International Journal of Engineering and Technology

The injection of good quality current into the grid is always prominent task for the grid-tied inverters. The usage of classical Proportional Integral (PI) controllers, though, dominates in all process control industry, they fail to track periodic signals like sine waves without DQ transformations. To eliminate the usage of DQ coordinates and also the steady state error in sinusoidal signals tracking, the sinusoidal error input feeding to the PI controller is divided into N-step shaped single. The value of N is decided by the switching frequency used in the controller loop, to eliminate the dead-zone effect of inverter switches. Mathematical analysis and extensive simulation results are proved that elimination of steady state error and injection of good quality of sinusoidal current when compared to Conventional PI controller. The THD analysis clearly approves the outperformance of the modified PI controller over the conventional one.