JP2013240164A - Noncontact power supply apparatus and noncontact power supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a noncontact power supply apparatus capable of supplying power to a power supply target without precise positioning between a power supply coil and a power reception coil and supplying and ensuring the power supply from the noncontact power supply apparatus to a power supply target even when alignment between the power supply coil and the power reception coil is poor.SOLUTION: The noncontact power supply apparatus includes: plural power supply coils 23 disposed along an opposite plane 22; a power source unit 25 that selectively supplies a high-frequency voltage to the power supply coil 23; a coil selection unit 42 that selects one or plural power supply coils 23 disposed at a position opposing to the power reception coils 33 at least a part of which is disposed on the opposite plane 22 as the target coil of excitation; and a coil control section 42 that controls the power source unit 25 to supply a high-frequency voltage to the power supply coil 23 selected by the coil selection unit 42 as the target coil of excitation.

Description

  The present invention relates to a non-contact power feeding device, and a non-contact power feeding system including a non-contact power feeding device and a powered device to which power is supplied from the non-contact power feeding device.

  2. Description of the Related Art Conventionally, a non-contact power feeding system that supplies power from a power feeding coil of a non-contact power feeding device to a power receiving coil of a power fed device by using an electromagnetic induction phenomenon is known. Such a non-contact power feeding system is inconvenient because it is necessary to position the power feeding coil and the power receiving coil.

  Therefore, the following technique is known (for example, see Patent Document 1). That is, a plurality of power feeding coils and communication means capable of communicating with the power-supplied device are arranged in a tile shape on the table mat. And the power feeding coil in the position nearest to the power receiving coil of the power supplied device is detected by comparing the communication signal levels between the plurality of communication means and the power supplied device. And it supplies with electricity only to the feeding coil in the position nearest to a receiving coil.

  Thus, even if the user does not accurately position the power feeding coil and the power receiving coil, the user simply puts the power supplied device on the desktop mat, and the power feeding coil closest to the power receiving coil of the power supplied device Contact power feeding can be performed.

JP 2006-81249 A

  However, the above-described technique has a disadvantage that the power received by the power receiving coil is reduced when the position of the power feeding coil closest to the power receiving coil is shifted from the position of the power receiving coil. For example, when there is a power supply capacity of 10 W in a state where the entire power supply coil is disposed opposite to the power receiving coil, when only 50% of the area of the power supply coil faces the power receiving coil, the power supply coil and the power receiving coil are linked. The interlinkage magnetic flux is about half. As a result, the power received by the power receiving coil, that is, the power supplied from the non-contact power feeding device to the power supplied device is substantially halved.

  An object of the present invention is to supply power to a power-supplied device without accurately positioning the power feeding coil and the power receiving coil, and even when a positional deviation occurs between the power feeding coil and the power receiving coil. It is an object to provide a non-contact power supply device that can reduce the possibility that the power supplied from the contact power supply device to the power-supplied device decreases, and a non-contact power supply system including the non-contact power supply system.

  A non-contact power feeding apparatus according to the present invention is a non-contact power feeding apparatus that has a facing surface on which a power receiving coil to be fed is opposed and supplies power to the power receiving coil disposed on the facing surface by electromagnetic induction. A plurality of power supply coils arranged along the opposing surface, a power supply unit that selectively supplies a high-frequency voltage to the plurality of power supply coils, and at least a part of the plurality of power supply coils. A coil selection unit that selects one or a plurality of power supply coils arranged at positions facing the power receiving coil arranged on the facing surface as an excitation target coil, and the coil selection unit as the excitation target coil A coil control unit for supplying the high-frequency voltage to the selected power supply coil by the power source unit.

  The power feeding coil further includes a facing area detection unit that detects a facing area that is an area facing the power receiving coil disposed on the facing surface in correspondence with each power feeding coil, Preferably, the coil selection unit selects the excitation target coil based on a facing area of each of the feeding coils detected by the facing area detection unit.

  The facing area detection unit is an inductance detecting unit that detects the inductance of each feeding coil as information indicating the facing area of each feeding coil, and the coil selection unit is detected by the inductance detecting unit. It is preferable to select the excitation target coil based on the inductance of each of the feeding coils.

  The inductance detection unit is a current detection unit that detects a current flowing through each of the power supply coils according to the high-frequency voltage as information indicating an inductance of each of the power supply coils, and the coil selection unit is configured to detect the current detection. Preferably, the excitation target coil is selected based on the currents detected by the unit.

  In addition, the coil selection unit selects, as the excitation target coil, a feeding coil corresponding to a facing area that exceeds a predetermined determination value among the facing areas detected by the facing area detection unit. It is preferable.

