JP6507036B2 - Non-contact power feeding device and non-contact power receiving device - Google Patents

Description

  The present invention relates to a non-contact power feeding device and a non-contact power receiving device used in a non-contact power feeding system for wirelessly feeding power by electromagnetic coupling, and in particular, proximity and position of the non-contact power feeding device and the non-contact power receiving device. The present invention relates to a noncontact power feeding device and a noncontact power reception device capable of detecting a shift.

  As a foreign object detection technique, such as a metal foreign object etc. in a non-contact electric supply system, what was indicated to patent documents 1 and 2 is known, for example.

  In the wireless power transmission device described in Patent Document 1 (see FIGS. 3 to 8, non-patent document 1, claims 1, paragraphs [0046]-[0080]), both sides of the feeding coil (first self-resonant coil) are provided. The first self-resonant coil for detecting foreign matter and the second self-resonant coil for detecting foreign matter are disposed in the same direction as the feed coil, and the second self-resonant coil for detecting foreign matter is connected to the second self-resonant coil for foreign matter detection. While supplying the high frequency energy E1 of the resonance frequency which resonates with the resonance coil, energy E2 of the alternating current induced in the second self-resonance coil for detecting foreign matter is detected, and energy transfer efficiency P1 = E2 / E1 between the two is determined. When the transmission efficiency P1 becomes equal to or less than a predetermined threshold value, foreign object detection is performed by determining that the foreign object is present.

  In the non-contact power transmission system (see paragraphs [0036] to [0037] of FIG. 5, FIG. 6, FIG. 6) of Patent Document 2, a feeding coil (primary coil), a cover covering the feeding coil, A sensor coil for detecting an object present around the cover is provided, and a winding axis of the sensor coil is disposed to be substantially orthogonal to a winding axis of the feeding coil. The sensor coil is disposed so that the feeding coil and the core of the feeding coil are wound around and the magnetic flux generated by the feeding coil and the magnetic flux generated by the sensor coil are orthogonal to each other. In this configuration, when foreign matter is present on the cover, the impedance around the sensor coil changes and the resonant frequency of the sensor coil deviates. Therefore, foreign matter detection is performed by detecting the deviation of the resonance frequency of the sensor coil. Further, the configuration in which the winding axis of the sensor coil is substantially orthogonal to the winding axis of the feeding coil suppresses interference between both coils and improves the accuracy of foreign matter detection.

  On the other hand, in the non-contact power feeding system, for example, Patent Documents 3 and 4 are known as a technique for detecting the approach and positional deviation of the non-contact power feeding device and the non-contact power receiving device.

  Patent Document 3 (see claim 1, FIG. 1, FIG. 17, paragraphs [0039] and [0044]-[0046] of Patent Document 3) includes a feeding coil (1), a receiving coil (7) and a receiving capacitor. (8) A wireless power feeding device for supplying power without contact to a wireless power receiving device having a power receiving resonant circuit, comprising: a resonant coil (1) and a resonant current detector for detecting a resonant current of the power receiving resonant circuit 6) By supplying an alternating current to the feeding coil (1), power is supplied from the feeding coil (1) to the receiving coil (7) based on the magnetic field resonance phenomenon of the feeding coil (1) and the receiving coil (7) A control circuit for performing supply, the control circuit (111) correlating the frequency of the alternating current with the frequency of the resonant current detected by the resonant current detector; and the feeding coil (1) is substantially resonant circuit Not constituted, the resonance current detector (6) has a detection resonance circuit including a detection coil (6a) and a detection capacitor (6c), and the magnetic field resonance phenomenon of the detection coil (6a) and the power receiving coil (7) Based on the above, the resonance current of the power reception resonance circuit is detected, the winding area of the detection coil (6a) is smaller than the winding area of the feeding coil (1), and the detection coil (6a) has a winding central axis that is the feeding coil. A wireless power feeder is described which is arranged at an angle of 80 ° to 100 ° with respect to the magnetic field vector generated by (1). When the power receiving coil (7) approaches the power feeding coil (1), a resonant current is induced in the power receiving coil (7). At this time, the detection resonance circuit including the detection coil (6a) and the detection capacitor (6c) resonates by the resonance current, and the resonance current induced in the detection resonance circuit is detected to receive power at the wireless power feeding device side. It is possible to detect the approach of the coil (7).

  Patent Document 4 (see FIGS. 1-3, paragraphs [0040] to [0049] of Patent Document 4) includes a power receiving device (20) installed on a moving body and having a power receiving coil (103), and a power receiving coil (103) A power transmission device (10) having a power transmission coil (102) for supplying power without contact, and a plurality of loop antenna elements disposed in the vicinity of the power transmission coil (102) and having their respective loop axes orthogonal to one another A second antenna having a plurality of loop antenna elements disposed in the vicinity of the antenna (301) and the power receiving coil (102) and having the coil axis direction of the power receiving coil (102) substantially coincident with the loop axis direction 304) relative to the transmitting coil (102) and the receiving coil (103) based on the received magnetic field by the plurality of loop antenna elements of the first antenna (301). Wireless power transmission system and a position calculating means for obtaining a location relationship (308) is described.

JP 2012-75200 A JP, 2013-215073, A Patent No. 55222271 specification JP 2012-5308 A

  In the non-contact power feeding system described in Patent Documents 1, 2, and 3, although it is possible to detect the approach of a foreign object or a power receiving coil, whether the non-contact power receiving device has approached a predetermined position for feeding power. It can not be detected.

  On the other hand, in the non-contact power feeding system described in Patent Document 4, a non-contact power feeding device uses a first antenna (301) on the non-contact power feeding device side and a second antenna (304) on the non-contact power receiving device side. Since the position of the contact power reception device can be specified, it is possible to detect whether or not the non-contact power reception device has approached a predetermined position for feeding power. However, as the precondition, it is premised that the non-contact power reception device is provided with the second antenna (304), and the detection mechanism is not closed on one side of the non-contact power feeding device or the non-contact power reception device. . Therefore, there is a problem of lack of versatility.

  Therefore, an object of the present invention is to provide a noncontact power feeding device capable of detecting the proximity of the noncontact power feeding device and the noncontact power receiving device to each other and the positional deviation thereof only on one side of the noncontact power feeding device or the noncontact power receiving device. And providing a non-contact power reception device.

According to a first configuration of the non-contact power feeding device of the present invention, a non-contact power feeding device including a feeding coil to which alternating current power is fed, and the power feeding coil are detachably attached to the feeding coil and resonate with the feeding coil. A non-contact power feeding device used in a non-contact power feeding system, comprising: a non-contact power receiving device having a power receiving coil receiving power supply from the power feeding coil;
In a plane of a first central cross section which is a plane including a central axis of the feeding coil, a first detection coil is provided, the winding axis of which is oriented in a direction perpendicular to the first central cross section. ,
The first detection coil is disposed so as to enclose the feeding coil in a coil ring of the first detection coil,
First electromotive force detection means for detecting an intensity of an electromotive voltage or an electromotive current generated in the first detection coil;
First phase difference detection means for detecting a phase difference between a phase of a voltage or current supplied to the feeding coil and a phase of an electromotive voltage or current generated in the first detection coil;
A positional deviation detection unit that determines the presence or absence of positional deviation of the power receiving coil with respect to the power feeding coil by determining the threshold of the strength of the electromotive voltage or electromotive current detected by the first electromotive force detection unit;
First misregistration direction detection means for detecting misregistration direction in the central axis direction (hereinafter referred to as “x-axis direction”) of the first detection coil based on the phase difference detected by the first phase difference detection means And.

  According to this configuration, when the power receiving coil is in the vicinity of the power feeding coil and coaxial with the power feeding coil (hereinafter, this position is referred to as “immediately above position”), the electromotive voltage (or the induced voltage generated in the first detection coil) The electromotive current) is minimized (approximately zero). When the position of the power receiving coil deviates in the x-axis direction from the position directly above the feeding coil, an electromotive voltage (or electromotive current) is generated in the first detection coil. At this time, the phase of the electromotive voltage (or electromotive current) generated in the first detection coil is shifted by 90 degrees with respect to the phase of the voltage (or current) supplied to the feeding coil. Further, whether the phase of the electromotive voltage (or electromotive current) is advanced by 90 degrees or delayed by 90 degrees is determined depending on whether it is shifted in the positive direction or in the negative direction in the x-axis direction. Therefore, the magnitude of the electromotive voltage (or electromotive current) is detected by the first electromotive force detection means, and the positional deviation detection means determines the threshold value, thereby detecting the presence or absence of positional deviation of the power receiving coil with respect to the power feeding coil. It can be determined. Further, the first phase difference detection means detects a phase difference of the phase of the electromotive voltage (or electromotive current) with respect to the phase of the voltage (or current) supplied to the feeding coil, and the first positional deviation direction detection means By detecting the direction of displacement based on whether the phase difference is positive or negative, the occurrence of displacement and the direction of displacement along the x-axis can be detected.

A second configuration of the non-contact power feeding device according to the present invention is, in the first configuration, a second center including a central axis of the feeding coil and being a plane perpendicular to the first central cross section. In the plane of the cross section, there is provided a second detection coil whose winding axis is oriented perpendicular to the second central cross section,
The second detection coil is disposed so as to enclose the feeding coil in a coil ring of the second detection coil,
A second electromotive force detection unit that detects the intensity of an electromotive voltage or an electromotive current generated in the second detection coil;
Second phase difference detection means for detecting a phase difference between the phase of the voltage or current supplied to the feeding coil and the phase of the electromotive voltage or current generated in the second detection coil;
A positional deviation detection unit that determines the presence or absence of positional deviation of the power receiving coil with respect to the power feeding coil by performing threshold determination on the strength of the electromotive voltage or electromotive current detected by the second electromotive force detection unit;
Second misalignment direction detecting means for detecting misalignment direction of the central axis direction (hereinafter referred to as “y-axis direction”) of the second detection coil based on the phase difference detected by the second phase difference detection means And.

  This makes it possible to detect the occurrence and direction of displacement in both the x-axis direction and the y-axis direction in a two-dimensional plane.

In a third configuration of the non-contact power feeding device according to the present invention, in the first or second configuration, a winding shaft does not approach the side of the power feeding coil, and the power receiving coil does not approach the power feeding coil. A third detection coil disposed in a direction perpendicular to the magnetic flux produced by the feed coil in a state;
Third phase difference detection means for detecting a phase difference between the phase of the voltage or current supplied to the feeding coil and the phase of the electromotive voltage or current generated in the third detection coil;
And resonance frequency control means for controlling the frequency of the voltage or current supplied to the feeding coil such that the phase difference detected by the third phase difference detecting means becomes a predetermined value. I assume.

  According to this configuration, when the power receiving coil does not have the power receiving coil, the induced voltage (or induced current) generated in the third detection coil when the alternating current is supplied to the power feeding coil is substantially zero. . On the other hand, when the power receiving coil approaches the vicinity of the feed coil, an induced voltage (or induced current) is generated in the third detection coil. At this time, when the frequency of the alternating current supplied to the feeding coil coincides with the resonant frequency between the feeding coil and the receiving coil, the phase of the alternating voltage (or alternating current) supplied to the feeding coil and the third detection The phase difference from the phase of the induced voltage (or induced current) induced in the coil is 90 degrees. However, when the frequency of the alternating voltage (or alternating current) supplied to the feed coil is slightly deviated from the resonance frequency, the phase difference deviates from 90 degrees according to the amount of deviation. Therefore, the third phase difference detection means detects the phase of the induced voltage (or induced current), and the resonance frequency control means supplies power so that the phase difference becomes a predetermined value (absolute value is 90 degrees). By controlling the frequency of the voltage or current supplied to the coil, the frequency of the alternating voltage (or alternating current) supplied to the feeding coil can be automatically made to coincide with the resonance frequency to maximize the power transmission efficiency. .

A fourth configuration of the non-contact power feeding device according to the present invention is, in the third configuration, a third electromotive force detection unit that detects the intensity of an electromotive voltage or electromotive current generated in the third detection coil. When,
Presence / absence detection means for determining whether or not the power receiving coil is present in the vicinity of the power feeding coil by determining the threshold of the strength of the electromotive voltage or the electromotive current detected by the third electromotive force detection means; It is characterized by

  According to this configuration, the third electromotive force detection means detects the strength of the electromotive voltage or current generated in the third detection coil, and the presence / absence detection means determines the strength as a threshold, thereby providing the vicinity of the feed coil. It can be detected whether or not there is a receiving coil.

In a first configuration of the non-contact power reception device according to the present invention, a non-contact power feeding device including a feeding coil to which alternating current power is fed, and the feeding coil are detachably attached to the feeding coil and resonate with the feeding coil. A non-contact power receiving device used in a non-contact power feeding system comprising: a non-contact power receiving device including a power receiving coil receiving power supply from the power feeding coil, wherein
In a plane of a first central cross section which is a plane including a central axis of the power receiving coil, a first detection coil is provided, the winding axis of which is oriented in a direction perpendicular to the first central cross section. ,
The first detection coil is disposed so as to enclose the power receiving coil in a coil ring of the first detection coil,
First electromotive force detection means for detecting an intensity of an electromotive voltage or an electromotive current generated in the first detection coil;
First phase difference detection for detecting a phase difference between a phase of voltage or current induced in the power receiving coil by an alternating magnetic field generated by the feeding coil and a phase of electromotive voltage or current generated in the first detection coil Means,
A first positional deviation detection unit that determines presence or absence of positional deviation of the power receiving coil with respect to the power feeding coil by determining a threshold of the strength of the electromotive voltage or electromotive current detected by the first electromotive force detection unit;
A first position for detecting the direction of positional deviation and the amount of positional deviation in the central axis direction (hereinafter referred to as “x-axis direction”) of the first detection coil based on the phase difference detected by the first phase difference detection means And a shift direction detection unit.

  With this configuration, it is possible to detect the occurrence of positional deviation between the feeding coil and the receiving coil and the direction of positional deviation along the x-axis on the non-contact power receiving device side.

A second configuration of the non-contact power reception device according to the present invention is, in the first configuration, a second center including a central axis of the power receiving coil and being a plane perpendicular to the first central cross section. In the plane of the cross section, there is provided a second detection coil whose winding axis is oriented perpendicular to the second central cross section,
The second detection coil is disposed so as to enclose the power receiving coil in a coil ring of the second detection coil,
A second electromotive force detection unit that detects the intensity of an electromotive voltage or an electromotive current generated in the second detection coil;
A second phase difference detection that detects a phase difference between a phase of a voltage or current induced in the power receiving coil by an alternating magnetic field generated by the feeding coil and a phase of an electromotive voltage or current generated in the second detection coil Means,
Second positional deviation detection means for judging presence / absence of positional deviation of the power receiving coil with respect to the power feeding coil by making a threshold judgment on the strength of the electromotive voltage or electromotive current detected by the second electromotive force detecting means;
A second position for detecting the direction of positional deviation and the amount of positional deviation in the central axis direction (hereinafter referred to as "y-axis direction") of the second detection coil based on the phase difference detected by the second phase difference detection means And a shift amount detection unit.

  With this configuration, it is possible to detect the occurrence of positional deviation between the feeding coil and the receiving coil and the direction of positional deviation along the x-axis and y-axis on the non-contact power reception device side.

  As described above, according to the non-contact power feeding device of the present invention, even if the detection mechanism is not provided on the non-contact power receiving device side, the non-contact power reception near the power feeding coil only from the non-contact power feeding device side. It is possible to detect whether or not the power receiving coil of the device has approached, and to detect the positional deviation and the positional deviation direction. Further, by providing the third phase difference detection means and the resonance frequency control means, even when the resonance frequency changes due to aging deterioration of the power feeding coil or the power receiving coil, an alternating number is used to energize the power feeding coil following it. The frequency of the current can be automatically matched to the resonant frequency to maximize power transfer efficiency.

  Further, according to the non-contact power reception device of the present invention, even if the detection mechanism is not particularly provided on the non-contact power feeding device side, the positional deviation and position of the power receiving coil with respect to the feeding coil only from the non-contact power reception device side. It becomes possible to detect the shift direction.

It is a block diagram showing the composition of the non-contact electric supply system concerning Example 1 of the present invention. It is a schematic diagram which shows the feed coil assembly 6 in FIG. FIG. 7 is a diagram showing an example of a magnetic field generated around the feeding coil 3 when the feeding coil 3 is energized in a state where the receiving coil 30 is not in the vicinity of the feeding coil 3; It is a schematic diagram showing change of a magnetic field formed near both coils at the time of receiving coil 30 of non-contacting electric power receiving device 2 approaching feed coil 3 of non-contacting electric power feeding device 1. It is a perspective view of feed coil assembly 6 used by measurement experiment of electromotive force. It is a figure showing the physical relationship of feed coil assembly 6 and receiving coil 30 in measurement experiment of electromotive force. It is a voltage waveform of the feed coil 3, the receiving coil 30, and the detection coil 4 in the measurement position B and C of FIG. It is a flowchart showing position shift correction | amendment control operation of the movement control circuit 17 of the non-contact electric power supply 1 of FIG. It is a block diagram showing the structure of the non-contact electric power feeding system which concerns on Example 2 of this invention. It is a schematic diagram which shows the feed coil assembly 6 in FIG. It is a figure showing the specific structural example of the feed coil 3 of FIG. 10, and detection coil 4a, 4b. It is a block diagram showing the composition of the non-contact electric supply system concerning Example 3 of the present invention. It is a schematic diagram which shows the feed coil assembly 6 in FIG. It is a flowchart showing position shift correction control operation of movement control circuit 17 of non-contact electric supply 1 of Drawing 12, and energization mode change operation of energization control circuit 12. It is a block diagram showing the composition of the non-contact electric supply system concerning Example 4 of the present invention.

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

  FIG. 1 is a block diagram showing a configuration of a non-contact power feeding system according to a first embodiment of the present invention. FIG. 2 is a schematic view showing the arrangement of the feed coil 3 and the detection coil 4 in FIG. The noncontact power feeding system of the present embodiment includes a noncontact power feeding device 1 and a noncontact power receiving device 2.

  The non-contact power feeding device 1 includes a feeding coil assembly 6 including a feeding coil 3 and a detecting coil 4, a motor 7, a power supply circuit 10, an oscillation circuit 11, an energization control circuit 12, an electromotive force detection circuit 13, and a displacement detection circuit 16. A movement control circuit 17, a phase difference detection circuit 18, and a displacement direction detection circuit 19 are provided.

  As shown in FIG. 2, the feeding coil assembly 6 integrally incorporates the feeding coil 3 and the detection coil 4. The feeding coil 3 is a coil which is fed with an alternating current and performs noncontact power transmission to the noncontact power receiving apparatus 2. Usually, a cored coil as shown in FIG. 2 is used for the feeding coil 3. In FIG. 2, the feed coil 3 is a cylindrical coil and the core 3 a of the feed coil is a cylindrical core for the sake of convenience of illustration, but in the present invention, the feed coil 3 and the core of the feed coil The shape of 3a is not limited to this, For example, a square cylindrical coil etc. may be used. As described later, in order to facilitate detection of the positional deviation of the non-contact power reception device 2, the shapes of the feeding coil 3 and the core 3a of the feeding coil are symmetrical with respect to one plane passing through the central axis thereof. It is preferable to make it a shape.

  Here, as shown in FIG. 2, the central axis of the feeding coil 3 is L0, and a plane including the central axis L0 is a first central cross section S1 passing through the central point O of the feeding coil 3 and the first center A coordinate axis perpendicular to the cross section S1 is taken as an x axis, and a coordinate axis passing through the center point O of the feeding coil 3 and in the plane of the first central cross section S1 is taken as ay axis.

  The detection coil 4 is disposed so as to enclose the feeding coil 3 in a coil ring, and is a coil that detects the approach and displacement directions of the non-contact power reception device 2 and the displacement amount. The detection coil 4 is disposed at a position where the induced current is minimum when there is no power reception coil 30 (described later) of the non-contact power reception device 2. Specifically, for example, when the feeding coil 3 is a cylindrical coil as shown in FIG. 2, the detecting coil 4 is disposed within the first central cross section S1, and the winding axis thereof is the first central cross section S1. It is arranged so as to be in the direction (x-axis direction) perpendicular to.

  FIG. 3 is a diagram showing an example of a magnetic field generated around the feeding coil 3 when the feeding coil 3 is energized in a state where the receiving coil 30 is not in the vicinity of the feeding coil 3. FIG. 3 is a diagram for explanation. In FIG. 3, the feeding coil 3 is a cored cylindrical coil, and an object (such as a casing) around the feeding coil 3 is ignored. The magnetic flux (magnetic line of force) generated by the feeding coil 3 is indicated by a dotted line. In the case of FIG. 3, the magnetic flux produced by the feed coil is plane-symmetrical to the xy plane and rotationally symmetric to the central axis L 0, so that the winding axis of the detection coil 4 is coaxial with the x-axis. Is placed in the first central cross section S1, the current induced in the detection coil 4 is minimized (0 in the ideal case as in FIG. 3). In the actual case, the orientation of the detection coil 4 is determined because the ideal magnetic field distribution as shown in FIG. 3 is not obtained due to the influence of the shape of the feed coil 3 and the object (casing etc.) disposed around it. In this case, the induction current may be measured while changing the inclination of the detection coil 4 in a state in which the feeding coil 3 is AC-energized, and the angle at which the induction current is minimized may be determined.

  In the present embodiment, the non-contact power feeding device 1 includes a slider mechanism (not shown) for translating the feeding coil assembly 6 in the x-axis direction (left and right direction), and the motor 7 performs this slider mechanism. By driving, the feeding coil assembly 6 is moved in the x-axis direction. As the motor 7, a normal stepping motor is used.

  The power supply circuit 10 is a DC stabilized power supply for supplying power for energizing the feeding coil 3, power for driving the motor 7, and power for driving other circuits. The oscillation circuit 11 is a circuit that generates an AC voltage of frequency f when the feeding coil 3 is energized. The conduction control circuit 12 is a circuit that generates a conduction current to be supplied to the power feeding coil 3 by modulating a direct current supplied from the power supply circuit 10 with an alternating voltage generated by the oscillation circuit 11.

  The electromotive force detection circuit 13 is a circuit that detects the intensity of an electromotive voltage (or electromotive current) generated in the detection coil 4. Since the electromotive force (or electromotive current) generated in the detection coil 4 is an alternating current, the electromotive force detection circuit 13 includes a rectification circuit that rectifies this, and the strength of the electromotive voltage (or electromotive current) of the detection coil 4 is It outputs as a detection voltage value (or voltage value which amplified it) V4 after rectification. The positional deviation detection circuit 16 is a circuit that detects the positional deviation amount Δx of the power receiving coil 30 with respect to the feeding coil 3 from the detection voltage value V4 detected by the electromotive force detection circuit 13.

  The phase difference detection circuit 18 has a phase difference Δφ 43 between the phase φ 3 of the voltage (or current) output from the conduction control circuit 12 to the feeding coil 3 and the phase φ 4 of the electromotive voltage (or electromotive current) generated in the detection coil 4. Is a circuit that detects The misalignment direction detection circuit 19 is a circuit that determines the misalignment direction of the power receiving coil 30 with respect to the feeding coil 3 based on whether the phase difference detected by the phase difference detection circuit 18 is positive or negative.

  The movement control circuit 17 performs drive control of the motor 7 so as to minimize the amount of displacement based on the amount of displacement detected by the displacement detection circuit 16 and the direction of displacement detected by the displacement direction detection circuit 19. It is a circuit. The movement control circuit 17 can be configured using a microcomputer or the like.

  On the other hand, the non-contact power reception device 2 includes the power reception coil 30, the rectification circuit 31, and the secondary battery 32. The power receiving coil 30 is a coil for performing magnetic resonance with the power feeding coil 2 and receiving power supply from the power feeding coil when the non-contact power feeding apparatus 2 approaches the non-contact power feeding apparatus 1. The rectifying circuit 31 is a circuit that rectifies an induced current generated in the power receiving coil 30. The secondary battery 32 is a battery which is stored by the direct current output from the rectifier circuit 31.

  The operation of the noncontact power feeding system according to the present embodiment configured as described above will be described below.

(1) Relationship between positional displacement amount and direction of power receiving coil and induced voltage (current) of detection coil In FIG. 4, when the power receiving coil 30 of the non-contact power receiving device 2 approaches the power feeding coil 3 of the non-contact power feeding device 1 It is a schematic diagram showing change of a magnetic field formed near both coils. In FIG. 4, the magnetic flux is indicated by a dotted line. In FIG. 4, the receiving coil 30 sequentially approaches the feeding coil 3 in the order of (d), (c), (b), and (a), and in FIG. 4 (a), the receiving coil 30 and the feeding coil 3 It represents a state of complete resonance. Note that FIG. 4 approximates a direct current magnetic field, and in fact, since the power feeding coil 3 and the power receiving coil 30 are subjected to alternating current conduction, they become alternating magnetic fields, and magnetic flux lines have a somewhat different distribution from that of FIG.

  When the power receiving coil 30 is not present in the vicinity of the feeding coil 3, as shown in FIG. 3, the number of flux linkages linking the detecting coil 4 is substantially zero. Therefore, no induced current is generated in the detection coil 4. When the power receiving coil 30 approaches the power feeding coil 3, the magnetic field around the power feeding coil 3 is disturbed by the power receiving coil 30. As shown in FIG. 4, when the power receiving coil 30 approaches the power feeding coil 3, the magnetic field around the power feeding coil 3 is disturbed by the influence of the induced current induced in the power receiving coil 30 and the core of the power receiving coil 30. When the receiving coil 30 is not coaxial with the feeding coil 3, the number of flux of the linkage flux linking the detecting coil 4 increases due to the disturbance of the magnetic field by the receiving coil 30 (FIGS. b). Thereby, an induced current is generated in the detection coil 4. When the power receiving coil 30 has a positional relationship in which the power receiving coil 30 and the power feeding coil 3 are coaxial (FIG. 4A), the magnetic field around the power feeding coil 3 is symmetrical with respect to the central axis L0. Accordingly, the number of the flux linkages linking the detection coil 4 is substantially zero, and the induced current generated in the detection coil 4 is also substantially zero. Therefore, by detecting the magnitude of the induced current generated in the detection coil 4, it is possible to detect the amount of positional deviation of the power receiving coil 30 with respect to the feeding coil 3.

  Actually, an alternating current was input to the feeding coil 3, and a measurement experiment was performed on the relationship between the position of the receiving coil 30 and the electromotive voltage of the detecting coil 4. FIG. 5 is a perspective view of the feed coil assembly 6 used in the experiment. In the experiment, a feeding coil 3 used was a cylindrical coil in which a coil wire 3b was wound around the cylinder. The coil core 3a of the feeding coil 3 has a rectangular plate-shaped bottom plate portion connected to the lower end of a cylindrical central shaft portion penetrating the coil wire 3b, and further surrounds both sides of the coil wire 3b at both left and right ends of the bottom plate portion. The surrounding wall portion is formed in a projecting shape. FIG. 6 is a diagram (plan view) showing the positional relationship between the feeding coil assembly 6 and the receiving coil 30 in the measurement experiment of the electromotive voltage. 6A shows a state in which the receiving coil 30 is positioned right above the coaxial line of the feeding coil 3 (coaxial with the central axis L0), FIG. 6B shows a state in which the receiving coil 30 is offset to the right of the feeding coil 3; FIG. 6C shows a state in which the power receiving coil 30 is shifted to the left side of the feeding coil 3.

  FIG. 7 shows voltage waveforms of the feeding coil 3, the receiving coil 30, and the detection coil 4 at the measurement positions B and C in FIG. 7A shows the voltage waveform when the power receiving coil 30 is placed at the relative position A (FIG. 6A), and FIG. 7B places the power receiving coil 30 at the relative position B (FIG. 6B). FIG. 7C shows a voltage waveform when the power receiving coil 30 is placed at the relative position C (FIG. 6C). Further, in FIGS. 7A to 7C, the waveform of the channel 1 (lowermost portion) is a voltage waveform input to the feeding coil 3, and the waveform of the channel 2 (second from the bottom) is induced in the power receiving coil 30. The voltage waveform, the waveform of the channel 4 (uppermost part) is a voltage waveform induced in the detection coil 4.

  As shown in FIG. 7, when the power receiving coil 30 is coaxial with the feeding coil 3, no induced voltage is generated in the detecting coil 4 (FIG. 7 (a)). That is, the strength of the induced voltage waveform is minimized. When the power receiving coil 30 is shifted to the left in the x-axis direction, an induced voltage whose phase is advanced by 90 degrees with respect to the voltage waveform input to the feeding coil 3 is generated in the detection coil 4. Conversely, when the power receiving coil 30 is displaced to the right in the x-axis direction, an induced voltage whose phase is delayed by 90 degrees with respect to the voltage waveform input to the feeding coil 3 is generated in the detection coil 4. Therefore, it is possible to detect the positional deviation direction of the receiving coil 30 with respect to the feeding coil 3 by detecting the positive or negative of the phase of the induction voltage induced in the detecting coil 4 with respect to the voltage waveform input to the feeding coil 3 I understand that.

  Whether the phase of the induced voltage waveform of the detection coil 4 is advanced or delayed with respect to the displacement direction of the power reception coil 30 depends on the winding direction of the power supply coil 3 and the power reception coil 30.

(2) Operation of Non-Contact Power Feeding Device 1 Next, the operation of the non-contact power feeding device 1 of FIG. FIG. 8 is a flowchart showing the positional deviation correction control operation of the movement control circuit 17 of the non-contact power feeding device 1. Here, when the power receiving coil 30 is shifted leftward in the x-axis direction with respect to the power feeding coil 3, it is assumed that an induced voltage with a phase advanced by 90 degrees is generated in the detection coil 4.

  First, in step S1, the movement control circuit 17 determines whether the positional deviation amount Δx detected by the positional deviation detection circuit 16 is larger than a predetermined threshold ε. In the case of Δx ≦ ε, the determination operation of step S1 is repeated. If Δx> ε, the process proceeds to the next step S2.

  Next, in step S2, the movement control circuit 17 determines whether the phase difference Δφ 43 detected by the phase difference detection circuit 18 is positive or negative. Here, when Δφ 43 is positive, the movement control circuit 17 rotates the motor 7 by one step in the rotation direction in which the feeding coil assembly 6 moves rightward (S 3), and when Δφ 43 is negative, the movement control circuit 17 The control circuit 17 rotates the motor 7 by one step in the rotation direction in which the feeding coil assembly 6 moves leftward (S4). Then, the process returns to step S1 again.

  By this operation, the feeding coil assembly 6 is controlled in position so that the feeding coil 3 is positioned just below the receiving coil 30 following the position of the receiving coil 30.

  In the present embodiment, it is assumed that among the deviations of the power receiving coil 30 with respect to the feeding coil 3, the deviation in the y direction can be ignored. This assumes, for example, the case where the wheel of the electric wheelchair is placed on a predetermined rail and set at the time of charging, when the non-contact power feeding system of this embodiment is applied to the charger of the electric wheelchair. In this case, the direction along the rail may be the x-axis, and only the positional deviation in the x-axis direction may be considered.

  The energization control circuit 12 intermittently energizes the feeding coil 3 to detect misalignment while the misalignment control is being performed, and the misalignment amount Δx detected by the misalignment detection circuit 16 is Δx. In the case of ≦ ε, switching may be performed so as to continuously energize.

  FIG. 9 is a block diagram showing the configuration of a non-contact power feeding system according to a second embodiment of the present invention. FIG. 10 is a schematic view showing the arrangement of the feeding coil 3 and the detection coils 4a and 4b in FIG. FIG. 11 is a diagram showing a specific configuration example of the feed coil 3 and the detection coils 4a and 4b of FIG.

  In the noncontact power feeding system of the present embodiment, the detection coil 4, the electromotive force detection circuit 13, the displacement detection circuit 16, the phase difference detection circuit 18, and the displacement direction detection circuit 19 of FIG. Provided two each (detection coils 4a and 4b, electromotive force detection circuits 13a and 13b, displacement detection circuits 16a and 16b, phase difference detection circuits 18a and 18b, and displacement direction detection circuits 19a and 19b in FIG. 9). The detection coils 4a and 4b are disposed orthogonal to each other, and a slider mechanism (not shown) for driving the feeding coil assembly 6 enables parallel movement in the y-axis direction in addition to the x-axis. As the motor 7 for driving the slider mechanism, a motor 7a in the x-axis direction and a motor 7b in the y-axis direction are provided, and the movement control circuit 17 detects the misalignment detection circuit 16 and misalignment direction. The difference is that drive control of the two motors 7a and 7b is performed so as to minimize the amount of misalignment based on the amount of misalignment detected by the circuits 19a and 19b and the direction of misalignment in the x-axis and y-axis directions. . Other than that is the same as that of the first embodiment.

  In the feed coil assembly 6 of the present embodiment, as shown in FIGS. 10 and 11, the feed coil 3 and the detection coils 4a and 4b are integrally incorporated. As shown in FIG. 10, the central axis of the feeding coil 3 is L0, and a plane including the central axis L0 is a plane including the first central cross section S1 and the central axis L0, and a plane perpendicular to the first central cross section S1. The second central cross section S2 passes through the central point O of the feed coil 3 and has a coordinate axis perpendicular to the first central cross section S1 as the x axis, and passes through the central point O of the feed coil 3 and the second central cross section S2. Let y be the coordinate axis perpendicular to.

  The detection coils 4a and 4b are both arranged orthogonal to each other so as to enclose the feeding coil 3 in the coil ring, and in a state where there is no power receiving coil 30 (described later) of the non-contact power receiving device 2, induced current is minimum. It is arranged at the position where Specifically, in the case where the feeding coil 3 is a cylindrical coil as shown in FIG. 10, the detecting coil 4a is disposed within the first central cross section S1 in the same manner as the detecting coil 4 of the first embodiment. The axis is oriented so as to be perpendicular to the first central cross section S1 (x-axis direction). The detection coil 4b is disposed within the second central cross section S2 and is oriented such that its winding axis is oriented (y-axis direction) perpendicular to the second central cross section S2.

  In the present invention, the shapes of the feeding coil 3 and the core 3a of the feeding coil are not limited to this, and for example, a square cylindrical coil may be used. As described later, in order to facilitate detection of the positional deviation of the non-contact power reception device 2, the shapes of the feeding coil 3 and the core 3a of the feeding coil are symmetrical with respect to one plane passing through the central axis thereof. It is preferable to make it a shape.

  As described above, in the non-contact power feeding system of the present embodiment, by providing the two detection coils 4 a and 4 b orthogonal to each other, the x-axis direction component and y-axis direction component of the positional deviation of the power receiving coil 30 with respect to the power feeding coil 3 It becomes possible to detect the component. The movement control circuit 17 controls the motors 7a and 7b based on the displacement amounts and directions in two directions (x-axis direction and y-axis direction) detected by the misalignment detection circuits 16a and 16b and the misalignment direction detection circuits 19a and 19b. Can be adjusted to adjust the position of the feeding coil assembly 6 in two directions, and the feeding coil 3 can be moved to the optimum position to perform feeding. The control operation of the movement control circuit 17 may be performed independently in each of the x-axis direction and the y-axis direction, and may be performed in the same process as the process described in FIG. .

  FIG. 12 is a block diagram showing the configuration of a non-contact power feeding system according to a third embodiment of the present invention. FIG. 13 is a schematic view showing the feeding coil assembly 6 in FIG. In the present embodiment, the configuration of the non-contact power reception device 2 is the same as in the first and second embodiments. Moreover, about the non-contact electric power supply apparatus 1, the same code | symbol is attached | subjected about the part similar to Example 2. FIG. The non-contact power feeding device 1 of the present embodiment is different from that of the second embodiment in that a detection coil 5, an electromotive force detection circuit 13c, a phase difference detection circuit 18c, and a resonance frequency control circuit 20 are provided.

  As shown in FIG. 13, the feeding coil assembly 6 of this embodiment is disposed adjacent to the side of the feeding coil 3 in addition to the two orthogonally arranged detection coils 4a and 4b described in the second embodiment. The detection coil 5 coaxial with the detection coil 4b is provided. Here, the winding axis of the detection coil 5 is in a direction perpendicular to the magnetic flux generated by the feeding coil 3 in a state where the receiving coil 30 is not present in the vicinity of the feeding coil 3. Therefore, when the power receiving coil 30 does not exist in the vicinity of the power feeding coil 3, the number of magnetic fluxes linking the detection coil 5 among the magnetic flux generated by the power feeding coil 3 is approximately zero. (Electromotive current) does not occur.

  On the other hand, when the receiving coil 30 approaches in the vicinity of the feeding coil 3, the magnetic field around the feeding coil 3 is disturbed by the influence of the receiving coil 30 (see FIG. 4). It will not be. Therefore, an electromotive voltage (or electromotive current) is generated in the detection coil 5. When the power receiving coil 30 approaches the position coaxial with the power feeding coil 3 right above the power feeding coil 3, as described in the first and second embodiments, the electromotive voltage (or electromotive current) of the detection coils 4a and 4b is substantially zero. It becomes. On the other hand, since the detection coil 5 is provided offset from the center O of the feed coil 3, the number of magnetic fluxes linking the detection coil 5 at this time is not zero, and an electromotive voltage (or electromotive current) is generated. The phase φ5 of this electromotive voltage (or electromotive current) is energized to the feeding coil 3 in the ideal case (when the energizing frequency of the feeding coil 3 matches the resonant frequency between the feeding coil 3 and the receiving coil 30) With respect to the phase φ3 of the current to be

  Therefore, it is determined whether the detection voltage value (or the voltage value obtained by amplifying it) V5 detected by the electromotive force detection circuit 13c is equal to or higher than the predetermined threshold value Vth5. It can be determined whether or not it has approached.

  Further, in an actual non-contact power feeding system, the inductance of the power feeding coil 3 and the power receiving coil 30 changes during a long time due to deterioration with time of the power feeding coil 3 and the power receiving coil 30. Therefore, the phenomenon that the resonance frequency between the feeding coil 3 and the receiving coil 30 deviates from the design value as the use period becomes long is observed. The absolute value of the phase difference Δφ53 = φ5-φ3 of the phase φ5 of the induced current of the detection coil 5 with respect to the phase φ3 of the energizing current of the feed coil 3 shifts from 90 degrees as the energization frequency of the feed coil 3 deviates from the resonance frequency. . Therefore, by checking the phase difference | Δφ 53 |, it is possible to detect the deviation of the energization frequency of the feeding coil 3 with respect to the resonance frequency.

  Therefore, based on the phase difference detected by the phase difference detection circuit 18c, the resonance frequency control circuit 20 sets the frequency of the oscillation circuit 11 so that the phase difference between the phase of the induced voltage V5 and the phase of the feed voltage V3 is 90 degrees. Take control. Specifically, a voltage controlled oscillator (VCO) for the oscillation circuit 11, a phase comparator (PC) for outputting the phase difference as a voltage to the phase difference detection circuit 18c, and an output of the phase comparator for the resonance frequency control circuit 19. A low-pass filter (LPF) that generates a control voltage of the voltage control oscillator may be used to form a frequency negative feedback circuit (Phase Locked Loop: PLL) using VCO, PC, and LPF.

  FIG. 14 is a flowchart showing the misalignment correction control operation of the movement control circuit 17 of the non-contact power feeding device 1 of FIG. 12 and the conduction mode switching operation of the conduction control circuit 12. The positional deviation correction control of the movement control circuit 17 is executed independently in the x-axis direction and the y-axis direction, and FIG. 14A shows only the positional deviation correction control in the x-axis direction. The y-axis direction is also the same as in FIG.

  First, in step S10, the electromotive force detection circuit 13c determines whether or not the detected value V5 of the induced voltage of the detection coil 5 is larger than a predetermined threshold value Vth5. Here, the threshold value Vth5 is a threshold value for determining whether or not an induced voltage (induced current) is generated in the detection coil 5, and is set to a sufficiently small value. In fact, since various objects such as a casing are disposed around the feeding coil 3, even when the receiving coil 30 is not present in the vicinity of the feeding coil 3, the induced voltage of the detection coil 5 (induced voltage The current) can not be completely zero. The threshold value Vth5 is set to prevent an erroneous determination due to the induced voltage (induced current) generated in a noise manner. If V5 <Vth5, it is determined that the power receiving coil 30 is not present in the vicinity of the power feeding coil 3, and the energization control circuit 12 sets the energization mode to the "power feeding standby mode" (S11), and returns to step S10. On the other hand, if V5 ≧ Vth5, the process proceeds to the next step S12.

  Here, the energization modes of the energization control circuit 12 include a “feed standby mode” and a “feed mode”. The “power supply standby mode” is a power supply mode in which the power supply control circuit 12 performs pulse-like power supply intermittently at constant time intervals (for example, 5 seconds interval). In the power supply standby mode, it is energization for the purpose of detecting the presence of the power receiving coil 30 only. On the other hand, the "power supply mode" is a power supply mode in which the power supply control circuit 12 continuously supplies power.

  In step S12, the movement control circuit 17 determines whether or not the positional deviation amount Δx detected by the positional deviation detection circuit 16a is larger than a predetermined threshold value ε. In the case of Δx ≦ ε, after performing the power supply mode shift determination processing (FIG. 14B) described later (S13), the process returns to the determination operation of step S10. If Δx> ε, the process proceeds to the next step S14.

  Next, in step S14, the movement control circuit 17 determines whether the phase difference Δφ43 detected by the phase difference detection circuit 18a is positive or negative. Here, when Δφ 43 is positive, the movement control circuit 17 rotates the motor 7 a by one step in the rotation direction in which the feeding coil assembly 6 moves rightward along the x axis (S 15), and Δφ 43 is negative. In this case, the movement control circuit 17 rotates the motor 7a by one step in the rotational direction in which the feeding coil assembly 6 moves leftward along the x axis (S16). Then, the process returns to step S12 again.

  By this operation, the feeding coil assembly 6 follows the position of the power receiving coil 30 in the x-axis direction, and the position control is performed such that the feeding coil 3 is positioned directly below the power receiving coil 30 in the x-axis direction. Also in the y-axis direction, position adjustment is performed as in FIG.

  The feed mode transition determination process of step S13 is performed according to the flow of FIG. First, the energization control circuit 12 determines whether or not both the positional deviation amount Δx detected by the positional deviation detection circuit 16a and the positional deviation amount Δy detected by the positional deviation detection circuit 16b have become equal to or less than a predetermined threshold ε. In the case of (S21), (Δx ≦ ε∧Δy ≦ ε), the energization control circuit 12 sets the energization mode to the “feed mode”. If not, the "power feeding standby mode" is maintained. As a result, when the feeding coil 3 is at a position immediately below in the x-axis direction and the y-axis direction of the receiving coil 30, feeding is started.

  FIG. 15 is a block diagram showing the configuration of a non-contact power feeding system according to a fourth embodiment of the present invention. In this embodiment, the displacement detection mechanism and the position adjustment mechanism used in the non-contact power feeding device of the second embodiment are applied to the non-contact power receiving device 2 side. Therefore, the same components as in the second embodiment (see FIG. 9) are assigned the same reference numerals and descriptions thereof will be omitted. Moreover, about the non-contact electric power feeding apparatus 1, since it is the same as that of Example 3, an internal structure is abbreviate | omitted. Since power transmission is not performed on the non-contact power reception device 2 side, the power supply circuit 10, the oscillation circuit 11, and the energization control circuit 12 in FIG. 9 are not provided. As described above, by applying the same to the non-contact power reception device 2 in exactly the same manner, it is possible to perform positional deviation detection and position adjustment on the non-contact power reception device 2 side.

  In this embodiment, it is assumed that the non-contact power reception device 2 is applied to an electric car or an electric wheelchair, and a wheel for moving the entire non-contact power reception device 2 and its drive mechanism (motor drive circuit 33 And a motor 34). The wheels are driven by the motor 34 to adjust the position of the non-contact power reception device 2.

  Moreover, although the example which applied the positional offset detection mechanism and the position adjustment mechanism which were used in the non-contact electric power supply apparatus of Example 2 was shown in the present Example at the side of the non-contact power reception apparatus 2, in this invention, non-contact The positional deviation detection mechanism and the positional adjustment mechanism used in the non-contact power feeding device of the third embodiment can also be applied to the power receiving device 2 side.

DESCRIPTION OF SYMBOLS 1 noncontact power feeding device 2 noncontact power receiving device 3 feeding coil 3a coil core 3b coil wire 4, 4a, 4b detecting coil 5 detecting coil 6 feeding coil assembly 7, 7a, 7b motor 10 power supply circuit 11 oscillation circuit 12 conduction control circuit 13, 13a, 13b, 13c EMF detection circuit 16, 16a, 16b Misalignment detection circuit 17 Movement control circuit 18, 18a, 18b, 18c Phase difference detection circuit 19, 19a, 19b Misalignment direction detection circuit 20 Resonant frequency control circuit 30 Power reception Coil 31 Rectifier circuit 32 Secondary battery

Claims (6)

A noncontact power feeding device comprising a feeding coil to which alternating current power is fed, and a noncontacting power receiving coil detachably mounted on the feeding coil and receiving a power supply from the feeding coil in resonance with the feeding coil A contactless power supply device used in a contactless power supply system comprising a power receiving device, comprising:
In a plane of a first central cross section which is a plane including a central axis of the feeding coil, a first detection coil is provided, the winding axis of which is oriented in a direction perpendicular to the first central cross section. ,
The first detection coil is disposed so as to enclose the feeding coil in a coil ring of the first detection coil,
First electromotive force detection means for detecting an intensity of an electromotive voltage or an electromotive current generated in the first detection coil;
First phase difference detection means for detecting a phase difference between a phase of a voltage or current supplied to the feeding coil and a phase of an electromotive voltage or current generated in the first detection coil;
A first positional deviation detection unit that determines presence or absence of positional deviation of the power receiving coil with respect to the power feeding coil by determining a threshold of the strength of the electromotive voltage or electromotive current detected by the first electromotive force detection unit;
First misregistration direction detection means for detecting misregistration direction in the central axis direction (hereinafter referred to as “x-axis direction”) of the first detection coil based on the phase difference detected by the first phase difference detection means And a contactless power supply device characterized by comprising. The direction in which the winding axis is perpendicular to the second central cross section within the plane of the second central cross section which is the plane including the central axis of the feeding coil and perpendicular to the first central cross section Comprising a second detection coil arranged
The second detection coil is disposed so as to enclose the feeding coil in a coil ring of the second detection coil,
A second electromotive force detection unit that detects the intensity of an electromotive voltage or an electromotive current generated in the second detection coil;
Second phase difference detection means for detecting a phase difference between the phase of the voltage or current supplied to the feeding coil and the phase of the electromotive voltage or current generated in the second detection coil;
Second positional deviation detection means for judging presence / absence of positional deviation of the power receiving coil with respect to the power feeding coil by making a threshold judgment on the strength of the electromotive voltage or electromotive current detected by the second electromotive force detecting means;
Second misalignment direction detecting means for detecting misalignment direction of the central axis direction (hereinafter referred to as “y-axis direction”) of the second detection coil based on the phase difference detected by the second phase difference detection means And a non-contact power feeding device according to claim 1. A third detection coil in which a winding shaft is disposed on a side portion of the feeding coil in a direction perpendicular to a magnetic flux generated by the feeding coil in a state where the receiving coil does not approach the feeding coil. When,
Third phase difference detection means for detecting a phase difference between the phase of the voltage or current supplied to the feeding coil and the phase of the electromotive voltage or current generated in the third detection coil;
And resonance frequency control means for controlling the frequency of the voltage or current supplied to the feeding coil such that the phase difference detected by the third phase difference detecting means becomes a predetermined value. The non-contact electric power supply according to claim 1 or 2. Third detecting a magnitude of an electromotive voltage or an electromotive current generated in the third detection coil
EMF detection means of
Presence / absence detection means for determining whether or not the power receiving coil is present in the vicinity of the power feeding coil by determining the threshold of the strength of the electromotive voltage or the electromotive current detected by the third electromotive force detection means; The contactless power supply device according to claim 3, characterized in that: A noncontact power feeding device comprising a feeding coil to which alternating current power is fed, and a noncontacting power receiving coil detachably mounted on the feeding coil and receiving a power supply from the feeding coil in resonance with the feeding coil A noncontact power reception device used in a noncontact power feeding system comprising a power reception device,
In a plane of a first central cross section which is a plane including a central axis of the power receiving coil, a first detection coil is provided, the winding axis of which is oriented in a direction perpendicular to the first central cross section. ,
The first detection coil is disposed so as to enclose the power receiving coil in a coil ring of the first detection coil,
First electromotive force detection means for detecting an intensity of an electromotive voltage or an electromotive current generated in the first detection coil;
First phase difference detection for detecting a phase difference between a phase of voltage or current induced in the power receiving coil by an alternating magnetic field generated by the feeding coil and a phase of electromotive voltage or current generated in the first detection coil Means,
A first positional deviation detection unit that determines presence or absence of positional deviation of the power receiving coil with respect to the power feeding coil by determining a threshold of the strength of the electromotive voltage or electromotive current detected by the first electromotive force detection unit;
First misregistration direction detection means for detecting misregistration direction in the central axis direction (hereinafter referred to as “x-axis direction”) of the first detection coil based on the phase difference detected by the first phase difference detection means And a non-contact power reception device characterized by comprising. The direction in which the winding axis is perpendicular to the second central cross section within the plane of the second central cross section, which is the plane including the central axis of the power receiving coil and perpendicular to the first central cross section Comprising a second detection coil arranged
The second detection coil is disposed so as to enclose the power receiving coil in a coil ring of the second detection coil,
A second electromotive force detection unit that detects the intensity of an electromotive voltage or an electromotive current generated in the second detection coil;
A second phase difference detection that detects a phase difference between a phase of a voltage or current induced in the power receiving coil by an alternating magnetic field generated by the feeding coil and a phase of an electromotive voltage or current generated in the second detection coil Means,
Second positional deviation detection means for judging presence / absence of positional deviation of the power receiving coil with respect to the power feeding coil by making a threshold judgment on the strength of the electromotive voltage or electromotive current detected by the second electromotive force detecting means;
Second misalignment direction detecting means for detecting misalignment direction of the central axis direction (hereinafter referred to as “y-axis direction”) of the second detection coil based on the phase difference detected by the second phase difference detection means And a non-contact power reception device according to claim 5.

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