WO2016017022A1

WO2016017022A1 - Wireless power transmission system and wind power generator

Info

Publication number: WO2016017022A1
Application number: PCT/JP2014/070300
Authority: WO
Inventors: 清人松島; 秋山　仁; 市川　勝英
Original assignee: 株式会社日立製作所
Priority date: 2014-08-01
Filing date: 2014-08-01
Publication date: 2016-02-04

Abstract

The purpose of the present invention is to provide a wireless power transmission system that allows a wide-range wireless power transmission and a wind power generator in which the wireless power transmission system is mounted. Provided is a wireless power transmission system including a power source, a power transmitting unit that is connected to the power source and wirelessly transmits power from the power source at a predetermined resonant frequency, a plurality of power relaying units that wirelessly receive power and wirelessly transmit the power to another device, and a plurality of power receiving units that wirelessly receive the power wirelessly transmitted by the plurality of power relaying units. One of the plurality of power relaying units receives the power transmitted from the power transmitting unit and sequentially transmits the power to others of the plurality of power relaying units that are subsequent to the one of the plurality of power relaying units.

Description

Wireless power transmission system and wind power generator

The present invention relates to a wireless power transmission system and a wind power generator.

As background art in this technical field, there are JP 2013-85322 A (Patent Document 1) and JP 2013-198327 A (Patent Document 2). The gazette of Patent Literature 1 states that “the vehicular power transmission apparatus 102 includes one wireless power transmission unit 110 and one or more wireless power reception units 120, from one wireless power transmission unit 110. It is possible to transmit power wirelessly to a plurality of wireless power receiving units 120. The wireless power receiving unit 120 can adjust the resonance frequency f2 on the power receiving side, and the secondary resonance coil 122 and the power receiving unit. The power receiving side resonance frequency adjusting unit 124 is provided for adjusting the circuit constant of the side capacitor 123. Similarly, the wireless power transmission unit 110 can also adjust the resonance frequency f1 on the power transmission side. ing. Further, the gazette of Patent Document 2 states that “a power transmission device as one aspect of the present invention is a power transmission device that transmits power supplied from a power source to one or more power reception devices, and includes a power allocation processing unit, The power allocation processing unit allocates, to the power receiving device, a resource for transmitting power to the power receiving device based on the required power of the power receiving device, and allocates the resource to the power receiving device. A surplus resource that is a resource that remains after is allocated to a power receiving device selected from the power receiving device based on a power transmission characteristic of the power receiving device, wherein the power transmission unit uses the resource allocated to the power receiving device, The power is transmitted to the power receiving apparatus ”(see the summary for each).

JP 2013-85322 A JP 2013-198327 A

Patent Document 1 describes the configuration of a wireless power transmission system capable of wireless power transmission from one power transmission device to a plurality of power reception devices. However, the number and arrangement of power reception devices are within a range where power can be transmitted from one power transmission device. There are limited problems. For example, when the power receiving device is located far from one power transmission device and exceeds the power transmission possible range of the power transmission device, power transmission is not possible. In this case, as described in Patent Document 2, it is possible to cope by providing a plurality of power transmission devices, but there is a problem that the cost is increased.

Also, when configuring a system for transmitting power to a remote power receiving device using the above technique, it is necessary to provide a wired power line from the power source to each power transmitting device. Since the voltage level of low-frequency noise caused by induced lightning increases in proportion to the length of the power supply line, the overpower input to the low-voltage drive device located near the power transmission / reception device in the system that supplies power farther away Will increase the risk of failure.

Therefore, an object of the present invention is to provide a wireless power transmission system capable of wireless power transmission over a wide range and a wind power generator equipped with the wireless power transmission system.

In order to solve the above problems, for example, the configuration described in the claims is adopted. As an example, a wireless power transmission system includes a power source, a power transmission unit that is connected to the power source, and wirelessly transmits power obtained from the power source at a predetermined resonance frequency, A plurality of power relay units that wirelessly transmit to the device, and a plurality of power reception units that wirelessly receive the power wirelessly transmitted by the power relay unit, the power transmitted from the power transmission unit of the power relay unit One is received, and the power relay unit sequentially transmits power to the subsequent power relay unit to transmit power.

According to the present invention, it is possible to provide a wireless power transmission system that enables a wide range of wireless power transmission.

