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IJSTR >> Volume 6 - Issue 4, April 2017 Edition

International Journal of Scientific & Technology Research  
International Journal of Scientific & Technology Research

Website: http://www.ijstr.org

ISSN 2277-8616

Real And Reactive Power Saving In Three Phase Induction Machine Using Star-Delta Switching Schemes

[Full Text]



Ramesh Daravath, Lakshmaiah Katha, Ch. Manoj Kumar, AVS Aditya



Real and Reactive power saving, light loading, case study of induction machine, phase controlled anti parallel thyristor bank, star-delta switching, harmonics, predetermined values



Induction machines are the most commonly used industrial drives for variety of applications. It has been estimated that induction motors consumes approximately 50 % of all the electric energy generated. Further, in the area of renewable energy sources, such as wind or bio-mass energy, induction machines have been found suitable for functioning as generators. In this context, it may be mentioned that a star-delta switching is common for the starting of three-phase induction motor. Now, it is proposed to use this star-delta switching for energy conservation of induction machines, i.e., at times of reduced loads, the machine switched back to star connection. Using a three-phase, 400 V, 50 Hz, 4-pole induction machine, it has been demonstrated that the star-delta switching of stator winding of three-phase induction machine (motor / generator operations) reconnected in star at suitable reduced loads with a switching arrangement, can result in improved efficiency and power factor, as compared to a fixed delta or star connection. The predetermined values along with the experimental results have also been presented in this report. A simulation program has been developed for the predetermination of performance of the three-phase induction machine using exact equivalent circuit. A case study on a 250 kW, 400 V, 4-pole, three-phase induction machine, operated with different load cycles, reveals the significant real and reactive power savings that could be obtained in the present proposal.



[1] N. Mohan, “Improvement in energy efficiency of induction motors by means of voltage control”, IEEE transaction on Power apparatus and systems, Vol. PAS-99, No. 4, July/ August 1980, pp.1466-1471.

[2] A. Abdel-halim, A.F. Almarshoud, and A.I. Alolah, “Performance of grid-connected induction generator under naturally commutated ac voltage controller”, Electric Power Components and Systems, Vol.32, No.7, July 2004, pp.691-700.

[3] Hideo Tomita and Toshimasa Haneyoshi, “An optimal efficiency control for energy saving of ac motor by thyristor voltage controller”, IEEE international conference IECON 1988, pp.816-819.

[4] N. Kumaresan , N.Ammasai Gounden, M.Subbiah, T.R. Selvakumar, “A Thyristor controller for energy conservation in three-phase Induction motors”, Fifth international conference on electrical rotating machines, ELROMA-99, 25th and 26th January 1999, Mumbai, pp.1-8.

[5] S.A. Hamed, B.J. Chalmers, “Analysis of variable voltage thyristor controlled induction motors”, IEE proceedings, Vol.137, Pt.B.No.3, May 1990, pp. 184-193.

[6] M.G. SAY, “Alternating current machines”, The English Language Book Society and Pitman publishing, Edinburgh, UK, 1976.

[7] N. Kumaresan and M. Subbiah, “Innovative reactive power saving in wind-driven grid-connected induction generators using a delta-star stator winding: part I, Performance analysis of the delta-star generator and test results”, Wind Engineering, Vol.27, No.2, 2003, pp.107 – 120.

[8] N. Kumaresan and M. Subbiah, “Innovative reactive power saving in wind-driven grid-connected induction generators using a delta-star stator winding: part II, Estimation of annual Wh and VARh of the delta-star generator and comparison with alternative schemes”, Wind Engineering, Vol.27, No.3, 2003, pp.195-204.

[9] S. Sudha, N. Ammasaigounden and M. Subbiah “A thyristor controller for power factor improvement of wind-farm induction generators”, pp. session V-19-26, Proceedings of the Fourth International Seminar on Power Electronics & Automation ELECRAMA-99, IEEMA, Mumbai, India, 1999.

[10] M.A. Abdel-Halim, “Solid-state control of a grid connected induction generator”, Electric Power Components and systems, Vol.29, 2001, pp. 163-178