Power electronics circuits are rich in nonlinear dynamics. Their operation is characterized by cyclic switching of circuit topologies, which gives rise to a variety of nonlinear behavior. This paper provides an overview of the chaotic dynamics and bifurcation scenarios observed in power converter circuits, emphasizing the salient features of the circuit operation and the modeling strategies. In particular, this paper surveys the key publications in this field, reviews the main modeling approaches, and discusses the salient bifurcation behaviors of power converters with particular emphasis on the disruption of standard bifurcation patterns by border collisions.

This review paper starts by setting out the aims and applications of power electronics, and continues with a brief history and a list of the important power semiconductor devices. The related areas of ac machines and power systems are also briefly visited. The development of nonlinear dynamics in electronic circuits is reviewed. Then a typical power converter, a controlled buck dc-dc converter, is modelled by the conventional method of averaging and linearisation (which predicts stability), and by a nonlinear map based method, which reveals bifurcations, subharmonics and chaos. The numerical problems caused by the discontinuities in the state equations of power electronics are discussed. Finally, some possible future applications are considered. 1 Introduction to Power Electronics M ost branches of electronics are concerned with processing information or signals; in contrast, power electronics deals with the processing of electrical energy. Power converters do not have an end of

LUNSFORD II, PHILIP J. The Frequency Domain Behavioral Modeling and Simulation of Nonlinear Analog Circuits and Systems. (Under the direction of Michael B. Steer.) A new technique for the frequency-domain behavioral modeling and simulation of nonautonomous nonlinear analog subsystems is presented. This technique extracts values of the Volterra nonlinear transfer functions and stores these values in binary files. Using these files, the modeled substem can be simulated for an arbitrary periodic input expressed as a finite sum of sines and cosines. Furthermore, the extraction can be based on any circuit simulator that is capable of steady state simulation. Thus a large system can be divided into smaller subsystems, each of which is characterized by circuit level simulations or lab measurements. The total system can then be simulated using the subsystem characterization stored as tables in binary files.