A Variable Step Size Robust Least Mean Logarithmic Square-Based Control Scheme for Improved Power Quality of Grid-Interfaced PV System
Abhisek Parida, Bidyadhar Subudhi
Abstract
Power Quality (PQ) issue has always been a challenge for Grid-Interfaced PV Systems (GIPS). A novel Variable Step Size Robust Least Mean Logarithmic Square (VSS-RLMLS)-based control scheme is thus presented for a GIPS. In the proposed control scheme, the VSS-RLMLS algorithm extracts the fundamental components of the nonlinear load currents accurately even during dynamic conditions which results in generation of accurate reference grid current thus allowing efficient functioning of the Voltage Source Converter (VSC) and delivering high quality power to the grid by mitigating the harmonics of the loads. The performance of the proposed control scheme is validated both in simulation and laboratory developed prototype system with different load and environmental conditions. This VSS-RLMLS control scheme is compared with LMF and variable leaky LMS. It is found that the proposed control exhibits superior PQ performance with least grid current THD.