【摘要】 变极性TIG焊接电源是一种用于铝合金焊接的新型焊接设备,其焊接电流频率、正负半波电流时间和幅值都可以分别独立调节。主电路结构采用2级逆变,前级为全桥逆变式结构,后级为半桥逆变式结构。该电源可实现变极性方波交流、直流、脉冲电流等多种输出。在DCEN向DCEP过渡时采用叠加电流脉冲进行稳弧,小电流时焊接电弧也十分稳定。调节正负半波的幅值、频率及占空比能满足铝及铝合金的焊接工艺要求。更多还原

【Abstract】 The variable polarity TIG welding machine is a kind of new welding power supply used in aluminum alloy.Its current frequency,positive and negative current time and amplitude value are all adjusted respectively and independently.In this research,the structure of the main circuit uses two stages inverter.The forward uses full-bridge inverter and the backward uses half-bridge inverter.The power can output several kinds of welding current such as variable polarity square wave AC,DC and pulse current etc.At the moment when the welding current polarity changed from DCEN to DCEP,the pulse current was added to increase the welding current.So the stable welding arc can be obtained even though under small welding current.The variable polarity power supply can satisfy the welding process of the aluminum and aluminum alloy by adjusting the current frequency,positive and negative current time and amplitude value.更多还原