JP2003348776A - Non-contact power supply device and power / signal transmission device using the same - Google Patents

Abstract

(57) [Problem] To provide a non-contact power supply device capable of responding to any load, performing efficient and stable power control, and a power / signal transmission device using the same. A non-contact power supply device includes an output transformer having a primary winding arranged on a first unit side and a secondary winding arranged on a second unit side, and a power supply circuit including a switching element. , Power receiving circuit 104, load 112
Monitor the load voltage appearing at both ends of the output transformer 103, generate a load voltage signal composed of a pulse-like voltage having an amplitude corresponding to the load voltage, and superimpose the generated load voltage signal on the secondary winding of the output transformer 103. A circuit 122, a load voltage signal detection circuit 123 for detecting a load voltage signal from the primary winding of the output transformer 103, and a load voltage signal detection circuit 123
Generates a control pulse that is pulse width modulated by the detection signal from
And a pulse width modulation circuit 111 for performing WM control.

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 supply for transmitting electric power between two units in a non-contact manner, and a non-contact form between the two units using the non-contact power supply. The present invention relates to a power / signal transmission device for transmitting power and a signal.

[0002]

2. Description of the Related Art As a conventional power transmission device, for example, there is one disclosed in Japanese Patent Application Laid-Open No. H11-341711.

FIG. 6 is a block diagram showing a configuration example of the above-described conventional power transmission device. 6, the signal transmission load circuit 2 connected to the secondary winding 4b of the output transformer 4
1, a pulse-shaped load signal current corresponding to the load current is superimposed on its own current, the load signal current is transmitted to the primary side of the output transformer 4 by electromagnetic induction coupling, and the primary winding 4a, the diode 9, A load signal current flows through the resistor 7 and is detected by the current detection circuit 10, and the oscillation frequency of the oscillation circuit 12 is varied by the oscillation frequency variable circuit 11 according to the detected value.
By changing the switching cycle of the MOS transistor 6 and changing the chopping cycle of the DC voltage on the primary side,
When there is no load and light load, small power is supplied to the secondary side when a load signal current is detected from the secondary side.

[0004]

However, in the above-described conventional power transmission device, the range of load fluctuation that can be handled is narrow, the transmission efficiency deteriorates under heavy load, and control must be performed on the secondary side. Therefore, there is a problem that the number of parts increases.

Accordingly, the present invention has been made in view of the above-described conventional problems, and has been made in consideration of the above-described problems, and has been made to be able to cope with any load, to perform efficient and stable power control, and to provide a power / signal transmission apparatus using the same. It is intended to provide.

[0006]

According to a first aspect of the present invention, there is provided a non-contact power supply device for transmitting power between a first unit and a second unit, comprising: A secondary winding is arranged on the first unit side and 2
A secondary winding disposed on the side of the second unit; and an output transformer disposed on the side of the first unit, including a switching element, converting DC power from a DC power supply into AC power and converting the DC power to AC power. A power supply circuit for supplying to the primary winding; and a power receiving circuit disposed on the second unit side, for converting AC power supplied from the secondary winding of the output transformer to DC power and supplying the DC power to a load. Monitoring the load voltage appearing at both ends of the load, generating a load voltage signal composed of a pulse voltage having an amplitude corresponding to the load voltage, and generating the generated load voltage signal. A load voltage monitoring circuit superimposed on the secondary winding of the output transformer; and a load voltage signal detection circuit disposed on the first unit side for detecting the load voltage signal from the primary winding of the output transformer. A circuit for generating a control pulse, which is disposed on the first unit side and is pulse-width modulated by a detection signal from the load voltage signal detection circuit, and performs a PWM control of an ON period of the switching element of the power supply circuit; And a width modulation circuit.

