JP2010130835A - Noncontact power transmission apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact, light-weight noncontact power transmission apparatus which achieves proper radio communication without any influence of transmitted/received power waves as well as noncontact power transmission/reception. <P>SOLUTION: A power-receiving means 2 transmits/receives information through radio communication and obtains power through electromagnetic induction to charge a secondary battery. The power-receiving means 2 includes a radio communication unit 4b, a control unit 5b, a coil 6c, a coil connection switching unit 7, a power-receiving unit 8, a charge control unit 9, and a secondary battery 10. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a contactless power transmission device that transmits and receives power without contact.

  In recent years, along with the downsizing of electronic components, portable electronic devices typified by mobile phones and portable music players have been widely spread due to the reduction in size and weight. In recent years, portable electronic devices have become more multifunctional and faster, and accordingly, the amount of power required by the electronic devices has been increasing. However, in general, portable electronic devices do not have a dedicated adapter and are driven by the power charged in the built-in secondary battery, and the secondary battery must be charged each time the power of the secondary battery is insufficient. Don't be.

  In general, the charging of the secondary battery of the portable electronic device is performed by bringing the charging terminal of the portable electronic device and the charging terminal of the charging base (cradle) into contact, electrically connecting them, and supplying power from the charging base 2 Charge the next battery.

  However, in the charging method in which the charging terminals are connected in contact with each other, charging may not be possible due to contamination of the charging terminals or entry of foreign matter between the charging terminals, and non-contact power supply is desired.

  In response to this demand, Patent Document 1 discloses a power transmission device and a power reception device that supply power without contact without using a charging terminal and charge a secondary battery built in a portable electronic device.

  In the power transmission device and the power reception device described in Patent Document 1, the common cradle includes a power transmission module including a coil therein and a commercial voltage is supplied, and the PDA includes a power reception module including a coil therein. By mounting the PDA on the shared cradle, magnetic coupling occurs between the coil in the PDA and the coil in the shared cradle, and both ends of the coil in the PDA are based on the commercial voltage supplied to the shared cradle. A voltage is induced to supply power to the PDA. At this time, data transmission can be performed between the PC and the PDA by adopting a configuration in which data communication is possible between the shared cradle and the PC.

JP 2006-141170 A

  When it is necessary to exchange information regarding power transmission / reception between the power transmission device and the power reception device, as described in Patent Document 1, a means for exchanging information using wireless communication is used as an electromagnetic induction of a coil. May be provided in a device for transmitting and receiving power using

  Furthermore, the power receiving device that is the device on the portable side is desired to be as small and light as possible. For example, the power receiving coil and the wireless communication coil are combined to reduce the number of parts of the device. A reduction in size and weight can be achieved.

  When using both a power receiving coil and a wireless communication coil, for example, as described in Patent Document 1, a signal composed of information related to power transmission / reception is superimposed on a power wave or a carrier wave to supply power, or There are a method of performing power and communication simultaneously by modulating and transmitting and receiving, and a method of simultaneously performing wireless communication during power transmission and reception by using both a power wave for transmitting and receiving power and a carrier wave for wireless communication.

  However, in a method of superimposing or modulating a signal on a power wave or carrier wave, in general, in order to supply power, it is necessary to increase the output of the power wave or carrier wave, and the same power transmission device and power receiving device are in the vicinity. In this case, there is a possibility that interference with nearby devices may occur, and wireless communication may not be performed normally.

  In response to the above problem, if the power wave for transmitting and receiving power and the carrier wave for wireless communication are used in combination, only the output of the power wave for supplying power is increased, and the output of the carrier wave for wireless communication is kept low. Even when the same power transmitting device and power receiving device are in the vicinity, wireless communication can be normally performed.

  However, in the method of using both the power wave for transmitting and receiving power and the carrier wave for wireless communication, in general, since the signal output to be transmitted and received by wireless communication is smaller than the output of the power wave to transmit and receive power, There is a problem that a signal component is buried in a noise component caused by a power wave, and wireless communication cannot be performed correctly.