  A non-contact power feeding system according to the present invention includes the above-described non-contact power feeding device and a power-supplied device including the power receiving coil, and the coil selection unit is configured to detect each inductance detected by the inductance detection unit. Among them, a feeding coil having an inductance less than a preset judgment value is selected as the excitation target coil, and the judgment value is a metal piece of a preset size at a position facing one feeding coil. Is set to a value indicating an inductance that is equal to or less than the inductance of the one power supply coil when the power supply coil is disposed, and the power receiving coil simultaneously faces at least two of the plurality of power supply coils when disposed on the facing surface. It is a size and the front of one of the plurality of feeding coils and the center of the receiving coil are opposed to each other. The inductance of the feeding coil adjacent to the one of the feeding coil when the power receiving coil is disposed on the facing surface, is sized to smaller than the judgment value.

  A non-contact power feeding system according to the present invention includes the above-described non-contact power feeding device and a power-supplied device including the power receiving coil, and the coil selection unit is configured to detect each current detected by the current detection unit. Among them, a feeding coil in which a current exceeding a preset judgment value is detected is selected as the excitation target coil, and the judgment value is a metal having a preset size at a position facing one of the feeding coils. When a piece is arranged, the current value is set to be larger than the current flowing through the one feeding coil in accordance with the high-frequency voltage, and when the receiving coil is arranged on the facing surface, the plurality of feeding coils are simultaneously set Of the plurality of power feeding coils and the power receiving coil on the facing surface at a position where one center of the plurality of power feeding coils and the center of the power receiving coil are opposed to each other. The feeding coil adjacent to the one of the feeding coil when it is location, is sized to flow the determination value or more current in response to the high frequency voltage.

  Moreover, the non-contact electric power feeding system which concerns on this invention contains the above-mentioned non-contact electric power feeder and the to-be-powered apparatus provided with the said receiving coil, and the said receiving coil is larger than each said electric power feeding coil.

  Moreover, the non-contact electric power feeding system which concerns on this invention contains the above-mentioned non-contact electric power feeder and the to-be-powered apparatus provided with the 1 or several said receiving coil.

  According to the non-contact power feeding device and the non-contact power feeding system configured as described above, at least a part of the non-contact power feeding system and the non-contact power feeding system is disposed at a position facing the power receiving coil without accurately positioning the power feeding coil and the power receiving coil. Alternatively, a plurality of power feeding coils, that is, a power feeding coil that can feed power to the power receiving coil is selected as the excitation target coil. Since power is supplied to the power receiving coil by the excitation target coil, power can be supplied to the power supplied device without accurately positioning the power feeding coil and the power receiving coil. Even when the power feeding coil and the power receiving coil are misaligned, power is supplied to the power receiving coil by one or a plurality of power feeding coils arranged at least at a position facing the power receiving coil. As a result, the possibility that the power supplied from the non-contact power supply apparatus to the power supplied apparatus will be reduced.

It is explanatory drawing for demonstrating an example of a structure of the non-contact electric power feeding system which concerns on one Embodiment of this invention. It is a block diagram which shows an example of an electrical configuration of the non-contact electric power feeder shown in FIG. It is explanatory drawing for demonstrating the inductance of a feeding coil when a feeding coil and a receiving coil are opposingly arranged. It is explanatory drawing for demonstrating the interaction by the positional relationship of a feeding coil and a receiving coil. It is a graph which shows an example of the relationship between the facing area of a feeding coil and a receiving coil, and the inductance of a feeding coil. It is explanatory drawing for demonstrating the relationship between a coil facing area and the coil current of a feeding coil. It is a conceptual diagram which shows an example of the magnitude | size (coil area) of a feeding coil, and the magnitude | size (coil area) of a receiving coil. It is explanatory drawing for demonstrating the relationship between a metal piece, and the magnitude | size of a feeding coil and a receiving coil.

  Embodiments according to the present invention will be described below with reference to the drawings. In addition, the structure which attached | subjected the same code | symbol in each figure shows that it is the same structure, The description is abbreviate | omitted.

  FIG. 1 is an explanatory diagram for explaining an example of a configuration of a non-contact power feeding system according to an embodiment of the present invention. A non-contact power feeding system 1 shown in FIG. 1 is configured by combining a non-contact power feeding device 2 and a power-supplied device 3. The contactless power supply device 2 and the power supplied device 3 are configured to be separated from each other.

  The non-contact power feeding device 2 includes a substantially box-shaped housing 21, and the power-supplied device 3 includes a substantially box-shaped housing 31. In FIG. 1, the upper surface of the housing 21 of the non-contact power feeding device 2 is a facing surface 22 on which the power fed device 3 is placed. The lower surface of the casing 31 of the power-supplied device 3 is a facing surface 32 for facing and contacting the facing surface 22.

  In the non-contact power feeding device 2, a plurality of power feeding coils 23 are arranged in a two-dimensional manner substantially parallel to the facing surface 22 along the facing surface 22 inside (directly below) the facing surface 22. The plurality of power supply coils 23 are closely arranged so that the distance between the power supply coils 23 is substantially zero.

