JP2010226889A - Non-contact power supply device and electric vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently transmit power by having a large mutual inductance between coils even when a relative position between a primary coil and a secondary coil is changed. <P>SOLUTION: The secondary coil 21 is constituted of a plurality of split coil 21a, 21b, 21c, and coil polarity inversion circuits 24a, 24b, 24c are provided which can individually switch polarities of the respective split coils 21a, 21b, 21c. A controller 25 controls operations of the coil polarity inversion circuits 24a, 24b, 24c in accordance with the polarities of the interlinkage magnetic flux which interlink with the respective split coils 21a, 21b, 21c constituting the secondary coil 21 during energization to the primary coil 14, so that reduction in the total amount of the interlinkage magnetic flux is suppressed by restraining the magnetic flux having different polarities from being cancelled by interlinkage with the secondary coil 21, even when the relative position between the primary coil 14 and the secondary coil 21 is changed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electromagnetic induction type non-contact power supply device and an electric vehicle.

  2. Description of the Related Art Conventionally, an electromagnetic induction type non-contact power feeding device is known in which a primary coil on a power feeding side and a secondary coil on a power receiving side are magnetically coupled to transmit power in a non-contact manner from the power feeding side to the power receiving side (for example, (See Patent Document 1). In the non-contact power feeding device described in Patent Document 1, even if the equivalent resistance component of the load on the power receiving side changes, the power factor supplied from the high frequency power supply unit on the power feeding side is maintained and efficient power transmission is performed. In order to be able to do this, a resistance component of the load is detected by a resistance detection circuit, and the frequency of the high-frequency power generated by the high-frequency power supply unit is controlled in accordance with the detected resistance component of the load.

JP 2002-272134 A

  The technology described in Patent Document 1 realizes efficient power transmission by keeping the power factor high by frequency control of power supply power on the premise that there is no change in the relative position of the primary coil and the secondary coil. . For this reason, this technology is used in applications where the relative positions of the primary and secondary coils are expected to change, for example, in applications where electric power is transmitted from a power supply facility of an electric station to an electric vehicle and the battery is charged. In such a case, when the stop position of the electric vehicle is shifted, the mutual inductance between the coils is reduced due to the shift of the relative position of the primary coil and the secondary coil, and efficient power transmission cannot be performed. is there.

  The present invention was devised in view of the problems of the prior art as described above, and greatly increases the mutual inductance between the coils even when the relative position of the primary coil and the secondary coil changes. It is an object of the present invention to provide a non-contact power feeding device capable of performing efficient power transmission and an electric vehicle using the same.

  According to the present invention, the secondary coil of the power receiving circuit is configured by a plurality of divided coils, and the polarity of the plurality of divided coils can be individually switched according to the polarity of the magnetic flux linked to each divided coil. Thus, the above-described problem is solved.

  According to the present invention, the polarity of the plurality of divided coils constituting the secondary coil is switched in accordance with the polarity of the magnetic flux interlinking with each divided coil, so that the deviation of the relative position of the secondary coil with respect to the primary coil becomes 2 It is possible to effectively suppress the disadvantage that the interlinkage magnetic fluxes having different polarities cancel each other in the secondary coil and the total amount of interlinkage magnetic fluxes is reduced. Therefore, even when the relative position between the primary coil and the secondary coil changes, it is possible to increase the mutual inductance between the primary coil and the secondary coil and perform efficient power transmission.

It is a block diagram which shows schematic structure of the non-contact electric power supply to which this invention is applied. It is a schematic diagram explaining the relative positional relationship of a primary coil and a secondary coil at the time of comprising a secondary coil with a single coil. It is a graph which shows the relationship between the relative position of a primary coil and a secondary coil, and the magnetic survey linked to a secondary coil when a fixed DC current is supplied to a primary coil. It is a graph which shows the relationship between the relative position of a primary coil and a secondary coil, and the magnetic survey linked to a secondary coil when a fixed DC current is supplied to a primary coil. It is a figure which shows the position of the secondary coil in the magnetic field which a primary coil generate | occur | produces when the deviation | shift amount of the relative position of a primary coil and a secondary coil is zero. It is a figure which shows the position of the secondary coil in the magnetic field which a primary coil generate | occur | produces when the deviation | shift amount of the relative position of a primary coil and a secondary coil is 300 mm. It is a figure which shows the position of the secondary coil in the magnetic field which a primary coil generate | occur | produces when the deviation | shift amount of the relative position of a primary coil and a secondary coil is 500 mm. It is the schematic diagram which showed simply the influence on the linkage magnetic flux of a secondary coil by the shift | offset | difference of a relative position with respect to a primary coil. It is a figure explaining operation | movement of the polarity inversion switch with which a coil polarity inversion circuit is provided. It is a schematic diagram which shows an example of the mechanism which detects the relative position of a primary coil and a secondary coil. It is a schematic diagram explaining each pattern when patterning the relative position of a primary coil and a secondary coil. It is a figure which shows an example of the correspondence map showing the correspondence of the relative position of a primary coil and a secondary coil, and the polarity of each division | segmentation coil. A pulse voltage applying unit that applies a weak pulse voltage for inspection to the primary coil, and a current sensor that detects an induced current flowing in each divided coil of the secondary coil when the pulse voltage for inspection is applied to the primary coil. It is a schematic diagram which shows the structure provided. It is a figure which shows an example of the current waveform of each division | segmentation coil detected by a current sensor, when the weak test pulse is applied to a primary coil from a pulse voltage application part. It is a schematic diagram which shows the structure which provided the power meter which measures the electric energy transmitted from the electric power feeding side to the receiving side. It is a schematic diagram explaining the example which made the total value of the diameter in the coil shear direction of the some split coil which comprises a secondary coil larger than the diameter in the coil shear direction of a primary coil. Example in which the positions of both end portions of the primary coil coincide with the positions of the end portions of any of the divided coils constituting the secondary coil in a state where there is no deviation in the relative position between the primary coil and the secondary coil. FIG. FIG. 6 is a schematic diagram for explaining that the influence of magnetic flux wrapping at the end of the primary coil can be reduced even when the relative positions of the primary coil and the secondary coil are shifted by reducing the diameters of the split coils on the left and right ends. is there. It is a schematic diagram which shows a mode that electric power feeding is performed with respect to an electric vehicle in an electric station. It is a graph explaining the effect of comprising a secondary coil by a some division | segmentation coil and being able to switch the polarity of these some division | segmentation coils separately. It is a schematic diagram explaining the structure of the coil of Example 1, the comparative example 1, Example 2, and the comparative example 2 in FIG.

