Effect of switching scheme on the performance of a hybrid solar PV system

The present study develops a hybrid PV system (HyPV) which operates at stand-alone PV mode and grid mode automatically and does not feed power into grid. HyPV operates at PV mode when solar radiation or battery energy is high enough. It switches to grid mode when battery storage is low. The switch scheme from grid to PV mode determines the system performance, including life of battery and switching device, and PV energy generation loss. A switching control parameter (SB, critical charge energy in grid mode) is defined as function of normalized excess PV power generation (eB) and used in the study. A system simulation was carried out to study the effect of switching schemes on long-term system performance. A HyPV system was built and tested to exam the field performance.