An arc welding system of a consumable electrode type comprises: a wire feeding device that feeds welding wire from a wire feeding source to a welding torch; and a power supply device that supplies electric power between the welding wire fed to the welding torch and a base material, the system being configured to weld the base material by arc generated by the supplied electric power. The wire feeding device is provided with: an intermediate wire feeding source that is disposed between the wire feeding source and the welding torch and is configured to temporarily accommodate the welding wire fed from the wire feeding source and to feed the accommodated welding wire to the welding torch; a pull-out feeding part that feeds the welding wire at the wire feeding source to the intermediate wire feeding source; and a push-out feeding part that feeds the welding wire accommodated in the intermediate wire feeding source to the welding torch.

In an arc start control method for forward and reverse feed arc welding in which forward and reverse feed control of alternately switching a feed speed Fw of a welding wire between a forward feed period and a reverse feed period is performed to generate a short circuit period and an arc period to perform welding, at arc start, a pulse period Tp during which a pulse current is energized for a plurality of number of times is provided, and thereafter forward and reverse feed control is started from forward feed period of the welding wire. During the pulse period Tp, a forward feed speed Fp of the welding wire is set so that the arc period is continuous. In addition, the forward feed speed Fp is changed based on a time length of pulse period Tp and/or a value of a welding voltage Vw during pulse period Tp.

In an arc start control method for forward and reverse feed arc welding in which forward and reverse feed control of alternately switching a feed speed Fw of a welding wire between a forward feed period and a reverse feed period is performed to generate a short circuit period and an arc period to perform welding, at arc start, a pulse period Tp during which a pulse current is energized for a plurality of number of times is provided, and thereafter forward and reverse feed control is started from forward feed period of the welding wire. During the pulse period Tp, a forward feed speed Fp of the welding wire is set so that the arc period is continuous. In addition, the forward feed speed Fp is changed based on a time length of pulse period Tp and/or a value of a welding voltage Vw during pulse period Tp.

A digitized variable-polarity welding power source based on SiC IGBT, comprising a main circuit and a control circuit. The main circuit comprises a three-phase rectifying filter circuit, a SiC IGBT primary inverter circuit, a high-frequency transformer, a SiC ultrahigh-frequency rectifying filter output circuit, a SiC IGBT secondary inverter circuit and a high-voltage arc stabilizing circuit which are sequentially connected. The control circuit comprises a controller and a power supply control module, and a digitizing tablet, a SiC primary inverter driving module and a SiC secondary inverter driving module which are in connection with the controller via signals.

A digitized variable-polarity welding power source based on SiC IGBT, comprising a main circuit and a control circuit. The main circuit comprises a three-phase rectifying filter circuit, a SiC IGBT primary inverter circuit, a high-frequency transformer, a SiC ultrahigh-frequency rectifying filter output circuit, a SiC IGBT secondary inverter circuit and a high-voltage arc stabilizing circuit which are sequentially connected. The control circuit comprises a controller and a power supply control module, and a digitizing tablet, a SiC primary inverter driving module and a SiC secondary inverter driving module which are in connection with the controller via signals.

An arc welding control method includes: feeding a welding wire; and repeating a short-circuit period and an arc period, where the arc period includes a first arc period and a second arc period following the first arc period. A welding current is applied using constant current control during the first arc period, and the welding current is applied using constant voltage control during the second arc period. The first arc period is set to an electrode-negative polarity, and a period other than the first arc period is set to an electrode-positive polarity.

In an arc welding control method for controlling welding in which a material of a base material is a galvanized steel sheet, a feed speed of a welding wire is alternately switched between a forward feed period and a reverse feed period, and a short circuit period and an arc period are repeated, during the arc period, a first arc period Ta1 during which a first arc current Ia1 is applied, a second arc period Ta2 during which a second arc current Ia2 is applied, and a third arc period Ta3 during which a third arc current Ia3 is applied are switched over time, and it is controlled so as to be Ia1>Ia2>Ia3. Constant voltage control is performed during the second arc period Ta2, and constant current control is performed during the first arc period Ta1.

A system for controlling a weld-current in an arc welding apparatus for short arc welding comprising a current regulator included in a voltage feedback loop from a power supply to a welding electrode and a ramp generator arranged to provide current ramps during a short circuit phase at said welding electrode.

A system for controlling a weld-current in an arc welding apparatus for short arc welding comprising a current regulator included in a voltage feedback loop from a power supply to a welding electrode and a ramp generator arranged to provide current ramps during a short circuit phase at said welding electrode.

An arc welding control method for controlling welding in which a material of a welding wire is aluminum or an aluminum alloy, and a feed speed Fw of the welding wire is alternately switched between a forward feed period and a reverse feed period to repeat a short circuit period and an arc period, a welding current Iw is controlled so that an average value of maximum values of the welding current Iw during the short circuit period is 150 A or less. A reverse feed peak value Wrp during the reverse feed period is set so that an average value of time lengths of the short circuit period is 7 ms or less. Accordingly, the current value can be reduced when the short circuit is released and the lengthening in the short circuit period can be prevented, so that the spatter generation amount can be reduced.