It is a figure which shows the 1st structure of the wireless power transmission system in a 1st Example. It is a figure which shows the 2nd structure of the wireless power transmission system in a 1st Example. It is a figure which shows the 3rd structure of the wireless power transmission system in a 1st Example. It is a figure which shows the specific example of the 3rd structure of the wireless power transmission system in a 1st Example. It is a figure which shows the structure of the wireless power transmission system in a 2nd Example. It is a figure which shows the specific example of the wireless power transmission system in a 2nd Example. It is a figure which shows the specific example of the wireless power transmission system in a 3rd Example. It is a figure of the wind power generator which applied the wireless power transmission system.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

The configuration of the first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a diagram illustrating a first configuration of the wireless power transmission system according to the first embodiment.

As shown in FIG. 1, the wireless power transmission system 1 includes a power source 100, a wireless power transmission unit 101, and a plurality of wireless power relay units 110. Specifically, a wireless power transmission unit 101 that transmits wireless power supply power at a predetermined resonance frequency is connected to the power supply 100, and the wireless power transmission unit 101 sequentially relays the wireless power supply power to the subsequent stage using an electric field or a magnetic field as a medium. Wirelessly connected to the first wireless power relay unit 110-1.

Further, the first wireless power relay unit 110-1 is wirelessly connected to the second wireless power relay unit 110-2 that is further from the wireless power transmission unit 101 than the first wireless power relay unit 110-1. The second wireless power relay unit 110-2 is wirelessly connected to a third wireless power relay unit 110-3 located farther from the wireless power relay unit. Although an example in which three wireless power relay units 110 are connected is shown here, this number is not limited to the present embodiment.

These wireless power relay units 110 each include a reception relay antenna 111 and a transmission relay antenna 112, and the reception relay antenna 111 and the transmission relay antenna 112 are connected by a wired transmission path.

1, the wireless power transmission system 1 includes a plurality of wireless power receiving units 120 that receive wireless power and generate circuit driving power. The wireless power receiving unit 120 controls the amount of power received by changing the resonance frequency of the power receiving antenna 121, the load 122 simulating the size of the circuit load that operates by receiving power from the power receiving antenna 121, and the power receiving antenna 121. The reception power control unit 130 is configured.

Hereinafter, the operation of the wireless power transmission system of this embodiment will be described. Based on the power of the power supply 100, the wireless power transmitting unit 101 outputs an electric field or magnetic field having a predetermined resonance frequency to the reception relay antenna 111-1 of the adjacent first wireless power relay unit 110-1. The reception relay antenna 111-1 of the wireless power relay unit 110 close to the wireless power transmission unit 101 receives this electric field or magnetic field and converts it into power, and this power is transmitted to the transmission relay antenna 112-1 connected through a wired transmission path. To transmit.

Then, the transmission relay antenna 112-1 wirelessly transmits the power received from the reception relay antenna 111-1 to the reception relay antenna 111-2 of the second wireless power relay unit 110-2 in the subsequent stage that combines the electric power or the magnetic field as a medium. It is supposed to be transmitted at. Thereafter, power is transmitted from the second wireless power relay unit 110-2 to the third wireless power relay unit 110-3 in the same manner as described above.
Here, it is desirable that the reception relay antenna 111 and the transmission relay antenna 112 be adjusted in the shape of the antenna, the capacitor capacity that determines the resonance frequency, the matching circuit, and the like so that the wireless power having the predetermined resonance frequency can be transmitted with the maximum efficiency.

By exchanging wireless power transmission between the wireless power relay units 110, the power of the power source 100 can be transmitted to the wireless power relay unit 110 that is distant from the wireless power transmission unit 101, and a wide range of wireless power transmission is possible. In addition, wireless power transmission between the wireless power transmission unit 101 and the reception relay antenna 111 and between the transmission relay antenna 112 and the reception relay antenna 111 can be transmitted with particularly high efficiency when close to the transmission and reception antennas such as electromagnetic induction, magnetic resonance, and electric field resonance. Although a system is desirable, other wireless power transmission systems may be adopted.

Next, the power transmission operation to the plurality of wireless power receiving units 120 in the wireless power transmission system 1 will be described. In FIG. 1, three wireless power receiving units 120 are arranged in the wireless power transmission system 1. The wireless power receiving unit 120 is an independent device that includes a circuit that receives an electric field or a magnetic field output from the transmission relay antenna 112, converts it into circuit driving power and uses it as a power source, and a circuit that realizes a predetermined function.

