KR20190020167A - Device and system for power transmission - Google Patents

Abstract

The power transmission apparatus includes a transmission unit and a detection unit. The power transmission unit is configured to transmit power wirelessly. The detecting unit is operatively connected to the transmitting unit and is configured to detect an object within a range from the transmitting unit based on a change in impedance near the transmitting unit.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a power transmission apparatus,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present disclosure relates to a system for performing non-contact power supply (transmission) with respect to a power supply target device (an electronic device, etc.), and a device applied to the system.

2. Description of the Related Art In recent years, a power supply system (non-contact power supply system or wireless charging system) that performs non-contact power supply (transmission) to a CE device (consumer electronic device) such as a cellular phone or a portable music player has received attention. Thus, instead of starting the charging by inserting (connecting) the connector of the power source device such as the AC adapter into the device, it is possible to charge the electronic device (secondary side device) only on the charging tray (primary side device) . That is, terminal connection between the electronic device and the charging tray becomes unnecessary.

As a method for performing the noncontact power supply as described above, an electromagnetic induction method is well known. In recent years, a non-contact type power supply system using a method called a magnetic resonance method has been attracting attention. Such a non-contact type power feeding system is disclosed in, for example, Patent Documents 1 to 3.

Japanese Patent No. 3179802 Japanese Patent Laid-Open No. 2008-167582 Japanese Patent Application Laid-Open No. 2010-119251

Further, in the non-contact power supply system as described above, the power supply unit (primary device) is not allowed to discriminate whether or not the power supply target device (secondary side device) is in the vicinity (in the vicinity of the power supply unit; The power supply unit maintains the power supply, causing useless power consumption.

Each of Patent Documents 1 to 3 proposes a technique for detecting whether or not a feed target device exists in the vicinity of the power feed unit. However, for example, since the configuration and the technique are complicated, there is a disadvantage that the convenience is lacking.

Therefore, it is desirable to propose a technique capable of conveniently detecting the feeding target device during transmission using a magnetic field (non-contact feeding).

It is desirable to provide a device and a power supply system capable of conveniently detecting a power feeding target device when performing power transmission using a magnetic field.

A power transmission apparatus according to an embodiment of the disclosure includes a power transmitting section configured to transmit power wirelessly and a power transmitting section operatively connected to the power transmitting section and configured to receive power within a range from the power transmitting section based on a change in impedance near the power transmitting section And a detection unit configured to detect an object.

The transmission system according to the embodiment of the present disclosure includes a transmission apparatus and a reception apparatus. The power transmission apparatus includes a power transmitting section configured to transmit power wirelessly and a power receiving section that is operatively connected to the power transmitting section and configured to detect a receiving apparatus within a range from the power transmitting section based on a change in impedance near the power transmitting section And a detection unit. The receiving apparatus includes a power receiving unit configured to receive the power wirelessly and a load operatively connected to the power receiving unit and configured to perform an operation based on the received power.

In the power transmission apparatus and the system according to the embodiments of the present disclosure, it is detected whether or not the power feeding target device by the power transmission unit exists in the vicinity by using the change in impedance near the power transmission unit. Thereby, it is possible to detect the feeding target device even if the configuration and technique are not complicated, for example.

According to the power transmission apparatus and system of the present disclosure, it is detected whether or not the power feeding target device by the power transmission unit exists in the vicinity by using a change in impedance near the power transmission unit. Therefore, for example, even if the configuration and the technique are not complicated, it is possible to detect the feeding target device. Therefore, when the transmission portion is performed using the magnetic field, it becomes possible to conveniently detect the feeding target device.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and are intended to provide further explanation of the claimed technique.

The accompanying drawings are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and, together with the specification, serve to explain the principles of the art.
1 is a perspective view showing an external configuration example of a power supply system according to a first embodiment of the present disclosure;
Fig. 2 is a block diagram showing a detailed configuration example of the power supply system shown in Fig. 1. Fig.
3 is a circuit diagram showing a detailed configuration example of a part of the block shown in Fig.
4 is a flowchart showing an operation example of the power supply unit according to the first embodiment.
5 is a timing chart showing an example of a detection period and a non-detection period of the secondary side apparatus.
6A and 6B are characteristic diagrams for explaining a change in impedance characteristic depending on the presence or absence of a secondary device and a metal foreign object.
7 is a timing waveform chart showing an example of a control signal for the high-frequency power generation circuit.
8A and 8B are characteristic diagrams for explaining the change of the harmonic component according to the duty ratio of the control signal.
Fig. 9 is a characteristic diagram for explaining a change in the impedance characteristic according to the change of the harmonic component.
10 is a timing chart showing an example of a power supply period and a communication period.
11 is a block diagram showing a configuration example of a power supply system according to the second embodiment.
12 is a flowchart showing an example of the operation of the power supply unit according to the second embodiment.
Figs. 13A and 13B are timing diagrams showing detection periods and non-detection periods according to Modifications 1 and 2. Fig.
Figs. 14A and 14B are timing charts showing detection periods and non-detection periods according to Modifications 3 and 4. Fig.
Figs. 15A and 15B are timing diagrams showing detection periods and non-detection periods according to Modifications 5 and 6. Fig.

Hereinafter, embodiments of the disclosure will be described in detail with reference to the drawings. It should also be noted that the description is provided in the following order.

