JP2002010535A - Non-contact power transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-contact power transmission device capable of stabilizing output terminal voltage to a constant value in a wide load range. SOLUTION: This non-contact power transmission device consists of a non- contact receptacle 1 including, a power circuit 10 outputting a DC voltage E and an inverter circuit 11 generating a const frequency high-frequency voltage V1 by inputting the DC voltage E and switching a semiconductor switch and a primary coil L1 for power transmission to which is supplied the high-frequency voltage V1 from the inverter circuit 11, a non-contact plug 2 including a secondary coil L2 for receiving power in which a high-frequency voltage V2 is induced by the primary coil L1 for power transmission and a rectifying and smoothing circuit 20 rectifying and smoothing the high frequency voltage V2 induced in the secondary coil L2 for receiving power, and a terminal apparatus 3 connected to the output terminal of the non-contact plug 2 to server as a load, and conducts thinning-out control for thinning out the high-frequency voltage V1 of constant frequency supplied to the primary coil L1 for power transmission from the inverter circuit 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contact power transmission device.

[0002]

2. Description of the Related Art In recent years, practical use of non-contact power transmission using electromagnetic induction has been actively performed. Most of these have specified loads, and there is no practical example in which a plurality of loads are targeted, or the load current of a single load greatly changes. In non-contact power transmission, there is an electrical insulator between the primary side, which is the power supply side, and the secondary side having the load, and the primary coil on the power supply side and the secondary coil on the load side.
Power is transmitted through a transformer having a structure that can be separated and attached to the secondary coil. FIG. 27 shows a schematic configuration diagram of a first conventional example of a non-contact power transmission device using the transformer. The primary side is configured such that a high frequency voltage V1 of about 20 KHz or more, which is equal to or higher than an audible frequency generated by an inverter circuit (omitted in the conventional example), is applied to both ends of a primary coil L1 on the power supply side. The secondary side includes a secondary coil L2 on the load side having a degree of magnetic coupling M between the primary coil L1 and a secondary coil L2.
It comprises a smoothing rectifier circuit 20 for rectifying the voltage induced in the secondary coil L2, and a load 3a, which is a load connected to the output terminal of the smoothing rectifier circuit 20, and includes primary coils L1 and L2.
A power transmitting / receiving transformer T1 having a structure that can be separated and attached to the secondary coil L2 is configured. FIG. 28 shows the structure of the power transmitting / receiving transformer T1. The primary side for supplying electric power has a primary side coil L1 provided on an E-shaped core A4 made of a magnetic material, and the secondary side supplied with electric power from the primary side also has an E-shaped coil made of a magnetic material. 2 provided on the mold core A4
GAP 116 having a secondary coil L2 and electrically isolated from each other
Are installed facing each other. In such a detachable power transmitting and receiving transformer T1, a leakage magnetic flux F1 is generated, and the degree of magnetic coupling M between the primary coil L1 and the secondary coil L2 is reduced. Here, FIG. 29 shows the circuit of FIG.
The equivalent circuit converted to the secondary side is shown. The leakage inductance L4 is connected in series to the output of the voltage source E2 having the induced voltage of the secondary coil L2, and is connected to the load 3a via the smoothing rectifier circuit 20. As described above, the secondary coil L2 of the total magnetic flux generated in the primary coil L1 due to the decrease in the degree of magnetic coupling M
Decreases, the leakage inductance L4 due to the leakage magnetic flux F1 occurs. Also, the primary coil L
1 is driven at a high frequency of about 20 KHz or higher, which is higher than the audible frequency, so that the magnetic coupling degree M is low and the power is supplied to the load 3a via the power transmitting / receiving transformer T1 having the leakage inductance L4. Is transmitted, the induced voltage of the secondary coil L2, that is, the voltage of the voltage source E2 decreases, causing a voltage drop due to the inductive reactance due to the leakage inductance L4, and as a result, the output terminal voltage V3 decreases. FIG. 30 shows the load current I3 shown in FIG.
FIG. 11 is a diagram showing a characteristic 117a of an output terminal voltage V3 and a characteristic 118a of a load power P with respect to FIG. Output terminal voltage V3
Decreases linearly due to the AC impedance due to the leakage inductance L4. When the load current I3 is equal to or lower than a predetermined voltage, the load power P increases as the load current I3 increases. However, when the load current I3 is equal to or higher than the predetermined voltage, the load power P increases as the load current I3 increases. The load power P decreases. In the case of having such characteristics, when a device having a different load current that operates with a constant voltage input is provided as the load 3a, as the load current I3 increases above a predetermined current value, the output terminal voltage V3 decreases. ,
The constant voltage input condition of the load 7 is deviated, and the original performance cannot be exhibited.

In the case of non-contact charging in non-contact power transmission, a capacitor is connected in parallel or in series to the secondary coil L2 to improve the power factor by load matching, thereby compensating for the influence of the leakage inductance L4 and compensating for the secondary. In many cases, the effective power that can be extracted by the side is increased. The circuit diagram of FIG. 31 is obtained by connecting a capacitor C2 in parallel to the secondary coil L2 of FIG. 27. FIG. 32 shows an equivalent circuit obtained by converting the circuit of FIG. The leakage inductance L4 is connected in series to the output of the voltage source E2 having an induced voltage of, and the capacitor C2 is connected in parallel to the voltage source E2 via the leakage inductance L4. Connected to load 3a. By connecting the capacitor C2, the power transmission efficiency is greatly improved and the size can be reduced. Load 3
When charging a, the output terminal voltage V3 becomes, for example, a battery voltage and is substantially constant. However, when the load 3a is not a constant voltage load, for example, a load such as a resistor, FIG.
3 is a characteristic 11 of the output terminal voltage V3 with respect to the load current I3.
7b and the characteristic 118b of the load power P, when the load current I3 increases as compared with the case where the capacitor C2 is not connected, the output terminal voltage V
3 is remarkably observed. Further, when the output terminal voltage V3 is near the point K where the load power P peaks, the optimum load matching is performed. In a region where the load current I3 is larger than the load current at the point K, the output terminal voltage V3 rapidly decreases. I do. Even in a region where the load current I3 is smaller than the load current at the point K, the output terminal voltage V3 decreases in inverse proportion to the load current I3. In a region where the load current I3 is extremely small, the output terminal voltage V3 suddenly increases.

In the non-contact power transmission having the above-described characteristics and characteristics, as shown in the characteristic 117c of the output terminal voltage V3 with respect to the load current I3 and the characteristic 118c of the load power P in FIG. It is desired to provide a method of stabilizing the output terminal voltage V3 at a constant level in all load regions for loads having different currents I3. In order to obtain this stable characteristic, the output terminal voltage V3 on the secondary side is detected, compared with a reference voltage, error-amplified, and error-amplified on the primary side, as performed by ordinary voltage control of a switching power supply. Is transmitted in a non-contact manner to drive the primary side drive voltage amplitude,
Examination of a feedback control method for controlling the frequency, the duty, and the thinning rate has revealed that any of the conventional techniques causes inconvenience.

[0005]

In the non-contact transmission, compared to a normal switching power supply, noise due to the leakage magnetic flux F1 is slightly increased, and the circuit efficiency is slightly reduced even if load matching is performed. The inverter circuit for generating the high-frequency voltage V1 applied to the next coil L1 optimally employs a resonance type inverter. Then, in the voltage region to be stabilized, optimal load matching is performed at the time of the target maximum load current, that is, the capacitance of the capacitor C2 connected to the secondary side is set to an optimal value for performing load matching. It is best to set.

However, in the above-described circuit system, there is an inconvenience when stabilizing the output terminal voltage V3 to be constant from no load to full load. Since the load matching capacitor C2 connected to the secondary side is connected in all load current regions, the inverter circuit for generating the high-frequency voltage V1 applied to the primary coil L1 has P
In the WM method and the frequency variable method, if the change width of the frequency or the duty ratio is large, the circuit operation may be unstable. As shown in the secondary side equivalent circuit shown in FIG.
Since a series resonance circuit in which a leakage inductance L4 and a capacitor C2 are connected in series is connected to the voltage source E2 having an induced voltage of the secondary coil L2, the high frequency voltage V1 applied to the primary coil L1 is It is considered that when the frequency and the duty ratio change greatly and the frequency and the duty ratio of the voltage induced in the secondary coil L2 change greatly, the operation of the series resonance circuit also changes greatly. Even if this effect can be ignored, the load current I
When 3 has to be changed very large (for example, when there is a change width of 100 times), the frequency and duty ratio of the high-frequency voltage V1 applied to the primary coil L1 must also be changed very large. Especially for light loads,
In some cases, control near no load exceeds the practical limit of circuit operation and becomes impossible to control.

