TW201429110A - Power feeding device and wireless power feeding system - Google Patents

Abstract

A power feeding device having N power feeding coils from a first system to an Nth system (N is an integer no less than two) to wirelessly feed power to a power receiving device having N power receiving coils from a first system to an Nth system, the power feeding device performing the wireless power feeding by allowing AC current to flow in each of the N power feeding coils and generating electromagnetic induction in each system due to the power feeding coils and the power receiving coils. The N power feeding coils are each arranged substantially on the same plane, and the directions of the AC currents flowing in the adjoining power feeding coils are continuously flowing in the reverse of each other.

Description

Power feeding device and wireless power feeding system

The present invention relates to a power feeding device for wireless power feeding and a wireless power feeding system therewith.

In recent years, so-called wireless power feeding technology that performs power transmission by electromagnetic coupling between coils without contact has been popularized. Starting from "AQUOS PHONE (registered trademark) SH-13C", which was released in August 2011, the technology related to "wireless charging (registered trademark)" promoted in the field of mobile phones is the representative of the wireless power supply technology.

Fig. 8 schematically shows a combination of a charger 811 and an electric device 812 as an example of a device to which a wireless power feeding system is applied. 8(a) is a perspective view showing a state in which the charger 811 and the electric device 812 are separated, and FIG. 8(b) is a cross-sectional view showing a side view of the state in which the electric device 812 is placed on the charger 811. Further, the charger 811 includes a power feeding device (wireless power feeding device), and the electric device 812 includes a power receiving device (wireless power receiving device).

Furthermore, FIG. 8(b) more specifically shows the state in which the charger 811 is placed on the table, and the electric device 812 is placed on the charger 811. When the electrical device 812 is charged, as shown in the figure, the electrical device 812 can be placed on the charger 811. By placing in this manner, the electric device 812 can be charged by wirelessly transmitting power of up to 5 W from the power feeding device to the power receiving device without performing cable connection or the like.

Most of the currently available wireless power-receiving devices are designed according to standards set by the industry group, WPC (Wireless Power Consortium) (known as "Qi", hereinafter referred to as "Qi standard"). Details of the Qi standard have been disclosed in the written standard Quasi (Non-Patent Document 1), the outline of the internal circuit configuration of the power supply device and the power receiving device has also been defined.

Fig. 6 shows an example of the internal circuit configuration of the wireless power feeding system. A portion of the power feeding device 611 directly refers to FIGS. 3-8, and a portion of the power receiving device 612 directly refers to FIG. 4-3.

In the power feeding device 611, the power of the DC power source 601 is converted into AC power by the inverter circuit 614, and supplied to the power feeding coil L611. Thereby, electromagnetic induction is generated in the power feeding coil L611 and the power receiving coil L612, and the AC power is wirelessly transmitted from the power feeding device 611 to the power receiving device 612.

Further, in order to improve the performance, resonance capacitors (C611, C612) are inserted before and after the coils. In the power receiving device 612, the AC power received by the power receiving coil L612 is restored to DC power by the rectifier circuit 617, and is output from the output terminal 602. The output power is used by the device side including the power receiving device 612.

Further, a control circuit 613 for controlling the inverter circuit 614 is provided in the power feeding device 611. The control circuit 613 controls on/off switching of each of the switching elements (S1 to S4) in the inverter circuit 614 in a manner of appropriately performing power conversion.

Further, communication between the power feeding device 611 and the power receiving device 612 is performed in accordance with the control information of the Qi standard. Therefore, in the power feeding device 611, the signal receiving circuit 615 is connected to the power feeding coil L611 via the capacitor C613. Further, in the power receiving device 612, the load modulation circuit 616 is connected to the power receiving coil L612. Thereby, communication can be performed between the power feeding device 611 and the power receiving device 612.

Moreover, FIG. 7 shows an example of a structure of the coil L600 serving as the power feeding coil L611 or the power receiving coil L612 and its periphery. The coil L600 shown in Fig. 7 is an A1 coil disclosed in Section 3.2.1.1.1 of Non-Patent Document 1, and is the most common coil at present. As shown in FIG. 7, the coil L600 is a circular coil formed by winding a copper wire, and is attached to the surface of the magnetic plate 704. Further, both ends of the coil L600 are connected to the wiring patterns (P711, P712) provided on the circuit board 703 by soldering.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2010-187495

[Non-patent literature]

[Non-Patent Document 1]

System Description Wireless Power Transfer

Volume I: Low Power

Part 1: Interface Definition

Version 1.0.3 September 2011

The above-mentioned prior wireless power feeding system does not cause a particular problem as long as it outputs a small power of about 5 W as envisioned by the original Qi standard. However, with the popularization of the Qi standard, the tendency of high output is enhanced, and relatively large power needs to be output, the previous wireless power supply system mainly causes two problems.

First, in order to achieve a specification that can withstand large power, it is necessary to make the components of the wireless power feeding system an expensive part with high power resistance. Therefore, the following problem is cited as the first problem, which means that the manufacturing cost of the wireless power feeding system is significantly increased.

Moreover, the excess magnetic field radiation that leaks toward the periphery of the wireless power feeding system is increased due to the output of large power. Therefore, the following question is included as the second problem, which means that the surrounding equipment or human body is easily affected by the radiation caused by the excess magnetic field.

Furthermore, if the AC magnetic field of a large electric power is received, there is a risk that malfunction may occur in the surrounding electronic equipment or in a wireless device such as a radio. Further, it is known that the human body is stimulated by a strong magnetic field, and there is a possibility that it may adversely affect health. Therefore, the International Commission on Non-Ionizing Radiation Protection (ICNIRP, International Commission on Non-Ionizing) Radiation Protection has established guidelines for the strength of magnetic fields that do not adversely affect health and must be adhered to.

Of course, the greater the output power of the wireless power feeding device, the more serious the problem of excess magnetic field radiation as described above. The charging station for mobile phones that has been circulated in the market is a small power device of about 5W. However, in the future, if general household appliances such as personal computers, TVs, refrigerators, dust collectors, and washing machines are also adopting wireless power supply technology, 10W~100W High output is inevitable, and the suppression of excess magnetic field radiation becomes an important issue.

The present invention has been made in view of the above problems, and an object thereof is to provide a power feeding device and a wireless power feeding system having the same, which can easily realize an inexpensive and high-output wireless power feeding system and can suppress excessive magnetic field radiation.

