JPS599295Y2 - voltage regulator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a voltage regulator that adjusts voltage based on the relationship between lagging current and leading current, and more particularly to a voltage regulator that prevents overvoltage from occurring.

By connecting a reactor in series with the AC power line, connecting a capacitor between the AC power lines on the output side of the reactor, further connecting the reactor between the AC power lines via a thyrisk switch, and controlling the conduction angle of the thyrisk switch. A method of adjusting the voltage by changing the ratio between the leading current and the lagging current is already known.

However, if the Cyrisk switch is turned off due to destruction, or if the gate signal is no longer applied to the Cynostar switch due to a failure in the control circuit, the actuator connected in series with the Cynostar switch becomes disconnected from the circuit, and the delay current becomes insufficient. The output voltage increases.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a voltage regulator that can prevent an abnormal increase in output voltage in a circuit that regulates voltage using a capacitor and an actor.

To achieve the above object, the present invention consists of an inductance circuit connected to an AC power source, a capacitor connected to the AC circuit so that a leading current flows to reduce the voltage drop in the inductance circuit, and a continuity control element. a voltage adjusting reactor connected in parallel to the capacitor; a voltage detection circuit for detecting a voltage on the output side of the inductance circuit; and a voltage detection circuit configured to adjust the voltage to a predetermined value in response to the output of the voltage detection circuit. a control circuit for controlling the conduction control element; This relates to a voltage regulator that is connected in parallel with a switch.

According to the present invention, since the actuator is connected even when voltage adjustment by the conduction control element becomes impossible, it is possible to continue supplying power while preventing abnormal voltage increases.

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

In FIG. 1 showing a charging DC power supply device according to the first embodiment of the present invention, a rectifier circuit 13 for converting AC into DC is connected between an AC power supply 11 and a storage battery load 12. .

This rectifier circuit 13 includes four diodes 14, 15,
This is a full wave rectifier circuit in which 16 and 17 are connected in a bridge type.

The first glue actor 21, which serves as a voltage drop inductance circuit, is connected in series to one of the two AC power lines 19, 20 between the AC power supply 11 and the rectifier circuit 13, and is used for voltage regulation and harmonic blocking. It is used.

The first capacitor 22 is connected between the AC power lines 19 and 20 between the output stage of the l-th reactor 21, that is, the first reactor 1-21, and the rectifier circuit 13, and is used for voltage regulation and harmonic blocking. It is used for.

A second capacitor is connected in parallel to this first capacitor 22 via thyristors 23 and 24, which are switches whose conduction angle can be controlled.
A glue actor 25 is connected.

A third glue actor 2 is provided between the rectifier circuit 13 and the load 12.
6 and a second capacitor 27 are connected to a certain smoothing circuit.

28 is a voltage detection circuit, which detects the output voltage of the rectifier circuit 13, that is, the load voltage.

29 is a thyristor control circuit, which controls thyristor control circuit 23.29 so that the output voltage becomes a predetermined value. This is a circuit that controls 24.

This thyristor control circuit 29 includes a thyristor 23. A power supply voltage detection circuit 18 is also connected to control the conduction angle of 24.

Since this control circuit 29 is a well-known thyristor conduction control circuit, detailed explanation will be omitted.

In the above-described circuit, the first glue actor 21 is not only used for voltage control but also has a harmonic current blocking function, and is a 20 mH glue actor in this embodiment.

Further, the first capacitor 22 is not only used for voltage control, but also has a harmonic current blocking function, and in this embodiment, it is 600 μF.

The second glue actor 25 is for flowing a delayed current force during voltage adjustment, and is a 20 mH glue actor in this embodiment.

In the DC power supply device of this embodiment, in addition to the above-mentioned main circuit, an overvoltage prevention reactor 30 is provided, and a pair of power lines 1
9. 20 through a switch 31.

In order to turn on the switch 31 only in the event of overvoltage, resistors 32 and 33 are connected to the voltage detection circuit 28, and the base of a transistor 34 is connected to the dividing point of the load voltage.
A Zener diode 35 is connected between the emitter of this transistor 34 and ground, and a relay coil 37 is connected between a DC power supply terminal 36 and the collector of the transistor 34.

Note that when the load voltage becomes excessive, the transistor 34 is turned on, the relay coil 37 is energized, and the switch 3 is turned on.
1 is designed to be closed.

Next, the operation of the above circuit will be explained.

If the output voltage increases for some reason while power is being supplied to the storage battery load 12 at a constant voltage, this will be detected by the voltage detection circuit 28 and the thyristor 23 . The thyristor 23,
24 is controlled by a control circuit 29.

