The Research For Variable Polarity Inverter Power Source Application

This paper firstly makes an attempt to introduce the characteristics of variable polarity inverter power source and current research situation in domestic and international welding field. According to the request of the aluminum alloy welding and the development tendency of inverter power source, we propose a new variable polarity inverter power source technology which makes use of the soft switch technology, and systematically study circuit topology and operating principle of soft switch arc welding inverter power source. With the comparing research., a novel soft switch circuit topology which is the full bridge phase shifting zero voltage zero current switching(FB—ZVZCS—PWM) is adopted.Secondly, paper introduces our studies of the build-up configuration and control principle, and presents, as well as, the main power circuit, control circuit, safeguard circuit, display and key circuit, and control software . Furthermore, a detailed description is made to the essential circuit.Full-bridge dual inverter configuration is adopted in main circuit that is supplied by single power source. IGBT (insulated gate bipolar transistor) is comparatively chosen as a switch component to perform energy transfer and power conversion. The main circuit is made up of first stage inverter circuit, high-frequency transformer, and second stage inverter circuit. The design kernel and parameters are discussed at length in this paper where the realization and control of second stage inverter are given emphasis.High performance 32-bit microprocessor LPC2210 is chosen as the core of control system and embedded operating system is adopted by control system who adopts closed-loop and minus-feedback control. The control variable is obtained by microprocessor system after real-time sampling, and current parameters are converted into digital signals. In order to adjust output current, the variable is used to control the major phase shifting chip-UC3875, before constant current output characteristics are acquired, during which PI algorithm is adopted.Finally, this paper carries on the computer simulation research of the soft...