Systems and methods to control pulse welding

Patent metadata

Field	Value
Publication number	US-2020122261-A1
Application number	US-201916653488-A
Country	US
Kind code	A1
Filing date	Oct 15, 2019
Priority date	Oct 19, 2018
Publication date	Apr 23, 2020
Grant date	—

Abstract

Systems and methods to control pulse welding are disclosed. An example welding-type system includes: power conversion circuitry configured to convert input power to welding-type power; and control circuitry configured to control the power conversion circuitry to output the welding-type power in a plurality of pulse cycles, each pulse cycle comprising a background phase, a ramp up phase, a peak phase, and a ramp down phase. Controlling the power conversion circuitry involves: during the ramp up phase of the pulse cycles, controlling the power conversion circuitry in a current-controlled mode and switching to controlling the power conversion circuitry in a voltage-controlled mode when a peak transition voltage is reached; and during the ramp down phase of the pulse cycles, controlling the power conversion circuitry in a current-controlled mode and switching to controlling the power conversion circuitry in a voltage-controlled mode when a background transition voltage is reached.

First claim

What is claimed is:

1 . A welding-type system, comprising:
power conversion circuitry configured to convert input power to welding-type power; and control circuitry configured to control the power conversion circuitry to output the welding-type power in a plurality of pulse cycles, each pulse cycle comprising a background phase, a ramp up phase, a peak phase, and a ramp down phase, wherein the controlling the power conversion circuitry comprises:
during the ramp up phase of the pulse cycles, controlling the power conversion circuitry in a current-controlled mode and switching to controlling the power conversion circuitry in a voltage-controlled mode when a peak transition voltage is reached; and
during the ramp down phase of the pulse cycles, controlling the power conversion circuitry in the current-controlled mode and switching to controlling the power conversion circuitry in the voltage-controlled mode when a background transition voltage is reached.

2 . The welding-type system as defined in claim 1 , wherein the control circuitry is configured to:
control the power conversion circuitry based on a peak voltage during the peak phase of the pulse cycles, and determine the peak transition voltage based on the peak voltage, wherein the peak transition voltage is lower than the peak voltage.

3 . The welding-type system as defined in claim 1 , wherein the control circuitry is configured to:
control the power conversion circuitry based on a background voltage during the background phase of the pulse cycles, and determine the background transition voltage based on the background voltage, wherein the background transition voltage is higher than the background voltage.

4 . The welding-type system as defined in claim 1 , wherein the control circuitry is configured to control the power conversion circuitry in the voltage-controlled mode by controlling the power conversion circuitry based on comparing an output voltage of the power conversion circuitry to a target voltage.

5 . The welding-type system as defined in claim 4 , wherein the control circuitry is configured to set the target voltage to be a peak voltage during the peak phases and set the target voltage to be a background voltage during the background phases.

6 . The welding-type system as defined in claim 1 , wherein the control circuitry is configured to control the power conversion circuitry in the current-controlled mode by controlling the power conversion circuitry based on comparing an output current of the power conversion circuitry to a target current.

7 . The welding-type system as defined in claim 6 , wherein the control circuitry is configured to ramp up the target current during the ramp up phases and ramp down the target current during the ramp down phases.

8 . The welding-type system as defined in claim 1 , wherein the control circuitry is configured to, during the ramp up phase:
control the power conversion circuitry in the current-controlled mode by ramping up an output current of the power conversion circuitry from a background current; monitor an output voltage of the power conversion circuitry while the output current is increasing; and in response to detecting that the output voltage satisfies the peak transition voltage, control the power conversion circuitry to output the output current based on comparing the output voltage to the peak voltage.

9 . The welding-type system as defined in claim 1 , wherein the control circuitry is configured to, during the ramp down phase:
control the power conversion circuitry in the current-controlled mode by ramping down an output current of the power conversion circuitry from a peak current; monitor an output voltage of the power conversion circuitry while the output current is decreasing; and in response to detecting that the output voltage satisfies the background transition voltage, control the power conversion circuitry to output the output current based on comparing the output voltage to the background voltage.

10 . The welding-type system as defined in claim 1 , wherein the control circuitry is configured to determining at least one of the peak transition voltage or the background transition voltage to cause wave shaping of the pulse cycle.

11 . A method for pulse welding, the method comprising:
controlling, via control circuitry, power conversion circuitry to output welding-type power in a plurality of pulse cycles, each pulse cycle comprising a background phase, a ramp up phase, a peak phase, and a ramp down phase, wherein the controlling the power conversion circuitry comprises:
during the ramp up phase of the pulse cycles, controlling, via the control circuitry, the power conversion circuitry in a current-controlled mode and switching to controlling the power conversion circuitry in a voltage-controlled mode when a peak transition voltage is reached; and
during the ramp down phase of the pulse cycles, controlling, via the control circuitry, the power conversion circuitry in the current-controlled mode and switching to controlling the power conversion circuitry in the voltage-controlled mode when a background transition voltage is reached.

12 . The method as defined in claim 11 , wherein the controlling the power conversion circuitry comprises controlling the power conversion circuitry based on a peak voltage during the peak phase of the pulse cycles, the method further comprising determining the peak transition voltage based on the peak voltage, wherein the peak transition voltage is lower than the peak voltage.

13 . The method as defined in claim 11 , wherein the controlling the power conversion circuitry comprises controlling the power conversion circuitry based on a background voltage during the background phase of the pulse cycles, the method further comprising determining the background transition voltage based on the background voltage, wherein the background transition voltage is higher than the background voltage.

14 . The method as defined in claim 11 , wherein the controlling the power conversion circuitry in the voltage-controlled mode comprises controlling the power conversion circuitry based on comparing an output voltage of the power conversion circuitry to a target voltage.

15 . The method as defined in claim 14 , wherein the controlling the power conversion circuitry comprises setting the target voltage to be a peak voltage during the peak phases and set the target voltage to be a background voltage during the background phases.

16 . The method as defined in claim 11 , wherein the controlling the power conversion circuitry in the current-controlled mode comprises controlling the power conversion circuitry based on comparing an output current of the power conversion circuitry to a target current.

17 . The method as defined in claim 16 , wherein the controlling the power conversion circuitry comprises ramping up the target current during the ramp up phases and ramping down the target current during the ramp down phases.

18 . The method as defined in claim 11 , wherein the controlling the power conversion circuitry during the ramp up phase comprises:
controlling the power conversion circuitry in the current-controlled mode by ramping up an output current of the power conversion circuitry from a background current; monitoring an output voltage of the power conversion circuitry while the output current is increasing; and in response to detecting that the output voltage satisfies the peak transition voltage, controlling the power conversion circuitry to output the output current b

Assignees

• Illinois Tool Works

Inventors

• Knoener Craig Steven
• Johnson Lucas Charles
• Macmullen Zach W
• Tyler Charles Ace
• Dong Christine

Classifications

• B23K9/0953

  using computing means · CPC title

• B23K9/092 Primary

  characterised by the shape of the pulses produced · CPC title

• B23K9/1006

  Power supply · CPC title

• B23K9/1062

  with computing means · CPC title

• B23K9/133

  Means for feeding electrodes, e.g. drums, rolls, motors · CPC title