Lecture
This lecture covers the definition and requirements of system security, focusing on ancillary services necessary for power system operation. Topics include voltage profile, transmission line currents, frequency control, and synchronism. It also discusses angular and voltage instability phenomena, congestion issues, frequency variations, and primary/secondary control mechanisms. The lecture explains the role of ISO in managing system security, the provision of ancillary services through markets, and the different types of contracts involved in ensuring the stability and reliability of power systems.