Exploration of functional vulnerability of the electricity grid

The complexity of modern day power grid is increasing with penetration of large-scale renewable resources at various levels of the networks. Inclusion of communication networks, to facilitate data transfer for ensuring reliability and security of the power system, with the electricity network extends the complexity to a new scale in a contemporary smart power grid. Any error in the integrated communication network can propagate through the electricity grid initiating large-scale cascading outages. Extensive precautionary measures should be taken in order to avoid such catastrophe. Complex network theory has been very useful in identifying critical components within the system as well as modelling of cascading failures. Complex network theory based percolation methods have been proved to be very useful in assessing power grid vulnerability under random and targeted attacks. In this paper, we extend our network percolation based analysis to explore the functional vulnerability of the existing electricity grid, effect on grid service efficiency, of increasing penetration of renewable energy. Vulnerable regions are identified with a fast computer simulation which helps operators to take quick preventive measures in case of emergency. Various standard IEEE test systems are simulated to test the applicability of the proposed algorithm in a real power system.