Research On Control System Of Inverted SAW

Submerged Arc Welding(SAW),one of the earliest welding process,is widely used in modern industries as welding technique is developing towards automation and intelligence. The welding quality is affected by the stability of arc length in the welding process. The arc length is mostly changed by the stability of the welding current source and wire feed speed regulation. In this paper, these two aspects which are important to the quality of SAW are on a research.SAW arc welding and arc welding wire melting rate model are established based on the analysis of the electrical principles, and mathematical model of SAW is established. The constant current characteristics of SAW and the stability of the arc length are realized by using model reference adaptive control adjusting the voltage and wire feed rate. The system is analyzed using ultra-stability method in the design of model reference adaptive control law. The realization problem of SAW model reference adaptive control is solved. The SAW hardware and software using the core of 80C196KC are designed according to the requirements. The hardware whose anti-interference performance is considered includes the main circuit and control circuit. The main circuit consisted of input rectifier, inverter, high frequency transformer and output rectifier circuit. The control circuit involves the sampling circuit, PWM control circuit and wire circuit. The software has two parts including sub-circuit constant-current characteristics and control circuits.Matlab simulation is carried out with the distractions and the result was compared to the correspondance on the PID control algorithm. The results show that model reference adaptive algorithm can guarantee the constant current characteristics and the stable arc length, better effect can be ensured.