  The object of the present invention is to solve the above-mentioned problems, achieve miniaturization and weight reduction, perform wireless communication correctly without being affected by the power wave to be transmitted and received, and contactlessly transmit and receive power without contact It is to provide a power transmission device.

  According to the present invention, there is provided a non-contact power transmission device having a power transmission unit and a power reception unit for performing transmission and reception of control information by wireless communication and transmitting and receiving power by electromagnetic induction, and the power transmission unit includes: A first wireless communication unit connected to a first coil that performs wireless communication with the power receiving unit, and a power transmission connected to a second coil that transmits power to the power receiving unit by electromagnetic induction And a first control unit that performs control to start or stop wireless communication by the first wireless communication unit and power transmission by the power transmission unit, and the power receiving unit includes the power transmission unit and the first power transmission unit. A third coil used for wireless communication and power reception, a second wireless communication unit that performs wireless communication with the power transmission unit, a power reception unit that receives power from the power transmission unit, A coil connection switching unit that switches to either the second wireless communication unit or the power receiving unit and connects to the third coil, wireless communication by the second wireless communication unit, and power of the power receiving unit A control section for starting or stopping power transmission, and a second control section for controlling the connection with the third coil by the coil connection switching section, which is provided in advance between the power transmission section and the power reception section. Wireless communication is performed at predetermined time intervals, power transmission / reception between the power transmission unit and the power reception unit is stopped during the wireless communication, and power between the power transmission unit and the power reception unit is terminated after the wireless communication ends. A non-contact power transmission device characterized by restarting power transmission / reception can be obtained.

  FIG. 3 is a diagram for explaining the operation timing of power transmission / reception and wireless communication in the power transmission means and the power reception means constituting the non-contact power transmission apparatus of the present invention, and FIG. FIG. 3B is a diagram illustrating the power transmission unit of the power transmission unit, and FIG. 3C is a diagram illustrating the second wireless communication unit of the power reception unit. FIG. 3D is a diagram illustrating a wireless communication unit, and FIG. 3D is a diagram illustrating a power reception unit of a power reception unit.

  Based on FIG. 3, operation timings of wireless communication and power transmission / reception in the power transmission unit and the power reception unit of the non-contact power transmission apparatus according to the present invention will be described. The first wireless communication unit of the power transmission means shown in FIG. 3A performs wireless communication by driving the circuit of the first wireless communication unit in the first time zone T1, and in the second time zone T2. The circuit of the first wireless communication unit is stopped and wireless communication is not performed. Further, the power transmission unit of the power transmission unit illustrated in FIG. 3B stops the power transmission unit circuit in the first time period T1 and does not transmit power, and does not transmit power in the second time period T2. Part of the circuit is driven to transmit power. Further, the second wireless communication unit of the power receiving means shown in FIG. 3C performs wireless communication by driving the circuit of the second wireless communication unit in the first time zone T1, and performs the second time zone. At T2, the circuit of the second wireless communication unit is stopped and wireless communication is not performed. Further, the power receiving unit of the power receiving unit shown in FIG. 3 (d) does not receive power by stopping the circuit of the power receiving unit in the first time zone T1, and receives power in the second time zone T2. Part of the circuit is driven to receive power. That is, the power transmission unit and the power reception unit do not transmit or receive power during wireless communication. Alternatively, wireless communication is not performed during power transmission / reception.

  Therefore, a power wave having a large output used when power is transmitted / received by electromagnetic induction between coils and a small carrier wave in which data used for wireless communication are superimposed are used as the power transmission means and power of the contactless power transmission device. It does not exist at the same time on the circuit of the power receiving means, and it is possible to prevent the signal component of wireless communication from being buried in the noise component of the power wave, and wireless communication between the power transmitting means and the power receiving means of the non-contact power transmission device It can be ensured, and non-contact power transmission and reception by electromagnetic induction is possible.

  Furthermore, according to the present invention, by combining the coil necessary for wireless communication and the coil necessary for power reception, the number of coils provided in the power receiving means can be reduced to one, and the contactless power transmission device can be reduced in size. And weight reduction are possible.

  According to the present invention, since the power wave used for power transmission / reception and the carrier wave on which the data used for wireless communication are superimposed do not exist at the same time, wireless communication correctly without being affected by the power wave. In addition, by performing power reception and wireless communication in the power receiving means with one coil, it is possible to reduce the number of components constituting the power receiving means, so that non-contact power transmission and reception of power by electromagnetic induction can be performed. A small and lightweight contactless power transmission device can be obtained.

  FIG. 1 is a block diagram showing a configuration of an embodiment of a non-contact power transmission apparatus according to the present invention. Each component of the non-contact power transmission apparatus according to the present invention will be described based on FIG.

  The non-contact power transmission system of the present invention includes a power transmission unit 1 and a power reception unit 2.

  The power transmission unit 1 is a unit that transmits and receives information by wireless communication and transmits power by electromagnetic induction. The power transmission unit 3, the first wireless communication unit 4a, the first control unit 5a, and the first coil 6a. The power transmission unit 3 and the first control unit 5a, the power transmission unit 3 and the second coil 6b, the first wireless communication unit 4a and the first control unit 5a, the first coil 6b. The wireless communication unit 4a and the first coil 6a are electrically connected to each other.

  The power transmission unit 3 generates a predetermined AC power from a DC power supply (not shown) supplied to the power transmission unit 3 using a DC-AC conversion circuit (not shown), and supplies the AC power to the second coil 6b.

  The first wireless communication unit 4a modulates a power-transmittable signal input from the first control unit 5a with a modulation circuit (not shown), superimposes it on a carrier wave, and inputs the signal to the first coil 6a.

  The first wireless communication unit 4a generates a charge request signal by demodulating a carrier wave on which the charge request signal transmitted from the power receiving unit 2 is superimposed by a demodulation circuit (not shown), and generates a charge request signal. Enter.

  The 1st control part 5a produces | generates the power transmission possible signal after starting of the electric power transmission means 1, and inputs it into the 1st radio | wireless communication part 4a.

  In addition, the first control unit 5a determines whether or not there is a charge request signal input from the first wireless communication unit 4a, and when there is a charge request signal, the wireless communication operation of the first wireless communication unit 4a. Is stopped, power transmission to the power receiving means 2 is started using the power transmission unit 3 and the second coil 6b, and when there is no charge request signal, the first wireless communication unit 4a is again transmitted. After the power transmission enable signal is input, it is transmitted to the power receiving means 2 using the first coil 6a.

  The first control unit 5a performs wireless communication with the power receiving means 2 using the first wireless communication unit 4a and the first coil 6a at predetermined time intervals, and performs wireless communication. The power transmission to the power receiving unit 2 by the power transmission unit 3 and the second coil 6b is stopped while the power transmission unit 3 and the second coil 6b are used. Resume power transmission.

  The first coil 6 a transmits a carrier wave on which a signal capable of transmitting power is superimposed to the power receiving means 2.

  Further, the first coil 6a receives the carrier wave on which the charge request signal is superimposed from the power receiving unit 2, and inputs it to the first wireless communication unit 4a.

  The second coil 6b transmits AC power supplied from the power transmission unit 3 to the power receiving unit 2 as a power wave.

  The power receiving means 2 is means for transmitting and receiving information by wireless communication, obtaining power by electromagnetic induction and charging the secondary battery, and includes a second wireless communication unit 4b, a second control unit 5b, and a third coil. 6c, the coil connection switching unit 7, the power receiving unit 8, the charging control unit 9, and the secondary battery 10, and the second wireless communication unit 4b and the coil connection switching unit 7, the second wireless communication unit 4b and the third The terminal 11a of the coil 6c, the second control unit 5b and the coil connection switching unit 7, the second control unit 5b and the power receiving unit 8, the second control unit 5b and the charge control unit 9, and the third coil 6c. The terminal 11b and the coil connection switching unit 7, the terminal 11a and the power receiving unit 8 of the third coil 6c, the coil connection switching unit 7 and the power receiving unit 8, the power receiving unit 8 and the charging control unit 9, and the charging control units 9 and 2 Each of the secondary batteries 10 is electrically connected. Further, the terminal 11a of the third coil 6c is grounded.