When the inverter circuit for generating the high-frequency voltage V1 applied to the primary coil L1 performs the conventional thinning control, the conventional thinning control is performed as follows. A control method for stopping the inverter when the detected voltage of the output terminal voltage exceeds the target voltage to be stabilized while continuously driving the high-frequency voltage V1 at a fixed frequency. This method is also used near light load and no load. In the vicinity of the target voltage, on / off operations less than one cycle of the drive frequency are frequently performed, and low-loss soft switching, which is a merit of the resonant inverter, is not performed, and hard switching is performed to increase switching loss. As well as a strong noise source.

In these control systems, in the prior art, information such as the output terminal voltage V3 on the secondary side is transmitted via a photocoupler using an optical signal to the drive voltage amplitude, frequency, and frequency of the inverter circuit on the primary side. This is feedback control for controlling the duty ratio and the thinning rate. However, non-contact power transmission equipment has advantages when used in bad environments such as bathrooms and outdoors near water or in places with lots of dirt, so it uses optical signals that are affected by the surrounding brightness and dirt. It is difficult to adopt technical means.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a non-contact power transmission device capable of stabilizing an output terminal voltage at a constant value over a wide load range.

[0010]

According to a first aspect of the present invention, there is provided a power supply circuit for outputting a DC voltage, an inverter circuit for converting the DC voltage into a high frequency voltage having a constant frequency, and the high frequency voltage being supplied from the inverter circuit. A non-contact outlet composed of a primary coil for power transmission, a secondary coil for power reception in which a high-frequency voltage is induced by forming a transformer structure detachable from the primary coil for power transmission and the power reception A non-contact plug composed of a rectifying / smoothing circuit for rectifying / smoothing a high-frequency voltage induced in the secondary coil for
In a non-contact power transmission device including a terminal device connected to an output terminal of the non-contact plug and serving as a load, the non-contact outlet includes an output terminal voltage of the non-contact plug with respect to a target load region, A control means for performing thinning control for thinning out and stabilizing a high-frequency voltage supplied to the power transmission primary coil from an inverter circuit is provided, and the output terminal voltage can be stabilized at a constant value over a wide load range. A contact power transmission device can be provided.

According to a second aspect of the present invention, in the first aspect of the present invention, when the output terminal voltage of the non-contact plug exceeds a predetermined voltage, the control means transmits the power from the inverter circuit to the primary coil for power transmission. The supply of the high-frequency voltage is thinned out for a certain period of time, and if the output terminal voltage of the non-contact plug is higher than the predetermined voltage after the thinning out for the certain time, the supply of the high-frequency voltage to the power transmission primary coil is performed again. If the output terminal voltage of the non-contact plug falls below a predetermined voltage after performing the above-described decimation for a certain period of time, the power is output until the output terminal voltage of the non-contact plug exceeds the predetermined voltage. Characterized by continuing the operation of continuously supplying the high-frequency voltage to the power transmission primary coil,
It is possible to provide a non-contact power transmission device capable of stabilizing an output terminal voltage at a constant value over a wide load range.

According to a third aspect of the present invention, in the first or second aspect, the non-contact plug converts information representing an electric state inside the non-contact plug into a magnetic signal, transmits the magnetic signal to the non-contact outlet, and controls the control. The means forms a control signal for thinning control based on the magnetic signal, and controls the thinning of the inverter circuit by the control signal.To use the magnetic signal as a feedback signal for voltage stabilization, It is possible to provide a non-contact power transmission device capable of stabilizing an output terminal voltage at a constant value over a wide load range without being affected by surrounding brightness or dirt.

According to a fourth aspect of the present invention, in any one of the first to third aspects of the present invention, the inverter circuit is a half-bridge type partial resonance inverter, which suppresses an increase in output voltage at the time of failure. it can.

According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the power receiving secondary coil has a center tap, and the rectifying and smoothing circuit is connected in series to both output terminals which are not center taps of the power receiving secondary coil. And a full-wave rectifying unit that connects the other ends of the rectifiers that are not connected to the power receiving secondary coils of the rectifiers connected in opposite directions to each other, and connects a choke coil to a connection midpoint of the rectifiers. The feature is that the rectifier can be downsized.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects of the present invention, a capacitor is connected in parallel to the power receiving secondary coil. The active power that can be transmitted to the next side can be increased.

According to a seventh aspect of the present invention, in the sixth aspect of the present invention, the capacitance value of the capacitor is the maximum value of the high-frequency voltage supplied to the power transmission primary coil at the time of the maximum load in the target load region. It is characterized in that the polarity reversal time is the capacitance value at which the oscillation voltage generated at both ends of the capacitor becomes the maximum value or the minimum value, and the optimum load matching is performed to improve the circuit efficiency. be able to.

According to an eighth aspect of the present invention, in any one of the third to seventh aspects, the non-contact outlet is provided with a primary signal receiving coil, and the non-contact plug is disposed to face the primary signal receiving coil. A secondary signal transmitting coil which forms a transformer structure detachable from the primary signal receiving coil is provided, and the secondary signal transmitting coil converts information representing an electrical state inside the non-contact plug into an AC voltage. Is input, generates a magnetic flux signal as a magnetic signal, the primary side signal receiving coil is induced voltage by the magnetic flux signal,
The control means performs the thinning-out control on the inverter circuit by a control signal based on the induced voltage, and uses a magnetic flux signal as a feedback signal for voltage stabilization. It is possible to provide a non-contact power transmission device capable of stabilizing an output terminal voltage to a constant value over a wide load range without receiving the power.

A ninth aspect of the present invention is the invention according to the eighth aspect of the present invention, wherein the power transmitting primary coil and the primary signal receiving coil and the power receiving secondary coil and the secondary signal transmitting coil are connected to each other. A magnetic shield partition made of a magnetic material is provided between at least one of the gaps to reduce the magnetic flux generated by the current transmission / reception transformer linked to the signal transmission / reception transformer, thereby achieving accurate voltage stabilization. Can be transmitted and received.

According to a tenth aspect of the present invention, in the ninth aspect of the present invention, the primary coil for power transmission and the secondary coil for power reception are wound around a core made of a magnetic material, and the cores are connected to each other by the core of the core. It is characterized by being axially opposed to each other, reducing the magnetic flux generated by the current transmitting / receiving transformer interlinking with the signal transmitting / receiving transformer, enabling transmission and reception of magnetic flux signals for accurate voltage stabilization. .

According to an eleventh aspect of the present invention, in the ninth aspect of the present invention, the primary coil for power transmission and the secondary coil for power reception are provided with a bottomed cylinder having an opening in a direction perpendicular to the axial direction of the coil. Wound around a core made of a magnetic material of a mold, and the cores are arranged to face each other in the axial direction of the core. The arrangement is characterized in that the magnetic flux generated in the current transmitting / receiving transformer linked to the signal transmitting / receiving transformer is reduced, and the magnetic flux signal for accurate voltage stabilization can be transmitted / received.

According to a twelfth aspect of the present invention, in any one of the eighth to eleventh aspects, the secondary-side signal transmitting coil receives a signal obtained by converting information representing an electric state inside the non-contact plug into an AC voltage. Thus, a magnetic flux signal having a phase opposite to that of the magnetic flux generated by the power transmission primary coil is generated, and a flux signal for accurate voltage stabilization can be transmitted and received.

According to a thirteenth aspect, in the twelfth aspect, one terminal of the secondary-side signal transmitting coil is connected to one of the terminals of the power receiving secondary coil. As a result, a magnetic flux signal for accurate voltage stabilization can be transmitted and received.

According to a fourteenth aspect of the present invention, in any one of the third to seventh aspects of the present invention, the non-contact outlet includes a power transmitting primary coil and a power receiving secondary coil near the power transmitting primary coil. A magnetic flux detection coil for detecting a magnetic flux generated therebetween, wherein the magnetic flux detection coil detects a magnetic flux generated in the power transmission primary coil as a magnetic signal, and converts the magnetic flux to the detected magnetic flux from the magnetic flux detection coil. The control means performs thinning control of the inverter circuit based on the voltage output in response thereto, and can receive a magnetic flux signal for accurate voltage stabilization.

According to a fifteenth aspect, in the fourteenth aspect, the primary coil for power transmission and the secondary coil for power reception are each provided with a bottomed cylinder having an opening in a direction perpendicular to the axial direction of the coil. And a magnetic flux detecting coil disposed near an opening of the core of the power transmission primary coil. The magnetic flux detecting coil is disposed near the core of the primary coil for power transmission. Then, a magnetic flux signal for accurate voltage stabilization can be received.

According to a sixteenth aspect of the present invention, in any one of the first to fifteenth aspects, one non-contact outlet is adapted to a plurality of non-contact plugs having different output voltages, and each non-contact plug is a target load. It is economical to have the control means for keeping the output voltage of each of the non-contact plugs within a predetermined voltage range in the entire region including the region.

The invention of claim 17 is characterized in that, in any one of the inventions of claims 1 to 16, a resistor is connected in parallel to the output terminal of the non-contact plug, and the output terminal voltage is kept constant over a wide load range. It is possible to provide a non-contact power transmission device that can be stabilized.

