Abstract-In this paper the functional modeling (FM) method
developed for efficient solution of simulation, planning and
control problems in large power systems and interconnections is
presented. In the first part of the paper outline of the FM method
is given. According to the FM method a power system is
represented by hierarchical model, consisting of systems of
equations of subsystems (lower level) and system of equations of
higher level, in which only boundary variables of subsystems are
present. Next part of the paper is devoted to description of
hierarchical algorithms for solution of power flow , optimization
and stability analysis problems of power systems, based on the
FM method. It is shown in the last part of the paper how
general structure of the FM algorithms and principles of
the FM method are used to form the basis, on which
construction and functioning of distributed control system
assuring optimal operation control in large integrated
electrical power systems is founded.