This subject will give the idea about following topics .
Flexibility of Electric Power Transmission : The ability to accommodate changes in the electric transmission system or operating conditions while maintaining sufficient steady state and transient margins.
Flexible AC Transmission System : Alternating current transmission systems incorporating power electronic-based and
other static controllers to enhance controllability and increase power transfer capability.
(FACTS) FACTS Controller : A power electronic-based system and other static equipment that provide control of one or more AC transmission system parameters.