WO2022172691A1

WO2022172691A1 - Non-contact power receiving device and non-contact power feeding system

Info

Publication number: WO2022172691A1
Application number: PCT/JP2022/001302
Authority: WO
Inventors: 真義山本; 蒼大矢根
Original assignee: 国立大学法人東海国立大学機構
Priority date: 2021-02-10
Filing date: 2022-01-17
Publication date: 2022-08-18
Also published as: JPWO2022172691A1

Abstract

In this non-contact power receiving device 20, a power acquiring circuit 22 has: a coil 30 that is coupled by a magnetic field to a power feeding line 10 having one end connected to an AC power supply; and a first electrode 32 that is coupled by an electronic field to the power feeding line 10. The power acquiring circuit 22 acquires, through the coil 30 and the first electrode 32, a first AC power transmitted by traveling waves propagating on the power feeding line 10 from one end toward the other end and a second AC power transmitted by reflected waves propagating on the power feeding line 10 from the other end toward the one end. A power synthesis circuit 24 synthesizes the first AC power and the second AC power which are acquired by the power acquiring circuit 22 and outputs the synthesized power.

Description

Contactless power receiving device and contactless power supply system

Cross-reference to related applications

This application is based on Japanese Patent Application No. 2021-19679 filed on February 10, 2021, and claims the benefit of priority thereof. incorporated herein by reference.

The present disclosure relates to a contactless power receiving device and a contactless power supply system.

Conventionally, a contactless power supply system has been proposed that transmits electric power to a vehicle in a contactless manner and uses the transmitted electric power to drive the vehicle. For example, Patent Literature 1 discloses a non-contact power feeding system during travel, in which a plurality of coils are arranged along a travel path of a vehicle and coils for power transmission are switched according to the position of the vehicle.

JP 2020-48369 A

The present inventors have found that by supplying power to vehicles from transmission lines installed along roads, it becomes easier to install transmission lines over a wider area than the technique of arranging multiple coils, thereby reducing the cost of the contactless power supply system. I realized I could. However, when a reflected wave exists in the transmission line, there is a position where the current of the forward wave and the current of the reflected wave weaken each other. In addition, since the voltage of the traveling wave and the voltage of the reflected wave weaken each other at some positions in the transmission line, the received power decreases at those positions when power is supplied using an electric field. If a terminating resistor is provided in the transmission line to suppress reflected waves, power loss occurs due to the terminating resistor. Therefore, the inventors of the present invention have recognized that it is desirable to eliminate the need to suppress reflected waves while suppressing a decrease in received power.

One exemplary purpose of the present disclosure is to provide a contactless power receiving device and a contactless power supply system that can eliminate the need to suppress a reflected wave on a power supply line while suppressing a decrease in received power.

In order to solve the above problems, a non-contact power receiving device according to one aspect of the present disclosure includes a coil magnetically coupled to a power supply line having one end connected to an AC power supply, and a first electrode electrically coupled to the power supply line. , through the coil and the first electrode, a first alternating current power by a traveling wave propagating from one end to the other end of the power supply line, and a second power by a reflected wave propagating from the other end to the one end of the power supply line A power acquisition circuit that acquires AC power, and a power combining circuit that combines the first AC power and the second AC power acquired by the power acquisition circuit and outputs the combined power.

Another aspect of the present disclosure is a contactless power supply system. This contactless power supply system includes a power supply line to which an AC power supply is connected at one end, and a contactless power receiving device that receives power from the power supply line. The contactless power receiving device has a coil magnetically coupled to the power supply line and a first electrode electrically coupled to the power supply line, and propagates from one end of the power supply line to the other end via the coil and the first electrode. a power acquisition circuit for acquiring a first AC power by a traveling wave and a second AC power by a reflected wave propagating from the other end to one end of the feeder line; and the first AC power acquired by the power acquisition circuit and a power combining circuit that combines the second AC power and outputs the combined power.

It should be noted that any combination of the above constituent elements, and mutual replacement of the constituent elements and expressions of the present disclosure between methods, systems, etc. are also effective as aspects of the present disclosure.

