SU1382615A1 - Power supply source for arc welding - Google Patents

Abstract

The invention relates to welding production and can be used for plasma, microplasma and argon arc welding with non-consumable electrode of aluminum alloys with alternating current. The aim of the invention is to improve the quality of the weld. To do this, in a power supply device containing a transformer, an inductive energy storage device, four thyristors and a control unit, each of the two sections of the secondary winding of the transformer is connected in parallel to one of the sections of the inductive energy storage device. During the first phase of operation of the source, the first section of the accumulator is charged from the transformer, and the second is discharged into an arc. In this way, a positive current pulse is generated. During the second phase of operation of the source, the second section of the accumulator is charged from the transformer, and the first discharges into an arc, forming a negative pulse of the welding current. 1 hp ff, 4 ill. (L

Description

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The invention relates to welding production and can be used for plasma, microplasma and argo-arc welding with non-consumable electrode of aluminum alloys with alternating current.

The purpose of the invention is to improve the quality of the weld.

FIG. 1 is a schematic diagram of the proposed arc welding power source; in fig. 2 - graphs of currents and voltages; in fig. 3 is a schematic diagram of a power source for arc welding with a two-section secondary winding of a transformer; in fig. 4 shows the graphs of currents and voltages in the circuit of FIG. 3

and section 9-6 is discharged due to dissipation of its energy in the arc gap 8-10. At time / 2, the current of section 5-9 reaches a maximum, and the voltage of the winding 13 changes its sign to 5. At the same time, the energy from section 5-9 partially recovers into the network via transformer 1 and the current in it decreases slightly. At time / 3, at negative negative voltage wave of the winding 13, the control unit 7 switches on the thyristors 4 n 11. The thyristors 3 and 12 are switched off, as the voltage of the winding 13 is applied in the opposite direction through the open thyristors 11 and 4, respectively, and the arc interval 8-10. Current section 5-9 pro10

The power source for arc welding, 5 flows around the contour 5-9-8-10-11 - 5, and the current

(Fig. 1) contains a transformer 1, two sections 9-6 - along the contour 9-6-4-13-9.

sectional inductive energy storage device 2 — In this case, the current through the arc gap of 8-gia, the first 3 and second 4 thyristors connected to the leads 5 and 6 of the inductive energy storage device 2, the control unit 7 connected to the control electrodes 20 of the thyristors, the first working electrode 8 , connected to the point 9 of the connection of the sections of the inductive storage device 2, the second working electrode 10, the third 11 and the fourth 12 thyristors. The secondary winding 13 of the transformer 1 is connected between the connection point 14 of the first 3 and second 4 thyristors and the connection point 9 of the inductive energy storage unit 2, the third 11 and the fourth 12 thyristors are connected in series and connected between the terminals 5 and 6 of the inductive energy storage unit, and connection point 15 the third 1 1 and fourth 12 thyristors are connected to the second working electrode 10.

FIG. 2 curve 16 is a graph of the voltage on the secondary winding 13 of transformer 1; curve 17 is a graph of the current in the arc between the working electrodes 8 and 10; curve 18 is a graph of current through section 5-9; curve 19 is a graph of current through section 9-6.

The power source for arc welding (Fig. 1) works as follows. 40

In the steady state, the arc between the working electrodes 8 and 10 is excited, currents flow through sections 5–9 and 9–6.

10 abruptly reverses the sign and a negative current pulse is generated. Section 9-6 is charged from the winding 13 and the current in it increases, and section 5-9 is discharged due to the dissipation of its energy in the arc gap 8-10. At time 4, the current of section 9-6 reaches a maximum, and the voltage of the winding 13 changes its sign and becomes positive again. At the same time, the energy from section 9-6 partially recovers into the network through transformer 1 and the current in it decreases slightly. At tf, with positive polarity, the voltage of the winding 13 circuit returns to the initial 30 state, the thyristors 3 and 12 are wired into the control unit 7 and then the power supply operates in the same way.

Changing the moments t, 1z and / 5 of switching on thyristors 3, 4, And 12, you can adjust the amount of current in the arc gap and the ratio of the durations of the pulses of currents of the direct and reverse polarities, and change the ratio of inductances of sections 5-9 and 9-6 For example, by varying the number of turns thereof, the ratio of the amplitudes of different polarities can be changed. The power source for arc welding (Fig. 3) contains a transformer 20, a two-section inductive energy storage 21, first 22 and second 23 thyristors, connected to inductive terminals 24 and 25

the direction of which is shown in FIG. 1 of the energy storage 21, unit 26 controllers.

At time / 1 (Fig. 2) with a positive voltage half-wave on the secondary winding 13 of transformer 1 (polarity shown in Fig. 1 without brackets), control unit 7 switches on thyristors 3 and 12. At the same time, thyristors 4 and 11 are turned off states, since the reverse voltage is applied to them through open thyristors 12 and 3, respectively, and arc gap 8-10. The current of the spacing section 5-9 connected to the thyristor control electrodes, the first working electrode 27 connected to the connection point 28 of the sections of the inductive energy storage 21, the second working electrode 29, 50 than the secondary winding of the transformer 20 is made in the form of two connected sections 30 and 31 with a tap 32 from the point of their connection, the third 33 and the fourth 34 are thyristors, with the first section 30 of the secondary winding of the transformer 20 through the first

The circuit flows 5-9-13-3-5, and the current of the 55- thyristor 22 is connected in parallel to the perception 9-6 - along the circuit 9-16-12-10-8-9, the inductive section 24-28 accumulates through the arc gap 8-10 positive current pulse. Section 5-9 is charged from the network through transformer 1,

l 21 energy, the second section 31 of the secondary winding of the transformer 20 through the second thyristor 23 is connected in parallel, the second section 9-6 is discharged due to the dissipation of its energy in the arc gap 8-10. At time / 2, the current of section 5-9 reaches a maximum, and the voltage of the winding 13 changes its sign. At the same time, the energy from section 5-9 partially recovers into the network via transformer 1 and the current in it decreases slightly. At time / 3, at negative negative voltage wave of the winding 13, the control unit 7 switches on the thyristors 4 n 11. The thyristors 3 and 12 are switched off, as the voltage of the winding 13 is applied in the opposite direction through the open thyristors 11 and 4, respectively, and the arc interval 8-10. Current section 5-9 pro

The circuit runs 5-9-8-10-11 - 5, and the current

In this case, the current through the arc gap 8-

0

0

10 abruptly reverses the sign and a negative current pulse is generated. Section 9-6 is charged from the winding 13 and the current in it increases, and section 5-9 is discharged due to the dissipation of its energy in the arc gap 8-10. At time 4, the current of section 9-6 reaches a maximum, and the voltage of the winding 13 changes its sign and becomes positive again. At the same time, the energy from section 9-6 partially recovers into the network through transformer 1 and the current in it decreases slightly. At the time tf at positive polarity, the voltage of the winding 13 circuit returns to the initial 0 state, the thyristors 3 and 12 are wired into the control unit 7 and then the power supply operates in the same way.

Changing the moments t, 1z and / 5 of switching on thyristors 3, 4, And 12, you can adjust the amount of current in the arc gap and the ratio of the durations of the pulses of currents of the direct and reverse polarities, and change the ratio of the inductances of the sections 5-9 and 9-6, For example, by varying the number of turns thereof, the ratio of the amplitudes of different polarities can be changed. The power source for arc welding (Fig. 3) contains a transformer 20, a two-section inductive energy storage 21, the first 22 and second 23 thyristors connected to the outputs 24 and 25 of inductive 5

 power storage device 21, control unit 26 connected to thyristor control electrodes, first working electrode 27 connected to connection point 28 of inductive energy storage 21, second working electrode 29, the secondary winding of transformer 20 being made in the form of two connected sections 30 and 31 with a tap 32 from the point of their connection, the third 33 and the fourth 34 are thyristors, with the first section 30 of the secondary winding of the transformer 20 through the first

thyristor 22 is connected in parallel to the first section 24-28 of inductive accumulate thyristor 22 is connected in parallel to the first section 24-28 of inductive energy storage 21, the second section 31 of the secondary winding of transformer 20 through the second thyristor 23 is connected in parallel to the second section of inductive energy storage 21, section 31 of the secondary winding of the transformer 20 through the second thyristor 23 is connected in parallel to the second section 28-25 of the inductive accumulator 21, the third 33 and the fourth 34 thyristors are connected in series and connected between pins 24 and 25 of the first 24-28 and second 28-25 sections of the inductive energy storage 21, and point 35 of the connection of the third 33 and fourth 34 thyristors are connected to 10 of the second working electrode 29.

FIG. 4 curve 36 is a graph of the voltage of sections 30 and 31 relative to tap 32; curve 37 - graph of current through

the current 27-29 is applied in the opposite direction to the voltage of section 31. The current of section 28 25 flows along the circuit 28-25-23 31 - 32-28, and the current of section 24-28 - along the circuit 24-28-27-29-35- 33-24 forming a negative current pulse through the arc gap 27-29, the current at time L (changing its direction to the opposite jump. Section 28 35 is charged from section 31 of the secondary winding of the transformer 20, and section 24-28 is discharged for the dissipation of its energy in the arc gap 27-29. At the moment / 4 the current of section 28 25 reaches a maximum, and the voltage of sections 30 and 31 changes its sign and stanod traction interval 27-29;. Curve 38 - Wits again positive at this ener25

thirty

current graph through section 24-28 of inductive storage device 21; curve 39 is a graph of the current through section 28-25 of the inductive drive 21.

The power source for arc welding (Fig. 3) works as follows.

In the steady state, the arc between the working electrodes 27 and 29 is excited, currents flow through sections 24-28 and 28-25, the direction of which is shown in FIG. 3 arrows.

At time I (Fig. 4) with a positive half-wave of voltages on sections 30 and 31 of the secondary winding of the transformer 20 (the polarity is shown in Fig. 3 without brackets), the control unit 26 includes thyristors 22 and 34. Thyristors 23 and 33 are in the off state, since the thyristor 23 through the open thyristor 34 and the arc gap 27-29 is applied in the opposite direction to the voltage of section 31, and to the thyristor 33 through the open thyristor 22 and the arc gap 27-29 is applied in the opposite direction. section 30. Current section 24-28 flows along the contour 24-28-3 2-30-22-24, and the current section 28-25 - along the contour 28-25-34-35- 29-27-28, forming a positive current pulse through the arc gap 27-29. Section 24-28 of inductive accumulator 21 is charged from section 30 of the secondary winding of transformer 20, and section 28-25 is discharged due to dissipation of its energy in the arc gap 27-29. At time / 2, the current of section 24-28 reaches a maximum, and the voltages of sections 30 and 31 change their sign. At the same time, the energy from section 24-28 partially recovers into the network through transformer 20 and the current in it decreases slightly. At time 3 with negative voltages (the polarity is shown in Fig. 3 in brackets) of sections 30 and 31, the control unit 26 turns on the thyristors 23 and 33. The thyristors 22 and 34 are switched off, since to the thyristor 22 through the open thyristor 33 and the arc gap 27-29 is applied in the opposite direction to the voltage of section 30, and to thyristor 34 through open thyristor 23 and arc gap from section 28-25 the particle recovers to the network through transformer 20 and the current in it decreases slightly. At time 5, with the positive polarity of the voltages of sections 30 and 31, the circuit returns to its original state, the control unit 26 turns on the thyristors 22 and 34, and then the power supply operates in a similar way.

By varying the times ti, / 3 and / 5 of the switching on of the thyristors 22, 23, 33 and 34, the current in the arc gap and the ratio of the durations of the current and reverse polarity current pulses can be adjusted, and the ratio of the inductances of the sections 24-28 and 28-25 can be changed. for example, by changing the number of turns, you can adjust the ratio of the amplitudes of different polarities.

In addition, by changing the ratio of the voltages of sections 30 and 31 of the secondary winding of the transformer 20, you can adjust the level of a constant component of the magnetic flux of the transformer to compensate for it.

Compared to the known power source of the inductive accumulator section, the 1H of the energy in the proposed power supply is made without magnetic coupling between them, which eliminates the influence of the scattering inductance of the inductive storage drive, which reduces the zero-current rate. Therefore, the steepness of the current pulse fronts increases significantly, which reduces the deionization of the arc gap. This leads to an increase in the stability of the arc and, as a result, to an improvement in the quality of welded pv.

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Claims (2)

Invention Formula . A power source for arc welding, containing a transformer, a two-section inductive energy storage device, first, second, third and fourth thyristors connected to the output of an inductive energy storage device, a control unit connected to the control electrodes of the thyristors, the first working electrode , the attachments 27-29 are applied in the opposite direction to the voltage of section 31. The current of section 28 25 flows along the circuit 28-25-23-33-28 and the current of section 24-28 circuits 24-28-27-29-35 - 33-24, forming a negative current pulse through the arc gap 27-29, The current at time L (changes its direction to the opposite jump. Section 28 35 is charged from section 31 of the secondary winding of the transformer 20, and section 24-28 is discharged due to dissipation of its energy over the arc gap 27-29. At the time / 4 the current of section 28 25 reaches a maximum, and the voltage of sections 30 and 31 changes its sign and becomes positive again. The cells from section 28-25 of the particle recover into the network through the transformer 20 and the current in it is somewhat reduced. At time 5, with the positive polarity of the voltages of sections 30 and 31, the circuit returns to its initial state, the control unit 26 turns on the thyristors 22 and 34, and then the power supply operates in a similar way. By varying the times ti, / 3 and / 5 of the switching on of the thyristors 22, 23, 33 and 34, the current in the arc gap and the ratio of the durations of the current and reverse polarity current pulses can be adjusted, and the ratio of the inductances of the sections 24-28 and 28-25 can be changed. for example, by changing the number of turns, you can adjust the ratio of the amplitudes of different polarities. In addition, by changing the ratio of the voltages of sections 30 and 31 of the secondary winding of the transformer 20, it is possible to adjust the level of the constant component of the magnetic flux of the transformer in order to compensate for it. Compared to the known power source of the inductive accumulator section, the 1H of the energy in the proposed power supply is made without magnetic coupling between them, which eliminates the influence of the scattering inductance of the inductive storage drive, which reduces the zero-current rate. Therefore, the steepness of the current pulse fronts increases significantly, which reduces the deionization of the arc gap. This leads to an increase in the stability of the arc and, as a result, to an improvement in the quality of welded pv. 0 Invention Formula . A power source for arc welding, containing a transformer, a two-section inductive energy storage device, first, second, third and fourth thyristors connected to the output of an inductive energy storage device, a control unit connected to the control electrodes of the thyristors, the first working electrode connected to the junction point of the inductive accumulator, the second working electrode, the transformer secondary winding being made in the form of two sections connected by ends with a tap from the place of their connection, with t first and fourth thyristors connected in series and are connected between the terminals of the first and second sections of the inductive energy accumulator, and the point of connection of the third and fourth thyristors attached to the second working electrode, characterized in that, in order improving the quality of the weld, the first section of the secondary winding of the transformer through the first thyristor is connected in parallel to the first section of the inductive energy storage, and the second section of the secondary winding of the transformer through the second thyristor is connected in parallel to the second section of the inductive energy storage. 2. The power supply according to claim 1, characterized in that the beginnings of the secondary sections of the transformer are electrically connected. Phi2.2 to t Pha2.