Power transmission equipment and contactless power supply system

Abstract

To provide a power transmission device and a non-contact power supply system that can increase the degree of freedom in layout of a high-frequency power supply and a power transmission unit.SOLUTION: A power transmission device 10 includes: a high-frequency power supply 11; a plurality of power transmission units 17a to 17c; a distribution circuit 12; and transmission lines 16a to 16c. Each of the power transmission units 17a to 17c transmits electric power to power reception units 21a to 21c by forming a wireless coupler with any one of the power reception units 21a to 21c provided in an electrically-driven mobility 2. The distribution circuit 12 distributes high-frequency power output from the high-frequency power supply 11 to each of the plurality of power transmission units 17a to 17c. Each of the transmission lines 16a to 16c transmits the power distributed from the distribution circuit 12 to the corresponding power transmission units 17a to 17c.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a power transmission device that transmits power in a non-contact manner to a power receiving device having a power receiving unit for receiving power to supply power to a load, and a non-contact power supply system equipped with the power transmission device. [Background technology]

[0002] In recent years, electric vehicles and autonomous, unmanned electric mobility have attracted attention, and various research and development efforts are underway. However, challenges remain in promoting the widespread adoption of such electric vehicles and electric mobility, including the cost and weight of batteries, the length of charging time, the difficulty of recycling, and increased labor costs. One method being explored to address these challenges is the development of unmanned and contactless (wireless) power supply technology.

[0003] Examples of such non-contact power supply methods include magnetic field coupling and electric field coupling. In the magnetic field coupling method, power is transmitted non-contact by the coupling of a magnetic field formed between a transmitting coil and a receiving coil, which transmits power as magnetic field energy through space (see, for example, Patent Document 1). In the electric field coupling method, power is transmitted non-contact by the coupling of a magnetic field formed between a transmitting electrode and a receiving electrode, which transmits power as electric field energy through space (see, for example, Patent Document 2). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Patent No. 5624109 [Patent Document 2] Patent No. 6761962 [Overview of the project] [Problems that the invention aims to solve]

[0005] Incidentally, when it comes to providing contactless power to mobile devices such as electric vehicles and electric mobility devices, there are two possible states: stationary power supply, where power is supplied to a mobile device that is stopped at a power supply spot, and on-road power supply, where power is supplied to a mobile device that is in operation (driving).

[0006] In contactless power supply systems, it is common to place a high-frequency power supply near the power transmission unit (transmission coil or transmission electrode) that transmits power without contact. However, when it is necessary to simultaneously supply power to multiple moving objects while they are stationary, it is necessary to set up multiple power supply spots, and a lot of space is required for the installation of the high-frequency power supply at each power supply spot. As a result, for example, when supplying power to multiple electric mobility devices while they are stationary in a factory, the installation of the high-frequency power supply has the problem of encroaching on workspace. Similarly, when supplying power to electric vehicles parked in a parking lot, the installation of the high-frequency power supply has the problem of encroaching on parking space or reducing the number of vehicles that can be parked.

[0007] Furthermore, in the case of power supply while the vehicle is in motion, the power transmission section must be buried along a predetermined route. However, in this case, depending on the location of the high-frequency power supply, there was a problem in that the power transmission section had to be buried in places where the moving vehicle did not pass, or where it passed through only a small percentage of the route.

[0008] The present invention was made to solve the above-mentioned problems and aims to provide a power transmission device and a contactless power supply system that can improve the degree of freedom in the layout between the high-frequency power supply and the power transmission unit. [Means for solving the problem]

[0009] To achieve this objective, a power transmission device according to a first aspect of the present invention has a power receiving unit for receiving power to be supplied to a load provided on a mobile body, and transmits power to the power receiving unit provided on the mobile body in a non-contact manner, comprising: a high-frequency power supply; a plurality of power transmission units that transmit power to the power receiving unit by forming a wireless coupler with the power receiving unit, each not simultaneously transmitting power to the same power receiving unit; a distribution circuit for distributing the high-frequency power output from the high-frequency power supply to each of the plurality of power transmission units; and a transmission line provided corresponding to each of the plurality of power transmission units for transmitting the power distributed by the distribution circuit to the corresponding power transmission unit.

[0010] A power transmission device according to a second aspect of the present invention is a power transmission device according to a first aspect, which includes a compensation circuit that compensates for the deviation in reactance corresponding to each of the plurality of power transmission units.

[0011] A power transmission device according to a third aspect of the present invention, in which the power transmission device according to the second aspect comprises a compensation circuit for a transmission line that compensates for a deviation in reactance in the transmission line connected to the corresponding power transmission unit, and a compensation circuit for a coupler that compensates for a deviation in reactance in the wireless coupler that can be formed by the corresponding power transmission unit, wherein at least the compensation circuit for the transmission line is provided in the same housing as the distribution circuit.

[0012] A power transmission device according to a fourth aspect of the present invention, in which the power transmission device according to a third aspect, compensates for the deviation of reactance in the wireless coupler by comprising a primary side compensation circuit for the coupler provided on the power transmission side and a secondary side compensation circuit for the coupler provided on the power receiving side, wherein the primary side compensation circuit for the coupler is located on the high-frequency power supply side of the transmission line compensation circuit and is provided in the same housing as the distribution circuit.

[0013] A power transmission device according to a fifth aspect of the present invention is a power transmission device according to a third or fourth aspect, wherein the transmission line compensation circuit is configured such that the characteristics of a transformer or gyrator are obtained by the transmission line and the transmission line compensation circuit, and the coupler compensation circuit is configured such that the characteristics of a transformer or gyrator are obtained by the wireless coupler and the coupler compensation circuit.

[0014] A power transmission device according to the sixth aspect of the present invention is a power transmission device according to any of the first to fifth aspects, wherein the transmission line is composed of a coaxial cable or a shielded cable.

[0015] A power transmission device according to a seventh aspect of the present invention is a power transmission device according to any of the first to sixth aspects, wherein the distribution circuit is equipped with a switch for transmitting power to the corresponding transmission line and for stopping the power transmission, corresponding to each of the transmission lines connected to each of the plurality of power transmission units, and the power transmission device is equipped with a control unit that controls each switch based on whether or not to transmit power by the corresponding power transmission unit.

[0016] The eighth aspect of the present invention is a power transmission device in which, in any of the first to seventh aspects, the high-frequency power supply and the distribution circuit are provided in the same housing.

[0017] A non-contact power supply system according to the ninth aspect of the present invention comprises a power receiving device having a power receiving unit for receiving power to be supplied to a load, and a power transmitting device according to any of the first to eighth aspects. [Effects of the Invention]

[0018] According to the first aspect of the present invention, high-frequency power is supplied from a high-frequency power source to a power transmission unit that forms a wireless coupler with a power receiving unit of a power receiving device provided on a mobile body, and power is transmitted non-contact from the power transmission unit to the power receiving unit that forms the wireless coupler. The power received by the power receiving unit is supplied to a load provided on the mobile body. Here, the power transmission device has a plurality of power transmission units, each of which does not simultaneously transmit the power to the same power receiving device. The high-frequency power output from the high-frequency power source is distributed to each of the plurality of power transmission units by a distribution circuit. The distributed power is then transmitted to the corresponding power transmission unit by each transmission line provided corresponding to each of the plurality of power transmission units. In this way, by providing a distribution circuit, power can be distributed from one high-frequency power source to multiple power transmission units. Furthermore, even if the distance between the high-frequency power source and each power transmission unit is large, or if the distance is staggered, the power distributed by the distribution circuit can be transmitted by the transmission line corresponding to each power transmission unit. Therefore, there is an effect of improving the flexibility of the layout between the high-frequency power source and the power transmission units.

[0019] The power transmission device according to the second aspect of the present invention provides the following effects in addition to those of the power transmission device according to the first aspect. Specifically, the difference in reactance in each power transmission unit is compensated by a compensation circuit provided corresponding to each of the multiple power transmission units. As a result, even if each power transmission unit is configured in a shape suited to its respective circumstances and installed in a position suited to its respective circumstances, the compensation circuit makes the imaginary part of the input impedance viewed from the high-frequency power supply to the load side approximately zero, enabling stable contactless power supply. Therefore, there is an effect of improving the degree of freedom in the layout between the high-frequency power supply and the power transmission unit.

[0020] According to the power transmission device according to the third aspect of the present invention, in addition to the effects achieved by the power transmission device according to the second aspect, the following effects are achieved. The compensation circuit has a transmission line compensation circuit and a coupler compensation circuit. The transmission line compensation circuit compensates for the reactance deviation in the transmission line connected to the corresponding power transmission unit, and the coupler compensation circuit compensates for the reactance deviation in the wireless coupler that can be formed by the corresponding power transmission unit. As a result, there is an effect that the compensation circuit provided corresponding to each power transmission unit can be easily designed by dividing it into a transmission line compensation circuit and a coupler compensation circuit. Further, since at least the transmission line compensation circuit is provided in the same housing as the distribution circuit, the degree of freedom in the layout of the high-frequency power supply and the power transmission unit can be improved, and there is an effect that the space saving of the power transmission device in the area where the power transmission device is provided can be achieved.

[0021] According to the power transmission device according to the fourth aspect of the present invention, in addition to the effects achieved by the power transmission device according to the third aspect, the following effects are achieved. That is, the coupler compensation circuit is configured to compensate for the reactance deviation in the wireless coupler by a coupler primary-side compensation circuit provided on the power transmission unit side and a coupler secondary-side compensation circuit provided on the power reception unit side. The coupler primary-side compensation circuit is arranged on the high-frequency power supply side of the transmission line compensation circuit and is provided in the same housing as the distribution circuit together with the transmission line compensation circuit. As a result, there is an effect that the degree of freedom in the layout of the high-frequency power supply and the power transmission unit can be further improved, and the space saving of the power transmission device in the area where the power transmission device is provided can be further achieved.

[0022] According to the power transmission device according to the fifth aspect of the present invention, in addition to the effects achieved by the power transmission device according to the third or fourth aspect, the following effects are achieved. That is, the transmission line compensation circuit is configured by the transmission line and the transmission line compensation circuit so as to have the characteristics of a transformer or a gyrator, and the coupler compensation circuit is configured by the wireless coupler and the coupler compensation circuit so as to have the characteristics of a transformer or a gyrator. Here, when a transformer or a gyrator is provided in the front stage and a transformer or a gyrator is also provided in the rear stage and these are connected in cascade, the characteristics of one transformer or gyrator are obtained. Therefore, by configuring the transmission line compensation and the coupler compensation circuit as described above, when looking at the loads to be powered from the high-frequency power supply, it can be regarded that the loads are connected via one transformer or gyrator. Therefore, the imaginary part of the input impedance when looking at each load from the high-frequency power supply becomes substantially zero, so that power can be stably and efficiently supplied from the high-frequency power supply to the loads. And by designing the transmission line compensation circuit so that the transmission line and the transmission line compensation circuit have the characteristics of a transformer or a gyrator, and designing the coupler compensation circuit so that the wireless coupler and the coupler compensation circuit have the characteristics of a transformer or a gyrator, there is an effect that a compensation circuit capable of stably and efficiently supplying power from the high-frequency power supply to the load can be easily realized.