  In the power-supplied device 3, a plurality of power receiving coils 33 are disposed substantially parallel to the facing surface 32 so as to be along the facing surface 32 inside (directly above) the facing surface 32. The power supplied device 3 includes a load (not shown). Then, the power received by the power receiving coil 33 is supplied to a load (not shown).

  FIG. 2 is a block diagram showing an example of the electrical configuration of the non-contact power feeding device 2 shown in FIG. The non-contact power feeding device 2 illustrated in FIG. 2 includes a plurality of coil drive blocks B and a control unit 4. The coil drive block B is provided corresponding to each of the plurality of power supply coils 23.

  The coil drive block B includes a power feeding coil 23, a current detection unit 24, and a power supply unit 25. The power supply unit 25 includes, for example, a gate driver circuit 251, FETs (Field Effect Transistors) Q1 and Q2, and a capacitor C.

  The FET Q1 is, for example, a P-channel FET, and the FET Q2 is, for example, an N-channel FET. A power supply voltage VDD supplied from a power supply circuit (not shown) is applied to the source of the FET Q1, the drain of the FET Q1 is connected to the drain of the FET Q2, and the source of the FET Q2 is connected to the circuit ground. A connection point P1 between the FETs Q1 and FET2 is connected to the circuit ground via the capacitor C, the current detection unit 24, and the power feeding coil 23.

  In response to a control signal from the control unit 4, the gate driver circuit 251 turns on and off the FET Q1 and the FET Q2 approximately alternately at a high frequency so that when one is turned on, the other is turned off. Thereby, a high-frequency voltage is generated at the connection point P1 by the FETs Q1 and Q2. The capacitor C cuts a DC component from the high-frequency voltage generated by the FETs Q1 and Q2, and supplies the remaining high-frequency component to the feeding coil 23.

  The current detection unit 24 detects the coil current I that flows through the power feeding coil 23 based on the high-frequency voltage supplied from the power supply unit 25. Then, the current detection unit 24 outputs a signal indicating the current value of the detected coil current I to the control unit 4. The current detection unit 24 is a current sensor such as a shunt resistor or a Hall element.

  The non-contact power feeding device 2 includes the same number of coil driving blocks B configured as described above as the number of power feeding coils 23.

  The control unit 4 includes, for example, a CPU (Central Processing Unit) that executes predetermined arithmetic processing, a ROM (Read Only Memory) that stores a predetermined control program, and a RAM (Random Access Memory) that temporarily stores data. And these peripheral circuits and the like. And the control part 4 functions as the coil selection part 41 and the coil control part 42 by running the control program memorize | stored in ROM, for example.

  The coil selection unit 41 selects, as an excitation target coil, a power supply coil 23 disposed at a position facing at least a part of the power reception coil 33 disposed on the facing surface 22 among the plurality of power supply coils 23. Specifically, the coil selection unit 41 selects an excitation target coil based on, for example, the inductance of each power supply coil 23.

  FIG. 3 is an explanatory diagram for explaining the inductance of the power feeding coil 23 when the power feeding coil 23 and the power receiving coil 33 are arranged to face each other. First, as shown to Fig.3 (a), the feed coil 23 and the receiving coil 33 are opposingly arranged.

  Next, a voltage is output from the power supply unit 25, and a coil current flows through the feeding coil 23 (FIG. 3B). When a coil current flows through the feeding coil 23, an interlinkage magnetic flux is generated so as to penetrate the feeding coil 23 and the receiving coil 33 (FIG. 3C).

  When the flux linkage passes through the power receiving coil 33, a coil current that rotates in the reverse direction to the power feeding coil 23 flows through the power receiving coil 33. In the power receiving coil 33, a linkage magnetic flux in the direction opposite to the magnetic flux generated in the power feeding coil 23 is generated. Then, a current flows through the power feeding coil 23 so as to prevent the interlinkage magnetic flux generated in the power receiving coil 33 (FIG. 3D).

  As described above, when the power feeding coil 23 and the power receiving coil 33 are arranged to face each other, due to the interaction by the magnetic circuit formed by the power feeding coil 23 and the power receiving coil 33, when the power feeding coil 23 is a single unit, The current flowing through the power feeding coil 23 is different from that when the power receiving coil 33 is opposed to the power receiving coil 33. In this case, the apparent inductance of the power feeding coil 23 changes between when the power feeding coil 23 is a single unit and when the power feeding coil 23 and the power receiving coil 33 are arranged to face each other.

  FIG. 4 is an explanatory diagram for explaining the interaction depending on the positional relationship between the power feeding coil 23 and the power receiving coil 33. FIG. 5 is a graph showing an example of the relationship between the facing area of the feeding coil 23 and the receiving coil 33 and the inductance of the feeding coil 23.

  FIG. 4A is an explanatory diagram illustrating an example of the case where the position of the power feeding coil 23 and the position of the power receiving coil 33 match, that is, the case where the facing area of the power feeding coil 23 and the power receiving coil 33 is maximized. is there.

