ABSTRACT
This chapter presents inherent concepts, activities, and tools for power system operation within the context of modern energy management systems. There will be special emphasis on tools for correcting transmission network problems and its optimization. The chapter also presents a classification of the power system state as a function of its degree of security. It provides contingency analysis techniques for determining the security degree of the power system constituting the base of many real-time operation or planning studies. The chapter explores the optimal power flow problem, with different examples of the operation problems formulated as constrained optimization problems. It discusses key power system issues associated with transmission network open access. If system security is given priority, preventive control enters the scene to drive the system to a secure state. When the system is in a normal, secure state, all operational limits are fulfilled and the accorded security criteria is achieved.
