Overground power supply device and wiring

Abstract

A ground power supply device (1) for contactlessly transmitting power to a vehicle (5) is provided with: a plurality of resonant circuits (20); and one power supply source that supplies AC power having the same frequency to all of the resonant circuits. Each resonance circuit has: a coil 23 that is embedded in the road and transmits power in a non-contact manner; and a wiring (22) that connects each coil and a power supply source. The wiring of each resonant circuit is formed to have a length at least partially different from that of the wiring of the other resonant circuit, and an inductance parasitic in the wiring due to the difference in the length is at least partially different from that of the wiring of the other resonant circuit. The resonant circuits are further provided with capacitors having different capacitances such that the resonant frequencies of all the resonant circuits are the same even if parasitic inductances in the wiring differ.

Description

Technical Field

[0001] The present disclosure relates to an above-ground power supply device and wiring. Background Art

[0002] A ground power supply device is known, which has multiple coils for contactlessly transmitting power and a power supply for supplying power to the coils, and these coils and the power supply are respectively connected by conductors (Japanese Patent Publication No. 2019-526219). Summary of the invention

[0003] Since the distance between the power source and the coil is different for each coil, the length of the conductor connecting the power source and the coil is different from each other. Since the parasitic inductance in the conductor is different according to the length of the conductor, the resonant frequency is different from each other in each resonant circuit including the conductor and the coil of different lengths.

[0004] In view of the above-mentioned problems, an object of the present disclosure is to suppress differences in resonance frequencies among a plurality of coils connected to one power supply.

[0005] The gist of the present disclosure is as follows.

[0006] (1) A ground power supply device that transmits power to a vehicle without contact, The ground power supply device comprises: a plurality of resonant circuits; and a power supply source for supplying AC power having the same frequency to all the resonant circuits. Each resonant circuit includes: a coil buried in the road and used for contactless power transmission; and wiring connecting each coil and the power supply source. The wiring of each resonant circuit is formed to have a length at least partially different from that of the wiring of the other resonant circuits, and the inductance parasitic in the wiring due to the difference in length is at least partially different from that of the wiring of the other resonant circuits, The resonant circuits further include capacitors having different capacitances so that the resonant frequencies of all the resonant circuits are the same even if the parasitic inductances in the wirings are different. (2) In the ground power supply device described in (1) above, the capacitor has a capacitance such that even if parasitic inductance in the wiring is different, the resonant frequency of all the resonant circuits becomes the same as the frequency of the AC power. (3) In the ground power supply device described in (1) or (2) above, wirings of the plurality of resonance circuits including the plurality of coils arranged adjacent to each other have the same length. (4) The ground power supply device according to any one of (1) to (3) above, The wiring has: a first portion having the same length in all the resonant circuits; and a second portion having partially different lengths between the resonant circuits, The second portion is provided with the capacitor. (5) According to the ground power supply device described in (4) above, the capacitors provided in the plurality of second portions having the same length have the same capacitance. (6) In the ground power supply device described in (4) or (5) above, the first portion does not have a capacitor. (7) According to any one of the above-mentioned (4) to (6), the first part is connected to the coil, the second part is connected to the power supply source, and a plurality of the second parts having the same length are connected to the first part via the same connector. (8) The ground power supply device according to any one of (1) to (7) above, The wiring is at least partially formed by connecting a plurality of wiring modules in series, each of the plurality of wiring modules having a cable having the same length and a capacitor connected to the cable, The capacitor of each wiring module has a capacitance that cancels the influence of the parasitic inductance of the cable of the wiring module on the resonant frequency generated in the coil at the frequency of the AC power. The resonance circuit having wirings of different lengths has the wirings of different lengths because the number of wiring blocks constituting the resonance circuit is different. (9) According to the above-ground power supply device described in (8), the length of the cable of the wiring module is equal to an integral multiple of the interval between adjacent coils. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a diagram schematically showing the ground power supply device and the vehicle according to the first embodiment. Figure 2 It is a diagram schematically showing the configuration of a ground power supply device and a vehicle according to the first embodiment. Figure 3 It is a diagram schematically showing the configuration of the ground power supply device according to the first embodiment. Figure 4 The structure of the ground power supply device according to a modification of the first embodiment is schematically shown. Figure 3 Same picture. Figure 5 The structure of the ground power supply device according to the second embodiment is schematically shown. Figure 3 and Figure 4 Same picture. Figure 6 The structure of the ground power supply device according to the third embodiment is schematically shown. Figures 3 to 5 Same picture. Figure 7 It is a diagram schematically showing the configuration of each wiring module. Figure 8 It is a diagram schematically showing the configuration of a ground power supply device according to a fourth embodiment. DETAILED DESCRIPTION

[0008] Hereinafter, the embodiment will be described in detail with reference to the drawings. In the following description, the same reference numerals are given to the same components.

[0009] First embodiment <Overview of Ground Power Supply Equipment> Reference Figure 1 hereinafter, an overview of the ground power supply device 1 according to the first embodiment and the vehicle 5 capable of receiving electric power from the ground power supply device 1 will be described. Figure 1 1 is a diagram schematically showing a ground power supply device 1 and a vehicle 5 according to the first embodiment. The ground power supply device 1 transmits power to the vehicle 5 by contactless power transmission through magnetic field resonance coupling (magnetic field resonance). In particular, in the present embodiment, contactless power transmission is performed from the ground power supply device 1 to the vehicle 5 while the vehicle 5 is traveling.

