JP2007151299A - Non-contact type feeder system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a non-contact type feeder system capable of attaining stable non-contact feeding by suppressing self heat generation of a supersaturated reactor and a transient voltage change due to a temperature change, thus producing a voltage under an allowable upper limit to be supplied to a load. <P>SOLUTION: This feeder system includes a receiver circuit for receiving electric power from ground equipment; a rectifier circuit for rectifying a received AC current; a voltage smoothing circuit for suppressing voltage fluctuations; a voltage detection circuit for detecting a voltage of the voltage smoothing circuit; and a current control circuit for interrupting a current from the rectifier circuit to the voltage smoothing circuit in response to a signal from the voltage detection circuit. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a non-contact power supply device, and more particularly to a non-contact power supply device that can stably supply power to a load at a voltage below an allowable upper limit by suppressing a peak voltage.

The non-contact power feeding device is used, for example, in a transport device such as a tracked unmanned transport cart. As a power feeding device that feeds power to the transport device in a non-contact manner, a power receiving coil in which a coil is wound around the center leg portion of an E-shaped core is arranged on two rows of power wires laid in parallel at a certain distance from the floor surface. There has been proposed a non-contact power feeding apparatus that transmits power by inducing a magnetic field generated by a high-frequency current flowing through a power feeding line to a power receiving coil.
In this non-contact power feeding device, the secondary circuit of the receiving coil has a resonance capacitor and a saturable reactor connected in parallel to the receiving coil, and the resonance circuit voltage rises to a value at which the core of the saturable reactor is magnetically saturated. When the saturates, the core relative magnetic permeability suddenly decreases from a value inherent to the magnetic material of the core (approximately 2000 to 4000) to approximately 1, and the inductance of the saturable reactor also decreases in proportion to the relative magnetic permeability. The saturable reactor has an inductance of several tens of mH with respect to the winding resistance (approximately 1Ω or less) in a region where it is not saturated, and the current phase is delayed by approximately 90 degrees with respect to the voltage phase. As a result, in one cycle of high-frequency alternating current, a saturation current flows through the saturable reactor when the voltage is near zero, thereby short-circuiting the resonance circuit. This suppresses the no-load voltage of the resonance circuit, and also suppresses the reactive current flowing through the no-load resonance circuit.

By the way, the saturation magnetic flux density of the saturable reactor is a specific value determined by the material characteristics. Generally, in the case of a ferrite material, the saturation magnetic flux density has a negative temperature coefficient and rises to about 80 to 100 ° C. due to self-heating. Decreases by around 20%. For this reason, when the voltage is stabilized only by the saturable reactor, it is necessary to set the saturation voltage in consideration of the temperature characteristics.
In addition, considering the upper limit of the fluctuation range that cannot follow the transiently changing primary current, even if a transient primary current occurs immediately after starting the device at a low temperature, the allowable upper limit of the voltage supplied to the load Must be set below the voltage. For this reason, the load supply voltage in a state where the apparatus is continuously used and the temperature is stabilized by self-heating may be lower than the optimum voltage supplied to the load.

  In other words, the ferrite core used for the saturable reactor changes the magnetic flux density at which it is magnetically saturated depending on the operating temperature, so it must be installed in consideration of cooling so that no significant temperature changes occur due to ambient temperature changes or self-heating. There was a problem of becoming.

  In view of the problems of the conventional non-contact power feeding device described above, the present invention suppresses a transient voltage change due to a self-heating of the saturable reactor and a temperature change, so that the voltage supplied to the load is lower than an allowable upper limit voltage. It is an object of the present invention to provide a non-contact power feeding device that can perform stable and non-contact power feeding.

  In order to achieve the above object, a contactless power supply device according to the first aspect of the present invention is a contactless power supply device that supplies power from a ground facility to a moving body by electromagnetic induction in a contactless manner, and receives power from the ground facility. Circuit, rectifier circuit for rectifying received AC current, voltage smoothing circuit for suppressing voltage fluctuation, voltage detection circuit for detecting voltage of voltage smoothing circuit, and voltage smoothing from rectifier circuit according to signal from voltage detection circuit And a current control circuit for intermittently supplying current to the circuit.

  In order to achieve the same object, the non-contact power feeding device of the second invention is a non-contact power feeding device that supplies power from a ground facility to a moving body by electromagnetic induction in order to receive power from the ground facility. Power receiving circuit, a rectifying circuit for rectifying the received AC current, a voltage detecting circuit for detecting the voltage before voltage smoothing rectified by the rectifying circuit, a voltage smoothing circuit for suppressing voltage fluctuation, and a voltage detecting circuit And a current control circuit for intermittently passing a current from the rectifier circuit to the voltage smoothing circuit according to the signal.