By the way, if the voltage of the AC power supply 11 is, for example, a sine wave of 200 mm, 5 Q Hz as shown in FIG. 2A, then
Since the conduction angles of the thyristors 23 and 24 are controlled as shown in FIG. 2B, when it is desired to lower the output voltage, the control is performed so that the period t, to t2 and the period t3 to t4 become large.

Thyristor 23. If the conduction time of 24 becomes longer, the second
The lagging current flowing through the glue actor 25 increases.

A leading current I flows through the first capacitor 22 .

is flowing, so in addition to the load current, a lagging current (■1) and a leading current (I) are flowing in the first forward actuator 21.

A combined current will flow.

The voltage drop in the first glue actor 21 is a delayed current ■,
and the leading current IC, in this case the leading current ■.

Since lag current I is approximately constant, as lag current I increases, the voltage drop increases and lag current I increases.

The smaller the voltage drop, the smaller the voltage drop.

Therefore, the load voltage increases and the thyristor 23. As the conduction angle of 24 increases, the voltage drop in the l-th reactor 21 increases, and the AC voltage on the input side of the rectifier circuit and the DC voltage on its output side decrease and approach a predetermined voltage value.

When the output voltage drops below a predetermined value, the operation is completely opposite to that described above, the conduction angle of the thyristors 23 and 24 becomes small, the delay current 1 flowing to the second slope actor 25 is limited, and the delay current of? It operates so that the voltage drop decreases and the output voltage approaches a predetermined value.

By the way, the third harmonic (150H) of the fundamental wave 5Q Hz
When determining the impedance of the first reactor 21 and the impedance of the first capacitor 22 with respect to
= 18.850, and the first capacitor is 600μF
Therefore, -5=1.77Ω.

Therefore, 1/ωL=0.094, and the impedance of the circuit of the first capacitor 22 to the third harmonic is approximately one of the impedance of the circuit from the first actuator 21 and the power source 11.

Therefore, almost all of the third harmonic current flows to the first capacitor 22, thereby preventing it from flowing to the AC power supply 11 side via the first actuator 21.

Regarding the 5th harmonic (250 Hz), ωL and 1/
When compared with ωC, 7/ωL=3.38X10-3, and most of it flows to the first capacitor 22.

Therefore, the AC power supply 11 passes through the first glue actor 21.
The current in the AC power supply 11 has a sine waveform.

As is clear from the above, in this embodiment, the first actuator 21 and the first capacitor 22 are used not only for voltage regulation but also for harmonic blocking, so that harmonic power can be reduced with a simple structure. Obstacles can be removed.

For example, when the AC power supply 11 is an engine generator,
It becomes possible to increase the rated capacity by 30-40%.

Furthermore, in the case of a commercial power supply, the influence of harmonic currents on various devices connected thereto can be removed.

Moreover, according to this device, it is possible to improve the power factor.

Moreover, efficient voltage regulation becomes possible.

In the circuit as described above, the thyristor 23. When the gate signal is turned off due to breakdown of the thyristor control circuit 24 or failure of the thyristor control circuit 29, the second actuator 25
9. It is completely separated from 20.

And the lead current I of the capacitor 22. However, in the embodiment of the present invention, when an overvoltage condition occurs, the transistor 34 is turned on, the relay coil 37 is energized, and the switch 31 is closed to prevent overvoltage. The reactors 1 to 30 are connected to a pair of power lines 19. 20 and flows through this reactor 30? voltage is limited.

Therefore, although voltage control is not possible, it is possible to continue supplying power.

Next, FIG. 3 showing a second embodiment of the present invention will be described.

However, since the parts denoted by numerals 11 to 37 are substantially the same as those denoted by the same numerals in FIG. 1, the explanation thereof will be omitted.

In this embodiment, a third harmonic removal circuit is provided in parallel with the first capacitor 22, which removes the third harmonic from the third capacitor 41 and the fourth actuator 42.

Therefore, the first glue actor 21 and the first container 2
2 is designed to mainly remove the fifth harmonic.

In order to mainly remove the third harmonic by the third capacitor 41 and the fourth actuator 42, C of the third capacitor 41 and L of the fourth actuator 42 are set to the frequency f of the 31st harmonic. It is set so that f=27rJrζ.

Even with such a circuit, overvoltage can be prevented by the reactor 30.

FIG. 4 shows a third embodiment of the present invention.

In this third embodiment, the symbols 11-15, 18-2
0.22 to 37 are substantially the same as those indicated by the same reference numerals in the first embodiment, so their explanation will be omitted.