According to the first aspect of the present invention, there is provided a non-contact power supply device for transmitting power between a first unit and a second unit, wherein the primary winding has a first winding. An output transformer disposed on the unit side and having a secondary winding disposed on the second unit side; and a switching element disposed on the first unit side and including a switching element for converting DC power from a DC power supply into AC power. And a power receiving circuit disposed on the second unit side for converting AC power supplied from the secondary winding of the output transformer into DC power and supplying the DC power to the load. Monitoring a load voltage appearing at both ends of the load, generating a load voltage signal composed of a pulse-like voltage having an amplitude corresponding to the load voltage, and outputting the generated load voltage signal to an output transformer. Superimposed on the secondary winding of A load voltage monitoring circuit, a load voltage signal detection circuit disposed on the first unit side for detecting a load voltage signal from the primary winding of the output transformer, and a load voltage signal detection circuit disposed on the first unit side And a pulse width modulation circuit that generates a pulse width-modulated control pulse with a detection signal from the power supply circuit and performs PWM control of the ON period of the switching element of the power supply circuit. If it is within, it can respond to any load and is efficient. In addition, the efficiency is good because the power loss under heavy load is reduced. Further, since the power is small and the heat generation is suppressed, the reliability can be improved.

According to a second aspect of the present invention, there is provided a power / signal transmission apparatus for transmitting power and a signal between a first unit and a second unit. And a bidirectional optical communication circuit having a light emitting unit and a light receiving unit for optical communication on the first unit side and the second unit side, respectively, via the bidirectional optical communication circuit. A communication device for transmitting the signal, wherein the communication device stabilizes an output voltage on the secondary side in the non-contact power supply device via the light emitting unit and the light receiving unit when the non-contact power supply device is abnormal. Power / signal transmission apparatus characterized in that the power / signal transmission apparatus is configured to transmit a feedback signal that returns to the primary side in order to realize the conversion.

According to the second aspect of the present invention, the power / signal transmission device is a power / signal transmission device for transmitting power and a signal between the first unit and the second unit. , And a bidirectional optical communication circuit having a light emitting unit and a light receiving unit for optical communication on the first unit side and the second unit side, respectively, and transmitting signals via the bidirectional optical communication circuit. The communication device includes a light emitting unit and a light receiving unit, which are connected to the primary side in order to stabilize the output voltage on the secondary side of the non-contact power supply device when the non-contact power supply device is abnormal. Since it is configured to transmit a feedback signal that returns, stable control is always possible, and reliability can be improved. In addition, power loss at the time of heavy load is reduced, whereby heat generation of circuit elements can be suppressed, and reliability can be improved. Further, the reliability and stability can be improved by the two-system feedback system for normal operation and abnormal operation.

According to a third aspect of the present invention, there is provided a power / signal transmission apparatus, comprising:
A / D which is arranged on the side of the unit and converts the output voltage monitoring signal on the secondary side into a digital signal and serves as the feedback signal
The communication device further includes a conversion unit, wherein the communication device includes: a first communication control circuit disposed on the first unit side;
Further comprising a second communication control circuit disposed on the side of the unit, wherein the first communication control circuit and the second communication control circuit communicate with each other by digital communication via the bidirectional optical communication circuit. While transmitting the signal in,
3. The power / signal transmission apparatus according to claim 2, wherein the feedback signal converted into the digital signal is fed back using an available channel other than the predetermined channel.

According to the third aspect of the present invention, the power / signal transmission device is disposed on the second unit side, and converts the output voltage monitoring signal on the secondary side into a digital signal to be a feedback signal. The communication device further includes a D conversion unit, and the communication device further includes a first communication control circuit disposed on the first unit side, and a second communication control circuit disposed on the second unit side. The communication control circuit and the second communication control circuit transmit the signal on a predetermined channel by digital communication via a bidirectional optical communication circuit, and transmit the feedback signal converted to the digital signal to a signal other than the predetermined channel. Therefore, the number of parts can be reduced by using an available channel for digital communication.

The invention according to a fourth aspect of the present invention has been made to solve the above-mentioned problem. According to a fourth aspect of the present invention, a feedback signal transmitted through the communication device is converted into an analog voltage signal by the first unit. 4. The power / signal transmission device according to claim 3, further comprising a D / A conversion circuit for controlling the next side.

According to the fourth aspect of the present invention, a D which is disposed on the first unit side and converts the feedback signal transmitted via the communication device into an analog voltage signal to control the primary side.
Since the A / A conversion circuit is further included, stable power control is possible.