  A plane that is surrounded by the outermost windings of the power feeding coil 23 and the power receiving coil 33 and that extends in a direction perpendicular to the interlinkage magnetic flux of the power feeding coil 23 and the power receiving coil 33 is the power feeding coil 23 and the power receiving coil. This is referred to as the coil surface of the coil 33. Further, the area of the power feeding coil 23 means the area of the coil surface of the power feeding coil 23, and the area of the power receiving coil 33 means the area of the coil surface of the power receiving coil 33. Further, the area of the portion where the coil surface of the feeding coil 23 and the coil surface of the power receiving coil 33 face each other is referred to as a facing area.

  As shown in FIG. 4A, when the position of the power feeding coil 23 and the position of the power receiving coil 33 coincide with each other, the facing area of the power feeding coil 23 and the power receiving coil 33 is maximized. When the facing area between the feeding coil 23 and the receiving coil 33 is maximized, the number of interlinkage magnetic fluxes linked to the feeding coil 23 and the receiving coil 33 is maximized, and the interaction between the feeding coil 23 and the receiving coil 33 is maximized. Become. As a result, the inductance of the feeding coil 23 is minimized.

  As shown in FIG. 4B, when the position of the power feeding coil 23 and the position of the power receiving coil 33 do not coincide with each other and there is a shift in the position, the facing area of the power feeding coil 23 and the power receiving coil 33 is as shown in FIG. It becomes smaller than the case shown in a). In this case, the number of interlinkage magnetic fluxes interlinking with the power feeding coil 23 and the power receiving coil 33 is reduced. As a result, the interaction between the power feeding coil 23 and the power receiving coil 33 is reduced, and as a result, the inductance of the power feeding coil 23 becomes larger than that shown in FIG.

  As shown in FIG. 4C, when the position of the power feeding coil 23 and the position of the power receiving coil 33 are completely deviated, the facing area of the power feeding coil 23 and the power receiving coil 33 is zero. In this case, the interaction between the feeding coil 23 and the receiving coil 33 does not act, and the inductance of the feeding coil 23 is maximized.

  Therefore, for example, as shown in FIG. 5, the larger the coil facing area, the smaller the inductance between the facing area of the feeding coil 23 and the receiving coil 33 and the inductance of the feeding coil 23. Note that FIG. 5 is an example, and the inductance of the feeding coil 23 and the area directly facing the coil are not necessarily in a linear proportional relationship.

  However, since the inductance of the feeding coil 23 and the coil facing area have a one-to-one correspondence as shown in FIG. 5, the inductance of the feeding coil 23 is an example of information indicating the coil facing area. .

  FIG. 6 is an explanatory diagram for explaining the relationship between the coil facing area and the coil current of the feeding coil 23. For example, as shown in FIG. 6A, when four power feeding coils 23a, 23b, 23c, and 23d are disposed, the power receiving coil 33 is disposed to face the power feeding coil 23b and the power feeding coil 23c. ing.

  In the state shown in FIG. 6A, since the facing area of the feeding coils 23a and 23d is zero, the inductance of the feeding coils 23a and 23d is a large value from the graph shown in FIG. When the inductance of the feeding coil 23 is L, the voltage of the high-frequency voltage output from the power supply unit 25 is V, and the frequency is f, the coil current I of the feeding coil 23 is expressed by the following equation (1).

I = V / (2πfL) (1)
Therefore, the coil current I increases as the inductance decreases. Since the coil current I and the inductance have a one-to-one correspondence, the coil current I detected by the current detection unit 24 is an example of information indicating the inductance of the feeding coil 23.

  At the same time, the coil current I increases as the facing area increases. Since the coil current I and the facing area have a one-to-one correspondence, the coil current I detected by the current detection unit 24 is also an example of information indicating the facing area of the feeding coil 23.

  That is, the current detection unit 24 is an example of an inductance detection unit and a facing area detection unit.

  As described above, since the coil current I is smaller as the facing area is smaller, the coil current I flowing through the feeding coils 23a and 23d having the facing area is zero, as shown in FIG. Small value. In this way, a current value slightly larger than the coil current I flowing through the power feeding coils 23a and 23d having the directly facing area is set as a determination value in advance.

  Further, the coil current I flowing through the power feeding coils 23b and 23c facing the power receiving coil 33 is larger than that of the power feeding coils 23a and 23d and larger than the determination value. Since the facing area of the feeding coil 23b is larger than the facing area of the feeding coil 23c, the coil current I flowing through the feeding coil 23b is larger than the coil current I flowing through the feeding coil 23c.

  The coil selection unit 41 selects, as an excitation target coil, the feeding coil 23 in which the coil current I detected by the current detection unit 24 is larger than the determination value. That is, the coil selection unit 41 selects the feeding coil 23 having a larger facing area than the facing area indicated by the determination value as the excitation target coil, and selects the feeding coil 23 having an inductance smaller than the inductance indicated by the determination value. Select as the excitation target coil.

  For example, in the example illustrated in FIG. 6, the coil selection unit 41 selects the power supply coils 23 b and 23 c as excitation target coils.