1. First Embodiment (Example of Using Impedance Determined from AC Current and AC Voltage)

2. Second Embodiment (Example of Using DC Resistance Determined from DC Current and DC Voltage)

3. Modifications common to the first and second embodiments

 Modifications 1 and 2 (an example of using plural kinds of values for the frequency of the control signal, respectively)

 Modifications 3 and 4 (an example in which a plurality of types of values are used for duty ratios of control signals)

 Modifications 5 and 6 (Example of using plural kinds of values for the frequency and duty ratio of the control signal, respectively)

4. Other variations

≪ First Embodiment >

[Entire Configuration of Power Supply System (4)

Fig. 1 shows an external configuration example of a power supply system (power supply system 4) according to the first embodiment of the present disclosure, and Fig. 2 shows an example of the block configuration of the power supply system 4. As shown in Fig. The power supply system 4 is a system (non-contact power supply system) that performs power transmission (power supply or power supply) in a non-contact manner by using a magnetic field (for example, using electromagnetic induction or magnetic resonance; The power supply system 4 includes a power supply unit 1 (primary side device), one or a plurality of electronic devices (here, two electronic devices 2A and 2B) serving as power supply target devices, Device).

In this power feeding system 4, for example, as shown in Fig. 1, placing the electronic devices 2A and 2B on (or close to) a feed surface S1 (feed surface) in the power feeding unit 1 , Power is supplied from the power feeding unit 1 to the electronic devices 2A and 2B. Considering the case where the electronic devices 2A and 2B are simultaneously or time-sequentially transmitted (sequential), the power supply unit 1 is configured such that the area of the feed surface S1 is larger than the area of the electronic devices 2A and 2B (Tray-shaped).

(Power supply unit 1)

The power feeding unit 1 is a unit (charging tray) that performs power transmission to the electronic devices 2A and 2B using a magnetic field as described above. 2, the power supply unit 1 includes a power supply unit 110, a power supply circuit 111, a high frequency power generation circuit (AC signal generation circuit) 112, a current-voltage detection Unit 113, a control unit 114, and a power transmission unit 11 having a capacitor C1 (capacitive element). Among them, the current-voltage detection unit 113 and the control unit 114 correspond to the specific example of the "detection unit" in the present disclosure, and the control unit 114 corresponds to the specific example of the "control unit" Respectively.

The power transmission unit 110 is configured to include a power transmission coil (primary side coil) L1 and the like to be described later. The power transmitting unit 110 transmits power to the electronic devices 2A and 2B (more specifically, a power receiving unit 210 described later) using a magnetic field by using the power transmission coil L1 and the capacitor C1. Specifically, the power transmitting unit 110 has a function of radiating a magnetic field (magnetic flux) from the feeder surface S1 toward the electronic devices 2A and 2B. It should be noted that the detailed configuration of the transmission unit 110 will be described later (FIG. 3).

The power supply circuit 111 generates a predetermined DC voltage based on, for example, power (AC power or DC power) supplied from a power supply source 9 outside the power supply unit 1, And outputs a voltage to the high-frequency power generation circuit 112. The power supply circuit 111 is configured to include, for example, a DC-DC converter or an AC-DC converter. It should be noted that this power supply circuit 111 may not be provided.

The high frequency electric power generating circuit 112 is a circuit for generating a predetermined high frequency electric power (AC signal) used for transmitting electric power in the electric power transmitting section 110 based on the DC voltage outputted from the electric power source circuit 111. The high-frequency power generation circuit 112 is configured using, for example, a switching amplifier described later. It should be noted that the detailed configuration of the high-frequency power generation circuit 112 will also be described later (FIG. 3).

The current-voltage detecting unit 113 has a current detecting unit 113I and a voltage detecting unit 113V to be described later and detects an alternating current (current) in the vicinity of the power transmitting unit 110 (here the load side of the high- (Current I1) and an AC voltage (voltage V1), respectively. It should be noted that the detailed configuration of the current-voltage detection unit 113 will also be described later (FIG. 3).

The control unit 114 has a function of controlling the operations of the power supply circuit 111 and the high frequency power generation circuit 112, respectively. Specifically, the control unit 114 drives the high-frequency power generation circuit 112 using the control signal CTL having a predetermined frequency and a predetermined duty ratio, as will be described later in detail. Based on the current I1 and the voltage V1 detected in the current-voltage detection unit 113, the control unit 114 controls the power feeding target device (secondary side device; here, the electronic device 2A and 2B) exist in the vicinity (in the vicinity of the feeder surface S1; for example, in a power-feedable area, the same applies hereinafter). Specifically, as will be described later in detail, the control section 114 controls the change in the impedance (in this case, the load impedance of the high-frequency power generation circuit 112 (switching amplifier described later)) in the vicinity of the power transmission section 110 To detect the feeding target device. Here, this load impedance is an impedance of a load connected to a switching amplifier to be described later, and is determined by the alternating current (current I1) and the AC voltage (voltage V1) described above. It should be noted that the control unit 114 is, for example, a microcomputer.

The capacitors C1 are arranged to be electrically connected in parallel or in series and parallel combination to the power transmission coil L1.

(Electronic devices 2A and 2B)

The electronic devices 2A and 2B are, for example, a stationary electronic device represented by a television receiver, a portable electronic device including a rechargeable battery (battery) represented by a cellular phone and a digital camera, and the like. For example, as shown in Fig. 2, each of these electronic devices 2A and 2B includes a power receiving unit 21 and a power supply unit 21 for performing a predetermined operation (A function of performing a function). The power reception unit 21 includes a power receiver 210, a rectification and smoothing circuit 211, a voltage stabilization circuit 212 and a capacitor (capacitive element) C2.

The power receiver 210 is configured to include a power reception coil (secondary coil) L2. The power receiver 210 has a function of receiving power transmitted from the power transmitting unit 110 in the power feeding unit 1 by using the power receiving coil L2 and the capacitor C2. Note that the configuration of the power receiver 210 will also be described later in detail (FIG. 3).

