GB2039168A - Power source for arc welding - Google Patents
Power source for arc welding Download PDFInfo
- Publication number
- GB2039168A GB2039168A GB7943191A GB7943191A GB2039168A GB 2039168 A GB2039168 A GB 2039168A GB 7943191 A GB7943191 A GB 7943191A GB 7943191 A GB7943191 A GB 7943191A GB 2039168 A GB2039168 A GB 2039168A
- Authority
- GB
- United Kingdom
- Prior art keywords
- power source
- welding
- phase
- rectifiers
- controllable rectifiers
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 238000003466 welding Methods 0.000 title claims abstract description 28
- 238000004804 winding Methods 0.000 claims abstract description 17
- 239000011261 inert gas Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000003990 capacitor Substances 0.000 description 1
- 238000009499 grossing Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M5/00—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases
- H02M5/02—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc
- H02M5/04—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters
- H02M5/22—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M5/25—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a thyratron or thyristor type requiring extinguishing means
- H02M5/27—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a thyratron or thyristor type requiring extinguishing means for conversion of frequency
- H02M5/271—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a thyratron or thyristor type requiring extinguishing means for conversion of frequency from a three phase input voltage
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K9/00—Arc welding or cutting
- B23K9/10—Other electric circuits therefor; Protective circuits; Remote controls
- B23K9/1006—Power supply
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F30/00—Fixed transformers not covered by group H01F19/00
- H01F30/06—Fixed transformers not covered by group H01F19/00 characterised by the structure
- H01F30/12—Two-phase, three-phase or polyphase transformers
- H01F30/14—Two-phase, three-phase or polyphase transformers for changing the number of phases
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- Plasma & Fusion (AREA)
- Mechanical Engineering (AREA)
- Arc Welding Control (AREA)
- Arc Welding In General (AREA)
- Generation Of Surge Voltage And Current (AREA)
Abstract
In a power source for arc welding, a three-phase transformer (10) is connected to a three-phase network (R, S, T) and, in addition, controllable rectifiers are provided for generating an alternating single- phase welding current which is one- and-one-half or three times the supply frequency. In order to obtain the desired welding current frequency with as small a number of controllable rectifiers as is possible, the primary windings (11, 12, 13) in the three- phase transformer (10) are delta connected and the secondary windings (14, 15, 16) are star connected and, in addition, each secondary winding (14, 15, 16) is arranged in series with two antiparallel- connected controllable rectifiers (17/18, 19/20, 21/22), the rectifiers (17 to 22) being connected to a workpiece (25) via the centre tap of a choke (23) and the centre point (M) of the secondary windings (14, 15, 16) being connected to a welding torch (26). <IMAGE>
Description
SPECIFICATION
Power source for arc welding
The present invention relates to a power source for arc welding, comprising a threephase transformer, connected to a three-phase network, and controllable rectifiers for generating a single-phase alternating current with a welding current frequency which is one-andone-half or three times the supply frequency.
The above statement refers to a state of the art which has become known, for example, from early published German Specification
No. 26 56 980. In this specification a power source for arc welding is described with which a single-phase alternating current can be generated, the frequency of which is selectively three or one-and-one-half times the value of the supply frequency (50 or 60 Hz), the threephase network being loaded symmetrically.
This is made possible by simple control of the rectifiers provided so that, at predetermined times, certain rectifiers are open or closed in such a manner that the above-mentioned frequency of the single-phase alternating welding current is produced.
For the known power source twelve controllable rectifiers are required for generating the required welding current frequency, which is not of advantage with respect to volumetric shape and production costs.
It is an object of the present invention to improve a power source of the type mentioned above in such a manner that the above-mentioned disadvantages are avoided, particularly with reference to the number of controllable rectifiers.
In order to achieve this object, it is proposed according to the present invention to construct a power source of the type mentioned above in such a manner that the threephase transformer is provided with delta-connected primary windings and with star-connected secondary windings, that furthermore each secondary winding is arranged in series with one connection of two and antiparallelconnected controllable rectifiers the other connection of which is connected to a workpiece, and that, in addition to that, the centre point of the secondary windings is connected to a welding torch.
This circuit arrangement has the advantage that only six controllable rectifiers are required for generating a single-phase alternating welding current, while retaining the above-mentioned required welding current frequency and symmetrical loading of the three-phase supply network. In this way the size and weight of the welding system is reduce and, in addition, the drive requirements for the controllable rectifiers are reduced which is advantageous for production and also for maintenance.
The controllable rectifiers are used simultaneously for adjusting the welding current by means of phase control so that expensive components for this, such as leakage reactance cores, transductors, change-over windings with step switching, and so forth, can be omitted .
In the description which follows the power source according to the invention is set out in greater detail with reference to the accompanying drawing showing a circuit layout.
The power source according to the invention is provided by a three-phase transformer 10 which is connected to a three-phase
R-S-T network. The primary windings 11, 12, 13 of the transformer 10 are preferably delta-connected and the secondary windings 14, 15, 16, in contrast, star-connected. Each of the secondary windings 14, 15, 16 is arranged in series with two antiparallel-connected controllable rectifiers 1 7/1 8 and 19/20 and 21/22 which are connected to a workpiece 25 via a choke 23 with a centre tap 24. The centre point M of the starconnected secondary windings 14, 15, 16 is connected to a welding torch 26, shown diagrammatically.
It is particularly advantageous if the controllable rectifiers 17-22 are provided as thyristors. The thyristors 17-22 are driven via a control device 27 which is provided with a program transmitter 28 which is associated with the control electrodes of the thyristors and which is used to set (program) the opening and closing times of the thyristors 17-22, in such a manner that the welding current is a single-phase current and has a frequency which is three or one-and-one-half times the frequency of the supply network.
The power source is used preferably for tungsten inert-gas welding (TIG-welding). For
AC-TIG-welding preferably two separate control circuits/program transmitters 27/28 are provided which monitor the positive halfwaves and the negative halfwaves separately from one another so that a symmetrical singlephase current can be generated whilst still loading the transformer and the supply network symmetrically, in such a manner that both the positive and the negative halfwave can be adjusted continuously from 0-100%.
The capacitors 29 provided are used for smoothing and for filling gaps (especially with small currents) and, if suitably dimensioned, round off the output wave-shape to a continuous sine-wave even where there is a lack of symmetry.
It will of course be understood that the power source can also be used in conjunction with submerged arc-welding systems having high alternating welding currents, with shielded inert gas metal arc welding systems having fusible electrodes and with processes of a similar type.
Instead of using thyristors as the controllable switches and rectifiers, other equivalent electric or electronic components can also be used. It is also possible to use two different components, each of which exercises one of the said functions (switching and rectifying), such as, for example, a diode and a switching transistor connected in series.
Claims (4)
1. A power source for arc welding, comprising a three-phase transformer connected to a three-phase network, and controllable rectifiers for generating an alternating single-phase welding current with a welding current frequency which is one-and-one-half or three times the supply frequency, characterised in that the three-phase transformer (10) is provided preferably with delta-connected primary windings (11, 12, 13) and preferably starconnected secondary windings (14, 15, 16), that each secondary winding (14, 15, 16) is arranged in series with two antiparallel-connected controllable rectifiers (7/18, 19/20, 21/22) which are connected to a workpiece (25), and that the centre point (M) of the secondary windings (14, 15. 16) is connected to a welding torch (26).
2. A power source according to claim 1, characterised in that the controllable rectifiers (17 to 22) are in the form of thyristors.
3. A power source according to claim 1 or claim 2, characterised in that the thyristors (17 to 22) are driven via a control device (27) which is provided with a program transmitter (28), which is in the form of a timing generator, for setting the opening and closing time of the thyristors (17 to 22).
4. A power source for arc welding, substantially as hereinbefore described with reference to, or as shown in, the accompanying drawing.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19782855664 DE2855664A1 (en) | 1978-12-22 | 1978-12-22 | POWER SOURCE FOR ARC WELDING |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB2039168A true GB2039168A (en) | 1980-07-30 |
Family
ID=6058120
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB7943191A Withdrawn GB2039168A (en) | 1978-12-22 | 1979-12-14 | Power source for arc welding |
Country Status (7)
| Country | Link |
|---|---|
| JP (1) | JPS5588984A (en) |
| BR (1) | BR7908322A (en) |
| DE (1) | DE2855664A1 (en) |
| FR (1) | FR2444529A1 (en) |
| GB (1) | GB2039168A (en) |
| IT (1) | IT1126530B (en) |
| SE (1) | SE7909926L (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5340963A (en) * | 1990-02-15 | 1994-08-23 | Miller Electric Mfg. Co. | Alternating current power source for welding |
| EP0884127A1 (en) * | 1997-06-11 | 1998-12-16 | Illinois Tool Works Inc. | Method and apparatus for producing welding power |
| US6177651B1 (en) * | 1998-06-11 | 2001-01-23 | Illinois Tool Works Inc. | Method and apparatus for producing welding power |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4435632A (en) * | 1982-02-12 | 1984-03-06 | Hobart Brothers Company | Three phase square wave welding power supply |
| AT411444B (en) * | 2000-06-28 | 2004-01-26 | Fronius Schweissmasch Prod | WELDING MACHINE, WHICH ON ONE, TWO OR THREE-PHASE NETWORKS CAN BE OPERATED |
-
1978
- 1978-12-22 DE DE19782855664 patent/DE2855664A1/en not_active Withdrawn
-
1979
- 1979-11-30 SE SE7909926A patent/SE7909926L/en not_active Application Discontinuation
- 1979-12-07 IT IT27945/79A patent/IT1126530B/en active
- 1979-12-10 JP JP15930679A patent/JPS5588984A/en active Pending
- 1979-12-14 GB GB7943191A patent/GB2039168A/en not_active Withdrawn
- 1979-12-19 BR BR7908322A patent/BR7908322A/en unknown
- 1979-12-21 FR FR7931508A patent/FR2444529A1/en active Granted
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5340963A (en) * | 1990-02-15 | 1994-08-23 | Miller Electric Mfg. Co. | Alternating current power source for welding |
| EP0884127A1 (en) * | 1997-06-11 | 1998-12-16 | Illinois Tool Works Inc. | Method and apparatus for producing welding power |
| US6114655A (en) * | 1997-06-11 | 2000-09-05 | Illinois Tool Works Inc. | Method and apparatus for producing welding power |
| US6278081B1 (en) * | 1997-06-11 | 2001-08-21 | Illinois Tool Works Inc. | Method and apparatus for producing welding power |
| US6177651B1 (en) * | 1998-06-11 | 2001-01-23 | Illinois Tool Works Inc. | Method and apparatus for producing welding power |
Also Published As
| Publication number | Publication date |
|---|---|
| DE2855664A1 (en) | 1980-07-03 |
| IT7927945A0 (en) | 1979-12-07 |
| FR2444529B3 (en) | 1982-05-07 |
| IT1126530B (en) | 1986-05-21 |
| SE7909926L (en) | 1980-06-23 |
| FR2444529A1 (en) | 1980-07-18 |
| JPS5588984A (en) | 1980-07-05 |
| BR7908322A (en) | 1980-09-16 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |