JP2003333850A - Voltage regulator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a voltage regulator for controlling the power consumption of a load apparatus by lowering a power supply voltage in which the distortion of a waveform is suppressed, no contact is present between an input power supply and the load apparatus and noise is reduced. <P>SOLUTION: The voltage regulator 1 comprises a reactor 2 connected with an AC line, a winding 3 for regulating the inductance of the reactor 2, and a phase control circuit 4, and is connected with the load apparatus 5. The inductance regulation winding 3 has a minimum output voltage at the time of a full angle OFF in the phase control circuit. When the phase control circuit is 100% ON, the inductance becomes 0 and the output voltage has a maximum value. The inductance of the reactor 2 is varied continuously by phase control (conduction angle). A voltage detecting circuit for detecting the voltage of the load apparatus can provide a voltage regulator for making constant the output voltage regardless of a variation of in input voltage. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

In the case of the auto-transformer type, a reactor having a secondary winding is inserted in series on the common side of a transformer whose turn ratio is set so that the output voltage is at the minimum position.
When the secondary winding of this reactor is short-circuited by phase control, the impedance of the reactor changes steplessly from 0 to the maximum depending on the degree of control, and the impedance on the common side of the autotransformer changes accordingly and the load The voltage supplied to can be adjusted steplessly. In the case of a reactor, by adjusting the degree of short circuit of the secondary winding by phase control in a reactor having a secondary winding, the impedance of the reactor itself is controlled and the voltage drop can be adjusted steplessly and supplied to the load. Control the voltage applied.

TECHNICAL FIELD OF THE INVENTION

The present invention is a voltage regulator for adjusting the voltage of a load device by lowering the power supply voltage, and a voltage regulator for controlling power consumption.

[Prior art]

In FIG. 3, an autotransformer is connected to the AC electric line, the taps are switched, the output voltage is changed, and the load device is supplied. Fig. 4 shows that the reactor is inserted in the AC circuit,
By utilizing the voltage drop due to the impedance, the change amount of the output voltage is supplied to the load device. At this time, the output voltage was controlled by changing the impedance by switching the taps. A contactless switch or a contactless switch such as a thyristor switch SCR has been used as a means for switching these taps.

[Problems to be Solved by the Invention]

In the case of the tap switching system, there is a drawback that the output voltage cannot be adjusted steplessly due to the steps.

Further, when taps are short-circuited when taps are switched, a large current flows through the coil, and there is a risk of burning.
Since it must be connected after opening, switching noise is generated and there is a great risk that load devices will be adversely affected.

FIG. 5 is a circuit in which the drawback of the tap type is improved, and is designed so that the output voltage can be adjusted steplessly. However, the inductance component of the saturable reactor is adjusted by the DC power supply. Therefore, when the control transformer is excited only in one direction and controls one of the first, fourth, or second and third quadrants, the other quadrant cannot be controlled. Therefore, even if a small amount of output voltage can be adjusted, controlling the voltage drop of 20 to 50% will disturb the waveform balance, which is not suitable for practical use. In addition, it is necessary to separately prepare a DC power source for control.

[Means for Solving the Problems]

In order to solve the above problems of the conventional voltage regulator, the present invention can adjust the output voltage of the autotransformer or the reactor steplessly, and requires another special power source for the circuit required for the adjustment. The present invention provides a voltage regulator which does not include a control reactor having an autotransformer and a secondary winding (Fig. 2), or a reactor having a secondary winding (Fig. 1) and a bidirectional phase control circuit for controlling an output voltage. It is to have. In the voltage regulator, the phase control circuit is provided with a voltage detection circuit that detects the voltage of the load.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a reactor type embodiment of the voltage regulator according to the present invention. The present invention will be described below with reference to the drawings.

The voltage regulator 1 comprises a reactor 2 connected to an AC line, a winding 3 for adjusting the inductance component of the reactor 2 and a circuit 4 for phase control.
It is connected to the load device 5.

When the current flowing through the load is I, the voltage drop due to the reactor is V = 2πfL × I, and the output voltage is the remaining voltage obtained by subtracting V from the input voltage E.
At this time, the inductance adjusting winding 3 is in the full-angle OFF state in the phase control circuit, and at this time, the output voltage becomes the minimum value.

When the phase control circuit is 100% ON, a current flowing in the reactor 2 causes a current induced in the secondary winding 3 to generate a voltage in a phase opposite to the voltage of the reactor 2 and cancel each other out. , The inductance becomes 0,
No voltage drop occurs. That is, the load device operates at the input voltage, and the output voltage becomes the maximum value in the full-angle ON state in this phase control circuit.

The inductance of the reactor 2 is adjusted by the phase control (conduction angle), and the output voltage is continuously variable.

FIG. 2 shows an auto-transformer embodiment of the voltage regulator according to the present invention. The present invention will be described based on the following drawings.

The voltage regulator 6 is composed of an auto transformer 7 connected to an AC electric path, a reactor 8 for adjusting a voltage, and a phase control circuit 9 for adjusting an inductance component of the reactor 8, and a load device 10 is provided. It is connected to the.

The adjustment operation is the difference that the inductance on the common side of the autotransformer is adjusted by utilizing the saturation of the reactor. However, the characteristics differ between the reactor type and the autotransformer type as follows. is there.

In the case of the reactor type, the voltage drop is determined by the product of the inductance component of the reactor and the current flowing therethrough, and the voltage applied to the load fluctuates due to the fluctuation of the load. Is not suitable. However, by setting the amount of voltage drop in the control circuit, an inductive load (fan motor, etc.) has a small inductance when the current is large (eg a large fan motor) and a large inductance when the current is small (eg a small fan motor).
And an inductance amount matching the L component of the load can be set proportionally, which is optimal for an inductive load with a small load fluctuation.

On the other hand, in the transformer type, since the output voltage is fixed regardless of the size of the load, there is no change in the output voltage due to the change in the load. However, inductive load (fan motor, etc.)
Irrespective of the magnitude of, if the inductance of the transformer inserted in the AC circuit is large, the load may be affected, the power factor may change significantly, and the power saving effect may be diminished. Optimal when the load fluctuates and is relatively small.

[0018]

As described above, in the voltage regulator according to the present invention, in the voltage regulator that controls the power consumption of the load device by lowering the power source voltage, the phase that supplies the voltage in the opposite phase to the power source voltage. By providing the control circuit, the output voltage can be adjusted steplessly and the primary side is not directly switched by the thyristor SCR or the like, so there is no time when the voltage is 0 with respect to the load, and the voltage fluctuation is at the maximum voltage drop, that is, The effect is that the output voltage goes up and down between the minimum value and the set output voltage, the distortion of the waveform is small, there is no contact point between the input power supply and the load device, and the generation of noise is minimal.
Further, by providing a voltage detection circuit for detecting the voltage of the load device in the voltage regulator, it is possible to provide a constant voltage output type voltage regulator that keeps the output voltage constant regardless of the fluctuation of the input voltage. .

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a reactor formula of the present invention.

FIG. 2 is a circuit diagram showing an autotransformer of the present invention.

FIG. 3 is a circuit diagram showing an auto transformer tap control.

FIG. 4 is a circuit diagram showing reactor type tap control.

FIG. 5 is a circuit diagram showing an auto-transformer DC power supply control.

[Explanation of symbols]

1 voltage regulator 2 reactor 3 windings 4 Phase control circuit 5 load 6 voltage regulator 7 Auto transformer 8 reactor 9 Phase control circuit 10 load

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[Procedure amendment]

[Submission date] August 6, 2002 (2002.8.6)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a reactor formula of the present invention.

FIG. 2 is a circuit diagram showing an autotransformer of the present invention.

FIG. 3 is a circuit diagram showing an auto transformer tap control.

FIG. 4 is a circuit diagram showing reactor type tap control.

FIG. 5 is a circuit diagram showing an auto-transformer DC power supply control.

FIG. 6 is a diagram showing a conduction angle of phase control.

[Explanation of symbols] 1 voltage regulator 2 reactor 3 windings 4 Phase control circuit 5 load 6 voltage regulator 7 reactor 8 windings 9 Phase control circuit 10 load

Claims (2)

[Claims] 1. A single-phase circuit and a three-phase circuit connected to an AC circuit are provided with a bidirectional phase control device for steplessly adjusting the output voltage on the secondary side of an autotransformer type and a reactor type. Characteristic voltage regulator. 2. The voltage regulator according to claim 1, further comprising a voltage detection circuit for detecting a voltage of a load device, which is of a constant voltage output type with respect to the load.