Application of real-time voltage security assessment to the Hellenic Interconnected System

The online voltage security assessment methods implemented at the national control centre of the Hellenic Interconnected System, within the framework of the OMASES project funded by the European Union are described. The heart of all computations is a fast time-domain method. Security is analysed with respect to power transfers in critical corridors or power consumption in load areas. Results take on the form of either precontingency secure operation limits, or postcontingency loadability limits, together with various diagnosis tips. Contingency filtering is performed to meet the real-time requirement. Typical results obtained during the test phase of the project are reported.