In this case, based on the coil current I, the coil selection unit 41 has selected the feeding coil 23 having an inductance smaller than the inductance corresponding to the determination value as the excitation target coil. At the same time, the coil selection unit 41 has selected the feeding coil 23 having a facing area larger than the facing area corresponding to the determination value as the excitation target coil. The coil control unit 42 is excited by the coil selecting unit 41. A high frequency voltage is supplied by the power supply unit 25 to the power supply coil selected as the target coil, for example, the power supply coils 23b and 23c. Accordingly, for example, in the example illustrated in FIG. 6, power is supplied from the plurality of power feeding coils 23 b and 23 c to the power receiving coil 33.

  Thereby, if the user places the power-supplied device 3 on the facing surface 22 shown in FIG. 1, the coil selection unit 41 does not accurately position the power supply coil 23 and the power reception coil 33. One or a plurality of power supply coils 23 that face each other are selected as excitation target coils. Then, a high frequency voltage is supplied to the excitation target coil, and power is supplied from the excitation target coil to the power receiving coil 33. Therefore, power can be supplied from the non-contact power supply device 2 to the power-supplied device 3 without positioning the power supply coil 23 and the power reception coil 33 accurately.

  Further, as shown in FIG. 6A, for example, even when a positional deviation occurs between the power receiving coil 33 and the power feeding coil 23 so that the power receiving coil 33 straddles the plurality of power feeding coils 23b and 23c, Since the power is supplied from the power supply coils 23b and 23c to the power receiving coil 33, even if the power supply coil 23 and the power receiving coil 33 are misaligned, the power is supplied from the non-contact power supply device 2 to the power supplied device 3. It is possible to reduce the possibility that the power is reduced.

  For example, as shown in FIG. 7, the size of the power feeding coil 23 (coil area) may be different from the size of the power receiving coil 33 (coil area).

  For example, when the power supply capacity of the power supply coil 23 is 10 W, the power reception coil 33 is made larger than the power supply coil 23, so that power (for example, 15 W) exceeding the power supply capacity (10 W) for one power supply coil 23 is received by the power reception coil. 33 can receive power.

  If the power receiving coil 33 is made larger than the power feeding coil 23, the power receiving coil 33 faces the plurality of power feeding coils 23 regardless of the position where the power receiving coil 33 is disposed oppositely. Is selected as the excitation target coil.

  As a result, the power receiving coil 33 is supplied with power from the plurality of power supply coils 23. Therefore, it is possible for the power receiving coil 33 to receive power exceeding the supply capacity of one power supply coil 23.

  Further, the power supplied device 3 may include a plurality of power receiving coils 33. When the power supplied apparatus 3 includes a plurality of power receiving coils 33, the plurality of power feeding coils 23 are always selected as excitation target coils by the coil selection unit 41. As a result, power is supplied from the plurality of power supply coils 23 to the power supplied device 3. Therefore, it is possible for the power supplied device 3 to receive power exceeding the supply capacity of one power supply coil 23.

  By the way, when a metal piece is placed at a position facing the power supply coil 23, the metal piece may be heated when the power supply coil 23 is driven. Examples of such metal pieces include coins (1-yen coin (aluminum), 5-yen coin (brass), 10-yen coin (bronze), 50-yen coin (bronze), 100-yen coin (bronze)).

  When the metal piece is placed at a position facing the feeding coil 23 and a magnetic flux passes through the metal piece, an eddy current flows through the metal piece. For this reason, an interaction occurs between the feeding coil 23 and the metal piece, and the inductance of the feeding coil 23 and the coil current I change.

  Therefore, a value slightly larger than the coil current I and slightly smaller than the inductance of the power supply coil 23 when such a metal piece is placed at a position facing the power supply coil 23 is set as a determination value. It is preferable.

  Thereby, when a metal piece is mounted in the position facing the electric power feeding coil 23, the electric power feeding coil 23 is made not to become an excitation object coil.

  FIG. 8 is an explanatory diagram for explaining the relationship between the metal piece and the sizes of the feeding coil 23 and the receiving coil 33. As shown in FIG. 8A, a current value larger than the coil current I when the metal piece A is placed at a position facing the feeding coil 23a is set as a determination value, that is, a position facing the feeding coil 23a. A value indicating an inductance smaller than the inductance of the feeding coil 23a when the metal piece A is placed on is set as a determination value (FIG. 8B).

  However, when such a value is set as the determination value, the following inconvenience may occur. That is, when the power receiving coil 33 is made larger than the power feeding coil 23 so as to face the plurality of power feeding coils 23 in order to receive the power exceeding the power supply capacity of one power feeding coil 23 as the required power, the facing area ( The feeding coil 23 whose coil current I) does not exceed the determination value (the feeding coil 23 whose inductance does not reach the determination value) is not selected as the excitation target coil. Since the high-frequency current is not supplied to the feeding coil 23 that is not selected as the excitation target coil, the power received by the power receiving coil 33 may not satisfy the required power.

