9,988 research outputs found
Stabilization of structure-preserving power networks with market dynamics
This paper studies the problem of maximizing the social welfare while
stabilizing both the physical power network as well as the market dynamics. For
the physical power grid a third-order structure-preserving model is considered
involving both frequency and voltage dynamics. By applying the primal-dual
gradient method to the social welfare problem, a distributed dynamic pricing
algorithm in port-Hamiltonian form is obtained. After interconnection with the
physical system a closed-loop port-Hamiltonian system of differential-algebraic
equations is obtained, whose properties are exploited to prove local asymptotic
stability of the optimal points.Comment: IFAC World Congress 2017, accepted, 6 page
Digital waveguide modeling for wind instruments: building a state-space representation based on the Webster-Lokshin model
This paper deals with digital waveguide modeling of wind instruments. It presents the application of state-space representations for the refined acoustic model of Webster-Lokshin. This acoustic model describes the propagation of longitudinal waves in axisymmetric acoustic pipes with a varying cross-section, visco-thermal losses at the walls, and without assuming planar or spherical waves. Moreover, three types of discontinuities of the shape can be taken into account (radius, slope and curvature).
The purpose of this work is to build low-cost digital simulations in the time domain based on the Webster-Lokshin model. First, decomposing a resonator into independent elementary parts and isolating delay operators lead to a Kelly-Lochbaum network of input/output systems and delays. Second, for a systematic assembling of elements, their state-space representations are derived in discrete time. Then, standard tools of automatic control are used to reduce the complexity of digital simulations in the time domain. The method is applied to a real trombone, and results of simulations are presented and compared with measurements. This method seems to be a promising approach in term of modularity, complexity of calculation and accuracy, for any acoustic resonators based on tubes
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