Load-frequency control: new perspectives in the open access environment

The paper presents the fundamental concepts of load-frequency control (LFC) in the new context of open access for electrical energy market implementation. LFC is an essential ancillary service for maintaining system security and reliability. Two possible approaches can be considered: the implementation of LFC schemes for centralized, hierarchical and pluralistic control with the derivation and inclusion of autonomy operating conditions for each control area and the adoption of dynamic bilateral contracts between generation and distribution companies. The former approach is the object of this paper. The guidelines of the UCTE Organism have been considered in implementing the LFC schemes. A three area, 73 bus test system has been used for comparing the different LFC schemes. Results are reported and commented also in view of possible indications on accounting of inadvertent interchanges