The Design For Variable Polarity TIG Welding Electrical Power System

The article has consulted the massive domestic and foreign literature material, analyzed the development survey,the tendency and the research progresses of the Variable Polarity TIG welding electrical power,and proposes one kind of the double contravariant electric circuit structure of the variable polarity TIG welding,namely the main power source circuit used two levels to invert,the frist inversion selectes the IGBT entire bridge inversion method,the second inversion is also the IGBT entire bridge type inversion structures.This article thoroughly research the main variable polarity TIG welding circuit principle of work,and carries on the design of the main circuit parameter.Moreover,using the MATLAB software carry on the modelling,the simulation.to the Variable Polarity TIG welding electrical power system,Its simulation profile and experimental profile contrast are basic same.The main circuit,control circuit and driving circuit of the developed device was studied and designed in the paper.The control system uses the PWM pattern control mode, the frist invertor uses the PWM3525 control circuit PWM special-purpose actuation chip M57962L to carry on the actuation,the second invertor uses the 555 control circuit, through the control pulse and light pair TLP250 actuates carries the second contravariant electric circuit.In addition,but also introduces the protection circuit.Compared with various power devices,IGBT were employed as the switches of two inverters.Soft -starting circuit is designed to overcome the surge current for protecting main switches. Test waveforrns were measured when was installed and adjusted.Every waveform was analysed in the paper.The results of test show that the developed the Variable Polarity TIG welding electrical power can output stable intermittent alternative square wave pulses,its every performance index can satisfy the design request.The test result indicates the Variable Polarity TIG welding electrical power system that this article develops is stable reliable,also output electric current in DCEP period peak-to-peak value I_P and in DCEN period peak-to-peak value In,frequency and plus and minus half-wave breakover are all independent adjustable,satisfies the aluminum and the aluminum alloy welding craft demand.So it is one kind of ideal welding power source.