JPH09168282A - Power source apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To operates with two kinds of high and low level voltages and also improve the power factor of a power source apparatus. SOLUTION: The diodes 8, 9 and thyristors 6, 7 connected in series to the same polarity are connected to output terminals 10, 11, IGBT12, 13 are connected inversely in parallel to the thyristors 6, 7 and the connecting point of the diodes 8, 9 and that of IGBT12, 13 are connected to an AC power source 1 via a reactor 2. Smoothing capacitors 14, 15 are connected in series between output terminals 10, 11 and a triac 17 is connected between the connecting point of the smoothing capacitors 14, 15 and the connecting point of the diodes 8, 9. When a voltage of the power source 1 is 200V, a voltage switching apparatus 33 opens the triac 17 and when the voltage is 100V, the voltage switching apparatus 33 closes the triac 17. The voltage and current of the power source 1 are input to a control apparatus 32 and this apparatus 32 opens or closes IGBT12 when the voltage of the power source 1 is positive and opens or closes IGBT13 when the voltage is negative so that the current is capable of following the voltage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can be used in any two AC voltages having different values.
The present invention relates to an input voltage compatible power supply device.

[0002]

2. Description of the Related Art A power supply unit compatible with two input voltages is used as, for example, a welding power supply unit, a cutting machine power supply unit, an uninterruptible power supply unit and a switching power supply unit. Conventionally, 2
An input voltage-compatible power supply device, for example, a welding power supply device is disclosed in Japanese Utility Model Publication No. 3-855. A high voltage (eg 200
When the AC power supply of V) is supplied, in this welding power supply device, the high-voltage AC voltage is full-wave rectified by the rectifier, smoothed by the two smoothing capacitors connected in series, and supplied to the inverter. . Low voltage (eg 1
When an AC voltage of 00 V) is supplied to the welding power supply device, in this welding power supply device, the rectifier is switched to perform double voltage rectification. Then, the low-voltage AC voltage is double-voltage rectified by the switched rectifier and the two smoothing capacitors, and the inverter is supplied with the same voltage as when the high voltage was supplied. In this way, the voltage supplied to the inverter is maintained at the same value regardless of whether the AC voltage is high voltage or low voltage. The high frequency output voltage generated by the inverter is supplied to the output transformer, and the high frequency voltage induced on the secondary side of the output transformer is rectified and smoothed and supplied to the welding load.

[0003]

However, in such a power supply device, since the smoothing capacitor is used, there is a problem that the power factor is poor. Also, with this power supply,
When power supply is started, the smoothing capacitor is in a discharged state, so a large inrush current flows. In order to prevent this, there is also a problem that it is necessary to provide a current limiting resistor.

[0004]

According to the first aspect of the present invention,
A rectifying means is included, and the rectifying means has first and second series means each including two rectifying elements connected to the same polarity. Further, the first and second self-arc-extinguishing type semiconductor switching elements are connected in antiparallel to the rectifying elements of the first series means, respectively. In the rectifying means, the interconnection point of the rectifying element of the first series means and the first and second rectifying elements are connected.
And the interconnection point of the semiconductor switching elements is used as an input terminal connected to the AC power supply. These input terminals are connected to an AC power supply via a reactor. 2 above
At least two smoothing capacitors between the two output terminals,
They are connected in series. Switching means is connected between the interconnection point of the two smoothing capacitors and the input terminal on the side of the second series means. The opening / closing control means opens the opening / closing means when the voltage of the AC power source is equal to or higher than a predetermined threshold value, and closes the opening / closing means when the voltage of the AC power source is smaller than the threshold value. The voltage and current of the AC power supply are input to the control means. The control means opens and closes the first and second self-turn-off semiconductor switching elements so that the current of the AC power supply follows the voltage of the AC power supply.

According to the first aspect of the invention, when the voltage of the AC power supply is equal to or higher than the threshold value, the opening / closing control means opens the opening / closing means. At this time, the first and second series means and the first and second self-extinguishing type semiconductor switching elements form a full-wave rectifier circuit. When the voltage of the AC power supply is smaller than the threshold value, the opening / closing control means closes the opening / closing means. At this time, the first and second series means and the first and second self-arc-extinguishing type semiconductor switching elements constitute a voltage doubler rectifier circuit. In either case, the control means causes the output voltage of the AC power supply to follow the output current of the AC power supply by opening or closing the first or second self-extinguishing type semiconductor switching element according to the polarity of the AC power supply. There is.

