Informatics Publishing Limited

G. S. Grewal

Abstract

Introduction of improved cross cut saws&bow saws can not only reduce the wastage in wood but these can save a lot of effort on the part of worker too. Hence the need for standardisation of saws. The criteria for a good saw should be performance based. It should take into account factors such as cutting efficiency, life of the saws and effort required to cut. The approach should be to demand a specific performance and not a particular teeth pattern etc.

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G. S. Grewal ¹, B. S. Rajpurohit ²

Affiliations
1 Ph D Scholar, School of Computing & Electrical Engineering, IIT Mandi, Mandi-175001, H.P., IN
2 Associate Professor, School of Computing & Electrical Engineering, IIT Mandi, Mandi - 175001, IN

Abstract

Various techniques have been suggested for efficiency estimation of Induction Machines (IMs) with different levels of intrusion and accuracy. Traditional methods depicted in IEEE Standard 112 can’t be employed for industrial environment where continuous industrial processes are in occurrence. This paper put forth an approach for non-intrusive air gap torque evaluation for efficiency estimation of IM by utilizing IM terminal quantities like input voltages and input currents. Base difference between Method-E and air-gap torque method is discussed. In vector control system, the speed estimation of IM is done based on Model-Reference Adaptive System (MRAS) by utilizing input electrical quantities and instantaneous reactive power. Algorithm used does not need intrusive no load testing. Experimental validation is carried out to verify the effectiveness of the proposed structure.

Keywords

Air-gap torque method, efficiency estimation, induction machine, non-intrusive techniques.

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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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