The invention according to claim 18 is the invention according to any one of claims 1 to 17, wherein when the non-contact plug is not connected to a predetermined position of the non-contact outlet, the control means transmits power from the inverter circuit. It is characterized by limiting the output supplied to the primary coil for use, and can provide high safety and reliability.

According to a nineteenth aspect of the present invention, in the invention of the eighteenth aspect, the non-contact outlet has a switch function for controlling the restriction of the supply of the high-frequency voltage from the inverter circuit to the power transmission primary coil. A driver for controlling the on / off state of the switch function, and when the non-contact plug is connected to a predetermined position of the non-contact outlet, the switch function is operated so that the control means can control the primary power transmission from the inverter circuit. It is characterized in that high-frequency voltage can be supplied to the coil, and high safety and reliability can be provided.

According to a twentieth aspect of the present invention, in the nineteenth aspect, the switch function of the non-contact outlet comprises a mechanical contact, a driving body provided in the non-contact plug comprises a magnet, and the non-contact plug is a non-contact outlet. When coupled to a predetermined position, the mechanical contact operates by the magnetic force of the magnet, and the control means enables supply of a high-frequency voltage from the inverter circuit to the primary coil for power transmission, thereby providing high safety. And reliability.

According to a twenty-first aspect of the present invention, in any one of the first to twentieth aspects, when the non-contact plug is connected to a predetermined position of the non-contact outlet, it is used for at least one of the non-contact plug and the non-contact outlet. It is characterized in that a display for notifying the possibility is performed, and it is possible to determine whether the system or the device can be used.

According to a twenty-second aspect of the present invention, in any one of the first to twenty-first aspects, at least one of the non-contact outlet and the non-contact plug is connected to an output terminal of the non-contact plug. And a display unit for displaying at least one of the output voltage of the non-contact plug is added, so that it is possible to determine whether the system or the device can be used.

According to a twenty-third aspect of the present invention, in any one of the first to twenty-second aspects, a terminal device connected to an output terminal of the non-contact plug is detachably attachable to and detachable from the non-contact plug. , Unspecified terminal equipment can be used.

According to a twenty-fourth aspect of the present invention, in the twenty-third aspect, the power supply from the output terminal of the non-contact plug to the terminal device is supplied by magnetic coupling. Can be used.

According to a twenty-fifth aspect of the present invention, in any one of the first to twenty-fourth aspects, between the output terminals of the non-contact plug,
It is characterized by connecting a voltage clamp element, and can provide high safety and reliability.

[0035]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a circuit configuration of a contactless power transmission device that performs thinning control using a magnetic signal. The non-contact power transmission device 5 includes a non-contact outlet 1 constituting a primary side serving as a power supply side and a non-contact plug 2 constituting a secondary side having a load. A power supply circuit 10 for converting an AC input from the DC power supply into a DC voltage for outputting a DC voltage E, and a semiconductor switch. The DC voltage E from the power supply circuit 10 is turned into a high-frequency voltage V1 having a constant frequency by switching the semiconductor switch. The switching of the semiconductor switch of the inverter circuit 11 according to the inverter circuit 11 for conversion, the primary coil L1 for power transmission supplied with the high frequency voltage V1 from the inverter circuit 11, and the magnetic signal fed back from the non-contact plug 2. And a switching control circuit 12 that outputs a control signal to be controlled. Among the leakage flux F1 and flux linkage F2 generated by applying high frequency voltage to the primary coil L1, the interlinkage magnetic flux F
2, a power receiving secondary coil L2 in which a high frequency voltage is induced by interlinking with 2, a rectifying / smoothing circuit 20 for rectifying and smoothing a high frequency voltage output from the power receiving secondary coil L2,
An output terminal voltage detection circuit 21 for detecting an output terminal voltage V3 which is an output voltage of the non-contact plug 2, and outputting a magnetic signal to the switching control circuit 12 of the non-contact outlet 1 according to the detection result; The voltage V3 is output to the terminal device 3, which is a load. Primary coil L for power transmission
1 and the power receiving secondary coil L2 constitute a power transmitting and receiving transformer T1 that can be separated and attached.

In the present embodiment, the output terminal voltage detection circuit 21 which has detected the output terminal voltage V3 generates a magnetic signal according to the detection result, and the switching control circuit 12 which has received the magnetic signal generates a magnetic signal based on the magnetic signal. When the output terminal voltage V3 exceeds a predetermined voltage, the supply of the high-frequency voltage V1 having a constant frequency from the inverter circuit 11 to the power transmission primary coil L1 is thinned out for a certain period of time, and after a certain period of time. If the output terminal voltage V3 is still higher than the predetermined voltage, the supply of the high-frequency voltage V1 to the power transmission primary coil L1 is repeated for a certain period of time again. Is lower than the predetermined voltage, the high-frequency voltage V1 applied to the power transmission primary coil L1 until the output terminal voltage V3 exceeds the predetermined voltage.
A control signal for performing thinning control for continuing the operation of supplying the power to the inverter circuit 11 is output to the inverter circuit 11.
Performs a switching operation in response to the control signal to stabilize the output terminal voltage V3 to a constant voltage.

FIG. 2 shows a specific circuit configuration of this embodiment. 2, a power supply circuit 10 is represented by a DC voltage source 10a that outputs a DC voltage E, and an output terminal voltage detection circuit 21
The switching control circuit 12 is omitted. The non-contact outlet 1 includes a DC voltage source 10a, a series circuit of capacitors C3 and C4 and a series circuit of semiconductor switches Q1 and Q2 connected in parallel to the DC voltage source 10a, and a capacitor C
1 and the capacitor C2 and the semiconductor switch Q1
Circuit 11 comprising a capacitor C1 connected between the capacitor C1 and a midpoint of connection with the semiconductor switch Q2, and a power transmission primary coil L connected in parallel with the capacitor C1.
1 to form a half-bridge type partial resonance inverter circuit. The non-contact plug 2 includes a power receiving secondary coil L2 having a center tap, a capacitor C2 connected in parallel to the power receiving secondary coil L2, and both outputs that are not center taps of the power receiving secondary coil L2. Diodes D3, D connected in series and opposite to each other at the ends
4. A rectifier composed of a choke coil L3 having one end connected to a connection midpoint between the diodes D3 and D4, and a smoothing capacitor C5 connected between the other end of the choke coil L3 and the center tap of the power receiving secondary coil L2. The terminal device 3 includes a smoothing circuit 20 and is connected to the smoothing capacitor C5 in parallel. The power transmission primary coil L1 and the power reception secondary coil L2 constitute a power transmission / reception transformer T1 that can be separated and attached. The power receiving secondary coil L2 is provided with a center tap and is rectified by the two diodes D3 and D4, so that the size of the device can be reduced.

Next, FIG. 3 shows the voltage V1 across the power transmission primary coil L1 and the power transmission primary coil L1 in FIG.
1, a voltage V4a across the semiconductor switch Q1, a current I4a flowing through the semiconductor switch Q1,
5 shows respective waveforms of a voltage V4b across the semiconductor switch Q2 and a current I4b flowing through the semiconductor switch Q2. The semiconductor switches Q1 and Q2 are alternately turned on and off alternately. At this time, after one semiconductor switch is turned off from on, a certain period of time when both semiconductor switches are turned off, and then the other semiconductor switch is turned on. Control,
The voltage V1 across the primary coil L1 for power transmission has a trapezoidal waveform. The partial resonance section 100 is a semiconductor switch Q
1 and Q2 are both turned off, and the power transmission 1
This is a period during which voltage oscillation due to the resonance operation between the inductance viewed from the secondary coil L1 and the secondary side and the capacitor C1 is performed. When a MOSFET is used for the semiconductor switch, the parasitic diodes D1 and D2 are connected in parallel to the semiconductor switches Q1 and Q2 as shown in FIG.
The oscillation voltage of the voltage V1 across the secondary coil L1 increases,
When the voltage is clamped at the voltage E / 2 or the voltage E / 2, the voltage V4a across the semiconductor switch Q1 and the voltage of the semiconductor switch Q
2 is a trapezoidal wave clamped to the voltage E of the DC power supply 10a or the ground level. When MOSFETs are used for the semiconductor switches Q1 and Q2, a partial resonance operation can be performed even by utilizing the parasitic capacitance of the MOSFETs. Due to this partial resonance, the semiconductor switches Q1, Q
2 can perform soft switching, and can greatly reduce the loss at the time of turn-on and turn-off.

FIG. 4 shows the output terminal voltage V3 and the voltage V1 across the primary coil L1 for power transmission when the thinning control of the prior art is performed in the vicinity of no load and light load. In the conventional thinning control, the output terminal voltage V3 is detected, the fixed frequency driving of the inverter circuit 11 is stopped only when the detection result exceeds the target voltage 101, and the output of the fixed frequency high frequency voltage V1 is stopped. . In such control, as shown in FIG. 4, near light load and no load, the semiconductor switches Q1 and Q2 that are less than one cycle of the drive frequency near the target voltage 101 are frequently turned on and off. As described in the above-mentioned prior art, the resonance type inverter does not perform low-loss soft switching, which is an advantage of the resonance type inverter, and performs hard switching and becomes a strong noise source. In particular, in wireless power transfer,
This tendency is apt to appear remarkably because noise is apt to be applied to the output terminal due to the influence of the magnetic field due to the leakage magnetic flux and the spread of the magnetic flux.

FIG. 5 shows the conventional thinning control.
In addition, when the load state is near no load and light load, the two target voltages 102 and 10 are set as the target voltages of the output terminal voltage V3.
3, the fixed frequency driving of the inverter circuit 11 is stopped when the output terminal voltage V3 exceeds the target voltage 102, and the fixed frequency driving of the inverter circuit 11 is stopped when the output terminal voltage V3 becomes lower than the target voltage 103. The output terminal voltage V3 at the time and the voltage V1 across the primary coil L1 for power transmission are shown. By forming a hysteresis using the two target voltages 102 and 103, the operation and the stop of the fixed frequency driving of the inverter circuit 11 are performed more favorably than the conventional method shown in FIG. Practically, this method can be used, but when noise is superimposed greatly, the hysteresis width must be increased, and the output terminal voltage V3
Causes an increase in ripple voltage.

Therefore, in the present invention, as shown in FIG. 6, when the output terminal voltage V3 exceeds the target voltage 108, the supply of the high frequency voltage V1 of a constant frequency from the inverter circuit 11 to the primary coil L1 for power transmission is performed. The output terminal voltage V after thinning out the fixed time 106 and thinning out the fixed time 106
3 is still higher than the target voltage 108, the supply of the high-frequency voltage V1 to the primary coil L1 for power transmission is repeatedly thinned out for a certain period of time 106. After the thinning-out of each fixed time 106, the output terminal voltage V3 Is lower than the target voltage 108, the high-frequency voltage V applied to the power transmission primary coil L1 until the output terminal voltage V3 exceeds the target voltage 108.
The thinning control for continuing the operation of supplying 1 is performed, and the series of operations is continued to stabilize the output terminal voltage V3. In this method, in the range from light load to full load, at the end of the idle period of the fixed time 106, the output terminal voltage V3 surely falls below the target voltage 108 to a certain extent, and the fixed frequency drive of the inverter circuit 11 is also continuously performed.
More than a cycle can be secured. In the case of a complete no-load operation, the fixed frequency driving of the inverter circuit 11 may be shorter than one cycle. Even in this case, the period of the fixed frequency driving operation and the period of the stop of the inverter circuit 11 are constant. Is repeated regularly in the cycle of
The harmonic noise can be reduced as compared with the case of FIG. 4 in which the fixed frequency driving period and the stop period are irregularly repeated. Further, another advantage of this embodiment is that the output terminal voltage V
3, the maximum voltage 107 can be made almost the same. Therefore, in particular, when stabilizing a low voltage used around water in a bathroom or the like, the target voltage 108 is set to a voltage lower than the upper limit of the voltage standard by a small margin. If set, the output terminal voltage V3 can be reliably controlled within the upper limit value of the voltage standard.
It is possible to stabilize the output terminal voltage V3 in consideration of safety and security.

Next, FIG. 7 shows waveforms of the voltage V1 across the primary coil L1 for power transmission, the voltage V2 across the capacitor C2, the current I2 flowing through the capacitor C2, and the load current I3 flowing through the terminal equipment 3. Is shown. The condition under which the capacitor C2 can be connected in parallel to the power receiving secondary coil L2 to perform optimum load matching is as shown in the timing 109 in FIG. 7 as the polarity of the voltage V1 across the power transmitting primary coil L1. The time of inversion coincides with the time when the oscillating voltage of the voltage V2 across the capacitor C2 reaches the maximum value, and the voltage V across the power transmission primary coil L1 as shown at a timing 110.
This is equivalent to the time when the polarity of 1 is inverted and the time when the oscillation voltage of the voltage V2 across the capacitor C2 reaches the minimum value. As shown in FIG. 7, the capacitance value of the capacitor C2 for performing optimum load matching depends on the driving frequency of the inverter circuit 11, the leakage inductance L4 between the power transmission primary coil L1 and the power reception secondary coil L2. In addition, it is affected by the output terminal voltage V3 and the rectifying method of the rectifying / smoothing circuit 20.

FIGS. 8 and 9 show the load current I3 in this embodiment.
6 shows the characteristics 117d and 117e of the output terminal voltage V3 with respect to. A region 111 where the load current I3 is smaller than the point K where the maximum load power can be obtained, that is, the point K where the load matching is optimally obtained.
In 113 and 113, the output terminal voltage V3 is higher than the output terminal voltage V3 at the point K. Therefore, the output terminal voltage V3 can be stabilized by the voltage reduction operation by the thinning control in the present embodiment. On the other hand, in the regions 112 and 114 where the load current I3 exceeds the point K, the output terminal voltage V3 rapidly drops and cannot be used. By performing the optimum load matching with the capacitor C2 in this manner, the non-contact power transmission device 5 of the present invention can be operated in the most efficient state. Further, when the load exceeds the applicable load range, for example, even if an internal short circuit occurs due to a failure of the terminal device 3, the point K
When the load current I3 becomes larger than the above, the voltage drop of the output terminal voltage V3 occurs sharply, and the output terminal voltage V3 becomes low, and the load current I3 is current-limited so that the system is safe and secure. ing.

FIGS. 10 to 23 show specific examples of the embodiment of the present invention. The basic structure is almost the same as that of FIGS. 1 and 2, and the same components are denoted by the same reference characters and will not be described. Omitted. In FIG. 10, a non-contact outlet 1 constituting a primary side serving as a power supply side includes an inverter circuit 11 which receives a DC power supply and outputs a high-frequency voltage having a constant frequency (in FIGS. 10 to 16, outputs a DC power supply). The power supply circuit is omitted), the power transmission primary coil L1 supplied with the high frequency voltage from the inverter circuit 11, and the non-contact plug 2
Primary-side signal receiving coil 14 whose voltage is induced by a magnetic signal fed back from secondary-side signal transmitting coil 23
A signal conversion circuit 13 for outputting a signal based on the induced voltage, and a switching control circuit 12 for outputting a control signal for thinning out switching of a semiconductor switch of the inverter circuit 11 in accordance with an output signal of the signal conversion circuit 13
The non-contact plug 2 constituting the secondary side having the load is linked with the magnetic flux F3 generated by the high-frequency voltage applied to the power transmission primary coil L1 to induce the high-frequency voltage. Power receiving secondary coil L2, rectifying / smoothing circuit 20 for rectifying and smoothing the high frequency output of power receiving secondary coil L2, and output terminal voltage for detecting output terminal voltage V3 of non-contact plug 2 and outputting a detection signal. Detection circuit 21
A signal conversion circuit 22 for outputting an AC signal corresponding to the detection signal, and an AC signal output from the signal conversion circuit 22 to generate a magnetic flux signal as a magnetic signal.
The output of the non-contact plug 2 is connected to the terminal device 3. The power transmitting primary coil L1 and the power receiving secondary coil L2 constitute a power transmitting / receiving transformer T1 which can be detached and attached. The primary signal receiving coil 14 and the secondary signal transmitting coil 23 are detached and attached. A possible signal transfer transformer T2 is configured.

However, when the power transmitting / receiving transformer T1 and the signal transmitting / receiving transformer T2 are arranged close to each other as in the circuit configuration shown in FIG. 10, a part of the magnetic flux F3 is partially dispersed due to the spread of the magnetic flux F3. Since the receiving coil 14 and the secondary side signal transmitting coil 23 are linked, noise enters the signal transmitting / receiving transformer T2 and the accurate non-contact plug 2
Of the output terminal voltage V3 cannot be fed back to the non-contact outlet 1. Therefore, an embodiment for improving the above-described problem is shown in FIGS.

FIG. 11 shows that a partition wall A1 made of a magnetic material that easily conducts magnetism is provided between the non-contact outlet 1, the non-contact plug 2, and the signal transfer transformer T2, and is generated by the power transmission primary coil L1. By concentrating the magnetic flux F3 on the barrier A1, the magnetic flux linked to the signal transmitting / receiving transformer T2 among the magnetic flux F3 is reduced.

FIG. 12 shows a power transmission primary coil L1 and a power reception secondary coil L2 wound around a core A2 made of a magnetic material, and a power transmission primary coil L1 and a power reception secondary coil L2. And a magnetic flux F3 generated by the primary coil L1 for power transmission
2, the degree of spread of the magnetic flux F3 is reduced, and of the magnetic flux F3, the magnetic flux linked to the signal transmitting / receiving transformer T2 is reduced.