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

  FIG. 1 is a configuration diagram showing a schematic configuration of a non-contact power feeding apparatus to which the present invention is applied. The non-contact power feeding device of the present embodiment is an electromagnetic induction type non-contact type in which the primary coil 14 on the power feeding side and the secondary coil 21 on the power receiving side are magnetically coupled to transmit power from the power feeding side to the power receiving side in a non-contact manner. In particular, the power supply device is configured as a device for transmitting electric power from a power supply facility of an electric station to an electric vehicle and charging a battery 23 of the electric vehicle.

  In this non-contact power supply device, the power supply side is realized as a fixed power supply facility installed in an electric station, and a commercial frequency AC power supply unit 11, a rectifier 12 that converts alternating current from the AC power supply unit 11 into direct current, and a rectifier The inverter 13 converts the 12 DC outputs into arbitrary AC, and the primary coil 14 to which the harmonic current generated by the inverter 13 is energized.

  On the other hand, the power receiving side is realized as an in-vehicle facility installed in an electric vehicle, and a secondary coil 21 that generates an induced electromotive force by being magnetically coupled to the primary coil 14 on the power feeding side, and an induced electromotive force generated in the secondary coil 21. A rectifier 22 that converts electric power into direct current and a battery 23 that is charged by the direct current output of the rectifier 22 are provided. In particular, in the non-contact power feeding device according to the present embodiment, the secondary coil 21 on the power receiving side includes a plurality of divided coils 21 a, 21 b, and 21 c, and each divided coil 21 a that configures these secondary coils 21. , 21b, 21c are connected to coil polarity inversion circuits 24a, 24b, 24c capable of individually switching the polarities of the divided coils 21a, 21b, 21c, and the operation of these coil polarity inversion circuits 24a, 24b, 24c. A controller 25 is provided for controlling the above.

  In a non-contact power feeding apparatus that transmits power to an electric vehicle by magnetic coupling between a primary coil 14 on a power feeding side that is a fixed facility and a secondary coil 21 on a power receiving side that is installed in the electric vehicle, the stop position of the electric vehicle It is assumed that the relative position of the primary coil 14 and the secondary coil 21 changes due to the deviation from the predetermined power feeding position. Thus, in order to enable efficient power transmission even in a situation where the relative position of the primary coil 14 and the secondary coil 21 changes, the non-contact power feeding device of the present embodiment uses the secondary coil 21. Is composed of a plurality of split coils 21a, 21b, 21c so that the polarities of the plurality of split coils 21a, 21b, 21c can be individually switched. Hereinafter, the superiority of the above-described configuration characteristic of the present embodiment will be described by comparison with the case where the secondary coil 21 is configured by a single coil.

  FIG. 2 is a schematic diagram for explaining the relative positional relationship between the primary coil 14 and the secondary coil 21 when the secondary coil 21 is formed of a single coil, and is installed on the road surface as a power supply facility for an electric station. It is a model figure supposing the case where the primary coil 14 and the secondary coil 21 installed in the vehicle body bottom part of an electric vehicle are seen in the direction parallel to a road surface. In FIG. 2, the relative position of the primary coil 14 and the secondary coil 21 changes according to the stop position of the electric vehicle in the left-right direction of the figure, which is a direction parallel to the road surface. Hereinafter, this direction is referred to as a “coil shear direction”, and X is the amount of deviation of the relative position between the primary coil 14 and the secondary coil 21 in the coil shear direction. Note that Z in FIG. 2 is the distance (gap) between the opposed surfaces of the primary coil 14 and the secondary coil 21 and is a value determined according to the minimum ground clearance of the electric vehicle.

