A Direct and Indirect Current Control Schemes for a Single-Stage Grid-Connected PV System

In this work, a comparative analysis of direct current control (DCC) and indirect current control (ICC) schemes has been discussed for a single-stage grid-connected PV system. The use of a VSI in a single-stage grid-connected PV system gives rise to the issue of switching ripples in the grid current which yields increased THDs in grid current. Therefore, it is imperative to develop a suitable current control scheme for appropriate switching of the VSI. Both DCC and ICC schemes are simulated in MATLAB/Simulink environment. The results obtained indicate that the ICC scheme yields lesser THDs in grid current than the DCC scheme. The THD yielded by indirect current control scheme remains within the acceptable limits given by IEEE-519 standards.