Suppressing the side effect of the grid background harmonics on grid inverter with selective harmonic elimination PWM

Due to the presence of the low-order background voltage harmonics in the grid, it will cause higher current harmonics in the AC side of the grid inverter with Selective Harmonic Elimination PWM (SHEPWM). Therefore the grid inverter with traditional SHEPWM has not prevailed since it is unable to overcome the background harmonics of the utility and satisfy the power quality requirement. In this paper, the effect of the background harmonics is analyzed. Then a control scheme to suppress the grid background harmonics effect on grid inverter with SHEPWM is presented. Finally the feasibility of this method is verified by experiment.