  The second wireless communication unit 4b demodulates the received carrier wave on which the power transmission capable signal from the power transmission unit 1 is superimposed by a demodulation circuit (not shown), generates a power transmission possible signal, and inputs the signal to the second control unit 5b. To do.

  The second wireless communication unit 4b modulates the charge request signal input from the second control unit 5b with a modulation circuit (not shown), superimposes it on the carrier wave, and inputs the signal to the third coil 6c.

  The second control unit 5b determines whether or not there is a signal that can be transmitted from the second wireless communication unit 4b. If there is no signal that can be transmitted, the second control unit 5b maintains the reception state. If there is no charge request signal, the charging is stopped, the wireless communication and power reception are terminated, and if there is a charge request signal, the charge request signal is It inputs into the 2nd radio | wireless communication part 4b.

  The second control unit 5b uses the coil connection switching unit 7 after the power receiving unit 2 is activated to connect the terminal 11b of the third coil 6c and the second wireless communication unit 4b, that is, the second When the wireless communication unit 4b side is connected and there is no power transmission enable signal input from the second wireless communication unit 4b, and when no charge request signal is input from the charge control unit, the coil connection switching unit 7 When the connection on the second wireless communication unit 4b side is maintained, a power transmission enable signal is input from the second wireless communication unit 4b, and a charge request signal is input from the charge control unit, the coil connection switching unit 7 Is switched from the connection on the second wireless communication unit 4b side to the connection between the terminal 11b of the third coil 6c and the power receiving unit 8, that is, the connection on the power receiving unit 8 side.

  Furthermore, when the power from the power transmission means 1 is continuously supplied to the power receiving unit 8, the second control unit 5 b maintains the connection on the power receiving unit 8 side with the coil connection switching unit 7, and transmits power. When the power supply from the means 1 to the power receiving unit 8 is stopped, the coil connection switching unit 7 is used to switch to the connection on the second wireless communication unit 4b side.

  The third coil 6c receives a carrier wave on which a power transmission enable signal is superimposed and inputs the received carrier wave to the second wireless communication unit 4b.

  The third coil 6 c transmits the carrier wave on which the charge request signal is superimposed to the power transmission unit 1.

  The third coil 6 c receives the power wave transmitted from the power transmission unit 1 as AC power and supplies it to the power receiving unit 8.

  The coil connection switching unit 7 includes a switch such as an FET (field effect transistor), for example, and connects the third coil 6c and the power receiving unit 8, and the third coil 6c and the second wireless communication unit 4b. Is switched according to the instruction of the second control unit 5b.

  The power receiving unit 8 converts AC power received by the third coil 6c into DC power by an AC-DC conversion circuit (not shown) and supplies the DC power to the charging control unit 9, and also provides continuous supply of AC power. The presence or absence is notified to the second control unit 5b.

  The charging control unit 9 always detects the surface temperature of the secondary battery 10 with a temperature sensor (not shown), and further constantly detects the power reception state of the secondary battery 10 with a current voltmeter (not shown). Is less than the predetermined temperature and the charging rating is not reached, the charging request signal is generated, the charging request signal is input to the second control unit 5b, and the direct current supplied from the power receiving unit 8 is supplied Is supplied to the secondary battery 10. Further, when the surface temperature of the secondary battery 10 is equal to or higher than a predetermined temperature, or when the charging rating of the secondary battery has been reached, a charging request signal is not generated and wireless communication is performed by the second control unit 5b. And stop receiving power.

  The secondary battery 10 stores the DC power supplied from the charging control unit 9, and further uses the stored DC power as power for driving the power receiving means 2 and for driving peripheral circuits (not shown). Use.

  FIG. 2 is a flowchart for explaining an embodiment of the non-contact power transmission apparatus of the present invention. Based on FIG. 2, wireless communication and power transmission / reception according to the non-contact power transmission apparatus of the present invention are performed. The operation will be described.

  After the power transmission means 1 is activated, the wireless communication of the first wireless communication unit 4a already described in FIG. 1 is started (step S101), and the first wireless communication unit 4a starts the first communication already described in FIG. The power transmission enable signal generated by the control unit 5a is modulated by a modulation circuit (not shown) and transmitted to the power receiving means 2 using the first coil 6a already described in FIG. 1 (step S102).

  At the same time, after the power receiving means 2 is activated, the coil connection switching unit 7 already described with reference to FIG. 1 switches the coil connection to the connection on the second wireless communication unit 4b side (step S118), and then already has FIG. The wireless communication of the second wireless communication unit 4b described in (4) is started (step S108), and the second wireless communication unit 4b uses the third coil already described in FIG. 6c (step S109), the second control unit 5b already described with reference to FIG. 1 determines whether or not there is a transmittable signal demodulated by a demodulation circuit (not shown) of the second wireless communication unit 4b (step S109). S110) If there is no signal that can transmit power (step S110-None), charging of the power receiving means 2 is stopped (step S119), and the charging operation of the power receiving means 2 is terminated.

  Furthermore, if there is a signal that can transmit power (step S110-present), the second control unit 5b determines whether or not there is a charge request signal input from the charge control unit 9 already described with reference to FIG. 1 (step S111). If there is no charge request signal (step S111-None), the charging of the power receiving means 2 is stopped (step S119), and the charging operation of the power receiving means 2 is terminated.

  Furthermore, if there is a charge request signal (step S111-Yes), the charge request signal is modulated by a modulation circuit (not shown) of the second wireless communication unit 4b and transmitted from the third coil 6c to the power transmission means 1. (Step S112).

  Thereafter, the charging request signal is received from the power receiving unit 2 using the first wireless communication unit 4a and the first coil 6a of the power transmission unit 1 (step S103), and the first wireless communication unit 4a is illustrated. After demodulating the charging request signal by the demodulation circuit that does not, the first controller 5a determines whether or not there is a charging request signal (step S104). If there is no charging request signal (step S104-None), the first control unit 5a again A modulation circuit (not shown) of the wireless communication unit 4a modulates a power transmission enable signal generated by the first control unit 5a, and transmits the modulated signal to the power receiving means 2 using the first coil 6a (step S102). If there is a signal (step S104-present), the wireless communication of the first wireless communication unit 4a is stopped (step S105).

  Subsequently, a predetermined AC power is generated by a DC-AC conversion circuit (not shown) of the power transmission unit 3 already described in FIG. 1 of the power transmission unit 1, and the second coil 6b already described in FIG. 1 is used. AC power is transmitted to the power receiving means 2 (step S106). Further, AC power is continuously transmitted for a predetermined time (step S121), and thereafter AC power transmission of the power transmission unit 3 is stopped (step S107), and the first radio is again transmitted. Wireless communication of the communication unit 4a is started (step S101).

  At the same time, the coil connection switching unit 7 already described in FIG. 1 of the power receiving means 2 switches the coil connection to the connection on the power receiving unit 8 side (step S113), and then uses the third coil 6c. Then, AC power transmitted from the power transmission means 1 is received by the power receiving unit 8 (step S114).

  Further, the power receiving unit 8 determines whether or not AC power is continuously supplied (step S115), and notifies the second control unit 5b, and the AC-DC conversion circuit (not shown) of the power receiving unit 8 Convert power to DC power.

  Furthermore, if there is no continuous supply of AC power (step S115-none), the coil connection switching unit 7 switches the coil connection to the connection on the second wireless communication unit 4b side again (step S118). The second wireless communication unit 4b starts wireless communication (step S108).