  Using the model diagram shown in FIG. 2, the magnetic survey linked to the secondary coil 21 when a constant DC current is applied to the primary coil 14 is shown in relation to X and Z in FIG. FIG. 3 and 4, the horizontal axis indicates the magnitude of the relative displacement X of the primary coil 14 and the secondary coil 21 in the coil shear direction, and the vertical axis indicates the secondary coil when the primary coil 14 is energized. 21 shows the amount of magnetic flux interlinking. 3 represents the upward magnetic flux in FIG. 2, the − side represents the downward magnetic flux in FIG. 2, and the vertical axis in FIG. 4 represents the absolute value of the amount of magnetic flux interlinked with the secondary coil 21. ing.

  As can be seen from FIG. 3 and FIG. 4, when the relative position in the coil shearing direction is not shifted between the primary coil 14 and the secondary coil 21, the secondary coil is energized by energization of the primary coil 14 in the vicinity of X = 0. A large amount of magnetic flux interlinks with the coil 21, but when the secondary coil 21 is composed of a single coil, the amount of magnetic flux interlinked with the secondary coil 21 decreases rapidly as X increases, When a certain value is reached (X = 300 mm in the examples of FIGS. 3 and 4), the amount of magnetic flux linked to the secondary coil 21 becomes zero. When X further increases, the polarity of the interlinkage magnetic flux is reversed and the magnetic flux interlinks in the negative direction. However, the interlinkage magnetic flux has a peak at a certain value (X = 500 mm in the examples of FIGS. 3 and 4). Gradually decreases. Such a relationship has the same tendency even if the distance Z between the opposed surfaces of the primary coil 14 and the secondary coil 21 changes.

  The above phenomenon is based on the position of the secondary coil 21 in the magnetic field generated by energization of the primary coil 14 due to the change in the relative position of the primary coil 14 and the secondary coil 21 in the coil shear direction. It's easy to understand when it comes to.

  5 to 7 are views showing the position of the secondary coil 21 with respect to the magnetic flux distribution generated by energization of the primary coil 14, and FIG. 5 shows the case of X = 0 in the examples of FIGS. FIG. 6 shows the position of the secondary coil 21 in the magnetic field generated by the primary coil 14, and FIG. 6 shows the secondary coil in the magnetic field generated by the primary coil 14 when X = 300 mm in the examples of FIGS. FIG. 7 shows the position of the secondary coil 21 in the magnetic field generated by the primary coil 14 when X = 500 mm in the example shown in FIGS. 3 and 4. 5 to 7, the distance Z between the opposed surfaces of the primary coil 14 and the secondary coil 21 is 50 mm.

  As shown in FIG. 5, when there is no shift in the relative position in the coil shear direction between the primary coil 14 and the secondary coil 21 (X = 0), the upward magnetic flux indicated by the arrow A in the figure is The secondary coil 21 is uniformly linked, and the amount of magnetic flux linked to the secondary coil 21 is increased. On the other hand, as shown in FIG. 6, when X = 300 mm, the upward magnetic flux indicated by arrow A in the figure and the downward magnetic flux indicated by arrow B in the figure are mixed in the secondary coil 21, and these upwards Since the magnetic flux and the downward magnetic flux are canceled, as a result, the amount of magnetic flux linked to the secondary coil 21 becomes zero. That is, this state is a state where power cannot be transmitted. Further, as shown in FIG. 7, when X = 500 mm, all the magnetic fluxes linked to the secondary coil 21 become a downward magnetic flux indicated by an arrow B in the figure, and the polarity is reversed.

  FIG. 8 is a schematic diagram simply showing the influence on the interlinkage magnetic flux of the secondary coil 21 due to the displacement of the relative position with respect to the primary coil 14. As shown in FIG. 8A, if the relative position in the coil shear direction is not shifted between the primary coil 14 and the secondary coil 21, the magnetic flux generated by energization of the primary coil 14 is transferred to the secondary coil 21. Although they are linked uniformly, as shown in FIG. 8B, when the relative position is shifted, the polarity of a part of the secondary coil 21 is affected by the influence of the magnetic flux around the end of the primary coil 14. However, different magnetic fluxes are interlinked and canceled, and the total interlinkage magnetic flux amount is reduced. Therefore, in the non-contact power feeding device of the present embodiment, as shown in FIG. 8C, the secondary coil 21 is exemplified by a plurality of divided coils 21a, 21b, 21c (here, the number of divided coils is three). And the coil polarity of each of the divided coils 21a, 21b, and 21c can be switched according to the polarity of the magnetic flux interlinking with each of the divided coils 21a, 21b, and 21c. Even if the relative position of the secondary coil 21 changes, the mutual inductance between the primary coil 14 and the secondary coil 21 can be increased so that the reduction of the total interlinkage magnetic flux in the secondary coil 21 is suppressed. In addition, efficient power transmission can be performed from the primary side (power feeding side) to the secondary side (power receiving side).

