Abstract
Load frequency control or automatic generation control is one of the main operations
that take place daily in a modern power system. The objectives of load frequency control are
to maintain power balance between interconnected areas and to control the power flow in the
tie-lines. Electric power cannot be stored in large quantity that is why its production must be
equal to the consumption in each time. This equation constitutes the key for a good
management of any power system and introduces the need of more controllers when taking
into account the integration of renewable energy sources into the traditional power system.
There are many controllers presented in the literature and this work reviews the traditional load
frequency controllers and those, which combined the traditional controller and artificial
intelligence algorithms for controlling the load frequency.