ANALYSIS AND DESIGN OF A ROBUST COORDINATED AVR PSS/

A robust coordinated AVR/PSS, called the ''Desensitized Four Loops Reg ulator'' (DFLR) has been recently designed using the ''desensitized co ntrol'' theory. Its synthesis method (which can be applied to other pr oblems than excitation control) and ifs structure are detailed in this paper. It is a state feedback controller including an integrator on t he regulation error. This structure, although it is well known in the control community, is not usual for excitation control of generators ( except in France). Hence, in order to make this approach more widely a pplicable in an industrial point of view, this controller is put, usin g approximations, in the standard AVR+PSS structure IEEE ST1A+PSS1A. T he resulting AVR+PSS is proven to have a good performance, in particul ar for damping inter-area oscillations.