Modified NVSSLMS Based Control for Single Stage 3P3W Grid-Interfaced PV System

This paper presents a proposed m-NVSSLMS (Modified New Variable Step Size Least Mean Square) based adaptive control for a single stage, 3P3W (Three Phase Three Wire) grid-tied solar photovoltaic (PV) system. The proposed m-NVSSLMS control has fast convergence, good DC offset rejection, less oscillations and swift dynamic response. Moreover, the fundamental active current component of the load is extricated using this control strategy to generate the reference grid currents for DC-AC converter. This proposed control addresses multifold power quality functions such as grid currents balancing, harmonics minimisation and power factor correction. The solar PV power is extracted using InC (Incremental Conductance) based MPPT (Maximum Power Point Tracking) technique, which feeds the real power to the load and surplus power is infused into the grid. The dynamic results of proposed system is affirmed into the MATLAB\Simulink environment. An experimental prototype is realised in the laboratory to validate the proposed control. Test results show satisfactory responses under various dynamic conditions such as varying solar irradiation levels, load unbalancing. The total harmonic distortions (THDs) of the grid currents are observed well within the IEEE-519 standard.