According to the present disclosure, it is possible to provide a contactless power receiving device and a contactless power supply system that can eliminate the need to suppress reflected waves on a power supply line while suppressing a decrease in received power.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure for demonstrating schematic structure of the contactless electric power feeding system of 1st Embodiment. 2 is a perspective view of the feeder line of FIG. 1; FIG. 2 is an equivalent circuit diagram of the contactless power supply system of FIG. 1; FIG. FIG. 4(a) is a circuit diagram of a contactless power supply system of a comparative example, and FIG. 4(b) is an equivalent circuit diagram between the power transmission side circuit and the power reception side circuit of FIG. 4(a). It is an equivalent circuit diagram of the non-contact electric power supply system of the 1st modification of 1st Embodiment. It is an equivalent circuit diagram of the non-contact electric power supply system of the 2nd modification of 1st Embodiment. It is an equivalent circuit diagram of the non-contact electric power supply system of the 3rd modification of 1st Embodiment. It is an equivalent circuit diagram of the non-contact electric power supply system of the 4th modification of 1st Embodiment. It is a figure for demonstrating schematic structure of the non-contact electric power feeding system of the 5th modification of 1st Embodiment. It is a perspective view of the feeder line of the 6th modification of 1st Embodiment. FIG. 10 is an equivalent circuit diagram of the contactless power supply system of the second embodiment;

(First embodiment)
FIG. 1 is a diagram for explaining a schematic configuration of a contactless power supply system 1 according to the first embodiment. 2 is a perspective view of the feeder line 10 of FIG. 1. FIG. FIG. 3 is an equivalent circuit diagram of the contactless power supply system 1 of FIG.

The contactless power supply system 1 wirelessly powers a moving object 100 on a moving path such as a road. The contactless power supply system 1 can supply power even when the moving body 100 is stopped or moving. Mobile object 100 is, for example, a vehicle such as an automobile. A contactless power supply system 1 includes a power supply line 10 and a contactless power receiving device 20 .

An AC power supply 18 is connected to one end of the feeder line 10, and the other end of the feeder line 10 is open. The other end of the feeder line 10 may be short-circuited. The feeder line 10 includes a first conductor 12a and a second conductor 12b that are arranged in parallel along the road at a predetermined interval. AC power is supplied from an AC power supply 18 between one end of the first conductor 12a and one end of the second conductor 12b. Each of the first conductor 12a and the second conductor 12b is a plate-like elongated electrode, and can also be called a transmission electrode plate. The first conductor 12a and the second conductor 12b may be mesh electrodes. Although not shown, the feeder line 10 is covered with asphalt or the like and embedded in the road. The road is also called an electrified road.

The feeder line 10 functions as a transmission line for high-frequency power supplied from the AC power supply 18 . A voltage V and a current I are generated in the feed line 10 based on the characteristic impedance of the feed line 10, and an electric field E and a magnetic field H are generated. The power feeding line 10 feeds the non-contact power receiving device 20 with both the electric field E and the magnetic field H. FIG.

The frequency of the AC power supply 18 can be appropriately determined through experiments and simulations based on the transmission line characteristics of the feeder line 10 and the relationship between the wavelength and the size of the moving body 100, and is, for example, 1 MHz to 100 MHz. A higher frequency is preferable as the length of the feeder line 10 is shorter.

The contactless power receiving device 20 is mounted on the moving object 100 . The mobile object 100 moves on the power supply line 10 , and the non-contact power receiving device 20 receives power from the power supply line 10 while the mobile object 100 is stopped and moving. The received electric power is used to drive the wheels of the moving body 100 and the like.

As described above, since the other end of the feeder line 10 is open, the feeder line 10 has reflected waves in addition to traveling waves. The contactless power receiving device 20 uses the principle of a directional coupler to receive power from both traveling waves and reflected waves.

As shown in FIGS. 1 and 3, the contactless power receiving device 20 includes a power acquisition circuit 22, a power combining circuit 24, a smoothing circuit 26, and a load .

The power acquisition circuit 22 includes a coil 30 magnetically coupled to the first conductor 12a and the second conductor 12b, a first electrode 32 electrically coupled to the first conductor 12a, and a second electrode 34 electrically coupled to the second conductor 12b. have

The power acquisition circuit 22 acquires first AC power from a traveling wave propagating from one end of the power supply line 10 to the other end via the coil 30, the first electrode 32, and the second electrode 34, and supplies the power supply line with the power. A second AC power is obtained by a reflected wave propagating from the other end to the one end. One end of the coil 30 outputs the first AC power to the power combining circuit 24 and the other end of the coil 30 outputs the second AC power to the power combining circuit 24 .

The coil 30 is arranged on the bottom surface of the vehicle body 102 of the moving body 100 so that the coil surface is substantially parallel to the road. That is, the coil 30 is arranged so that the magnetic flux generated from the first conductor 12 a and the second conductor 12 b penetrates the coil 30 . Magnetic flux is maintained through the coil 30 when the moving body 100 is at rest and during movement. Coil 30 may include a magnetic core.

