Digital control of double- pulsed gas metal arc welding machine

• Published in: 2009 IEEE 6th International Power Electronics and Motion Control Conference pp. 2573 - 2576
• Main Authors: Deshang Sha, Xiaozhong Liao
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.05.2009
• Subjects: Buck converters; DC-DC power converters; Digital control; Digital signal processing; Pulse width modulation; Pulse width modulation inverters; Signal generators; Space vector pulse width modulation; Welding; Wire
• DOI: 10.1109/IPEMC.2009.5157839
• ISBN: 1424435560; 9781424435562

In this paper, a fully digitalized phase-shifted full-bridge PWM gating signals generation based on symmetrical carrier is proposed. To make wire feeder vary synchronously with the output current of DC/DC converter, double closed loop control is implemented by DSP. Besides, to improve the dynamic response of wire feeder, power stage for the motor is made up of a buck converter cascaded with a full-bridge inverter . A triple closed loop control model with full digital control is also presented to achieve double-pulsed GMAW process. The control model also contains stick-out length compensation, arc length regulation and instantaneous current control. Flexibility and reliability of the proposed control strategy for DP-GMAW implemented by two DSPs are validated by welding experimental results of 20 kW prototype.