PWM和PFM混合调制逆变TIG焊电源控制特性的研究

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析。通过对高频逆变脉冲的低频调制达到控制线能量的目的

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

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.