The first electrode 32 and the second electrode 34 are, for example, rectangular metal plates, and are arranged on the bottom surface of the vehicle body 102 of the moving body 100 such that they are substantially parallel to each other and each plate surface is substantially parallel to the road. It is When the moving body 100 stops and moves, the first electrode 32 faces the first conductor 12a and the second electrode 34 faces the second conductor 12b. Each area of the first electrode 32 and the second electrode 34 is, for example, equal. The first electrode 32 and the second electrode 34 are also referred to as receiving electrode plates.

The first electrode 32 is connected to the midpoint N1 of the coil 30. The midpoint N1 is the point where the inductance between the midpoint N1 and one end of the coil 30 and the inductance between the midpoint N1 and the other end of the coil 30 are equal. In FIG. 3, the portion between the midpoint N1 and one end of the coil 30 is represented as a first inductor L1, and the portion between the midpoint N1 and the other end of the coil 30 is represented as a second inductor L2.

The second electrode 34 is electrically connected to the vehicle body 102 of the mobile body 100 . The vehicle body 102 is made of a conductor such as metal, and functions as a common ground for the mobile body 100 . The common ground has a floating potential from the road, the first conductor 12a, and the second conductor 12b.

As shown in FIG. 3, the first inductor L1 of the coil 30 forms a transformer T1 together with the inductance component L10 of the magnetically coupled first conductor 12a. The second inductor L2 of the coil 30 forms a transformer T2 together with the inductance component L11 of the magnetically coupled second conductor 12b.

A first capacitor C1 is formed between the electric field-coupled first electrode 32 and the first conductor 12a. A second capacitor C2 is formed between the electric field coupled second electrode 34 and the second conductor 12b. The capacitances of the first capacitor C1 and the second capacitor C2 are the same. By providing the second electrode 34 separate from the vehicle body 102, the capacitance of the second capacitor C2 can be easily designed. Note that the second electrode 34 may not be provided separately from the vehicle body 102 . In this case, the vehicle body 102 functions as the second electrode 34, the vehicle body 102 is electrically coupled to the second conductor 12b, and the second capacitor C2 is formed between the vehicle body 102 and the second conductor 12b.

The first capacitor C1, the transformer T1 and the transformer T2 constitute a CM type, more specifically a CCM type directional coupler. Assuming a situation in which the voltages of the traveling wave and the reflected wave are in phase and the currents of the waves are in opposite phase, due to the configuration of the directional coupler, the received current I1 due to the traveling wave flows through the first conductor 12a and the first capacitor C1. , in the path of the first inductor L1. A received current I2 due to the reflected wave flows along the path of the first conductor 12a, the first capacitor C1, and the second inductor L2. As a result, the first alternating current power generated by the traveling wave can be output from one end of the coil 30 and the second alternating current power generated by the reflected wave can be output from the other end of the coil 30 .

The power combining circuit 24 is connected to both ends of the coil 30 , combines the first AC power and the second AC power acquired by the power acquisition circuit 22 , and outputs the combined power to the smoothing circuit 26 .

The power combining circuit 24 is a current doubler rectifier circuit and has a first rectifying element D1, a second rectifying element D2, a third inductor L3 and a fourth inductor L4. The first rectifying element D1 and the second rectifying element D2 are diodes. The first rectifying element D1 has an anode connected to a common ground and a cathode connected to one end of the coil 30 . The second rectifying element D2 has an anode connected to the common ground and a cathode connected to the other end of the coil 30 . One end of the third inductor L3 is connected to one end of the coil 30 . One end of the fourth inductor L4 is connected to the other end of the coil 30 . The other end of the third inductor L3 and the other end of the fourth inductor L4 are connected, and combined power is output from these connection nodes.

A DC cut capacitor is inserted between one end of the coil 30 and a connection node between the cathode of the first rectifying element D1 and one end of the third inductor L3, and the other end of the coil 30 and the second rectifying element A DC cut capacitor may be inserted between the cathode of D2 and a connection node with one end of the fourth inductor L4.

The smoothing circuit 26 smoothes the power output from the power combining circuit 24 and supplies the smoothed DC power to the load 28 . The smoothing circuit 26 has a smoothing capacitor C6 having one end supplied with the power output from the power combining circuit 24 and the other end connected to a common ground.

The power combining circuit 24 and the smoothing circuit 26 output a voltage based on the voltage of the second electrode 34, which is the voltage of the common ground.

DC power is supplied to one end of the load 28, and the other end of the load 28 is connected to a common ground. The load 28 includes, for example, a motor that generates driving force, an on-vehicle device, a storage battery, and the like.