  According to the contactless power supply device of the first aspect of the present invention, in the contactless power supply device that supplies power from the ground facility to the moving body by electromagnetic induction in a contactless manner, the power receiving circuit for receiving power from the ground facility and the power received A rectifier circuit that rectifies alternating current, a voltage smoothing circuit that suppresses voltage fluctuations, a voltage detection circuit that detects the voltage of the voltage smoothing circuit, and a current from the rectifier circuit to the voltage smoothing circuit according to a signal from the voltage detection circuit Current control circuit to be intermittently provided, the current control circuit can feedback control the current from the rectifier circuit to the voltage smoothing circuit according to the voltage value preset in the voltage detection circuit. The supplied voltage is suppressed below the upper limit voltage allowed by the device, and the reactive current at no load is suppressed by the saturable reactor. Feeding can be performed, in particular, without the load voltage increases too much even in a transient state as the voltage at a few cycles of a high frequency power source changes suddenly, the equipment load can be stably operated.

  The contactless power supply device according to the second aspect of the present invention is a contactless power supply device that supplies power from a ground facility to a moving body by electromagnetic induction in a contactless manner, and a power receiving circuit for receiving power from the ground facility, A rectifier circuit that rectifies an alternating current, a voltage detection circuit that detects a voltage that has been rectified by the rectifier circuit and that has not been smoothed, a voltage smoothing circuit that suppresses voltage fluctuations, and a rectifier circuit that responds to a signal from the voltage detection circuit Current control circuit for intermittently passing the current from the voltage smoothing circuit to the voltage smoothing circuit, the current control circuit controls the current from the rectifier circuit to the voltage smoothing circuit according to the voltage value preset in the voltage detection circuit. As a result, the voltage supplied to the load is suppressed below the upper limit voltage allowed by the device, and the reactive current at no load is suppressed by the saturable reactor, from no load to full load. Efficient contactless power supply in the region of the load, especially in the transient state where the voltage changes suddenly in several cycles of the high-frequency power supply, the load voltage does not rise too much, and the load equipment can be operated stably Can do.

  Embodiments of a non-contact power feeding device according to the present invention will be described below with reference to the drawings.

FIG. 1 shows a first embodiment of the non-contact power feeding device of the present invention.
This non-contact power supply device supplies electric power from a ground facility to a moving body such as a transport vehicle by electromagnetic induction in a non-contact manner, and rectifies a received AC circuit for receiving power from the ground facility and a received AC current. A rectifier circuit, a voltage smoothing circuit that suppresses voltage fluctuation, a voltage detection circuit that detects the voltage of the voltage smoothing circuit, and a current control circuit that interrupts current from the rectifier circuit to the voltage smoothing circuit according to a signal from the voltage detection circuit And.

  In addition, this non-contact power feeding device regards the purpose of providing a saturable reactor as secondary voltage stabilization and is provided in parallel with the resonant circuit to suppress the current of the resonant circuit at no load. The transient voltage change due to the self-heating of the saturated reactor or temperature change is controlled by intermittently controlling the current after rectifying the receiving coil generated voltage by the load supply voltage value, thereby suppressing the peak voltage and allowing the voltage supplied to the load Stable non-contact power feeding is performed at a voltage lower than the upper limit.

In FIG. 1, reference numeral 1 denotes a power receiving coil, and the power receiving coil 1 is installed so as to straddle a power supply line 2 laid in parallel.
The feeder line 2 is connected to a high frequency power supply device (not shown), and a high frequency current of about 10 kHz is supplied from the high frequency power supply device.
The power receiving circuit includes a power receiving coil 1, a resonant capacitor 3 that forms a resonant circuit, and a saturable reactor 4. A rectifying element 5 is connected to the output of the power receiving circuit as a rectifying circuit, and the output of the power receiving circuit is rectified. I am doing so.

Further, on the output side of the rectifying element 5, a current control circuit including an FET 6, a Zener diode 8, a diode 9 and a photocoupler 13 is provided. This current control circuit includes a subsequent voltage detection circuit including an FET 7. An overload voltage signal is sent.
The current control circuit performs control so that the current is interrupted by an excessive load voltage signal from the load voltage detection circuit.
The voltage smoothing circuit is connected so that the output of the FET 6 of the current control circuit is smoothed by the inductance 10 and the smoothing capacitor 11 and supplied to the load 12.