The rectifying and smoothing circuit 211 is a circuit for generating DC power by rectifying and smoothing the power (AC power) supplied from the power receiver 210.

The voltage stabilizing circuit 212 is a circuit for performing a predetermined voltage stabilization operation based on the DC power supplied from the rectifying and smoothing circuit 211 to charge a battery (not shown) in the load 22. [ It should be noted that such a battery is configured using a rechargeable battery (secondary battery) such as a lithium ion battery, for example.

The capacitors C2 are arranged so as to be electrically connected in parallel or in series and in parallel and connected to the power reception coil L2.

[Detailed Configuration of Elements Including High-Frequency Power Generation Circuit 112 and Current-Voltage Detection Unit 113]

3 is a circuit diagram showing the configuration of the power supply unit 110, the capacitor C1, the high frequency power generation circuit 112, the current-voltage detection unit 113 (the current detection unit 113I and the voltage detection unit 113V) C2 of Fig.

The power transmission unit 110 has the power transmission coil L1, and the power reception unit 210 has the power reception coil L2. As described above, the power transmission coil L1 is a coil used for performing power transmission (generating a magnetic flux) by using a magnetic field. On the other hand, the power reception coil L2 is a coil used to receive power transmitted from the power transmission unit 110 (from the magnetic flux).

The high frequency electric power generating circuit 112 is a circuit for generating a high frequency electric power (AC signal) comprising the AC voltage Vac and the alternating current Iac based on the DC voltage Vdc (DC current Idc) supplied from the power supply circuit 111. Here, this high-frequency power generation circuit 112 is configured using a switching amplifier (so-called an E-class amplifier) including one transistor 112T as a switching element. This switching amplifier includes a capacitor 112C used for ripple removal, a coil 112L as a choke coil, and a transistor 112T which is an N-type field effect transistor (FET). One end of the capacitor 112C is connected to one end of the coil 112L as well as the output line from the power supply circuit 111, and the other end is grounded. The other end of the coil 112L is connected to the drain of the transistor 112T and one end of each of the capacitors C1p and C1s at the connection point P21. The source of the transistor 112T is grounded, and the control signal CTL supplied from the control unit 114 is input to the gate as described above. It is to be noted that the other end of the capacitor C1s is connected to one end of the power transmission coil L1, and the other end of the capacitor C1p is grounded. With this configuration, in the high-frequency power generation circuit 112, the transistor 112T performs on / off operation (switching operation including a predetermined switching frequency and a predetermined duty ratio) in accordance with the control signal CTL, A high frequency power is generated.

The current detection unit 113I is a circuit for detecting the above-mentioned current I1 (alternating current), and here, it is disposed between the other end of the power transmission coil L1 and the ground. The current detecting section 113I includes a resistor R11, an amplifier A1, a diode D1, and a capacitor C31. The resistor R11 is disposed between the other end (connection point P22) of the power transmission coil L1 and the ground. In the amplifier A1, one input terminal is connected to the connection point P22, the other input terminal is connected to the ground, and the output terminal is connected to the anode of the diode D1. That is, in this amplifier A1, a potential difference between both ends of the resistor R11 is inputted. The cathode of the diode D1 is connected to one end (the connection point P23) of the capacitor C31, and the other end of the capacitor C31 is grounded. With this configuration, the current detection section 113I outputs the detection result of the current I1 (alternating current) described above from the cathode side (the connection point P23) of the diode D1.

The voltage detection unit 113V is a circuit for detecting the voltage V1 (AC voltage) described above, and is disposed between the connection point P21 and the ground. The voltage detection unit 113V has resistors R21 and R22, an amplifier A2, a diode D2, and a capacitor C32. One end of the resistor R21 is connected to the connection point P21, and the other end is connected to the connection point P24. One end of the resistor R22 is connected to the connection point P24, and the other end is connected to the ground. In the amplifier A2, one input terminal is connected to the connection point P24, the other input terminal is connected to the ground, and the output terminal is connected to the anode of the diode D2. The cathode of the diode D2 is connected to one end (a connection point P25) of the capacitor C32, and the other end of the capacitor C32 is grounded. With this configuration, in the voltage detection unit 113V, the detection result of the voltage V1 (AC voltage) described above is output from the cathode side (junction point P25) of the diode D2.

One end of the capacitor C2p is connected to one end of the power reception coil L2 at the connection point P26 and the other end is connected to the other end of the power reception coil L2 at the connection point P27. One end of the capacitor C2s is connected to the connection point P26 and the other end is connected to one input terminal of the rectifying and smoothing circuit 211. [ It should be noted that the other input terminal of the rectifying and smoothing circuit 211 is connected to the connection point P27.

[Operation and Effect of Power Supply System (4)

(Overview of Overall Operation)

In this power supply system 4, a predetermined high-frequency power (AC signal) for transmission is supplied from the high-frequency power generation circuit 112 to the power transmission coil L1 in the power transmission unit 110 and the capacitor C1. As a result, a magnetic field (magnetic flux) is generated in the power transmission coil L1 in the power transmission unit 110. [ At this time, when each of the electronic devices 2A and 2B as a feeding target device (charging target device) is placed on (or close to) the upper surface (feeding surface S1) of the power feeding unit 1, The coil L1 and the power receiving coils L2 in the electronic devices 2A and 2B come close to each other near the feed surface S1.