  In particular, when the center of one power supply coil 23c and the center of the power reception coil 33 are arranged to face each other, the facing area (coil current I) of the other power supply coils 23b and 23d adjacent to the power supply coil 23c. If the value does not exceed the determination value, only one power feeding coil 23c is selected as the excitation target coil, so that the power received by the power receiving coil 33 is most likely to be less than the required power. (Although not shown in FIG. 8A, not only the power supply coils 23b and 23d but also a total of eight power supply coils 23 are adjacent to the power supply coil 23c in the front, rear, left, and right directions. ing.)

  Therefore, as shown in FIG. 8, the size of the power receiving coil 33 (for example, the diameter of the outermost winding) is set to a size that simultaneously faces the plurality of power feeding coils 23 when arranged on the facing surface 22. As shown in FIG. 8 (a), when the power receiving coil 33 is disposed at a position where the center of the power feeding coil 23c and the center of the power receiving coil 33 face each other, the power feeding coils 23b and 23d adjacent to the power feeding coil 23c are directly opposed. It is preferable that the area (coil current I) is larger than the directly facing area (coil current) indicated by the determination value.

  Alternatively, the size of the power receiving coil 33 is set so as to simultaneously face the plurality of power feeding coils 23 when arranged on the facing surface 22, and as shown in FIG. 8A, the center of the power feeding coil 23c and the power receiving coil When the power receiving coil 33 is arranged at a position opposite to the center of the power supply 33, the inductances of the power feeding coils 23b and 23d adjacent to the power feeding coil 23c may be made smaller than the inductance indicated by the determination value. preferable.

  By setting the power receiving coil 33 to such a size, even when the power receiving coil 33 is disposed so that the center of the power feeding coil 23c and the center of the power receiving coil 33 coincide with each other, the power receiving coil 33 is adjacent to the power feeding coil 23c. The facing area (coil current I) of the other power supply coils 23b and 23d exceeds the determination value (inductance is lower than the determination value), and the other power supply coils 23b and 23d adjacent to the power supply coil 23c are the excitation target coils. Can be selected.

  As a result, even when the metal piece A is placed on the facing surface 22, it is possible to reduce the possibility that the power received by the power receiving coil 33 does not satisfy the required power while reducing the possibility of heating the metal piece A. .

  Although the current detection unit 24 is shown as an example of the facing area detection unit, the current detection unit 24 is not necessarily limited to an example in which the current detection unit 24 is used as the facing area detection unit. For example, the facing area detection unit may be configured using an optical sensor that detects the power supplied device 3. Specifically, whether or not a plurality of photosensors are arranged in a plane along the facing surface 22 and the power-supplied device 3 placed on the facing surface 22 is placed by the plurality of photosensors. May be detected. The facing area detection unit detects the placement position of the power-supplied device 3 from the detection information of the power-supplied device 3 obtained from a plurality of optical sensors, and based on the position information, The feeding coil 23 at a position facing the mounting position may be specified, and the facing area between the feeding coil 23 and the receiving coil 33 may be calculated.

  Moreover, although the current detection unit 24 is shown as an example of the inductance detection unit, the current detection unit 24 is not necessarily limited to the example using the inductance detection unit. Instead of using the current detection unit 24, the inductance detection unit may be configured by a known inductance measurement unit.

  That is, the non-contact power feeding system according to the present invention has a facing surface on which a power receiving coil to be fed is opposed, and supplies power to the power receiving coil disposed on the facing surface by an electromagnetic induction phenomenon. A plurality of power supply coils arranged along the opposing surface, a power supply unit that selectively supplies a high-frequency voltage to the plurality of power supply coils, and at least of the plurality of power supply coils A coil selection unit that selects one or a plurality of power supply coils disposed at positions facing a part of the power receiving coil that is partially disposed on the facing surface as a coil to be excited, and the excitation target by the coil selection unit A coil control unit for supplying the high-frequency voltage to the power supply coil selected as the coil by the power supply unit.

  According to this configuration, the plurality of power feeding coils are arranged along the facing surface where the power receiving coils to be fed are opposed to each other. Then, one or a plurality of power supply coils, at least a part of which are disposed at a position facing the power reception coil, among the plurality of power supply coils are selected as excitation target coils. Then, a high frequency voltage is supplied from the power supply unit to the power supply coil selected as the excitation target coil. Accordingly, even if the feeding coil and the receiving coil are not accurately positioned, at least a portion of the feeding coil disposed at a position facing the receiving coil, that is, a feeding coil capable of feeding the receiving coil is provided. Selected as a coil to be excited. Since power is supplied to the power receiving coil by the excitation target coil, power can be supplied to the power supplied device without accurately positioning the power feeding coil and the power receiving coil.

  Even when the power feeding coil and the power receiving coil are misaligned, power is supplied to the power receiving coil by one or a plurality of power feeding coils arranged at least at a position facing the power receiving coil. As a result, the possibility that the power supplied from the non-contact power supply apparatus to the power supplied apparatus will be reduced.

