used to reduce the leakage flux, but the leakage flux may also be reduced using the secondary coil 212. Specifically, for example, when the vehicle 200 with a sufficiently high charge level (i.e., SOC) of the main battery 230 is traveling in the power supply section, the control device 290 of the vehicle 200 uses the power of the main battery 230 to flow current through the secondary coil 212, thereby reducing the leakage flux. In other words, as a leakage flux reduction process, at least one of the following processes can be performed: (a) a first process, in which the power transmission control unit 150 uses a specific primary coil CC among the multiple primary coils 112 that is different from the power transmission implementation coil PSC to reduce the leakage magnetic flux generated by energizing the power transmission implementation coil PSC; and (b) a second process, in which the control device 290 of the vehicle 200 reduces the leakage magnetic flux generated by energizing the power transmission implementation coil PSC by passing current through the secondary coil 212 without receiving power based on the secondary coil 212.

[0092] like Fig.16A As shown, a plurality of cutouts 114g may be provided at the magnetic yoke 114 of the primary coil 112 at a certain pitch P along the arrangement direction x of the primary coil 112. The cutouts 114g are gaps whose size along the arrangement direction x of the primary coil 112 is not zero. However, the gaps of the cutouts 114g may also be filled with non-magnetic materials. Fig.16AIn the example of , the pitch P of the cutout portion 114g is equal to the pitch of the primary coil 112. The cutout portion 114g is preferably provided at the center of the magnetic pole generated by energizing the primary coil 112. As described later, by providing the cutout portion 114g in the magnetic yoke 114, the leakage electromagnetic field can be reduced.

[0093] like Fig. 16B As shown, the magnetic resistance Rm of the magnetic yoke 114 including the cut-off portion 114g is given by the following equation.

[0094] [Mathematical formula 2]

[0095]

[0096] Here, A is the cross-sectional area of ​​the magnetic yoke 114, L is the length of the magnetic yoke 114 as the object of calculation of the magnetic resistance Rm, g is the cut width as the length of the cut portion 114g, μ0 is the magnetic permeability of a vacuum, μ1 is the relative magnetic permeability of air, μr is the relative magnetic permeability of the magnetic material forming the magnetic yoke 114, and μ' is the composite relative magnetic permeability. The cut width g is set to a non-zero value. The length L of the magnetic yoke 114 is preferably a value that is an integer multiple of the spacing of the cut portion 114g. The composite relative magnetic permeability μ' is equivalent to the relative magnetic permeability when the magnetic yoke 114 having the cut portion 114g is assumed to be formed of the same material.

[0097] like Fig. 16C As shown in FIG. 1 , the larger the cut width g of the magnetic yoke 114 is, the lower the composite relative magnetic permeability μ' is. Fig.16D As shown in FIG. 1 , if the synthetic relative permeability μ' is reduced, the leakage electromagnetic field can be reduced without significantly reducing the coupling coefficient between the primary coil 112 and the secondary coil 212. Therefore, preferably, the synthetic relative permeability μ' is formed to be less than 100. That is, Fig. 16C In the characteristic of the invention, the cut width g is preferably set to a value greater than the value Gm when the synthetic relative permeability μ' is 100. In this way, the leakage electromagnetic field can be reduced without excessively reducing the power supply efficiency. In addition, if the synthetic relative permeability μ' is reduced, the coupling coefficient between the primary coil 112 and the secondary coil 212 is also reduced, and the power supply efficiency is also reduced. Therefore, considering this point, the synthetic relative permeability μ' is preferably a value greater than 10, and more preferably a value greater than 50.

[0098] Compare Fig.17A and Fig. 17B It can be seen that by providing the cut-off portion 114g in the magnetic yoke 114, the leakage electromagnetic field can be reduced. Fig.17AAs shown, the main magnetic flux MF generated from the power transmission implementation coil PSC propagates in the magnetic yoke 114. In the case where there is no cut-off portion in the magnetic yoke 114 of the primary coil 112, the magnetic flux propagating in the magnetic yoke 114 is difficult to attenuate, so the main magnetic flux MF reaches far away. Therefore, the magnetic flux FX1 propagating in the magnetic yoke 114 caused by the main magnetic flux MF is quite large. On the other hand, the magnetic flux FX2 generated by the leakage magnetic flux LF flowing through the air and propagating in the magnetic yoke 114 is opposite to the direction of the magnetic flux FX1 generated by the main magnetic flux MF. In the case where the observation point MP of the leakage electromagnetic field exists at a position where the magnetic fluxes FX1 and FX2 flow, it is possible to measure a considerable leakage electromagnetic field. In addition, at the observation point MP of the leakage magnetic flux, there may be two magnetic fluxes in different directions, which are difficult to reduce using a cancellation coil or the like. In addition, the magnetic flux FX1 in the main magnetic flux propagates to a far distance via the magnetic yoke 114, so the leakage magnetic flux may become larger.