The power feeding device of the present invention includes N power feeding coils of the first series to the Nth series (N is an integer of 2 or more), and wirelessly supplies power to the power receiving devices including the N series power receiving coils of the first series to the Nth series, and a configuration is adopted in which an alternating current is caused to flow through each of the N power feeding coils, and electromagnetic induction by the power feeding coil and the power receiving coil is generated in each series to perform the wireless power feeding; the N power feedings. Each of the coils is disposed on substantially the same plane, and the direction of the alternating current in the adjacent ones of the power feeding coils is always opposite to each other.

According to this configuration, it is easy to realize an inexpensive and high-output wireless power feeding system, and it is possible to suppress unnecessary magnetic field radiation.

Further, the wireless power feeding system of the present invention includes: the power transmitting device configured as described above, and a power receiving device including N power receiving coils of the first to Nth series, and in a state where the power receiving device and the power feeding device are positioned The radio power is supplied to each other, and each of the N power receiving coils is disposed on substantially the same plane so as to face the same series of the power feeding coils in the positioned state.

Further, as the above configuration, more specifically, it may be configured as follows: The device includes N inverter circuits of the first series to the Nth series, and a control circuit for controlling the operation of each of the N inverter circuits, and the DC power is used by each of the N inverter circuits Converting to AC power, and transmitting the AC power to the same series of the power feeding coils; the power receiving device includes N rectifier circuits of the first series to the Nth series, and an output terminal, and the N rectifier circuits are Each of them converts AC power received from the above-described power receiving coil of the same series into DC power, and the DC power is sent to the output terminal.

Further, the wireless power feeding system having the above configuration may be configured such that the number of the load modulation circuits and the number of the signal receiving circuits are one, and the wireless power feeding system having the above configuration is configured by a load. A load modulation circuit that transmits a wireless signal by modulation is provided in the power receiving device, and a signal receiving circuit that receives the wireless signal is provided in the power feeding device, and communicates between the load modulation circuit and the signal receiving circuit.

Further, in the wireless power feeding system in which the above-described communication monitoring is performed in the standby state in which the predetermined power feeding start condition is satisfied, the signal receiving circuit may be connected to the Kth series. (K is a power supply coil of any one of 1 to N); the load modulation circuit is connected to the power receiving coil of the Kth series; and the control circuit causes the inverter of the Kth series during the standby state The circuit is driven, and on the other hand, the remaining N-1 inverter circuits are stopped, and when the above-described power-on start condition is satisfied, all of the N inverter circuits are driven.

According to the power feeding device of the present invention, it is easy to realize an inexpensive and high-output wireless power feeding system, and it is possible to suppress unnecessary magnetic field radiation. Further, according to the wireless power feeding system of the present invention, the advantages of the power feeding device of the present invention can be enjoyed.

1‧‧‧Wireless power system

101‧‧‧DC Power Supply Department

102, 602‧‧‧ output terminals

111,611‧‧‧Power supply

112, 612‧‧‧Power-receiving devices

113, 613‧‧‧ control circuit

114 _a ~114 _c , 614‧‧‧ inverter circuit

115, 615‧‧‧ signal receiving circuit

116, 616‧‧‧ load modulation circuit

123‧‧‧Switch circuit

127 _a ~127 _c , 617‧‧‧Rectifier circuit

303, 503, 703‧‧‧ circuit board

304, 504, 704‧‧‧ magnetic plate

601‧‧‧DC power supply

811‧‧‧Charger

812‧‧‧Electrical equipment

A, B‧‧ points

C1 _a ~C1 _c , C2 _a ~C2 _c , C3 , C613‧‧‧ capacitor

C611, C612‧‧‧ resonant capacitor

CS, CS1, CS2‧‧‧ close parts

G1~G4‧‧‧ control signal

Ia, Ib‧‧‧ current

L1 _a ~ L1 _c , L611‧‧‧ power supply coil

L2 _a ~ L2 _c , L612‧‧‧ power receiving coil

L600‧‧‧ coil

P311, P312, P321, P322, P511, P512, P521, P522, P531, P532, P711, P712‧‧‧ wiring patterns

S1 _a ~S4 _a , S1 _b ~S4 _b , S1 _c ~S4 _c , S1~S4‧‧‧ switching elements

Sr‧‧‧ wireless signal

Fig. 1 is a configuration diagram of a wireless power feeding system according to a first embodiment.

Fig. 2 is an explanatory view showing a structure in the vicinity of the power feeding coil of the first embodiment.

Figure 3 is an illustration of the principle of suppressing unwanted electromagnetic field radiation.

Fig. 4 is a view showing the configuration of a wireless power feeding system according to a second embodiment;

Fig. 5 is an explanatory view showing a structure in the vicinity of a power feeding coil of the second embodiment.

Fig. 6 is a configuration diagram relating to the wireless power feeding system of the prior art.

Fig. 7 is an explanatory view relating to the construction of the coil of the prior art.

8(a) and 8(b) are explanatory diagrams related to a device to which a wireless power feeding system is applied.

Hereinafter, embodiments of the present invention will be described by taking the first embodiment and the second embodiment as examples.

1. First embodiment [The overall composition of the wireless power supply system]

First, the first embodiment will be described. Fig. 1 is a configuration diagram of a wireless power feeding system 1 according to the first embodiment. As shown in FIG. 1, the wireless power feeding system 1 has a power feeding device 111 (wireless power feeding device) and a power receiving device 112 (wireless power receiving device). The wireless power feeding system 1 is constructed in a manner suitable for the Qi standard.

Feeding device 111 includes a DC power supply unit 101, a control circuit 113, each of the inverter circuit (114 _a, 114 _b), the signal receiving circuit 115, the capacitors _{(C1 a, C1 b, C3} ), and each to a coil (L1 _a , L1 _b ). Power receiving apparatus 112 includes an output terminal 102, a load modulation circuit 116, each of the rectifier circuit (127 _a, 127 _b), each receiving coil (L2 _a, L2 _b), and each capacitor (C2 _a, C2 _b).

Moreover, as shown in FIG. 1, the wireless power feeding system 1 has the first series and the second series of power transmission mechanisms, and is a mechanism for wirelessly transmitting power from the power feeding device 111 to the power receiving device 112. In the following description, the transmission unit of the first series is simply referred to as "the first series", and the transmission unit of the second series is sometimes referred to as the "second series".