[0010] The term "running" refers to a state where the vehicle 5 is on the road for traveling. Therefore, the term "running" includes not only a state where the vehicle 5 is actually traveling at any speed greater than zero, but also a state where the vehicle 5 is stopped on the road, for example, due to waiting for a traffic light.

[0011] The ground power supply device 1 includes a plurality of power transmission units 21 buried in the road (underground) on which the vehicle 5 travels. Figure 1 As shown, in the present embodiment, the power transmission units 21 are arranged at predetermined intervals along the lanes 100 at the center of the lanes 100 on which the vehicles 5 travel.

[0012] <Configuration of ground power supply equipment> Next, refer to Figure 2 , the structure of the ground power supply device 1 is briefly described. Figure 2 Schematically shows the structure of the ground power supply device 1 and the vehicle 5. Figure 2As shown, the ground power supply device 1 includes a power supply 2, a power supply unit 10, a plurality of power transmission side resonant circuits 20 including a power transmission unit 21, and a controller 30. The power transmission side resonant circuit 20 including the power transmission unit 21 is buried in the road (underground). On the other hand, the power supply unit 10 and the controller 30 may be buried in the road, or may be arranged in other places different from the road (including the ground). In this embodiment, one power supply unit 10 is connected to a plurality of power transmission side resonant circuits 20.

[0013] The power source 2 supplies power to the power transmission unit 21 via the power source unit 10. The power source 2 is, for example, a commercial AC power source that supplies single-phase AC power. Alternatively, the power source 2 may be another AC power source that supplies three-phase AC power, or a DC power source such as a fuel cell.

[0014] The power supply unit 10 converts the AC power supplied from the power supply 2 into high-frequency AC power for supplying to the power transmission side resonance circuit 20. The power supply unit 10 includes a power transmission side rectification circuit 11 and a converter 12. In the power supply unit 10, the AC power supplied from the power supply 2 is rectified in the power transmission side rectification circuit 11 and converted into a DC current, and the DC current is converted into AC power in the converter 12. The power supply 2 and the power supply unit 10 function as a power supply source for supplying AC power to the power transmission side resonance circuit 20.

[0015] The power transmission side rectifier circuit 11 is electrically connected to the power supply 2 and the converter 12. The power transmission side rectifier circuit 11 rectifies the AC power supplied from the power supply 2 and converts it into DC power, and supplies the DC power to the converter 12. The power transmission side rectifier circuit 11 is, for example, an AC / DC converter. In the present embodiment, one power transmission side rectifier circuit 11 is provided in one power supply unit 10. In addition, when the power supply 2 is a DC power supply, the power transmission side rectifier circuit 11 may be omitted.

[0016] The converter 12 is electrically connected to the power transmission side rectifier circuit 11 and the power transmission side resonant circuit 20. The converter 12 converts the DC power supplied from the power transmission side rectifier circuit 11 into AC power (high-frequency AC power) having a higher frequency than the AC power of the power source 2, and supplies the high-frequency AC power to the power transmission side resonant circuit 20. In the present embodiment, the power supply unit 10 has a number of converters 12 corresponding to the power transmission side resonant circuits 20. Each converter 12 is connected to a corresponding and different one of the power transmission side resonant circuits 20. In addition, each converter 12 supplies the power transmission side resonant circuit 20 with the same frequency as each other. Therefore, the power supply unit 10 supplies the same frequency of AC power to all the power transmission side resonant circuits 20.

[0017] The power transmission side resonance circuit 20 includes a power transmission unit 21 and wiring 22. The power transmission side resonance circuit 20 is connected to the power supply unit 10, and generates an alternating magnetic field when high frequency AC power is supplied from the power supply unit 10.

[0018] The power transmission unit 21 includes a power transmission side coil 23 and a power transmission side capacitor 24. When current flows through the power transmission side coil 23, a magnetic field that can transmit power contactlessly is generated. The power transmission side coil 23 and the power transmission side capacitor 24 constitute a resonator. Various parameters of the power transmission side coil 23 and the power transmission side capacitor 24 (the outer diameter and inner diameter of the power transmission side coil 23, the number of turns of the power transmission side coil 23, the capacitance of the power transmission side capacitor 24, etc.) are determined in such a way that the resonant frequency of the power transmission unit 21 becomes a prescribed set value. The prescribed set value is, for example, 10kHz to 100GHz, and preferably 85kHz determined according to the SAE TIRJ2954 standard as a frequency band for contactless power transmission. In addition, in the present embodiment, all power transmission units 21 are configured so that the various parameters of the power transmission side coil 23 and the power transmission side capacitor 24 are the same as each other. In other words, all power transmission units 21 have the same structure.

[0019] As described above, the power transmission unit 21 is buried in the road, and the power transmission side coil 23 and the power transmission side capacitor 24 are also buried in the road. The power transmission unit 21 is set in the center of the lane where the vehicle 5 passes so that the center of the power transmission side coil 23 is located in the center of the lane. When high-frequency power is supplied from the converter 12 to the power transmission unit 21 via the wiring 22, the power transmission side coil 23 of the power transmission unit 21 generates an AC magnetic field for power transmission.