FIG. 13 shows a power transmission primary coil L1 and a power reception secondary coil L2 which are wound around a generally used transformer core A3 made of a magnetic material and having an opening. The primary coil L1 for power transmission and the secondary coil L2 for power reception are arranged to face each other in the axial direction, and the magnetic flux F3 generated by the primary coil L1 for power transmission is used for the core A.
3, the degree of spread of the magnetic flux F3 is reduced, and of the magnetic flux F3, the magnetic flux linked to the signal transmitting / receiving transformer T2 is reduced. In FIG. 13, since a part of the magnetic flux F3 leaks from the opening 122 of the core A3, the signal transfer transformer T2 is installed on the non-opening 123 side of the core A3 so that the magnetic flux does not interlink. .

In the embodiment shown in FIG. 14, the output terminal voltage V3 is input to the signal conversion circuit 24, and the signal conversion circuit 24 outputs a signal corresponding to the output terminal voltage V3. Is connected to the output of the signal conversion circuit 24 from which the signal is output, and the other end is connected to one end of a power receiving secondary coil. The magnetic flux F3a generated in the power transmission primary coil L1 and interlinking with the power reception secondary coil L2 and the power generation primary coil L1
The direction of the magnetic flux F3b interlinking with the secondary signal receiving coil 14 and the magnetic flux signal F4 generated by the secondary signal transmitting coil 23
Power transmission 1 so that the directions of
By making the directions of the windings of the secondary coil L1 and the primary signal receiving coil 14 and the windings of the power receiving secondary coil L2 and the secondary signal transmitting coil 23 opposite to each other, Magnetic flux signal F4 generated in the secondary signal transmission coil 23
Is the magnetic flux F generated in the power transmission primary coil L1.
3a and F3b, and the signal transmitting / receiving transformer T2 has a magnetic flux F generated by the power transmission primary coil L1.
3a and F3b are less likely to be affected.

Further, as shown in the characteristic 117b of the output terminal voltage V3 with respect to the load current I3 in FIG. 33, the output terminal voltage V3 tends to increase as the load becomes closer, and the output terminal voltage V3 increases as the load decreases. Is difficult to stabilize. Although the feedback control system can be designed to cover the entire load region by the thinning control, the control circuit components are increased due to the improvement of the resolution of the control signal, the improvement of the response speed, and the enhancement of the noise resistance, which is disadvantageous in cost and size. However, by connecting the resistor R1 in parallel between the output terminals of the non-contact plug 2 as shown in FIG.
As shown in the characteristic 117f of the output terminal voltage V3 with respect to No. 3, the current 115 is always passed through the resistor R1 and the region 11
1, the output terminal voltage V3 can be stabilized. Further, when the load changes suddenly, the transient output terminal voltage V
3, the constant voltage diode ZD1 is connected in parallel between the output terminals of the non-contact plug 2 as shown in FIG. 14, so that the output terminal voltage V3 can always be stabilized. The output terminal voltage V3 at the time of sudden load change as described above is less frequently increased, and the increased voltage is also small, so that the loss of the constant voltage diode ZD1 is small. In this embodiment, a constant voltage diode is used, but any voltage clamp element may be used.

Next, FIG. 15 shows that the electrical information of the non-contact plug 2 necessary for the thinning control is obtained from the change in the magnetic flux F3 generated in the power transmission primary coil L1, and is generated in the power transmission primary coil L1. The change in the magnetic flux F3 is detected by the magnetic flux detection coil 1.
The detection is performed at 4a, and thinning control of the inverter circuit 11 is performed based on the detection result. In non-contact transmission, if the transmitted power increases, the magnetic flux F3 generated in the power transmission primary coil L1 also increases in proportion to the power, and the output terminal voltage decreases in inverse proportion to the power. The above characteristics are the same characteristics in one system,
If the change in the magnetic flux F3 generated in the power transmission primary coil L1 is detected by the magnetic flux detection coil 14a, information on the output terminal voltage of the non-contact plug 2 can be obtained indirectly, and the inverter circuit 11 is thinned out. be able to. The circuit shown in FIG. 15 includes a power transmission primary coil L1 and a power reception 2
The magnetic flux F3 is linked to the magnetic flux detecting coil 14a by increasing the spread and leakage of the magnetic flux F3 by using the next coil L2 as an air core.

The circuit shown in FIG. 16 is a commonly used circuit in which the primary coil L1 for power transmission and the secondary coil L2 for power reception of the circuit shown in FIG. And the magnetic flux detecting coil 14a is arranged near the opening 122, so that the opening 1 of the magnetic flux F3 is provided.
The magnetic flux leaking from 22 is linked to the magnetic flux detection coil 14a.

As described above, the present invention can stabilize a required voltage in a wide load region.

FIG. 17 shows the appearance of an example of the non-contact power transmission system of the present invention used in a bathroom. The non-contact outlet 1 embedded in the wall 200 is provided with a seal 15 on an outer peripheral portion in contact with the surface of the wall 200 to enhance waterproofness. The power supply circuit 10, the inverter circuit 11, the switching control circuit 12, and the signal conversion circuit 13 are built in the non-contact outlet 1, and are disposed in the circuit block X 1 connected to the AC power supply 4 and the recess 19. The primary coil L1 for power transmission provided and the primary signal receiving coil 14 similarly arranged with respect to the concave portion 19 are provided, and the non-contact outlet 1 can be used on the surface on the non-contact plug 2 side. , An outlet power indicator LED 16 that is lit when the power is on.
The non-contact plug 2 is fitted into the recess 19 of the non-contact outlet 1 when energized, and has a power transmission 1
A power receiving secondary coil L2 provided to face the primary coil L1, and a secondary signal transmitting coil 23 provided to face the primary signal receiving coil 14.
Rectifying / smoothing circuit 20, output terminal voltage detecting circuit 21
And a circuit block X2 incorporating the signal conversion circuit 22
And a cable cord 26 for transmitting electric power to the device 3. The terminal device 3 is connected to the cable cord 26 and transmitted with electric power, and is turned on when the non-contact plug 2 is in a usable state on the surface. An energization display LED 25 is provided.

FIG. 18 is a view of FIG. 17 as viewed from the non-contact plug 2 side. Non-contact outlet 1 and non-contact plug 2
It is necessary for the user to indicate whether the non-contact outlet 1 is usable, and an outlet power-on display LED 16 that is lit when the non-contact outlet 1 is in the usable state is provided on the surface of the non-contact plug 2 of the non-contact outlet 1, On the surface of the non-contact plug 2, there is provided an outlet energization display LED 16 which is turned on when the non-contact plug 2 is in a usable state. In addition, since it is intended for a wide load area, information such as how much load the terminal device 3 currently using does not exceed the usage limit is important. This information can be obtained from the thinning rate of the thinning control. That is, when the thinning rate is large, the load is small, and when the thinning rate is small, the load is large. Further, the minimum thinning rate is set in advance, and when the thinning rate falls below the minimum thinning rate and goes beyond the target load region, the output terminal voltage V3 drops sharply, so that the output terminal voltage V3 becomes equal to or lower than the predetermined voltage value. Thus, the overload state can be determined. The load amount indicator 17 provided on the surface of the non-contact plug 2 of the non-contact outlet 1 displays the amount of the used load.

FIG. 19 shows that a non-contact plug 2a for a 12V device connected to the terminal device 3a for 12V and a non-contact plug 2b for the 24V device connected to the terminal device 3b for 24V are connected to one non-contact outlet. 1 indicates that power can be transmitted. As described above, since the thinning control of the non-contact power transmission system of the present invention can be performed even when the load area is wide, even if the number of turns of the power transmission primary coil L1 of the non-contact outlet 1 is constant, the non-contact power supply for Plugs 2a and 24
Secondary coil L for power reception with non-contact plug 2b for V equipment
By changing the number of turns of the secondary coil 2a and the secondary coil L2b for power reception, each output terminal voltage V3 can be stabilized, or can be stabilized to an arbitrary voltage.