The first series comprises a control circuit 113, the inverter circuit 114 _a, a signal receiving circuit 115, a load modulation circuit 116, the capacitors _{(C1 a, C2 a, C3} ), to the coil L1 _a, receiving coil L2 _a, And a rectifier circuit 127 _a . The second series circuit includes an inverter 114 _b, each capacitor (C1 _b, C2 _b), a coil L1 _b, receiving coil L2 _b, and the rectifier circuit 127 _b.

In addition, for the elements with the "a" or "b" subscript in the quotation, the elements that are basically equal are set in the first series and the second series, and the "a" subscript indicates the elements of the first series, " The b" subscript indicates the elements of the second series. As is apparent from Fig. 1, the wireless power feeding system 1 is configured such that a power transmission mechanism of the first series and a power transmission mechanism of the second series are provided in parallel between the DC power supply unit 101 and the output terminal 102.

The power feeding device 111 and the power receiving device 112 are structurally separated from each other, but the wireless power feeding system 1 is wirelessly capable of positioning the devices appropriately (in such a manner that the series of power feeding coils and the power receiving coil are close to each other and facing each other). The state of power supply (composed in Figure 1). When the wireless power feeding system 1 is wirelessly powered, the positioning is performed in the above-described manner, and the state after the positioning is maintained to perform wireless power feeding.

The DC power supply unit 101 is configured by, for example, a battery or an AC (Alternating Current) adapter connected to a commercial power source, and functions as a DC power supply. DC power supply unit 101 supplying DC power to each of the inverter circuit (114 _a, 114 _b).

The inverter circuit 114 _a system having a plurality of inverter circuit switching elements (S1 _a ~ S4 _a) the full-bridge configuration, the inverter circuit 114 _b system having a plurality of switches (S1 _b ~ S4 _b) wholly The inverter circuit of the bridge structure.

Further, in the inverter circuit 114 _a, the end of the switching element S1 _a and S3 _a portion of the DC power supply 101 is connected, and the switching element S2 _a one S4 _a ground. The other end of the switching element S1 _a switching element is directly connected to the other end S2 _a, and is connected to one end of a coil L1 _a sum via a capacitor C1 _a. The other end of the switching element S3 _a connection to the other ends of the switching element S4 _a and to the coil L1 _a.

Further, in the inverter circuit 114 _b, and the switching element S1 _b is connected to the one end S3 _b of the DC power supply unit 101, the switching element S2 _b and S4 _b grounded one. The other end of the switching element S1 _b is directly connected to the other end of the switching element S2 _b and is connected to one end of the power feeding coil L1 _b via a capacitor C1 _b . The other end of the switching element S3 _b is connected to the other end of the switching element S4 _b and the other end to the coil L1 _b.

Each inverter circuit (114 _a, 114 _b) having the above configuration, each of the switching elements is turned on by the on / off switch, to convert AC power from the DC power supply 101 of the DC power supply unit. The inverter circuit 114 _a generated by said converter to the AC power to the feeding coil L1 _a, 114 _b to the inverter circuit is generated by said converter to the AC power to the feeding coil L1 _b.

Conducting each of the switching elements of the inverter circuit (114 _a, 114 _b) of the on / off switching by the control system 113 the control circuit. That is, the control circuit 113 to the respective inverter circuits (114 _a, 114 _b) is suitably operated in such manner, and generating an output for each of the switching elements of the control signals (G1 ~ G4 ON / OFF switching of ). For example, when each switching element is a FET (Field Effect Transistor), the control circuit 113 generates a pulse signal in which the H level and the L level alternately appear as the respective control signals (G1 to G4) and outputs them to the respective signals. The gate of the FET.

Further, the control circuit 113 via the same wiring connected to the switching element S1 _a and S1 _b, the wirings via the switching element to the output control signals such as G1. Further, the control circuit 113 via the same wiring connected to the switching element S2 _a and S2 _b, G2 outputs a control signal via the switching element to the wiring and the like. Further, the control circuit 113 via the same wiring connected to the switching element S3 _a and S3 _b, G3 via the switching element to the output control signal of the wirings and the like. Further, the control circuit 113 via the same wiring connected to the switching element S4 _a and S4 _b, G4 via a switching element which outputs a control signal to the wirings and the like.

According to the above, the pair of switching elements S1 _a and S1 _b , the pair of switching elements S2 _a and S2 _{b ,} the pair of switching elements S3 _a and S3 _b , and the pair of switching elements S4 _a and S4 _b are respectively synchronized. Take action. Thus, each of the inverter circuit (114 _a, 114 _b) output synchronously with each other with the phase of the AC power.

The signal receiving circuit 115 is connected to the power feeding coil L1 _a via the capacitor C3, and receives the wireless signal Sr from the power receiving device 112 side (load modulation circuit 116). In addition, although one part of the transmission power in the first series is used as the driving power of the signal receiving circuit 115, it may be in other forms.

One end of the coil L2 _a via capacitor C2 _a is connected to one input terminal of the rectifier circuit 127 _a subject. And, receiving the other end of the coil L2 _a is connected to the other input terminal of the rectifier circuit 127 _a. One end of the power receiving coil L2 _b is connected to one input terminal of the rectifier circuit 127 _b via a capacitor C2 _b . Further, the other end of the power receiving coil L2 _b is connected to the other input terminal of the rectifier circuit 127 _b . Further, each of the capacitors (C1 _a , C1 _b , C2 _a , and C2 _b ) is inserted into a resonance capacitor before and after the power feeding and receiving coils in order to improve performance.

A load modulation circuit 116 via the capacitor C2 _a is connected to the receiving coil L2 _a, a wireless signal transmitted by a change of load modulation generated Sr. Further, one of the transmission powers in the first series is used as the driving power of the load modulation circuit 116, but may be other forms.

As described above, the wireless signal Sr is received by the signal receiving circuit 115 on the power transmitting device 111 side. Thereby, communication related to wireless power feeding can be performed between the power transmitting device 111 and the power receiving device 112. Further, the configuration of the signal receiving circuit 115 or the load modulation circuit 116 and the specific form of the related communication are well known, and thus detailed description thereof is omitted here.