According to a second aspect of the present invention, in the power supply device according to the first aspect, at least one of the rectifying elements of the first or second series means is a thyristor.

According to the second aspect of the present invention, since the firing angle of the thyristor can be gradually increased when the power supply device is started, it is possible to prevent a large inrush current from flowing through the smoothing capacitor.

The invention according to claim 3 has a rectifying means for rectifying by inputting an AC power source. This rectifying means includes first and second self-turn-off type semiconductor switching elements. Two smoothing capacitors connected in series for smoothing the output of the rectifying means are provided in the power supply device. An open / close switch is connected between the interconnection point of these smoothing capacitors and the rectifying means. The open / close switch causes the rectifying means to configure a full-wave rectifier circuit in the open state, and causes the rectifying means to configure a voltage doubler rectifier circuit in the closed state. An opening / closing control means for controlling the opening / closing switch is also provided. This opening / closing control means, when the voltage of the AC power supply is equal to or higher than a predetermined threshold value,
The opening / closing means is opened, and when the voltage of the AC power supply is smaller than a predetermined threshold value, the opening / closing means is opened. The output voltage and output current of the AC power supply are input to the switching element control means. The switching control means controls the opening and closing of the first and second self-turn-off semiconductor switching elements so that the output current follows the output voltage of the AC power supply.

According to the third aspect of the invention, when the AC voltage is equal to or higher than the threshold value, the opening / closing control means opens the opening / closing switch to operate the rectification means as a full-wave rectification circuit. Also,
When the AC voltage is smaller than the threshold value, the opening / closing control means closes the opening / closing switch to operate the rectification means as a voltage doubler rectification circuit. Then, the switching control means controls the first and second self-extinguishing semiconductor switching elements so that the output current of the AC power supply follows the output voltage of the AC power supply.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION As shown in FIG. 1, one terminal 1a of an AC power supply 1 is connected to one input terminal 4 of a rectifier 3 via a reactor 2 (may be a wiring reactor). There is. The other terminal 1b of the AC power supply 1 is connected to the other input terminal 5 of the rectifier 3.

The rectifier 3 is a bridge type having thyristors 6 and 7 and diodes 8 and 9. The anode of the thyristor 6 is connected to the input terminal 4, and the cathode is connected to one output terminal 10. The thyristor 7 has a cathode connected to the input terminal 4 and an anode connected to the other output terminal 11. These thyristors 6, 7
Form a first series circuit connected to the same polarity. The diode 8 has its anode connected to the input terminal 5 and its cathode connected to the output terminal 10. The diode 9 has a cathode connected to the input terminal 5 and an anode connected to the output terminal 11. Diodes 8 and 9
Constitutes a second series circuit connected to the same polarity as the thyristors 8 and 9.

A conductive path of a self-extinguishing type semiconductor switching device, for example, an IGBT 12 is connected in antiparallel with the thyristor 6. That is, in the thyristor 6, a current flows from the input terminal 4 to the output terminal 10, whereas this conductive path is
A current flows from the output terminal 10 side to the input terminal 4 side. Similarly, the conductive path of the IGBT 13 is connected in antiparallel with the thyristor 7. In the thyristor 7, current flows from the output terminal 11 side to the input terminal 4 side, whereas in this conductive path, current flows from the input terminal 4 side to the output terminal 11 side.

Smoothing capacitors 14 and 15 are connected in series between the output terminals 10 and 11 of the rectifier 3. An opening / closing means, for example, a triac 17, is connected between the interconnection point 16 of the smoothing capacitors 14 and 15 and the input terminal 5 of the rectifier 3.

Thyristors 6, 7, IGBTs 12, 13,
The triac 17 is on / off controlled by the control device 32. In order to control the thyristors 6 and 7 and the IGBTs 12 and 13, the control device 32 includes a terminal 1 a of the AC power supply 1,
The AC voltage between 1b is input, and the detected value of the input current to the rectifier 3 detected by the current transformer 31 provided between the terminal 1b and the input terminal 5 of the rectifier 5 is also input. As will be described later, the control device 32 controls ON / OFF of the thyristors 6 and 7 and the IGBTs 12 and 13 so that the input current to the rectifier 3 follows the AC voltage.

