A Cascaded Dual Buck Half-Bridge Inverter for Efficient Power Flow Control in Grid

Abstract

This paper presents a single phase 7-level half bridge cascade dual buck multilevel grid-tied inverter with both active and reactive power flow control in a wide range under two types of renewable energy. The power flow is controlled by varying the switching pulse of the power semiconductor device used in the half bridge cascade dual buck multilevel grid-tie inverter. The multicarrier sinusoidal pulse width modulation (SPWM) is used by which the power angle can be varied, by changing the switching pulse. By varying the power angle, the voltage and current at the grid side is changed. Active and Reactive power consumed or injected by each unit is depending on the shift angle between the current and modulated voltage in the each single unit of cascade dual buck inverter. Thus by varying the power angle, the power flow can be controlled effectively. The Total Harmonic Distortion (THD) is reduced, when compared with the 11-level cascade H-bridge grid-tie inverter. This is proved by using FFT analysis in MATLAB SIMULINK. The simulation is carried out for both type I and type II system in MATLAB SIMULINK. The experimental results have proved the effectiveness of the designed grid-tie control for both type I and type II system.