In the non-contact power transmission system, the power that can be transmitted decreases as the distance between the power transmission primary coil L1 and the power reception secondary coil L2 increases, so that the non-contact outlet 1 and the non-contact plug 2 It is necessary to keep the relative positional relationship with the predetermined positional relationship. FIG. 20 shows a state in which the non-contact plug 2 is not completely fitted in the concave portion 19 of the non-contact outlet 1. In such a case, the power transmission from the non-contact outlet 1 to the non-contact plug 2 is performed. Need to stop. Therefore, the non-contact outlet 1 is provided with the mechanical contact 18 arranged with respect to the recess 19, and only when the mechanical contact 18 is turned on, the inverter circuit 11 built in the circuit block X1 of the non-contact outlet 1 operates. Electric power is transmitted from the non-contact outlet 1 to the non-contact plug 2, and the non-contact plug 2 is provided with a permanent magnet 30 so as to face the mechanical contact 18 when fitted. Mechanical contact 18
Is a switch operated by the magnetic force of the permanent magnet 30,
In FIG. 20, the non-contact plug 2 is the non-contact outlet 1
Of the permanent magnet 30
And the mechanical contact 18 are too far apart, and the magnetic force of the permanent magnet 30 cannot operate the mechanical contact 18. FIG.
Shows a state in which the non-contact plug 2 is completely fitted into the concave portion 19 of the non-contact outlet 1, the magnetic force of the permanent magnet 30 can operate the mechanical contact 18, and the circuit block of the non-contact outlet 1 The inverter circuit 11 built in the X1 operates to transmit power from the non-contact outlet 1 to the non-contact plug 2. Since the permanent magnet 30 is a permanent magnet, the primary signal receiving coils 14, 2
It does not adversely affect the magnetic flux signals of the secondary signal transmission coil 23 and the magnetic flux detection coil 14a. Further, the outlet energization display LED 16 can be turned on when the mechanical contact 18 is turned on, and the plug energization display LED 25 can be turned on by monitoring the output terminal voltage V3.

Next, it is desirable that the connection between the non-contact plug 2 and the terminal device 3 be integrated when used around water. However, even when not used around water or when used around water, Since the simple waterproofing may be used when the terminal device 3 is not used, the connection between the non-contact plug 2 and the terminal device 3 may be detachable. In this way, if only one non-contact outlet 1 and one non-contact plug 2 are provided, it is economical since only the terminal device 3 needs to be prepared according to the intended use. In FIG. 22, the terminal devices 3c and 3d include cable cords 26c and 26d, and the terminals of the cable cords 26c and 26d have connectors 2 respectively.
7c and 27d are connected to each other, and are detachable from sockets 28c and 28d provided on the surface of the non-contact plug 2 and connected to the output end of the non-contact plug 2, so that one non-contact plug 2 A plurality of terminal devices 3c and 3d can be connected. In FIG. 23, the terminal device 3
e has a cable cord 26e, and the cable cord 26e
e, a power receiving coil L5 is connected to the terminal, and a power transmitting coil L4 connected to the output end of the non-contact plug 2 is provided near the surface of the non-contact plug 2;
Are fitted into the recesses 29 on the surface of the non-contact plug 2 and power is transmitted from the power transmission coil L4 by electromagnetic induction. In FIG. 23, the output voltage of the circuit block X2 applied to the power transmission coil L4 is a high-frequency voltage.

Also, use around water like in a bathroom,
When a low-voltage output is required to prevent electric shock, voltage rise in the non-contact plug 2 and the terminal device 3 must be suppressed as much as possible even when the non-contact outlet 2 fails. In the present invention, since power is transmitted using the power transmission transformer T1 which can be detached and attached, a voltage proportional to the amplitude of the high-frequency voltage V1 applied to the primary-side power transmission coil L1 of the non-contact outlet 1 becomes non-voltage. It is induced in the secondary side power receiving coil L2 of the contact plug 2. Therefore, if the inverter circuit on the non-contact outlet 1 side or the control circuit fails,
When a high voltage is applied to the secondary-side power transmitting coil L1, the voltage V2 induced in the secondary-side power receiving coil L2 also increases, and exceeds the controllable region to the output terminal voltage V3 of the non-contact plug 2. High voltage may be applied. Therefore, in the present invention, as shown in FIG. 2, the inverter circuit 11 uses a half-bridge circuit, so that the voltage V1 across the primary-side power transmission coil L1 is equal to the voltage -E / 2 and the voltage E / 2, and the voltage V2 induced in the secondary-side power receiving coil L2 does not increase more than a certain voltage, thus providing a safe system.

As shown in FIG. 25, the capacitor C2 in FIG. 2 may have capacitors C21 and C22 connected between the center tap of the power receiving secondary coil L2 and the other terminals, or as shown in FIG. The same effect can be obtained by connecting capacitors C21 and C22 in parallel with the diodes D3 and D4. This is because the capacitor C2 is a capacitor that acts on high-frequency AC, and the equivalent circuits of AC in FIGS. 2, 25, and 26 are equivalent. Can be obtained. As long as the waveform conditions of the present invention are satisfied, they are included in the present invention.
The same applies to the case where 2 does not have a center tap.

[0062]

According to the first aspect of the present invention, there is provided a power supply circuit for outputting a DC voltage, an inverter circuit for converting the DC voltage to a high-frequency voltage having a constant frequency, and a power transmission device for receiving the high-frequency voltage from the inverter circuit. Non-contact outlet composed of a secondary coil, a secondary coil for receiving power, and a secondary coil for generating high-frequency voltage by forming a detachable transformer structure from the primary coil for transmitting power and the secondary coil for receiving power A non-contact plug composed of a rectifying and smoothing circuit that rectifies and smoothes the high-frequency voltage induced in the non-contact power transmission device composed of a terminal device serving as a load connected to the output terminal of the non-contact plug; The non-contact outlet transmits the output terminal voltage of the non-contact plug to a target load area from the inverter circuit to the power transmission primary coil. A non-contact power transmission device capable of stabilizing the output terminal voltage to a constant value over a wide load range by providing control means for performing thinning control for thinning and stabilizing a high-frequency voltage supplied to the power supply device. This has the effect.

According to a second aspect of the present invention, in the first aspect of the invention, when the output terminal voltage of the non-contact plug exceeds a predetermined voltage, the control means transmits the signal from the inverter circuit to the primary coil for power transmission. The supply of the high-frequency voltage is thinned out for a certain period of time, and if the output terminal voltage of the non-contact plug is higher than the predetermined voltage after the thinning out for the certain time, the supply of the high-frequency voltage to the power transmission primary coil is performed again. If the output terminal voltage of the non-contact plug falls below a predetermined voltage after performing the above-described decimation for a certain period of time, the power is output until the output terminal voltage of the non-contact plug exceeds the predetermined voltage. Characterized by continuing the operation of continuously supplying the high-frequency voltage to the power transmission primary coil,
There is an effect that a non-contact power transmission device capable of stabilizing an output terminal voltage to a constant value in a wide load range can be provided.

According to a third aspect of the present invention, in the first or second aspect, the non-contact plug converts information representing an electric state inside the non-contact plug into a magnetic signal, transmits the magnetic signal to the non-contact outlet, and performs the control. The means forms a control signal for thinning control based on the magnetic signal, and controls the thinning of the inverter circuit by the control signal.To use the magnetic signal as a feedback signal for voltage stabilization, There is an effect that it is possible to provide a non-contact power transmission device capable of stabilizing an output terminal voltage to a constant value over a wide load range without being affected by surrounding brightness and dirt.

According to a fourth aspect of the present invention, in any one of the first to third aspects of the present invention, the inverter circuit is a half-bridge type partial resonance inverter, and can suppress an increase in output voltage at the time of failure. There is an effect that can be.

According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the power receiving secondary coil has a center tap, and the rectifying and smoothing circuit is connected in series to both output terminals other than the center tap of the power receiving secondary coil. And a full-wave rectifying unit that connects the other ends of the rectifiers that are not connected to the power receiving secondary coils of the rectifiers connected in opposite directions to each other, and connects a choke coil to a connection midpoint of the rectifiers. This is advantageous in that the rectifier can be reduced in size.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects of the present invention, a capacitor is connected in parallel to the power receiving secondary coil, and the secondary coil is connected from the primary side by load matching. There is an effect that the active power that can be transmitted to the next side can be increased.

According to a seventh aspect of the present invention, in the sixth aspect of the present invention, the capacitance value of the capacitor is the maximum value of the high-frequency voltage supplied to the power transmission primary coil at the time of the maximum load in the target load region. It is characterized in that the polarity reversal time is the capacitance value at which the oscillation voltage generated at both ends of the capacitor becomes the maximum value or the minimum value, and the optimum load matching is performed to improve the circuit efficiency. There is an effect that can be.

According to an eighth aspect of the present invention, in any one of the third to seventh aspects of the present invention, the non-contact outlet is provided with a primary signal receiving coil, and the non-contact plug is disposed to face the primary signal receiving coil. A secondary signal transmitting coil which forms a transformer structure detachable from the primary signal receiving coil is provided, and the secondary signal transmitting coil converts information representing an electrical state inside the non-contact plug into an AC voltage. Is input, generates a magnetic flux signal as a magnetic signal, the primary side signal receiving coil is induced voltage by the magnetic flux signal,
The control means performs the thinning-out control on the inverter circuit by a control signal based on the induced voltage, and uses a magnetic flux signal as a feedback signal for voltage stabilization. There is an effect that it is possible to provide a non-contact power transmission device capable of stabilizing an output terminal voltage to a constant value over a wide load range without receiving the power.