[0020] The wiring 22 is used to connect the converter 12 of the power supply unit 10 and the power transmission unit 21 (i.e., the power transmission side coil 23). In the present embodiment, the ground power supply device 1 has a plurality of power transmission units 21, and has a plurality of converters 12 corresponding to different power transmission units 21. Each wiring 22 connects one converter 12 to one power transmission unit 21 corresponding thereto.

[0021] The controller 30 is, for example, a general-purpose computer, and performs various controls on the ground power supply device 1. For example, the controller 30 is electrically connected to the converter 12 of the power supply unit 10, and controls the converter 12 in order to control the power transmission by the power transmission unit 21. Specifically, for example, the controller 30 determines that the vehicle 5 having the power receiving device 50 is traveling on the power transmission unit 21 above based on the output from an arbitrary sensor (not shown), and controls the converter 12 in a manner that supplies power to the determined power transmission unit 21. The controller 30 has: a processor that performs various processes; and a memory that stores programs for causing the processor to perform various processes and various data used by the processor when performing various processes.

[0022] <Vehicle Configuration> Next, refer to Figure 2 , the structure of the vehicle 5 is briefly described. Figure 2 As shown, the vehicle 5 has a motor 41, a battery 42, a power control unit (PCU) 43, a power receiving device 50, and an electronic control unit (ECU) 45. The vehicle 5 is an electric vehicle (BEV) in which the motor 41 drives the vehicle 5, or a hybrid vehicle (HEV) in which the motor 41 and an internal combustion engine drive the vehicle 5.

[0023] The motor 41 is, for example, an AC synchronous motor, and functions as a motor and a generator. When the motor 41 functions as a motor, it drives the electric power stored in the battery 42 as a power source. The output of the motor 41 is transmitted to the wheels via the speed reducer and the axle. On the other hand, when the vehicle 5 decelerates, the motor 41 is driven by the rotation of the wheels, and the motor 41 functions as a generator to generate regenerative electric power.

[0024] The battery 42 is composed of a rechargeable secondary battery, such as a lithium-ion battery, a nickel-metal hydride battery, etc. The battery 42 stores the power required for the vehicle 5 to travel (for example, the driving power of the motor 41). The battery 42 is charged when the power received by the power receiving device 50 is supplied from the power transmission unit 21. In addition, when the regenerative power generated by the motor 41 is supplied to the battery 42, the battery 42 is charged. If the battery 42 is charged, the state of charge (SOC: State Of Charge) of the battery 42 is restored. In addition, the battery 42 can also be charged by an external power source other than the ground power supply device 1 via a charging port provided in the vehicle 5.

[0025] The PCU 43 is electrically connected to the battery 42 and the motor 41. The PCU 43 has a converter, a boost converter, and a DC / DC converter. The converter converts the DC power supplied from the battery 42 into AC power, and supplies the AC power to the motor 41. On the other hand, the converter converts the AC power (regenerative power) generated by the motor 41 into DC power, and supplies the DC power to the battery 42. When the power stored in the battery 42 is supplied to the motor 41, the boost converter boosts the voltage of the battery 42 as needed. When the power stored in the battery 42 is supplied to electronic equipment such as headlights, the DC / DC converter steps down the voltage of the battery 42.

[0026] The power receiving device 50 receives electric power from the power transmitting unit 21, and supplies the received electric power to the battery 42. The power receiving device 50 includes a power receiving side resonance circuit 51, a power receiving side rectification circuit 54, and a charging circuit 55.

[0027] The receiving-side resonant circuit 51 is arranged at the bottom of the vehicle 5 so that the distance from the road surface is small. The receiving-side resonant circuit 51 has the same configuration as the power transmission unit 21, and has a receiving-side coil 52 and a receiving-side capacitor 53. The receiving-side coil 52 is arranged so that a current flows through the receiving-side coil 52 after a magnetic field is generated around it. The receiving-side coil 52 and the receiving-side capacitor 53 constitute a resonator. Various parameters of the receiving-side coil 52 and the receiving-side capacitor 53 (the outer diameter and inner diameter of the receiving-side coil 52, the number of turns of the receiving-side coil 52, the capacitance of the receiving-side capacitor 53, etc.) are determined so that the resonant frequency of the receiving-side resonant circuit 51 coincides with the resonant frequency of the power transmission unit 21. In addition, if the deviation between the resonant frequency of the power receiving-side resonant circuit 51 and the resonant frequency of the power transmission unit 21 is small, for example, the resonant frequency of the power receiving-side resonant circuit 51 is within the range of ±20% of the resonant frequency of the power transmission unit 21, the resonant frequency of the power receiving-side resonant circuit 51 does not necessarily have to coincide with the resonant frequency of the power transmission unit 21.