[0023] According to the power transmission device according to the sixth aspect of the present invention, in addition to the effects achieved by the power transmission device according to any one of the first to fifth aspects, the following effects are achieved. That is, since the transmission line is constituted by a coaxial cable or a shielded cable, the transmission line can be easily made to crawl on a wall or the ground. Thereby, even if the installation position of the power transmission unit with respect to the high-frequency power supply is an arbitrary position, the distribution circuit and the power transmission unit can be easily connected by the transmission line constituted by the coaxial cable or the shielded cable. Therefore, there is an effect that the degree of freedom in the layout of the high-frequency power supply and the power transmission unit can be further increased.

[0024] The power transmission device according to the seventh aspect of the present invention provides the following effects in addition to the effects of the power transmission device according to any of the first to sixth aspects. Specifically, the distribution circuit is provided with switches corresponding to each transmission line connected to each of the multiple power transmission units, for transmitting power to the corresponding transmission line and stopping the power transmission, and each switch is controlled by the control unit based on whether or not the corresponding power transmission unit transmits power. As a result, by controlling the switches to stop power transmission to transmission lines connected to power transmission units that do not transmit power (for example, those not configured with wireless couplers), it is possible to suppress the supply of power to power transmission units in such a state. Therefore, it is possible to suppress the wasteful consumption of power and to suppress the leakage of unnecessary electromagnetic waves from the power transmission units. Consequently, it is possible to save energy and ensure safety.

[0025] The power transmission device according to the eighth aspect of the present invention provides the following effects in addition to the effects of the power transmission device according to any of the first to seventh aspects. Specifically, since the high-frequency power supply and the distribution circuit are provided in the same housing, the degree of freedom in the layout of the high-frequency power supply and the power transmission unit can be further improved, and the space required for the power transmission device in the area where it is installed can be further reduced.

[0026] According to the non-contact power supply system of the ninth aspect of the present invention, a power transmission device according to any of the first to eighth aspects is provided, and the power transmitted from the power transmission unit of the power transmission device is received non-contact by a power receiving device provided on a mobile body. The power received by the power receiving device is then supplied to a load provided on the mobile body. This makes it possible to achieve the same effect as the corresponding power transmission device. [Brief explanation of the drawing]

[0027] [Figure 1] This is a schematic diagram showing the general configuration of a power transmission device and a contactless power supply system according to one embodiment of the present invention. [Figure 2]This is a schematic circuit diagram showing an example of the circuit configuration of the contactless power supply system. [Figure 3] This is a schematic circuit diagram illustrating another example of the circuit configuration of the same contactless power supply system. [Figure 4] (a) is a diagram illustrating the compensation circuit for the transmission line and the compensation circuit for the coupler provided in the contactless power supply system, and (b) is a diagram illustrating the characteristics of the transformer and gyrator. [Figure 5] This diagram shows the characteristics when two transformers are connected in cascaded order, when two gyrators are connected in cascaded order, when a transformer and a gyrator are connected in cascaded order, and when a gyrator and a transformer are connected in cascaded order. [Figure 6] When a transmission line, a compensation circuit for the transmission line, a wireless coupler, and a compensation circuit for the coupler are considered as a single transformer, (a) is a circuit diagram showing an example of a distribution circuit when the high-frequency power supply is a constant voltage source, and (b) is a circuit diagram showing an example of a distribution circuit when the high-frequency power supply is a constant current source. [Figure 7] When a transmission line, a compensation circuit for the transmission line, a wireless coupler, and a compensation circuit for the coupler are considered as a single gyrator, (a) is a circuit diagram showing an example of a distribution circuit when the high-frequency power supply is a constant voltage source, and (b) is a circuit diagram showing an example of a distribution circuit when the high-frequency power supply is a constant current source. [Figure 8] (a) is a circuit diagram showing the configuration of the transmission line compensation circuit when it is implemented as a T-type circuit, (b) is a circuit diagram showing the configuration of the transmission line compensation circuit when it is implemented as a π-type circuit, and (c) is a diagram showing the calculation formulas for the reactance of each element when the transmission line compensation circuit is configured as a T-type circuit and as a π-type circuit, respectively, for the case where the circuit characteristics of the combination of the transmission line compensation circuit and the transmission line are as a transformer and as a gyrator. [Figure 9]This figure shows the possible connection methods for the coupler compensation circuit when the wireless coupler is configured using an electric field coupling method, the topology of the coupler compensation circuit and wireless coupler for each connection method, the formulas for calculating the reactance of the primary and secondary compensation circuits for the coupler for each connection method, and the formulas for calculating the circuit characteristics obtained from the coupler compensation circuit and wireless coupler and their transformation ratio or gyration resistance for each connection method. [Figure 10] This figure shows the possible connection methods for the coupler compensation circuit when the wireless coupler is configured using a magnetic field coupling method, the topology of the coupler compensation circuit and wireless coupler for each connection method, the formulas for calculating the reactance of the primary and secondary compensation circuits for the coupler for each connection method, and the formulas for calculating the circuit characteristics obtained from the coupler compensation circuit and wireless coupler and their transformation ratio or gyration resistance for each connection method. [Figure 11] (a) is a diagram showing the impedance transformation when an inductor or capacitor connected in series to the input side of a wireless coupler as a primary side compensation circuit for the coupler is moved to the high-frequency power supply side beyond the transmission line compensation circuit which constitutes a transformer together with the transmission line, and (b) is a diagram showing the impedance transformation when an inductor or capacitor connected in parallel to the input side of a wireless coupler as a primary side compensation circuit for the coupler is moved to the high-frequency power supply side beyond the transmission line compensation circuit which constitutes a transformer together with the transmission line. [Figure 12] (a) is a diagram showing the impedance transformation when an inductor or capacitor connected in series to the input side of a wireless coupler as a primary side compensation circuit for the coupler is moved to the high-frequency power supply side than the transmission line compensation circuit which forms a gyrator together with the transmission line, and (b) is a diagram showing the impedance transformation when an inductor or capacitor connected in parallel to the input side of a wireless coupler as a primary side compensation circuit for the coupler is moved to the high-frequency power supply side than the transmission line compensation circuit which forms a gyrator together with the transmission line. [Figure 13](a) is a diagram showing an example of the equivalent circuit of the designed contactless power supply system, and (b) is a diagram showing the values ​​of each parameter of the designed equivalent circuit. [Figure 14] This figure shows the simulation results of the equivalent circuit. [Figure 15] (a) is a diagram showing another example of the equivalent circuit of the designed contactless power supply system, and (b) is a diagram showing the values ​​of each parameter of the same designed equivalent circuit. [Figure 16] This figure shows the simulation results of the equivalent circuit. [Figure 17] This diagram shows yet another example of the equivalent circuit of the contactless power supply system we designed. [Figure 18] This diagram shows the values ​​of each parameter in the designed equivalent circuit. [Figure 19] This figure shows the simulation results of the equivalent circuit. [Modes for carrying out the invention]

[0028] Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings. The embodiments described below are all preferred specific examples of the present invention. Therefore, the numerical values, shapes, materials, components, and their arrangement and connection configurations shown in the following embodiments are examples only and are not intended to limit the present invention. Accordingly, among the components in the following embodiments, those not described in the independent claims representing the highest-level concept of the present invention will be described as optional components. Furthermore, in each figure, substantially identical components are denoted by the same reference numerals, and redundant explanations are omitted or simplified.

[0029] First, with reference to Figures 1 to 3, the outline of the power transmission device 10 and contactless power supply system 1 according to one embodiment of the present invention will be described. Figure 1 is a schematic configuration diagram showing the general configuration of the power transmission device 10 and contactless power supply system 1. Figure 2 is a schematic circuit diagram showing an example of the circuit configuration of the contactless power supply system 1. Figure 3 is a schematic circuit diagram showing another example of the circuit configuration of the contactless power supply system 1.

[0030] The contactless power supply system 1 is a system that supplies power to a load attached to a moving object wirelessly (without contact). For example, as shown in Figure 1, the contactless power supply system 1 is installed in a factory where multiple electric mobility devices 2 operate automatically and unmanned as moving objects.

[0031] Examples of electric mobility include automated guided vehicles (AGVs) and automated mobile robots (AMRs). AGVs automatically navigate according to guides such as magnetic tape, beacons, and barcodes based on pre-programmed software. Automated mobile robots (AMRs) automatically navigate without guidance by controlling acceleration, deceleration, and steering while judging the surrounding conditions obtained from map information, current location information, and sensing.

[0032] The electric mobility device 2 is equipped with a battery (not shown) that stores the power necessary for its operation. The contactless power supply system 1 uses this battery as a load and supplies power to the battery in a contactless manner. The battery stores power by being charged by the power supplied by the contactless power supply system 1.

[0033] Furthermore, the mobile object to which power is supplied by the contactless power supply system 1 is not limited to the electric mobility device 2 described above, but may also be, for example, an electric vehicle traveling on a public (or private) road, an electric kick scooter, or a personal mobility device that is a single-person mobility assistance device. Also, the load to which power is supplied by the contactless power supply system 1 is not limited to a battery, but may also be something that operates using the supplied power (for example, a motor).

[0034] The following explanation will continue using the example of contactless power supply system 1 supplying power to the battery of electric mobility 2 traveling within a factory. When contactless power supply system 1 supplies power to a load on another mobile object, the explanation can be explained by replacing "within the factory" with the location where that mobile object travels.

[0035] The contactless power supply system 1 consists of a power transmission device 10 fixedly installed within the factory and power receiving devices (at least one of the first power receiving device 20a, the second power receiving device 20b, and the third power receiving device 20c shown in Figures 2 and 3) provided on each electric mobility device 2.

[0036] First, let's explain the power receiving devices (first power receiving device 20a, second power receiving device 20b, and third power receiving device 20c). The first power receiving device 20a, the second power receiving device 20b, and the third power receiving device 20c are each installed on separate electric mobility devices 2, and all of them are devices that receive power wirelessly (contactless) to supply power to a battery (receiving-side load) installed on the same electric mobility device 2.

[0037] As shown in Figures 2 and 3, the first power receiving device 20a is configured to include at least a first power receiving section 21a and a secondary side compensation circuit 142a for the first coupler. The other power receiving devices (second power receiving device 20b, third power receiving device 20c) have a similar configuration.

[0038] Specifically, the second power receiving device 20b is configured to have at least a second power receiving section 21b and a secondary compensation circuit 142b for the second coupler, and the third power receiving device 20c is configured to have at least a third power receiving section 21c and a secondary compensation circuit 142c for the third coupler. The second power receiving section 21b and the third power receiving section 21c have the same configuration as the first power receiving section 21a, and the secondary compensation circuit 142b for the second coupler and the secondary compensation circuit 142c for the third coupler have the same configuration as the secondary compensation circuit 142a for the first coupler.

[0039] Therefore, the following explanation will focus on the first power receiving device 20a (first power receiving section 21a and secondary compensation circuit 142a for the first coupler), and detailed explanations of the second power receiving device 20b (second power receiving section 21b and secondary compensation circuit 142b for the second coupler) and the third power receiving device 20c (third power receiving section 21c and secondary compensation circuit 142c for the third coupler) will be omitted.

[0040] In the following explanation, the first power receiving section 21a, the second power receiving section 21b, and the third power receiving section 21c will be collectively referred to as the "power receiving section." Furthermore, the second-side compensation circuit 142a for the first coupler, the second-side compensation circuit 142b for the second coupler, and the second-side compensation circuit 142c for the third coupler will be collectively referred to as the "secondary compensation circuit for the coupler."

[0041] The first power receiving unit 21a forms a wireless coupler (first wireless coupler 30a in the example shown in Figures 2 and 3) with one of the first power transmission unit 17a, second power transmission unit 17b, and third power transmission unit 17c of the power transmission device 10 (first power transmission unit 17a in the example shown in Figures 2 and 3).

