VSS-DNSE Adaptive Control Algorithm for Enhancing Performance of PV-Grid Interfaced Converter

This paper deals with a 3-phase 4-wire PV (Photovoltaic)-grid connected system feeding nonlinear and unbalanced loads. The f our-leg VSC (Voltage Source Converter) is used to regulate the power flow between the source and load sand to mitigate the power quality (PQ) issues using modified variable step size diffusion normalized sign- error adaptive filtering control algorithm (VSS-DNSEA). The control algorithm is designed to extract the fundamental active current of the load current and to reduce PQ issues using 4-leg VSC as a distributed static compensator (DSTATCOM). A simple and efficient P&O (Perturb & Observe) MPPT (Maximum Power Point Tracking) algorithm is used to utilize the PV array to its maximum capacity and thus achieving effective dynamic and steady state performances. The THD (Total Harmonic Distortion) of the grid current in the system is well maintained within prescribed limits. The control of this system is validated using an experimental prototype and in simulation under different variations.