METHOD FOR CONTROLLING OUTPUT OF THYRISTOR PHASE CONTROL ARC WELDING POWER SOURCE

PROBLEM TO BE SOLVED: To prevent the phenomenon that, in a thyristor phase control arc welding power source, since the ripple of output current is large, electron reactor control for optimizing the change rate of the output current malfunctions. SOLUTION: Regarding the method for controlling the output of a thyristor phase control arc welding power source, output current (i) is detected, the change rate in the detected value (id) of the output current is calculated, the output current change rate Bi=di/dt is multiplied by an amplification factor Lr to calculate current change rate amplification value Bia=Lr×Bi, the current change rate amplification value Bia is subtracted from predetermined output voltage set value Er to calculate voltage control set value Ecr=Er-Lr×di/dt, and output control is performed in such a manner that output voltage E is made almost equal to the voltage control set value Ecr, the output current change rate Bi is calculated by the change rate of the current value at prescribed parts in the ripple cycle of the output current (i). COPYRIGHT: (C)2007,JPO&INPIT