[0028] like Figure 2 As shown in FIG. 1 , when the power-receiving-side resonance circuit 51 and the power-transmitting unit 21 face each other, an AC magnetic field is generated by the power-transmitting unit 21, and the vibration of the AC magnetic field is transmitted to the power-receiving-side resonance circuit 51 which resonates at the same resonance frequency as the power-transmitting unit 21. As a result, an induced current flows in the power-receiving-side resonance circuit 51 due to electromagnetic induction, and an induced electromotive force is generated in the power-receiving-side resonance circuit 51 due to the induced current. That is, the power-transmitting unit 21 transmits power to the power-receiving-side resonance circuit 51, and the power-receiving-side resonance circuit 51 receives power from the power-transmitting unit 21.

[0029] The receiving-side rectifier circuit 54 is electrically connected to the receiving-side resonance circuit 51 and the charging circuit 55. The receiving-side rectifier circuit 54 rectifies the AC power supplied from the receiving-side resonance circuit 51, converts it into DC power, and supplies the DC power to the charging circuit 55. The receiving-side rectifier circuit 54 is, for example, an AC / DC converter.

[0030] The charging circuit 55 is electrically connected to the power receiving side rectifier circuit 54 and the battery 42. The charging circuit 55 converts the DC power supplied from the power receiving side rectifier circuit 54 into the voltage level of the battery 42 and supplies it to the battery 42. When the power transmitted from the power transmission unit 21 is supplied to the battery 42 via the power receiving device 50, the battery 42 is charged. The charging circuit 55 is, for example, a DC / DC converter.

[0031] The ECU 45 performs various controls on the vehicle 5. For example, the ECU 45 is electrically connected to the charging circuit 55 of the power receiving device 50, and controls the charging circuit 55 to control the charging of the battery 42 by the power transmitted from the power transmission unit 21. In addition, the ECU 45 is electrically connected to the PCU 43, and controls the PCU 43 to control the supply and reception of power between the battery 42 and the motor 41.

[0032] <Transmission-side resonance circuit> Next, refer to Figure 3 , the structure of the power transmission side resonance circuit 20 will be described. Figure 3 Schematically shows the configuration of the ground power supply device 1. In particular, Figure 3 2 shows a state where a plurality of power transmission side resonance circuits 20 are connected to one power supply unit 10. Figure 3 In the figure, only one power-transmitting-side resonant circuit 20 among the plurality of power-transmitting-side resonant circuits 20 is denoted by reference numeral 20 .

[0033] like Figure 3 As shown, a plurality of power transmission units 21 connected to one power supply unit 10 are arranged in a row along the lane in the road. Each power transmission unit 21 and the power supply unit 10 are connected via wiring 22 of a different power transmission side resonance circuit 20. The wiring 22 connecting each power transmission unit 21 and the power supply unit 10 has two conductors in which current flows in opposite directions.

[0034] In addition, if Figure 3 As shown, the intervals between each of the plurality of power transmission units 21 arranged in a row and one power supply unit 10 are different from each other. In addition, in the present embodiment, each of the power transmission units 21 and the power supply unit 10 is connected by a single wiring 22 arranged without any slack between them. Therefore, the plurality of wirings 22 connecting each of the power transmission units 21 and the power supply unit 10 have different lengths from each other. That is, in the present embodiment, the wiring 22 of each power transmission side resonance circuit 20 has a length different from the length of the wiring 22 of other power transmission side resonance circuits 20.

[0035] Here, since the wirings 22 of the power transmission side resonance circuit 20 have different lengths, different parasitic inductances are parasitic in each of the wirings 22. In particular, the longer the length of the wiring 22, the greater the parasitic inductances parasitic in the wiring 22. If different parasitic inductances are parasitic in each of the wirings 22, the resonance frequencies of the power transmission side resonance circuits 20 having the wirings 22 are different. If the resonance frequencies of the power transmission side resonance circuits 20 are different, the resonance frequencies of some of the power transmission side resonance circuits 20 become different from the frequency of the AC power supplied by the power supply unit 10. In addition, if the resonance frequencies of the power transmission side resonance circuits 20 are different, the resonance frequencies of some of the power transmission side resonance circuits 20 become different from the resonance frequencies of the power reception side resonance circuit 51 of the vehicle 5. When the resonance frequencies of the power transmission side resonance circuits 20 become different from the frequency of the AC power and the resonance frequencies of the power reception side resonance circuits 51, the transmission efficiency in the contactless power transmission is reduced.

[0036] Therefore, a resonance compensation capacitor 25 is provided in the power transmission side resonance circuit 20 involved in this embodiment. In this embodiment, the resonance compensation capacitor 25 is connected in series with the wiring 22 in the middle of the wiring 22. In other words, in this embodiment, each wiring 22 has a resonance compensation capacitor 25. In addition, in this embodiment, the resonance compensation capacitor 25 is connected to one of the two conductors of each wiring 22.

[0037] The resonance compensation capacitor 25 has different capacitances corresponding to the lengths of the wiring 22 of the power transmission side resonance circuit 20 provided with the resonance compensation capacitor 25. Specifically, the capacitance of the resonance compensation capacitor 25 decreases as the length of the wiring 22 increases. More specifically, the resonance compensation capacitor 25 has such capacitance that the resonance frequency of the power transmission side resonance circuit 20 is the same as the frequency of the AC power supplied by the power supply unit 10 even if the parasitic inductances parasitic in the wiring 22 of the power transmission side resonance circuit 20 are different from each other.