The power receiving current I1 flowing through the first inductor L1 flows through the path of the third inductor L3, the smoothing capacitor C6, the common ground, the second capacitor C2, and the second conductor 12b. The first capacitor C1, the first inductor L1, and the second capacitor C2 form a series resonance circuit for receiving traveling waves.

The receiving current I2 flowing through the second inductor L2 flows along the path of the fourth inductor L4, smoothing capacitor C6, common ground, second capacitor C2, and second conductor 12b. The first capacitor C1, the second inductor L2, and the second capacitor C2 form a series resonance circuit for receiving reflected waves.

Resonant frequencies of the series resonant circuit for receiving the forward wave and the series resonant circuit for receiving the reflected wave are equal to the frequency of the AC power supply 18 and are included in a predetermined frequency band including the frequency of the AC power supply 18. . Due to the series resonance, the reactance can be reduced in each current path of the receiving current I1 and the receiving current I2, and the voltage drop due to the reactance can be suppressed. Therefore, wireless power supply can be performed with high transmission efficiency using both electric field and magnetic field.

Here, a non-contact power supply system of a comparative example that uses both the electric field and the magnetic field recognized by the present inventors to transmit power will be described. FIG. 4(a) is a circuit diagram of a contactless power supply system of a comparative example, and FIG. 4(b) is an equivalent circuit diagram between the power transmission side circuit 110 and the power reception side circuit 112 of FIG. 4(a). .

In the comparative example, a parallel circuit of mutual capacitance C40 and leakage inductance L40 shown in FIG. The mutual capacitance C40 is the sum of the capacitance of the capacitors C30 and C32 due to electric field coupling and the parasitic capacitance between the inductors L30 and L32 due to magnetic coupling. The leakage inductance L40 is the leakage inductance between the magnetically coupled inductors L30 and L32. Parallel resonance of the parallel circuit of the mutual capacitance C40 and the leakage inductance L40 causes the output voltage of the power transmission side circuit 110 to drop and is transmitted to the power reception side circuit 112 . As a result, transmission efficiency and transmission capacity are degraded.

On the other hand, in the embodiment, since series resonance occurs in the path from the first conductor 12a on the power transmission side to the second conductor 12b on the power transmission side via the non-contact power receiving device 20 as described above, leakage inductance exists. However, the decrease in transmission efficiency can be suppressed.

According to the embodiment, both the electric field and the magnetic field are used to receive the power of both the forward wave and the reflected wave. While suppressing, suppression of the reflected wave in the feeder line 10 can be made unnecessary.

Since it is not necessary to suppress the reflected wave from the other end of the feeder line 10, the other end of the feeder line 10 does not need to be terminated with a terminating resistor. Therefore, power loss due to the termination resistance can be eliminated. For example, if the termination resistor is 50Ω and the termination voltage is 300V, the power loss in the termination resistor is 1.8kW. Such relatively large power losses can be eliminated.

Also, when impedance mismatch occurs due to other vehicles on the road, reflected waves are generated, but there is no need to suppress these reflected waves. Therefore, even when there are multiple vehicles on the road, power can be supplied with high transmission efficiency regardless of the location. If it is necessary to suppress the generation of reflected waves from the vehicle, a technology that automatically controls the impedance of the terminating load according to the position of the vehicle is also conceivable. Complications, increased costs, and increased power loss can be suppressed.

(Modification of the first embodiment)
Various modifications of the contactless power supply system 1 are possible. The following description will focus on differences from the first embodiment.

FIG. 5 is an equivalent circuit diagram of the contactless power supply system 1 of the first modified example of the first embodiment. The contactless power receiving device 20 further includes a resonance capacitor C4 connected between one end and the other end of the coil 30 . The resonance capacitor C4 and the coil 30 form a parallel resonance circuit. The resonance frequency of the parallel resonance circuit is equivalent to the frequency of AC power supply 18 and is included in a predetermined frequency band including the frequency of AC power supply 18 . Parallel resonance can further reduce the reactance that could not be eliminated by series resonance. Therefore, the transmission efficiency can be made higher.

FIG. 6 is an equivalent circuit diagram of the contactless power supply system 1 of the second modification of the first embodiment. The configuration of the power combining circuit 24 is different. The power combining circuit 24 has a first rectifying element D1, a second rectifying element D2, a third rectifying element D3 and a fourth rectifying element D4. An anode of the third rectifying element D3 is connected to one end of the coil 30 . The anode of the fourth rectifying element D4 is connected to the other end of the coil 30. As shown in FIG. The cathode of the third rectifying element D3 and the cathode of the fourth rectifying element D4 are connected, and combined power is output from these connection nodes. The first rectifying device D1 and the third rectifying device D3 constitute a voltage doubler rectifying circuit, and the second rectifying device D2 and the fourth rectifying device D4 also constitute a voltage doubler rectifying circuit. Depending on the circuit design, power acquisition circuit 22 may function as a current source. In that case, by using a voltage doubler rectifier circuit, rectification and power combining can be performed more appropriately.