As an example, the power transmission operation of the first wireless power relay unit 110-1 and the first wireless power receiving unit 120 will be described. The transmission relay antenna 112-1 of the first wireless power relay unit 110-1 described above transmits power wirelessly to the second wireless power relay unit behind and transmits the power to the first wireless power reception unit 120-1. Even power is transmitted wirelessly.

The first wireless power receiving unit 120-1 receives the electric field or magnetic field output from the transmission relay antenna 112-1 by the power receiving antenna 121-1, rectifies it, and applies it to the load 122-1 as circuit drive power. For the wireless power transmission between the transmission relay antenna 112-1 and the power receiving antenna 121-1, a method capable of transmitting with high efficiency regardless of the distance between both antennas such as magnetic resonance and electric field resonance is desirable, but other wireless power transmission methods are adopted. You may do it. However, the wireless power transmission method is limited to a method using a common medium for wireless power transmission between the transmission relay antenna 112 and the reception relay antenna 111.

In addition, the appropriate range of the installation position of the wireless power receiving unit 120 differs depending on the wireless power transmission method between the transmission relay antenna 112 and the power receiving antenna 121. For example, when the electromagnetic induction method is adopted, the power transmission coil that is the transmission relay antenna 110 and the power reception coil that is the power reception antenna 121 are disposed at positions that are almost directly opposed to each other, and the distance between both antennas is within several centimeters. Is desirable.

Even when adopting a method such as magnetic resonance that is resistant to displacement of the positions of both coils, it is desirable to have the power transmitting and receiving coils face each other so that they can be transmitted with high efficiency. The power receiving coil may be arranged at an arbitrary position as long as it does not interfere with the power transmitting coil.

Similar to the above operation, the second wireless power relay unit 110-2 transmits wireless power to the second wireless power receiving unit 120-2, and the third wireless power relay unit 110-3 transmits the third wireless power receiving unit 120-3. Wireless power transmission.

However, according to the above operation, the wireless power relay unit 110 and the wireless power receiving unit 120 connected to the wireless power relay unit 110 are coupled in series mainly with the wireless power transmitting unit 101 as a base point. However, there is a problem that excessive power is received.

Therefore, each of the wireless power receiving units 120 is provided with a reception power control unit 130 so that the resonance frequency of the power receiving antenna 121 can be adjusted. The received power control unit 130 adjusts the resonance frequency of the power receiving antenna 121 according to the number of other wireless power receiving units 120 coupled to the wireless power relay unit 110 between the wireless power transmitting unit 101 and the target wireless power receiving unit 120.

Specifically, the reception power control unit 130 is configured so that the antenna resonance frequency deviates from the specified resonance frequency as much as the power reception antenna 121 of the wireless power reception unit 120 coupled to the wireless power relay unit 110 close to the wireless power transmission unit 101. The capacitor capacity and the like that determine the shape and resonance frequency are adjusted.

Further, as shown in FIG. 2, the received power control unit 130 includes a power receiving antenna 121 and a load 122 so that the impedance of the load 122 of the wireless power receiving unit 120 coupled to the wireless power relay unit 110 close to the wireless power transmitting unit 101 increases. A matching circuit (not shown) may be adjusted.

Also, in FIG. 3, a magnetic resonance method or an electric field resonance method is used for wireless power transmission between the transmission relay antenna 112 and the power reception antenna 121 included in the wireless power reception unit 120, and resonance that resonates with the transmission relay antenna 112 as a pair. A configuration example in which the element 140 is disposed between both antennas is shown.

In this example, the reception power control unit 130 changes the impedance and arrangement position of the resonance element 140 between the wireless power relay unit 110 and the power receiving antenna 121 close to the wireless power transmission unit 101 and changes the transmission relay. You may adjust so that the resonant frequency of the antenna 112 may remove | deviate. According to this configuration, it is also possible to employ different wireless power transmission methods for the wireless power relay unit 110 and the wireless power receiving unit 120 in the subsequent stage, where one is an electromagnetic induction method and the other is a magnetic resonance method.

