Delhi Technological University

About: Delhi Technological University is a education organization based out in New Delhi, India. It is known for research contribution in the topics: Computer science & Control theory. The organization has 4427 authors who have published 6761 publications receiving 71035 citations. The organization is also known as: Delhi College of Engineering & DTU.

AGC of a two‐area multi‐source power system interconnected via AC/DC parallel links under restructured power environment

Abstract: Summary In this paper, automatic generation control (AGC) of a two-area multi-source power system interconnected via alternating current/direct current (AC/DC) parallel links under restructured power environment is proposed Each area is equipped with multipower generating sources such as thermal and hydro/gas To execute the different market contracts in restructured power system, the optimal regulators are designed and implemented using optimal control theory It is observed that the system dynamic results effectively satisfy the AGC requirements in restructured power system, as well as the system dynamic performance is improved by using AC/DC parallel links in comparison with that obtained with AC link as an area interconnection between the control areas Furthermore, the eigenvalue study is performed to examine the system stability with and without AC/DC parallel links Finally, the effectiveness of the optimal regulators is checked for the system under study with physical constraints like time delay, boiler dynamics, generation rate constraints, and governor dead band nonlinearity and variations in system parameters from the nominal values It is shown that the optimal regulators optimized for linear system are robust enough and work well in the proposed realistic AGC system incorporating physical constraints and wide variations in parameters Copyright © 2015 John Wiley & Sons, Ltd

Modified f ( R , T ) gravity theory and scalar field cosmology

Abstract: In this paper, we explore the behaviors of scalar field in modified f(R,T) gravity theory within the framework of a flat Friedmann-Robertson-Walker cosmological model. The universe is assumed to be filled with two non-interacting matter sources, scalar field (normal or phantom) with scalar potential and matter contribution due to f(R,T) action. We first explore a model where the potential is a constant, and the universe evolves as a de Sitter type. This model is compatible with phantom scalar field only which gives fine tuning with the recent observations. The model exhibits a wide variety of early time physical phenomena that eventually behaves like a cosmological constant at late times. The model shows transition from decelerated to accelerated expansion of the universe. We also explore a model where the scalar field potential and the scale factor evolve exponentially as a scalar field. This model is compatible with normal scalar field only and describes transition from inflationary to the decelerated phase at early times and quintessence to phantom phase at late times. We constraint our results with the recent observational data and find that some values of parameters are consistent with SNe Ia and H(z)+SNe Ia data to describe accelerated expansion only whereas some one give decelerated and accelerated expansions with H(z), WMAP7 and WMAP7+BAO+H(z) observational data.