FIG. 7 is an equivalent circuit diagram of the contactless power supply system 1 of the third modification of the first embodiment. The power acquisition circuit 22 has an adjustment circuit 40 connected between the midpoint N1 of the coil 30 and the second electrode 34, which is a common ground. The adjustment circuit 40 adjusts at least one of the voltage and current at the midpoint N1. Thereby, the characteristics of the power acquisition circuit 22 can be adjusted. The adjustment circuit 40 has, for example, a resistor or adjustment capacitor connected between the midpoint N1 and common ground. A resistor and an adjusting capacitor may be connected in parallel between the midpoint N1 and the common ground.

When the adjustment circuit 40 has a resistance, the resistance value is set large so as to reduce the drop in the AC voltage at the midpoint N1. Basically, it is difficult to generate a DC bias voltage at the middle point N1, but if it is generated for some reason, the resistor can eliminate the DC bias voltage at the middle point N1. As a result, the DC bias voltage can be prevented from adversely affecting the operation of the power combiner circuit 24 .

When the adjustment circuit 40 has an adjustment capacitor, the AC voltage at the midpoint N1 can be adjusted by dividing the voltage of the first conductor 12a by the first capacitor C1 and the adjustment capacitor of the adjustment circuit 40. This makes it possible to improve the accuracy of separating the traveling wave and the reflected wave. It is also possible to adjust the resonance frequency.

FIG. 8 is an equivalent circuit diagram of the contactless power supply system 1 of the fourth modification of the first embodiment. The contactless power receiving device 20 further includes a detection section 42 and an adjustment section 44 . The detector 42 detects the current flowing through the coil 30 . The adjuster 44 adjusts the inductance of the coil 30 and the capacitance of the first capacitor C1 based on the current detected by the detector 42 . The adjuster 44 may also adjust the capacitance of the second capacitor C2.

The coil 30 is configured so that the number of turns, that is, the inductance, can be changed under the control of the adjustment unit 44 . A well-known technique can be used to change the number of turns. For example, the number of turns may be changed stepwise by switching between conduction and non-conduction of a switch element (not shown).

The first capacitor C1 is configured such that its capacitance can be changed under the control of the adjustment section 44. A well-known technique can be used to change the capacitance. For example, by switching between conduction and non-conduction of a switch element (not shown), the area of the first electrode 32 can be changed to change the capacitance stepwise.

The contactless power receiving device 20 is a power supply line designed to match a known power receiving device that receives power using only an electric field, or a known power receiving device that receives power using only a magnetic field. Power can also be received from the feeder line using both electric and magnetic fields. For example, when power is received from a power supply line for a power receiving apparatus that uses only an electric field, in the non-contact power receiving apparatus 20 designed according to the characteristic impedance of the power supply line 10 of the first embodiment, the current flowing through the coil 30 is 1 embodiment. Therefore, the adjustment unit 44 increases the inductance of the coil 30 by a first predetermined amount when the current detected by the detection unit 42 is equal to or less than the threshold value. Thereby, the current flowing through the coil 30 can be increased. Further, the adjustment unit 44 reduces the capacitance of the first capacitor C1 by a second predetermined amount when the current detected by the detection unit 42 is equal to or less than the threshold value. Thereby, the resonance frequency of the series resonance circuit, which changes by adjusting the inductance of the coil 30, can be made close to the frequency of the AC power supply 18. FIG. Therefore, the received power can be increased according to the characteristics of the existing power supply line.

FIG. 9 is a diagram for explaining a schematic configuration of the contactless power supply system 1 of the fifth modification of the first embodiment. The two first electrodes 32 and the two second electrodes 34 are metal parts inside the wheel 104 respectively. Also in this configuration, the first electrode 32 can be electrically coupled to the first conductor 12a, and the second electrode 34 can be electrically coupled to the second conductor 12b. In this case, the degree of freedom in configuration of the non-contact power receiving device 20 can be improved.

FIG. 10 is a perspective view of the feeder line 10 of the sixth modification of the first embodiment. The feeder line 10 is a transmission line including one first conductor 12a. One end of the AC power source 18 is connected to one end of the first conductor 12a, and the other end of the AC power source 18 is connected to a ground rod (not shown) to ground. A ground path plate may be provided under the first conductor 12a, and the other end of the AC power supply 18 may be connected to the ground path plate. A ground or ground routing plate serves as the second conductor. The other end of the first conductor 12a is open. The other end of the first conductor 12a may be shorted to ground or a ground routing plate.

FIG. 10 also shows the positional relationship between the coil 30 and the first electrode 32 with respect to the feeder line 10 . The coil 30 is arranged so that the coil surface is substantially perpendicular to the road and substantially parallel to the extending direction of the first conductor 12a. In other words, the coil 30 is arranged so that the magnetic flux generated from the first conductor 12a penetrates the coil 30 .

The first electrode 32 is arranged to face the first conductor 12a. The second electrode 34 may not be provided, or may be arranged to face the ground or a ground path plate (not shown). If the second electrode 34 is not provided, the vehicle body 102 functioning as the second electrode is electrically coupled to the ground or ground path plate functioning as the second conductor, and a second capacitor is provided between the vehicle body 102 and the ground or ground path plate. C2 is formed. The operation of this contactless power supply system 1 is similar to that of the first embodiment. In this modification, the flexibility of the configuration of the feeder line 10 can be improved. Installation of the feed line 10 can also be performed more easily.

It should be noted that the feeder line 10 may include three or more conductors. For example, in the case of three, a central conductor may be placed at the lane boundary on a two-lane road, and one conductor may be placed in each lane. Vehicles traveling in one lane receive power from the lane conductor and the center conductor. The central conductor is shared by vehicles traveling in each lane.

(Second embodiment)
In the second embodiment, the configuration of the power acquisition circuit 22 is different from that in the first embodiment. The following description will focus on differences from the first embodiment.

FIG. 11 is an equivalent circuit diagram of the contactless power supply system 1 of the second embodiment. The first electrode 32 has a third electrode 36 and a fourth electrode 38 . A third electrode 36 is electrically coupled to the first conductor 12 a and connected to one end of the coil 30 . A fourth electrode 38 is electrically coupled to the first conductor 12 a and connected to the other end of the coil 30 .

The third electrode 36 and the fourth electrode 38 are, for example, rectangular metal plates, and are arranged on the bottom surface of the vehicle body 102 of the moving body 100 so that each plate surface is substantially parallel to the road. The third electrode 36 and the fourth electrode 38 are maintained facing the first conductor 12a when the moving body 100 is stopped and during movement. Each area of the third electrode 36 and the fourth electrode 38 is, for example, equal.

A first capacitor C1 is formed between the electric field-coupled third electrode 36 and the first conductor 12a. A third capacitor C3 is formed between the electric field coupled fourth electrode 38 and the first conductor 12a. The capacitances of the first capacitor C1 and the third capacitor C3 are the same.

The first capacitor C1, the third capacitor C3, the transformer T1 and the transformer T2 constitute a CMC type directional coupler. Assuming a situation in which the voltages of the traveling wave and the reflected wave are in phase and the currents of the waves are in opposite phase, due to the configuration of the directional coupler, the received current I1 due to the traveling wave is transferred to the first conductor 12a and the third capacitor C3. , the second inductor L2 and the first inductor L1, and the current flowing through the first conductor 12a and the first capacitor C1. The received current I2 due to the reflected wave is the sum of the current flowing through the path of the first conductor 12a and the third capacitor C3 and the current flowing through the path of the first conductor 12a, the first capacitor C1, the first inductor L1, and the second inductor L2. It is harmony. As a result, the first alternating current power generated by the traveling wave can be output from one end of the coil 30 and the second alternating current power generated by the reflected wave can be output from the other end of the coil 30 . A CMC-type directional coupler can separate the traveling wave and the reflected wave more clearly.

The power receiving current I1 flows through the power combining circuit 24, the smoothing capacitor C6, the common ground, the second capacitor C2, and the second conductor 12b.

The power receiving current I2 flows through the power combining circuit 24, the smoothing capacitor C6, the common ground, the second capacitor C2, and the second conductor 12b.

The inductance of the coil 30 and the capacitances of the first capacitor C1, the third capacitor C3 and the second capacitor C2 are set so that the reactance is reduced by resonance in the current path from the first conductor 12a to the second conductor 12b. good too. Thereby, voltage drop due to reactance can be suppressed. Therefore, wireless power supply can be performed with high transmission efficiency using both electric field and magnetic field.

The present disclosure has been described above based on the embodiment. It should be understood by those skilled in the art that the present disclosure is not limited to the above embodiments, and that various design changes and modifications are possible, and that such modifications are within the scope of the present disclosure. It is about

For example, any two or more of the first to sixth modifications of the first embodiment may be combined. A new embodiment resulting from combination has the effects of each of the combined embodiments. When combining the first modification and the fourth modification, when changing the inductance of the coil 30, the adjustment unit 44 may also adjust the capacitance of the resonance capacitor C4 so that the parallel resonance frequency approaches the frequency of the AC power supply 18. good.

