Delta modulated cyclo-inverter

Delta modulation (DM) is simple and has characteristics advantageous to the operation of cyclo-inverter. Analysis and implementation of delta modulated switching is presented in this paper both for cyclo-inverter as well as for cyclo-converter. Simulation results are shown for single-phase to single-phase centre tapped transformer configuration using SIMULINK software. This confirms a validity of the delta modulation technique for step up as well as step down operation. It has been found that total harmonic distortion (THD) is low for modulation index lying from 0.75 to 1.5. Any further increase or decrease in modulation index increases the harmonics in the converter. The output improves with increasing sampling frequency above 2 KHz where THD has been found to be as low as 4% for cyclo-inverter and 2% for cycloconverter.