Modified sinusoidal pulse-width modulation operation technique of an AC-AC single-phase converter to optimise the power factor

摘要

A modified sinusoidal pulse-width modulation (sPWM) switching technique is suggested for the operation of a power electronic converter to control the power and to optimise the power factor (PF). The idea is to shift the delayed grid current to the grid voltage, through a modification of the classical sPWM converter switching technique in order to improve the PF. In this way, the decrease in the phase angle between the fundamental current harmonic and the voltage at the grid side is feasible, and consequently, the use of compensation capacitors can be avoided. Consequently, the PF optimisation as well as an improvement in the power efficiency can be achieved. The effect of the proposed switching technique on the PF and the power efficiency is investigated via simulation using the software Matlab/Simulink as well as through appropriate experiments. For the experimental investigation, a prototype has been designed and constructed in the laboratory. The proposed modification of the sPWM converter operation has been applied in a single-phase AC-AC PWM converter supplying a resistive-inductive load.