The we0 known and widely used power system model for the Load
Frequency Control (LFCj problem is extremely linearized and approximated Over the,last
three decades, extensive research efjorts have used such a model as a base for studying
several control schemes in thisjeld Unfortunately, documented reports have proved that
there exist many power systems worldwide sufjering from severe load-/requency
jluctuations. Beside approximation and linearization, the uncertainty of the model
parameters may consrittrte the main reasons of LFC failure. Unlike common control
schemes, this paper presents a Fuzzy Logic-Based Load Frequency Controller. A. Variable
Structure Fuzzy Controller (VSFCj will be developed to suite the power syslem ntodel for
both wide range of parameter uncertainties and different types of disturbances. The
performances of the proposed VSFC are compared with a conventional-LFC for a variety
of system parameters and transient disturbances. This may highlight the effectiveness of
the proposed controller not only solving the LFC problem but also in providing sufficient
damping of the frequency oscillatiows. Another important objective of this paper is that it
presents an easy tutorial to demonstrate the use of readily available computer
sofiare(MATUB, SIMULINK, and Fuzzy Logic Toolboxj in the analysis and design of
Load Frequency Control systems.