[0038] According to the present embodiment, even when the length of the wiring 22 in each power transmission side resonance circuit 20 is different and the parasitic inductance in the wiring 22 is different, the resonance frequency of the power transmission side resonance circuit 20 can be made the same as the frequency of the AC power supplied by the power supply unit 10. Therefore, according to the present embodiment, even in this case, the resonance frequencies of all the power transmission side resonance circuits 20 can be made substantially the same, and the resonance frequencies of all the power transmission side resonance circuits 20 can be made the same as the resonance frequency of the power receiving side resonance circuit 51 of the vehicle 5. Therefore, according to the present embodiment, the transmission efficiency between the power transmission unit 21 and the power receiving side resonance circuit 51 can be improved.

[0039] <Modification> In the above embodiment, the resonance compensation capacitor 25 is connected in series with the wiring 22 in the middle of the wiring 22. However, the resonance compensation capacitor 25 may be provided between the wiring 22 and the power transmission unit 21, or between the wiring 22 and the converter 12 of the power supply unit 10. Alternatively, the resonance compensation capacitor 25 only needs to be connected in series within the power transmission side resonance circuit 20, and may be provided within the power transmission unit 21 (for example, between the power transmission side coil 23 and the power transmission side capacitor 24 of the power transmission unit 21).

[0040] In addition, in the above-mentioned embodiment, one resonance compensation capacitor 25 is provided in one power transmission side resonance circuit 20. However, a plurality of resonance compensation capacitors 25 may be provided in one power transmission side resonance circuit 20. For example, in the above-mentioned embodiment, the resonance compensation capacitor 25 is connected to one of the two conductors in each wiring 22. However, the two conductors of each wiring 22 may be connected to each of the resonance compensation capacitors 25. In this case, the capacitance of these resonance compensation capacitors 25 is also set to a value that makes the resonance frequency of the power transmission side resonance circuit 20 the same as the frequency of the AC power supplied by the power supply unit 10.

[0041] In the above embodiment, all the wirings 22 connected to the power supply unit 10 have different lengths from each other. However, some of the wirings 22 may have the same length as each other. Figure 4 The structure of the ground power supply device 1 according to a modification of the first embodiment is schematically shown. Figure 3 The same picture. Figure 4 In the example shown, the wiring of the plurality of power transmission side resonant circuits 20 (specifically, the power transmission side resonant circuits 20 including the four power transmission units 21 on the right, the power transmission side resonant circuits 20 including the four power transmission units 21 in the center, and the power transmission side resonant circuits 20 including the four power transmission units 21 on the left) including the plurality of power transmission units 21 (power transmission side coils 23) arranged adjacently has the same length. The resonance compensation capacitors 25 in the power transmission side resonant circuits 20 having the wiring 22 of the same length have the same capacitance. As a result, the number of changes in the wiring length and the number of changes in the resonance compensation capacitors 25 can be reduced, the manufacturing cost can be reduced, and the ground power supply device 1 can be easily installed.

[0042] As described above, in the present embodiment and its variants, the wiring 22 of the power-transmitting-side resonant circuit 20 is formed to have a length that is at least partially different from the wiring 22 of other power-transmitting-side resonant circuits 20, and the parasitic inductance in the wiring 22 due to the difference in length is at least partially different from the wiring 22 of other power-transmitting-side resonant circuits 20.

[0043] Second embodiment Next, refer to Figure 5, a ground power supply device 1 according to a second embodiment is described. The configuration of the ground power supply device 1 according to the second embodiment is basically the same as that of the ground power supply device 1 according to the first embodiment. The following description will focus on the parts that are different from the configuration of the ground power supply device 1 according to the first embodiment.

[0044] Figure 5 The structure of the ground power supply device 1 according to the second embodiment is schematically shown. Figure 3 and Figure 4 In the present embodiment, a power transmission unit 21 and a wiring 22 constitute a power transmission side resonance circuit 20. Figure 5 In the example, a plurality of power transmission-side resonant circuits 20 are connected to one power supply unit 10 .

[0045] like Figure 5 As shown in FIG. 1 , each wiring 22 includes two parts, a first wiring part 22a and a second wiring part 22b. The first wiring part 22a of each wiring 22 is connected to the corresponding power transmission unit 21 and the first connector 26. A plurality of first wiring parts 22a (in the case of a plurality of adjacently arranged power transmission units 21) connected to one first connector 26 are connected. Figure 5 In the example shown, there are four first wiring portions 22a. Therefore, one first connector 26 is connected to a plurality of adjacently arranged power transmission units 21. In addition, in the present embodiment, all first wiring portions 22a have the same length. Therefore, for the first wiring portions 22a, there is no difference in the magnitude of the parasitic inductance between the power transmission side resonance circuits 20.

