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Wed., May 12, 2010, 10 a.m. Osborne Conference Room
(ECSS 3.503)

 

 

 

 

 

 

 

 

 

 

 EE seminar series

“Applications of Passivity-based Control to Electric Drives,
Power Converters and Power Systems”

Dr. Romeo Ortega, Laboratoire des Signaux et Systemes

Abstract
Passivity in physical systems is a restatement of energy balancing and therefore is a ubiquitous property in engineering applications. One important property of passive systems is that, under some weak conditions, their unique equilibrium state is stable. Passivity-based control (PBC) was introduced 20 years ago as a controller design technique that achieves stabilization rendering the system passive with a desired energy function, i.e., with a minimum at the desired equilibrium. PBC is now a well-established procedure with many practical applications to diverse physical systems.

In this talk we review some of the major developments of PBC in electrical systems, which include: (i) The proof that PBC applied to induction motors yields, as a particular case, the industry standard field-oriented control, providing a solid theoretical justification to this popular technique. (ii) Application of PBC to other machines, including permanent magnet and doubly-fed, are also reviewed. (iii) For a large class of power converters PBC in its incremental passivity version allows identification of suitable “output signals,” with respect to which a classical PI controller can be applied with guaranteed stability properties. Interestingly, in the particular case of three-phase rectifiers, this output turns out to be the one used in the heuristic – but widely used – Akagi’s PQ instantaneous power controller. Adaptation, to handle the case of unknown loads, can be easily added to the resulting PI. (iv) For generator field excitation control in transient stability problems, PBC effectively increases the critical clearing time with respect to standard power system stabilizers.

Besides a review of the basic theoretical principles, experimental results and realistic simulation studies are given in the talk.

Bio
Romeo Ortega holds his BSc in electrical and mechanical engineering (1974) from the National University of Mexico, his MS in engineering (1978) from Polytechnical Institute of Leningrad and his Docteur D`Etat (1984) from the Polytechnical Institute of Grenoble, France. He then joined the National University of Mexico, where he worked until 1989. He is now in the Laboratoire des Signaux et Systemes of Supelec in Gif-sur-Yvette, France, where he holds the position of directeur de recherche from the CNRS. His research interests are in the fields of nonlinear and adaptive control with special emphasis on applications. He is a co-author of the Springer-Verlag book “Passivity-based control of Euler-Lagrange systems” and has published more than 100 scientific papers in international journals. He has been the chairman of the IEEE Working Group on Adaptive Control and Systems Identification, the IFAC Technical Committee on Adaptive Control and Tuning, and the Automatica Paper Prize Award Committee. He is a member of the IFAC Technical Board and a fellow of the IEEE.