Wire Feeding System with H-Bridge of Submerged Arc Welding Based on "Damping Loop"

A "damping loop" control strategy consisting of the external loop of voltage regulation and the internal loop of current regulation and an extra "damping loop" for wire feeding motor of submerged arc welding is proposed. Different dual closed-loop control system is implemented according to varied welding code. The H-bridge bipolar reversible PWM speed regulation system is applied in power circuit, which principles are analyzed. The dual closed-loop block is established and the "damping loop" of the speed-varying wire feeding is also expounded. The good dynamic and static performance of the wire feeding system with this control strategy is verified by actual results.