Modification of control parameters based on output power

Patent metadata

Field	Value
Publication number	US-9314866-B2
Application number	US-201213480826-A
Country	US
Kind code	B2
Filing date	May 25, 2012
Priority date	May 26, 2011
Publication date	Apr 19, 2016
Grant date	Apr 19, 2016

Abstract

A system and method is provided for calculating a power output and coordinating the reduction of voltage and wire speed. Specifically, provided is a power circuit for generating welding output power, and a control circuit in communication with the power circuit to modify voltage and wire feed speed based on the calculated welding output power.

First claim

We claim:

1. A system for generating a weld, the system comprising:
a power circuit for generating welding output power;
a control circuit in communication with a voltage reducing device circuit of the power circuit to reduce voltage when a calculated welding output power exceeds a predefined power threshold, the voltage reducing device circuit being electrically responsive to the control circuit and reducing a maximum open circuit voltage in response to an open circuit condition being detected between an electrode and a work piece, the control circuit further in communication with a feed mechanism to simultaneously reduce wire feed speed of the feed wire to a weld gun.

2. The system according to claim 1 , wherein the voltage and wire feed speed are reduced proportionally.

3. The system according to claim 1 , wherein the voltage and wire feed speed are reduced according to a predefined relationship.

4. The system according to claim 1 , wherein the reduction in the voltage and wire feed speed are scaled such that a momentary power excess is countered in a manner that mitigates oscillation or periodic variation of voltage.

5. The system according to claim 1 , wherein the reduction in the voltage and wire feed speed are scaled such that a momentary power excess is countered in a manner that mitigates oscillation or periodic variation of wire speed.

6. The system according to claim 1 , wherein the reduction in the voltage and wire feed speed are scaled such that a momentary power excess is countered in a manner that mitigates oscillation or periodic variation of current.

7. The system according to claim 1 , wherein the reduction in the voltage and wire feed speed are scaled such that a momentary power excess is countered in a manner that mitigates oscillation or periodic variation of power.

8. The system according to claim 1 , wherein the reduction in the voltage and wire feed speed are scaled such that a momentary power excess is countered in a manner that mitigates oscillation or periodic variation of one or more of: voltage, wire speed, current or power.

9. The system according to claim 1 , wherein the reduction of the voltage and wire feed speed is based on a nominal power output differential that is correlated to a voltage differential.

10. The system according to claim 1 , wherein the reduction of the voltage and wire feed speed is based on a nominal power output differential that is correlated to a voltage differential and also correlated to a separate wire speed differential.

11. The system according to claim 1 , wherein the control circuit calculates the output power as the product of short term averages of measured weld voltage and current.

12. The system according to claim 1 , wherein the control circuit calculates the output power based on instantaneous measurements of voltage and current.

13. The system according to claim 1 , wherein the control circuit compares the output power to a predefined power threshold and modifies the voltage and wire feed based on the power output.

14. The system according to claim 1 , wherein the control circuit implements a proportional-integral-derivative (PID) control scheme to improve stability or responsiveness of the voltage and wire feed speed.

15. The system according to claim 1 , wherein the control circuit provides a warning of the reduced output power.

Assignees

• Lambert Roger H
• Putnam Geoffrey H
• Victor Equipment Co

Inventors

• Lambert Roger H
• Putnam Geoffrey H

Classifications

• B23K9/0953 Primary

  using computing means · CPC title

• B23K9/10

  Other electric circuits therefor; Protective circuits; Remote controls · CPC title

• B23K9/0956

  using sensing means, e.g. optical · CPC title