Modified EPLL based control to eliminate DC component in a grid interfaced solar PV system

In a grid interfaced SPV power generation system, the DC component is normally present in the input signals due to faults in the system or measurement limitations. This DC component produces low frequency oscillations and saturation of magnetic components. In this paper, a modified enhanced phase locked loop (MEPLL) control algorithm is proposed to eliminate such DC component. This MEPLL control algorithm is used to extract fundamental component from input signals and further the active and reactive power components of the load currents are estimated in order to generate reference currents to control 3-leg voltage source converter (VSC) used in grid interfaced SPV generating system. The performance of proposed SPV generating system is simulated using MATLAB/Simulink and sim-power system toolboxes. Simulation results of proposed system are demonstrated for improved power quality of a three-phase 3-wire distribution system for load balancing, harmonics elimination, neutral current compensation, voltage regulation and power factor correction.