[0042] When the first power receiving unit 21a forms a first wireless coupler 30a with the first power transmitting unit 17a, it receives power transmitted from the first power transmitting unit 17a wirelessly. When the first power receiving unit 21a forms a second wireless coupler 30b with the second power transmitting unit 17b, it receives power transmitted from the second power transmitting unit 17b wirelessly. When the first power receiving unit 21a forms a third wireless coupler 30c with the third power transmitting unit 17c, it receives power transmitted from the third power transmitting unit 17c wirelessly.

[0043] The wireless coupler may be based on, for example, an electric field coupling method or a magnetic field coupling method. In the case of the electric field coupling method, the first power receiving section 21a is composed of electrodes which are flat conductors. In the case of the magnetic field coupling method, the first power receiving section 21a is composed of a coil.

[0044] The secondary compensation circuit 142a for the first coupler is cascaded to the first power receiving unit 21a on the output side of the first power receiving unit 21a and, together with the primary compensation circuit for the coupler described later, is provided in the power transmission device 10 corresponding to the power transmission unit that forms a wireless coupler with the first power receiving unit 21a, and constitutes a coupler compensation circuit.

[0045] For example, when the first power receiving unit 21a forms a first wireless coupler 30a with the first power transmitting unit 17a, it forms a first coupler compensation circuit 14a together with the first coupler primary side compensation circuit 141a provided in the power transmission device 10 corresponding to the first power transmitting unit 17a. When the first power receiving unit 21a forms a second wireless coupler 30b with the second power transmitting unit 17b, it forms a second coupler compensation circuit 14b together with the second coupler primary side compensation circuit 141b provided in the power transmission device 10 corresponding to the second power transmitting unit 17b. When the first power receiving unit 21a forms a third wireless coupler 30c with the third power transmitting unit 17c, it forms a third coupler compensation circuit 14c together with the third coupler primary side compensation circuit 141c provided in the power transmission device 10 corresponding to the third power transmitting unit 17c.

[0046] Details of the secondary compensation circuit 142a for the first coupler will be described later, along with the explanations of the first coupler compensation circuit 14a, the second coupler compensation circuit 14b, and the third coupler compensation circuit 14c (hereinafter collectively referred to as the "coupler compensation circuit"). These coupler compensation circuits compensate for the reactance deviation in the corresponding wireless coupler.

[0047] The first power receiving device 20a converts the power received by the first power receiving unit 21a into a DC voltage via a rectifier circuit (not shown) and then supplies power to the battery. The battery stores the supplied power. The electric mobility device 2 uses the power stored in this battery to drive a motor, etc., and moves around the factory.

[0048] Next, the power transmission device 10 will be described. As shown in Figure 1, the power transmission device 10 consists of a power supply unit 5, a plurality of power transmission units (in the example shown in Figure 1, the first power transmission unit 17a, the second power transmission unit 17b, and the third power transmission unit 17c), and a plurality of transmission lines (in the example shown in Figure 1, the first transmission line 16a, the second transmission line 16b, and the third transmission line 16c).

[0049] The first power transmission unit 17a, the second power transmission unit 17b, and the third power transmission unit 17c are all fixed and embedded in the floor or walls of the factory, or installed on the floor. As shown in Figures 2 and 3, the first power transmission unit 17a, the second power transmission unit 17b, and the third power transmission unit 17c each form a wireless coupler with the power receiving unit of the power receiving device provided on each electric mobility device 2, thereby transmitting power to the power receiving unit wirelessly. Furthermore, the first power transmission unit 17a, the second power transmission unit 17b, and the third power transmission unit 17c are each configured to independently transmit power to the power receiving devices of different electric mobility devices 2. However, the first power transmission unit 17a, the second power transmission unit 17b, and the third power transmission unit 17c do not simultaneously transmit power to the same power receiving device.

[0050] Specifically, the first power transmission unit 17a can form a first wireless coupler 30a with any of the first power receiving unit 21a of the first power receiving device 20a shown in Figures 2 and 3, the second power receiving unit 21b of the second power receiving device 20b, and the third power receiving unit 21c of the third power receiving device 20c. Furthermore, the second power transmission unit 17b can form a second wireless coupler 30b with any of these power receiving units, and the third power transmission unit 17c can form a third wireless coupler 30c with any of these power receiving units.

[0051] The first power transmission unit 17a transmits power wirelessly to the power receiving unit forming the first wireless coupler 30a, the second power transmission unit 17b transmits power wirelessly to the power receiving unit forming the second wireless coupler 30b, and the third power transmission unit 17c transmits power wirelessly to the power receiving unit forming the third wireless coupler 30c.

[0052] In this case, if the wireless coupler uses an electric field coupling method, the first power transmission unit 17a, the second power transmission unit 17b, and the third power transmission unit 17c are composed of electrodes that are flat conductors. In this case, as described above, the receiving unit of each power receiving device is also composed of electrodes that are flat conductors. The first power transmission unit 17a, the second power transmission unit 17b, and the third power transmission unit 17c each form an electric field coupling by facing the receiving unit of the power receiving device, and transmit power to the opposing receiving unit.

[0053] Furthermore, if the wireless coupler uses a magnetic field coupling method, the first power transmission unit 17a, the second power transmission unit 17b, and the third power transmission unit 17c are composed of coils. In this case, as described above, the power receiving unit of each power receiving device is also composed of coils. The first power transmission unit 17a, the second power transmission unit 17b, and the third power transmission unit 17c each form a magnetic field coupling by approaching the power receiving unit of the power receiving device and transmit power to the approaching power receiving unit.

[0054] Here, the first power transmission unit 17a and the third power transmission unit 17c are embedded and fixed in the floor or wall at a location called a power supply spot. A power supply spot is a place where power is supplied to an electric mobility vehicle 2 that is stopped (or parked) at that location. In other words, the first power transmission unit 17a and the third power transmission unit 17c are power transmission units provided for providing power to an electric mobility vehicle 2 that is stopped at a power supply spot.

[0055] On the other hand, the second power transmission unit 17b is embedded and fixed in the floor or wall of the route (roadway) on which the electric mobility 2 can travel. In other words, the second power transmission unit 17b is a power transmission unit provided for power supply while the electric mobility 2 is in operation (traveling).

[0056] Thus, the contactless power supply system 1 is provided with a mixture of power transmission units (first power transmission unit 17a, third power transmission unit 17c) that supply power to the electric mobility 2 while it is stationary, and power transmission units (second power transmission unit 17b) that supply power while it is in motion. Alternatively, the contactless power supply system 1 may consist of multiple power transmission units that supply power to the electric mobility 2 while it is stationary, or multiple power transmission units that supply power to the electric mobility 2 while it is in motion.

[0057] The power supply unit 5 supplies power to the first power transmission unit 17a, the second power transmission unit 17b, and the third power transmission unit 17c, and is configured within a single enclosure that includes the high-frequency power supply 11, distribution circuit 12, and control unit 18 shown in Figure 1. The enclosure comprising the power supply unit 5 is fixedly installed within the factory.

[0058] The high-frequency power supply 11 is composed of a high-frequency inverter that generates high-frequency power from DC power or commercial power, and outputs the high-frequency power generated by the high-frequency inverter. The distribution circuit 12 is a circuit for distributing the high-frequency power output from the high-frequency power supply 11 to each of the multiple transmission units: the first transmission unit 17a, the second transmission unit 17b, and the third transmission unit 17c. The control unit 18 controls switches (first switch 13a, second switch 13b, and third switch 13c shown in Figures 2 and 3) provided in the distribution circuit 12, corresponding to each of the transmission lines (first transmission line 16a, second transmission line 16b, and third transmission line 16c) connected to each of the multiple transmission units, as described later. Details of the distribution circuit 12 and the control unit 18 will be described later with reference to Figures 2 and 3.

[0059] The transmission lines are provided in accordance with each of the multiple power transmission units and connect the distribution circuit 12 to the corresponding power transmission unit. Specifically, the first transmission line 16a is provided in accordance with the first power transmission unit 17a and transmits the power distributed to the first power transmission unit 17a by the distribution circuit 12 to the first power transmission unit 17a. The second transmission line 16b is provided in accordance with the second power transmission unit 17b and transmits the power distributed to the second power transmission unit 17b by the distribution circuit 12 to the second power transmission unit 17b. The third transmission line 16c is provided in accordance with the third power transmission unit 17c and transmits the power distributed to the third power transmission unit 17c by the distribution circuit 12 to the third power transmission unit 17c.

[0060] These transmission lines are all composed of coaxial cables or shielded cables.

[0061] Next, the details of the distribution circuit 12 will be explained with reference to Figures 2 and 3. In the example shown in Figure 2, the distribution circuit 12 is configured such that multiple power transmission units (first power transmission unit 17a, second power transmission unit 17b, and third power transmission unit 17c) are connected in parallel to one high-frequency power supply 11. In this case, by using a constant voltage source that always outputs a constant voltage as the high-frequency power supply 11, the voltage output from the high-frequency power supply 11 is applied to each of the power transmission units connected in parallel. As a result, the high-frequency power output from the high-frequency power supply 11 is distributed to each power transmission unit.

[0062] Furthermore, in the example shown in Figure 3, the distribution circuit 12 is configured such that multiple power transmission units (first power transmission unit 17a, second power transmission unit 17b, and third power transmission unit 17c) are connected in series to a single high-frequency power supply 11. In this case, by using a constant current source that always outputs a constant current as the high-frequency power supply 11, the current output from the high-frequency power supply 11 flows to each power transmission unit. As a result, the high-frequency power output from the high-frequency power supply 11 is distributed to each power transmission unit.

[0063] As shown in Figures 2 and 3, the distribution circuit 12 is equipped with switches (first switch 13a, second switch 13b, and third switch 13c) corresponding to each transmission line connected to each of the multiple power transmission units, which supply power to the corresponding transmission line and stop the power supply. For example, the first switch 13a is provided corresponding to the first transmission line 16a, and supplies power to the first transmission line 16a and stops the power supply. The second switch 13b is provided corresponding to the second transmission line 16b, and supplies power to the second transmission line 16b and stops the power supply. The third switch 13c is provided corresponding to the third transmission line 16c, and supplies power to the third transmission line 16c and stops the power supply.

[0064] When the distribution circuit 12 is configured to connect multiple power transmission units in parallel to a single high-frequency power supply 11, as shown in Figure 2, each switch is connected in series to its corresponding transmission line. In this case, when the switch is closed, the high-frequency power supply and the corresponding transmission line are connected, and the power output from the high-frequency power supply is transmitted to the corresponding transmission line. On the other hand, when the switch is open, the high-frequency power supply and the corresponding transmission line are disconnected, and the transmission of power output from the high-frequency power supply to the corresponding transmission line is stopped.

[0065] On the other hand, if the distribution circuit 12 is configured to connect multiple power transmission units in series to a single high-frequency power supply 11, as shown in Figure 3, each switch is connected in parallel to the corresponding transmission line. In this case, when a switch is open, the switch is in an open state, and the power output from the high-frequency power supply is transmitted to the corresponding transmission line. On the other hand, when a switch is closed, the switch is in a short-circuit state, and the power output from the high-frequency power supply passes through the switch, stopping the transmission of power to the corresponding transmission line.

