Power quality improvement in single phase grid tied solar PV-APF based system using improved LTI-EPLL based control algorithm

This paper deals with an improved LTI-EPLL (Linear Time Invariant-Improved Enhanced Phase Lock Loop) based control algorithm for a single-stage solar PV (Photovoltaic) power generating system (PVGS) with the power quality improvement. The proposed PVGS comprises of a PV array, a single phase voltage source converter (VSC), a nonlinear load and the grid. The VSC is used as a link between the PV array and the grid. The VSC provides the multifunctional capabilities in PVGS. An improved LTI-EPLL based algorithm is used for harmonics mitigation, power factor correction and load compensation in proposed PVGS. The PVGS preserves its capabilities of compensating harmonics on cloudy days (i.e. PV power, PPVis present). It also provides this facility in the night time (PPV=0) with utilization of available power sources. Test results have been analyzed and the response of PVGS with an improved LTI-EPLL based algorithm under varying environmental conditions, load changes and different mode changes conditions.