PWM和PFM混合调制逆变TIG焊电源控制特性的研究

A Study on Control Characteristic of Inverting TIG Welding Power Source with Double Modify of PWM and PFM

在薄板小电流电弧焊的过程中，影响焊接质量的一个重要因素就是电弧的稳定性．本文介绍一种用于薄板TIG焊的逆变电源，该电源的输出控制采用强的非线性调节环节与弱的PID环节相结合处理反馈信号并以PWM和PFM混合调制的方式来进行．输出滤波电感采用比较独特的摆动电感结构，提高了电弧的稳定性．电源的引弧为PFM降频调制的接触引弧方式，引弧过程可靠且不烧损钨极．通过对高频道变脉冲的低频调制达到控制线能量的目的．

During welding thin plates with less arc current, the arc stableness is an important factor to affect the welding quality. This paper introduces a inverting TIG arc welding power source used in welding thin plates whose output characteristic is controlled by a power non-lineal unit cormected with a general PID unit based on the controlling way of PWM and PFM. The special helps improving arc stablness. Its short-circuit shoing arc is reliably controlled by a special method of PFM with less frequency and avoids overheating the tungsten electrode. The welding line energy is decided by the high frequency pulse modified by the low frequency one.