Arc welding control method and arc welding apparatus

An arc welding apparatus for performing arc welding by repeating a short circuit period and an arc period, the arc welding apparatus comprising:

• a primary side rectifier for rectifying input power;
• a switching unit for converting an output of the primary side rectifier to an alternating current;
• a main transformer for stepping down an output of the switching unit;
• a secondary side rectifier for rectifying an output of the main transformer, and a reactor;
• a driver for controlling the switching unit;
• a welding voltage detector for detecting a welding voltage;
• a welding current detector for detecting a welding current;
• a short circuit/arc detector for detecting a short-circuit state or an arc state based on an output of the welding voltage detector;
• a short circuit controller for controlling a welding output during the short circuit period based on an output of the short circuit/arc detector;
• an arc controller for controlling a welding output during the arc period based on the output of the short circuit/arc detector;
• a timekeeper for measuring an elapsed time from a start of the arc period;
• and
• an electronic reactor controller for controlling an inductance value,
• wherein during the arc period,
• an inductance value associated with a welding output is changed,
• a first inductance value is used, as the inductance value, during a first time interval, the first time interval beginning from a start of the arc period and ending at a predetermined time after the start of the arc period,
• the first inductance value is changed to a second inductance value less than the first inductance value so that the second inductance value is used during a second time interval, the second time interval beginning at the predetermined time after the start of the arc period, and
• constant voltage control is performed during the arc period from a time of the start of the arc period.