[0066] These switches are controlled by the control unit 18. The control unit 18 determines whether or not to transmit power from each power transmission unit, and based on the determination result, controls the switch corresponding to the transmission line connected to the power transmission unit that was determined.

[0067] The decision of whether or not to transmit power from the power transmission unit is made, for example, by determining whether the power transmission unit in question forms a wireless coupler. For example, the control unit 18 may acquire location information for each electric mobility device 2 and, based on that location information, determine whether or not a wireless coupler has been formed between one power transmission unit and the receiving unit of the electric mobility device 2. Alternatively, the control unit 18 may determine whether or not a wireless coupler has been formed between one power transmission unit and the receiving unit of the electric mobility device 2 by determining whether or not a wireless signal (radio waves, light, etc.) transmitted from the electric mobility device 2 is received by a receiver installed near each power transmission unit.

[0068] If the control unit 18 determines that the power transmission unit being evaluated forms a wireless coupler, it determines that the power transmission unit will transmit power and controls the switch corresponding to the transmission line connected to the power transmission unit so that power is transmitted to that transmission line. If the control unit 18 determines that the power transmission unit being evaluated does not form a wireless coupler, it determines that the power transmission unit will not transmit power and controls the switch corresponding to the transmission line connected to the power transmission unit so that power is stopped to that transmission line.

[0069] For the sake of explanation, the control unit 18 is shown as determining whether the power transmission unit to be judged forms a wireless coupler and then deciding whether or not to transmit power from the power transmission unit. However, the control unit 18 may also determine whether the power transmission unit to be judged forms a wireless coupler based on the positional relationship of the electric mobility 2, etc., without having to determine whether the power transmission unit to be judged forms a wireless coupler.

[0070] Furthermore, a control unit 18 that immediately controls a switch corresponding to the transmission line connected to the corresponding power transmission unit based on a determination of whether the power transmission unit being judged forms a wireless coupler is also included in the concept of the present invention, which is to "control each switch based on whether or not the corresponding power transmission unit transmits power."

[0071] Furthermore, when the control unit 18 determines whether or not to transmit power from the power transmission unit, it may, in addition to determining whether the power transmission unit being considered forms a wireless coupler, also determine the charge state of the battery of the electric mobility device 2 to be powered. That is, if the power transmission unit being considered forms a wireless coupler, the control unit 18 may receive the charge state of the battery of the electric mobility device 2 having a power receiving unit that forms a wireless coupler from the electric mobility device 2, and if the battery is fully charged, it may determine not to transmit power from the power transmission unit and control the corresponding switch.

[0072] As shown in Figures 2 and 3, the distribution circuit 12 also has a primary side compensation circuit for the coupler and a compensation circuit for the transmission line connected in cascaded order between the switch and the transmission line to each power transmission section.

[0073] Specifically, for the first power transmission unit 17a, the first coupler primary side compensation circuit 141a and the first transmission line compensation circuit 15a are connected in cascaded order between the first switch 13a and the first transmission line 16a. For the second power transmission unit 17b, the second coupler primary side compensation circuit 141b and the second transmission line compensation circuit 15b are connected in cascaded order between the second switch 13b and the second transmission line 16b. For the third power transmission unit 17c, the third coupler primary side compensation circuit 141c and the third transmission line compensation circuit 15c are connected in cascaded order between the third switch 13c and the third transmission line 16c.

[0074] Furthermore, each primary-side compensation circuit for a coupler (first coupler primary-side compensation circuit 141a, second coupler primary-side compensation circuit 141b, third coupler primary-side compensation circuit 141c) is positioned closer to the high-frequency power supply 11 than the compensation circuits for the transmission line (first transmission line compensation circuit 15a, second transmission line compensation circuit 15b, third transmission line compensation circuit 15c).

[0075] Here, with reference to Figures 4 and 5, the transmission line compensation circuit and the coupler compensation circuit (primary-side compensation circuit for the coupler and secondary-side compensation circuit for the coupler) provided in accordance with each power transmission section will be explained. Figure 4(a) is a diagram illustrating the transmission line compensation circuit and the coupler compensation circuit (primary-side compensation circuit for the coupler and secondary-side compensation circuit for the coupler), and Figure 4(b) is a diagram illustrating the characteristics of the transformer and gyrator. Figure 5 shows the characteristics when two transformers are connected in cascaded order, when two gyrators are connected in cascaded order, when a transformer and a gyrator are connected in cascaded order, and when a gyrator and a transformer are connected in cascaded order.

[0076] Figure 4(a) illustrates the first transmission line compensation circuit 15a and the first coupler compensation circuit 14a provided for the first wireless coupler 30a formed by the first power transmission unit 17a and the first power receiving unit 21a. The following description will also focus on the first transmission line compensation circuit 15a and the first coupler compensation circuit 14a.

[0077] Furthermore, regardless of which receiving unit forms the first wireless coupler 30a on the power receiving device side, the first transmission line compensation circuit 15a and the first coupler compensation circuit 14a have the same configuration. Also, the second transmission line compensation circuit 15b and the second coupler compensation circuit 14b provided for the second power transmission unit 17b, and the third transmission line compensation circuit 15c and the third coupler compensation circuit 14c provided for the third power transmission unit 17c, have the same configuration as the first transmission line compensation circuit 15a and the first coupler compensation circuit 14a, regardless of which receiving unit forms the second wireless coupler 30b or the third wireless coupler 30c with them. Therefore, further explanation of these is omitted.

[0078] The first transmission line compensation circuit 15a is a circuit that compensates for the deviation in reactance in the first transmission line 16a. The first coupler compensation circuit 14a is a circuit that compensates for the deviation in reactance in the first wireless coupler 30a by comprising the first coupler primary side compensation circuit 141a provided on the power transmission device 10 side and the first coupler secondary side compensation circuit 142a provided on the first power receiving device 20a side, which constitute the first coupler compensation circuit 14a.

[0079] Here, the operation of the high-frequency power supply 11 changes significantly depending on the input impedance. In particular, if the imaginary part of the input impedance seen from the high-frequency power supply 11 to the battery (load) side of the electric mobility 2 becomes large, energy loss occurs in the high-frequency power supply 11, which may cause thermal damage to switching elements and other elements. In addition, reactive power is generated by the imaginary part of the input impedance, so the power supplied from the high-frequency power supply 11 to the battery decreases, leading to a decrease in power supply efficiency.

[0080] The first transmission line compensation circuit 15a and the first coupler compensation circuit 14a each compensate for the deviation in reactance, thereby adjusting the imaginary part of the input impedance as seen from the high-frequency power supply 11 to be approximately zero. Here, adjusting the imaginary part of the input impedance as seen from the high-frequency power supply 11 to be approximately zero means adjusting the imaginary part of the input impedance as seen from the high-frequency power supply 11 to be ideally zero, and it means allowing the imaginary part of the input impedance to deviate from zero due to implementation errors.

[0081] Specifically, the first transmission line compensation circuit 15a is configured to have the characteristics of a transformer or gyrator through the first transmission line 16a and the first transmission line compensation circuit 15a. Furthermore, the first coupler compensation circuit 14a is configured to have the characteristics of a transformer or gyrator through the first wireless coupler 30a and the first coupler primary compensation circuit 141a and first coupler secondary compensation circuit 142a, which constitute the first coupler compensation circuit 14a.

[0082] Here, as shown in Figure 4(b), the characteristics of a transformer mean that the F-parameter (vertical continuation) is a diagonal matrix (a square matrix where all elements except the diagonal elements from the top left to the bottom right are zero), and the characteristics of a gyrator mean that the F-parameter (vertical continuation) is an opposite-angle matrix (a square matrix where all elements except the opposite-angle elements from the bottom left to the top right are zero).

[0083] When two identical transformers and gyrators are connected in cascades, they exhibit the characteristics of a transformer, as shown in Figure 5. Specifically, when two transformers are connected in cascades, the overall F-parameter can be calculated by multiplying the F-parameters of each transformer, resulting in a diagonal matrix that represents the characteristics of the transformer. Similarly, when two gyrators are connected in cascades, the overall F-parameter also becomes a diagonal matrix that represents the characteristics of the transformer.

[0084] On the other hand, when two different types of transformers and gyrators are connected in cascades, they exhibit the characteristics of a gyrator, as shown in Figure 5. That is, when a transformer is connected in cascades before a gyrator, the overall F-parameter becomes an opposite-angle matrix, which is characteristic of a gyrator. Similarly, when a gyrator is connected in cascades before a transformer, the overall F-parameter also becomes an opposite-angle matrix, which is characteristic of a gyrator.

[0085] As a result, the first transmission line 16a and the compensation circuit 15a for the first transmission line give the characteristics of a transformer or gyrator, and the first wireless coupler 30a and the primary-side compensation circuit 141a and secondary-side compensation circuit 142a for the first coupler, which constitute the first coupler compensation circuit 14a, give the characteristics of a transformer or gyrator. In this way, the contactless power supply system 1 can treat the first transmission line 16a, the compensation circuit 15a for the first transmission line, the first wireless coupler 30a, and the compensation circuit 14a for the first coupler, which correspond to the first power transmission unit 17a, as equivalent to a single transformer or gyrator.

[0086] Furthermore, the transformer and gyrator have the impedance conversion characteristics shown in Figure 4(b). That is, when the load impedance connected to the transformer or gyrator is Zl, the input impedance Zin of a transformer with a transformation ratio of n is n 2 Zl is the input impedance Zin of a gyrator with gyration resistance rg, which is rg 2 It becomes / Zl.

[0087] Therefore, if the impedance of the rectifier circuit and battery connected to the output side of the first wireless coupler 30a (first power receiving device 20a) is configured to have only a real part (only a resistive component), the contactless power supply system 1 can have only a real part, with the imaginary part of the input impedance of the first power transmission unit 17a as seen from the high-frequency power supply 11 being approximately zero.

[0088] Furthermore, the contactless power supply system 1 is provided with a transmission line compensation circuit and a coupler compensation circuit for each power transmission unit capable of distributing the high-frequency power output from the high-frequency power supply 11. Each transmission line compensation circuit is configured to have the characteristics of a transformer or gyrator together with the transmission line connected to the corresponding power transmission unit. Similarly, each coupler compensation circuit is configured with a primary-side compensation circuit and a secondary-side compensation circuit for the coupler so that they have the characteristics of a transformer or gyrator together with the wireless coupler configured by the corresponding power transmission unit.

[0089] Therefore, even if the contactless power supply system 1 distributes the high-frequency power output from the high-frequency power supply 11 to each power transmission unit installed at any location, the imaginary part of the input impedance of each power transmission unit as seen from the high-frequency power supply 11 can be set to approximately zero, leaving only the real part. Moreover, even if the lengths of the transmission lines connected to each power transmission unit are different, the different phase delay amounts due to the difference in transmission line lengths can be compensated by the respective transmission line compensation circuits, and in each case, the imaginary part of the input impedance of each power transmission unit as seen from the high-frequency power supply 11 can be set to approximately zero, leaving only the real part.

[0090] Therefore, as shown in Figure 2, even when multiple power transmission units are connected in parallel to the high-frequency power supply 11, and as shown in Figure 3, even when multiple power transmission units are connected in series to the high-frequency power supply 11, the combined input impedance of the power transmission units connected to the high-frequency power supply 11 by the switch will have a real part with an imaginary part of approximately zero.

