Exploration and investigation of potential precursors to unintentional islanding in grid-interfaced solar photo voltaic systems

Abstract

The concept of distributed energy is becoming integral to the smart grid paradigm. Cleaner and renewable sources like solar energy, in the form of photo voltaic systems, are being integrated at the lowest level of the power grid - the distribution network. However rising penetration of such distributed sources may cause operational issues like unintentional islanding which remains a concern among utilities. This work tries to create and analyze situations which are expected to develop frequently in the high penetration scenario and explore their impacts on possibility of unintentional islanding. Dynamic simulations are run for a modified IEEE feeder and potential precursors to accidental islanding are identified. Load-photo voltaic interactions and gridside disturbances are the situations that cause unique anomalous behaviour in grid-side current. Experimental observations on laboratory hardware also showcase similar behaviour albeit on a simpler network containing a different load model. Simulations are run again to reproduce the experimental observations. Such approach intends to create a predictive framework for islanding detection in real time.