According to a fifth aspect of the present invention, the first unit is a vehicle body, and the second unit is a steering wheel. 5. The power / signal transmission device according to any one of items 1 to 4.

According to the fifth aspect of the present invention, since the first unit is a vehicle body and the second unit is a steering wheel, transmission of power / signal between the vehicle body and the steering wheel is not performed. Can be done by contact.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a contactless power supply device according to the present invention. Note that, here, the non-contact power supply device is mounted on a vehicle and transmits electric power between a vehicle body (body) as a first unit and a handle portion as a second unit in a non-contact manner. A description will be given of the case where the present invention is applied.

In FIG. 1, a non-contact power supply includes a DC power supply 101, a power supply circuit 10 provided on a first unit side.
2. The pulse width modulation circuit 111, the load voltage signal detection circuit 123, and the power receiving circuit 1 provided on the second unit side.
04, a switching power supply that transmits power in a non-contact manner by the output transformer 103 between the load voltage monitoring circuit 122 and the load 112.

DC power supply 101 is, for example, a battery mounted on a vehicle. The power supply circuit 102 includes a switching element (not shown) such as a MOSFET connected to the primary winding of the output transformer 103, and switches this switching element with a pulse from the pulse width modulation circuit 111. AC power is transmitted to the power receiving circuit 104 of the second unit by electromagnetic induction of the secondary winding and the secondary winding.

In the output transformer 103, for example, a primary winding is arranged on a fixed column on the vehicle body side, a secondary winding is arranged on a steering shaft of a steering wheel, and both windings are relatively rotatable. Is a rotary transformer configured as described above.

The power receiving circuit 104 converts AC power transmitted in a contactless manner from the power supply circuit 102 via the output transformer 103 into DC power by rectifying means (not shown).
The DC power is supplied to the load 112.

The load voltage monitoring circuit 122 monitors a load voltage appearing across the load 112, and generates a load voltage signal composed of a pulse voltage having an amplitude corresponding to the load voltage.
This is for superimposing the generated load voltage signal on the secondary winding of the output transformer 103.

The load voltage signal detection circuit 123 is a load voltage monitoring circuit 1 superimposed on the secondary winding of the output transformer 103.
22 is detected from the primary winding side of the output transformer 103, and the pulse width modulation circuit 11
1 is to be controlled.

In the above configuration, the load voltage monitoring circuit 1
22 generates a load voltage signal composed of a pulse-like voltage having an amplitude corresponding to the load voltage appearing at both ends of the load 112, and transmitting power to the secondary winding of the output transformer 103 as shown in FIG. For each period not performed, it is superimposed on the secondary winding. That is, in FIG.
AC power received by the secondary winding of No. 3
Pulse-like voltage a by turning on and off the switching element
And the load voltage signal b as a feedback voltage waveform is superimposed in a form inserted between the pulsed voltages a.

Thus, the load voltage signal is transmitted from the secondary winding of the output transformer 103 to the primary winding on the first unit side. The transmitted load voltage signal is shown in FIG.
As shown in (B), the load voltage signal is detected by the load voltage signal detection circuit 123 as a feedback voltage waveform b ', and the detection signal is supplied to the pulse width modulation circuit 111, and the amplitude of the pulse voltage corresponds to the set load voltage. To be a value,
PWM (pulse width modulation) by the pulse width modulation circuit 111
Control is performed, and as a result, the load voltage can be made constant.

As described above, according to the non-contact power supply of the present invention, since the pulse width control corresponding to the load is performed, any load within the rated power can be handled, and the efficiency is high. In addition, the efficiency is good because the power loss under heavy load is reduced. Further, since the power is small and the heat generation is suppressed, the reliability can be improved.

Next, FIG. 3 is a block diagram showing an embodiment of a power / signal transmission device using the above-mentioned non-contact power supply device. Note that the same components as those of the first embodiment shown in FIG.

In FIG. 3, a power / signal transmission apparatus includes a DC power supply 101, a power supply circuit 102, a pulse width modulation circuit 111, a load voltage signal detection circuit 123, a communication control circuit 109, / A conversion circuit 110
And a switch circuit 113, a power receiving circuit 104, a load 112, a microcomputer (microcomputer) 124, a load voltage signal generating circuit 12 provided on the second unit side.
5, between the communication control circuit 107 and the indicator 114, the output transformer 103 and the bidirectional optical communication circuit 10;
8 for transmitting power and signals in a contactless manner.