According to a ninth aspect of the present invention, in accordance with the eighth aspect of the present invention, there is provided a method according to any one of the preceding claims, wherein the power transmitting primary coil and the primary signal receiving coil and the power receiving secondary coil and the secondary signal transmitting coil are connected to each other. A magnetic shield partition made of a magnetic material is provided between at least one of the gaps to reduce the magnetic flux generated by the current transmission / reception transformer linked to the signal transmission / reception transformer, thereby achieving accurate voltage stabilization. There is an effect that a magnetic flux signal can be transmitted and received.

According to a tenth aspect of the present invention, in the ninth aspect of the present invention, the primary coil for power transmission and the secondary coil for power reception are wound around a core made of a magnetic material, and the cores are mutually attached to the core. It is characterized by being axially opposed to each other, reducing the magnetic flux generated by the current transmitting / receiving transformer interlinking with the signal transmitting / receiving transformer, enabling transmission and reception of magnetic flux signals for accurate voltage stabilization. This has the effect.

According to an eleventh aspect of the present invention, in the ninth aspect of the present invention, the primary coil for power transmission and the secondary coil for power reception are each a bottomed cylinder having an opening in a direction perpendicular to the axial direction of the coil. Wound around a core made of a magnetic material of a mold, and the cores are arranged to face each other in the axial direction of the core. The arrangement is characterized in that the magnetic flux generated in the current transmission / reception transformer linked to the signal transmission / reception transformer is reduced, so that a magnetic flux signal for accurate voltage stabilization can be transmitted and received.

According to a twelfth aspect of the present invention, in any one of the eighth to eleventh aspects, the secondary-side signal transmitting coil receives a signal obtained by converting information representing an electric state inside the non-contact plug into an AC voltage. And generating a magnetic flux signal having a phase opposite to that of the magnetic flux generated by the power transmission primary coil, and has an effect that a flux signal for accurate voltage stabilization can be transmitted and received. .

According to a thirteenth aspect, in the twelfth aspect, one terminal of the secondary signal transmission coil is connected to one of the terminals of the power receiving secondary coil. Thus, there is an effect that a magnetic flux signal for accurate voltage stabilization can be transmitted and received.

According to a fourteenth aspect of the present invention, in any one of the third to seventh aspects of the present invention, the non-contact outlet includes a power transmitting primary coil and a power receiving secondary coil near the power transmitting primary coil. A magnetic flux detection coil for detecting a magnetic flux generated therebetween, wherein the magnetic flux detection coil detects a magnetic flux generated in the power transmission primary coil as a magnetic signal, and converts the magnetic flux to the detected magnetic flux from the magnetic flux detection coil. The control means performs thinning-out control of the inverter circuit based on the voltage output in response thereto, and has an effect that a magnetic flux signal for accurate voltage stabilization can be received.

According to a fifteenth aspect, in the fourteenth aspect, the primary coil for power transmission and the secondary coil for power reception are each a bottomed cylinder having an opening in a direction perpendicular to an axial direction of the coil. And a magnetic flux detecting coil disposed near an opening of the core of the power transmission primary coil. The magnetic flux detecting coil is disposed near the core of the primary coil for power transmission. Thus, there is an effect that a magnetic flux signal for accurate voltage stabilization can be received.

According to a sixteenth aspect of the present invention, in any one of the first to fifteenth aspects, one non-contact outlet is adapted to a plurality of non-contact plugs having different output voltages, and each non-contact plug is a target load. It is characterized by having the control means for keeping the output voltage of each of the non-contact plugs within a predetermined voltage range in the entire region including the region, and has an effect of being economical.

A seventeenth aspect of the present invention is characterized in that, in any one of the first to sixteenth aspects, a resistor is connected in parallel to the output terminal of the non-contact plug, and the output terminal voltage is kept constant over a wide load range. There is an effect that a contactless power transmission device that can be stabilized can be provided.

According to the eighteenth aspect of the present invention, in any one of the first to seventeenth aspects, when the non-contact plug is not connected to a predetermined position of the non-contact outlet, the control means transmits power from the inverter circuit. It is characterized by limiting the output supplied to the primary coil for use, and has an effect that high safety and reliability can be provided.

According to a nineteenth aspect of the present invention, in the eighteenth aspect of the invention, the non-contact outlet has a switch function of controlling the supply of the high-frequency voltage from the inverter circuit to the power transmission primary coil. A driver for controlling the on / off state of the switch function, and when the non-contact plug is connected to a predetermined position of the non-contact outlet, the switch function is operated so that the control means can control the primary power transmission from the inverter circuit. It is characterized in that high-frequency voltage can be supplied to the coil, and there is an effect that high security and reliability can be provided.

According to a twentieth aspect of the present invention, in the nineteenth aspect, the switch function of the non-contact outlet comprises a mechanical contact, a driving body provided in the non-contact plug comprises a magnet, and the non-contact plug is a non-contact outlet. When coupled to a predetermined position, the mechanical contact operates by the magnetic force of the magnet, and the control means enables supply of a high-frequency voltage from the inverter circuit to the primary coil for power transmission, thereby providing high safety. And reliability can be provided.

According to a twenty-first aspect of the present invention, in any one of the first to twentieth aspects, when the non-contact plug is connected to a predetermined position of the non-contact outlet, the non-contact plug is used for at least one of the non-contact plug and the non-contact outlet. It is characterized in that display for notifying the possibility is performed, and there is an effect that it is possible to determine whether or not the system or the device can be used.

According to a twenty-second aspect of the present invention, in any one of the first to twenty-first aspects, at least one of the non-contact outlet and the non-contact plug is connected to an output terminal of the non-contact plug. And a display unit for displaying at least one of the output voltage of the non-contact plug is added, and it is possible to determine whether or not the system or the device can be used.

According to a twenty-third aspect of the present invention, in any one of the first to twenty-second aspects, the terminal device connected to the output terminal of the non-contact plug is detachably attachable to and detachable from the non-contact plug. There is an effect that an unspecified terminal device can be used.

According to a twenty-fourth aspect of the present invention, in the twenty-third aspect, the power supply from the output terminal of the non-contact plug to the terminal device is supplied by magnetic coupling. There is an effect that it can be used.

According to a twenty-fifth aspect of the present invention, in any one of the first to twenty-fourth aspects, between the output terminals of the non-contact plug,
The invention is characterized in that a voltage clamp element is connected, and there is an effect that high safety and reliability can be provided.

As described above, the non-contact power transmission system constituted by the present invention is based on the background of safety and security and high reliability.
The water surrounding environment such as a bathroom is electrified, and various electric devices can meet various user needs.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention.

FIG. 2 is a specific circuit configuration diagram showing an embodiment of the present invention.

FIG. 3 is a diagram illustrating characteristics of an example of the present invention.

FIG. 4 is a diagram showing characteristics of the embodiment of the present invention.

FIG. 5 is a diagram showing characteristics of the example of the present invention.

FIG. 6 is a diagram showing characteristics of the example of the present invention.

FIG. 7 is a diagram showing characteristics of the example of the present invention.

FIG. 8 is a diagram showing characteristics of the example of the present invention.

FIG. 9 is a diagram showing characteristics of the example of the present invention.

FIG. 10 is a circuit configuration diagram showing an embodiment of the present invention.

FIG. 11 is a circuit configuration diagram showing an embodiment of the present invention.

FIG. 12 is a circuit configuration diagram showing an embodiment of the present invention.

FIG. 13 is a circuit diagram showing an embodiment of the present invention.

FIG. 14 is a circuit configuration diagram showing an embodiment of the present invention.

FIG. 15 is a circuit diagram showing an embodiment of the present invention.

FIG. 16 is a circuit configuration diagram showing an embodiment of the present invention.

FIG. 17 is an external view showing an embodiment of the present invention.

FIG. 18 is an external view showing an embodiment of the present invention.

FIG. 19 is an external view showing an embodiment of the present invention.

FIG. 20 is an external view showing an embodiment of the present invention.

FIG. 21 is an external view showing an embodiment of the present invention.

FIG. 22 is an external view showing an embodiment of the present invention.

FIG. 23 is an external view showing an embodiment of the present invention.

FIG. 24 is a diagram showing characteristics of the example of the present invention.

FIG. 25 is a circuit diagram showing an embodiment of the present invention.

FIG. 26 is a circuit diagram showing an embodiment of the present invention.

FIG. 27 is a circuit configuration diagram showing a conventional example of the present invention.

FIG. 28 is a configuration diagram showing a power transfer transformer according to a conventional example of the present invention.

FIG. 29 is a circuit configuration diagram showing a conventional example of the present invention.

FIG. 30 is a diagram showing characteristics of a conventional example of the present invention.

FIG. 31 is a circuit configuration diagram showing a conventional example of the present invention.

FIG. 32 is a circuit configuration diagram showing a conventional example of the present invention.

FIG. 33 is a diagram showing characteristics of a conventional example of the present invention.

