11,192 research outputs found
Nonlinear Analysis and Control of Interleaved Boost Converter Using Real-Time Cycle to Cycle Variable Slope Compensation
Switched-mode power converters are inherently nonlinear and piecewise smooth systems that may exhibit a series of undesirable operations that can greatly reduce the converter's efficiency and lifetime. This paper presents a nonlinear analysis technique to investigate the influence of system parameters on the stability of interleaved boost converters. In this approach, Monodromy matrix that contains all the comprehensive information of converter parameters and control loop can be employed to fully reveal and understand the inherent nonlinear dynamics of interleaved boost converters, including the interaction effect of switching operation. Thereby not only the boundary conditions but also the relationship between stability margin and the parameters given can be intuitively studied by the eigenvalues of this matrix. Furthermore, by employing the knowledge gained from this analysis, a real-Time cycle to cycle variable slope compensation method is proposed to guarantee a satisfactory performance of the converter with an extended range of stable operation. Outcomes show that systems can regain stability by applying the proposed method within a few time periods of switching cycles. The numerical and analytical results validate the theoretical analysis, and experimental results verify the effectiveness of the proposed approach
Delay time modulation induced oscillating synchronization and intermittent anticipatory/lag and complete synchronizations in time-delay nonlinear dynamical systems
Existence of a new type of oscillating synchronization that oscillates
between three different types of synchronizations (anticipatory, complete and
lag synchronizations) is identified in unidirectionally coupled nonlinear
time-delay systems having two different time-delays, that is feedback delay
with a periodic delay time modulation and a constant coupling delay.
Intermittent anticipatory, intermittent lag and complete synchronizations are
shown to exist in the same system with identical delay time modulations in both
the delays. The transition from anticipatory to complete synchronization and
from complete to lag synchronization as a function of coupling delay with
suitable stability condition is discussed. The intermittent anticipatory and
lag synchronizations are characterized by the minimum of similarity functions
and the intermittent behavior is characterized by a universal asymptotic
power law distribution. It is also shown that the delay time carved
out of the trajectories of the time-delay system with periodic delay time
modulation cannot be estimated using conventional methods, thereby reducing the
possibility of decoding the message by phase space reconstruction.Comment: accepted for publication in CHAOS, revised in response to referees
comment
Fundamentals and applications of spatial dissipative solitons in photonic devices : [Chapter 6]
We review the properties of optical spatial dissipative solitons (SDS). These are stable, self‐localized optical excitations sitting on a uniform, or quasi‐uniform, background in a dissipative environment like a nonlinear optical cavity. Indeed, in optics they are often termed “cavity solitons.” We discuss their dynamics and interactions in both ideal and imperfect systems, making comparison with experiments. SDS in lasers offer important advantages for applications. We review candidate schemes and the tremendous recent progress in semiconductor‐based cavity soliton lasers. We examine SDS in periodic structures, and we show how SDS can be quantitatively related to the locking of fronts. We conclude with an assessment of potential applications of SDS in photonics, arguing that best use of their particular features is made by exploiting their mobility, for example in all‐optical delay lines
Feedback Control of Traveling Wave Solutions of the Complex Ginzburg Landau Equation
Through a linear stability analysis, we investigate the effectiveness of a
noninvasive feedback control scheme aimed at stabilizing traveling wave
solutions of the one-dimensional complex Ginzburg Landau equation (CGLE) in the
Benjamin-Feir unstable regime. The feedback control is a generalization of the
time-delay method of Pyragas, which was proposed by Lu, Yu and Harrison in the
setting of nonlinear optics. It involves both spatial shifts, by the wavelength
of the targeted traveling wave, and a time delay that coincides with the
temporal period of the traveling wave. We derive a single necessary and
sufficient stability criterion which determines whether a traveling wave is
stable to all perturbation wavenumbers. This criterion has the benefit that it
determines an optimal value for the time-delay feedback parameter. For various
coefficients in the CGLE we use this algebraic stability criterion to
numerically determine stable regions in the (K,rho) parameter plane, where rho
is the feedback parameter associated with the spatial translation and K is the
wavenumber of the traveling wave. We find that the combination of the two
feedbacks greatly enlarges the parameter regime where stabilization is
possible, and that the stability regions take the form of stability tongues in
the (K,rho)--plane. We discuss possible resonance mechanisms that could account
for the spacing with K of the stability tongues.Comment: 33 pages, 12 figure
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