WELDING OR ADDITIVE MANUFACTURING POWER SUPPLIES WITH REAL TIME RESISTANCE MONITORING OF AN ARC WELDING CIRCUIT ; WELDING OR ADDITIVE MANUFACTURING SYSTEM WITH SUCH POWER SUPPLY

摘要

A welding or additive manufacturing power supply includes output circuitry configured to generate a welding waveform, a current sensor for measuring a welding current (I_S) generated by the output circuitry, a voltage sensor for measuring an output voltage of the welding waveform, and a controller operatively connected to the output circuitry to control the welding waveform, and operatively connected to the current sensor and the voltage sensor to monitor the welding current (I_S) and the output voltage. A portion (302) of the welding waveform includes a controlled change in current from a first level (308a) to a second level (310) different from the first level (308a). The controller is configured to determine a circuit inductance from the output voltage and the controlled change in current (I_S), and further determine a change in resistance of a consumable electrode in real time based on the circuit inductance.