In comparison with the first embodiment, this third embodiment has a transformer 5
0 is provided, and the rectifier circuit 13 and the voltage adjustment and filter circuit are coupled thereto.

Therefore, the transformer primary winding 51 is connected to the AC power supply 11, and the transformer secondary winding 52 has a first terminal 53, a second terminal 54, a third terminal 55, and a fourth terminal. 56 are provided.

The first terminal 53 is connected to the first diode 14, the second diode 15 is connected to the second terminal 54, the third terminal 55 is connected to the intermediate line, and the first and second The cathodes of diodes 14 and 15 are commonly connected to form a center-tap type full-wave rectifier circuit 13.

Further, the capacitor 22 and reactors 25 and 30 are connected to a fourth terminal 56 which is a boost tap.

The transformer 50 is also configured to function as a resistor for regulating voltage and blocking harmonic currents by increasing the amount of induction caused by increasing the leakage magnetic flux.

For this reason, since the transformer 50 also has the function of the beam actor 21 in FIG. 1, the beam actor is omitted in this embodiment.

Further, in this embodiment, a tertiary winding 57 for detecting power supply voltage is provided.

Even with this structure, the same effects as in the first embodiment can be obtained.

Although the embodiments of the present invention have been described above, the present invention is not limited to these and can be further modified.

For example, in FIG. 4, an element corresponding to the actuator 21 in FIG. 1 may be provided between the power supply 11 and the primary winding 51.

Also, the capacitor 41 and reactor 4 in Fig. 3
2 may be added to the circuit of FIG. 4.

It is of course also applicable to three-phase or polyphase circuits.

Alternatively, a transformer may be connected to the three-phase AC power source, and a circuit similar to the secondary side of the transformer shown in FIG. 4 may be provided on the secondary side of the transformer.

Also, as shown by the chain line in FIG. 1, the thyristor 23. 24
A switch 31' is connected in parallel to the reactor 30 and the switch 31, and the thyristor 23.
The reactor 25 may be forcibly connected to the power lines 19 and 20 by short-circuiting the reactor 24 with three switches.

Further, voltage detection may be performed on the input side of the rectifier circuit 13.

It is also applicable to detecting the load current and adjusting the voltage to perform constant current control.

It is also applicable to load power supply devices other than storage batteries.

Furthermore, the thyristors 23 and 24 may be replaced with triacs or other switching elements.

Further, a transformer may be inserted between the first actuator 21 and the first capacitor 22 in FIG.

Further, the switch 31 may be an electronic switch.

In addition, the generation of gate control signals for thyristors 23 and 24 has stopped without changing the control signal for turning on switch 31 based on the rise in output voltage, or the generation of gate control signals for thyristors 23 and 24 has stopped.
The configuration may be based on detecting that the voltage across the thyristors 3 and 24 has become substantially equal to the power supply voltage, or that no current flows through the thyristors 23 and 24.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a DC power supply device according to a first embodiment of the present invention, and FIG. 2 is a waveform showing an AC power supply voltage waveform A and a voltage waveform B of the second glue actor 25 in the circuit of FIG. FIG. 3 is a circuit diagram showing a DC power supply device according to a second embodiment of the present invention, and FIG. 4 is a circuit diagram showing a DC power supply device according to a third embodiment of the present invention. In the symbols used in the drawings, 11 is an AC power supply, 12 is a load, 13 is a rectifier circuit, 19. 20 is a power line, 21 is a first glue actor, 22 is a first capacitor,
23. 24 is a thyristor, 25 is a second glue actor,
30 is a reactor for overcurrent prevention, and 31 is a switch.

Claims (3)

[Scope of utility model registration request] (1) An inductance circuit connected to an AC power supply, and a container connected to the AC circuit so that a leading current flows to reduce voltage drop in the inductance circuit.
a voltage adjusting reactor connected in parallel to the capacitor via a continuity control element; a voltage detection circuit that detects a voltage on the output side of the inductance circuit; a control circuit that controls the conduction control element so that the voltage becomes a predetermined value; and a control circuit that detects an increase in the voltage or that the conduction control element cannot be turned on and controls the overvoltage prevention reactor or the voltage. A voltage regulating device comprising: a switch that connects a regulating reactor in parallel to the capacitor. (2) The voltage regulator according to claim 1, wherein the inductance circuit is connected in series to an AC power line or is an actor. (3) The voltage regulating device according to claim 1, wherein the inductance circuit is a transformer in which the capacitor and the voltage regulating reactor are connected in parallel to a secondary winding.