Each of the first, second, fourth to sixth modifications of the first embodiment may be combined with the second embodiment. Any two or more of the first, second, fourth to sixth modifications may be combined with the second embodiment. A new embodiment resulting from combination has the effects of each of the combined embodiments. When combining the fourth modification with the second embodiment, the adjustment unit 44 adjusts the inductance of the coil 30, the capacitance of the first capacitor C1, and the third capacitor C3 based on the current detected by the detection unit 42. may be adjusted.

In addition to automobiles, the non-contact power supply system 1 includes, for example, railways, electric aircraft, playground equipment such as roller coasters in amusement parks, cleaning robots, delivery robots, guide robots, etc., self-propelled transport equipment in factory premises, and models. It can be applied to toys such as automobiles. When applied to an electric aircraft, power can be supplied while taxiing.

In the embodiment, an example in which the power supply line 10 is arranged on the road and the non-contact power receiving device 20 is mounted on the mobile object 100 has been described, but the present invention is not limited to this. The power supply line 10 may be arranged on a charging stand, and the non-contact power receiving device 20 may be mounted on a mobile device such as a smart phone. In this case, the portable device can be charged by placing it at any position on the power supply line 10 of the charging stand.

A summary of one aspect of the present disclosure is as follows. A non-contact power receiving device according to one aspect of the present disclosure includes a coil magnetically coupled to a power supply line having one end connected to an AC power supply, and a first electrode electrically coupled to the power supply line, wherein the coil and the first a first alternating current power by a traveling wave propagating from one end of the power supply line to the other end, and a second alternating current power by a reflected wave propagating from the other end to the one end of the power feeding line through the electrodes; and a power combining circuit for combining the first AC power and the second AC power acquired by the power acquiring circuit and outputting the combined power.
According to this aspect, it is possible to eliminate the need to suppress reflected waves in the feeder line while suppressing a decrease in received power.

The feed line includes a first conductor and a second conductor arranged in parallel, the first electrode is electrically coupled to the first conductor and connected to a midpoint of the coil, and one end of the coil is: The first AC power is output, the other end of the coil outputs the second AC power, the power acquisition circuit further includes a second electrode that is electrically coupled to the second conductor, and the power combining The circuit may output a voltage that is referenced to the voltage of said second electrode. In this case, a CM type directional coupler can be constructed.

A first capacitor formed between the first electrode and the first conductor, a portion between the midpoint of the coil and one end or the other end, and between the second electrode and the second conductor may form a series resonant circuit. In this case, the series resonance can reduce the reactance of the current path from the first conductor to the second conductor via the coil.

The non-contact power receiving device includes a detection unit that detects current flowing through the coil, and an adjustment unit that adjusts the inductance of the coil and the capacitance of the first capacitor based on the current detected by the detection unit. , may be further provided. In this case, the received power can be increased according to the characteristics of the power supply line.

The power acquisition circuit may further include an adjustment circuit that adjusts at least one of voltage and current at the midpoint of the coil. In this case, the characteristics of the power acquisition circuit can be adjusted.

The power supply line includes a first conductor and a second conductor arranged in parallel, one end of the coil outputs the first AC power, and the other end of the coil outputs the second AC power. , the power acquisition circuit may further comprise a second electrode electrically coupled to the second conductor, and the power combining circuit may output a voltage referenced to the voltage of the second electrode. The first electrode includes a third electrode electrically coupled to the first conductor and connected to one end of the coil, and a fourth electrode electrically coupled to the first conductor and connected to the other end of the coil. , may have In this case, a CMC type directional coupler can be constructed, and the traveling wave and the reflected wave can be separated more clearly.

The non-contact power receiving device includes a detection unit that detects a current flowing through the coil, and based on the current detected by the detection unit, a current is detected between the inductance of the coil and between the third electrode and the first conductor. It may further comprise an adjusting unit that adjusts the capacitance of the formed first capacitor and the capacitance of the third capacitor formed between the fourth electrode and the first conductor. In this case, the received power can be increased according to the characteristics of the power supply line.

The contactless power receiving device may further include a resonance capacitor connected between one end and the other end of the coil. In this case, parallel resonance by the coil and the resonance capacitor can further reduce the reactance.

