Time filter

Source Type

Zanjan, Iran

The University of Zanjan is located in Zanjan, Iran. It was founded in 1975 and organized in 4 Faculties. It is also counted by Iran's census as a settlement in Zanjanrud-e Bala Rural District, in the Central District of Zanjan County, Zanjan Province, Iran. At the 2006 census, its population was 125, in 36 families. Wikipedia.

This paper addresses a novel global nonlinear sliding surface to achieve robustness and high performance for a class of uncertain nonlinear systems. Using the Lyapunov stability theorem, exponential stability analysis of the system states is proposed in the linear matrix inequality form. A new control law is designed to guarantee the elimination of the reaching phase and the existence of the sliding mode around the nonlinear surface right from the beginning. Two illustrative simulations are presented to demonstrate the robustness and effectiveness of the introduced design. It is worthwhile noticing that the proposed approach can be applied to a wide variety of uncertain nonlinear control problems. © 2014, Springer Science+Business Media Dordrecht.

This paper presents an approach of achieving high performance and robustness for matched uncertain multi-input multi-output linear systems with external disturbances and multiple state-delays, which are often encountered in practice and are frequently the sources of instability. This scheme is based on composite nonlinear feedback and integral sliding mode control methods. The selection of nonlinear function and the existence of sliding mode are two important issues, which have been addressed. The control law is designed to guarantee the existence of the sliding mode around the nonlinear surface, and the damping ratio of the closed-loop system is increased as the output approaches the set-point. Simulation results are presented to show the effectiveness of the proposed method as a promising way for controlling similar nonlinear systems. © 2014 Springer Science+Business Media Dordrecht.

This paper presents a new recursive terminal sliding mode strategy for tracking control of disturbed chained-form nonholonomic systems whose reference targets are allowed to converge to zero in finite time with an exponential rate. By introducing time-varying coordinate transformation and designing a novel control law, the existence of the sliding mode around the terminal sliding surface is guaranteed. Simulation results are applied on two benchmark examples of chained-form nonholonomic systems: a wheeled mobile robot and an underactuated rigid body. The simulation results show the efficiency of the proposed method in the presence of external disturbances. © 2015, Springer Science+Business Media Dordrecht.

Ghazanfarian J.,University of Zanjan | Shomali Z.,Institute for Advanced Studies in Basic Sciences
International Journal of Heat and Mass Transfer | Year: 2012

This paper investigates the numerical simulation of non-Fourier transient heat transfer in a two-dimensional sub-100 nm metal-oxide-semiconductor field-effect transistor (MOSFET). The dual-phase-lag (DPL) model with a specific normalization procedure is introduced for the modeling of nanoscale heat transport. The boundary conditions are selected similar to what existed in a real MOSFET device, both uniform and non-uniform heat generations within the transistor are applied, and the end parts of the top boundary which are in contact with the metallic material are left open. A temperature-jump boundary condition is used on all boundaries in order to consider the boundary phonon scattering at micro and nanoscale. A three-level finite difference scheme has been employed to generate the numerical results which are illustrated for a silicon sub-100 nm MOSFET corresponding to the Knudsen number of 10. The results are presented at real times less than 50 ps to avoid the three-dimensional effects. It is concluded that the combination of the DPL model with mixed-type temperature boundary condition is able to predict the heat flux and temperature distribution obtained from the Boltzmann transport equation (BTE) more accurate than the ballistic-diffusive equations (BDE). After verification of our results, the thermal field and the hotspot temperature within the bulk silicon are presented and the effect of adding a layer of silicon-dioxide to the transistor on its thermal behavior has been investigated. © 2012 Elsevier Ltd. All rights reserved.

Noroozian R.,University of Zanjan | Gharehpetian G.B.,Amirkabir University of Technology
International Journal of Electrical Power and Energy Systems | Year: 2013

In this paper, the combined operation of the active power filter with the photovoltaic generation system has been studied. The proposed system consists of a PV power plant, a DC-DC boost converter, and an active power filter. A novel control strategy for the DC-DC converter has been developed in order to extract the maximum amount of power from PV arrays. Also, a novel control strategy, which is based on generalized instantaneous reactive power theory, has been proposed for the active power filter. The simulation results, based on PSCAD/EMTDC, show that the proposed system can provide the power factor correction, load balancing, harmonic elimination, reactive power compensation and simultaneously inject the maximum power available from the PV array into the grid. © 2012 Elsevier Ltd. All rights reserved.

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