Research For APFC Of Three-phase High Power Arc Welding Inverter

The applied universality along with various electric power electronics, a pollution of harmonic of the charged barbed wire net is gradually serious, an interference of harmonic has become the electric power system in one of the key problems. This literary grace with an active method for repress, commutated the machine to carry on the thorough research to the high power factor, the point analyzed three mutually three switch APFC controllers. That system has the advantages, such as good importation function, higher power factor and the low electric current mutation etc.In this dissertation significances of Active Power Factor Correction (APFC)are clarified. A comprehensive review of the recent development and principles of various topologies and control schemes in active PFC.The analysis and features of the control schemes in the APFC are proposed, a new nonlinear control technique is proposed, that is One Cycle Control. the future promising of control schemes are given. Based on the one-cycle control concept, a generaland novel APFC controller is proposed for three-phase rectifiers in this thesis. The principles of the PFC controller are showed particularly. The control technique is applied to control the duty ratio d of the switch in real time such that in each cycle the averaged of the switch in real time such that in each cycle the average value of the chopped waveform at the switch rectifiers output is exactly equal to the control reference, unity fundamental power factor and low current distortion can be achieved. The proposed controller does not require multipliers to scale the current reference according to the output power level, consists of one integrator with reset along with logic IC and linear components. It simplifies the structure and complication of circuits and is easy to realizeThis text is in main electric circuit of APFC the adoption double to can control the switch, commutate the bridge mutually the electric circuit of Boost put at three of importation carry, adopt the single period control electric circuit, apply in three mutually big power wildings go against to change the power supply of the net side electric current harmonic wave repress. Moreover, for raising the whole efficiency of electric circuit and reducing the switch to exhaust, still made use of the soft switch...