The rectifier circuit 127 _a converts the AC power transmitted from the power receiving coil L2 _a into DC power, and sends the DC power to the output terminal 102. Further, the rectifier circuit 127 _b from the receiving coil L2 _b transport from the AC power into DC power and DC power fed to the output terminal 102.

Output terminal 102 is connected to a secondary battery having a receiving (not shown) in the electrical equipment of the electrical apparatus 112, from each of the rectification circuit (127 _a, 127 _b) Synthesis of electric power to be accepted and output. Whereby, out of the DC power supplied from each of the rectification circuit (127 _a, 127 _b) via a single terminal 102 to the output of the secondary battery, and is used as a drive power to the electrical equipment and the like. In the present embodiment, the output power from the output terminal 102 is supplied to the secondary battery, but the supply destination of the output power or the like is not limited to this form.

FIG. 2 exemplifies a structure (mounting form) in the vicinity of each of the power feeding coils (L1 _a , L1 _b ) in the power feeding device 111. Each of the power feeding coils (L1 _a , L1 _b ) is a circular coil formed by winding a copper wire in the same direction, and is attached to the surface of the magnetic body plate 304, thereby being disposed substantially adjacent to each other in a substantially adjacent manner. on flat surface. Further, both ends of the respective power feeding coils (L1 _a , L1 _b ) are soldered to wiring patterns (P311, P312, P321, P322) provided on the circuit board 303.

P311 is connected to the wiring pattern between the switching element S3 _a and S4 _a, the wiring pattern P312 connected to one end of the capacitor C1 _a. P321 wiring pattern connected to one end of the capacitor C1 _b, the wiring pattern P322 is connected between the switching element S3 _b and S4 _b.

Further, the three wiring patterns (P311, P312, and P321) are disposed on the front surface side of the circuit board 303, and the remaining wiring patterns P322 are disposed on the back side of the circuit board 303 so as to be three-dimensionally intersected with the wiring pattern P321. The reason for such a three-dimensional intersection is that the alternating currents flowing through the respective power feeding coils (L1 _a , L1 _b ) are reversed each other (the meaning of the reverse direction is clarified by the description below).

Further, in the state in which the power receiving device 112 and the power feeding device 111 are positioned as described above, the respective power receiving coils (L2 _a and L2 _b ) are disposed on substantially the same plane so as to face the same series of power feeding coils.

To the power receiving device 112 and the positioning power supply device 111, when the wireless power feeding system 1 to the power control circuit 113 outputs control signals (G1 ~ G4), to drive each of the inverter circuit (114 _a, 114 _b).

Thereby, in each of the first series and the second series, the power receiving coil generates an electromotive force by an alternating magnetic field generated by the power feeding coil (that is, by electromagnetic induction), thereby generating alternating current power. That is, the self-powered electric coil transmits electric power to the power receiving coil by mutual magnetic coupling. In this manner, the self-powered device 111 is wirelessly powered to the power receiving device 112.

[About the characteristics of this embodiment]

The wireless power feeding system 1 of the present embodiment has the characteristics of being inexpensive and easily obtaining high output (hereinafter referred to as "first characteristic"), and the feature of suppressing excessive magnetic field radiation (hereinafter referred to as "2nd feature"). Hereinafter, these characteristics will be specifically described.

First, the first feature will be described. As described above, the wireless power feeding system 1 has a plurality of power transmission mechanisms of the first series and the second series in parallel, and the power receiving device 112 combines the powers transmitted by the power transmission mechanisms and outputs them from the output terminal 102. Therefore, even if the power transmission amount in each power transmission mechanism is small, it is possible to easily obtain a high output by synthesizing the transmitted power. For example, when an equivalent power transmission mechanism is applied to each series, if N series are provided, substantially N times of output can be obtained.

Further, according to the wireless power feeding system 1, the power required for each power transmission mechanism can be made small as compared with the case where only one power transmission mechanism is provided. Therefore, parts having low power resistance and low cost can be used as components constituting each power transmission mechanism, and the manufacturing cost of the wireless power feeding system 1 can be suppressed.

Further, in the wireless power feeding system 1, in order to achieve cost reduction and synchronization control, the control circuit 113, the signal receiving circuit 115, and the load modulation circuit 116 are provided only in the first series and are not provided in the second series. Therefore, compared with the case where the circuits (113, 115, 116) are also provided in the second series, the number of parts can be reduced, and the configuration can be simplified.

That is, the present embodiment is not simply a form in which a plurality of wireless power feeding systems illustrated in FIG. 6 are bundled, and the manufacturing cost can be further suppressed by omitting redundant circuit components. The wireless power feeding system 1 has the first feature for the reasons described above.

Next, the second feature will be described. Here, focusing on the direction of the alternating current flowing through the power feeding coil, the directions of the alternating currents in the power feeding coil L1 _a and the power feeding coil L1 _b (adjacent power feeding coils) are always opposite to each other.

That is, for example, the waveform of the alternating current flowing through the power feeding coil L1 _{a and} the alternating current flowing through the power feeding coil L1 _b are based on the current flowing in the left turn direction (even if the right turn is reversed). Synchronized with each other and in opposite phase. Furthermore, in the portion where the respective power feeding coils (L1 _a , L1 _b ) are close (the close portion CS shown in Fig. 2), the directions of the alternating currents of the respective power feeding coils (L1 _a , L1 _b ) are always substantially the same direction. .

Thus, in the present embodiment, the directions of the alternating currents in the adjacent power supply coils are always opposite to each other, and therefore, according to the same principle as the invention of the applicant's prior application (Japanese Patent Application No. 2012-121741), The excess magnetic field radiation (excess electromagnetic field radiation) leaking from the self-feeding coil or the power receiving coil (power feeding, receiving coil) is suppressed.

In other words, when the power feeding device 111 supplies power to the power receiving device 112, _a path (for example, a fraction of a part) of the magnetic flux of the power feeding and receiving coils (L1 _a , L2 _a ) of the first system is bent and sucked. Power to the second system. Receiving coil (L1 _b, L2 _b), by feeding the second system, the part of the magnetic field lines of the receiving coil (L1 _b, L2 _b) of (e.g., about one several minutes) the path bending is drawn through a system of feeding , power receiving coil (L1 _a , L2 _a ). As a result, the power feeding and receiving coils (L1 _a , L2 _a ) of the first system and the power receiving and receiving coils (L1 _b , L2 _b ) of the second system mutually absorb magnetic lines of force, whereby the magnetic lines of force are tightly folded. The situation of expanding to a distant place is suppressed.

Further, referring to Fig. 3, a description will be given of the principle of suppressing excess electromagnetic field radiation according to other points of view. Further, in FIG. 3, schematically represented with a respective receiving coil (L2 _a, L2 _b), flowing through to L1 _a of coil currents Ia, and flowing through a positional relationship between the current Ib of the coil L1 _b of.

It is known that the intensity of a low frequency magnetic field decays inversely proportional to the square of the distance. For example, at the point A near the power receiving coil, the distance from the current Ia is obviously unbalanced from the distance from the current Ib. Therefore, at point A, the magnetic field strength is determined only by the substantially closer current Ia, so that strong magnetic field coupling occurs.

However, for example, at a point B in the distance, the distance from the current Ia is substantially equal to the distance from the current Ib. Therefore, at point B, the two magnetic fields having substantially equal intensities and opposite phases cancel each other out, so that the magnetic field strength is suppressed to be low. As described above, the present embodiment simultaneously satisfies the contradiction that a strong magnetic field coupling occurs in the vicinity of the power receiving coil, and the magnetic field strength is attenuated sharply in the distance.

The wireless power feeding system 1 has the second feature for the reasons described above. By suppressing unwanted magnetic field radiation that leaks to the surroundings, electromagnetic interference to surrounding electronic devices or exposure to magnetic fields of the surrounding human body can be mitigated. Furthermore, the direction of the alternating current in the adjacent power supply coils in the present invention is preferably completely "always opposite", but there may be errors in the range that does not deviate from the purpose of obtaining the second feature (for example, extremely short-lived) The ground is not opposite to each other).

Furthermore, it is known that if a plurality of power transmission mechanisms of a plurality of systems are simply arranged in parallel, parasitic coupling is generally caused between a plurality of power supply coils to hinder the operation. The second feature described above can also be considered as a homeopathic use of the parasitic coupling to obtain an effect of suppressing excessive magnetic field radiation.

2. Second embodiment [The overall composition of the wireless power supply system]

Next, a second embodiment will be described. Fig. 4 is a configuration diagram of the wireless power feeding system 1 of the second embodiment. As shown in FIG. 4, the wireless power feeding system 1 has a power feeding device 111 (wireless power feeding device) and a power receiving device 112 (wireless power receiving device). The wireless power feeding system 1 is constructed in a manner suitable for the Qi standard.

Feeding device 111 includes a DC power supply unit 101, a control circuit 113, each of the inverter circuit (114 _a ~ 114 _c), the signal receiving circuit 115, a switching circuit 123, the capacitors _{(C1 a ~ C1 c, C3} ), and each feeding Coil (L1 _a ~ L1 _c ). Power receiving apparatus 112 includes an output terminal 102, a load modulation circuit 116, each of the rectifier circuit (127 _a ~ 127 _c), each receiving coil (L2 _a ~ L2 _c), and each capacitor (C2 _a ~ C2 _c).

Moreover, as shown in FIG. 4, the wireless power feeding system 1 has the first to third series power transmission mechanisms, and is a mechanism for wirelessly transmitting power from the power feeding device 111 to the power receiving device 112. In the following description, the transmission unit of the first series is simply referred to as the “first series”, and the transmission unit of the second series is simply referred to as the “second series”, and the transmission unit of the third series is simply called "3rd Series".

The first series comprises a control circuit 113, the inverter circuit 114 _a, a signal receiving circuit 115, a load modulation circuit 116, the capacitors _{(C1 a, C2 a, C3} ), to the coil L1 _a, receiving coil L2 _a, And a rectifier circuit 127 _a . The second series circuit includes an inverter 114 _b, each capacitor (C1 _b, C2 _b), a coil L1 _b, receiving coil L2 _b, and the rectifier circuit 127 _b. 3 comprises a series of inverter circuits 114 _c, each capacitor (C1 _c, C2 _c), to the coil L1 _c, receiving coil L2 _c, and the rectifier circuit 127 _c.

In addition, for the elements with the "a" to "c" subscripts in the quotation, the equivalent elements are set in the first series to the third series, the "a" subscript indicates the elements of the first series, and the "b" subscript Indicates the elements of the second series, and the "c" subscript indicates the elements of the third series. As is apparent from FIG. 4, the wireless power feeding system 1 is configured such that each of the first to third series power transmission mechanisms is provided in parallel between the DC power supply unit 101 and the output terminal 102.

The power feeding device 111 and the power receiving device 112 are structurally separated from each other, but the wireless power feeding system 1 is wirelessly capable of positioning the devices by appropriately (in such a manner that the series of power feeding coils and the power receiving coil are closely facing each other). The state of power supply (composed in Figure 4). When the wireless power feeding system 1 is wirelessly powered, the positioning is performed in the above-described manner, and the state after the positioning is maintained to perform wireless power feeding.

The DC power supply unit 101 includes, for example, a battery or an AC adapter connected to a commercial power source, and functions as a DC power supply. DC power supply unit 101 supplying DC power to each of the inverter circuit (114 _a ~ 114 _c).

The inverter circuit 114 _a switching system having a plurality of elements (S1 _a ~ S4 _a) of the inverter circuit of a full bridge configuration. Based inverter circuit 114 _b has a plurality of switching elements (S1 _b ~ S4 _b) of the inverter circuit of a full bridge configuration. The inverter circuit 114 _c system having a plurality of switching elements (S1 _c ~ S4 _c) of the inverter circuit of a full bridge configuration.

Further, in the inverter circuit 114 _a, the end of the switching element S1 _a and S3 _a portion of the DC power supply 101 is connected, and the switching element S2 _a one S4 _a ground. The other end of the switching element S1 _a switching element is directly connected to the other end S2 _a, and is connected to one end of a coil L1 _a sum via a capacitor C1 _a. The other end of the switching element S3 _a connection to the other ends of the switching element S4 _a and to the coil L1 _a.

Further, in the inverter circuit 114 _b, and the switching element S1 _b is connected to the one end S3 _b of the DC power supply unit 101, the switching element S2 _b and S4 _b grounded one. The other end of the switching element S1 _b is directly connected to the other end of the switching element S2 _b and is connected to one end of the power feeding coil L1 _b via a capacitor C1 _b . The other end of the switching element S3 _b is connected to the other end of the switching element S4 _b and the other end to the coil L1 _b.

