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Purna Chandra Rao A.,Prasad V Potluri Siddhartha Institute Of Technology | Obulesh Y.P.,Koneru Lakshmaiah College of Engineering | Sai Babu C.,Jawaharlal Nehru Technological University Kakinada
International Journal of Power Electronics and Drive Systems | Year: 2015

Earlier for variable speed application conventional motors were used, but these motors have poor characteristics. These drawbacks were overcome by brushless Dc motor drive. Now days in most of the applications such as industrial, domestic, aerospace, defense, medical and traction etc, brushless DC motor (BLDCM) is popular for its high efficiency, high torque to weight ratio, small size, and high reliability, ease of control and low maintenance etc. BLDC motor is a electronic commutator driven drive i.e. it uses a three-phase voltage source inverter for its operation, electronic devices means there is a problem of poor power quality, more torque ripple and speed fluctuations. This paper deals with the CUK converter two leg inverter fed BLDCM drive in closed loop operation. The proposed control strategy on CUK converter two leg inverter fed BLDCM drive with split DC source is modeled and implemented using MATLAB/Simulink. The proposed method improves the efficiency of the drive system with Power factor correction feature in wide range of the speed control, less torque ripple and smooth speed control. © 2015 Institute of Advanced Engineering and Science. All rights reserved. Source

Rao C.S.,Prasad V Potluri Siddhartha Institute Of Technology | Sudhakar A.,P.A. College
Applied Computational Electromagnetics Society Journal | Year: 2015

A finite length biconical antenna has standing waves existing due to its abrupt discontinuity at the terminals and results in band width limitation. An appropriate termination of these terminals can enhance its bandwidth to a considerable extent and make it truly wide band. A finite biconical antenna with its edges terminated in thick loop (circular) is proposed and its radiation characteristics are analyzed for different values of 'βr'. Where 'β' is the wave number and 'r' is the length of the antenna. Compact antennas for ultra wide band (UWB) and above are in demand for modern communications and the proposed antenna meets the wide band requirement at UWB and above such as X, Ku, K bands with very low return loss. © 2015 ACES. Source

Mounika M.,Prasad V Potluri Siddhartha Institute Of Technology
Materials Today: Proceedings | Year: 2015

Characterization, processing, manufacturing techniques, chemical treatment and applications of cellulose nanocomposites are the concerns of the work. With awareness to develop novel materials that are eco- friendly and biodegradable cellulose nanocomposites came into existence. This paper provides an general idea of recent advancements made in the field of cellulose based nanocomposites with particular emphasis on applications. Cellulose nanofibers extracted from bio waste are commercially interesting as they adopt renewability and furnish new products with a combination of properties. Many researchers tuned their path in a rather different direction which includes the production of all cellulose composites(ACC) in which the reinforcement as well the matrix is cellulose. This review summarizes why and what questions about cellulose composites. © 2015 Elsevier Ltd. Source

Srinivasababu N.,Prasad V Potluri Siddhartha Institute Of Technology | Rao M.M.,Sri Viveka Institute of Technology | Kumar J.S.,Jawaharlal Nehru Technological University Anantapur
Indian Journal of Fibre and Textile Research | Year: 2010

Turmeric fibre has been extracted from the stem and petiole of Tekurpeta and Cuddapha turmeric (Curcuma longa) and then used for the preparation of turmeric fibre reinforced polyester composites. For enhancing the bonding between fibre and matrix, one set of turmeric fibres is chemically treated with NaOH, KMnO4 and H2SO4 while another set is treated with only NaOH at varying chemical concentration and treatment time. The composites of Cuddapha turmeric stem fibre treated with 0.25 M NaOH for 13 h (CT-4 treatment) and Tekurpeta turmeric stem fibre treated with 0.125 M NaOH for 45 min, 0.01265 M KMnO4 for 5 min and 0.0000075 H2SO4 for 5 min (CT-1 treatment) show the highest tensile strength (36.01 MPa) for CT-4 and tensile modulus (744.32 MPa) for CT-1. The density of the composites shows decreasing trend with the increase in volume fraction of fibre in all the cases; density of Cuddapha turmeric composites being 956.77 kg/m3 the lowest among all the other composites studied at maximum volume fraction of fibre. Source

Subba Rao C.,Prasad V Potluri Siddhartha Institute Of Technology | Sudhakar A.,Rashtreeya Vidyalaya College of Engineering
ARPN Journal of Engineering and Applied Sciences | Year: 2011

Five element linear biconical array is proposed in this paper. The response of the array for standard non uniform amplitude excitations such as Binomial and Dolph-Tschebyscheff distributions are considered. Variation of radiation patterns in horizontal plane, vertical plane, Gain, beam width, side lobe levels and directivity are critically investigated. Behavior of Impedance, scattering parameters of the biconical dipole with frequency in array operation are elucidated. The response of the array and levels of various parameters for binomial and Dolph-Tschebyscheff amplitude excitations are critically compared and contrasted. Plots for various parameters are presented. Simple techniques for controlling side lobe levels and beam width of linear biconical dipole array are introduced. © 2006-2011 Asian Research Publishing Network (ARPN). Source

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