As described above, when the power reception coil L2 is disposed close to the power transmission coil L1 generating the magnetic field (magnetic flux), an electromotive force is generated in the power reception coil L2 by the magnetic flux generated by the power transmission coil L1. As a result, the power reception coil L2 side (the secondary side, the electronic devices 2A and 2B side, and the power receiver 210 side) from the power transmission coil L1 side (primary side, power feed unit 1 side and power feeder 110 side) (See the power P1 shown in Figs. 2 and 3).

Next, in the electronic devices 2A and 2B, the AC power received by the power reception coil L2 is supplied to the rectification and smoothing circuit 211 and the voltage stabilization circuit 212, and the following charging operation is performed. That is, after the AC power is converted into the predetermined DC power by the rectifying and smoothing circuit 211, the voltage stabilization circuit 212 performs a voltage stabilization operation based on the DC power, (Not shown) is charged. In this manner, in the electronic devices 2A and 2B, the charging operation based on the power received by the power receiver 210 is performed.

That is, in the present embodiment, terminal connection to, for example, an AC adapter or the like is not required at the time of charging the electronic devices 2A and 2B, and the electronic devices 2A and 2B It is possible to easily start charging (non-contact power feeding is performed) simply by disposing (or bringing the electronic devices 2A and 2B close to each other). This reduces the burden on the user. Such non-contact power feeding has advantages such as deterioration of characteristics due to contact wear, and no fear of electric shock due to human contact with the contact portion. Further, when applied to a device used in a humid environment, such as a toothbrush or an electric shaver, there is an advantage that the contact can be prevented from being corroded by immersion.

(2.2 operation including detecting operation of the secondary side apparatus)

4 to 10, the operation of the power feeding unit 1 (power transmission unit 11) of the present embodiment (detection operation of the electronic devices 2A and 2B (secondary side device) Etc.) will be described. Fig. 4 is a flow chart showing an example of this operation in the power supply unit 1. Fig.

First, the power supply unit 1 performs predetermined startup processing such as initialization of a control terminal (not shown), for example (step S101).

Next, the current-voltage detection unit 113 (the current detection unit 113I and the voltage detection unit 113V) is turned on in the vicinity of the power transmission unit 110 (the load side of the high-frequency power generation circuit 112) (The current I1) and the AC voltage (the voltage V1), respectively (step S102).

Next, the control unit 114 uses the current I1 and the voltage V1 detected by the current-voltage detection unit 113 to calculate the impedance Z1 in the vicinity of the power transmission unit 110 (the high-frequency power generation circuit 112 ) (See Fig. 3) (step S103). Specifically, the absolute value | Z1 | of the impedance Z1 can be obtained by the following equation (1).

| Z1 | = (V1 / I1) ... ... (One)

Subsequently, using the change in impedance Z1 calculated as described above, it is determined by the control unit 114 whether or not the secondary side apparatus (electronic devices 2A and 2B) as the feeding target apparatus exists in the vicinity, .

Specifically, it is preferable that detection of such a feeding target device is performed intermittently at a predetermined interval (non-detection period (detection stop period) Ts), for example, as shown in Fig. This is because continually performing such detection increases the power consumption for the detection operation. However, if the non-detection period Ts is set longer than necessary, the time required for detection of the feeding target device tends to be longer. Therefore, it is necessary to set the non-detection period Ts appropriately. Considering the balance between these facts, it is preferable to allow the interval (non-detection period Ts) between the periods (detection periods Td) for detecting the feeding target device to be arbitrarily controllable, for example, manually or automatically .

The detection of the feeding target device (secondary side device) by the control unit 114 described above is specifically carried out as follows. That is, first, for example, as shown by the code G0 in Fig. 6A, when the secondary side device is not present (absent) in the vicinity, the frequency characteristic of the absolute value of the impedance Z1 | Z1 | Represents a peak at the frequency f0. Here, this resonance frequency f0 can be expressed by the following equations (2) and (3).

f0 = 1 / {2 pi x (L1 C1)} ... ... (2)

C1 = (C1s x C1p) / (C1s + C1p) ... ... (3)

On the other hand, the frequency characteristics of the absolute value | Z1 | of the impedance Z1 when the secondary side device is present (present) as indicated not only by the arrows P3L and P3H in FIG. 6A, (Double hump characteristics). That is, a peak appears at each of the frequency f1H on the high frequency side and the frequency f1L on the low frequency side of the resonance frequency f0. As a result, for example, as shown in Fig. 6 (a), at the frequencies near the frequency f1H and the frequency f1L, the change amount? Z of the absolute value | Z1 | of the impedance Z1 Is a positive value (DELTA Z > 0).

Using this, the control unit 114 determines the presence or absence of the feeding destination apparatus based on the increase amount (variation amount? Z) of the absolute value | Z1 | of the impedance Z1. Specifically, the control unit 114 determines whether or not the feeding destination apparatus exists by comparing the variation amount? Z (> 0) of the impedance with a predetermined threshold value? Zth (step S104). That is, it is determined that the secondary side device (target device) is present in the vicinity (YES) (step S106: YES) if the amount of change DELTA Z (increase amount) is larger than the threshold value DELTA Zth ). On the other hand, if the amount of change? Z (increase amount) is equal to or less than the threshold value? Zth (? Z? DELTA Zth) (step S104: No), it is determined that the secondary device S105).