Further, in the inverter circuit 114 _c, the switching element S1 _c and S3 _c of the end connected to the DC power supply unit 101, the switching element S2 _c and S4 _c grounded one. The other end of the switching element S1 _c is directly connected to the other end of the switching element S2 _c , and is connected to one end of the power feeding coil L1 _c via a capacitor C1 _c . The other end of the switching element S3 _c of the other end connected to the other end of the switching element S4 _c and to the coil L1 _c.

Each inverter circuit (114 _a ~ 114 _c) having the above configuration, each of the switching elements is turned on by the on / off switch, to convert AC power from the DC power supply 101 of the DC power supply unit. The inverter circuit 114 _a sends the AC power generated by the conversion to the power feeding coil L1 _a , and the inverter circuit 114 _b sends the AC power generated by the conversion to the power feeding coil L1 _b , the inverter circuit 114 _c sends the AC power generated by the conversion to the power feeding coil L1 _c .

Conducting each of the switching elements of the inverter circuit (114 _a ~ 114 _c) of the on / off switching by the control system 113 the control circuit. That is, the control circuit 113 to the respective inverter circuit (114 _a ~ 114 _c) is suitably operated in such manner, and generating an output for each of the switching elements of the control signals (G1 ~ G4 ON / OFF switching of ). For example, when each switching element is an FET, the control circuit 113 generates a pulse signal in which the H level and the L level alternately appear as the respective control signals (G1 to G4) and outputs them to the gates of the respective FETs.

Further, the control circuit 113 via the same wiring connected to the switching element S1 _a, S2 _b, and S1 _c, G1 outputs a control signal via the switching element of the wiring and the like. Further, the control circuit 113 via the same wiring connected to the switching element S2 _a, S1 _b, and S2 _c, the wirings via the switching element to the other output control signal G2. Further, the control circuit 113 via the same wiring connected to the switching element S3 _a, S4 _b, and S3 _c, G3 via the switching element to the output control signal of the wirings and the like. Further, the control circuit 113 via the same wiring connected to the switching element S4 _a, S3 _b, and S4 _c, a control signal is output via the switching element G4 which the wirings and the like.

According to the above, each of the switching elements (S1 _a , S2 _b , S1 _c ), the respective switching elements (S2 _a , S1 _b , S2 _c ), and the respective switching elements (S3 _a , S4 _b , S3 _c ) The group and each of the switching elements (S4 _a , S3 _b , and S4 _c ) operate in synchronization. Thus, each of the inverter circuit (114 _a ~ 114 _c) AC output power synchronization with each other.

Further, the inverter circuit of the inverter circuit 114 _a 114 _c-phase of the output AC power with one another. However inverter circuit 114 _b with the other output AC power inverter circuit (114 _a, 114 _c) of the inverter. The reason is that the direction of the alternating current flowing through the power feeding coil L1 _b is opposite to the direction of the alternating current flowing through the other power feeding coils (L1 _a , L1 _c ).

The signal receiving circuit 115 is connected to the power feeding coil L1 _a via the capacitor C3, and receives the wireless signal Sr from the power receiving device 112 side (load modulation circuit 116). In addition, although one part of the transmission power in the first series is used as the driving power of the signal receiving circuit 115, it may be in other forms.

Further, the switch circuit 123 has a function of switching the on/off of the wiring in the middle of the wiring for transmitting the respective control signals (G1 to G4). The switching circuit 123 to a state of the disconnection of the wires (OFF state), the control signals (G1 ~ G4) transmitted to the first series of inverter circuit 114 _a, but not transmitted to the second and third series The series of inverter circuits (114 _b , 114 _c ).

One end of the coil L2 _a via capacitor C2 _a is connected to one input terminal of the rectifier circuit 127 _a subject. And, receiving the other end of the coil L2 _a is connected to the other input terminal of the rectifier circuit 127 _a. One end of the power receiving coil L2 _b is connected to one input terminal of the rectifier circuit 127 _b via a capacitor C2 _b . Further, the other end of the power receiving coil L2 _b is connected to the other input terminal of the rectifier circuit 127 _b . One end of the power receiving coil L2 _c is connected to one input terminal of the rectifier circuit 127 _c via a capacitor C2 _c . And, receiving the other end of the coil L2 _c connected to the other input terminal of the rectifier circuit 127 _c. Further, each of the capacitors (C1 _a to C1 _c , C2 _a to C2 _c ) is inserted into a resonance capacitor before and after the power feeding and receiving coils in order to improve performance.

A load modulation circuit 116 via the capacitor C2 _a is connected to the receiving coil L2 _a, a wireless signal transmitted by a change of load modulation generated Sr. Further, one of the transmission powers in the first series is used as the driving power of the load modulation circuit 116, but may be other forms. As described above, the wireless signal Sr is received by the signal receiving circuit 115 on the power transmitting device 111 side. Thereby, communication related to wireless power feeding can be performed between the power transmitting device 111 and the power receiving device 112.

The rectifier circuit 127 _a converts the AC power transmitted from the power receiving coil L2 _a into DC power, and sends the DC power to the output terminal 102. Further, the rectifier circuit 127 _b from the receiving coil L2 _b transport from the AC power into DC power and DC power fed to the output terminal 102. Further, the rectifier circuit 127 _c from the AC power receiving coil L2 _c from the delivery into DC power and DC power fed to the output terminal 102.

Output terminal 102 is connected to a secondary battery having a receiving (not shown) in the electrical equipment of the electrical apparatus 112, from each of the rectification circuit (127 _a ~ 127 _c) synthesizing and receiving the electric power to be output. Whereby, out of the DC power supplied from each of the rectification circuit (127 _a ~ 127 _c) via a single terminal 102 to the output of the secondary battery, and is used as a drive power to the electrical equipment and the like. In the present embodiment, the output power from the output terminal 102 is supplied to the secondary battery, but the supply destination of the output power or the like is not limited to this form.