  The power feeding coil further includes a facing area detection unit that detects a facing area that is an area facing the power receiving coil disposed on the facing surface in correspondence with each power feeding coil, Preferably, the coil selection unit selects the excitation target coil based on a facing area of each of the feeding coils detected by the facing area detection unit.

  According to this configuration, when there is one or a plurality of power feeding coils disposed at a position at least partially facing the power receiving coil, the area of at least a portion facing is set as the facing area by the facing area detection unit. Detected as Therefore, the coil selection unit can select the excitation target coil based on the facing area of each feeding coil detected by the facing area detection unit.

  The facing area detection unit is an inductance detecting unit that detects the inductance of each feeding coil as information indicating the facing area of each feeding coil, and the coil selection unit is detected by the inductance detecting unit. It is preferable to select the excitation target coil based on the inductance of each of the feeding coils.

  When the power feeding coil and the power receiving coil face each other, a magnetic circuit is configured by the power feeding coil and the power receiving coil, and the inductance of the power feeding coil changes due to magnetic interaction. Therefore, an inductance detection unit that detects the inductance of each power supply coil as information indicating the frontal area of each power supply coil can be used as the frontal area detection unit. In this case, since the inductance of each power supply coil represents the frontal area of each power supply coil, the coil selection unit can select the excitation target coil based on the inductance of each power supply coil.

  The inductance detection unit is a current detection unit that detects a current flowing through each of the power supply coils according to the high-frequency voltage as information indicating an inductance of each of the power supply coils, and the coil selection unit is configured to detect the current detection. Preferably, the excitation target coil is selected based on the currents detected by the unit.

  The current flowing through each power supply coil in accordance with the high-frequency voltage changes according to the inductance of each power supply coil. Therefore, a current detection unit that detects the current flowing through each power supply coil as information indicating the inductance of each power supply coil can be used as the inductance detection unit. In this case, since the current flowing through each feeding coil represents the inductance of each feeding coil, the coil selection unit selects the excitation target coil based on the current flowing through each feeding coil detected by the current detection unit. Can do.

  In addition, the coil selection unit selects, as the excitation target coil, a feeding coil corresponding to a facing area that exceeds a predetermined determination value among the facing areas detected by the facing area detection unit. It is preferable.

  According to this configuration, the certainty that one or a plurality of power feeding coils, at least a part of which is disposed at a position facing the power receiving coil, can be selected as the excitation target coil is improved.

  A non-contact power feeding system according to the present invention includes the above-described non-contact power feeding device and a power-supplied device including the power receiving coil, and the coil selection unit is configured to detect each inductance detected by the inductance detection unit. Among them, a feeding coil having an inductance less than a preset judgment value is selected as the excitation target coil, and the judgment value is a metal piece of a preset size at a position facing one feeding coil. Is set to a value indicating an inductance that is equal to or less than the inductance of the one power supply coil when the power supply coil is disposed, and the power receiving coil simultaneously faces at least two of the plurality of power supply coils when disposed on the facing surface. It is a size and the front of one of the plurality of feeding coils and the center of the receiving coil are opposed to each other. The inductance of the feeding coil adjacent to the one of the feeding coil when the power receiving coil is disposed on the facing surface, is sized to smaller than the judgment value.

  According to this configuration, it is possible to reduce the possibility that the power received by the power receiving coil is reduced while reducing the possibility of heating the metal piece even when the metal piece is opposed to the opposing surface.

  A non-contact power feeding system according to the present invention includes the above-described non-contact power feeding device and a power-supplied device including the power receiving coil, and the coil selection unit is configured to detect each current detected by the current detection unit. Among them, a feeding coil in which a current exceeding a preset judgment value is detected is selected as the excitation target coil, and the judgment value is a metal having a preset size at a position facing one of the feeding coils. When a piece is arranged, the current value is set to be larger than the current flowing through the one feeding coil in accordance with the high-frequency voltage, and when the receiving coil is arranged on the facing surface, the plurality of feeding coils are simultaneously set Of the plurality of power feeding coils and the power receiving coil on the facing surface at a position where one center of the plurality of power feeding coils and the center of the power receiving coil are opposed to each other. The feeding coil adjacent to the one of the feeding coil when it is location, is sized to flow the determination value or more current in response to the high frequency voltage.

  According to this configuration, it is possible to reduce the possibility that the power received by the power receiving coil is reduced while reducing the possibility of heating the metal piece even when the metal piece is opposed to the opposing surface.

  Moreover, the non-contact electric power feeding system which concerns on this invention contains the above-mentioned non-contact electric power feeder and the to-be-powered apparatus provided with the said receiving coil, and the said receiving coil is larger than each said electric power feeding coil.

  According to this configuration, power can be received from the plurality of power feeding coils by the power receiving coil, so that power exceeding the supply capability of one power feeding coil can be received by the power receiving coil.