Here, the DC power supply 101, the power supply circuit 102, and the pulse width modulation circuit 11 provided on the first unit side
1 and a load voltage signal detection circuit 123, a power receiving circuit 104 provided on the second unit side, a microcomputer 124, a load voltage signal generation circuit 125, and an output transformer 103.
Thus, a switching power supply device is configured. The microcomputer 124 and the load voltage signal generation circuit 125
Corresponds to the load voltage monitoring circuit 122 in FIG.

The communication control circuit 109 and the switch circuit 113 provided on the first unit side, the communication control circuit 107 and the indicator 114 provided on the second unit side, and the bidirectional optical communication circuit 108 , A communication device.

FIG. 4 is a block diagram showing a configuration example of the bidirectional optical communication circuit 108 and the communication control circuits 107 and 109.

The bidirectional optical communication circuit 108 includes a light emitting circuit 108a, a light emitting unit 108b,
A light receiving unit 108c and a light receiving circuit 108d; a light emitting circuit 108e and a light emitting unit 108 arranged on the second unit side;
f, a light receiving unit 108g and a light receiving circuit 108h.

The communication control circuit 107 is constituted by a microcomputer or the like, and includes a parallel / serial converter 107a and a gain controller 107b. The parallel / serial conversion unit 107a converts a parallel input signal (including a digital signal from the A / D conversion circuit 106) input from the second unit into a serial output signal, and performs bidirectional optical communication. The signal is supplied to the light emitting circuit 108e of the circuit 108, and the serial output signal from the light receiving circuit 108h of the bidirectional optical communication circuit 108 is supplied to the gain control unit 1
07b, and supplied to the second unit as a parallel output signal (including an output signal for driving the indicator 114).

Similarly, the communication control circuit 109 includes a microcomputer or the like, and includes a parallel / serial conversion unit 109a,
And a gain control unit 109b. The parallel / serial converter 109a converts a parallel input signal (including a switch ON signal from the switch circuit 113) input from the first unit into a serial output signal, and converts the input signal into a serial output signal. Light emitting circuit 108a
And a serial output signal from the light receiving circuit 108d of the bidirectional optical communication circuit 108 is input via the gain control unit 109b, and is output to the first unit side in a parallel output signal (D / A conversion). (Including a digital signal input to the circuit 110).

In the above-described configuration, the communication control circuit 109 disposed on the first unit side and the communication control circuit 107 disposed on the second unit side perform various operations via the bidirectional optical communication circuit 108. Signals can be transmitted to each other without contact.

The communication control circuit 109 includes the switch circuit 1
When the switch 13 is connected and a switch ON signal is input from the switch circuit 113, the communication control circuit 109 transmits the switch ON signal through the bidirectional optical communication circuit 108 using a predetermined channel of digital communication. The signal is transmitted to the control circuit 107, and the communication control circuit 107 controls the indicator 114 to light based on the received switch ON signal. Indicator 114 may be, for example,
A switch circuit 1 composed of an LED (light emitting diode) or the like
The light is turned on by the operation of No. 13 and serves as an abnormality alarm means for notifying any abnormality.

On the other hand, the power supply circuit 102 disposed on the first unit side and the power receiving circuit 104 disposed on the second unit side can transmit electric power through the output transformer 103 in a non-contact manner. it can.

The microcomputer 124 receives the output voltage of the power receiving circuit 104 and monitors the state in real time.
The microcomputer 124 supplies a monitoring signal according to the monitored output voltage state to the load voltage signal generating circuit 125, and the load voltage signal generating circuit 125 responds accordingly to the output of the power receiving circuit 104 which varies depending on the load of the load 112. A load voltage signal composed of a pulse-like voltage having an amplitude corresponding to the voltage value is generated, and as shown in FIG. 5A, the secondary winding is generated at each period when power is not transmitted to the secondary winding of the output transformer 103. Superimpose on line. That is, in FIG.
AC power received by the secondary winding of No. 3
Pulse-like voltage a by turning on and off the switching element
And the load voltage signal b as a feedback voltage waveform is superimposed in a form inserted between the pulsed voltages a.

Accordingly, the load voltage signal is transmitted from the secondary winding of the output transformer 103 to the primary winding on the first unit side. The transmitted load voltage signal is shown in FIG.
As shown in (B), the load voltage signal detection circuit 123 detects the feedback voltage waveform b '. In accordance with the detected voltage signal level, the pulse width modulation circuit 111 modulates the pulse width for switching the switching element of the power supply circuit 102, performs PWM control on the on-period of the switching element, and stabilizes the output voltage of the power receiving circuit 104. Voltage can be applied.

If the above-described constant voltage control becomes unstable or impossible due to the noise of the voltage signal, the failure of the load voltage signal generation circuit 125 or the load voltage signal detection circuit 123, etc. On the unit side, the output voltage of the power receiving circuit 104 greatly differs from the set voltage.

In this case, the microcomputer 124 detects an abnormality in the output voltage of the power receiving circuit 104, A / D converts a monitoring signal corresponding to the monitored output voltage state, and converts the monitoring signal into a digital signal to the communication control circuit 107. Supply.

The communication control circuit 107 transmits the digital signal from the microcomputer 124 through the bidirectional optical communication circuit 108 using an unused channel other than the predetermined channel for transmitting the above-mentioned signal such as the switch ON signal. To the communication control circuit 109 of the first unit. The digital signal received by the communication control circuit 109 is supplied to a D / A conversion circuit 110, where it is converted into an analog signal.

The converted analog signal is supplied to the power receiving circuit 10
4 is a signal that changes according to the output voltage value of No. 4 and is input to the pulse width modulation circuit 111. Pulse width modulation circuit 111
The pulse width for switching the switching element of the power supply circuit 102 is modulated by the input analog signal, and the output voltage of the power receiving circuit 104 is stabilized by PWM-controlling the ON period of the switching element.

As described above, in the non-contact power transmission via the output transformer 103, the feedback signal for stabilizing the output voltage on the second unit side normally passes through the output transformer 103, but when an abnormality occurs, Communication control circuits 107 and 109 for transmitting signals in a non-contact manner without passing through output transformer 103 and bidirectional optical communication circuit 1
Since the signal is transmitted to the first unit side using the free channel of the digital communication in 08, stable control is always possible and reliability can be improved. Also, the power loss under heavy load is reduced,
Heat generation of the circuit element can be suppressed, and reliability can be improved. Further, the reliability and stability can be improved by the two-system feedback system for normal operation and abnormal operation.

As described above, the embodiment of the present invention has been described. However, the present invention is not limited to this, and various modifications and applications are possible.

For example, in the above-described embodiment, the present invention is applied to the non-contact transmission of electric power and signals between a vehicle body (body) as a first unit and a steering wheel as a second unit. However, the present invention is not limited to this, and can be applied to, for example, non-contact power / signal transmission between a vehicle body and a sliding door in a vehicle as a whole. It is also applicable to wireless power and signal transmission in the field.

[0046]

According to the first aspect of the present invention, since the pulse width control corresponding to the load is performed, any load within the rated power can be handled, and the efficiency is high. Also,
Since the power loss under heavy load is reduced, efficiency is high. Further, since the power is small and the heat generation is suppressed, the reliability can be improved.

According to the second aspect of the present invention, stable control is always possible, and reliability can be improved. In addition, power loss at the time of heavy load is reduced, whereby heat generation of circuit elements can be suppressed, and reliability can be improved. Further, the reliability and stability can be improved by the two-system feedback system for normal operation and abnormal operation.

According to the third aspect of the present invention, the number of parts can be reduced by using an available channel for digital communication.

According to the fourth aspect of the present invention, stable power control becomes possible.

According to the fifth aspect of the present invention, the transmission of power and signals between the vehicle body and the steering wheel can be performed in a non-contact manner.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a contactless power supply device according to the present invention.

FIGS. 2A and 2B are signal waveform diagrams of respective units in the non-contact power supply device of FIG. 1, respectively.