At this time, it is also possible to distinguish whether or not the object (metal object) different from the object to be fed is present. That is, in the case where a metal object exists (exists) in the vicinity of the power supply unit 1 (the feeder surface S1) as indicated by, for example, the arrows P4 and G2 in FIG. 6 , The absolute value | Z1 | of the impedance Z1 tends to decrease as compared with the case where the metal does not exist (exists). This is because an eddy current is generated in a metal object and power is lost. Therefore, for example, it is possible to determine whether the absolute value | Z1 | of the impedance Z1 at the frequencies near the frequencies f1H and f1L described above indicates an increasing or decreasing change (the amount of change? The presence or absence of such an object can be discriminated. This makes it possible to prevent power from being unnecessarily applied to the power transmission coil L1, and also to prevent the metal from generating heat or the like.

The value of the absolute value | Z1 | of the impedance Z1 near the frequencies f1H and f1L when the secondary side device is placed in the vicinity of the primary side device depends on the magnitude of the Q value in the resonance circuit of the secondary side device Be careful. That is, the larger the Q value is, the larger the value of the absolute value | Z1 | becomes. Therefore, it can be said that the load of the secondary side device is preferably as high as possible at the time of detection operation.

Here, it is preferable that the control section 114 adjusts the change amount? Z of the absolute value of the impedance Z1 | Z1 | by controlling one or both of the frequency CTL (f) and the duty ratio CTL (D) in the control signal CTL . This is because, by setting the difference (variation DELTA Z) between | Z1 | between when there is a feed target device and when there is no feed target device as large as possible (maximum) as in the frequency near the frequencies f1H and f1L described above, .

More specifically, for example, as shown in Fig. 6A, the control unit 114 controls the frequency CTL (f) in the control signal CTL so as to be a frequency near the frequencies f1H and f1L.

7, for example, the control unit 114 sets the magnitude of the control signal CTL so that the change amount? Z of the absolute value Z1 | of the impedance Z1 becomes as large as possible, as shown in Figs. 7A and 7B. Thereby controlling the duty ratio CTL (D). This control is performed using the following phenomenon. That is, for example, as shown by reference numerals P51 and P52 in FIGS. 8A and 8B, in the case of a relatively high duty ratio CTL (D) = about 50% (in the portion (A) (Corresponding to the portion (B) in FIG. 7) between the absolute value of the impedance Z1 and the case of the relatively low duty ratio CTL (D) = about 10% There is a difference. Therefore, for example, as indicated by the arrows P5L and P5H as well as the symbols G3L and G3H in Fig. 9, the control unit 114 sets the ratio of the absolute value of the impedance Z1 to the absolute value | Z1 | of the impedance Z1 in accordance with the change in the duty ratio CTL It is preferable to adjust the amount of change? Z in consideration of the fact that the magnitude of the harmonic component changes.

If it is determined in step S106 that the secondary side device is present in the vicinity, then the power supply unit 1, for example, performs predetermined device authentication on the secondary side device (the electronic devices 2A and 2B) (Step S107). Thereafter, the power feeding unit 1 conducts the above-described non-contact type power feeding operation to charge the electronic devices 2A and 2B, which are power feeding target devices (step S108). That is, after the power feeding target device is detected, the power transmission unit 110 starts transmission to the power feeding target device. 10, the feed period Tp and the communication period Tc (a period for performing a predetermined communication operation between the primary device and the secondary device) are time-divisional And is provided periodically and periodically.

Subsequently, the power supply unit 1 judges whether or not to end the entire processing shown in Fig. 4, for example (step S109). If it is determined that the entire process has not yet been completed (step S109: NO), the power supply unit 1 determines whether a predetermined time has elapsed, for example (step S110). If it is determined that the predetermined time has not elapsed yet (step S110: No), the flow returns to step S108 to continue the power feeding operation. On the other hand, if it is determined that the predetermined time has elapsed (step S110: Yes), the flow returns to step S102 to perform the detection operation of the secondary side apparatus. Thus, it is preferable that the current-voltage detection unit 113 and the control unit 114 periodically perform the detection of the feeding target device even after the transmission is started.

If it is determined that the entire process has been completed (step S109: Yes), it is noted that the operation (entire process) in the power supply unit 1 shown in Fig. 4 is terminated.

As described above, in the present embodiment, it is detected whether or not the target device for power supply by the power transmission unit 110 exists in the vicinity by using the change of the impedance Z1 in the vicinity of the power transmission unit 110. [ As a result, it is possible to detect the feeding target device even if the configuration, technology, and the like are not complicated, for example.

As described above, in the present embodiment, it is detected whether or not the power feeding target device by the power transmitting unit 110 is present in the vicinity by using the change of the impedance Z1 in the vicinity of the power transmitting unit 110, It is possible to detect the feeding target apparatus even if the configuration, technology, and the like are not complicated. Therefore, when the transmission is performed using the magnetic field, the feeding target device can be conveniently detected. Thus, even when the coupling coefficient between the power transmission coil L1 and the power reception coil L2 is as low as 0.4 or less, it is possible to detect the power feeding target device.

In addition, since addition of a circuit such as a magnet and a magnetic sensor is unnecessary, the cost and size can be reduced, and the frequency for detection can be arbitrarily set. Therefore, the present invention can be applied to, for example, a circuit other than a self-excited oscillation circuit.

Note that the current-voltage detection unit 113 may not be provided when, for example, a circuit for detecting a current or a voltage is already provided in the power supply unit for the purpose of measuring the power consumption of the power supply unit itself Should be. In that case, additional hardware becomes unnecessary.

≪ Second Embodiment >

Next, a second embodiment of the present disclosure will be described. It should be noted that the same constituent elements as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description thereof is appropriately omitted.

