Power supply for electric arc gas heater

Patent metadata

Field	Value
Publication number	US-2021051775-A1
Application number	US-202017084743-A
Country	US
Kind code	A1
Filing date	Oct 30, 2020
Priority date	Oct 1, 2014
Publication date	Feb 18, 2021
Grant date	—

Abstract

Such a design ensures the stability of the current control loop, while also ensuring a sufficient amount of current ripple to spread out the erosion zone on the electrodes of the torch.

First claim

1 . A switching converter for driving an electrode of a welding device, the switching converter comprising:
a pulse-width modulated chopper configured to operate at a switching frequency f s ; and a ballast inductor coupled to the pulse-width modulated chopper and configured to be coupled with the electrode, wherein:
the switching converter is configured to have a current control loop latency τ and an input voltage potential U 0 ; and
the ballast inductor has an inductance between

(

U
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0

1

5

0

0

)


τ


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and




1

f
s



(

U
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0

2

0
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0

)

.

2 . The switching converter of claim 1 , wherein the inductance has a minimum value to maintain a loop stability criterion under operation.

3 . The switching converter of claim 2 , wherein the inductance has a maximum value to produce a peak to peak current ripple to enhance wandering of electric arc roots on the electrode under operation.

4 . The switching converter of claim 1 , wherein the switching converter is a DC to DC buck converter.

5 . The switching converter of claim 1 , wherein U 0 >3000 volts.

6 . The switching converter of claim 1 , wherein the switching converter is configured to provide between 1 and 10 MW.

7 . The switching converter of claim 1 , wherein the welding device is a non-transferred electric arc gas heater is a non-transferred segmented plasma torch.

8 . The switching converter of claim 1 , wherein the electrode is a hollow electrode.

9 . The switching converter of claim 1 , wherein the switching converter is configured to produce a peak to peak current ripple of at least 50 amps over a duty cycle range of the pulse-width modulated chopper.

10 . The switching converter of claim 9 , wherein the duty cycle range is at least 20% to 80%.

11 . A method of operating a welding device having a switching converter coupled with an electrode, the method comprising:
providing a voltage potential U 0 to an input of the switching converter; and providing a current from an output of the switching converter to the electrode, wherein the switching converter comprises:
a pulse-width modulated chopper configured to operate at a switching frequency f s ; and
a ballast inductor coupled to the pulse-width modulated chopper and configured to be coupled with the electrode, wherein:
the switching converter is configured to have a current control loop latency τ and an input voltage potential U 0 ; and

the ballast inductor has an inductance between

(

U

0

1

5

0

0

)


τ



and




1

f
s



(

U

0

2

0

0

)

.

12 . The method of claim 11 , wherein the inductance has a minimum value to maintain a loop stability criterion under operation.

13 . The method of claim 12 , wherein the inductance has a maximum value to produce a peak to peak current ripple to enhance wandering of electric arc roots on the electrode under operation.

14 . The method of claim 11 , wherein the switching converter is a DC to DC buck converter.

15 . The method of claim 11 , wherein U 0 >3000 volts.

16 . The method of claim 11 , wherein the switching converter is configured to provide between 1 and 10 MW.

17 . The method of claim 11 , wherein the welding device is a non-transferred electric arc gas heater is a non-transferred segmented plasma torch.

18 . The method of claim 17 , wherein the electrode is a hollow electrode.

19 . The method of claim 11 , wherein the switching converter is configured to produce a peak to peak current ripple of at least 50 amps over a duty cycle range of the pulse-width modulated chopper.

20 . The method of claim 19 , wherein the duty cycle range is at least 20% to 80%.

Assignees

• Umicore Nv

Inventors

• Ostermeyer John
• Heulens Jeroen

Classifications

• H05H1/36

  Circuit arrangements (H05H1/38, H05H1/40 take precedence) · CPC title

• H05B7/185 Primary

  Heating gases for arc discharge (gas-filled discharge tubes H01J37/32) · CPC title

• H05B7/144

  Power supplies specially adapted for heating by electric discharge; Automatic control of power, e.g. by positioning of electrodes · CPC title

• B23K9/073

  Stabilising the arc · CPC title