Three to single phase buck-boost regulated high power quality Cycloconverter

In this paper, a new approach to design a good power quality three to single phase Cycloconverter regulated and controlled by Buck-Boost converters differentially connected across the load has been proposed. The proposed Cycloconverter improves Power Quality by reducing Total Harmonic Distortion (THD) of input line current, input Power Factor (Pf) and overall Efficiency (η) of the power conversion. Traditional twelve thyristor (SCR) cycloconverter has high THD (19% and above) and has only two quadrant operation on V~f plane. The proposed Cycloconverter has a lower THD (15% and below), requires only eight switches and it has the advantage of four quadrant control of voltage and frequency. Simulation has been performed in PSIM and Simulink for resistive and inductive loads with Back-emf. Open loop sliding Technique is applied to ensure good power quality at desired performance. Details of Operation and circuit performance is presented in this paper.