[0091] As a result, the contactless power supply system 1 can suppress the risk of energy loss in the high-frequency power supply 11 and thermal damage to switching elements and other elements. Furthermore, since the contactless power supply system 1 can suppress the generation of reactive power, it can maintain high power supply efficiency from the high-frequency power supply 11 to the battery. Therefore, the contactless power supply system 1 can operate stably while distributing the high-frequency power output from the high-frequency power supply 11 to each power transmission unit installed at any desired location.

[0092] Here, as shown in Figure 4(b), the transformer outputs a constant voltage when a constant voltage is input, and outputs a constant current when a constant current is input. Thus, when the transmission lines, transmission line compensation circuits, wireless couplers, and coupler compensation circuits corresponding to each power transmission section are configured as a single transformer, the preferred configuration of the distribution circuit 12 is determined as shown in Figure 6, depending on the type of high-frequency power supply 11 (constant voltage source or constant current source).

[0093] First, Figure 6(a) is a circuit diagram showing an example of a distribution circuit 12 when the transmission line, the compensation circuit for the transmission line, the wireless coupler, and the compensation circuit for the coupler are considered as a single transformer, and the high-frequency power supply 11 is a constant voltage source. In this case, it is preferable that the distribution circuit 12 be configured to connect multiple power transmission units in parallel to the high-frequency power supply 11. Since a constant voltage is output from the high-frequency power supply 11, a constant voltage is output to the battery (load) in the path where the switch is closed.

[0094] Therefore, even if the resistance value of the battery (load) connected to each power transmission unit fluctuates, a constant voltage is maintained and output to each battery (load), thus achieving stable power supply operation. In addition, in the path where the switch is open, the power supply from the high-frequency power supply 11 is suppressed, so the overall output power of the high-frequency power supply 11 can be reduced, thereby saving power.

[0095] Next, Figure 6(b) is a circuit diagram showing an example of a distribution circuit 12 when the transmission line, the compensation circuit for the transmission line, the wireless coupler, and the compensation circuit for the coupler are considered as a single transformer, and the high-frequency power supply 11 is a constant current source. In this case, it is preferable that the distribution circuit 12 be configured to connect multiple power transmission units in series with respect to the high-frequency power supply 11. Since a constant current is output from the high-frequency power supply 11, a constant current is output to the battery (load) in the path where the switch is open.

[0096] Therefore, even if the resistance value of the battery (load) connected to each power transmission unit fluctuates, a constant current is maintained and output to each battery (load), thus achieving stable power supply operation. In addition, in the path where the switch is closed, the power supply from the high-frequency power supply 11 is suppressed, so the overall output power of the high-frequency power supply 11 can be reduced, thereby saving power.

[0097] On the other hand, as shown in Figure 4(b), the gyrator outputs a constant current when a constant voltage is input, and outputs a constant voltage when a constant current is input. Thus, when the transmission line, transmission line compensation circuit, wireless coupler, and coupler compensation circuit corresponding to each power transmission section are configured as a single gyrator, the preferred configuration of the distribution circuit 12 is determined as shown in Figure 7, depending on the type of high-frequency power supply 11 (constant voltage source or constant current source).

[0098] First, Figure 7(a) is a circuit diagram showing an example of a distribution circuit 12 when the transmission line, the compensation circuit for the transmission line, the wireless coupler, and the compensation circuit for the coupler are considered as a single gyrator, and the high-frequency power supply 11 is a constant voltage source. In this case, it is preferable that the distribution circuit 12 be configured to connect multiple power transmission units in parallel to the high-frequency power supply 11. Since a constant voltage is output from the high-frequency power supply 11, a constant current is output to the battery (load) in the path where the switch is closed.

[0099] Therefore, even if the resistance value of the battery (load) connected to each power transmission unit fluctuates, a constant current is maintained and output to each battery (load), thus achieving stable power supply operation. In addition, in the path where the switch is open, the power supply from the high-frequency power supply 11 is suppressed, so the overall output power of the high-frequency power supply 11 can be reduced, thereby saving power.

[0100] Next, Figure 7(b) is a circuit diagram showing an example of a distribution circuit 12 when the transmission line, the compensation circuit for the transmission line, the wireless coupler, and the compensation circuit for the coupler are considered as a single gyrator, and the high-frequency power supply 11 is a constant current source. In this case, it is preferable that the distribution circuit 12 be configured to connect multiple power transmission units in series with respect to the high-frequency power supply 11. Since a constant current is output from the high-frequency power supply 11, a constant voltage is output to the battery (load) in the path where the switch is open.

[0101] Therefore, even if the resistance value of the battery (load) connected to each power transmission unit fluctuates, a constant voltage is maintained and output to each battery (load), thus achieving stable power supply operation. In addition, in the path where the switch is closed, the power supply from the high-frequency power supply 11 is suppressed, so the overall output power of the high-frequency power supply 11 can be reduced, thereby saving power.

[0102] As described above, four possible configurations are conceivable based on the combination of the overall circuit characteristics (transformer or gyrator) of the transmission line, transmission line compensation circuit, wireless coupler, and coupler compensation circuit corresponding to each power transmission section, and the type of high-frequency power supply 11 (constant voltage source or constant current source). The choice of configuration may be determined according to the characteristics of the application.

[0103] Next, the design methods for compensation circuits for transmission lines and couplers will be explained with reference to Figures 8 to 12.

[0104] First, Figure 8(a) is a circuit diagram showing the configuration of the transmission line compensation circuit when it is implemented as a T-type circuit. Figure 8(b) is a circuit diagram showing the configuration of the transmission line compensation circuit when it is implemented as a π-type circuit. Figure 8(c) shows the calculation formulas for the reactance of each element when the transmission line compensation circuit is configured as a T-type circuit and as a π-type circuit, respectively, for the case where the circuit characteristics of the combination of the transmission line compensation circuit and the transmission line are as a transformer and as a gyrator. The reactances X1, X2, and X3 of each element shown in Figure 8(c) correspond to the reactances X1, X2, and X3 of each element shown in Figures 8(a) and 8(b).

[0105] The circuit characteristics (transformer or gyrator) resulting from the combination of the transmission line compensation circuit and the transmission line, and the circuit configuration of the transmission line compensation circuit (T-type circuit or π-type circuit), are determined based on the specifications required for the application. Furthermore, if the circuit characteristics are those of a transformer, the transformation ratio n of the transformer is determined according to the required specifications; if the circuit characteristics are those of a gyrator, the gyration resistance rg of the gyrator is determined according to the required specifications. Then, based on the characteristic impedance Zc and phase delay Φ of the connected transmission line, the values ​​of the reactances X1, X2, and X3 of each element are determined using the calculation formulas corresponding to the determined circuit characteristics and circuit configuration shown in Figure 8(c).

[0106] Next, Figure 9 shows the possible connection methods for the coupler compensation circuit when the wireless coupler is configured using an electric field coupling method, the topology of the coupler compensation circuit and wireless coupler for each connection method, the formulas for calculating the reactance of the primary and secondary compensation circuits for the coupler for each connection method, and the formulas for calculating the circuit characteristics obtained from the coupler compensation circuit and wireless coupler and their transformation ratio or gyration resistance for each connection method.

[0107] As shown in the topology of Figure 9, a wireless coupler using the electric field coupling method is represented by an equivalent circuit in which three capacitors (C1, C2, Cc) are connected in a π-type configuration. By connecting a primary-side compensation circuit for the coupler, consisting of inductor L1, to the primary side (input side, transmitting side, high-frequency power supply side) of such an equivalent circuit wireless coupler using the electric field coupling method, and connecting a secondary-side compensation circuit for the coupler, consisting of inductor L2, to the secondary side (output side, receiving side, load side), the circuit characteristics of a transformer or gyrator can be obtained by combining the coupler compensation circuit and the wireless coupler.

[0108] Here, the primary compensation circuit for the coupler can be implemented by connecting inductor L1 in series with the input of the wireless coupler, or by connecting inductor L1 in parallel with the input of the wireless coupler. Furthermore, the secondary compensation circuit for the coupler can be implemented by connecting inductor L2 in series with the output of the wireless coupler, or by connecting inductor L2 in parallel with the output of the wireless coupler.

[0109] In the case of the SS (Single Series) method, where the coupler compensation circuit is connected in series with the input of the wireless coupler as the primary compensation circuit and inductor L2 is connected in series with the output of the wireless coupler as the secondary compensation circuit, the circuit configuration of the coupler compensation circuit and wireless coupler is a gyrator. Similarly, in the case of the PP (Pull-Pull) method, where the coupler compensation circuit is connected in parallel with the input of the wireless coupler as the primary compensation circuit and inductor L2 is connected in parallel with the output of the wireless coupler as the secondary compensation circuit, the circuit configuration of the coupler compensation circuit and wireless coupler is also a gyrator. In these cases, the gyration resistance rg of the gyrator is calculated using the formula shown in Figure 9.

[0110] On the other hand, in the SP method, where the coupler compensation circuit connection method involves connecting inductor L1 in series with the input of the wireless coupler as the primary compensation circuit and inductor L2 in parallel with the output of the wireless coupler as the secondary compensation circuit, the circuit configuration resulting from the combination of the coupler compensation circuit and the wireless coupler is a transformer. Similarly, in the PS method, where the coupler compensation circuit connection method involves connecting inductor L1 in parallel with the input of the wireless coupler as the primary compensation circuit and inductor L2 in series with the output of the wireless coupler as the secondary compensation circuit, the circuit configuration resulting from the combination of the coupler compensation circuit and the wireless coupler is also a transformer. In these cases, the transformation ratio n of the transformer is calculated using the formula shown in Figure 9.

[0111] When a wireless coupler is configured using an electric field coupling method, the circuit characteristics (transformer or gyrator) of the combination of the transmission line compensation circuit and the transmission line are determined based on the specifications required for the application in which it will be used. Then, the connection method for the primary and secondary compensation circuits of the coupler is determined from the SS method, PP method, SP method, and PS method. Based on the determined connection method, the inductance of inductor L1 of the primary compensation circuit of the coupler and the inductance of inductor L2 of the secondary compensation circuit of the coupler are determined using the calculation formula shown in Figure 9.

[0112] Figure 10 also shows the possible connection methods for the coupler compensation circuit when the wireless coupler is configured using a magnetic field coupling method, the topology of the coupler compensation circuit and wireless coupler for each connection method, the formulas for calculating the reactance of the primary and secondary compensation circuits for the coupler for each connection method, and the formulas for calculating the circuit characteristics obtained from the coupler compensation circuit and wireless coupler and their transformation ratio or gyration resistance for each connection method.

[0113] A wireless coupler using a magnetic field coupling method is represented as a transformer in which two inductors (L1, L2) are coupled with a coupling coefficient k, as shown in the topology of Figure 9. By connecting a primary-side compensation circuit for the coupler, consisting of capacitor C1, to the primary side (input side, transmission side, high-frequency power supply side) of such a wireless coupler using a magnetic field coupling method, and connecting a secondary-side compensation circuit for the coupler, consisting of capacitor C2, to the secondary side (output side, receiving side, load side), the circuit characteristics of a transformer or gyrator can be obtained by combining the coupler compensation circuit and the wireless coupler.

[0114] Here, the primary compensation circuit for the coupler can be implemented by connecting capacitor C1 in series with the input of the wireless coupler, or by connecting capacitor C1 in parallel with the input of the wireless coupler. Furthermore, the secondary compensation circuit for the coupler can be implemented by connecting capacitor C2 in series with the output of the wireless coupler, or by connecting capacitor C2 in parallel with the output of the wireless coupler.