[Entire Configuration of Power Supply System 4A]

Fig. 11 shows an overall block configuration example of the power supply system (power supply system 4A) according to the second embodiment. The power supply system 4A of the present embodiment is also a power supply system for performing noncontact type power transmission using a magnetic field, and includes a power supply unit 1A (primary side apparatus) and one or more electrons Device (here, two electronic devices 2A and 2B; secondary side device). That is, this power supply system 4A includes the power supply unit 1A in place of the power supply unit 1 in the power supply system 4 of the first embodiment, and in addition to the configuration of the power supply system 4 Do.

(Power supply unit 1A)

Like the power supply unit 1, the power supply unit 1A uses the magnetic field to transmit power to the electronic devices 2A and 2B. The power supply unit 1A includes a power supply unit 11A having a power supply unit 110, a power supply circuit 111, a high frequency power generation circuit 112, a current-voltage detection unit 113A, a control unit 114, ). That is, in this power transmission unit 11A, the current-voltage detection unit 113A is provided instead of the current-voltage detection unit 113 in the power transmission unit 11 described in the first embodiment. It should be noted that the current-voltage detection unit 113A and the control unit 114 correspond to the concrete example of the " detection unit " in this disclosure.

The current-voltage detection unit 113A detects the DC current (current I2) and the DC voltage (voltage V1) in the vicinity of the power transmission unit 110 instead of the alternating current (current I1) and the AC voltage V2). The current I2 and the voltage V2 correspond to the direct current and the DC voltage to be supplied from the power supply circuit 111 to the high frequency power generation circuit 112, respectively.

Next, in the control section 114 of the present embodiment, the impedance Z1 described in the first embodiment is used as the impedance in the vicinity of the power transmitting section 110 based on the direct current (current I2) and the DC voltage (voltage V2) The determined DC resistance value R2 is used. This DC resistance value R2 is determined by the following equation (4).

R2 = (V2 / I2) ... ... (4)

[Operation and Effect of Power Supply System 4A]

Specifically, for example, as in the operation example of the power supply unit 1A (power transmission unit 11A) of the present embodiment shown in Fig. 12, the control unit 114 determines whether or not the impedance Z1 The DC resistance value R2, its change amount? R and its threshold value? Rth are used instead of the absolute value | Z1 |, the change amount? R and the threshold value? Rth thereof (steps S202 to S204).

Here, based on the DC resistance value R2, the power consumed after the high-frequency power generation circuit 112 (switching amplifier) is determined. On the other hand, the increase in the impedance Z1 reduces the current flowing into the power feeding unit 110, so that the power consumption in the power feeding unit 110 is reduced, resulting in an increase in the DC resistance value R2. Thus, by judging the magnitude of the DC resistance value R2, it is possible to judge the presence or absence of the secondary side device as in the case of the impedance Z1.

At this time, if the power consumption other than the power transmitting part 110 is large, the tendency of the impedance Z1 and the tendency of the DC resistance value R2 do not coincide with each other, thereby deteriorating the detection accuracy of the secondary side device. Most of the power consumption other than the power supply unit 110 is a loss due to the coil 112L and the switching element (transistor 112T). In order to reduce the power loss caused by these, besides selecting the device with low loss, it is also possible to perform driving with a high DC voltage in order to reduce the current ratio, or to lower the driving duty ratio of the switching amplifier, Can be shortened.

As described above, also in the present embodiment, it is possible to obtain a similar effect by an action similar to that of the first embodiment. That is, when the transmission is performed using the magnetic field, it becomes possible to conveniently detect the feeding destination apparatus.

Also in this embodiment, it is not necessary to provide the current-voltage detection unit 113A in some cases, and in this case, additional hardware is unnecessary.

<Modifications>

Subsequently, modifications (modifications 1 to 6) common to the first and second embodiments will be described. It should be noted that the same constituent elements as those of the constituent elements in these embodiments are given the same reference numerals and the description thereof is appropriately omitted.

[Modifications 1 and 2]

13A is a timing chart showing the detection periods Td1 and Td2 as well as the non-detection period Ts according to Modification Example 1. FIG. 13B is a timing chart showing the detection periods Td1 and Td2 according to Modification Example 2 And a non-detection period Ts. In these Modified Examples 1 and 2, a plurality of kinds of values (here, two types; frequencies f1 and f2) are used for the frequency (CTL (f)) in the control signal CTL as described below. That is, the control unit 114 uses a plurality of kinds of values for the frequency (CTL (f)) in the control signal CTL to adjust the change amount of the impedance.

13 (a), the control unit 114 sets two kinds of values (for example, two kinds of values) in the detection period (the period corresponding to the entire detection periods Td1 and Td2) The frequencies f1 and f2 are sequentially used one by one. This makes it possible to relatively shorten the time required for detection as compared with the technique of FIG. 13 (b) described below.

On the other hand, in the variant 2 shown in Fig. 13 (b), the control unit 114 determines whether or not one of the two values (frequencies f1 and f2) is detected every detection period (every detection period Td1 and Td2) Are selectively used. This makes it possible to relatively reduce the power consumption in the detection operation as compared with the technique of Fig. 13 (a).

[Modifications 3 and 4]

14A is a timing chart showing the detection periods Td1 and Td3 as well as the non-detection period Ts according to the third variation example. FIG. 14B is a timing chart showing the detection periods Td1 and Td3 according to the fourth variation example And a non-detection period Ts. In these Modified Examples 3 and 4, a plurality of kinds of values (here, two types of duty ratios: Duty 1 and Duty 2) are used for the duty ratio CTL (D) in the control signal CTL have.

Specifically, in the modification 3 shown in FIG. 14A, the control unit 114 sets two kinds of values (duty ratio Duty1 and Duty2) within the detection period (detection periods Td1 and Td3) ) Are sequentially used one by one. This makes it possible to relatively shorten the detection time as compared with the technique of FIG. 14 (b) described below.

