An arc-welding method in welding by repeating a short circuit and an arc. When the sign of opening of the short circuit is detected, the welding current is reduced from a first current value at the detection of the sign to a second current value, which is lower than the first current value. When the opening of the short circuit is detected, a pulse current having a peak value higher than the first current value is supplied at a plurality of times in the arc period. This suppresses porosities and spatters when galvanized steel sheets are welded.

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.

Systems and methods to start arc welding are disclosed. An example welding-type power supply includes: power conversion circuitry configured to convert input power to welding-type power; and control circuitry configured to: prior to a welding operation, control the power conversion circuitry to stop outputting the welding-type power to a wire electrode; and in response to identifying contact between the wire electrode and a workpiece: control the power conversion circuitry to output an arc starting current to the wire electrode; control a feed motor of a welding torch to retract the wire electrode; control the feed motor to advance the wire electrode based on a first parameter of the welding operation; and control the power conversion circuitry to output the welding-type power to the wire electrode based on the first parameter or a second parameter of the welding operation.

A power supply system includes multiple power supply devices including a first power supply device and a second power supply device that are connected in common to a load. The first power supply device calculates control information for controlling voltage or current to be output to the load and source information for obtaining the control information, and controls the output to the load based on the calculated control information while transmitting the source information to the second power supply device. The second power supply device receives the source information transmitted from the first power supply device, calculates control information based on the received source information, and controls the output to the load while detecting current to be output from itself to the load and transmitting current information to the first power supply device. The first power supply device receives the current information and calculates control information and source information based on the received current information and the current and voltage detected by itself.

A welding power supply device includes an inverter for converting DC power into AC power outputted to a welding load, and a voltage circuit for superimposing a restriking voltage on an output to the welding load when the polarity of output current of the inverter switches. The voltage circuit includes a restriking capacitor charged with the restriking voltage, a charging circuit to charge the capacitor with the restriking voltage, and a discharging circuit to discharge the voltage in the capacitor. The charging circuit includes a DC power supply and a booster to boost DC voltage from the DC power supply. The charging circuit charges the restriking capacitor in first and second states. In the first state, the DC voltage from the DC power supply is directly applied to the restriking capacitor. In the second state, DC voltage boosted by the booster is applied to the restriking capacitor.

A welding power supply device includes an inverter for converting DC power into AC power outputted to a welding load, and a voltage circuit for superimposing a restriking voltage on an output to the welding load when the polarity of output current of the inverter switches. The voltage circuit includes a restriking capacitor charged with the restriking voltage, a charging circuit to charge the capacitor with the restriking voltage, and a discharging circuit to discharge the voltage in the capacitor. The charging circuit includes a DC power supply and a booster to boost DC voltage from the DC power supply. The charging circuit charges the restriking capacitor in first and second states. In the first state, the DC voltage from the DC power supply is directly applied to the restriking capacitor. In the second state, DC voltage boosted by the booster is applied to the restriking capacitor.

As a conventional problem, welding on surface-treated material, such as a zinc-coated steel plate, considerably generates air holes including blowholes and also generates lots of spatters. Present invention provides a method of controlling arc welding performed in a manner that a short-circuit period, in which a short circuit is generated between a welding wire and an object to be welded, and an arc period, in which an arc is generated after release of the short circuit, are repeated alternately. According to the method, welding current is increased from an arc-regeneration-before current to a first welding current at a detection of release of the short circuit such that an increase gradient of the welding current becomes not less than 750 A/msec. This suppresses generation of air holes and spatters in welding work on a surface-treated material, such as a zinc-coated steel plate.

As a conventional problem, welding on surface-treated material, such as a zinc-coated steel plate, considerably generates air holes including blowholes and also generates lots of spatters. Present invention provides a method of controlling arc welding performed in a manner that a short-circuit period, in which a short circuit is generated between a welding wire and an object to be welded, and an arc period, in which an arc is generated after release of the short circuit, are repeated alternately. According to the method, welding current is increased from an arc-regeneration-before current to a first welding current at a detection of release of the short circuit such that an increase gradient of the welding current becomes not less than 750 A/msec. This suppresses generation of air holes and spatters in welding work on a surface-treated material, such as a zinc-coated steel plate.

Systems and methods for auto-tuning a MIG welding process are disclosed. A welding-type power supply may include a power conversion circuitry configured to convert input power to welding-type power; and a controller configured to control the power conversion circuitry based on a plurality of operating parameters. The operating parameters may include an inductance parameter, a slope parameter, or a wet time parameter. During the welding process, in order to control the power conversion circuitry, the system may measure an output from the power conversion circuitry, and may update the inductance parameter, the slope parameter, or the wet time parameter.

To stabilize a growth state of a droplet during an electrode negative polarity peak period in consumable electrode AC pulse arc welding. In an AC pulse arc welding control method for controlling welding which is performed by feeding a welding wire, and applying an electrode negative polarity base current during an electrode negative polarity base period, then applying an electrode negative polarity peak current during an electrode negative polarity peak period, and then applying an electrode positive polarity current during an electrode positive polarity period, to repeatedly apply these welding currents, the electrode negative polarity peak period includes a rising period Tu, a peak period Ta, and a falling period Td, a time ratio of the peak period Ta to the electrode negative polarity peak period is less than 20%, and the falling period Td is a period twice or more longer than the rising period Tu.