[0115] In the case of the SS (Single Series) method, where capacitor C1 is connected in series with the input of the wireless coupler as the primary compensation circuit and capacitor C2 is connected in series with the output of the wireless coupler as the secondary compensation circuit, the circuit configuration of the coupler compensation circuit and wireless coupler is a gyrator. Similarly, in the PP (Push-Push) method, where capacitor C1 is connected in parallel with the input of the wireless coupler as the primary compensation circuit and capacitor C2 is connected in parallel with the output of the wireless coupler as the secondary compensation circuit, the circuit configuration of the coupler compensation circuit and wireless coupler is also a gyrator. In these cases, the gyration resistance rg of the gyrator is calculated using the formula shown in Figure 10.

[0116] On the other hand, in the SP method, where the coupler compensation circuit is connected in series with the input of the wireless coupler as the primary compensation circuit and capacitor C2 is connected in parallel with the output of the wireless coupler as the secondary compensation circuit, the circuit configuration of the coupler compensation circuit and the wireless coupler is a transformer. Similarly, in the PS method, where the coupler compensation circuit is connected in parallel with the input of the wireless coupler as the primary compensation circuit and capacitor C2 is connected in series with the output of the wireless coupler as the secondary compensation circuit, the circuit configuration of the coupler compensation circuit and the wireless coupler is also a transformer. In these cases, the transformation ratio n of the transformer is calculated using the formula shown in Figure 10.

[0117] When a wireless coupler is configured using a magnetic field coupling method, similar to the case of an electric field coupling method, the circuit characteristics (transformer or gyrator) of the combination of the transmission line compensation circuit and the transmission line are determined based on the specifications required for the application in which it will be used. Then, the connection method for the primary and secondary compensation circuits of the coupler is determined from the SS method, PP method, SP method, and PS method. Based on the determined connection method, the capacitance of capacitor C1 of the primary compensation circuit of the coupler and the capacitance of capacitor C2 of the secondary compensation circuit of the coupler are determined using the calculation formula shown in Figure 10.

[0118] Note that the inductance of inductor L1 or capacitance of capacitor C1 of the primary-side compensation circuit for the coupler, determined by the calculation formula shown in Figure 9 or Figure 10, is the value when the primary-side compensation circuit for the coupler is directly connected to the input side of the wireless coupler. On the other hand, as described above with reference to Figures 2 and 3, the contactless power supply system 1 places the primary-side compensation circuit for the coupler on the high-frequency power supply 11 side of the transmission line compensation circuit, more specifically, between the switch and the transmission line compensation circuit. This is because the primary-side compensation circuit for the coupler is placed together with the transmission line compensation circuit within the distribution circuit 12.

[0119] When the primary-side compensation circuit for the coupler is located on the high-frequency power supply 11 side of the transmission line compensation circuit, the impedance of the primary-side compensation circuit for the coupler can be determined by performing an impedance transformation as shown in Figures 11 and 12 on the inductance of the inductor L1 or the capacitance of the capacitor C1 of the primary-side compensation circuit for the coupler, which is determined by the calculation formulas shown in Figures 9 and 10.

[0120] For example, Figure 11(a) shows an impedance transformation when an inductor or capacitor with reactance Xs (impedance jXs), which is connected in series with the input side of a wireless coupler as a primary-side compensation circuit for a coupler, is moved to the high-frequency power supply 11 side of the transmission line compensation circuit, which together with the transmission line constitutes a transformer with a transformation ratio n. In this case, the primary-side compensation circuit for the coupler, which is provided on the high-frequency power supply 11 side of the transmission line compensation circuit, has a reactance of n 2 Xs(impedance jn 2 An inductor or capacitor that is Xs) is connected in series with the wireless coupler.

[0121] Furthermore, Figure 11(b) shows the impedance transformation when an inductor or capacitor with reactance Xp (impedance jXp), which is connected in parallel to the input side of the wireless coupler as a primary-side compensation circuit for the coupler, is moved to the high-frequency power supply 11 side than the transmission line compensation circuit which constitutes a transformer with transformation ratio n together with the transmission line. In this case, the primary-side compensation circuit for the coupler, which is provided on the high-frequency power supply 11 side than the transmission line compensation circuit, has reactance n 2 Xp(impedance jn 2 An inductor or capacitor that is Xs) is connected in parallel to the wireless coupler.

[0122] Furthermore, Figure 12(a) shows the impedance transformation when an inductor or capacitor with reactance Xs (impedance jXs) connected in series to the input side of the wireless coupler as a primary-side compensation circuit for the coupler is moved to the high-frequency power supply 11 side, which is further away from the transmission line compensation circuit that constitutes a gyrator with gyration resistance rg together with the transmission line. In this case, the primary-side compensation circuit for the coupler, which is located on the high-frequency power supply 11 side, has a reactance of -rg 2 / Xs(impedance-jrg 2 An inductor or capacitor with a coefficient of Xs ( / Xs) is connected in parallel to the wireless coupler.

[0123] Further, FIG. 12(b) is a diagram showing impedance conversion when a reactor or capacitor of reactance Xp (impedance jXp) connected in parallel to the input side of a wireless coupler as a primary-side compensation circuit for the coupler is moved to the high-frequency power supply 11 side from the compensation circuit for the transmission line that constitutes the gyrator of the gyration resistance rg together with the transmission line. In this case, the primary-side compensation circuit for the coupler provided on the high-frequency power supply 11 side from the compensation circuit for the transmission line has a reactance of -rg 2 / Xp (impedance -jrg 2 / Xp), and an inductor or capacitor having this value is connected in series to the wireless coupler.

[0124] As described above, for each power transmission unit that can distribute the high-frequency power output from the high-frequency power supply 11, the non-contact power supply system 1 designs a compensation circuit for the transmission line so as to have the characteristics of a transformer or a gyrator together with the transmission line connected to the power transmission unit, and also designs a primary-side compensation circuit for the coupler and a secondary-side compensation circuit for the coupler so as to have the characteristics of a transformer or a gyrator together with the wireless coupler constituted by the corresponding power transmission unit.

[0125] Next, referring to FIGS. 13 and 14, simulation results of an example of the non-contact power supply system 1 designed by the method described above are shown. FIG. 13(a) is a diagram showing the equivalent circuit of the designed non-contact power supply system 1, and FIG. 13(b) is a diagram showing the values of the parameters of the equivalent circuit shown in FIG. 13(a) designed by the method described above. Further, FIG. 14 is a diagram showing the simulation results.

[0126] As shown in FIG. 13(a), the non-contact power supply system 1 to be designed is configured such that two power transmission units are connected in parallel to a high-frequency power supply 11 operating as a constant voltage source. Also, in each power transmission unit, a wireless coupler using the electric field coupling method is configured. Note that the non-contact power supply system 1 uses a differential line as the transmission line, and the wireless coupler also operates differentially.

[0127] Based on this, for each power transmission section, a transmission line compensation circuit (capacitor C1, capacitor C2, inductor L2) was designed, which, when combined with the transmission line of that power transmission section, results in the characteristics of a transformer 41 with a transformation ratio n1 of 0.833, and is composed of a π-type circuit.

[0128] Furthermore, for each power transmission section, a primary-side compensation circuit (inductor L1) and a secondary-side compensation circuit (inductor L3) for the coupler were designed, connected in a PS (Power Stability) manner to achieve the characteristics of a transformer 42 with a transformation ratio n2 of 1.2 when combined with the wireless coupler composed of that power transmission section.

[0129] By designing in this way, when the transmission line, transmission line compensation circuit, wireless coupler, and coupler compensation circuit are considered as a single transformer, the transformation ratio n is n1 × n2 = 1.0. The primary side compensation circuit for the coupler (inductor L1) underwent impedance conversion based on the transformer 41, which is composed of the transmission line and the transmission line compensation circuit (see Figure 11(b)).

[0130] Based on the above, the values ​​of each parameter in the equivalent circuit shown in Figure 13(a) were as shown in Figure 13(b) as a result of designing using the method described above. For the equivalent circuit shown in Figure 13(a) with these parameter values, a constant voltage of 100Vrms (effective value) and 6.78MHz was input as the high-frequency power supply 11, and the output voltage v1, which is the voltage output to the load resistor Rl1 (50Ω) connected to the output of the wireless coupler in one of the power transmission sections, and the output voltage v2, which is the voltage output to the load resistor Rl2 (100Ω) connected to the output of the wireless coupler in the other power transmission section, were calculated by simulation.

[0131] As a result, as shown in Figure 14, it was found that the output voltages v1 and v2 were the same as the input voltage vs, even when the resistance values ​​of the load resistors Rl1 and Rl2 were different. This is because the transmission line compensation circuit and the coupler compensation circuit were designed so that the transmission line, transmission line compensation circuit, wireless coupler, and coupler compensation circuit all exhibited the characteristics of a single transformer (transformation ratio n=1.0).

[0132] Next, with reference to Figures 15 and 16, the simulation results of another example of the contactless power supply system 1 designed using the method described above are shown. Figure 15(a) is a diagram showing the equivalent circuit of the designed contactless power supply system 1, and Figure 15(b) is a diagram showing the values ​​of each parameter of the equivalent circuit shown in Figure 15(a) designed using the method described above. Figure 16 is a diagram showing the simulation results.

[0133] As shown in Figure 15(a), the contactless power supply system 1 designed consists of two power transmission units connected in series to a high-frequency power supply 11 that operates as a constant current source. In addition, each power transmission unit is configured with a wireless coupler using an electric field coupling method. Furthermore, the contactless power supply system 1 uses a differential transmission line, and the wireless coupler also operates differentially.

[0134] Based on this, for each power transmission section, a transmission line compensation circuit (inductor L1, capacitor C2, inductor L2) was designed, consisting of a T-type circuit that, when combined with the transmission line of that power transmission section, produces the characteristics of a gyrator 43 with a gyration resistance rg1 of 60Ω.

[0135] Furthermore, for each power transmission section, a primary-side compensation circuit (capacitor C1) and a secondary-side compensation circuit (inductor L3) for the coupler were designed, connected in a PS (Power Stability) manner to achieve the characteristics of a transformer 44 with a transformation ratio n2 of 1.2 when combined with the wireless coupler composed of that power transmission section.

[0136] By designing in this way, when the transmission line, transmission line compensation circuit, wireless coupler, and coupler compensation circuit are considered as a single gyrator, its gyration resistance rg is set to rg1 / n2 = 50Ω.

[0137] The primary side compensation circuit for the coupler (capacitor C1) performs impedance conversion based on the gyrator 43, which is composed of the transmission line and the transmission line compensation circuit (see Figure 12(b)). Therefore, the primary side compensation circuit for the coupler, which is connected in parallel with the wireless coupler in the PS method, is connected in series with the wireless coupler (transmitter section) by moving it to the high-frequency power supply 11 side of the transmission line compensation circuit, across the gyrator 43.

[0138] Based on the above, the values ​​of each parameter in the equivalent circuit shown in Figure 15(a) were as shown in Figure 15(b) as a result of designing using the method described above. For the equivalent circuit shown in Figure 15(a) with these parameter values, a constant current with a power supply current Is (effective value) of 1Arms and a frequency of 6.78MHz was input as a high-frequency power supply 11, and the output voltage v1, which is the voltage output to the load resistor Rl1 (50Ω) connected to the output of the wireless coupler in one of the power transmission sections, and the output voltage v2, which is the voltage output to the load resistor Rl2 (100Ω) connected to the output of the wireless coupler in the other power transmission section, were calculated by simulation.