[0046] The second wiring portion 22b of each wiring 22 is connected to the corresponding second connector 27 and the power supply unit 10. A group of a plurality of second wiring portions 22b (in Figure 5 In the example shown, there are four second wiring portions 22b). In particular, the second connector 27 is connected to the same number of second wiring portions 22b as the first wiring portions 22a connected to the first connector 26. The second connector 27 is connected to the first connector 26, whereby the second wiring portions 22b are connected to the corresponding first wiring portions 22a. In this embodiment, a plurality of second wiring portions 22b having the same length are connected to the first wiring portion 22a via the same first connector 26 and the same second connector 27. In addition, since the first connector 26 is connected to a plurality of first wiring portions 22a connected to a plurality of power transmission units 21 arranged adjacently, Figure 5In the example shown, the wiring of multiple power transmission side resonant circuits 20 (specifically, the power transmission side resonant circuit 20 including four power transmission units 21 on the right, the power transmission side resonant circuit 20 including four power transmission units 21 in the center, and the power transmission side resonant circuit 20 including four power transmission units 21 on the left) including multiple power transmission units 21 (power transmission side coils 23) arranged adjacent to each other has the same length.

[0047] In addition, in the present embodiment, a resonance compensation capacitor 25 is provided in the second wiring portion 22b. In particular, the resonance compensation capacitor 25 is connected in series with the second wiring portion 22b in the middle of the second wiring portion 22b. In addition, in the present embodiment, the resonance compensation capacitor 25 is also connected to one of the two wires of each second wiring portion 22b. In addition, in the present embodiment, the resonance compensation capacitor 25 provided in each second wiring portion 22b also has a capacitance corresponding to the length of the second wiring portion 22b. Therefore, in the present embodiment, the resonance compensation capacitors 25 provided in each group of multiple second wiring portions 22b having the same length and connected to the same second connector 27 have the same capacitance. Here, the wiring 22 of the power transmission side resonance circuit 20 including the second wiring portion 22b having the same length all have the same length, and therefore have the same parasitic inductance. Therefore, since the resonance compensation capacitors 25 provided in the second wiring portion 22b have the same capacitance as described above, the resonance frequencies of these power transmission side resonance circuits 20 can be made the same frequency.

[0048] According to the present embodiment, the first wiring portions 22a have the same length. Therefore, one first connector 26 and the plurality of first wiring portions 22a connected thereto have the same structure. Therefore, components can be shared when manufacturing the first connector 26 and the first wiring portion 22a. In addition, the second wiring portion 22b connected to one second connector 27 has the same structure. Therefore, the number of changes in the length of the second wiring portion 22b and the number of changes in the resonance compensation capacitor 25 can be reduced for the number of power transmission units 21, thereby reducing the manufacturing cost and making it easy to lay the ground power supply device 1. In addition, regardless of whether the power transmission units 21 are arranged at different positions, the first wiring portions 22a connected to the plurality of power transmission units 21 are connected to the second wiring portion 22b at the same location through the first connector 26 and the second connector 27, thereby making it easy to arrange the wiring.

[0049] On the other hand, in the present embodiment, the resonance compensation capacitor 25 is not provided in the first wiring portion 22a. Therefore, in the present embodiment, the capacitance of the resonance compensation capacitor 25 provided in the second wiring portion 22b is set in consideration of the length of the wiring 22 including the first wiring portion 22a and the second wiring portion 22b. In addition, in the present embodiment, since the length of the first wiring portion 22a is the same in all the power transmission side resonance circuits 20, the capacitance of the resonance compensation capacitor 25 provided in the second wiring portion 22b and the capacitance of the power transmission side capacitor 24 of the power transmission unit 21 can be set in consideration of the parasitic inductance generated in the first wiring portion 22a. In this way, by not having the resonance compensation capacitor 25 in the first wiring portion 22a, the first wiring portion 22a can be simply configured.

[0050] In the above embodiment, four wiring portions 22a and 22b are connected to one connector 26 and 27. However, it is sufficient to connect multiple wiring portions 22a and 22b to one connector 26 and 27, and wiring portions 22a and 22b other than four may be connected to one connector 26 and 27. Therefore, a group of second wiring portions 22b having the same length may include a plurality of second wiring portions 22b other than four.

[0051] In addition, a resonance compensation capacitor may be provided in the first wiring portion 22a. In this case, since the lengths of all the first wiring portions 22a are equal, the capacitances of the resonance compensation capacitors provided in all the first wiring portions 22a are also equal. In addition, the first wiring portion 22a has a capacitance corresponding to the length of the first wiring portion 22a to eliminate the influence of the parasitic inductance parasitic in the first wiring portion 22a on the resonance frequency of the power transmission unit 21.

[0052] Third embodiment Next, refer to Figure 6 , a ground power supply device 1 according to a third embodiment is described. The configuration of the ground power supply device 1 according to the third embodiment is basically the same as that of the ground power supply device 1 according to the second embodiment. Therefore, the following description will focus on the parts that are different from the configuration of the ground power supply device according to the second embodiment.

[0053] Figure 6 The structure of the ground power supply device 1 according to the third embodiment is schematically shown. Figures 3 to 5 The same picture. Figure 6As shown, in this embodiment, each wiring 22 also has a first wiring portion 22a and a second wiring portion 22c. The first wiring portion 22a of each wiring 22 is connected to the corresponding power transmission unit 21 and the switching switch 28. One switching switch 28 is connected to a plurality of first wiring portions 22a connected to a plurality of power transmission units 21 arranged adjacently. In addition, in this embodiment, all first wiring portions 22a also have the same length.

