JP2017143664A - Contactless power transmission device, power transmission device, and power receiving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that, in a contactless power transmission device that uses wireless communication on a power transmission side and a power receiving side for control of power transmission, safe and efficient power transmission cannot be realized when wireless communication is not established.SOLUTION: The power transmission device performs power transmission for establishing communication. When communication with a power receiving device cannot be established due to a resonance state at that time even if the power receiving device is present within a power transmission possible range, it is determined that communication is interfered and a frequency used for communication is changed. If the power receiving device cannot establish communication with the power transmission device despite having received power, it is determined that the communication is interfered and the frequency used for communication is changed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a non-contact power transmission device that performs non-contact (wireless) power transmission via a power transmission coil provided in a power transmission device and a power reception coil provided in the power reception device.

  As a method of transmitting power in a non-contact manner, an electromagnetic induction type by electromagnetic induction (several hundreds of kHz), an electric field / magnetic field resonance type by transmission between LC resonances via electric field or magnetic field resonance, a microwave power transmission type by radio waves (several GHz), Alternatively, a laser power transmission type using electromagnetic waves (light) in the visible light region is known. Among them, the electromagnetic induction type has already been put into practical use. This has the advantage that it can be realized with a simple circuit (transformer system), but there is also a problem that the transmission distance is short.

  Therefore, recently, electric field / magnetic field resonance type power transmission capable of short-distance transmission (up to 2 m) has attracted attention. Among these, in the case of the electric field resonance type, when a hand or the like is put in the transmission path, the human body is a dielectric, so that energy is absorbed as heat and dielectric loss occurs. On the other hand, in the case of the magnetic resonance type, the human body hardly absorbs energy, and dielectric loss can be avoided. From this point of view, attention to the magnetic resonance type has been increasing.

  In order to perform these contactless power transmissions safely and efficiently, the power transmission device monitors the temperature, voltage, current, and other conditions of the power reception device using radio communication using radio waves, etc. It is necessary to properly control the power to be generated.

  However, when other devices are communicating at the same frequency as the wireless communication performed by the non-contact power transmission device, or when some noise is generated, communication is not established, and power transmission cannot be controlled. . Use of IEEE802.15.4 (ZigBee (registered trademark)), IEEE802.15.1 (Bluetooth (registered trademark)), IEEE802.11 (wireless LAN), etc., which are communication systems that do not require a license for short-range communication. However, since they share the 2.4 GHz band, which is an ISM band, there is a possibility that interference occurs and communication is interrupted or communication is not established.

  Patent Document 1 discloses a non-contact charging device and a non-contact charging method capable of efficiently performing charging even in an environment where communication is easily interrupted.

JP 2015-226400 A

  In the case of the configuration disclosed in Patent Document 1, the non-contact charging device does not operate when communication is not established at the start of power transmission.

  The present invention finds a frequency at which communication is established by changing the frequency of communication when communication is not established at the start of power transmission, and provides a safe and efficient non-contact power transmission device as a result. With the goal.

  In order to solve the above problems, a non-contact power transmission device according to the present invention includes a power transmission resonator including a power transmission coil and a power transmission resonance capacitor, a power transmission circuit, a power transmission device having a power transmission communication unit, a power reception coil, A power reception device including a power reception resonator including a power reception resonance capacitor, a power reception circuit, and a power reception communication unit; and from the power transmission device to the power reception device via an action between the power transmission coil and the power reception coil. In the non-contact power transmission device that performs power transmission in a non-contact manner and wirelessly communicates between the power transmission communication unit and the power reception communication unit at a predetermined center frequency to control the power transmission, the power transmission device further includes a resonance A power reception control unit, the resonance state detection unit detects a resonance state of the power transmission resonator, and the power transmission control unit includes the resonance state. of When it is determined whether or not the power receiving device exists in the power transmission possible range of the power transmitting device based on the output result, the existence is recognized, and communication is not established between the power transmission communication unit and the power receiving communication unit The center frequency in the power transmission communication unit is changed based on a predetermined change procedure, and the power reception control unit is predetermined when communication is not established between the power transmission communication unit and the power reception communication unit. The center frequency in the power receiving communication unit is changed based on the changing procedure.

  In the present invention, when transmitting power from a power transmitting device to a power receiving device in a non-contact manner, if radio communication is not established due to interference at the frequency used for wireless communication, it is confirmed whether communication is established at another frequency. To do. If there is a frequency at which communication is established, communication is performed at that frequency. As a result, it is possible to solve the problem that the wireless power transmission apparatus cannot be controlled without establishing wireless communication, and a safe and efficient wireless power transmission apparatus can be provided.

The block diagram which shows the structure of the non-contact electric power transmission apparatus in Embodiment 1. Table showing the relationship between communication channels and center frequencies in the first embodiment The figure which shows the relationship between the communication channel and frequency in Embodiment 1. The figure which shows the relationship between the 1st communication channel and frequency in Embodiment 1. The figure which shows the relationship between the 1st communication channel and jamming electric wave in Embodiment 1. Table showing the channel change order in the first embodiment The figure which shows the operation | movement when communication cannot be performed in a 1st communication channel by jamming electric wave in Embodiment 1. The figure which shows the relationship between the distance between the power transmission apparatus and power receiving apparatus in Embodiment 1, and the resonant voltage of a power transmission resonator The figure which shows the relationship between the distance between the power transmission apparatus and power receiving apparatus in Embodiment 2, and a resonant frequency Flowchart for explaining the operation of the power transmission device according to the first embodiment. Flowchart for explaining the operation of the power receiving device in the first embodiment.

  FIG. 1 shows a configuration of a non-contact power transmission apparatus according to the present invention. The non-contact power transmission device includes a power transmission device 1 and a power reception device 2.

  The power transmission device 1 includes a power transmission coil 4 for non-contact transmission of high-frequency power. The power receiving device 2 includes a power receiving coil 9 for receiving high frequency power supplied from the power transmitting coil 4. In the non-contact power transmission apparatus having the configuration of FIG. 1, for example, power can be transmitted from the power transmission apparatus 1 to the power reception apparatus 2 through magnetic field resonance between the power transmission coil 4 and the power reception coil 9. In addition, the connection form of the power transmission coil 4 and the power reception coil 9 can be appropriately employed such as electromagnetic induction, radio wave, electric field or magnetic field sharing.

  The power transmission device 1 further includes a power transmission resonator including the power transmission coil 4 and the power transmission resonance capacitor 5, a resonance state detection unit 6 that detects a resonance state of the power transmission resonator, and a power transmission communication unit 7 that performs communication with the power reception device 2. Based on information of the resonance state detection unit 6 and the power transmission communication unit 7, the power transmission control unit 8 that changes the frequency of communication in the power transmission communication unit 7 and the message display unit 15 that displays the communication status are included.

  The power receiving device 2 further includes a power receiving resonator including the power receiving coil 9 and the power receiving resonance capacitor 10, a power receiving circuit 11 that converts the received power, an output terminal 12 that outputs the power converted by the power receiving circuit 11, and power transmission. A power reception communication unit 13 that performs communication with the apparatus, and a power reception control unit 14 that changes the frequency of the communication frequency in the power reception communication unit 13 based on the status information of the power reception circuit 11 and information from the power reception communication unit 13 are included.

  The resonance state detection unit 6 detects the resonance state of the power transmission resonator. For detection of the resonance state, measurement of the resonance voltage and resonance frequency at both ends of the power transmission coil 4 is suitable.

  The power transmission communication unit 7 communicates with the power reception communication unit 13 wirelessly. The power transmission communication unit 7 and the power reception communication unit 13 can be configured using an existing communication module, or can be configured by a unique circuit. As a method for wireless communication, an existing standard such as IEEE802.15.4 (ZigBee (registered trademark)), IEEE802.15.1 (Bluetooth (registered trademark)), IEEE802.11 (wireless LAN), or the like can be used. It can also be configured in its own way.

  In addition, since the frequency at which power is transmitted in contactless power transmission is sufficiently smaller than the frequency of the wireless communication, the influence of radiation noise associated with contactless power transmission on wireless communication can be ignored. In this embodiment, the frequency of non-contact power transmission is 100 kHz or less.

  The power transmission control unit 8 receives information about the resonance state of the power transmission resonator detected by the resonance state detection unit 6, information that the power transmission communication unit 7 has established communication with the power reception communication unit 13, and reception obtained as a result of the communication. The transmission power of the power transmission circuit 3 is controlled using the information of the device 2. When communication between the power transmission communication unit 7 and the power reception communication unit 13 is not established, the power transmission control unit 8 controls the frequency used by the power transmission communication unit 7 for communication according to a predetermined procedure.

  The power reception control unit 14 controls the frequency used by the power reception communication unit 13 for communication according to a predetermined procedure based on the status information of the power reception circuit 11 and information that the power reception communication unit 13 has established communication with the power transmission communication unit 7. To do.

  Control of the frequency used by the power transmission communication unit 7 and the power reception communication unit 13 for communication is a feature of the present invention, which will be described in detail later.

  The power transmission control unit 8 and the power reception control unit 14 are preferably configured by a microcomputer, but may be configured by an FPGA or an electronic circuit.

  The power transmission circuit 3 supplies a relatively large AC power to the power transmission resonator using a power circuit using a semiconductor switching element or the like. Here, the frequency at the time of power transmission is determined by the resonance frequency of the power transmission resonator including the influence of the interaction with the power reception resonator.

  A power receiving circuit 11 is connected to a power receiving resonator including the power receiving coil 9 and the power receiving resonance capacitor 10. The power receiving circuit 11 detects and smoothes the high frequency power received by the power receiving coil 9, converts it to a required power format, and outputs it from the power output terminal 12.

  The above is the outline of the operation in the non-contact power transmission apparatus of the present invention.

The present invention is characterized by the above-described resonance state detection and communication frequency control of the communication unit. Hereinafter, the features of the present invention will be described in detail for each embodiment.
<Embodiment 1>
FIG. 2 is a table showing the relationship between the communication channels that can be used in the power transmission communication unit 7 and the power reception communication unit 13 used in the first embodiment and the respective center frequencies. In the present embodiment, it is assumed that communication similar to IEEE802.15.4 is performed, but the present invention is not necessarily limited to this, and other communication such as IEEE802.11 can also be used.

  FIG. 3 is a diagram showing the relationship between the frequency of each channel CH1 to CH16 and the radio wave intensity. In this embodiment, 16 communicable channels are prepared in advance, but the number of channels is not limited to 16.

  FIG. 4 is a diagram showing the relationship between the frequency and the radio wave intensity when communication is performed using CH1. CH1 performs communication with a center frequency of 2405 MHz.

  FIG. 5 is a diagram showing the relationship between the frequency and the radio wave intensity when the jamming radio wave exists in the vicinity of about 2400 MHz to 2425 MHz when communication is performed using CH1. If there is an interference radio wave as shown in FIG. 5 in the vicinity of CH1, communication using CH1 may not be established. Therefore, the communication channel is changed as shown below and an attempt is made to establish communication between the power transmission communication unit 7 and the power reception communication unit 13.

  The communication is established when authentication or pairing is performed between the power transmission communication unit 7 and the power reception communication unit 13. If authentication of a predetermined pattern can be performed, it is considered that the power transmission communication unit 7 and the power reception communication unit 13 that are partners of correct communication are within a communicable range and are in a communicable state. Start. Note that the authentication accuracy can be improved by repeating the authentication of the pattern a plurality of times as necessary.

  FIG. 6 shows the order in which the power transmission control unit 8 and the power reception control unit 14 change the communication channel. First, communication is performed using CH1, which is the communication channel in the change order 1, and communication is performed using CH9, which is the communication channel in the change order 2, if communication is not established on CH1. Thereafter, when communication is not established with the set communication channel, the communication channel is sequentially changed according to FIG. The communication channel is changed up to the change order 16. If communication is not established on CH1, or if communication is established once on CH1, but is interrupted, it is not changed to CH9 in the change order 2, but communication on CH1 is performed again before the change order is followed. You may try to establish.

  FIG. 7 is a diagram showing the relationship between the frequency and the radio wave intensity when the communication channel is changed to CH9 according to the change order of the communication channel shown in FIG. 6 when the communication at CH1 in FIG. It is. If there is a jamming radio wave and communication is not established, the communication channel is changed from CH1 to CH9 according to the change order predetermined in FIG.

  FIG. 8 shows the relationship between the distance between the power transmission device and the power reception device and the resonance voltage of the power transmission resonator. In the first embodiment, the resonance state detection unit 6 measures the voltage across the power transmission coil 4 constituting the power transmission resonator. In the first embodiment, it is assumed that power transmission can be suitably performed with a distance between the power transmission device 1 and the power reception device 2 of 15 to 35 mm. In a non-contact power transmission apparatus using a resonator, the resonance voltage varies depending on the distance between the power transmission resonator and the power reception resonator, and the resonance voltage becomes very high when the distance is long or when there is no power reception resonator.

  FIG. 10 shows a flowchart of control of the power transmission control unit 8 according to Embodiment 1 of the present invention. Hereinafter, the operation on the power transmission device 1 side will be described with reference to FIG.

  When the power transmission device 1 starts operating, the power transmission control unit 8 substitutes 1 for the change order N of the communication channels used by the power transmission communication unit 7 for communication (step S101).

  Here, the order in which the communication channels are changed is determined as shown in FIG. 6. The change order No. 1 is the communication channel CH1, the change order No. 2 is the order of the communication channels CH9,. This change order can be changed in the order of frequencies such as CH1 and CH2, or can be changed with an interval in frequency as shown in FIG. This may be determined on the assumption of the frequency used for communication or the assumed interference, or may be determined by observing the radio wave at the place where it is actually operated. Further, it is not necessary to use all of the communication channels, and the number of communication channels may be limited, such as using only two when there are three or more communication channels.

  The power transmission control unit 8 specifies a communication channel used by the power transmission communication unit 8 based on the value of the change order N (step S102). The communication channel change order is the same as that shown in FIG. 6, and CH1 is designated when the change order N = 1. Therefore, when the relationship between the communication channel and the center frequency is the table of FIG. 2, the communication channel is CH1, and therefore communication is performed at 2405 MHz.

  Next, the power transmission control unit 8 transmits power to the power transmission circuit 3 with low power (step S103). Here, the low power is power necessary for establishing communication when the power transmitting device and the power receiving device are arranged at an appropriate distance. This is because when a large amount of power is transmitted when the power receiving side is not arranged at an appropriate distance or when communication is not established, the circuit may be damaged or the leakage magnetic field to the outside may increase. .

  The power receiving device 2 starts operation by low power transmission from the power transmitting device 1.

  In the state of low power transmission, it is confirmed whether communication between the power transmission side and the power reception side is established. When communication is established, transmission with normal high power is started. When communication is not established, the process proceeds to step S105 (step S104).

  When communication is not established in step S104, the power transmission control unit 8 detects whether or not the power receiving device 2 exists in the power transmission possible range of the power transmitting device 1 (step S105). The resonance voltage detected by the resonance state detection unit 6 can be used to confirm the power reception target. As described above, FIG. 8 shows the relationship between the distance between the power transmitting device 1 and the power receiving device 2 and the resonance voltage of the co-transmission resonator. For example, if the preferable distance is 15 to 35 mm, the determination criterion is set to V0. When the power transmission resonance voltage is equal to or higher than V0, it is determined that “no power reception target” and the process proceeds to step S110. When the resonance voltage is less than V0, it is determined that “the power reception target is present”, and the process proceeds to step S106.

  When it is determined in step S105 that “there is a power reception target”, it is confirmed whether or not the specified time has elapsed since the communication frequency was set (step S106). The reason for providing the designated time is that it takes time until the communication is established after the communication channel is designated, and the channel change times of the power transmission communication unit 7 and the power reception communication unit 13 may be shifted. This is to wait for the difference. When the designated time has not elapsed, steps S104 to S106 are repeatedly executed. If the communication is not established and the power receiving target continues to exist even after the specified time has elapsed, the process proceeds to step S107.

  If it is determined in step S106 that the specified time has elapsed after setting the communication frequency, it is determined whether the change order N is equal to or greater than the maximum value in the channel order (step S107). Here, the channel change order is as shown in FIG. 6, and when the change order N is 16 or more, it is determined that “no power reception target” or “no channel available for communication” and communication is terminated. The process proceeds to step S110. On the other hand, when the change order N is less than 16, the process proceeds to step 108.

  When the change order N is less than 16, 1 is added to the change order N (step S108).

  The communication channel of the power transmission communication unit is set according to the value of the change order N (step S109). For example, when this step is executed for the first time, the change order N = 2, and at that time, CH9 in the change order 2 is set as the communication channel from FIG. Then, it progresses to step 104.

  When it is determined in step S105 that there is no power reception target, when it is determined in step S107 that the change order N has reached the maximum value in the change order, the communication of the power transmission communication unit 7 is terminated (step S110). When the communication is terminated in this step, a message indicating that the communication is terminated is displayed on the message display unit 15.

  After step S110, power transmission is terminated (step S111). When the power transmission is finished, the power transmission device 1 stops, the power supplied to the power reception device 2 disappears, and the power reception side also stops. When power transmission is terminated in this step, a message indicating that power transmission is terminated is displayed on the message display unit 15.

  The operation on the power transmission device 1 side has been described above centering on the control of the power transmission control unit 8. Next, the operation on the power reception device 2 side will be described focusing on the control of the power reception control unit 14.

  FIG. 11 shows a flowchart of control of the power reception control unit 14 in Embodiment 1 of the present invention. Hereinafter, the operation on the power receiving device 2 side will be described with reference to FIG.

  First, the power reception control unit 14 of the power reception device 2 starts operation by receiving power transmission from the power transmission device 1 in a contactless manner.

  Next, similarly to the power transmission control unit 8, the power reception control unit 14 substitutes 1 for the change order N of the communication channels used by the power reception communication unit 13 for communication (step S201).

  And the power reception control part 14 designates the communication channel which the power receiving communication part 13 uses based on the value of the change order N similarly to the power transmission control part 8 (step S202).

  In this state, it is confirmed whether communication between the power receiving communication unit 13 and the power transmission communication unit 7 is established. When communication is established, normal high power transmission is started, and when communication is not established, the process proceeds to step S204. Proceed (step S203).

  When communication is not established in step S203, it is confirmed whether the specified time has elapsed after setting the communication frequency (step S204). This designated time is the same as the designated time in S106 on the power transmission side. When it takes time from when the power transmission device starts to operate until the power reception device starts operation, it is desirable to set the designated time so that the frequency change of the power transmission device and the frequency change of the power reception device occur at substantially the same time. . When the designated time has not elapsed, step S203 is repeatedly executed. When the designated time has elapsed, the process proceeds to step S205.

  When it is determined in step S204 that the specified time has elapsed after setting the communication frequency, it is determined whether the change order N is equal to or greater than the maximum value in the channel order, as in the power transmission control unit (step S205). When the change order N is 16 or more, it is determined that there is no usable channel for communication, and the process proceeds to step S207 to end. When the change order N is less than 16, the process proceeds to step 206.

  When the change order N is less than 16, 1 is added to the change order N, and the process proceeds to step S202 (step S206).

  When it is determined in step S205 that the change order N has reached the maximum value in the change order, the communication of the power receiving communication unit 13 is ended and the operation is ended (step S207). Thereafter, the power transmission device 1 stops, the power supplied to the power reception device 2 disappears, and the power reception side also stops.

  Heretofore, the operation on the power receiving device 2 side has been described focusing on the control of the power reception control unit 14.

  According to the above, there is an interference radio wave as shown in FIG. 7, and the operation when communication is not established on CH1 is as follows.

  The first communication channel of the power transmission device 1 is the change order N = 1, and power transmission is started with low power in order to attempt communication on CH1. The power receiving device 2 receives the power transmission from the power transmission device 1 and starts operation. The receiving apparatus 2 also uses the CH1 as the first communication channel in the order of change N = 1.

  The power transmitting device 1 and the power receiving device 2 try to communicate with each other through CH1, but communication is not established because there is a disturbing radio wave as shown in FIG.

  Thereafter, after the specified time has elapsed, both the power transmitting device 1 and the power receiving device 2 are set to the change order N = 2, and communication is attempted using CH9.

Since there is no jamming radio wave in CH9, communication is established, and the power transmission device 1 starts normal high-power transmission. The power receiving device 2 starts receiving power with normal high power, and non-contact power transmission between the power transmitting device 1 and the power receiving device 2 is started.
<Embodiment 2>
The second embodiment is different from the first embodiment in that the resonance state detection unit 6 does not measure the resonance voltage of the power transmission resonator but detects the resonance frequency of the power transmission resonator.

  FIG. 9 is a diagram illustrating the relationship between the distance between the power transmission device 1 and the power reception device 2 and the resonance frequency. If a suitable distance between the power transmitting device 1 and the power receiving device 2 is 15 to 35 mm, the determination criterion is set to f0.

  In step S105, when the resonance frequency is less than f0, the process proceeds to step S110 in order to determine that “no power reception target” and end. When the resonance frequency is greater than or equal to f0, it is determined that “a power reception target exists” and the process proceeds to step S106.

  Since other operations are the same as those in the first embodiment, detailed description thereof is omitted.

  As described above, the contactless power transmission device of the present invention uses different frequencies even when interference such as interference occurs in wireless communication between the power transmitting device and the power receiving device and wireless communication is not established. By performing this, safe and efficient non-contact power transmission can be performed.

  In addition, according to the above embodiment, the power receiving device 2 is mounted on a mobile phone or a smartphone, and the power transmission device 1 is mounted on the charger side, so that the secondary mounted on the mobile phone or the smartphone safely and efficiently. The battery can be charged. In addition, if the present invention is used for a robot, a transporter, a drone, etc., safe and efficient non-contact power transmission is possible even in an environment where there is a large amount of communication noise such as jamming radio waves. As a result, the robot, the transporter, the drone It is possible to guarantee stable operation.

  The non-contact power transmission device of the present invention enables efficient and safe power transmission even when there is interference such as interference radio waves from the outside near the communication frequency.

DESCRIPTION OF SYMBOLS 1 Power transmission apparatus 2 Power reception apparatus 3 Power transmission circuit 4 Power transmission coil 5 Power transmission resonance capacity 6 Resonance state detection part 7 Power transmission communication part 8 Power transmission control part 9 Power reception coil 10 Power reception resonance capacity 11 Power reception circuit 12 Power output terminal 13 Power reception communication part 14 Power reception control Part 15 Message display part

Claims (6)

A power transmission device including a power transmission resonator including a power transmission coil and a power transmission resonance capacity, a power transmission circuit, and a power transmission communication unit;
A power receiving resonator including a power receiving coil and a power receiving resonance capacitor; a power receiving circuit having a power receiving circuit; and a power receiving communication unit.
Non-contact power transmission from the power transmission device to the power reception device through the action between the power transmission coil and the power reception coil,
In the non-contact power transmission device for controlling the power transmission by wirelessly communicating between the power transmission communication unit and the power reception communication unit at a predetermined center frequency,
The power transmission device further includes a resonance state detection unit and a power transmission control unit,
The power reception device further includes a power reception control unit,
The resonance state detection unit detects a resonance state of the power transmission resonator,
The power transmission control unit determines whether the power receiving device exists in a power transmission possible range of the power transmission device based on the detection result of the resonance state, recognizes the existence, and transmits the power transmission communication unit and the power receiving unit. When communication is not established between communication units, based on a predetermined change procedure, change the center frequency in the power transmission communication unit,
The power reception control unit changes the center frequency in the power reception communication unit based on a predetermined change procedure when communication is not established between the power transmission communication unit and the power reception communication unit. Non-contact power transmission device.   The contactless power transmission device according to claim 1, wherein the resonance state detection unit detects a resonance voltage of the power transmission resonator as the resonance state.   The contactless power transmission device according to claim 1, wherein the resonance state detection unit detects a resonance frequency of the power transmission resonator as the resonance state.   The non-contact power transmission device according to claim 1, wherein the center frequency is 2400 MHz or more and 2500 MHz or less. Power is transmitted in a non-contact manner through an action between a power transmission coil mounted on the power transmission device and a power reception coil mounted on the power reception device, and a power transmission communication unit mounted on the power transmission device and a power reception mounted on the power reception device. A power transmission device for non-contact power transmission that wirelessly communicates between communication units at a predetermined center frequency to control the power transmission,
The power transmission device further includes a power transmission resonator including a power transmission coil and a power transmission resonance capacity, a power transmission circuit, a resonance state detection unit, and a power transmission control unit.
The resonance state detection unit detects a resonance state of the power transmission resonator,
The power transmission control unit determines whether the power receiving device exists in a power transmission possible range of the power transmission device based on the detection result of the resonance state, recognizes the existence, and transmits the power transmission communication unit and the power receiving unit. A power transmission apparatus for non-contact power transmission, wherein, when communication is not established between communication units, the center frequency in the power transmission communication unit is changed based on a predetermined change procedure. Power is transmitted in a non-contact manner through an action between a power transmission coil mounted on the power transmission device and a power reception coil mounted on the power reception device, and a power transmission communication unit mounted on the power transmission device and a power reception mounted on the power reception device. A power receiving device for non-contact power transmission that wirelessly communicates between communication units at a predetermined center frequency to control the power transmission,
The power reception device further includes a power reception control unit,
The power reception control unit changes the center frequency in the power reception communication unit based on a predetermined change procedure when communication is not established between the power transmission communication unit and the power reception communication unit. A power receiving device for a non-contact power transmission device.

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