The Study On A Single-ended Forward Zero Voltage Transition Arc Welding Power Supply Inverter

Arc welding inverters have many good qualities, such as small volume, lightness, high efficiency and dynamic response. So they are recognized as the most prospective welding power supply in the welding field. This paper reviews the history and present situation of welding power supply and points out that capacitive turn-on loss,inductive turn-down loss, big tutn-on loss, diode recovery questions are four unsolvable questions of traditional welding power supply. The soft-switching technique is the best way to solve the above four questions. It uses resonant phenomenon to make main switch turn on or turn down under the situation of zero voltage. This technique solves the problem of low reliability for main switch(IGBT) and reduces the switching loss greatly. At present,the research of Soft-switching converter has been a direction of power supply development and is paid much attention. This paper elaborates deeply on control idea and theory. Based on these theories, a set of control circuit has been devised. Applications of these theories improve the dynamic properity and reliability of power supply. It not only greatly reduces the amount of the components selected but improves the reliability of the power supply because of adjustment and improvement on the control circuit. Because main circuit works in the high frequency on-off condition, adopting PWM integrated piece can optimize the design of control circuit and raise real time and the reliability of control circuit. On the foundation of considering various influencing factors fully, state-space averaged law is used to derive the small signal transfer function of control-to-output and the open-loop transfer function of entire system. Suitable compensation network is selected on the foundation of overall analysis of compensation network. Entire control system is designed based on making full use of automatic control principle. The open loop and close loop of control system are simulated with Matlab. The result of simulation has reached the requirement of the design. Forward topology is used widely in middle and small power field. There are four kinds of magnetic reset way. Double forward technique is the best way to solve magnetic reset question. This way improve the useful power for power supply and solve the safe-working problem under the situation of soft-switching for large power...