Chung-Chieh Fang

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heterogeneous and dynamic problems of engineering technology and systems for industry and government. ISR is a permanent institute of the University of Maryland, within the Glenn L. Martin Institute of Technology/A. James Clark School of Engineering. It is a National Science Foundation Engineering Research Center. Web site I R(More)
Period doubling bifurcation in buck converters is studied by using the harmonic balance method. A simple dynamic model of a buck converter in continuous conduction mode under voltage mode or current mode control is derived. This model consists of the feedback connection of a linear system and a nonlinear one. An exact harmonic balance analysis is used to(More)
Design-oriented boundary conditions for subharmonic oscillations are of great interest recently. Based on a subharmonic oscillation boundary condition reported in a PhD thesis more than a decade ago, extended new boundary conditions are derived in closed forms for general switching DC-DC converters. Sampled-data and harmonic balance analyses are applied and(More)
General block diagram models are proposed for PWM DC-DC converters in continuous and discontinuous conduction modes with fixed switching frequency. Both current mode control and voltage mode control are addressed in these models. Based on these models, detailed nonlinear and linearized sampled-data dynamics are derived. Asymptotic orbital stability is(More)
Abstract Dynamics and stability of average current control of DC-DC converters are analyzed by sampleddata modeling. Orbital stability is studied and it is found unrelated to the ripple size of the orbit. Compared with the averaged modeling, the sampled-data modeling is more accurate and systematic. An unstable range of compensator pole is found by(More)