[0099] In contrast, Fig. 17B As shown, by providing the cut-off portion 114g in the magnetic yoke 114, the magnetic flux FX1 caused by the main magnetic flux MF and propagating in the magnetic yoke 114 can be reduced, so that the direction of the magnetic flux can be roughly in one direction near the observation point MP of the leakage electromagnetic field. As a result, the leakage electromagnetic field can be sufficiently reduced by the cancellation coil CC.

[0100] like Fig.18 As shown, it can also be obtained from Fig.16A In the structure shown, the primary coils 112 are thinned out so that the number of primary coils 112 is halved. That is, the primary coils 112 may be arranged at a pitch that is twice the pitch P of the plurality of cut portions 114g. Such a structure will be described further below.

[0101] exist Fig.19 In the example, the primary coil 112 is a DD coil composed of a first coil 112d1 and a second coil 112d2. The first coil 112d1 and the second coil 112d2 are wound in opposite directions and in contact with each other. In addition, in this example, a group of primary coils 112 is driven by a power transmission circuit 120, that is, an inverter. Therefore, when a group of primary coils 112 as DD coils is selected as a cancellation coil CC and energized, one of the first coil 112d1 and the second coil 112d2 is excited to the S pole, and the other is excited to the N pole. Fig.19In the embodiment, a front cancellation coil CC1 located in front of the vehicle in the direction x of travel and a rear cancellation coil CC2 located in the rear of the vehicle in the direction x of travel are used. At this time, four magnetic poles are generated by the two sets of cancellation coils CC1 and CC2, and magnetic fluxes FC1 and FC2 propagating in the air are generated accordingly. In addition, leakage flux LF is also generated by power transmission. The leakage flux LF generated in the power transmission is only in one direction, but the magnetic fluxes FC1 and FC2 generated by the cancellation current are in opposite directions to each other. In addition, since the magnetic fluxes FC1 and FC2 are generated in opposite directions to each other, one of the magnetic fluxes FC1 and FC2 is in the same direction as the magnetic flux generated from the secondary coil 212, and the other is in the opposite direction to the magnetic flux generated from the secondary coil 212. Therefore, there will be areas where the magnetic fluxes strengthen and weaken each other, and the leakage electromagnetic field will not be reduced.

[0102] On the other hand, Fig. 20 In the example, the first coil 112d1 and the second coil 112d2 in a set of primary coils 112 constituting a DD coil are driven by different power transmission circuits 120d1 and 12d2, respectively. In this case, as the front cancellation coil CC1 and the rear cancellation coil CC2, it is preferred to use only one of the two coils 112d1 and 112d2 constituting the DD coil. In this case, the selection of the coil and the direction of the cancellation current can be set so that one of the front cancellation coil CC1 and the rear cancellation coil CC2 is the S pole and the other is the N pole. In this way, Fig.19 In comparison, the magnetic flux FC propagating in the air caused by the energization of the cancellation coils CC1 and CC2 becomes less, thereby reducing the leakage magnetic flux. In addition, since the magnetic flux FC propagating in the air caused by the energization of the cancellation coils CC1 and CC2 is opposite to the direction of the magnetic flux LF generated in the power receiving coil unit 210 and cancels each other, the leakage electromagnetic field is reduced.

[0103] Fig.21 The structure shown is from Fig. 20 The structure of the primary coil 112 is similar to that of the primary coil 112, in which one of the two coils constituting the DD coil is omitted. Fig.18 That is, the primary coil 112 is arranged at a pitch twice the pitch P of the plurality of cutouts 114g. According to this structure, the same Fig. 20 The effect is roughly the same as that of the structure. In order to reverse the magnetic poles, the current flowing through the front cancellation coil CC1 and the rear cancellation coil CC2 is set to have a phase difference of 180°. Moreover, in this structure, since the number of primary coils 112 is small, the number of power transmission circuits 120 can be reduced.