FIG. 34 is a diagram showing characteristics of a conventional example of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Non-contact outlet 2 Non-contact plug 3 Terminal equipment 10 Power supply circuit 11 Inverter circuit 20 Rectifier smoothing circuit E DC voltage V1 High frequency voltage V2 High frequency voltage L1 Primary coil for power transmission L2 Secondary coil for power reception

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) H02M 3/335 H01F 23/00 B (72) Inventor Motoharu Muto 1048 Odakadoma, Kadoma-shi, Osaka Matsushita Electric Works Co., Ltd. F term (reference) 5G065 AA00 DA06 DA07 EA06 HA04 JA01 LA01 MA01 MA02 MA03 MA09 MA10 NA01 NA02 NA03 NA09 5H730 AA17 AS01 BB25 BB26 BB57 BB75 CC01 EE03 EE08 EE59 FD01 FF18 FG07

Claims (25)

[Claims] 1. A power supply circuit for outputting a DC voltage, an inverter circuit for converting the DC voltage into a high-frequency voltage having a constant frequency, and a power transmission primary coil supplied with the high-frequency voltage from the inverter circuit. A non-contact outlet, a power receiving secondary coil configured to be detachable from and detachable from the power transmitting primary coil to generate a high-frequency voltage, and a high-frequency voltage induced to the power receiving secondary coil. In a non-contact power transmission device including a non-contact plug including a rectifying and smoothing circuit for performing rectification and smoothing, and a terminal device serving as a load connected to an output terminal of the non-contact plug, the non-contact outlet is a target. The output terminal voltage of the non-contact plug with respect to the load area is set to a high frequency supplied to the power transmission primary coil from the inverter circuit. A non-contact power transmission device comprising control means for performing thinning control for stabilizing by thinning a voltage. 2. The control device according to claim 1, wherein when the output terminal voltage of the non-contact plug exceeds a predetermined voltage, the supply of the high-frequency voltage from the inverter circuit to the primary coil for power transmission is reduced for a certain period of time. If the output terminal voltage of the non-contact plug exceeds the predetermined voltage after performing the time culling, the supply of the high-frequency voltage to the power transmission primary coil is repeated for a certain time again, and the constant time culling is repeated. If the output terminal voltage of the non-contact plug falls below the predetermined voltage after performing the above, the supply of the high-frequency voltage to the power transmission primary coil until the output terminal voltage of the non-contact plug exceeds the predetermined voltage 2. The non-contact power transmission device according to claim 1, wherein an operation of continuously performing the operation is continued. 3. The non-contact plug converts information representing an electric state inside the non-contact plug into a magnetic signal and transmits the magnetic signal to a non-contact outlet, and the control means performs thinning control based on the magnetic signal. 3. The non-contact power transmission device according to claim 1, wherein a control signal is formed, and the inverter circuit is thinned out by the control signal. 4. The non-contact power transmission device according to claim 1, wherein the inverter circuit is a half-bridge type partial resonance inverter. 5. The power receiving secondary coil includes a center tap, and the rectifying / smoothing circuit includes a rectifying element power connected in series and in opposite directions to both output terminals of the power receiving secondary coil that are not center taps. The non-contact device according to claim 4, further comprising a full-wave rectifier that connects the other ends of the rectifiers that are not connected to the power receiving secondary coil, and that connects a choke coil to a connection midpoint of the rectifier. Power transmission device. 6. The non-contact power transmission device according to claim 1, wherein a capacitor is connected in parallel to the power receiving secondary coil. 7. A capacitance value of the capacitor is generated at both ends of the capacitor when the polarity of the high-frequency voltage supplied to the primary coil for power transmission is inverted at the time of maximum load in a target load region. 7. The non-contact power transmission device according to claim 6, wherein the capacitance value coincides with the time when the oscillating voltage reaches a maximum value or a minimum value. 8. A non-contact outlet is provided with a primary side signal receiving coil, and a non-contact plug is arranged opposite to the primary side signal receiving coil to form a transformer structure detachable from and detachable from the primary side signal receiving coil. A secondary-side signal transmission coil is provided, the secondary-side signal transmission coil receives a signal obtained by converting information representing an electrical state inside the non-contact plug into an AC voltage, and generates a magnetic flux signal as a magnetic signal; 8. A primary-side signal receiving coil in which a voltage is induced by the magnetic flux signal, and wherein the control means performs the thinning-out control of an inverter circuit by a control signal based on the induced voltage. A non-contact power transmission device according to claim 1. 9. A magnetic material comprising a magnetic material between at least one of a power transmitting primary coil and a primary signal receiving coil and at least one of a power receiving secondary coil and a secondary signal transmitting coil. 9. The non-contact power transmission device according to claim 8, further comprising a shielding partition. 10. A primary coil for power transmission and a secondary coil for power reception.
The non-contact power transmission device according to claim 9, wherein the next coil is wound around a core made of a magnetic material, and the cores are arranged to face each other in the axial direction of the core. 11. A power transmission primary coil and a power reception 2
And a next coil wound around a core made of a bottomed cylindrical magnetic material having an opening in a direction perpendicular to the axial direction of the coil, and the cores are arranged so as to face each other in the axial direction of the core. 10. A primary side signal receiving coil and a secondary side signal transmitting coil are arranged in the vicinity of the non-opening portion of the above.
A non-contact power transmission device according to claim 1. 12. A secondary signal transmission coil receives a signal obtained by converting information representing an electric state inside a non-contact plug into an AC voltage, and has a phase opposite to that of a magnetic flux generated by a power transmission primary coil. The non-contact power transmission device according to any one of claims 8 to 11, wherein a magnetic flux signal having a phase of: 13. The non-contact power transmission device according to claim 12, wherein one terminal of the secondary-side signal transmission coil is connected to one of terminals of the power reception secondary coil. 14. A non-contact outlet, comprising: a magnetic flux detecting coil for detecting a magnetic flux generated between the power transmitting primary coil and the power receiving secondary coil in the vicinity of the power transmitting primary coil; The magnetic flux detection coil detects a magnetic flux generated in the power transmission primary coil as a magnetic signal, and based on a voltage output from the magnetic flux detection coil in accordance with the detected magnetic flux, the control means includes an inverter circuit. The non-contact power transmission device according to any one of claims 3 to 7, wherein thinning control is performed. 15. A primary coil for power transmission and a secondary coil for power reception.
A secondary coil is provided on a core made of a bottomed cylindrical magnetic material having an opening in a direction perpendicular to the axial direction of the coil, and the cores are arranged to face each other in the axial direction of the core, and the power transmission The non-contact power transmission device according to claim 14, wherein the magnetic flux detection coil is arranged near an opening of a core of the primary coil. 16. One non-contact outlet is adapted to a plurality of non-contact plugs having different output voltages, and controls the output voltage of each of the non-contact plugs in an entire region including a load region targeted by each of the non-contact plugs. 16. The control device according to claim 1, wherein said control means is controlled to fall within a voltage range.
The wireless power transmission device according to any one of the above. 17. The non-contact power transmission device according to claim 1, wherein a resistor is connected in parallel to an output terminal of the non-contact plug. 18. When the non-contact plug is not connected to a predetermined position of the non-contact outlet, the control means limits an output supplied from the inverter circuit to the primary coil for power transmission. The non-contact power transmission device according to claim 1. 19. The non-contact outlet has a switch function for controlling the supply of a high-frequency voltage from the inverter circuit to the power transmission primary coil, and the non-contact plug is a drive for controlling the on / off state of the switch function. The control means enables the supply of a high-frequency voltage from the inverter circuit to the primary coil for power transmission by operating the switch function when the non-contact plug is coupled to a predetermined position of the non-contact outlet. The wireless power transmission device according to claim 18, wherein: 20. The switch function of the non-contact outlet comprises a mechanical contact, and a driving body provided in the non-contact plug comprises a magnet, and when the non-contact plug is coupled to a predetermined position of the non-contact outlet, the magnetic force of the magnet causes the driving force. 20. The non-contact power transmission device according to claim 19, wherein a mechanical contact is operated, and the control unit enables supply of a high-frequency voltage from the inverter circuit to the power transmission primary coil. 21. When the non-contact plug is connected to a predetermined position of the non-contact outlet, a display for informing that at least one of the non-contact plug and the non-contact outlet can be used is displayed. 20. The non-contact power transmission device according to any one of 20. 22. At least one of a non-contact outlet and a non-contact plug displays at least one of a load power of a terminal device connected to an output terminal of the non-contact plug and an output voltage of the non-contact plug. 22. The non-contact power transmission device according to claim 1, further comprising a display unit. 23. The non-contact power transmission device according to claim 1, wherein a terminal device connected to an output terminal of the non-contact plug is detachably detachable from the non-contact plug. 24. The wireless power transmission device according to claim 23, wherein power is supplied from the output terminal of the wireless plug to the terminal device by magnetic coupling. 25. A voltage-clamping element is connected between output terminals of a non-contact plug.
5. The non-contact power transmission device according to any one of the above items 4.