Improved Gamma type Y-source inverter for rooftop PV based V-G applications

Abstract

Renewable energy generation is inherently unpredictable and may contain unacceptably significant variations. In particular, high solar photovoltaic (PV) penetration makes it difficult for utility companies to coordinate production and consumption on the grid. PV generation with an energy storage element flattens the duck curve and eliminates the PV curtailment during the mid-day hours. This paper proposes a novel improved Gamma (Γ-) type Y-source inverter for rooftop photovoltaic (PV)-grid applications with battery storage ability. The proposed inverter can maintain high voltage gain even under partial shading conditions, where the PV voltage at the maximum power point is far away from the open circuit PV voltage. The proposed inverter allows plant owners to charge the battery from PV source during low-peak loading hours and can reduce power import during high-peak loading hours (or) export the excess power to the distribution grid, which increases the return on investment. The operation of the proposed inverter is analysed in three modes (a) stand-alone operational mode without battery, (b) stand-alone operational mode with battery, and (c) stand-alone operational mode with PV and battery. A scaled-down laboratory prototype of 70 W is created to test the functionality of the proposed inverter and validate the simulation results. Experiments show that the proposed Improved Gamma type YSI can generate a boosted ac voltage using independent PV and battery sources, as well as their combination. © 2022 Elsevier Ltd