| The applications of new conversion techniques,new electronic devices, newmagnetic materials, new software and new control theories is often used ininvert welding power source. It makes invert welding power source welldeveloped those years. Those five things make invert welding power sourcemore mature and more competitive. This paper reviews the development and actuality of arc welding converter,points out the problems and countermeasures in its production in our country. Inthe production of our country their bad reliability, stability and high rate ofmend condition their production, application and further development at all Theinvert welding power source being produced during the graduation design hasmany advantages such as high performance-price ratio, small volume, lightweight, little loss, high efficiency, little static difference, strong reliability, thestrong ability of interference rejection, fine stability, fast dynamic response andcomplete function.. So my work mainly concentrates on such aspects: 1.By course of the switch number and connecting mode the inverterswitch circuit is classified into single port forward, pull, half bridge and fullbridge converter. Single port forward converter has one switch. Pull and halfbridge converter has two switches. Full bridge converter has four switches.Single port forward converter is generally used in small power arc weldingpower source because it has many advantages. Forward topology is widely usedin middle and small power field. There are four kinds of magnetic rest ways.They have both advantages and shortcomings. Double forward is the best way tosolve the magnetic rest question. This way improves the useful power for powersupply and solve the safe working problem. Based on the working principle ofdouble IGBT single port forward converter stimulated, the parameters of maincircuit are elected by theoretic calculation. PSPICE9.0 software is used tosimulate and analyze the circuit. The results verify the design can satisfy exportrequirements and offer theory bases for the successive circuit design. 2.Because main circuit works in the high frequency on-off condition,adopting PWM integrated piece can optimize the design of control circuit andraise real time and the reliability of control circuit. On the foundation ofconsidering various influencing factors fully, state-space averaged law is used toderive the small signal transfer function of control-to-output and the open-loop 72ABSTRACTtransfer function of entire system. Suitable compensation network is selected onthe foundation of overall analysis of compensation network. Entire controlsystem is designed based on making full use of automatic control principle andthe norm of K Factor of Venable .The open loop and close loop of controlsystem are simulated with Matlab. The results of simulation have reached designrequirements. 3. The drive modular EXB841 is selected for IGBT. Lots of theoreticalanalysis and experimental research are carried out towards the drive modularEXB841 for IGBT and the problem that arises in actual application is solved.The suitable peripheral circuit of drive modular is designed for the specificpower module IGBT. The drive circuit makes the shape of drive pulse accordwith requirement and realizes the over-current protection when the current ofcollector of IGBT exceeds the scheduled value. The process of over-currentprotection is as follows: The driving voltage in forward direction on the switchelements is 15v and the closing voltage in reverse direction is -5V．When thecurrent through the collector of the switch elements exceeds the scheduled value90A,the driving voltage added between the gate and the emitter will decreasegradually and reduces to zero after delaying about 10us more or less．So thedriving circuit delays the allowable over current time of the switch elements,decreases the over-voltage at the switch-off time and avo...
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