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Full-Text Articles in Engineering

Variable Structure Control Of Unsteady Nonlinear Aeroelastic System, With Partial State Information, Sushma Gujjula, Sahjendra N. Singh Aug 2005

Variable Structure Control Of Unsteady Nonlinear Aeroelastic System, With Partial State Information, Sushma Gujjula, Sahjendra N. Singh

Electrical & Computer Engineering Faculty Research

This paper treats the question of control of a two-degree-of-freedom unsteady aeroelastic system with partial state information in the presence of uncertainties. The chosen model describes the plunge and pitch motion of a wing and a single trailing-edge control surface is utilized for the purpose of control. Based on the Lyapunov approach, a variable structure control law is derived. For the control law derivation, the system is treated as the interconnection of two subsystems in which the subsystem associated with the unsteady aerodynamics is input-to-state stable. The stability property of this subsystem is exploited to generate a dominating signal for …


A Three-Dimensional Fdtd Subgridding Method With Separate Spatial And Temporal Subgridding Interfaces, Kai Xiao, David Pommerenke, James L. Drewniak Aug 2005

A Three-Dimensional Fdtd Subgridding Method With Separate Spatial And Temporal Subgridding Interfaces, Kai Xiao, David Pommerenke, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

The idea of separating the spatial and temporal subgridding interfaces is introduced in this paper. Based on this idea, the spatial and temporal subgridding algorithms can be developed and analyzed separately. The spatial algorithm was given in the previous paper. In this paper, the temporal subgridding algorithm is described and the stability is illustrated by the analytical formulation of a one-dimensional model. An FDTD code that combines the spatial and temporal subgridding algorithms is implemented. Numerical test models are calculated to show the stability and accuracy of the proposed method.


Coordination Of Ufls And Ufgc By Application Of D-Smes, Li Zhang, Yilu Liu, Mariesa Crow Jun 2005

Coordination Of Ufls And Ufgc By Application Of D-Smes, Li Zhang, Yilu Liu, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, the authors studied the coordination of under frequency load shedding (UFLS) and under frequency governor control (UFGC) by applying the distributed superconducting magnetic energy storage (D-SMES) devices. The active power of D-SMES device is controlled to eliminate the initial rapid frequency drop and allow time for the full action of UFGC to take over. The reactive power of D-SMES is controlled to stabilise the local bus voltage. The research results show that D-SMES devices can damp the quick dropping of system frequency and hold it waiting for the full activation of system spinning reserve. D-SMES can help …


Pulse Regulation Control Technique For Integrated High-Quality Rectifier-Regulators, Mehdi Ferdowsi, Ali Emadi Feb 2005

Pulse Regulation Control Technique For Integrated High-Quality Rectifier-Regulators, Mehdi Ferdowsi, Ali Emadi

Electrical and Computer Engineering Faculty Research & Creative Works

The pulse regulation control scheme is presented and applied to the boost integrated flyback rectifier/energy storage dc/dc (BIFRED) converter as the most popular member of the integrated high-quality rectifier-regulators (IHQRR). In contrast to the conventional control techniques, the principal idea of pulse regulation is to regulate the output voltage using a series of high- and low-power pulses generated by the current of the input inductor, which is operating in discontinuous conduction mode (DCM). Analysis of the BIFRED converter operating in DCM is presented. Fundamentals of pulse regulation as well as its stability analysis and the estimation of the output voltage …