Vignans Engineering College

andhra Pradesh, India

Vignans Engineering College

andhra Pradesh, India
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Subbarao M.,Vignans Engineering College | Satyanarayana S.,VRS and YRN Engineering College | Sobhan P.V.S.,Vignans Engineering College
Advances in Electrical and Electronic Engineering | Year: 2011

Paralleling of converter modules is a wellknown technique that is often used in medium-power applications to achieve the desired output power by using smaller size of high frequency transformers and inductors. In this paper, a parallel-connected singlephase PFC topology using flyback and forward converters is proposed to improve the output voltage regulation with simultaneous input power factor correction (PFC) and control. The goal of the control is to stabilize the output voltage of the converter against the load variations. The paper presents the derivation of fuzzy control rules for the dc/dc converter circuit and control algorithm for regulating the dc/dc converter. This paper presents a design example and circuit analysis for 200 W power supply. The proposed approach offers cost effective, compact and efficient AC/DC converter by the use of parallel power processing. MATLAB/SIMULINK is used for implementation and simulation results show the performance improvement. © 2011 ADVANCES IN ELECTRICAL AND ELECTRONIC ENGINEERING.

Venkata Narasimha Rao G.,Mylan Laboratories Ltd | Gnanadev G.,Mylan Laboratories Ltd | Ravi B.,Mylan Laboratories Ltd | Dhananjaya D.,Mylan Laboratories Ltd | And 3 more authors.
Analytical Methods | Year: 2013

UltraPerformance convergence chromatography (UPC2™) is a new category of separation science which utilizes the unrealized potential of the supercritical chromatography phenomenon. UPC2™ is a stand-alone, viable technique that is cost effective, sustainable, and uses green technology that lowers the use of organic solvents. Based on this advantage, we explored a simple and robust supercritical liquid-based UPC 2 method in order to increase sample throughput and productivity to quantify the diastereomers of fulvestrant. The two isomers of fulvestrant were well separated on a chiral column (150 mm × 4.6 mm, I.D.) by applying a mixture of methanol and acetonitrile (9.5:0.5) as the co-solvent of the mobile phase of carbon dioxide (75%). The detection was carried out at 280 nm. We were able to achieve a three-fold reduction in retention with an isocratic mode as compared to the United States Pharmacopoeias (USP) normal phase method. This new method was validated in accordance with the ICH guidelines; it exhibited good intra- and inter-day accuracy, precision, and the results were linear over a range of 25% to 150% of the target concentration. The method could be successfully applied for the determination of the diastereomeric ratio of fulvestrant as an API and in fulvestrant injectable finished products. © 2013 The Royal Society of Chemistry.

Malla J.M.R.,Gandhi Institute of Engineering and Technology | Malla S.G.,Vignans Engineering College
WSEAS Transactions on Power Systems | Year: 2010

Direct Torque Control is a control technique used in AC drive systems to obtain high performance torque control. The conventional DTC drive contains a pair of hysteresis comparators, a flux and torque estimator and a voltage vector selection table. The torque and flux are controlled simultaneously by applying suitable voltage vectors, and by limiting these quantities within their hysteresis bands, de-coupled control of torque and flux can be achieved. However, as with other hysteresis-bases systems, DTC drives utilizing hysteresis comparators suffer from high torque ripple and variable switching frequency. The most common solution to this problem is to use the space vector with multilevel inverter depends on the reference torque and flux. The reference voltage vector is then realized using a voltage vector modulator. Several variations of DTCSVM with low cost multilevel inverter or parallel inverter (five level) have been proposed and discussed in the literature. The work of this project is to study, evaluate and compare the various techniques of the DTC-SVM with parallel inverter applied to the induction machines through simulations. The simulations were carried out using MATLAB/SIMULINK simulation package. Evaluation was made based on the drive performance, which includes dynamic torque and flux responses, feasibility and the complexity of the systems. It is better technology in electric vehicles.

Srinivasa Rao G.,Vignans Engineering College | Kesava Rao G.,Vignans Engineering College | Sivanagaraju S.,Vignans Engineering College | Murthy G.R.K.,Vignans Engineering College | Sudheer B.C.N.S.,Vignans Engineering College
International Journal of Electric and Hybrid Vehicles | Year: 2011

This paper proposes an automated battery management system (ABMS) for electric vehicles (EV) and hybrid electric vehicles (HEV) to increase the lifecycle of the batteries. Automated battery management system is needed to enhance the life of the battery set by individually recharging the batteries and monitoring them while being charged. This will enable the battery management system to recharge the batteries fully and to determine if any of the batteries is not accepting charge. Based on the state of charge (SOC) of the set, a specific number of batteries is automatically selected for propulsion by using computer and associated interfacing circuits. To realise this logic, a programme has been developed in C language which automatically rejuvenates batteries, charges and discharges individual batteries in pack, and protects each battery from over discharge and over charge. Copyright © 2011 Inderscience Enterprises Ltd.

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