  Moreover, the non-contact electric power feeding system which concerns on this invention contains the above-mentioned non-contact electric power feeder and the to-be-powered apparatus provided with the 1 or several said receiving coil.

  According to this configuration, power can be supplied to the power-supplied device without accurately positioning the power feeding coil and the power receiving coil, and even if the power feeding coil and the power receiving coil are misaligned, The possibility that the power supplied from the contact power supply device to the power supplied device may be reduced. Further, when the power supplied device includes a plurality of power receiving coils, the power supplied device can receive power exceeding the supply capability of one power feeding coil by the power receiving coils.

DESCRIPTION OF SYMBOLS 1 Non-contact electric power feeding system 2 Non-contact electric power feeder 3 Power-supplied apparatus 4 Control part 21,31 Housing | casing 22,32 Opposite surface 23,23a, 23b, 23c, 23d Feeding coil 24 Current detection part 25 Power supply part 33 Power receiving coil 41 Coil Selection unit 42 Coil control unit 251 Gate driver circuit A Metal piece B Coil drive block C Capacitors Q1, Q2 FET
I Coil current

Claims (9)

A non-contact power feeding device that has a facing surface on which a power receiving coil to be fed is opposed, and supplies power to the power receiving coil disposed on the facing surface by electromagnetic induction,
A plurality of feeding coils arranged along the opposing surface;
A power supply unit that selectively supplies a high-frequency voltage to the plurality of feeding coils;
A coil selection unit that selects one or a plurality of power supply coils arranged at positions facing at least a part of the power reception coil disposed on the facing surface among the plurality of power supply coils as excitation target coils; ,
A non-contact power feeding apparatus comprising: a coil control unit configured to supply the high frequency voltage to the power feeding coil selected as the excitation target coil by the coil selection unit by the power source unit. The power supply coil further includes a facing area detection unit that detects a facing area that is an area facing the power receiving coil disposed on the facing surface in correspondence with each power feeding coil,
The coil selector is
The non-contact power feeding apparatus according to claim 1, wherein the excitation target coil is selected based on a facing area of each of the feeding coils detected by the facing area detection unit. The facing area detection unit includes:
An inductance detection unit that detects the inductance of each of the power supply coils as information indicating a facing area of each of the power supply coils;
The coil selector is
The non-contact power feeding apparatus according to claim 2, wherein the excitation target coil is selected based on an inductance of each of the power feeding coils detected by the inductance detection unit. The inductance detector is
A current detection unit that detects a current flowing through each of the power supply coils according to the high-frequency voltage as information indicating an inductance of each of the power supply coils;
The coil selector is
The non-contact electric power feeder of Claim 3 which selects the said excitation object coil based on each said electric current detected by the said electric current detection part. The coil selector is
The feeding coil corresponding to the facing area exceeding a predetermined determination value among the facing areas detected by the facing area detection unit is selected as the excitation target coil. The contactless power supply device according to item 1. The non-contact power feeding device according to claim 3 or 4,
A power supplied device including the power receiving coil,
The coil selector is
Of each inductance detected by the inductance detection unit, a feeding coil having an inductance that does not satisfy a predetermined determination value is selected as the excitation target coil,
The judgment value is
It is set to a value indicating an inductance that is equal to or less than the inductance of the one feeding coil when a metal piece of a preset size is disposed at a position facing the one feeding coil,
The power receiving coil is
When arranged on the facing surface, the size is such that at least two of the plurality of feeding coils are simultaneously opposed to each other, and the center of the plurality of feeding coils and the center of the receiving coil are opposed to each other. The non-contact electric power feeding system which is a magnitude | size which makes the inductance of the electric power feeding coil adjacent to the said one electric power feeding coil smaller than the said determination value when the said receiving coil is arrange | positioned at the said opposing surface. A non-contact power feeding device according to claim 4,
A power supplied device including the power receiving coil,
The coil selector is
Of each of the currents detected by the current detection unit, select a feeding coil in which a current exceeding a preset determination value is detected as the excitation target coil,
The judgment value is
When a metal piece of a preset size is disposed at a position facing one of the feeding coils, the current value is set to be larger than the current flowing through the one feeding coil according to the high-frequency voltage,
The power receiving coil is
When arranged on the facing surface, the size is such that at least two of the plurality of feeding coils are simultaneously opposed to each other, and the center of the plurality of feeding coils and the center of the receiving coil are opposed to each other. A non-contact power feeding system having a size that allows a current equal to or greater than the determination value to flow in a power feeding coil adjacent to the one power feeding coil when the power receiving coil is disposed on the facing surface. The contactless power supply device according to any one of claims 1 to 5,
A power supplied device including the power receiving coil,
The said receiving coil is a non-contact electric power feeding system larger than each said electric power feeding coil. The contactless power supply device according to any one of claims 1 to 5,
A non-contact power supply system including a power supplied device including one or a plurality of the power receiving coils.

Images