A CONTROLLED SINGLE-PHASE SERIES RESONANT AC CHOPPER

Abstract

A single-phase series-resonant soft-switched ac chopper without auxiliary switches with an efficient control circuit is presented. Basic working principle is series-resonant conversion without any cycloconversion action. Auxiliary switches are absent in this topology. The presented single-phase ac chopper is producing the resonant voltage robes by the action of series resonator with the help of four bidirectional switches. A series of sinusoidal amplitude quasi-sinusoidal pulses synthesized and present at the output as purely sinusoidal waveform following the input voltage waveform. Fre quency modulation with a constant-on time control technique is used in this proposed system. Waveform syntheses for the output sinusoidal voltage are clearly explained with waveforms. A typical design example of single-phase soft-switching ac chopper is simulated to assess the system performance. The power efficiency is improved by using soft switching techniques. The total harmonic distortion is well below 1 % . MATLAB R 2010a version software is used to simulate the model.