14 (b), the control unit 114 sets two kinds of values (the duty ratio Duty1 and the duty ratio Duty2) for each detection period (each of the detection periods Td1 and Td3) ) Are selectively used. This makes it possible to relatively reduce the power consumption in the detection operation as compared with the technique of Fig. 14 (a).

[Modifications 5 and 6]

15A is a timing chart showing the detection periods Td1 and Td4 as well as the non-detection period Ts according to the fifth variation example, and FIG. 15B is a timing chart showing only the timings Td1 and Td4 according to Modification 6 And a non-detection period Ts. In these modified examples 5 and 6, as described below, a plurality of kinds of values (in this case, two types of frequencies (in this case, two kinds of frequencies) are used for both the frequency (CTL (f)) and the duty ratio ; f1 and f2, and two kinds of duty ratios Duty1 and Duty2) are used. That is, in Modifications 5 and 6, Modifications 1 and 2 are combined with Modifications 3 and 4.

Specifically, in the modification 5 shown in Fig. 15A, the controller 114 sets two kinds of values (frequencies f1 and f2, f2 and f3) during the detection periods (detection periods Td1 and Td4) And duty ratio Duty 1 and duty ratio 2) are sequentially used one by one. This makes it possible to relatively shorten the detection time as compared with the technique of Fig. 15 (b) described below.

15 (b), the control unit 114 sets two kinds of values (frequencies f1 and f2, f1 and f2) for each detection period (each of the detection periods Td1 and Td4) And duty ratio Duty1 and Duty2). This makes it possible to relatively reduce the power consumption in the detection operation as compared with the technique of Fig. 15 (a).

<Other Modifications>

Although the technology of the present disclosure has been described using several embodiments and variations, the technology is not limited to these embodiments and modifications, and can be variously modified.

For example, although the above embodiment and the modification have been described specifically using the configuration of the high-frequency power generation circuit, the present invention is not limited thereto. For example, a configuration using a half-bridge circuit or a full-bridge circuit may be provided.

In the above-described embodiments and modifications, the configuration of the current-voltage detecting unit has been described in detail, but the present invention is not limited thereto. Other configurations and sensing operations may be used.

In the above-described embodiment and modified examples, an electronic device is described as an example of the feeding target device, but the present invention is not limited to this. (For example, a vehicle such as an electric vehicle) other than the electronic device may be used.

In the above-described embodiments and modifications, the respective components of the feed device and the feed target device (electronic device, etc.) have been described in detail. However, it is not necessary to provide all the components, and other configurations can be provided. For example, in some cases, a rechargeable battery may be provided in the power reception unit 21. [

Further, in the above-described embodiment and modified examples, a case where a plurality of (two) power feeding target devices (electronic devices) are provided in the power feeding system has been described as an example, but the present invention is not limited thereto. Only one feeding target device may be provided in the feeding system.

In addition, in the above-described embodiment and modified examples, a charging tray for a small electronic device (CE device) such as a mobile phone is described as an example of the power supply unit. However, the power supply unit is not limited to such a household charging tray, but can be applied as a charging device for various power supply target devices (electronic devices, etc.). Further, the power supply unit may not be a tray, and may be a stand for an electronic device such as a so-called cradle.

From the above-described exemplary embodiments and modifications of the disclosure, at least the following configuration can be realized.

(1) a transmission unit configured to transmit power wirelessly; And

A detecting unit operatively connected to the transmitting unit and configured to detect an object in a range from the transmitting unit based on a change in impedance near the transmitting unit,

.

(2) The power transmission device of (1), further comprising a power generation circuit operatively connected to the power transmission unit and configured to generate the power.

(3) The power transmission device of (2), wherein the power is high-frequency power.

(4)

A current-voltage detection unit configured to detect a current and a voltage in the vicinity of the transmission part; And

And a control unit operatively connected to the current-voltage detection unit and configured to detect the object based on a change in the impedance calculated by the detected current and voltage in the vicinity of the transmission unit, Device.

(5) The transmission device of (4), wherein the detected current is an alternating current and the detected voltage is AC.

(6) the detected current is a direct current and the detected voltage is DC;

Wherein the change in the impedance is a change in resistance calculated by the DC current and the DC voltage.

(7) The power transmission device of (1), wherein the detecting unit is configured to determine whether the detected object is a power feeding target device or foreign matter change by the impedance depending on whether the impedance increases or decreases.

(8) The transmission apparatus of (7), wherein the determination is made according to whether the absolute value of the impedance increases or decreases.

(9) The power transmission apparatus of (7), wherein the determination is made according to whether the resistance value increases or decreases.

(10) The transmission device according to (7), wherein the detected object is a target device to be fed by the power transmitting section when the impedance increases.

(11) The transmission device of the foreign object chain (7) when the impedance decreases.

(12) The power transmission device of (1), wherein the detection unit is configured to detect the object intermittently at intervals.

(13) The transmission apparatus of (1), wherein the detecting section is configured to detect the object by comparing a change in the impedance with a threshold value.

(14) The power transmission apparatus of (4), wherein the control section is configured to sequentially provide two control signals having the same duty ratio but different frequencies for each detection period for detecting the object.

(15) The power transmission apparatus of (4), wherein the control section sequentially provides two control signals having the same duty ratio but different frequencies for two subsequent detection periods for detecting the object.

(16) The power transmission apparatus of (4), configured to sequentially provide two control signals having the same frequency but different duty ratios for each detection period for detecting the object.