FIG. 5 exemplifies a structure (mounting form) in the vicinity of each of the power feeding coils (L1 _a to L1 _c ) in the power feeding device 111. Each of the power feeding coils (L1 _a to L1 _c ) is a circular coil formed by winding a copper wire in the same direction, and is attached to the surface of the magnetic body plate 504, thereby being disposed on substantially the same plane. Further, each of the power feeding coils (L1 _a to L1 _c ) is arranged in the order of L1 _a , L1 _b , and L1 _c , and is disposed in such a manner that the power feeding coils L1 _a and L1 _b are approximated in a substantially adjacent manner, and The power feeding coils L1 _b and L1 _{c are} in close proximity. Further, both ends of the respective power feeding coils (L1 _a to L1 _c ) are soldered to wiring patterns (P511, P512, P521, P522, P531, and P532) provided on the circuit board 503.

P511 is connected to the wiring pattern between the switching element S3 _a and S4 _a, the wiring pattern P512 connected to one end of the capacitor C1 _a. P521 wiring pattern connected to the switch S3 _b between the one end and S4 _b, the wiring pattern P522 is connected to the capacitor element C1 _b. P531 is connected to the wiring pattern between the switching element S3 _c and S4 _c, the wiring patterns P532 connected to one end of the capacitor C1 _c.

Further, each of the wiring patterns (P511, P512, P521, P522, P531, and P532) is disposed on the surface side of the circuit board 503. Unlike the case of the first embodiment, the three-dimensional intersection of the wiring patterns is not employed.

Further, each of the receiving coil (L2 _a ~ L2 _c) in the manner described above the power receiving state of positioning the feeding device 111 device 112 and, in a manner facing the same series to the coil, disposed on substantially the same plane.

When the wireless power feeding system 1 to the power control circuit 113 outputs control signals (G1 ~ G4), each of the driving inverter circuit (114 _a ~ 114 _c). Thereby, in each of the first to third series, the power receiving coil generates an electromotive force by an alternating magnetic field generated by the power feeding coil (that is, by electromagnetic induction), thereby generating alternating current power. That is, the self-powered electric coil transmits electric power to the power receiving coil by mutual magnetic coupling. In this manner, the self-powered device 111 is wirelessly powered to the power receiving device 112.

Further, when the power is not supplied from the power feeding device 111 to the power receiving device 112, the signal receiving circuit 115 communicates with the load modulation circuit 116 to monitor whether or not the predetermined power-on start condition has been satisfied. The power-on starting condition is a predetermined condition that is satisfied after the preparation of the power-on is completed. For example, when the power receiving device (the Qi standard) that is the power receiving target is appropriately positioned, and the power feeding condition is determined based on the communication result, the power feeding start condition is satisfied.

Further, the power supply device 111 can be the monitor (in communication with a load modulation circuit 116), and therefore, even in standby, to a certain extent also requires that the inverter circuit 114 _a (first receiving circuit 115 is connected to the signal 1 series inverter circuit) drive. Thus, at standby, the control circuit 113 sends the manner described above for each of the control signal of the inverter circuit 114 _a of the drive (G1 ~ G4).

However, in the standby, the switch circuit 123 is in the off state, whereby not the second series and the third series inverter circuit (114 _b, 114 _c) transmitting a control signal (G1 ~ G4), the inverting such The circuit (114 _b , 114 _c ) stops. That is, in standby, the power supply device 111 of the first inverter series 114 _a driving circuit, on the other hand, the remaining of the two inverter circuits (114 _b, 114 _c) is stopped. Thereby, the power feeding device 111 can eliminate unnecessary driving of the inverter circuit, thereby suppressing standby power as much as possible.

Then, when the power-on start condition is satisfied, the power feeding device 111 transitions from the standby state to the normal operating state. That is, the power supply device 111 release the off state of the switch circuit 123, so that all of the inverter circuit (114 _a ~ 114 _c) driven to appropriately perform wireless power receiving apparatus 112 to the feeding.

Further, similarly to the case of the first embodiment, the wireless power feeding system 1 of the second embodiment has the first feature of being inexpensive and easily obtaining high output, and the second feature of suppressing excessive magnetic field radiation.

Further, with respect to the second characteristic, in the case when the second aspect of the embodiment, a coil L1 _a and L1 _b adjacent to the coil, and a coil L1 _b adjacent to the coil L1 _c. Therefore, in the second embodiment, the directions of the alternating currents in the power feeding coil L1 _a and the power feeding coil L1 _b are always opposite to each other, and the directions of the alternating currents in the power feeding coil L1 _b and the power feeding coil L1 _c are always opposite to each other.

That is, for example, the waveform of the alternating current flowing through the power feeding coil L1 _a and the waveform of the alternating current flowing through the power feeding coil L1 _b are mutually based on the current flowing in the left turn direction (even in the right turn direction). The relationship between the synchronous phase and the opposite phase is the same, and the waveform of the alternating current flowing through the power feeding coil L1 _b and the waveform of the alternating current flowing through the power feeding coil L1 _c are synchronized with each other and in opposite phases.

Furthermore, in the portion where the respective power feeding coils (L1 _a , L1 _b ) are close (the close portion CS1 shown in FIG. 5), the directions of the alternating currents of the respective power feeding coils (L1 _a , L1 _b ) are always substantially the same direction. . Further, the direction of the alternating current (shown in FIG. 5 of the closest part CS2), each to a coil (L1 _b, L1 _c) currents to each of a coil (L1 _b, L1 _c) close the moiety is always substantially the same with one another direction.

As described above, in the second embodiment, there are _a pair of power supply coils of a power supply coil in which a complex array (here, _a pair of power supply coils of L1 _a and L1 _b and a pair of power supply coils of L1 _b and L1 _c ) are adjacent to each other. However, for all pairs of power supply coils, the direction of the alternating current is always opposite to each other. Therefore, the excess magnetic field radiation can be suppressed as much as possible.

3. Other

As described above, the power feeding device 111 of each embodiment includes N power feeding coils of the first to Nth series, and wirelessly supplies power to the power receiving device 112 including the N series power receiving coils of the first to Nth series. More specifically, the power feeding device 111 causes an alternating current to flow through each of the N power feeding coils, and generates electromagnetic induction by the power feeding coil and the power receiving coil in each series, thereby performing the wireless power feeding. Further, in the example of the first embodiment, N = 2, and in the example of the second embodiment, N = 3, but N may be set to 4 or more according to the configuration of each embodiment.

Further, in the power feeding device 111, the N power feeding coils are disposed on substantially the same plane, and the directions of the alternating currents in the adjacent power feeding coils are always opposite to each other. Therefore, according to the power feeding device 111, it is easy to realize an inexpensive and high-output wireless power feeding system, and it is possible to suppress unnecessary magnetic field radiation.

Further, the wireless power feeding system 1 of each embodiment includes the power transmitting device 111 and the power receiving device 112 including the N series power receiving coils of the first to Nth series, and performs the above-described state in which the power receiving device 112 and the power feeding device 111 are positioned. Wireless power. Further, each of the N power receiving coils is disposed on substantially the same plane so as to face the same series of the power feeding coils in a state in which the positioning is performed.

More specifically, the power feeding device 111 is formed in such a manner as to have the first series N inverter circuits of the Nth series and control circuits 113 for controlling the respective operations of the N inverter circuits, and each of the N inverter circuits converts DC power into AC power And sending the AC power to the above-mentioned power feeding coil of the same series.

Further, the power receiving device 112 is formed to include N rectifier circuits of the first to Nth series and the output terminal 102, and each of the N rectifier circuits is from the same series of the power receiving coils The received AC power is converted into DC power, and the DC power is sent to the output terminal.

Further, in the wireless power feeding system 1 of the embodiment, the load modulation circuit 116 that transmits a wireless signal by load modulation is provided in the power receiving device 112, and the signal receiving circuit 115 that receives the wireless signal is provided in the power transmitting device 111. Communication is performed between the load modulation circuit 116 and the signal receiving circuit 115. Thereby, information transmission related to wireless power feeding can be performed between the power feeding device 111 and the power receiving device 112. Further, the configuration is simplified by setting the number of the load modulation circuit 116 and the number of the signal receiving circuits 115 to one.

Further, when the wireless power feeding system 1 of the second embodiment does not perform the wireless power standby, the communication monitoring is performed using the communication monitoring condition. Further, the signal receiving circuit 115 is connected to the power feeding coil of the Kth series, and the load modulation circuit 116 is connected to the power receiving coil of the Kth series. Further, in the example of the second embodiment, K = 1, but K can be set to any number from 1 to N.

Further, in the standby mode, the control circuit 113 of the second embodiment drives the inverter circuit of the Kth series, and stops the remaining N-1 inverter circuits, and the above-mentioned power supply is satisfied. In the case of the start condition, all of the above N inverter circuits are driven. Thereby, standby power can be suppressed as much as possible.

Further, the wireless power feeding system 1 is suitable, for example, for a mobile electric device. In this case, the electric device is configured to include the power receiving device 112 and the secondary battery (connected to the output terminal 102), and is driven by the electric power that has been charged to the secondary battery. Further, the power feeding device 111 is provided in a charger corresponding to the electric device. According to this aspect, the secondary battery in the electrical device can be charged by bringing the electrical device close to the charger (for example, placing the electrical device on the charger). However, the application target or the like of the wireless power feeding system 1 is not limited to this form.

Further, various changes can be added to the configuration of the present invention without departing from the scope of the invention. That is, the above embodiments are considered to be illustrative and not limiting. It is to be understood that the technical scope of the present invention is not limited by the description of the embodiments, but is intended to be in the scope of the claims.

[Industrial availability]

The present invention can be utilized in a wireless power feeding system of an electromagnetic induction type or the like.

1‧‧‧Wireless power system

101‧‧‧DC Power Supply Department

102‧‧‧Output terminal

111‧‧‧Power supply

112‧‧‧Power-receiving device

113‧‧‧Control circuit

114 _a , 114 _b ‧‧‧Inverter circuit

115‧‧‧Signal receiving circuit

116‧‧‧Load modulation circuit

127 _a , 127 _b ‧‧‧Rectifier circuit

C1 _a , C1 _b , C2 _a , C2 _b , C3‧‧‧ capacitors

G1~G4‧‧‧ control signal

L1 _a , L1 _b ‧‧‧ power coil

L2 _a , L2 _b ‧‧‧ power receiving coil

S1 _a ~S4 _a , S1 _b ~S4 _b ‧‧‧Switching elements

Sr‧‧‧ wireless signal

Claims (5)

A power feeding device comprising N power feeding coils of a first series to an Nth series (N is an integer of 2 or more), and wirelessly receiving power receiving devices including N power receiving coils of the first series to the Nth series And supplying an alternating current to each of the N power feeding coils, and generating electromagnetic induction by the power feeding coil and the power receiving coil in each series, thereby performing the wireless power feeding; each of the N power feeding coils They are disposed on substantially the same plane, and the directions of the alternating currents in the adjacent ones of the power feeding coils are always opposite to each other. A wireless power feeding system, comprising: the power feeding device of claim 1; and the power receiving device, comprising: N power receiving coils of the first series to the Nth series; wherein the power receiving device and the power feeding device are positioned And performing the wireless power feeding; and each of the N power receiving coils is disposed on substantially the same plane so as to face the same series of the power feeding coils in the positioned state. The wireless power feeding system of claim 2, wherein the power feeding device comprises: N inverter circuits of the first series to the Nth series; and a control circuit that controls respective operations of the N inverter circuits; Each of the N inverter circuits converts DC power into AC power, and the AC power is sent to the same series of the power feeding coils; the power receiving device includes: N rectifier circuits of the first series to the Nth series; and output terminals; and each of the N rectifier circuits converts AC power received from the same series of the power receiving coils into DC power, and sends the DC power Formed to the above output terminal. The wireless power feeding system of claim 3, wherein a load modulation circuit for transmitting a wireless signal by load modulation is disposed in the power receiving device, and a signal receiving circuit for receiving the wireless signal is disposed in the power feeding device, and the load is adjusted The variable circuit and the signal receiving circuit communicate with each other; and the number of the load modulation circuit and the number of the signal receiving circuits are respectively set to one. The wireless power feeding system of claim 4 is configured to monitor whether the predetermined power-on starting condition is satisfied by using the communication monitoring when the wireless power-on standby is not performed; and the signal receiving circuit is connected to the K-series (K is 1 to N). In the above-described power feeding coil, the load modulation circuit is connected to the power receiving coil of the Kth series, and the control circuit drives the inverter circuit of the Kth series in the standby state. The remaining N-1 inverter circuits are stopped, and all of the N inverter circuits are driven when the power supply start condition is satisfied.