For controlling the triac 17, the control device 32 is provided with opening / closing control means, for example, a voltage switching device 33. This voltage switching device 33 has an auxiliary transformer 51 into which the AC voltage of the AC power supply 1 is input to the primary winding. This auxiliary transformer 51 induces an AC voltage, which is a reduction of the input AC voltage, in the secondary winding. The induced secondary AC voltage is rectified by the auxiliary rectifier 52 and smoothed by the smoothing capacitor 53. Zener diode 54 is connected in series between both ends of smoothing capacitor 52.
And a resistor 55 are connected. Smoothing capacitor 53
The collector-emitter conductive path of the switching transistor 56 and the relay 57 are connected in series between both ends of the. A relay contact 58, which is closed when the relay 57 is energized, is connected to the control device 32. Control device 3
No. 2 turns off the triac 17 when the relay contact 58 is closed, and turns on the triac 17 when the relay contact 58 is opened. The connection point between the Zener diode 54 and the resistor 55 is connected to the base of the switching transistor 56. The Zener diode 54 is used that is conductive when the AC voltage of the AC power supply 1 is 200 V, for example, and is non-conductive when the AC voltage is 100 V, for example.

The input side of the inverter 20 is connected between the smoothing capacitors 14 and 15. This inverter 2
0 is a self-extinguishing type semiconductor switching element, for example, IG
It is a half-bridge type that uses BTs 21 and 22. In the inverter 20, the conductive paths of the IGBTs 21 and 22 are connected in series between the smoothing capacitors 14 and 15. An inverter control signal is supplied from the inverter control device 23 to the bases of these IBGTs 21 and 22. Flywheel diodes 23a and 23b are connected to the conductive paths of the IGBTs 21 and 22, respectively.

The interconnection points of the conductive paths of the IGBTs 21 and 22 and the interconnection point 16 of the smoothing capacitors 14 and 15 are
That is, the output side of the inverter 20 is connected to the primary winding of the output transformer 26 via the DC cut capacitor 25. The output transformer 26 is provided to insulate the high frequency alternating current of the inverter 21 and reduce the voltage to a predetermined voltage. The output transformer 26 has output rectifiers 27 and 28 at both ends of the secondary winding.
It is connected to the output terminal 30a via the smoothing reactor 29. The other output terminal 30b is connected to the center tap of the secondary winding. A welding load, for example, is connected between the output terminals 30a and 30b.

Next, the AC voltage of the AC power supply 1 is as shown in FIG.
The operation in the case of a high voltage, for example, 200 V as shown by the solid line in (a) will be described. In this case, as described above, the relay contact 58 is closed and the triac 17 is off.

When the voltage at the terminal 1a of the AC power supply 1 becomes higher than the voltage at the terminal 1b, as shown at t0 in FIG. 2 (a), the thyristor 6 is connected to the control device 3 as shown in FIG. 2 (b).
2 is turned on. This state is the terminal 1 of the AC power supply 1.
It continues until time t1 when the voltage of a is higher than the voltage of the terminal 1b. That is, the thyristor 6 is in full conduction over the period of the positive half cycle of the AC power supply 1. Further, during this positive half cycle, the control device 32 turns the IGBT 13 on and off as shown in FIG.

When the IGBT 13 is on, a current flows from the terminal 1a of the AC power supply 1 to the terminal 1b of the AC power supply 1 through the reactor 2, the IGBT 13 and the diode 9. At this time, energy due to the voltage in the direction indicated by the arrow is accumulated in the reactor 2.

When the IGBT 13 is turned off, energy is released from the reactor 2 so that the current flowing through the reactor 2 flows in the same direction as before. As a result, current flows from the reactor 2 to the thyristor 6 and the smoothing capacitor 1
The smoothing capacitors 14 and 15 are charged by flowing to the reactor 2 through the diodes 4 and 15, the diode 9 and the terminal 1b of the AC power supply 1. The maximum voltage is about 280V (double the 200V route).

During a negative half cycle in which the voltage of the terminal 1b of the AC power supply 1 is higher than the voltage of the terminal 1b, as shown in the period from t1 to t2 in FIG. 2 (a), as shown in FIG. 2 (d). The control device 32 brings the thyristor 7 into conduction. That is, it is in full conduction. Further, during this half cycle, the control device 32 turns the IGBT 12 on and off.

When the IGBT 12 is on, a current flows from the terminal 1b of the AC power supply 1 to the terminal 1a of the AC power supply 1 through the diode 8, the IGBT 12 and the reactor 2. At this time, energy is accumulated in the reactor 2 by the voltage in the direction opposite to the arrow.

When the IGBT 12 is off, the reactor 2
So that the direction of the current flowing through the
AC power supply 1, diode 8, smoothing capacitor 14, 1
5, a current flows through the thyristor 7 and the reactor 2, the smoothing capacitors 14 and 15 are charged, and the voltage thereof reaches a maximum of about 280V.

By controlling the IGBTs 12 and 13 and the thyristors 6 and 7 in this manner, the AC voltage of the AC power source 1 is full-wave rectified and smoothed. The controller 32 uses the voltage of the AC power supply 1 as a reference so that the phase of the current flowing from the AC power supply 1 matches the phase of the voltage of the AC power supply 1.
The on / off period of the GBTs 12 and 13 is controlled. That is,
The IGBTs 12 and 13 are PWM-controlled to improve the power factor of the AC power supply 1.

For example, as a result of using this power supply device in a place different from the place where it has been used, the voltage of the AC power supply 1 is 100 V as shown by the dotted line in FIG. 2 (a).
It may be. In this case, the relay contact 58 is opened as described above, and the control device 32 causes the triac 17 to open.
Turn on.

When the voltage at the terminal 1a of the AC power supply 1 becomes higher than the voltage at the terminal 1b as shown at time t0 in FIG. 2 (a), the controller 32 causes the thyristor 6 to operate as shown in FIG. 2 (b). To turn on. This state lasts for a positive half cycle. Also, during this period, the control device 32
Turn on / off the GBT 13.

When the IGBT 13 is on, a current flows from the terminal 1a of the AC power source 1 to the terminal 1b of the AC power source 1 via the reactor 2, the IGBT 13, and the diode 9, and energy is accumulated in the reactor 2 by the voltage in the direction of the arrow. To be done. When the control device 32 turns off the IGBT 13,
The reactor 2 discharges the accumulated energy so that the current flowing through the reactor 2 is passed as it is, and the reactor 2
A current flows from the thyristor 6, the smoothing capacitor 14, the triac 17, and the terminal 1b of the AC power supply 1 to the reactor 2 to charge the smoothing capacitor 14. At this time,
The smoothing capacitor 14 has a maximum voltage of about 140 V (double the 100 V route).

At time t1 when the voltage at the input terminal 1b becomes higher than the voltage at the input terminal 1a, the controller 32 turns on the thyristor 7. This state continues for a negative half cycle. During this period, the IGBT 12 controls the control device 3
On and off are controlled by 2.

When the IGBT 12 is on, a current flows from the terminal 1b of the AC power supply 1 to the terminal 1a via the diode 8, the IGBT 12 and the reactor 2, and energy is accumulated in the reactor 2 by a voltage in the direction opposite to the arrow. IG
When the BT 12 is turned off by the control device 32, in order to make the direction of the current flowing through the reactor 2 the same as before, the reactor 2 is connected to the AC power supply 1, the triac 1
A current flows through the reactor 2 via the 7, the smoothing capacitor 15, and the thyristor 7. As a result, the smoothing capacitor 15
Is charged, and its voltage becomes about 140V.

By turning on the triac 17 in this manner, the rectifier 3 operates as a voltage doubler rectifier circuit. The control device 32 uses the voltage of the AC power supply 1 as a reference,
The ON / OFF periods of the IGBTs 12 and 13 are controlled so that the phase of the current flowing from the AC power supply 1 matches the phase of the voltage of the AC power supply 1. That is, the IGBTs 12 and 13 are PWM
The power factor of the AC power supply 1 is controlled and improved.

The voltage charged in the smoothing capacitors 14 and 15 is turned on / off by the inverter control device and is turned on / off.
High-frequency switching is performed by 21, 22 and a high-frequency AC voltage is obtained. This high frequency AC voltage is applied to the output transformer 2
It is stepped down by 6 and rectified and smoothed. This rectified and smoothed output is supplied to the welding load connected to the output terminals 30a and 30b.

By the way, when this power supply is started,
The smoothing capacitors 14 and 15 have been discharged. Therefore,
When the thyristors 6 and 7 are brought into full conduction from the start-up as described above, excessive currents flow in the capacitors 14 and 15, respectively. In order to prevent the occurrence of this excessive current, for example, in the case of the thyristor 6, the firing angle is gradually reduced from 180 degrees at every positive half cycle from the start,
The current flowing through the smoothing capacitors 14 and 15 is gradually increased. Similarly, the thyristor 7 is also controlled every negative half cycle at the time of starting. That is, the thyristors 6 and 7 are soft-started at the time of startup.

In the above embodiment, the triac 17 is used as the opening / closing means, but instead of this, for example, two thyristors connected in anti-parallel can be used. A relay contact driven by a relay 57 can be used instead of the triac 17.

In the above embodiment, the thyristors 6 and 7 are used as the rectifier 3. This is because a soft start is performed at the time of startup and an excessive current is prevented from being generated at the time of startup. However, an ordinary rectifier diode may be used instead of the thyristors 6 and 7 if a suitable current limiting means is provided.

Although the diodes 8 and 9 are used in the above embodiment, thyristors may be used instead of them. In this case, the thyristor replacing the diode 8 is turned on by the control device 32 when the thyristor 7 is on. Similarly, the thyristor in place of the diode 9 is a control device 3 when the thyristor 6 is on.
Turned on by 2.

[0037]

As described above, according to the invention described in claim 1 or 3, the power source is supplied to a predetermined load regardless of whether the voltage of the AC power source input to the power source device is high or low. The power factor is improved because the first and second self-extinguishing type semiconductor switching elements are controlled so that the current flowing from the AC power supply follows the voltage of the AC power supply as well as being supplied. be able to.

According to the invention of claim 2, the first
Alternatively, a thyristor is used as at least one rectifying element of the second series means. Therefore, since it is possible to perform a soft start at the time of startup, it is possible to reduce the inrush current flowing through the smoothing capacitor at the time of startup.

[Brief description of the drawings]

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

FIG. 2 is an operation waveform diagram of the same embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 AC power supply 2 Reactor 3 Rectifier circuit 6 7 Thyristor (first series means) 8 9 Diode (second series means) 12 13 IGBT (first and second self-extinguishing type semiconductor switching element) 14 15 Smoothing capacitor 17 Triac (opening / closing means) 32 Control device (controlling means) 33 Voltage switching device (opening / closing control means)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H02M 7/5387 9181-5H H02M 7/5387 A

Claims (3)

[Claims] 1. A first circuit which includes two rectifying elements connected to the same polarity and which is connected in parallel between two output terminals.
And second serial means, and first and second self-extinguishing type semiconductor switching elements respectively connected in antiparallel to the rectifying elements of the first series means, and the rectifying element of the second series means. And an interconnection point of the first and second semiconductor switching elements as an input terminal connected to an AC power source via a reactor, and a series connection between the two output terminals. At least two smoothing capacitors connected to each other, an interconnection point between the two smoothing capacitors, an opening / closing means connected between the input terminal on the second series means side, and a voltage of the AC power supply. When the voltage is equal to or higher than a predetermined threshold, the switching means is opened, and when the voltage of the AC power supply is smaller than the threshold, the switching control means that closes the switching means, and the voltage and current of the AC power supply are input. ,the above When the voltage of the AC power supply has one polarity, the first self-arc-extinguishing type semiconductor switching element is opened and closed so that the current of the AC power supply follows the voltage of the AC power supply, and the voltage of the AC power supply is the other. A power supply device comprising: a control unit that opens and closes the second self-arc-extinguishing type semiconductor switching element when the polarity is set. 2. The power supply device according to claim 1, wherein
Alternatively, at least one of the rectifying elements of the second series means is a thyristor. 3. A rectifying means for rectifying an AC power supply including first and second self-arc-extinguishing semiconductor switching elements, two smoothing capacitors connected in series for smoothing the output of the rectifying means, and these smoothing capacitors. An open / close switch that is connected between the interconnection point and the rectifying means, and that causes the rectifying means to form a full-wave rectifying circuit in the open state, and that forms a double voltage rectifying circuit in the rectifying means in the closed state, When the voltage of the AC power supply is equal to or higher than a predetermined threshold, the opening / closing means is opened, and when the voltage of the AC power supply is lower than the predetermined threshold, the opening / closing control means opens the opening / closing means, and the AC power supply The output voltage and the output current are input, and the output current follows the output voltage of the AC power supply.
And a switching element control means for controlling opening / closing of the second self-arc-extinguishing type semiconductor switching element.