A contactless power supply system according to one aspect of the present disclosure includes a power supply line having one end connected to an AC power supply, and a contactless power receiving device that receives power from the power supply line. The non-contact power receiving device has a coil that is magnetically coupled to the power supply line and a first electrode that is electrically coupled to the power supply line, and the power supply line is connected to the power supply line via the first coil and the first electrode. a power acquisition circuit for acquiring first AC power by a traveling wave propagating from one end to the other end and acquiring second AC power by a reflected wave propagating from the other end to the one end of the feeder line; and a power combining circuit that combines the first AC power and the second AC power acquired by the acquisition circuit and outputs the combined power. According to this aspect, it is possible to eliminate the need to suppress reflected waves in the feeder line while suppressing a decrease in received power.

The other end of the feeder line may be open or short-circuited. In this case, power loss can be reduced compared to the case where a terminating resistor for impedance matching is connected to the feeder line.

The present disclosure can be used for contactless power receiving devices and contactless power supply systems.

REFERENCE SIGNS LIST 1 non-contact power supply system 10 power supply line 12a first conductor 12b second conductor 18 AC power supply 20 non-contact power receiving device 22 power acquisition circuit 24 power combining circuit 30 Coil 32 First electrode 34 Second electrode 36 Third electrode 38 Fourth electrode 42 Detector 44 Adjuster C1 First capacitor C2 Second capacitor C3 Third capacitor, C4... resonance capacitor, N1... middle point.

Claims

A coil magnetically coupled to a feeder line having one end connected to an AC power supply, and a first electrode electrically coupled to the feeder line, wherein the feeder line is connected from one end via the coil and the first electrode. a power acquisition circuit for acquiring a first AC power by a traveling wave propagating toward the other end and a second AC power by a reflected wave propagating from the other end toward one end of the feeder line;
a power combiner circuit for combining the first AC power and the second AC power acquired by the power acquisition circuit and outputting the combined power;
A contactless power receiving device comprising:
The feed line includes a first conductor and a second conductor arranged in parallel,
the first electrode is electrically coupled to the first conductor and connected to a midpoint of the coil;
one end of the coil outputs the first AC power,
the other end of the coil outputs the second AC power,
the power acquisition circuit further comprising a second electrode that is electrically coupled to the second conductor;
The power combining circuit outputs a voltage based on the voltage of the second electrode.
The non-contact power receiving device according to claim 1, characterized by:
A first capacitor formed between the first electrode and the first conductor, a portion between the midpoint of the coil and one end or the other end, and between the second electrode and the second conductor The second capacitor formed in constitutes a series resonant circuit,
The non-contact power receiving device according to claim 2, characterized in that:
a detection unit that detects the current flowing through the coil;
an adjustment unit that adjusts the inductance of the coil and the capacitance of the first capacitor based on the current detected by the detection unit;
The contactless power receiving device according to claim 3, further comprising:
The power acquisition circuit further comprises an adjustment circuit that adjusts at least one of voltage and current at the midpoint of the coil.
The non-contact power receiving device according to any one of claims 2 to 4, characterized in that:
The feed line includes a first conductor and a second conductor arranged in parallel,
one end of the coil outputs the first AC power,
the other end of the coil outputs the second AC power,
the power acquisition circuit further comprising a second electrode that is electrically coupled to the second conductor;
The power combining circuit outputs a voltage based on the voltage of the second electrode,
The first electrode is
a third electrode electrically coupled to the first conductor and connected to one end of the coil;
a fourth electrode electrically coupled to the first conductor and connected to the other end of the coil;
The contactless power receiving device according to claim 1, characterized by comprising:
a detection unit that detects the current flowing through the coil;
based on the current detected by the detection unit, the inductance of the coil, the capacitance of a first capacitor formed between the third electrode and the first conductor, the fourth electrode and the first conductor; an adjustment unit that adjusts the capacitance of a third capacitor formed between
The contactless power receiving device according to claim 6, further comprising:
further comprising a resonant capacitor connected between one end and the other end of the coil;
The contactless power receiving device according to any one of claims 2 to 7, characterized by:
a feeder line having one end connected to an AC power supply;
a non-contact power receiving device that receives power from the power supply line;
with
The contactless power receiving device
It has a coil magnetically coupled to the power supply line and a first electrode electrically coupled to the power supply line, and propagates from one end to the other end of the power supply line via the coil and the first electrode. a power acquisition circuit for acquiring a first AC power by a traveling wave and a second AC power by a reflected wave propagating from the other end of the feeder line to one end thereof;
a power combiner circuit for combining the first AC power and the second AC power acquired by the power acquisition circuit and outputting the combined power;
A contactless power supply system comprising:
The other end of the feed line is open or short-circuited,
The contactless power supply system according to claim 9, characterized in that: