Real time inductance monitoring in welding and cutting power supply

Patent metadata

Field	Value
Publication number	US-10118243-B2
Application number	US-201715782918-A
Country	US
Kind code	B2
Filing date	Oct 13, 2017
Priority date	Oct 14, 2011
Publication date	Nov 6, 2018
Grant date	Nov 6, 2018

Abstract

A system and method is provided for monitoring and displaying real time information regarding the inductance of the welding circuit, such that a user can monitor the performance of a power supply to determine if the system inductance is adversely affecting the operation of the power supply, and where the system can change the output signal based on the detected system inductance.

First claim

What is claimed is:

1. A system having a welding or cutting power supply, the power supply comprising:
a first output terminal;
a second output terminal;
a power component circuit coupled to each of said first and second output terminals which outputs an output signal through at least one of said first and second output terminals;
a voltage detection circuit which detects a reflected voltage across said first and second output terminals during a welding or cutting operation; and
a controller circuit which determines an inductance of said system during said welding or cutting operation based on said reflected voltage and changes a parameter of said output signal during said welding or cutting operation based on said determined inductance.

2. The system of claim 1 , wherein said parameter is one of a current ramp rate, a peak current level, a peak current duration, a tail out current rate, a background current, and a frequency of said output signal.

3. The system of claim 1 , wherein said controller circuit stops said welding or cutting operation based on said inductance.

4. The system of claim 1 , wherein said controller circuit changes a plurality of parameters of said output signal based on said inductance, where said plurality of parameters include at least two of a current ramp rate, a peak current level, a peak current duration, a tail out current rate, a background current, and a frequency of said output signal.

5. The system of claim 1 , wherein said controller circuit changes a wire feed speed of a consumable based on said inductance.

6. The system of claim 1 , further comprising a comparator circuit which compares said reflected voltage to a threshold voltage, wherein said reflected voltage is caused by said inductance when an output current of said power component circuit is changed, and wherein said threshold voltage is an output voltage limit for said power component circuit.

7. The system of claim 1 , wherein said controller circuit changes a short circuit clearing function of said output signal based on said inductance.

8. The system of claim 1 , wherein said controller circuit changes said output signal such that a current pulse has a first ramp rate, a second ramp rate and a transition point between said first and second ramp rates, where said first ramp rate is different than said second ramp rate, and at least one of said first ramp rate, said second ramp rate, and said transition point is determined based on said inductance.

9. The system of claim 8 , where said second ramp rate is in the range of 50 to 90% of said first ramp rate.

10. The system of claim 8 , where said second ramp rate is in the range of 75 to 90% of said first ramp rate.

11. The system of claim 1 , wherein said controller circuit determines an initial system inductance prior to starting said welding or cutting operation and determines an availability of welding current waveforms based on said initial system inductance.

12. The system of claim 1 , wherein said controller circuit determines an initial system inductance prior to starting said welding or cutting operation and determines at least one of a global inductance factor or a parameter specific scaling factor prior to said welding or cutting operation, where said global inductance factor or said parameter specific scaling factor are used to modify said output signal.

13. The system of claim 1 , wherein said controller circuit determines each of a global inductance factor and a parameter specific scaling factor, and uses each of said global inductance factor and said parameter specific scaling factor to modify said output signal.

14. A method of welding or cutting, comprising:
providing a welding or cutting power supply;
outputting a welding or cutting signal through at least one of a first output terminal and a second output terminal of said power supply to weld or cut a work piece;
detecting a reflected voltage across said first output terminal and said second output terminal during a welding or cutting operation of said work piece;
determining a system inductance based on said reflected voltage during said welding or cutting operation; and
changing a parameter of said welding or cutting signal, during said welding or cutting operation, based on said determined inductance.

15. The method of claim 14 , wherein said parameter is one of a current ramp rate, a peak current level, a peak current duration, a tail out current rate, a background current, and a frequency of said welding or cutting signal.

16. The method of claim 14 , further comprising stopping said welding or cutting operation based on said determined inductance.

17. The method of claim 14 , further comprising changing a plurality of parameters of said welding or cutting signal based on said inductance, where said plurality of parameters include at least two of a current ramp rate, a peak current level, a peak current duration, a tail out current rate, a background current, and a frequency of said welding or cutting signal.

18. The method of claim 14 , further comprising changing a wire feed speed of a consumable based on said determined inductance.

19. The method of claim 14 , further comprising comparing said reflected voltage to a threshold voltage, wherein said reflected voltage is caused by said inductance when an output current is changed, and wherein said threshold voltage is an output voltage limit for said power supply.

20. The method of claim 14 , further comprising changing a short circuit clearing function of said welding or cutting signal based on said inductance.

21. The method of claim 14 , further comprising changing said welding or cutting signal such that a current pulse of said signal has a first ramp rate, a second ramp rate and a transition point between said first and second ramp rates, where said first ramp rate is different than said second ramp rate, and at least one of said first ramp rate, said second ramp rate, and said transition point is determined based on said inductance.

22. The method of claim 21 , where said second ramp rate is in the range of 50 to 90% of said first ramp rate.

23. The method of claim 21 , where said second ramp rate is in the range of 75 to 90% of said first ramp rate.

24. The method of claim 14 , further comprising determining an initial system inductance prior to starting said welding or cutting operation and determining an availability of welding or cutting current waveforms based on said initial system inductance.

25. The method of claim 14 , further comprising determining an initial system inductance prior to starting said welding or cutting operation and determining at least one of a global inductance factor or a parameter specific scaling factor prior to said welding or cutting operation, where said global inductance factor or said parameter specific scaling factor are used to modify said welding or cutting signal.

26. The method of claim 14 , further comprising determining each of a global inductance factor and a parameter specific scaling factor, and using each of said global inductance factor and said parameter specific scaling factor to modify said welding or cutting signal.

Assignees

• Lincoln Global Inc

Inventors

• Peters Steven R
• Matthews William T

Classifications

• B23K9/1056

  by using digital means (B23K9/1068 takes precedence) · CPC title

• B23K9/1006

  Power supply · CPC title

• B23K9/1062 Primary

  with computing means · CPC title

• B23K9/0953

  using computing means · CPC title

• B23K9/32

  Accessories · CPC title