FIG. 3 is a block diagram showing an embodiment of a power / signal transmission device according to the present invention.

FIG. 4 is a block diagram illustrating a configuration example of a bidirectional optical communication circuit and a communication control circuit in the power / signal transmission device of FIG. 3;

FIGS. 5A and 5B are signal waveform diagrams of respective units in the power / signal transmission device of FIG. 3;

FIG. 6 is a block diagram illustrating a configuration example of a conventional power transmission device.

[Explanation of symbols]

101 DC power supply 102 Power supply circuit 103 output transformer 104 Power receiving circuit 107 communication control circuit (second communication control circuit) 108 Bidirectional optical communication circuit 108b, 108f Light emitting unit 108c, 108g Light receiving unit 109 communication control circuit (first communication control circuit) 110 D / A conversion circuit 111 pulse width modulation circuit 112 load 113 switch circuit 114 Indicator 122 Load voltage monitoring circuit 123 Load voltage signal detection circuit 124 microcomputer (A / D conversion means) 125 Load voltage signal generation circuit

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Junya Tanikawa             1500 Yajuku Sogyo Co., Ltd.             Inside (72) Inventor Hiromitsu Inoue             1500 Yajuku Sogyo Co., Ltd.             Inside F-term (reference) 5H730 AA12 AA14 AA17 AS01 BB21                       BB57 DD04 EE01 FD01 FD21                       FF09 FF19 FG05 FG07

Claims (5)

[Claims] 1. A non-contact power supply device for transmitting power between a first unit and a second unit, wherein a primary winding is disposed on the first unit side and a secondary winding is disposed on the first unit. An output transformer disposed on the second unit side; and a switching element disposed on the first unit side, including a switching element, converting DC power from a DC power supply into AC power, and converting the DC power from the DC power into the primary winding of the output transformer. A power supply circuit to be supplied, a power receiving circuit arranged on the second unit side, converting AC power supplied from the secondary winding of the output transformer to DC power, and supplying the DC power to a load; It monitors the load voltage appearing at both ends of the load, generates a load voltage signal composed of a pulse-like voltage having an amplitude corresponding to the load voltage, and outputs the generated load voltage signal to the output transformer. For the next winding A load voltage monitoring circuit to be folded; a load voltage signal detection circuit disposed on the first unit side for detecting the load voltage signal from the primary winding of the output transformer; and a load voltage signal detection circuit disposed on the first unit side And a pulse width modulation circuit that generates a pulse width modulated control pulse with a detection signal from the load voltage signal detection circuit and performs PWM control on the ON period of the switching element of the power supply circuit. Contactless power supply. 2. A power / signal transmission device for transmitting power and a signal between a first unit and a second unit, wherein the non-contact power supply device according to claim 1; A communication device that includes a bidirectional optical communication circuit having a light emitting unit and a light receiving unit for optical communication on the second unit side, and that transmits the signal via the bidirectional optical communication circuit; The device transmits, via the light emitting unit and the light receiving unit, a feedback signal that returns to the primary side to stabilize the output voltage on the secondary side of the non-contact power supply device when the non-contact power supply device is abnormal. A power / signal transmission device characterized by being configured to perform the following. 3. The power / signal transmission device according to claim 1, wherein the power / signal transmission device includes an A / D converter configured to convert the output voltage monitoring signal on the secondary side into a digital signal and use the output signal as the feedback signal. The communication device further includes a first communication control circuit disposed on the first unit side, and a second communication control circuit disposed on the second unit side. The communication control circuit and the second communication control circuit,
Through the bidirectional optical communication circuit, while transmitting the signal in a predetermined channel by digital communication, and the feedback signal converted into the digital signal is returned using an available channel other than the predetermined channel. The power / signal transmission device according to claim 2, wherein: 4. A D / A conversion circuit disposed on the first unit side, the D / A conversion circuit converting a feedback signal transmitted via the communication device into an analog voltage signal to control a primary side. The power / signal transmission device according to claim 3, wherein: 5. The power / signal transmission device according to claim 2, wherein the first unit is a vehicle body, and the second unit is a handle. .