  In the non-contact power feeding device of the present embodiment, each of the divided coils 21a, 21b, and 21c constituting the secondary coil 21 is configured as an electrically independent coil, and as shown in FIG. It arrange | positions so that it may adjoin without overlapping in a coil shear direction. In this example, the number of divisions of the secondary coil 21 (the number of division coils) is described as three. However, the number of divisions of the secondary coil 21 is not particularly limited, and an assumed relative position shift is possible. The optimum number may be selected depending on the amount, efficiency of required power transmission, and cost.

  In the contactless power supply device of the present embodiment, the polarities of the divided coils 21a, 21b, and 21c constituting the secondary coil 21 are individually switched by the coil polarity reversing circuits 24a, 24b, and 24c. That is, as shown in FIG. 1, a coil polarity reversing circuit 24a is connected to the split coil 21a, a coil polarity reversing circuit 24b is connected to the split coil 21b, and a coil polarity reversing circuit 24c is connected to the split coil 21c. It is set as the structure connected in series. Each coil polarity reversing circuit 24a, 24b, 24c has a polarity reversing switch as shown in FIG. 9, and the polarity reversing switch operates as shown in FIG. The coil polarity is switched to the minus side by operating the polarity as shown in FIG. 9B.

  The controller 25 divides each divided coil 21a, 21b, 21c according to the polarity of each interlinkage magnetic flux interlinked with each divided coil 21a, 21b, 21c constituting the secondary coil 21 when the primary coil 14 is energized. The operation of the coil polarity inverting circuits 24a, 24b, and 24c connected to is controlled. Here, the polarity of the magnetic flux linked to each of the divided coils 21a, 21b, and 21c constituting the secondary coil 21 varies depending on the relative position between the primary coil 14 and the secondary coil 21, as described above. It is. Therefore, if a mechanism for detecting the relative position between the primary coil 14 and the secondary coil 21 is provided, the controller 25 performs the operation of the coil polarity inversion circuits 24a, 24b, and 24c based on the detection result of the relative position. It becomes possible to control appropriately.

  FIG. 10 is a schematic diagram illustrating an example of a mechanism for detecting a relative position between the primary coil 14 and the secondary coil 21. The relative position detection mechanism shown in FIG. 10 reads the position detection pattern 31 provided on the upper surface of the primary coil 14 (the surface facing the secondary coil 21) installed near the center of the secondary coil 21. By reading with the sensor 32, the relative position of the secondary coil 21 with respect to the primary coil 14 is detected. In the non-contact power feeding device of this embodiment, by providing such a relative position detection mechanism and inputting the output of the reading sensor 32 to the controller 25, the relative position between the primary coil 14 and the secondary coil 21, that is, 2 The polarity of each of the divided coils 21a, 21b, and 21c can be appropriately switched according to the polarity of each magnetic flux that is linked to each of the divided coils 21a, 21b, and 21c constituting the next coil 21.

  Here, a specific example of a method for controlling the operation of the coil polarity inversion circuits 24a, 24b, and 24c based on the relative positions of the primary coil 14 and the secondary coil 21 will be described with reference to FIGS. explain.

  When the secondary coil 21 is composed of three divided coils 21a, 21b, and 21c, the relative positions of the primary coil 14 and the secondary coil 21 are set to, for example, four patterns shown in FIGS. Classify. Pattern 1 shown in FIG. 11A is a state in which there is no deviation in the relative positions of the primary coil 14 and the secondary coil 21 in the coil shear direction. Pattern 2 shown in FIG. 11B is a state in which the relative position in the coil shear direction is slightly shifted and the end of the primary coil 14 is located in the region of the split coil 21a on the left side in the drawing. Pattern 3 shown in FIG. 11C is a state in which the relative position in the coil shearing direction is further shifted and the end of the primary coil 14 is located in the region of the central divided coil 21b. The pattern 4 in FIG. 11D is a state in which the relative position in the coil shear direction is further greatly shifted and the end of the primary coil 14 is located in the region of the split coil 21c on the right side in the drawing.

  When the relative position between the primary coil 14 and the secondary coil 21 is the pattern 1, the secondary coil 21 is configured by setting all the divided coils 21a, 21b, and 21c constituting the secondary coil 21 to the plus side. The total amount of interlinkage magnetic flux linked to Further, when the relative position of the primary coil 14 and the secondary coil 21 is pattern 2, the secondary coil 21a and the split coil 21c can be set to the positive side by setting the polarity of the split coil 21a to the negative side and the polarity of the split coil 21b and the split coil 21c to the secondary side. The total interlinkage magnetic flux amount interlinking with the coil 21 is maximized. Further, when the relative position of the primary coil 14 and the secondary coil 21 is pattern 3, the secondary coil 21a and the split coil 21b are set to the negative side by setting the polarity of the split coil 21a and the split coil 21b to the positive side. The total interlinkage magnetic flux amount interlinking with the coil 21 is maximized. Further, when the relative position between the primary coil 14 and the secondary coil 21 is the pattern 4, the total polarity linked to the secondary coil 21 is set by setting all the polarities of the divided coils 21a, 21b, and 21c to the negative side. The amount of flux linkage is maximized.

