A novel composite control strategy for plasma cutting power supply based on arc control

作者：Sun Qiang^*; Chen Long; Chen Guitao; Wang Huamin

来源：Transactions of the China Welding Institution, 2014, 35(3): 71-75.

• Arc control
• Composite control
• Composite control strategy
• Control requirements
• Feed-forward compensator
• Plasma cutting
• Rapidity and stabilities
• Static characteristic

This paper analyzes static characteristics of plasma arc with the derivation of plasma arc mathematical model according to the application of low-frequency (LF) pilot arc technology in the plasma cutting power supply, and integrates with the control requirements in low-frequency (LF) pilot arc, arc transferring and arc energy transferring, and proposes a novel composite control strategy. In order to meet the power's control requirements of rapidity and stability with the load of low-frequency (LF) pilot arc, the inner loop of this strategy builds up voltage loop composite control with feed-forward arc voltage and feedback arc voltage, and the current outer loop controls the energy of plasma arc, forming a control method of feed-forward composite control of double closed-loop. Simulations and experiments were given to verify that the mentioned control strategy not only improved system's stability and robustness, but also had excellent dynamic responsibility. The power had well non-liner resilience, meeting requirements for plasma cutting power supply.

• 出版日期2014