In any of the cases in FIGS. 1 to 3, the reception power control unit 130 is described independently of the power receiving antenna 121 and the load 122 so that it can be adjusted after the product is installed. The power receiving antenna 121 and the load 122 may be included. When the wireless power transmission loss between the transmission relay antenna 112 and the power receiving antenna 121 is large, or when a plurality of power receiving antennas 121 are coupled to one transmission relay antenna 110, the wireless power receiving unit is not limited to the above. It adjusts so that the electric power distributed to 120 may become electric power corresponding to each required amount.

From the above, in a wireless power transmission system, power can be transmitted wirelessly even at a position away from the power source.

Here, a specific product example to which the wireless power transmission system according to the present embodiment is applied will be described with reference to FIGS. FIG. 8 is a diagram of a wind power generator to which the wireless power transmission system of the present embodiment is applied. FIG. 4 is a configuration showing details of the wireless power transmission system of the wind power generator, and wireless communication between wireless power relay units. FIG. 4 is a diagram in which power transmission is an electromagnetic induction method and wireless power transmission between a wireless power relay unit and a wireless power receiving unit is a magnetic resonance method.

Wind power generators have a high risk of blade and tower damage due to natural disasters such as lightning, typhoons, and earthquakes, and there is a problem of reduced operating rate due to repairs and parts replacement work. Therefore, sensors that detect the state of the structure are installed at various locations, and structural monitoring (SHM: Structural Health Monitoring) and state monitoring (Condition Monitoring) are performed to predict and quickly detect the failure location and efficiently perform maintenance work. However, there is a demand for reducing downtime.

When attaching sensors to a huge structure exceeding several tens of meters, such as a blade of a wind power generator, the sensors are arranged on the surface of the structure at intervals of several meters, and power is supplied using small batteries that are provided independently. In general, power supplied from the nacelle is supplied in a wired manner from the root of the blade to the tip.

However, the former method is applied to a condition monitoring system that requires data acquisition and transmission to a data collection device several tens of times per second because the small battery driving time is less than the regular maintenance frequency of one year. Have difficulty.

Also, in the latter method, when a lightning strike to the lightning receptor provided at the blade tip or the like, an excessive current is generated with respect to the power supply line due to induction from the lead wire passing through the blade toward the grounding electrode from the receptor. Sensors may break down.

For the above reasons, wireless power transmission from the power transmission unit is suitable as a method for supplying power to sensors attached to a huge structure, and in particular, wireless power transmission of this embodiment that enables power transmission from the power transmission unit to a distant place. The system configuration is suitable for mounting on huge structures.

FIG. 8 shows an example in which the wireless power transmission system of this embodiment is mounted on a wind power generator, and in particular, the wireless power transmission system is mounted on a blade that is an observation object 160 of the wind power generator. The detailed configuration of the wireless power transmission system mounted on this blade is shown in FIG.

4, in addition to the configuration shown in FIG. 3, a lightning receptor 150 for preventing damage to the structure due to a lightning strike, and a grounding connected from the lightning receptor 150 routed near the wireless power relay unit 110 to the ground electrode. A line 151 and an observation symmetry object 160 to be observed such as a distortion amount are included.

The received power control unit 130 is included in at least one of the power receiving antenna 121, the load 122, and the resonance element 140, and is not illustrated here. The resonance element 140 is disposed between the transmission relay antenna 112 and the power receiving antenna 121 included in the wireless power receiving unit 120.

Then, a magnetic resonance method capable of high-efficiency transmission is adopted between the transmission relay antenna 112 and the power receiving antenna 121, which may occur due to deformation of the observation object 160, even if the installation position between the two antennas is shifted. An electromagnetic induction method is employed between the reception relay antennas 111, which hardly causes resonance frequency fluctuations due to the proximity of both antennas.

If a magnetic resonance method with a specified frequency of several MHz or more is adopted for wireless power transmission between the transmission relay antenna 112 and the power receiving antenna 121, a voltage of about 100 kHz is attenuated by 30 dB or more. Therefore, the fluctuation of the power supply voltage of the circuit can be reduced to a level that can be dealt with by a normal protection circuit, even when there is a lightning strike.

Therefore, in the sensor system mounted on the wind power generator, if the configuration exemplified above is used, it is possible to supply electric power corresponding to the required amount to each sensor arranged far from the power transmission unit, It is also possible to have lightning resistance, which was a problem in conventional sensor systems.

Next, the second embodiment will be described with reference to FIGS. Since the present embodiment shows an alternative configuration of the wireless power relay unit 110 of FIGS. 1 to 3, the description overlapping with the first embodiment will be omitted.