Here, when the voltage value of the voltage smoothing circuit exceeds the voltage value preset in the voltage detection circuit, an overvoltage signal is immediately sent from the voltage detection circuit to the current control circuit.
The current control circuit turns off the current from the rectifier circuit to the voltage smoothing circuit, and supplies the power stored in the smoothing capacitor 11 in the voltage smoothing circuit to the load.
When the power stored in the smoothing capacitor 11 decreases, the voltage of the voltage smoothing circuit decreases, so the overvoltage detection signal of the voltage detection circuit is turned OFF, and the current control circuit turns the current from the rectifier circuit to the voltage smoothing circuit again. Perform feedback control.
Thereby, the voltage supplied to the load can be stabilized at a voltage equal to or lower than an allowable upper limit.

FIG. 2 shows the output voltage of the rectifier circuit, the ON / OFF state of the output of the current control circuit, and the voltage of the voltage smoothing circuit.
The waveform in each circuit is shown, (A) is a waveform diagram at light load, and (B) is a waveform diagram at heavy load.

In this embodiment, the case where the FET (field effect transistor) is used as the switching element has been described. However, a bipolar transistor or an insulated gate transistor (IGBT) can be used instead of the bipolar transistor.
Further, although a Zener diode is used for the operating voltage of the FET 6, a constant voltage circuit such as a forward voltage of the diode can also be used.

FIG. 3 shows a second embodiment of the non-contact power feeding device of the present invention.
This non-contact power supply device supplies electric power from a ground facility to a moving body such as a transport vehicle by electromagnetic induction in a non-contact manner, and rectifies a received AC circuit for receiving power from the ground facility and a received AC current. A rectifier circuit, a voltage detection circuit that detects a voltage before smoothing the voltage rectified by the rectifier circuit, a voltage smoothing circuit that suppresses voltage fluctuation, and a rectifier circuit to a voltage smoothing circuit according to a signal from the voltage detection circuit And a current control circuit for intermittently interrupting the current.

  In addition, this non-contact power feeding device regards the purpose of providing a saturable reactor as secondary voltage stabilization and is provided in parallel with the resonant circuit to suppress the current of the resonant circuit at no load. The transient voltage change due to the self-heating of the saturated reactor and the temperature change is controlled by the voltage value after rectification, the peak voltage is suppressed by the intermittent control of the current, and the voltage supplied to the load is stabilized below the allowable upper limit voltage. Non-contact power feeding is performed.

In FIG. 3, reference numeral 1 denotes a power receiving coil, and the power receiving coil 1 is installed so as to straddle a power supply line 2 laid in parallel.
The feeder line 2 is connected to a high frequency power supply device (not shown), and a high frequency current of about 10 kHz is supplied from the high frequency power supply device.
The power receiving circuit includes a power receiving coil 1, a resonant capacitor 3 that forms a resonant circuit, and a saturable reactor 4. A rectifying element 5 is connected to the output of the power receiving circuit as a rectifying circuit, and the output of the power receiving circuit is rectified. I am doing so.

Further, a current control circuit including an FET 6, a Zener diode 8, and a diode 9 is provided on the output side of the rectifying element 5, and the current control circuit includes a load voltage excess signal from a previous voltage detection circuit including the FET 7. Will be sent.
The current control circuit performs control so that the current is interrupted by an excessive load voltage signal from the load voltage detection circuit.
The voltage smoothing circuit is connected so that the output of the FET 6 of the current control circuit is smoothed by the inductance 10 and the smoothing capacitor 11 and supplied to the load 12.

Here, when the output voltage of the rectifier circuit is equal to or higher than a voltage value preset in the voltage detection circuit, an excessive voltage signal is sent from the voltage detection circuit to the current control circuit.
When the current control circuit receives the excessive voltage signal, the current control circuit turns off the current to the voltage smoothing circuit, so that the voltage is controlled so as not to exceed the voltage value preset in the voltage detection circuit.
In addition, during the time when the current from the rectifier circuit output to the voltage smoothing circuit is turned off by the current control circuit, the power stored in the smoothing capacitor 11 in the smoothing circuit is supplied to the load, so the load is not interrupted. Power is supplied.
When the power stored in the smoothing capacitor 11 decreases, the voltage of the voltage smoothing circuit decreases, so the overvoltage detection signal of the voltage detection circuit is turned OFF, and the current control circuit turns the current from the rectifier circuit to the voltage smoothing circuit again. Control to turn on.
Thereby, the voltage supplied to the load can be stabilized at a voltage equal to or lower than an allowable upper limit.