  The relationship between the relative position of the primary coil 14 and the secondary coil 21 as described above and the polarity of each of the divided coils 21a, 21b, and 21c constituting the secondary coil 21 corresponding thereto is as shown in FIG. The correspondence map is stored in the internal memory of the controller 25 or the like. Thus, the controller 25 refers to the correspondence map, and based on the relative positions of the primary coil 14 and the secondary coil 21 detected by the relative position detection mechanism described above, the coil polarity reversing circuits 24a, 24b, By appropriately controlling the operation of 24c, the polarity of each of the divided coils 21a, 21b, and 21c can be appropriately switched so that the magnetic flux linked to the secondary coil 21 increases. The relationship between the relative positions of the primary and secondary coils and the polarity of each divided coil varies depending on the characteristics of the non-contact power feeding device, such as the number of divided coils and the size of each divided coil relative to the primary coil. For this reason, a map is created and stored in advance by obtaining an optimum correspondence by experiments or calculations using an actual machine.

  Next, another example of a method for controlling the switching operation of the coil polarity inverting circuits 24a, 24b, and 24c will be described.

  FIG. 13 shows a pulse voltage application unit 41 that applies a weak inspection pulse voltage to the primary coil 14, and each divided coil 21a that constitutes the secondary coil 21 when the inspection pulse voltage is applied to the primary coil 14. , 21b, 21c is a schematic diagram showing a configuration provided with current sensors 42a, 42b, 42c for detecting induced currents flowing in the current. When a weak inspection pulse is applied to the primary coil 14 from the pulse voltage application unit 41, an induced current flows in each of the divided coils 21a, 21b, and 21c constituting the secondary coil 21, but the induced current The polarity and amplitude change according to the relative position of each divided coil 21a, 21b, 21c with respect to the primary coil 14. Therefore, if the outputs of the current sensors 42a, 42b, and 42c that detect the induced currents flowing through the divided coils 21a, 21b, and 21c are input to the controller 25, the polarities of the divided coils 21a, 21b, and 21c are optimized. In addition, the operations of the coil polarity inverting circuits 24a, 24b, and 24c can be appropriately controlled.

  For example, when a weak inspection pulse is applied from the pulse voltage application unit 41 to the primary coil 14, a waveform as shown in FIG. 14A is obtained as a current waveform of the split coil 21a detected by the current sensor 42a. 14 (b) is obtained as the current waveform of the split coil 21b detected by the current sensor 42b, and the current waveform of the split coil 21c detected by the current sensor 42c is shown in FIG. 14 (c). When the waveform as shown is obtained, the total interlinkage magnetic flux interlinking with the secondary coil 21 is controlled by controlling the operation of the coil polarity inversion circuits 24a, 24b, 24c so that only the polarity of the divided coil 21a is inverted. The amount can be increased.

  FIG. 15 is a schematic diagram illustrating a configuration in which a power meter 50 that measures the amount of power transmitted from the power feeding side to the power receiving side is provided. The output of the power meter 50 is the maximum in the state in which power transmission is most efficiently performed from the power feeding side to the power receiving side unless the AC for power transmission passing through the primary coil 14 on the power feeding side has changed. Become. Therefore, if the output of the power meter 50 is input to the controller 25, the combination of the polarities of the divided coils 21a, 21b, and 21c constituting the secondary coil 21 is made minute by operating the coil polarity inversion circuits 24a, 24b, and 24c. By monitoring the output of the power meter 50 while sequentially switching over time, it is possible to search for a combination of the polarities of the split coils 21a, 21b, and 21c that can perform the most efficient power transmission from the power feeding side to the power receiving side. . When a combination of the polarities of the split coils 21a, 21b, and 21c that maximizes the output of the power meter 50 is searched, the operations of the coil polarity inversion circuits 24a, 24b, and 24c are controlled so as to be the combinations. The total amount of interlinkage magnetic flux interlinking with the secondary coil 21 can be increased. In addition, what is necessary is just to use what is provided for normal electric power transmission control in this kind of non-contact electric power feeder as the power meter 50. FIG.

  By the way, in the non-contact electric power feeder of this embodiment demonstrated above, the total value of the diameter in the coil shear direction of the some split coil 21a, 21b, 21c which comprises the secondary coil 21 is the coil shear direction of the primary coil 14. The position of the coil end portion of the primary coil 14 and the position of the end portions of the split coils 21a and 21c at both the left and right ends are substantially the same as the diameter of the coil. Is the same configuration. However, in order to increase the mutual inductance between the coils even when the relative position between the primary coil 14 and the secondary coil 21 is shifted, as shown in FIG. It is effective to make the total value L1 of the diameters of the divided coils 21a, 21b, and 21c in the coil shear direction larger than the diameter L2 of the primary coil 14 in the coil shear direction.