(17) The power transmission device of (4), wherein the control unit sequentially provides two control signals having the same frequency but different duty ratios for two subsequent detection periods for detecting the object.

(18) The power transmission apparatus of (4), configured to sequentially provide two control signals having different duty ratios and different frequencies during each detection period for detecting the object.

(19) The power transmission apparatus of (4), wherein the control section is configured to sequentially provide two control signals having different duty ratios and different frequencies for two subsequent detection periods for detecting the object.

(20) The power transmission device of (4), wherein the control unit controls at least one of a frequency and a duty ratio of the control signal to adjust a change of the impedance.

(21) a transmitting device; And

A transmission system comprising a receiving device,

The transmitting apparatus includes:

(a) a transmission section configured to transmit power wirelessly, and

(b) a detecting section operatively connected to the transmitting section and configured to detect a receiving apparatus within a range from the transmitting section based on a change in impedance near the transmitting section,

The receiving apparatus includes:

(c) a power receiving unit configured to receive the power wirelessly, and

and (d) a load operatively connected to the power receiving unit and configured to perform an operation based on the received power.

(22) The transmission system of (21), wherein the transmitting apparatus further comprises a power generation circuit operatively connected to the power transmission unit and configured to generate the power.

(23)

A current-voltage detection unit configured to detect a current and a voltage in the vicinity of the transmission part; And

And a control unit (22) operatively connected to the current-voltage detection unit and configured to detect the object based on a change in the impedance calculated by the detected current and voltage near the transmission unit system.

(24) detecting a current and a voltage in the vicinity of the power transmission apparatus;

Calculating an impedance based on the detected current and voltage; And

And detecting an object within a range from the power transmission apparatus based on a change in impedance.

(25) The object detection method according to (24), further comprising the step of determining whether the detected object is a power reception target receiving apparatus or foreign matter change by the power transmission apparatus, depending on whether the impedance increases or decreases.

(26) The object detection method of (25), wherein the determination is made according to whether the absolute value of the impedance increases or decreases.

(27) The object detection method of (25), wherein the determination is made according to whether the resistance value increases or decreases.

(28) When the impedance is increased, the detected object is a water receiving device.

(29) When the impedance decreases, the detected object is the object of the foreign object chain.

(30) The method of detecting object according to (24), further comprising comparing the change in impedance with a threshold value.

(24) wherein the object is intermittently detected at intervals of a predetermined interval (31).

(32) The object detecting method according to (25), further comprising the step of wirelessly transmitting power from the power transmission apparatus to the power receiving apparatus in response to determination that the detected object is a water receiving apparatus.

This application is related to the disclosure of Japanese Patent Application JP 2011-197865 filed on September 12, 2011, the entire contents of which are incorporated herein by reference.

It should be understood by those skilled in the art that various changes, combinations, subcombinations, and variations may be made depending on design requirements and other factors, provided that various modifications, combinations, subcombinations, and variations are within the scope of the appended claims or their equivalents do.

Claims (17)

As a transmitter,
A transmitter including a coil and configured to transmit power wirelessly;
A resistor in series with the coil; And
A detection unit configured to measure a voltage applied to the coil and to detect a foreign object within a range from the power supply unit based on the voltage;
And a transmission device. The method according to claim 1,
Wherein the detecting unit is configured to detect the object intermittently at intervals. The method according to claim 1,
Wherein the transmission unit is configured to transmit the power and the second frequency of the voltage that the detection unit is configured to detect the object are different from each other. The method according to claim 1,
Wherein the detector is further configured to compare the voltage to a threshold and to detect the object based on the comparison result. The method according to claim 1,
Wherein the detecting section is further configured to calculate an impedance in the vicinity of the transmitting section based on the voltage and to detect the object based on the impedance. 6. The method of claim 5,
Wherein the detector is further configured to compare the impedance to a threshold and to detect the object based on the comparison result. The method according to claim 1,
Wherein the power transmission unit further comprises a capacitor electrically connected in parallel or in series and parallel combination to the coil. The method according to claim 1,
Wherein the detecting section is further configured to detect the object based on a change in the load impedance of the power generating circuit. 9. The power transmitter according to claim 8, further comprising a power generation circuit operatively connected to the power transmission unit and configured to generate the power. 9. The method of claim 8,
A current-voltage detection unit configured to detect a current and a voltage in the vicinity of the transmission part; And
A control unit operatively connected to the current-voltage detection unit and configured to detect the object based on the detected current and a change in the load impedance calculated by the detected voltage;
And a transmission device. 9. The method of claim 8,
Wherein the detecting section is further configured to detect a device fed by the transmitting section based on the voltage. In the transmission,
Transmitting power wirelessly through a coil;
Measuring a voltage across the coil; And
Detecting the object within the range from the transmission based on the voltage
/ RTI &gt; 13. The method of claim 12,
Wherein the object is intermittently detected at intervals. 13. The method of claim 12,
Wherein the first frequency of the voltage to which the power is transmitted and the second frequency of the voltage at which the object is detected are different from each other. 13. The method of claim 12, further comprising detecting the object based on a change in load impedance of the power generation circuit. 13. The method of claim 12,
And detecting the powered device based on the voltage. As a feed system,
Including electricity transmission and water delivery,
The transmission /
A transmitter including a coil and configured to transmit power wirelessly;
A resistor in series with the coil; And
A detecting unit configured to measure a voltage applied to the coil and to detect the object within a range from the power transmitting unit based on the voltage;
Lt; / RTI &gt;
The water-
A receiver configured to receive power wirelessly; And
A load operatively connected to the power receiver and configured to perform an operation based on the received power;
.

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