[0054] On the other hand, in the present embodiment, one second wiring portion 22c is connected to one switching switch 28. Therefore, one second wiring portion 22c is connected to a plurality of first wiring portions 22a via the switching switch 28. The plurality of second wiring portions 22c are connected to different switching switches 28 and a common power supply unit 10, respectively. In the present embodiment, a plurality of power transmission side resonance circuits 20 share one second wiring portion 22c. In either case, in the present embodiment, one power transmission unit 21 and one wiring 22 constitute one power transmission side resonance circuit 20.

[0055] In addition, in the present embodiment, the resonance compensation capacitor 25 is also provided in the second wiring portion 22c. In the present embodiment, the resonance compensation capacitor 25 provided in each second wiring portion 22c also has a capacitance corresponding to the length of the second wiring portion 22c.

[0056] Each switching switch 28 is connected to a plurality of power transmission units 21 via a plurality of first wiring portions 22a, and is connected to the power supply unit 10 via a second wiring portion 22c. The switching switch 28 selectively connects one of the plurality of first wiring portions 22a connected to the switching switch 28 to the second wiring portion 22c. Therefore, the switching switch 28 selectively connects one of the plurality of power transmission units 21 to the power supply unit 10. In other words, the switching switch 28 switches the power transmission unit 21 connected to the power supply unit 10.

[0057] The switching switch 28 is connected to the controller 30 and controlled by the controller 30. For example, the controller 30 identifies the power transmission unit 21 on which the vehicle 5 having the power receiving device 50 is traveling based on the output from any sensor (not shown), and switches the switching switch 28 so that the identified power transmission unit 21 and the power supply unit 10 are connected.

[0058] According to the present embodiment, one second wiring portion 22c is connected to a plurality of power transmission units 21. That is, one second wiring portion 22c is shared by a plurality of power transmission-side resonance circuits 20. Thus, the second wiring portion 22c can be easily laid. Furthermore, the number of converters 12 required in the power supply unit 10 can be reduced, thereby reducing the manufacturing cost of the power supply unit 10.

[0059] Fourth embodiment Next, refer to Figure 7 and Figure 8 , a ground power supply device 1 according to a fourth embodiment is described. The configuration of the ground power supply device 1 according to the fourth embodiment is basically the same as that of the ground power supply device 1 according to the first embodiment. Therefore, the following description will focus on the parts that are different from the configuration of the ground power supply device 1 according to the first embodiment.

[0060] In the ground power supply device 1 according to the first embodiment, each power transmission unit 21 and the power supply unit 10 are connected by a single wiring 22 of different lengths. In contrast, in the ground power supply device 1 according to this embodiment, each power transmission unit 21 and the power supply unit 10 are connected by a plurality of wiring modules 29 connected in series.

[0061] Figure 7 2 is a diagram schematically showing the structure of each wiring module 29. Figure 7 As shown, each wiring module 29 includes a cable 35 , a resonance compensation capacitor 25 connected in series with the cable 35 , and a connector 36 .

[0062] like Figure 7 As shown, each wiring module 29 has two cables 35 in which current flows in opposite directions. In addition, in the present embodiment, each wiring module 29 has one resonance compensation capacitor 25, and the resonance compensation capacitor 25 is connected to one of the two cables 35. In addition, both ends of the two cables 35 are connected to connectors 36, respectively. The connector 36 of each wiring module 29 can be connected to the connector 36 of other wiring modules 29. In addition, each wiring module 29 can also have a plurality of resonance compensation capacitors 25. In this case, more than one resonance compensation capacitor 25 is connected to each cable 35.

[0063] In the present embodiment, all the wiring modules 29 are configured so that the cables 35 have the same length and the resonance compensation capacitors 25 have the same capacitance. In particular, in the present embodiment, the lengths of the cables 35 of all the wiring modules 29 are equal to the intervals between the adjacently arranged power transmission units 21 (particularly the intervals between the adjacently arranged power transmission side coils 23). In addition, the capacitance of the resonance compensation capacitors 25 eliminates the influence of the parasitic inductance parasitic in the cables 35 constituting each wiring module 29 on the resonance frequency of the power transmission unit 21 (i.e., the resonance frequency generated in the power transmission side coil 23).

[0064] Figure 8 Schematically shows the structure of the ground power supply device 1 according to the fourth embodiment. Figure 8As shown, each wiring 22 connects one power transmission unit 21 and the power supply unit 10. The wirings 22 have different lengths from each other. In addition, in the present embodiment, each wiring 22 is formed by connecting a plurality of wiring modules 29 in series. As described above, since the cables 35 of all wiring modules 29 have the same length, the length of the wiring 22 is different depending on the number of wiring modules 29 constituting the wiring 22. Therefore, the farther the power transmission unit 21 is from the power supply unit 10, the more wiring modules 29 are used to form the wiring 22.

[0065] According to the present embodiment, all the wirings 22 are formed by a plurality of wiring modules 29 having the same configuration. Therefore, for each of the wirings 22 having different lengths, it is not necessary to use a wiring having a separate configuration with a resonance compensation capacitor having a different capacitance. Therefore, it is easy to manufacture the wirings 22, and it is easy to lay out the wirings 22 when laying out the power transmission side resonance circuit 20.