In FIG. 5, a wireless power relay unit 110-1 receives wireless power transmitted from the wireless power transmitting unit 101 side, and relays and transmits most of the wireless power to the subsequent stage, and a wireless power receiving unit 120-1 The power receiving antenna 121-1 includes a power feeding antenna 114-1 that transmits a part of the power received by the transmission / reception relay antenna 113-1, and the two antennas are connected by wire.

In this figure, the case where the received power control unit 123 adjusts the resonance frequency of the power receiving antenna 121 is shown, but the resonance inserted between the load 122 or the power feeding antenna 114 and the power receiving antenna 121 is the same as in another configuration in the first embodiment. It is good also as a structure which adjusts an element.

The wireless power transmitting unit 101 outputs an electric field or magnetic field having a predetermined resonance frequency to the adjacent reception relay antenna 113-1 based on the power of the power supply 100. The transmission / reception relay antenna 113-1 of the wireless power relay unit 110-1 adjacent to the wireless power transmission unit 101 receives this electric field or magnetic field, and re-radiates most of it to the subsequent transmission / reception relay antenna 113-2.

It is desirable that the transmission / reception relay antenna 113 is adjusted to adjust the shape of the antenna, the capacitor capacity that determines the resonance frequency, and the matching circuit so that the wireless power at the resonance frequency can be transmitted with the maximum efficiency.

By transmitting and receiving wireless power between the transmission / reception relay antennas 113 included in the wireless power relay unit 110, the power of the power supply 100 output through the wireless power transmission unit 101 is transmitted from the wireless power transmission unit 101 to the wireless power relay unit 110 at a distant position. can do. The wireless power transmission between the wireless power transmission unit 101, the transmission / reception relay antenna 113, and the transmission / reception relay antenna 113 is preferably a magnetic resonance or electric field resonance method capable of transmitting several meters.

A part of the power received by the transmission / reception relay antenna 113-1 is output from the feeding antenna 114-1 to the power receiving antenna 121-1 of the wireless power receiving unit 120. Since the ratio of the power output to the wireless power receiving unit 120-1 and the power output to the subsequent wireless power relay unit 110-2 is determined by the ratio of the impedance coupled and connected to the antenna, each load The reception power control unit 130 adjusts each unit so as to secure the required reception power amount of 122 and not to cause excessive input.

The wireless power transmission between the power feeding antenna 114 and the power receiving antenna 121 is preferably a method capable of transmitting with high efficiency regardless of the distance between both antennas, such as magnetic resonance or electric field resonance, but other wireless power transmission methods may be adopted.

The appropriate range of the installation position of the wireless power receiving unit 120 varies depending on the wireless power transmission method between the power feeding antenna 114 and the power receiving antenna 121. For example, when the electromagnetic induction method is employed, the power transmission coil that is the power feeding antenna 114 and the power reception coil that is the power reception antenna 121 are disposed at positions that are almost directly opposed to each other, and the distance between both antennas is within several centimeters.

Further, a magnetic resonance method or an electric field resonance method is used for wireless power transmission between the power feeding antenna 114 and the power receiving antenna 121 included in the wireless power receiving unit 120, and a resonance element that resonates with the power feeding antenna 114 as a pair is disposed between both antennas. You may do it.

FIG. 6 shows an example in which the configuration of FIG. 5 in which wireless power transmission between the power feeding antenna 114 and the power receiving antenna 121 is realized by a magnetic resonance method is applied to a wind power generator in the same manner as in the description of the first embodiment. Between the transmission / reception relay antenna 113 that relays wireless power by the magnetic resonance method, a relay coil 170 that resonates at a predetermined frequency may be inserted between both antennas in order to increase power transmission efficiency.

According to this configuration, the cable deletion between the reception relay antenna 111 and the transmission relay antenna 112 and the application of the magnetic resonance method of the specified frequency between the transmission and reception relay antenna 113 compared to the configuration of the first embodiment, It is possible to further reduce the power supply voltage fluctuation during lightning strike by 10 dB or more.

From the above, it is possible to provide a wireless power transmission system that realizes a wide range of wireless power transmission.

Also, the wireless power transmission system of the present embodiment can be mounted on a wind power generator as in the first embodiment. As a result, in the sensor system mounted on the wind power generator, it is possible to supply power corresponding to the required amount to each of the sensors arranged far from the power transmission unit, and this is a problem in the conventional sensor system. It also becomes possible to have lightning resistance.

Next, a third embodiment will be described with reference to FIG. Since the present embodiment shows an arrangement example of the wireless power relay unit 110 of FIGS. 1 to 3 and 5, description overlapping with that of the first embodiment is omitted.

In the first embodiment and the second embodiment, the configuration in which power is transmitted in one direction with the wireless power transmission unit 101 as a base point is mainly shown. In power transmission to the network, loss due to an increase in transmission distance may occur, and transmission efficiency may decrease.

FIG. 7 shows a configuration in which power is transmitted in two directions with the wireless power transmission unit 101 as a base point. Two reception relay antennas 111 are arranged in the wireless power transmission unit 101, and the power transmission unit distributes output power. Since the ratio of the power distributed to both is determined by the ratio of the impedance coupled and connected to each wireless power relay unit 110, the required amount of received power for each load 122 is ensured, and Each unit is adjusted by the reception power control unit 130 so as not to be generated.

In the example in the figure, the wireless power relay unit 110 is configured as the first embodiment in which the reception relay antenna 111 and the transmission relay antenna 112 are configured. However, in the second embodiment, the wireless power relay unit 110 is configured by the transmission / reception relay antenna 113 and the feeding antenna 114. It is good also as a structure.

Further, the branch position of the wireless power relay unit 110 may be branched by the wireless power transmission unit 101 or an arbitrary power transmission relay antenna 112 without depending on the above example. The number of branches may be arbitrarily increased as long as the received power requirement of each load 122 can be secured.

DESCRIPTION OF SYMBOLS 100 Power supply 101 Wireless power transmission part 110 Wireless power relay part 111 Reception relay antenna 112 Transmission relay antenna 113 Transmission / reception relay antenna 114 Feeding antenna 120 Wireless power reception part 121 Power reception antenna 122 Load 130 Reception power control part 140 Resonance element 150 Lightning receptor 151 Ground line 160 Object to be observed

Claims

Power supply,
A power transmission unit connected to the power source and wirelessly transmitting the power obtained from the power source at a predetermined resonance frequency;
A plurality of power relay units that wirelessly receive power and wirelessly transmit to other devices;
A plurality of power receiving units that wirelessly receive the power wirelessly transmitted by the power relay unit,
The wireless power transmission system, wherein one of the power relay units receives power transmitted from the power transmission unit, and the power relay unit sequentially transmits power to the power relay unit in the subsequent stage.
The wireless power transmission system according to claim 1,
A wireless power transmission system comprising: a reception power control unit that controls a reception power amount for each power reception unit according to the number of the power reception units that receive power from the power relay unit.
The wireless power transmission system according to claim 1,
The power relay unit is a reception relay antenna that wirelessly receives power;
A transmission relay antenna that wirelessly transmits power to at least one of the reception relay antenna and the power reception unit included in another power relay unit;
A wireless power transmission system, wherein the reception relay antenna and the transmission relay antenna are electrically connected.
The wireless power transmission system according to claim 1,
The wireless power relay unit wirelessly receives power from one side and wirelessly transmits and receives power to the other, and a transmission / reception relay antenna;
A wireless power transmission system comprising: a power feeding antenna that receives a part of received power and wirelessly transmits power to the power receiving unit.
The wireless power transmission system according to claim 3 or 4,
A wireless power transmission system comprising a resonance element that resonates with the transmission relay antenna or the transmission / reception relay antenna.
The wireless power transmission system according to claim 5,
The received power control unit controls the received power amount by changing an impedance of the resonant element or an interval between the resonant element and the transmission relay antenna or the transmission / reception relay antenna. system.
A wireless power transmission system according to any one of claims 1 to 5,
The wireless power transmission system, wherein the reception power control unit is configured in the power reception unit, and controls the reception power amount by changing a resonance frequency of a power reception antenna included in the power reception unit.
A wireless power transmission system according to any one of claims 1 to 5,
The wireless power transmission system, wherein the reception power control unit is configured in the power reception unit, and controls the reception power amount by changing a load included in the power reception unit.
A wind power generator comprising the wireless power transmission system according to any one of claims 1 to 8.
The wind power generator according to claim 9,
The wireless power transmission system is mounted on a blade of the wind power generator.