  However, in the configuration of the secondary coil 21 shown in FIG. 16, when the relative positions of the primary coil 14 and the secondary coil 21 are not displaced, the position of the coil end of the primary coil 14 and the split coil Since the positions of the end portions of 21a and 21c do not coincide with each other, even if there is no relative displacement, a part of the interlinkage magnetic flux is canceled by the divided coils 21a and 21c due to the surrounding of the magnetic flux, and the total interlinkage magnetic flux The amount decreases. Therefore, in order to avoid the influence of such magnetic flux wrapping, the coil of the primary coil 14 is not displaced in the relative position between the primary coil 14 and the secondary coil 21 as shown in FIG. Secondary so that the positions of both ends in the shear direction coincide with the positions of the ends in the coil shear direction of any of the split coils (split coils 21a and 21c in the example of FIG. 17) constituting the secondary coil 21. It is desirable to determine the number of split coils that constitute the coil 21 and the arrangement thereof.

  Further, even when the configuration shown in FIG. 17 is used, if the relative position between the primary coil 14 and the secondary coil 21 is deviated, the interlinkage magnetic flux is canceled by the split coils 21d and 21e at the left and right ends. Become. The cancellation of the interlinkage magnetic flux in the split coils 21d and 21e at the left and right ends is effectively suppressed by reducing the diameter in the coil shear direction of the split coils 21d and 21e at the left and right ends, as shown in FIG. be able to. That is, the cancellation of the interlinkage magnetic flux generated in the split coils 21d and 21e at the left and right ends is due to the influence of the magnetic flux around the coil end of the primary coil 14, as described above. Therefore, as shown in FIG. 18B, when the diameters of the split coils 21d and 21e at the left and right ends in the coil shear direction are large, the influence of the magnetic flux is also increased. On the other hand, as shown in FIG. 18 (a), the diameters of the split coils 21d and 21e at the left and right ends in the coil shear direction are made equal to or smaller than the diameters of the split coils 21a, 21b and 21c other than the ends in the coil shear direction. If so, it becomes possible to reduce the influence of the magnetic flux wrapping around the end portion of the primary coil 14 and to make it difficult to cancel the interlinkage magnetic flux. In addition, since this characteristic is a characteristic depending on the amount of relative displacement between the primary coil 14 and the secondary coil 21 and the distance (gap) between the opposed surfaces of the primary coil 14 and the secondary coil 21, It is desirable that the size and number of the divided coils to be set are set to optimum values according to the relative positional deviation amount assumed in the non-contact power feeding device and the distance between the opposing surfaces.

  By the way, as described above, the contactless power supply device of the present embodiment is configured as a device for transmitting power from the power supply facility of the electric station to the electric vehicle and charging the battery 23, as shown in FIG. Further, the primary coil 14 on the power feeding side is installed on the road surface R, and the secondary coil 21 on the power receiving side is installed on the bottom of the vehicle body of the electric vehicle V. Here, the electric station is usually provided with a wheel retainer 60 for stopping the electric vehicle V at a predetermined power supply position, and the electric vehicle V is fed with the rear wheel in contact with the wheel retainer 60. Is often done. For this reason, in the front-rear direction of the electric vehicle V, the relative position between the primary coil 14 and the secondary coil 21 does not change so much, and the relative position between the primary coil 14 and the secondary coil 21 shifts. This is mainly in the vehicle width direction of the electric vehicle V (direction perpendicular to the paper surface of FIG. 19). Therefore, it is desirable that the divided coils constituting the secondary coil 21 be arranged adjacent to each other without overlapping in the vehicle width direction of the electric vehicle V.

  FIG. 20 is a diagram illustrating a characteristic configuration of the present embodiment, that is, an effect when the secondary coil 21 is configured by a plurality of divided coils and the polarities of the plurality of divided coils can be individually switched. And the relative displacement X between the primary coil 14 and the secondary coil 21 and the interlinkage magnetic flux interlinking with the secondary coil 21 in Example 1, Comparative Example 1, Example 2, and Comparative Example 2. This is a graph of the results obtained by calculating the relationship. In the first embodiment, as shown in FIG. 21A, the secondary coil 21 is composed of three divided coils 21a, 21b, and 21c, and the total diameter of the divided coils 21a, 21b, and 21c is calculated. This is an example in which the diameter of the primary coil 14 is substantially equal. In the first comparative example, as shown in FIG. 21B, the secondary coil 21 is constituted by a single coil, and the secondary coil 21 This is an example in which the diameter of the coil is substantially equal to the diameter of the primary coil 14. In the second embodiment, as shown in FIG. 21C, the secondary coil 21 is composed of four divided coils 21a, 21b, 21c, and 21d, and the diameters of the divided coils 21a, 21b, 21c, and 21d. Is a case where the total value is made larger than the diameter of the primary coil 14, and in Comparative Example 1, the secondary coil 21 is configured by a single coil as shown in FIG. In this example, the diameter of the secondary coil 21 is larger than the diameter of the primary coil 14.

  As can be seen from the calculation results shown in FIG. 20, the interlinkage magnetic flux linked to the secondary coil 21 decreases as the relative positional deviation amount X between the primary coil 14 and the secondary coil 21 increases. In Example 2 and Example 2, it is possible to temporarily increase the flux linkage by switching the polarity of the split coil that constitutes the secondary coil 21, and the chain caused by relative positional deviation compared to Comparative Example 1 and Comparative Example 2. A decrease in the magnetic flux can be suppressed. Further, in Comparative Example 1 and Comparative Example 2, there is a point where the interlinkage magnetic flux interlinking with the secondary coil 21 becomes 0 (a point where power transmission cannot be performed). In Example 1 and Example 2, this is the case. There is no longer any point where the flux linkage becomes zero.

  As described above with reference to specific examples, according to the non-contact power feeding device of the present embodiment, the secondary coil 21 is configured by a plurality of divided coils, and the polarities of the plurality of divided coils are individually switched. As a result, when the magnetic flux generated by energizing the primary coil 14 on the power feeding side is linked to the secondary coil 21, the polarity is changed in the secondary coil 21 due to the displacement of the relative position with respect to the primary coil 14. It is possible to avoid a phenomenon in which different magnetic fluxes are linked and consequently the total flux linkage is reduced. Therefore, even when the relative position of the primary coil 14 and the secondary coil 21 changes, the mutual inductance between the coils can be increased, and power transmission from the power feeding side to the power receiving side can be performed efficiently. Further, since the magnetic fluxes having different polarities in the secondary coil 21 are completely canceled out and the phenomenon that the interlinkage magnetic flux becomes equivalently 0 can be avoided, the relative relationship between the primary coil 14 and the secondary coil 21 can be avoided. Even in applications in which the position changes relatively greatly, stable power transmission is possible.

  Further, according to the non-contact power feeding device of the present embodiment, a relative position detection mechanism that detects the relative position between the primary coil 14 and the secondary coil 21 is provided, and the controller 25 is detected by the relative position detection mechanism. By controlling the operation of the coil polarity inversion circuit based on the relative position between the coils, the polarity of each divided coil constituting the secondary coil 21 is appropriately switched, and the total interlinkage flux interlinking with the secondary coil 21 The amount can be increased. Furthermore, in this case, since the polarity of the split coil can be switched in a short time, power can be efficiently transmitted to the electric vehicle, particularly in applications where the electric vehicle is instantaneously powered while moving. It can be carried out.

  Further, according to the contactless power supply device of the present embodiment, when a weak pulse voltage is applied to the primary coil 14, the induced current flowing in each divided coil is detected by the current sensor, and the polarity and amplitude of the current waveform are detected. Based on this, the controller 25 controls the operation of the coil polarity reversing circuit so that the polarity of each of the divided coils constituting the secondary coil 21 is appropriately switched, and the total amount of interlinkage magnetic flux linked to the secondary coil 21 is increased. can do. Furthermore, in this case, since it is not necessary to provide a mechanism for detecting the relative position between the primary coil 14 and the secondary coil 21, the configuration can be simplified, and an alternating current for power transmission is actually energized. Since the polarity of the split coil can be switched before, there is little loss.

  Further, according to the non-contact power feeding device of the present embodiment, the power meter 50 measures the amount of power transmitted from the power feeding side to the power receiving side when alternating current is supplied to the primary coil 14, and the controller 25 performs the secondary coil 21. The polarity combinations of the split coils that maximize the output of the power meter 50 are searched while sequentially switching the combinations of the polarities of the split coils that make up the power by minute time, and the operation of the coil polarity inversion circuit is controlled so as to be the combination. By doing so, the total amount of interlinkage magnetic flux interlinking with the secondary coil 21 can be increased. Furthermore, in this case, since the polarity of the split coil can be appropriately switched using the power meter 50 originally provided for power transmission control, the apparatus configuration can be further simplified.

  Further, according to the non-contact power feeding device of the present embodiment, each divided coil constituting the secondary coil 21 is adjacent to the primary coil 14 without overlapping in the coil shear direction, which is the direction in which the relative position changes. By arranging in such a manner, the magnetic flux can be captured without waste by the secondary coil 21 while using a plurality of coils.

  Further, according to the non-contact power feeding device of the present embodiment, the total value of the diameters of the plurality of split coils constituting the secondary coil 21 in the coil shear direction is made larger than the diameter of the primary coil 14 in the coil shear direction. Thus, even when the relative position of the primary coil 14 and the secondary coil 21 changes, the rate at which the mutual inductance between these coils decreases can be reduced.

  Moreover, according to the non-contact power feeding device of the present embodiment, the total value of the diameters of the plurality of split coils constituting the secondary coil 21 in the coil shear direction is made larger than the diameter of the primary coil 14 in the coil shear direction. In this case, the position of one end of the split coil constituting the secondary coil 21 in a state where the relative positional deviation between the primary coil 14 and the secondary coil 21 is zero is the position of the end of the primary coil 14. By making them coincide with each other, it is possible to effectively avoid the disadvantage that the total interlinkage magnetic flux of the secondary coil 21 is reduced due to the influence of the magnetic flux wrapping around the end of the primary coil 14 in a state where there is no relative displacement. Therefore, efficient power transmission can be performed.

