A PWM & HYSTERESIS CURRENT CONTROL BASED PFC TECHNIQUE IN AC TO DC CONVERSION

D.C. motors are seldom used in ordinary applications because all electric supply companies furnish alternating current However, for special applications such as in steel mills, mines and electric trains, it is advantageous to convert alternating current into direct current in order to use D.C. motors controlled by power electronic apparatus. The reason is that speed/torque characteristics of D.C. motors are much more superior to that of A.C. motors. The need for solid-state ac-dc converters to improve power quality in terms of power-factor correction (PFC), reduced total harmonic distortion at input ac mains, and precisely regulated dc output have motivated the proposal of several topologies based on classical converters such as buck, boost, and buck-boost. Additionally, novel control techniques dedicated to PFC have also been introduced, motivating the manufacturing of commercial integrated circuits to impose sinusoidal currents in the front-end stage of switch-mode converters. In this paper use one PFC converter with DC machine drive draws a current which is purely sinusoidal. Merits of this converter include higher power density, less harmonic control contents, unity power factor & unidirectional power flow. The simulation results are obtained using MATLAB/SIMULINK software