Parallel MPPT for PV based residential DC Nanogrid

Abstract

Solar Photovoltaic (PV) based DC Nanogrid has simple installation, higher conversion efficiency, low losses, high reliability, remote electrification and safety. In this paper, a parallel maximum power point tracker (MPPT) for residential and commercial DC Nanogrid has been discussed. The proposed MPPT is connected in parallel with PV source & load. It supplies the difference between the load power demand and the maximum PV power generation. The MPPT is realised using a grid-source power converter (GSC) which operates in closed loop fashion. For accurate tracking of maximum power point, PI based incremental conductance (PI-IC) algorithm has been used. To reduce the computational load on digital controller, the ratio metric part of the algorithm has been replaced by the product of the input quantities. The proposed parallel MPPT has been validated by experimental results and given in the paper.