[0066] Furthermore, in the above-described embodiment, all the wirings 22 to which the power supply unit 10 is connected have different lengths from each other. Figure 4 As in the example shown, some of the wirings 22 have the same length as each other. In this case, the wirings 22 having the same length are formed by connecting the same number of wiring modules 29 in series.

[0067] In addition, in the above-mentioned embodiment, the wiring 22 extending from the power supply unit 10 to the power transmission unit 21 is entirely formed by the wiring module 29. However, only a portion of each wiring 22 may be formed by the wiring module 29. For example, in the above-mentioned second and third embodiments, only the second wiring portions 22b and 22c are formed by connecting the wiring modules 29 in series, and the first wiring portion 22a is formed without using the wiring module 29. In addition, in the case where only the second wiring portions 22b and 22c are constituted by the wiring modules 29 like this, the length of the cable 35 of all the wiring modules 29 becomes an integer multiple of at least twice the interval between the adjacently arranged power transmission units 21 (especially the interval between the adjacently arranged power transmission side coils 23). In particular, in Figure 5 and Figure 6 In the example shown, since four power transmission units 21 are integrated, the length of the cables 35 of all wiring modules 29 is four times the distance between the power transmission units 21 arranged adjacently.

[0068] In all the above-mentioned embodiments, the ground power supply device 1 supplies power to the moving vehicle 5 in a non-contact manner. However, the ground power supply device 1 may also supply power to a non-moving vehicle 5 such as a stopped vehicle 5 in a non-contact manner. Specifically, the ground power supply device 1 is provided in a parking lot having a plurality of parking sections, and the power transmission unit 21 is provided in each of the plurality of parking sections.

[0069] As mentioned above, although the preferred embodiment concerning this invention was described, this invention is not limited to these embodiments, Various corrections and changes can be implemented within the description of the scope of claims. [Explanation of symbols]

[0070] 1 Ground power supply device 5. Vehicles 10 Power supply unit 20 Transmission side resonance circuit 21 Power transmission unit 22 Wiring 25 Resonance compensation capacitor 30 Controllers.

Claims

1. A ground power supply device that transmits power to a vehicle without contact, The ground power supply device comprises: a plurality of resonant circuits; and a power supply source for supplying AC power having the same frequency to all the resonant circuits. Each resonant circuit includes: a coil buried in the road and used for contactless power transmission; and wiring connecting each coil and the power supply source. The wiring of each resonant circuit is formed to have a length at least partially different from that of the wiring of the other resonant circuits, and the inductance parasitic in the wiring due to the difference in length is at least partially different from that of the wiring of the other resonant circuits, The resonant circuits further include capacitors having different capacitances so that the resonant frequencies of all the resonant circuits are the same even if the parasitic inductances in the wirings are different.

2. The ground power supply device according to claim 1, wherein: The capacitor has such a capacitance that even if the parasitic inductance in the wiring is different, the resonance frequency of all the resonance circuits becomes the same as the frequency of the AC power.

3. The ground power supply device according to claim 1 or 2, wherein: The wirings of the plurality of resonant circuits including the plurality of coils arranged adjacent to each other have the same length.

4. The ground power supply device according to claim 1 or 2, wherein: The wiring has: a first portion having the same length in all the resonant circuits; and a second portion having partially different lengths between the resonant circuits, The second portion is provided with the capacitor.

5. The ground power supply device according to claim 4, wherein: The capacitors provided in the plurality of second portions having the same length have the same capacitance.

6. The ground power supply device according to claim 4, wherein: The first portion has no capacitor.

7. The ground power supply device according to claim 4, wherein: The first portion is connected to the coil, the second portion is connected to the power supply source, and a plurality of the second portions having the same length are connected to the first portion via a same connector.

8. The ground power supply device according to claim 1 or 2, wherein: The wiring is at least partially formed by connecting a plurality of wiring modules in series, each of the plurality of wiring modules having a cable having the same length and a capacitor connected to the cable, The capacitor of each wiring module has a capacitance that cancels the influence of the parasitic inductance of the cable of the wiring module on the resonant frequency generated in the coil at the frequency of the AC power. The resonance circuit having wirings of different lengths has the wirings of different lengths because the number of wiring blocks constituting the resonance circuit is different.

9. The ground power supply device according to claim 8, wherein: The length of the cable of the wiring module is equal to an integral multiple of the interval between adjacent coils.

10. A wiring for a resonance circuit of a ground power supply device, the ground power supply device comprising a plurality of resonance circuits and a power supply source for supplying AC power having the same frequency to all the resonance circuits, and transmitting power to a vehicle in a contactless manner. The wiring of each resonant circuit connects each coil of the resonant circuit to the power supply source, and the coil is buried in the road and is used to transmit power in a contactless manner. The wiring of each resonant circuit is formed to have a length at least partially different from that of the wiring of the other resonant circuits, and the inductance parasitic in the wiring due to the difference in length is at least partially different from that of the wiring of the other resonant circuits, Each wiring has a capacitor with a different capacitance so that the resonance frequency of all the resonance circuits is the same even if the parasitic inductance in the wiring is different.

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