[0104] Fig.22A Shown in Fig. 20The amplitude and phase of the current flowing through the primary coil 112 and the secondary coil 212 in the structure. In this example, two sets of primary coils 112, each configured as a DD coil, are used as power transmission implementation coils PSC1 and PSC2. The secondary coil 212 is a two-phase coil consisting of an A-phase coil 212a and a B-phase coil 212b. Fig.22A As shown in the lower part of , the currents I1 and I2 of the power transmission implementation coils PSC1 and PSC2 have equal amplitudes A1 and phases. The current Ia of the A-phase coil 212a of the secondary coil 212 and the current Ib of the B-phase coil 212b have equal amplitudes A2, but are 180 degrees apart in phase. In addition, the phases of the currents Ia and Ib of the secondary coil 212 are offset by 90 degrees from the phases of the currents I1 and I2 of the power transmission implementation coils PSC1 and PSC2. The front cancellation coil CC1 and the rear cancellation coil CC2 can be configured by using coils with different winding directions to be energized with the same phase, or by using coils with the same winding direction to be energized with a phase difference of 180 degrees, thereby reducing the leakage electromagnetic field.

[0105] like Fig. 22B and Fig. 22C As shown, in Fig.22A In the structure, the leakage electromagnetic field G1 when the cancellation coils CC1 and CC2 are used can be reduced from the leakage electromagnetic field G0 when the cancellation coils CC1 and CC2 are not used. As shown in the above figure, the leakage electromagnetic field along the vehicle travel direction and the vehicle width direction changes according to the current phase of the cancellation coils CC1 and CC2. That is, Fig. 22B As shown in FIG. 1 , when the phase difference between the current phase of the cancellation coils CC1 and CC2 and the current phase of the A-phase coil 212a of the secondary coil 212 is 0 degrees, the leakage electromagnetic field in the vehicle travel direction is minimum. Fig. 22C As shown, when the phase difference between the current phase of the cancellation coils CC1 and CC2 and the current phase of the A-phase coil 212a of the secondary coil 212 is 180 degrees, the leakage electromagnetic field in the vehicle width direction is minimized. For example, in the case where it is desired to reduce the leakage electromagnetic field in the vehicle width direction, it is preferred to set the current phase of the cancellation coils CC1 and CC2 to have a phase difference of 180 degrees ± 10 degrees from the current phase of the A-phase coil 212a.

[0106] Fig.23A Shown in Fig.21 The amplitude and phase of the current flowing through the primary coil 112 and the secondary coil 212 in the structure. In this example, the two primary coils 112, which are each configured as a single coil other than a DD coil, are used as the power transmission implementation coils PSC1 and PSC2. The secondary coil 212 is a two-phase coil consisting of an A-phase coil 212a and a B-phase coil 212b. Fig.23AAs shown in the lower part of the figure, the currents I1 and I2 of the power transmission coils PSC1 and PSC2 and the currents Ia and Ib of the secondary coil 212 are Fig.22A The phase of the situation is different.

[0107] like Fig. 23B As shown, when the phase difference between the current phase of the cancellation coils CC1 and CC2 and the current phase of the A-phase coil 212a of the secondary coil 212 is set to 90 degrees, the leakage electromagnetic field in the vehicle travel direction is minimized. Fig.23C As shown, when the phase difference between the current phase of the cancellation coils CC1 and CC2 and the current phase of the A-phase coil 212a of the secondary coil 212 is 270 degrees, the leakage electromagnetic field in the vehicle width direction is minimized. For example, in the case where it is desired to reduce the leakage electromagnetic field in the vehicle width direction, it is preferred to set the current phase of the cancellation coils CC1 and CC2 to have a phase difference of 270 degrees ± 10 degrees from the current phase of the A-phase coil 212a.

[0108] The present disclosure is not limited to the above-described embodiments and their modifications, and can be implemented in various forms within the scope of the gist thereof. In addition, the above-described various characteristic structures can be arbitrarily combined and adopted as long as they do not contradict each other.

Claims

1. A contactless power supply device for supplying power to a vehicle in a contactless manner while the vehicle is running, characterized in that: include: A plurality of primary coils, wherein the plurality of primary coils are arranged on the road; a power transmission control unit that uses a portion of the primary coils among the plurality of primary coils as power transmission implementation coils and performs power transmission from the power transmission implementation coils to a secondary coil installed in the vehicle; as well as a coil position detection unit for detecting a gap between the power transmission implementation coil and the secondary coil; The power transmission control unit uses a specific primary coil among the plurality of primary coils that is different from the power transmission implementation coil to reduce leakage magnetic flux generated by energizing the implementation coil. The power transmission control unit determines a distance between the specific primary coil and the power transmission implementation coil based on the gap when selecting the specific primary coil from the plurality of primary coils.

2. The contactless power supply device according to claim 1, characterized in that: The power transmission control unit controls the circuit element connected to the specific primary coil so that a current in a direction that reduces the leakage magnetic flux flows through the specific primary coil.

3. The contactless power supply device according to claim 2, characterized in that: The power transmission control unit generates a current flowing through the specific primary coil at a phase suitable for reducing the leakage magnetic flux.

