The ANALYSIS OF REDUCTION IN SWITCHING LOSS WITH FEEDFORWARD CONTROL IN GRID-TIED MICRO GRID SYSTEM

Abstract

This paper proposes the simplified pulse width modulation (PWM ) strategy in the bidirectional ac/dc
single-phase converter with the feed-forward control scheme. In this, the number of switching of the
proposed simplified PWM strategy is reduced to one-fourth to that of the unipolar & bipolar PWM. The
feed-forward control scheme is used to achieve better performance of the ac/dc converter in both the
rectifier & inverter mode as compared with the conventional dual-loop control scheme. The simplified
PWM strategy with feed-forward control scheme has higher efficiency than that of the unipolar PWM &
bipolar PWM strategies. Also, the total harmonic distortion is less in this PWM strategy. The simulation
& experiments are carried out to verify the validity of the proposed PWM strategy & control scheme. The
proposed simplified PWM strategy with the proposed feedforward control scheme has lower total
harmonic distortion than the bipolar PWM and higher efficiency than both unipolar and bipolar PWMs.
Furthermore, the proposed simplified PWM operated in the inverter mode also has larger available
fundamental output voltage VAB than both the unipolar and bipolar PWMs. A prototype system is
constructed and the control scheme is implemented using FPGA Spartan-3E XC3S250E. Both simulation
and experimental results verify.