Addressing virtual asymmetry of photovoltaic greenhouse with comprehensive AOMH based SWAPP approach

Abstract

Photovoltaic based greenhouse system suffers from the issue of virtual asymmetry despite of considering the photovoltaic modules with symmetric characteristics and matched specifications. Virtual symmetry in such photovoltaic applications results in mismatching losses. This paper aims to address the issue of virtual asymmetry specifically to photovoltaic arrays inclined in opposite directions on a general-purpose hut type structure in a photovoltaic based greenhouse. A prototype model is designed and developed, using a unique add-on modular hardware with its soft switching adaptive power profile approach along with maximum power point tracking implementation to address the issue of degradation of operational efficiency of oppositely inclined PV panels. Due to the proposed synthesis of add-on modular hardware along with soft switching adaptive power profile approach and maximum power point tracking; it is a unique photovoltaic power optimizer, extracting enhanced energy with a stabilized common DC bus. Further, photovoltaic source capacity is matched against varying load from few watts to the full rated load capacity, as per scheduled operations of airflow, photosynthetically active radiation for improved photosynthesis, climate control, and backup battery energy source. The third intangible benefit is minimized thermal loss with an added margin of safe operating area for each power device, resulting in the maximized mean time before failure. As per observation, the additional photovoltaic energy gain under virtual asymmetrical conditions is 8.97–11.21% with overall system efficiency as 64.90–92.04% having a variable load from 10 to 100%. The proposed work may be scaled up for a bigger PV-GH size.