[0139] As a result, as shown in Figure 14, it was found that both output voltages v1 and v2 output voltages of 50Vrms are output even if the resistance values ​​of load resistors Rl1 and Rl2 are different. This is because the transmission line compensation circuit, wireless coupler, and coupler compensation circuit were designed so that they have the characteristics of a single gyrator (gyration resistance rg = 50Ω). In other words, the simulation also showed that for a power supply current Is = 1Arms, a voltage of rg × Is = 50Ω × 1Arms = 50Vrms is output as output voltages v1 and v2.

[0140] Next, with reference to Figures 17 to 19, we will show the simulation results of yet another example of the contactless power supply system 1 designed using the method described above. Figure 17 is a diagram showing the equivalent circuit of the designed contactless power supply system 1, and Figure 18 is a diagram showing the values ​​of each parameter of the equivalent circuit shown in Figure 17, designed using the method described above. Figure 19 is a diagram showing the simulation results.

[0141] As shown in Figure 17, the contactless power supply system 1 designed is configured by adding one more power transmission unit in parallel to the high-frequency power supply 11, which operates as a constant voltage source, compared to the equivalent circuit shown in Figure 13(a). In other words, in this example, three power transmission units are connected in parallel to the high-frequency power supply 11, which operates as a constant voltage source.

[0142] Furthermore, each power transmission unit is configured with a wireless coupler using an electric field coupling method. In addition, the contactless power supply system 1 uses a differential transmission line, and the wireless coupler also operates differentially. However, the transmission line length (phase delay) of the transmission line connected to the newly added power transmission unit compared to Figure 13(a), and the inter-electrode capacitance of the wireless coupler configured by that power transmission unit, are both different from the values ​​for the other power transmission units (see Figure 18).

[0143] Based on this, for the power transmission section newly added to Figure 13(a), a transmission line compensation circuit (inductor L5, inductor L6, capacitor C5) was designed, which, when combined with the transmission line of the power transmission section, results in the characteristics of a transformer 45 with a transformation ratio n3 of 0.375, consisting of a π-type circuit.

[0144] Furthermore, for the power transmission section, a primary-side compensation circuit (inductor L4) and a secondary-side compensation circuit (inductor L7) for the coupler were designed, connected in a PS (Power Stability) manner to achieve the characteristics of a transformer 46 with a transformation ratio n4 of 2.67 when combined with the wireless coupler composed of the power transmission section.

[0145] By designing in this way, when the transmission line, transmission line compensation circuit, wireless coupler, and coupler compensation circuit corresponding to the newly added power transmission section in Figure 13(a) are considered as a single transformer, the transformation ratio n is set to n1 × n2 = 1.0. The primary side compensation circuit for the coupler (inductor L4) underwent impedance conversion based on the transformer 41, which is composed of the transmission line and the transmission line compensation circuit (see Figure 11(b)).

[0146] Based on the above, the values ​​of each parameter in the equivalent circuit shown in Figure 17, as a result of designing using the method described above, are shown in Figure 18. Note that the parameters shown in the equivalent circuit shown in Figure 13(a) are the same as those shown in Figure 13(b).

[0147] For the equivalent circuit shown in Figure 17 with these parameter values, a constant voltage with a power supply voltage Vs (effective value) of 100Vrms and a frequency of 6.78MHz was input as the high-frequency power supply 11. The output voltage v1, which is the voltage output to a load resistor Rl1 (50Ω) connected to the output of a wireless coupler composed of one power transmission unit, the output voltage v2, which is the voltage output to a load resistor Rl2 (100Ω) connected to the output of a wireless coupler composed of another power transmission unit, and the output voltage v3, which is the voltage output to a load resistor Rl3 (25Ω) connected to the output of a wireless coupler composed of yet another power transmission unit were calculated by simulation.

[0148] As a result, as shown in Figure 19, it was found that the output voltages v1, v2, and v3 remained the same as the input voltage vs, even if the corresponding transmission line length and wireless coupler capacity differed for each power transmission section, and even if the resistance values ​​of the connected load resistors Rl1, Rl2, and Rl3 differed. This is because the transmission line compensation circuit and the coupler compensation circuit were designed so that the transmission line, transmission line compensation circuit, wireless coupler, and coupler compensation circuit all exhibited the characteristics of a single transformer with a transformation ratio n=1.0 for each power transmission section.

[0149] Based on the above, the power transmission device 10 and the contactless power supply system 1 according to this embodiment provide the following effects.

[0150] (1) High-frequency power is supplied from the high-frequency power supply 11 to the first power transmission unit 17a, the second power transmission unit 17b, and the third power transmission unit 17c, which are each provided on a separate electric mobility device 2 and are capable of forming a wireless coupler with one of the first power receiving unit 21a of the first power receiving device 20a, the second power receiving unit 21b of the second power receiving device 20b, and the third power receiving unit 21c of the third power receiving device 20c. Then, power is transmitted non-contact from each of the first power transmission unit 17a, the second power transmission unit 17b, and the third power transmission unit 17c to the first power receiving unit 21a, the second power receiving unit 21b, or the third power receiving unit 21c that forms the wireless coupler. The power received by the first power receiving unit 21a, the second power receiving unit 21b, or the third power receiving unit 21c is supplied to the battery (load) of the electric mobility device 2 having the power receiving unit that received the power.

[0151] Here, as described above, the power transmission device 10 does not transmit power to the same receiving device simultaneously, but rather has multiple power transmission units (first power transmission unit 17a, second power transmission unit 17b, and third power transmission unit 17c) each capable of transmitting power to different electric mobility devices 2. The high-frequency power output from the high-frequency power supply 11 is distributed by the distribution circuit 12 to the first power transmission unit 17a, the second power transmission unit 17b, and the third power transmission unit 17c, respectively. The power distributed to the first power transmission unit 17a is transmitted to the first power transmission unit 17a by the first transmission line 16a provided in correspondence with the first power transmission unit 17a, the power distributed to the second power transmission unit 17b is transmitted to the second power transmission unit 17b by the second transmission line 16b provided in correspondence with the second power transmission unit 17b, and the power distributed to the third power transmission unit 17c is transmitted to the third power transmission unit 17c by the third transmission line 16c provided in correspondence with the third power transmission unit 17c.

[0152] In this way, the power transmission device 10 and the contactless power supply system 1 can distribute power from one high-frequency power supply 11 to multiple power transmission units by providing a distribution circuit 12. Furthermore, even if the high-frequency power supply 11 and each power transmission unit are far apart, or if the distances are spaced apart, the power distributed by the distribution circuit 12 can be transmitted through transmission lines provided corresponding to each power transmission unit. Therefore, the flexibility of the layout between the high-frequency power supply 11 and the power transmission units can be improved. In addition, since it is not necessary to provide a high-frequency power supply corresponding to each power transmission device 10, a larger workspace can be secured in the factory where the power transmission devices 10 are installed.

[0153] Furthermore, even when supplying power to the electric mobility devices 2 within the factory while they are in motion, the distribution circuit 12 and each power transmission unit are connected by corresponding transmission lines. Therefore, in order to connect the power transmission unit to the high-frequency power supply 11, it is not necessary to bury the power transmission unit in places where the electric mobility devices 2 do not pass or pass through infrequently. In other words, power distributed by the distribution circuit 12 can be transmitted via transmission lines to power transmission units buried along routes frequently used by the electric mobility devices 2.

[0154] (2) Compensation circuits provided in each of the first, second, and third power transmission units 17a, 17b, and 17c respectively compensate for any deviations in reactance between them. As a result, even if the first, second, and third power transmission units 17a, 17b, and 17c are configured in shapes suited to their respective circumstances and installed in positions suited to their respective circumstances, the compensation circuits can make the imaginary part of the input impedance seen from the high-frequency power supply 11 to the battery (load) side approximately zero. Therefore, the power transmission device 10 and the contactless power supply system 1 can provide stable contactless power supply, thereby improving the flexibility of the layout between the high-frequency power supply 11 and the power transmission units.

[0155] (3) The compensation circuits provided in accordance with the first power transmission unit 17a, the second power transmission unit 17b, and the third power transmission unit 17c each have a transmission line compensation circuit and a coupler compensation circuit. The transmission line compensation circuit compensates for the deviation in reactance in the transmission line connected to the corresponding power transmission unit, and the coupler compensation circuit compensates for the deviation in reactance in the wireless coupler that can be formed by the corresponding power transmission unit. This makes it easy to design the compensation circuits provided in accordance with each power transmission unit by separating them into a transmission line compensation circuit and a coupler compensation circuit. In particular, even if the transmission lines have different line lengths and therefore have different phase delay amounts, the deviation in reactance in each transmission line can be easily compensated by the transmission line compensation circuit alone. Furthermore, since at least the transmission line compensation circuit is provided within the distribution circuit 12, there is no need to provide a separate place to install the transmission line compensation circuit. This improves the flexibility of the layout between the high-frequency power supply 11 and the power transmission unit, and also allows for space savings for the power transmission device 10 in the area where it is installed.

[0156] (4) Each coupler compensation circuit is configured to compensate for the deviation in reactance in the wireless coupler by comprising a primary coupler compensation circuit provided on the power transmission side and a secondary coupler compensation circuit provided on the power receiving side. The primary coupler compensation circuit is located on the high-frequency power supply 11 side of the transmission line compensation circuit and is provided together with the transmission line compensation circuit in the distribution circuit 12. As a result, there is no need to provide a separate place for the primary coupler compensation circuit, which improves the flexibility of the layout between the high-frequency power supply 11 and the power transmission unit, and also allows for further space saving of the power transmission device 10 in the area where the power transmission device 10 is installed.

[0157] (5) The transmission line compensation circuit is configured such that the characteristics of a transformer or gyrator are obtained by the transmission line and the transmission line compensation circuit, and the coupler compensation circuit is configured such that the characteristics of a transformer or gyrator are obtained by the wireless coupler and the coupler compensation circuit. Here, if a transformer or gyrator is provided in the preceding stage and a transformer or gyrator is provided in the succeeding stage and these are connected in cascaded order, the characteristics of a single transformer or gyrator are obtained. Therefore, by configuring the transmission line compensation circuit and the coupler compensation circuit as described above, when looking at the battery to be powered from the high-frequency power supply 11, it can be considered as if the battery is connected via a single transformer or gyrator.

[0158] Therefore, the imaginary part of the input impedance seen from the high-frequency power supply 11 to each battery becomes approximately zero, allowing for stable and efficient power supply from the high-frequency power supply 11 to the batteries. Furthermore, by designing the transmission line compensation circuit to have the characteristics of a transformer or gyrator through the transmission line and the transmission line compensation circuit, and by designing the coupler compensation circuit to have the characteristics of a transformer or gyrator through the wireless coupler and the coupler compensation circuit, a compensation circuit that can stably and efficiently supply power from the high-frequency power supply 11 to the batteries can be easily realized.

[0159] (6) The first transmission line 16a that transmits power to the first power transmission unit 17a, the second transmission line 16b that transmits power to the second power transmission unit 17b, and the third transmission line 16c that transmits power to the third power transmission unit 17c are all made of coaxial cable or shielded cable. This makes it easy to run the first transmission line 16a, the second transmission line 16b, and the third transmission line 16c along walls or the ground. Therefore, even if the installation positions of the first power transmission unit 17a, the second power transmission unit 17b, and the third power transmission unit 17c relative to the high-frequency power supply 11 are arbitrary, the distribution circuit 12 can be easily connected to the first power transmission unit 17a, the second power transmission unit 17b, and the third power transmission unit 17c using the first transmission line 16a, the second transmission line 16b, and the third transmission line 16c, which are made of coaxial cable or shielded cable. Thus, the degree of freedom in the layout between the high-frequency power supply 11 and the power transmission units can be further increased.

