Informatics Publishing Limited

P. Swathi Priya ¹, O. Chandra Sekhar ¹, M. Ramamoorty ¹

Affiliations
1 Department of Electrical Engineering, K L University, Green Fields, Vaddeswaram, Guntur - 522502, Andhra Pradesh, IN

Abstract

In this paper, theoretical and practical design of low speed single side linear induction motor of secondary as reaction rail is proposed. At no load condition, a DC voltage is injected to the stator winding to one of the phase to analyse the static magnetic field across the mean length and also to the other phases dc voltage is injected and analysed that the magnetic flux shift spatially that makes the flux travels from one end of the primary to the other end. For increasing input dc current the magnetic flux density also increases by its square. By applying ac voltage, the output speed, thrust characteristics are measured. The static magnetic field and output characteristics of linear induction motor had analysed through experimental calculations.

Keywords

Linear Induction Motor (LIM), Static Magnetic Field, Travelling Flux.

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J. N. S. Mrudveeka ¹, S. V. N. L. Lalitha ¹, M. Ramamoorty ¹

Affiliations
1 EEE, K L University, Vaddeswaram, Guntur district - 520002, Andhra Pradesh, IN

Abstract

Objective: Load modelling has a prominent place in present scenario of power systems research. In this paper various load models are considered for assessing maximum loadability using new algorithms. This has got a lot of significance in the voltage stability studies. Methods/Analysis: Generally constant representation of loads was considered. But the load characteristics significantly affect the power system’s performance. Constant models can not accurately describe the actual nature and behaviour of loads. Findings: Constant Power, Constant Impedance, Constant Current as well as composite (ZIP) load model are considered for assessing maximum loadability using a new algorithm. Constant Impedance, Constant Current Load models are established using node elimination technique. Application/Improvements: Case studies are conducted on IEEE 14 bus system with different load models and the test results are compared.

Keywords

Constant Current Model (I), Constant Impedance Model (Z), Constant Power Model (P), Maximum Loadability, ZIP Model

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B. Mounika ¹, S. V. N. L. Lalitha ¹, M. Ramamoorty ¹

Affiliations
1 EEE, K L University, Vaddeswaram, Guntur District – 520002, Andhra Pradesh, IN

Abstract

Objective: State estimation is used as a necessary tool for online monitoring, analysis and control of power systems. The main objective of this paper is to deal with static state estimation using the snap shot data and dynamic state estimation which accounts for the time varying behaviour of power system states in to consideration. Methods/Analysis: Effects of inclusion of PMU measurements along with the available metered data have been explored using the weighted least square state estimation technique in this paper. A comparative analysis of static state estimation with and without bad data has been carried out and the bad data has been identified and eliminated by using largest normalized residue test. Findings: To investigate the time varying nature of the system states linear state estimator with second order approximation and kalman filter techniques has been proposed in this paper. Case studies are conducted on IEEE 14 bus test system and the test results obtained from non linear, linear first order, second order and kalman filter techniques have been compared. Application/Improvements: Correction of state variables are obtained using linear state estimation with first order and second order approximation and kalman filter techniques has been compared to get the better state estimation algorithm.

Keywords

Bad Data, Kalman Filter, PMU, State Estimation, Static, Dynamic, Weighted Least Squares.

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S. S. Godkhindi ¹, G. S. Grewal ¹, P. B. Joshi ², M. Ramamoorty ³, N. J. Buch ¹

Affiliations
1 Electrical Research and Development Association, ERDA Road, Makarpura, Vadodara - 390 010, IN
2 Professor, Metallurgical and Materials Engineering Department, Faculty of Technology and Engineering, M.S. University of Baroda, Vadodara - 390 001, IN
3 Former Director, ERDA, IN

Abstract

The use of cadmium and cadmium oxide containing contact materials has been strongly discouraged in most parts of the world in view of the toxicity of these materials and resultant environmental and health hazards. Tin oxide has emerged as a substitute material in place of cadmium oxide as the major modern silver-metal oxide contact system for industrial application. The traditional methods of synthesis of silver-cadmium oxide composite contacts (namely internal oxidation and powder metallurgy route of co-precipitation) have been found to be unsuitable for production of silver-tin oxide contact material mainly because of incompatibility of existing compounds of tin metal that are water soluble and which can be used for co-precipitation with silver salt such as silver nitrate as well as the very slow rates of internal oxidation of tin in silver-tin oxide system as compared to that of cadmium in silver-cadmium oxide system. For synthesis of silver-tin oxide powders, a novel method based on electroless coating, has been developed. In the present work, an optimization study has been undertaken for improving the arc erosion characteristics of silver tin oxide contacts, prepared using the novel electroless route with additions of a tertiary stabilizing tungsten oxide dopant. The work has been undertaken in a Statistical Factorial Design of Experiment (SDOE) setting using the one way ANOVA technique.

Keywords

Silver Cadmium Oxide, Silver Tin Oxide, Electroless and Arc Erosion Resistance.

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