  Moreover, according to the non-contact electric power feeder of this embodiment, the diameter of the divided coil located in both ends among the plurality of divided coils constituting the secondary coil 21 is made equal to or smaller than the diameter of the divided coils other than both ends. Thus, it is possible to alleviate the influence of the magnetic flux wrapping around the end of the primary coil 14 when the relative position between the primary coil 14 and the secondary coil 21 is shifted, and to perform more efficient power transmission. be able to.

  Moreover, according to the non-contact power feeding device of the present embodiment, by arranging the divided coils constituting the secondary coil 21 so as to be adjacent to each other without overlapping in the vehicle width direction of the electric vehicle, the electric station Thus, when the electric vehicle is supplied with power, the divided coils can be arranged in a direction in which misalignment is likely to occur, and efficient power transmission can be realized while the divided coils are arranged in only one direction. it can.

  The embodiment described above is merely an example of application of the present invention, and the technical scope of the present invention is not intended to be limited to the contents disclosed as the above-described embodiment. . That is, the technical scope of the present invention is not limited to the specific technical matters disclosed in the above-described embodiments, but includes various modifications, changes, alternative techniques, and the like that can be easily derived from this disclosure.

DESCRIPTION OF SYMBOLS 14 Primary coil 21 Secondary coil 21a-21e Split coil 24a-24c Coil polarity inversion circuit 25 Controller 31 Position detection pattern 32 Reading sensor 41 Pulse voltage application part 42a-42c Current sensor 50 Power meter

Claims (10)

In an electromagnetic induction type non-contact power feeding device that magnetically couples a primary coil on a power feeding side and a secondary coil on a power receiving side to transmit power in a non-contact manner from the power feeding side to the power receiving side.
A plurality of split coils constituting the secondary coil;
Coil polarity switching means capable of individually switching the polarity of the plurality of divided coils;
And a control means for controlling a switching operation of the coil polarity switching means according to the polarity of the interlinkage magnetic flux interlinking with each of the plurality of divided coils. A relative position detecting means for detecting a relative position between the primary coil and the secondary coil;
The non-contact power feeding apparatus according to claim 1, wherein the control unit controls a switching operation of the coil polarity switching unit based on a detection result of the relative position detection unit. Pulse voltage applying means for applying a pulse voltage for inspection to the primary coil;
Current detecting means for detecting each induced current flowing in each of the divided coils constituting the secondary coil when the pulse voltage applying means applies a pulse voltage for inspection to the primary coil;
2. The non-contact method according to claim 1, wherein the control unit controls a switching operation of the coil polarity switching unit based on a polarity and an amplitude of a current waveform of each divided coil detected by the current detection unit. Power supply device. It further comprises power measuring means for measuring the amount of power transmitted from the power feeding side to the power receiving side,
The control means searches for a combination pattern that maximizes the amount of power measured by the power measurement means while sequentially switching combinations of the polarities of the plurality of divided coils constituting the secondary coil, and becomes the searched combination pattern. The contactless power feeding device according to claim 1, wherein the switching operation of the coil polarity switching means is controlled as described above.   When the direction in which the relative position of the secondary coil is assumed to change with respect to the primary coil is defined as the coil shear direction, the plurality of split coils constituting the secondary coil are arranged in the coil shear direction. The non-contact power feeding device according to claim 1, wherein the non-contact power feeding devices are arranged adjacent to each other without overlapping.   6. The non-contact method according to claim 5, wherein the total value of the diameters of the plurality of split coils constituting the secondary coil in the coil shear direction is larger than the diameter of the primary coil in the coil shear direction. Power supply device.   When the amount of deviation in the coil shear direction between the primary coil and the secondary coil is zero, the positions of both ends of the primary coil in the coil shear direction are a plurality of the secondary coils. The non-contact power feeding apparatus according to claim 6, wherein the split coil coincides with an end position in the coil shear direction of any one of the divided coils.   Of the plurality of divided coils constituting the secondary coil, the diameter of the divided coils positioned at both ends in the coil shear direction is equal to or smaller than the diameter of the divided coils other than both ends in the coil shear direction. The non-contact electric power feeder as described in any one of Claims 5 thru | or 7 characterized by the above-mentioned. A secondary coil that generates an induced electromotive force by magnetic coupling with a primary coil of a fixed power supply facility; a power converter that converts the induced electromotive force generated in the secondary coil into direct current; and the power In an electric vehicle comprising a battery charged by a DC output of a converter,
The secondary coil is composed of a plurality of divided coils, the coil polarity switching means capable of individually switching the polarities of the plurality of divided coils, and the polarity of the interlinkage magnetic flux interlinked with the plurality of divided coils. And a control means for controlling the operation of the coil polarity switching means in accordance with the electric vehicle.   The electric vehicle according to claim 9, wherein the plurality of divided coils constituting the secondary coil are arranged adjacent to each other without overlapping in the vehicle width direction of the electric vehicle.

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