Effect of Interconnection Lines on the Vulnerability of Power Systems

Electrical interconnections between countries are needed to improve reliability, security, and stability but increase the risk of a disruption in one country propagating to the neighbouring countries, as has already happened in different power supply interruption events in large regional areas. In this article, we demonstrate that power networks increase their vulnerability against cascading failure events when they are weakly interconnected, such as by a single power line. In these cases, the results obtained indicate that it is better to interconnect isolated systems with at least two or more transmission lines. To demonstrate the above, we use the IEEE 24-bus RTS test system network as a benchmark, from which we extract six combinations that are equivalent to 18 different topologies. The results obtained in this article can help to better comprehend the vulnerability of interconnected power systems.