[0160] Furthermore, by using coaxial cables or shielded cables as the first transmission line 16a, the second transmission line 16b, and the third transmission line 16c, these transmission lines can be easily attached to and detached from the corresponding power transmission unit. This makes it easy to change the layout of the power transmission unit within the factory. Also, when supplying power to electric mobility devices 2 while they are in motion within the factory, once the power transmission unit is buried, the freedom of the factory layout is limited, and it becomes difficult to change the layout. However, this makes it easy to change the location of the high-frequency power supply 11 and the distribution circuit 12, as well as the wiring layout of each transmission line.

[0161] (7) The distribution circuit 12 is provided with switches (first switch 13a, second switch 13b, and third switch 13c) corresponding to the first transmission line 16a connected to the first power transmission unit 17a, the second transmission line 16b connected to the second power transmission unit 17b, and the third transmission line 16c connected to the third power transmission unit 17c, for supplying power to the corresponding transmission line and for stopping the power supply. Each switch is controlled by the control unit 18 based on whether or not to transmit power from the corresponding power transmission unit.

[0162] This allows the system to control a switch to stop power transmission to transmission lines connected to power transmission units that do not transmit power (for example, those without wireless couplers), thereby suppressing the supply of power to such units. Consequently, it is possible to suppress the wasteful consumption of power and the leakage of unnecessary electromagnetic waves from the power transmission units. Therefore, energy conservation can be achieved and safety can be ensured.

[0163] (8) The high-frequency power supply 11 and the distribution circuit 12 are provided in the same housing as a power supply unit 5. This allows the high-frequency power supply 11 and the distribution circuit 12 to be installed together at a distance from the power transmission unit. This improves the flexibility of the layout between the high-frequency power supply 11 and the power transmission unit, and also helps to further reduce the space required for the power transmission device 10 in the area where it is installed. Furthermore, since the control unit 18 is also installed in the same housing as a power supply unit 5, this improves the flexibility of the layout between the high-frequency power supply 11 and the power transmission unit, and also helps to further reduce the space required for the power transmission device 10 in the area where it is installed.

[0164] In addition, the power transmission device 10 and the contactless power supply system 1 enjoy the effects described for each of the configurations described individually in the above description.

[0165] Although the present invention has been described above based on embodiments, it is easy to infer that the present invention is not limited in any way to the above embodiments, and that various improvements and modifications are possible without departing from the spirit of the present invention. For example, each embodiment, including the modifications described below, may be constructed by modifying the embodiment by adding or replacing some or more parts of the configuration of another embodiment with that embodiment. Furthermore, the numerical values ​​given in the above embodiments are merely examples, and it is naturally possible to use other numerical values.

[0166] In the above embodiment, the case was described in which the power transmission device 10 distributes power to three power transmission units (first power transmission unit 17a, second power transmission unit 17b, and third power transmission unit 17c) from one high-frequency power supply 11 using a distribution circuit 12. In contrast, the power transmission device 10 may distribute power to two or more power transmission units from one high-frequency power supply 11 using a distribution circuit 12. In this case, the switch, transmission line, transmission line compensation circuit, and coupler compensation circuit are provided corresponding to each power transmission unit. Each transmission line compensation circuit is configured to have the characteristics of a transformer or gyrator in combination with the transmission line connected to the corresponding power transmission unit. The coupler compensation circuit is configured to have the characteristics of a transformer or gyrator in combination with the wireless coupler configured by the corresponding power transmission unit.

[0167] In the above embodiment, the configuration of the contactless power supply system 1 was described using three power receiving devices (first power receiving device 20a, second power receiving device 20b, and third power receiving device 20c) provided on separate electric mobility devices 2 as an example. However, the number of power receiving devices capable of receiving power from the power transmission device 10 in the contactless power supply system 1 may be one or more arbitrary numbers.

[0168] In the above embodiment, a case was described in which each of the multiple power receiving devices can form a wireless coupler with any of the multiple power transmitting units, but the invention is not necessarily limited to this. For example, at least one power receiving device may limit the number of power transmitting units that can form a wireless coupler with its power receiving unit from among the multiple power transmitting units. In the design example shown in Figures 17 to 19, for a wireless coupler arranged in three rows vertically, the wireless couplers capable of supplying power to load resistors Rl1 and Rl2 are limited to the top two rows, and the wireless coupler capable of supplying power to load resistor Rl3 is limited to the bottom row. Even in such a case, high-frequency power can be distributed from a single high-frequency power supply 11 to the power transmitting units of each wireless coupler via the distribution circuit 12, and the effects of the present invention can be enjoyed.

[0169] In the above embodiment, the case in which the transmission line compensation circuit is provided within the distribution circuit 12 was described. However, the transmission line compensation circuit may be provided as a separate circuit from the distribution circuit 12, but together with the distribution circuit 12, it may be provided as a power supply unit 5 within the same housing. This also eliminates the need to provide a separate place for the transmission line compensation circuit, improves the flexibility of the layout between the high-frequency power supply 11 and the power transmission unit, and allows for space saving of the power transmission device 10 in the area where the power transmission device 10 is provided.

[0170] In the above embodiment, the case in which the primary-side compensation circuit for the coupler is provided within the distribution circuit 12 was described. However, the primary-side compensation circuit for the coupler may be provided as a separate circuit from the distribution circuit 12, but together with the distribution circuit 12, it may be provided in the same housing as the power supply unit 5. This also eliminates the need to provide a separate place for the primary-side compensation circuit for the coupler, improves the flexibility of the layout between the high-frequency power supply 11 and the power transmission unit, and allows for space saving of the power transmission device 10 in the area where the power transmission device 10 is provided.

[0171] In the above embodiment, the case in which the control unit 18 is provided together with the high-frequency power supply 11 and the distribution circuit 12 within the housing of the power supply unit 5 was described. However, the control unit 18 may be provided outside the housing of the power supply unit 5. For example, if a separate computer is provided to manage the operation of the electric mobility 2, the control unit 18 may be built into that computer. [Explanation of symbols]

[0172] 1. Contactless power supply system 2 Electric Mobility 5 Power supply unit 10 Power transmission equipment 11 High frequency power supply 12 Distribution circuit 13a First Switch 13b Second switch 13c third switch 14a Compensation circuit for first coupler 14b Compensation circuit for second coupler 14c Compensation circuit for third coupler 15a Compensation circuit for the first transmission line 15b Compensation circuit for the second transmission line 15c Compensation circuit for third transmission line 16a First transmission line 16b Second transmission line 16c Third Transmission Line 17a First power transmission section 17b Second power transmission section 17c Third power transmission section 18 Control Unit 20a First power receiving device 20b Second power receiving device 20c Third power receiving device 21a First Power Receiving Section 21b Second power receiving section 21c Third Power Receiving Section 30a First Wireless Coupler 30b Second Wireless Coupler 30c Third Wireless Coupler 41 Transformer 42 Transformers 43 Gyrator 44 Transformers 45 Transformer 46 Transformer 141a Primary side compensation circuit for first coupler 141b Primary side compensation circuit for second coupler 141c Primary side compensation circuit for third coupler 142a Secondary side compensation circuit for first coupler 142b Secondary side compensation circuit for second coupler 142c Secondary side compensation circuit for third coupler

Claims

1. A power transmission device having a power receiving unit for receiving power to supply power to a load installed on a mobile body, and transmitting power to a power receiving device installed on the mobile body in a non-contact manner, High-frequency power supply and A power transmission unit that transmits power to the power receiving unit by forming a wireless coupler with the power receiving unit, comprising a plurality of power transmission units, each not simultaneously transmitting power to the same power receiving device, A distribution circuit for distributing the high-frequency power output from the high-frequency power supply to each of the multiple power transmission units, A transmission line is provided corresponding to each of the plurality of power transmission units and transmits the power distributed by the distribution circuit to the corresponding power transmission unit, A power transmission device characterized by comprising, for each of the plurality of power transmission units, a compensation circuit provided between the high-frequency power supply and the transmission line connected to the corresponding power transmission unit, for compensating for any deviation in reactance that may occur in the corresponding power transmission unit.

2. The aforementioned compensation circuit is A transmission line compensation circuit that compensates for the deviation in reactance in the transmission line connected to the corresponding power transmission unit, The wireless coupler comprises a coupler compensation circuit for compensating for the reactance deviation in the wireless coupler which can be formed by the corresponding power transmission unit, The power transmission device according to claim 1, characterized in that at least the compensation circuit for the transmission line is provided in the same housing as the distribution circuit.

3. A power transmission device that transmits power in a non-contact manner to a power receiving device provided on a mobile body, having a power receiving unit for receiving power to supply power to a load provided on the mobile body, High-frequency power supply and A power transmission unit that transmits power to the power receiving unit by forming a wireless coupler with the power receiving unit, comprising a plurality of power transmission units, each not simultaneously transmitting power to the same power receiving device, A distribution circuit for distributing the high-frequency power output from the high-frequency power supply to each of the multiple power transmission units, A transmission line is provided corresponding to each of the plurality of power transmission units and transmits the power distributed by the distribution circuit to the corresponding power transmission unit, Each of the aforementioned multiple power transmission units is provided with a compensation circuit that compensates for the deviation in reactance, The aforementioned compensation circuit is A transmission line compensation circuit that compensates for the deviation in reactance in the transmission line connected to the corresponding power transmission unit, The wireless coupler comprises a coupler compensation circuit for compensating for the reactance deviation in the wireless coupler which can be formed by the corresponding power transmission unit, A power transmission device characterized in that at least the compensation circuit for the transmission line is provided in the same enclosure as the distribution circuit.

4. The aforementioned coupler compensation circuit is The primary compensation circuit for the coupler provided on the power transmission side and the secondary compensation circuit for the coupler provided on the power receiving side compensate for the reactance deviation in the wireless coupler. The power transmission device according to claim 2 or 3, characterized in that the primary side compensation circuit for the coupler is located on the high-frequency power supply side of the compensation circuit for the transmission line and is provided in the same housing as the distribution circuit.

5. The aforementioned compensation circuit for the transmission line is The transmission line and the compensation circuit for the transmission line are configured to have the characteristics of a transformer or gyrator. The aforementioned coupler compensation circuit is The power transmission device according to claim 2 or 3, characterized in that the wireless coupler and the compensation circuit for the coupler are configured to have the characteristics of a transformer or a gyrator.

6. The power transmission device according to claim 1 or 3, characterized in that the transmission line is composed of a coaxial cable or a shielded cable.

7. The aforementioned distribution circuit is Each of the plurality of power transmission units is connected to a corresponding transmission line, and each unit is equipped with a switch for supplying power to the corresponding transmission line and for stopping the power supply. The aforementioned power transmission device is The power transmission device according to claim 1 or 3, further comprising a control unit that controls each switch based on whether or not to transmit power by the corresponding power transmission unit.

8. The power transmission device according to claim 1 or 3, characterized in that the high-frequency power supply and the distribution circuit are provided in the same housing.

9. A power receiving device provided on the mobile body, having a power receiving unit for receiving power to supply power to a load provided on the mobile body, A contactless power supply system comprising a power transmission device according to claim 1 or 3.

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