4. The contactless power supply device according to claim 3, characterized in that: The power transmission control unit sets the current flowing through the specific primary coil to be smaller than the current flowing through the power transmission implementation coil.

5. The contactless power supply device according to claim 4, characterized in that: The contactless power supply device further includes a leakage magnetic flux detection unit for detecting the leakage magnetic flux. The power transmission control unit adjusts the current flowing through the specific primary coil based on the leakage magnetic flux detected by the leakage magnetic flux detection unit.

6. The contactless power supply device according to any one of claims 2 to 3, characterized in that: The power transmission control unit uses, as the specific primary coil, a primary coil that transmits power to another vehicle different from the vehicle.

7. The contactless power supply device according to claim 1, characterized in that: The power transmission control unit reduces the leakage magnetic flux by short-circuiting both ends of the specific primary coil.

8. The contactless power supply device according to any one of claims 1 to 4, characterized in that: A magnetic yoke is provided on the plurality of primary coils. The magnetic yoke has a plurality of cutout portions provided at a constant pitch along an arrangement direction of the plurality of primary coils.

9. The contactless power supply device according to claim 8, characterized in that: The cutoff portion is provided at a position at the center of a magnetic pole generated by energizing the primary coil.

10. The contactless power supply device according to claim 9, characterized in that: The cut-off portion is formed so that the combined relative magnetic permeability of the magnetic yoke including the cut-off portion is less than 100.

11. The contactless power supply device according to claim 8, characterized in that: The plurality of primary coils are arranged at a pitch that is twice the pitch of the plurality of cutout portions.

12. A contactless power supply device for supplying power to a vehicle in a contactless manner while the vehicle is running, characterized in that: include: A plurality of primary coils, wherein the plurality of primary coils are arranged on the road; as well as a power transmission control unit that uses a portion of the primary coils among the plurality of primary coils as a power transmission implementation coil and performs power transmission from the power transmission implementation coil to a secondary coil installed in the vehicle, The power transmission control unit uses a specific primary coil among the plurality of primary coils that is different from the power transmission implementation coil to reduce leakage magnetic flux generated by energizing the implementation coil. Each primary coil is a DD coil consisting of two coils arranged adjacent to each other with winding directions opposite to each other. The two coils constituting the DD coil are driven by two inverters respectively, The specific primary coils include a front cancellation DD coil located in front of the vehicle in the direction of travel and a rear cancellation DD coil located in the rear of the vehicle in the direction of travel. When the power transmission control unit uses the front cancellation DD coil and the rear cancellation DD coil at the same time to reduce the leakage magnetic flux, it performs power supply so that only one of the two coils constituting the front cancellation DD coil and only one of the two coils constituting the rear cancellation DD coil form an N pole and an S pole.

13. A contactless power supply device for supplying power to a vehicle in a contactless manner while the vehicle is running, characterized in that: include: A plurality of primary coils, wherein the plurality of primary coils are arranged on the road; as well as a power transmission control unit that uses a portion of the primary coils among the plurality of primary coils as a power transmission implementation coil and performs power transmission from the power transmission implementation coil to a secondary coil installed in the vehicle, The power transmission control unit uses a specific primary coil among the plurality of primary coils that is different from the power transmission implementation coil to reduce leakage magnetic flux generated by energizing the implementation coil. The power transmission control unit uses, as the specific primary coil, a primary coil that transmits power to another vehicle different from the vehicle.

14. The contactless power supply device according to claim 13, characterized in that: A magnetic yoke is provided on the plurality of primary coils. The magnetic yoke has a plurality of cutout portions provided at a constant pitch along an arrangement direction of the plurality of primary coils.

15. A contactless power supply system, wherein the contactless power supply system uses a plurality of primary coils disposed on a road and a secondary coil mounted on a vehicle to supply power to the vehicle in a contactless manner while the vehicle is traveling, wherein: include: a power transmission control unit that uses a portion of the primary coils of the plurality of primary coils as power transmission implementation coils and performs power transmission from the power transmission implementation coils; a control device that controls the operation of the secondary coils; and a coil position detection unit for detecting a gap between the power transmission implementation coil and the secondary coil; When the power transmission control unit selects a specific primary coil from the plurality of primary coils, the power transmission control unit determines a distance between the specific primary coil and the power transmission implementation coil based on the gap. The contactless power supply system performs at least one of the following processes: (a) a first process in which the power transmission control unit uses a specific primary coil different from the power transmission implementation coil among the plurality of primary coils to reduce a leakage magnetic flux generated by energizing the power transmission implementation coil; as well as (b) A second process in which the control device reduces leakage magnetic flux generated by energizing the power transmission coil by passing current through the secondary coil when power reception by the secondary coil is not performed.

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