  Further, if there is a continuous supply of AC power (step S115-present), the charging controller 9 determines whether or not charging is necessary (step S116), and if there is no need for charging (step S116-). No), the charging of the power receiving means 2 is stopped (step S119), and the charging operation of the power receiving means 2 is terminated.

  Further, if there is a need for charging (step S116-present), the DC power converted by the power receiving unit 8 and supplied to the charging control unit 9 is stored in the secondary battery 10, and again the AC power is stored. The presence / absence of continuous supply is determined (step S115).

  With the configuration as described above, it is possible to obtain a small and lightweight non-contact power transmission device that can correctly perform wireless communication without being affected by a power wave and can transmit and receive power in a non-contact manner.

  As mentioned above, although embodiment of this invention was described using drawing, this invention is not restricted to these embodiment, There exists a change of a member and a structure in the range which does not deviate from the meaning of this invention. Are also included in the present invention. For example, in the above-described embodiment, the form of the power receiving means is described using one coil connection switching unit, but it is not always necessary to have such a structure, and a configuration using a plurality of coil connection switching units. Similarly, the embodiment of the present invention is formed. Moreover, in the said embodiment, although the form of the electric power receiving means was demonstrated using the secondary battery and the charge control part for the electric power transmission means, it does not necessarily need to be such a structure and a secondary battery and charge Even in the configuration without the control unit, the embodiment of the present invention is similarly formed. That is, it is a matter of course that the present invention also includes various modifications and corrections that would be obvious to those skilled in the art.

The block diagram which shows the structure of embodiment of the non-contact electric power transmission apparatus of this invention. The flowchart explaining embodiment of the non-contact electric power transmission apparatus of this invention. FIG. 3A is a diagram for explaining the operation timing of power transmission / reception and wireless communication in the power transmission means and the power reception means constituting the non-contact power transmission apparatus of the present invention, FIG. 3A is the first wireless communication of the power transmission means FIG. 3B is a diagram illustrating the power transmission unit of the power transmission unit, FIG. 3C is a diagram illustrating the second wireless communication unit of the power reception unit, and FIG. FIG. 3 is a diagram illustrating a power receiving unit of a power receiving unit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electric power transmission means 2 Electric power reception means 3 Electric power transmission part 4a, 4b Wireless communication part 5a, 5b Control part 6a, 6b, 6c Coil 7 Coil connection switching part 8 Electric power reception part 9 Charging control part 10 Secondary battery 11a, 11b Terminal T1, T2 Time zones S101, S102, S103, S104, S105, S106, S107, S108, S109, S110, S111, S112, S113, S114, S115, S116, S117, S118, S119, S120, S121 Steps

Claims (1)

A non-contact power transmission apparatus having power transmission means and power reception means for performing transmission and reception of control information by wireless communication and transmitting and receiving power by electromagnetic induction,
The power transmission means is
A first wireless communication unit connected to a first coil for performing wireless communication with the power receiving means;
An electric power transmission unit connected to a second coil for transmitting electric power to the electric power receiving means by electromagnetic induction;
A first control unit that performs control to start or stop wireless communication by the first wireless communication unit and power transmission by the power transmission unit;
The power receiving means is
A third coil used for wireless communication with the power transmission means and power reception;
A second wireless communication unit for performing wireless communication with the power transmission means;
A power receiving unit for receiving power from the power transmitting means;
A coil connection switching unit that switches to either the second wireless communication unit or the power receiving unit and connects to the third coil;
Control for starting or stopping wireless communication by the second wireless communication unit and power transmission by the power receiving unit, and second control for controlling connection with the third coil by the coil connection switching unit Part
Wireless communication is performed at predetermined time intervals between the power transmission unit and the power reception unit. During wireless communication, power transmission / reception between the power transmission unit and the power reception unit is stopped, and wireless communication is performed. A non-contact power transmission apparatus that resumes power transmission / reception between the power transmission unit and the power reception unit after completion.

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