FIG. 4 is a graph showing the relationship between the output voltage of the rectifier circuit and the load in the non-contact power feeding apparatus of the present embodiment, and shows that the output voltage of the rectifier circuit decreases as the load increases.
From this graph, using the fact that the output voltage of the rectifier circuit is determined for the load, the setting of the detection voltage of the voltage detection circuit constituted by the FET 7 of FIG. 3 is matched to the output voltage value of the rectification circuit at the maximum load. .

FIG. 5 shows the output voltage of the rectifier circuit, the ON / OFF state of the output of the current control circuit, and the voltage of the voltage smoothing circuit.
Regardless of the output voltage of the rectified circuit that has been full-wave rectified, when the output voltage setting value preset in the voltage detection circuit is exceeded, the output of the current control circuit is turned off and the smoothing circuit exceeds the output voltage setting value. It is controlled not to become voltage.
When the load is large, as shown in FIG. 4, the output voltage of the rectifier circuit decreases, so the ON time of the current control circuit is lengthened, and the voltage from the no-load state to the maximum load state may be constant. It becomes possible.

  In this embodiment, the switching element is described as using a field effect transistor (FET), but a bipolar transistor or an insulated gate transistor (IGBT) can be used instead of the bipolar transistor. Further, although a Zener diode is used for the operating voltage of the FET 6, a constant voltage circuit such as a forward voltage of the diode can also be used.

  As mentioned above, although the non-contact electric power feeder of this invention was demonstrated based on several Example, this invention is not limited to the structure described in the said Example, The structure described in each Example is combined suitably. For example, the configuration can be changed as appropriate without departing from the spirit of the invention.

  The contactless power supply device of the present invention suppresses the voltage supplied to the load below the upper limit voltage allowed by the device, and the reactive current at no load is suppressed by a saturable reactor, which is efficient in the region from no load to full load. In addition to being able to perform typical non-contact power feeding, it can be suitably used for non-contact power feeding device applications for transport devices operating in clean rooms such as semiconductor factories, and the ambient temperature is It can also be widely used as a non-contact power supply device in various manufacturing factories that change.

It is a circuit diagram showing the 1st example of the non-contact electric supply device of the present invention. The output voltage of the rectifier circuit of the same Example, the ON-OFF state of the output of a current control circuit, and the voltage of a voltage smoothing circuit are shown, (A) is a waveform diagram at the time of light load, (B) is at the time of heavy load FIG. It is a circuit diagram which shows 2nd Example of the non-contact electric power feeder of this invention. It is a graph which shows the relationship between the output voltage of the rectifier circuit of the Example, and load. The output voltage of the rectifier circuit of the same Example, the ON-OFF state of the output of a current control circuit, and the voltage of a voltage smoothing circuit are shown, (A) is a waveform diagram at the time of light load, (B) is at the time of heavy load FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power receiving coil 2 Feeding line 3 Resonance capacitor 4 Saturable reactor 5 Rectifier 6 FET (field effect transistor)
7 FET (Field Effect Transistor)
8 Zener diode 9 Diode 10 Inductance 11 Smoothing capacitor 12 Load 13 Photocoupler

Claims (2)

  In a non-contact power supply device that supplies electric power from a ground facility to a moving object by electromagnetic induction, a power receiving circuit that receives power from the ground facility, a rectifier circuit that rectifies the received AC current, and suppresses voltage fluctuations A voltage smoothing circuit, a voltage detection circuit for detecting a voltage of the voltage smoothing circuit, and a current control circuit for intermittently passing a current from the rectifier circuit to the voltage smoothing circuit in accordance with a signal from the voltage detection circuit A non-contact power feeding device.   In a non-contact power supply device that supplies electric power from a ground facility to a moving body by electromagnetic induction, a power receiving circuit for receiving power from the ground facility, a rectifier circuit that rectifies the received AC current, and a rectifier circuit Voltage detection circuit that detects a voltage before rectified voltage smoothing, a voltage smoothing circuit that suppresses voltage fluctuation, and a current control circuit that interrupts current from the rectification circuit to the voltage smoothing circuit according to a signal from the voltage detection circuit And a non-contact power feeding device.

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