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.
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.
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).
Rao A.P.C.,Prasad V Potluri Siddhartha Institute Of Technology |
Babu C.S.,Jawaharlal Nehru Technological University Kakinada
7th International Conference on Intelligent Systems and Control, ISCO 2013 | Year: 2013
Multilevel converter technology has emerged as a very important alternative in the area of high-power medium-voltage energy control. Several topologies for multilevel inverters have been proposed over the years, the most popular cascaded H-bridge apart from other multilevel inverters is the capability of utilizing different dc voltages on the individual H-bridge cells which results in splitting the power conversion amongst higher-voltage lower-frequency and lower-voltage higher-frequency inverters. Considering the cascaded inverter to be one unit, it can be seen that a higher number of voltage levels are available for a given number of semiconductor devices. In this paper multilevel converter with different voltage levels are considered and simulation results are presented in terms of total harmonic distortion (THD). Finally generalized expression for highest order harmonic based on switching frequency and number of levels is derived and fed to BLDC drive. © 2013 IEEE.
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.
Shahanaz Mubeena S.K.,Prasad V Potluri Siddhartha Institute Of Technology |
Rao C.S.,Prasad V Potluri Siddhartha Institute Of Technology |
Eswara Reddy C.,Sri Venkateswara University
International Journal of Applied Engineering Research | Year: 2011
Scanning Electron Microscope (SEM) is one of the advent in the field of nano surface characterization tools. It is mainly aimed for morphological analysis but can also be used for elemental analysis in conjunction with Energy Dispersive Spectroscopy (EDS). Even though some experimental investigation has been carried using SEM for morphological studies, but still there is some work to be carried for morphological as well as elemental investigation in combination with EDS on coated samples like High Speed Steel (HSS) with Nickel. An HSS sample of 2cm X 1cm X 1mm is chosen and coated with Nickel in the order of 300 μm. With the variation of magnification factor, the distribution of nano particles with in the samples of the constituents has been estimated at a constant acceleration voltage of 15KV. The elemental composition and surface structure plays a major role in the mechanical behavior of the materials. Therefore, the present paper has been focused on experimental investigation on morphological and elemental analysis of Nickel coated HSS at various accelerating currents. The elements analyzed during morphological studies are Carbon, oxygen and Nickel etc. The studies of coated samples have been carried using SEM by the secondary electron imaging (SEI) or backscattered electron imaging (BEI) mode and elemental analysis by Energy Dispersive Spectroscopy (EDS). © Research India Publications.
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.
Ravisankar P.,P.A. College |
Devadasu CH.,P.A. College |
Devala Rao G.,P.A. College |
Nageswara Rao M.,Prasad V Potluri Siddhartha Institute Of Technology
Asian Journal of Pharmaceutical and Clinical Research | Year: 2014
Objective: To develop a simple, accurate, precise and selective isocratic reversed phase-high performance liquid chromatography (RP-HPLC) method was developed for the quantitative estimation of Sparfloxacin in pharmaceutical formulations. Experimental: RP-HPLC method was developed by using Welchrom C18 Column with 250 mm x 4.6 mm i.d and 5μm particle size, SHIMADZU LC-20AT Prominence liquid chromatograph. The mobile phase used is phosphate buffer (pH-3.0): acetonitrile (70:30% v/v) with a flow rate of 1mL/min. The eluent was monitored by UV detection at 291nm using SHIMADZU SPD-20A prominence UV-Vis detector. Results: The retention time of Sparfloxacin found to be 5.499 min. The method retains linearity in the range of 2-10μg/mL with correlation coefficient 0.9999. The mean recovery of sparfloxacin was 99.702% to 100.456%. The LOD and LOQ of the drug were found to be 0.186 μg/mL and 0.558 μg/mL respectively. Conclusion: The proposed method can be successfully used for routine determination of sparfloxacin in pharmaceutical formulations.
Raju C.P.,Prasad V Potluri Siddhartha Institute Of Technology |
Kumar C.,Prasad V Potluri Siddhartha Institute Of Technology |
Lavanya K.S.L.,Prasad V Potluri Siddhartha Institute Of Technology
International Conference on Electrical, Electronics, Signals, Communication and Optimization, EESCO 2015 | Year: 2015
This paper presents an Interior point method (IPM) and Adaptive particle swarm optimization (APSO) based hybrid method to solve the contingency constrained optimal power flow (OPF) in power systems incorporated with Flexible AC Transmission Systems (FACTS). Versatile FACTS devices TCPS (Thyristor controlled phase shifter) and Static Synchronous Series Compensator (SSSC) are considered. In the solution process APSO coupled with IPM to keep the power flows within their security limits. This Hybrid OPF algorithm with FACTS effectively relieves line flow violations under different single line contingencies. Severity Index is used as an objective function to be minimized to improve the security of the power system. The efficiency of proposed algorithm is illustrated by carrying simulation studies on IEEE 30 bus system. This analysis reveals that the proposed algorithm is quite simple and efficient for solving OPF problem. © 2015 IEEE.
Phanindra G.,Prasad V Potluri Siddhartha Institute Of Technology |
Raju C.P.,Prasad V Potluri Siddhartha Institute Of Technology
International Conference on Electrical, Electronics, Signals, Communication and Optimization, EESCO 2015 | Year: 2015
This paper acquaints power flow control and power flow studies for a power system with flexible ac transmission system (FACTS) devices. The power system power flow control deals with the task of taking remedial measures against overloads and non linear loads in the system due to the occurrence of contingencies. For power flow studies, the modelings of FACTS devices are discussed. Several power flow programs are created to model the FACTS devices. The paper presents a reliable method to solve the nonlinear load flow equations by developing a Newton-Raphson method with UPFC. The particle swarm optimization technique (PSO) is on of the evolutionary optimization method which is used to reschedule the generation. Power flow study programming was accomplished by using MATLAB. PSO method is implemented along with UPFC device to reschedule the generators to maximize net savings. Convergence test studies have been performed on standard IEEE 30-bus network to show that the proposed method is effective and robust under various conditions like with and without UPFC FACTS devices. © 2015 IEEE.