Journal of Applied Science and Engineering

Published by Tamkang University Press


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Nageswara Rao Pulivarthi This email address is being protected from spambots. You need JavaScript enabled to view it.1, G. V. Siva Krishna Rao2 and G. V. Nagesh Kumar1,3

1Department of EEE, GITAM University, Visakhapatnam, India 
2Department of EEE, AUCE (A), Andhra University, Visakhapatnam, India
3Department of EEE, Vignan’s Institute of Information Technology, Visakhapatnam, India


Received: March 27, 2017
Accepted: January 27, 2018
Publication Date: June 1, 2018

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The objective of this study is to align the rotor position at the center and maintain less eccentric rotor displacements when bearingless switched reluctance motor (BSRM) is subjected to different loads. In this paper a PID controller is proposed which maintains a stable magnetically levitated rotor position and displacements even on the application of sudden loads to the rotor shaft. As a first step, the rotor is displaced in the four quadrants in the air gap and is successfully pulled back to the center position with the help of the proposed suspension PID controller along with asymmetric converter, hysteresis controller, and rotor displacement sensors. The second step is to run the motor at rated speed by sending phase currents through the PI controller along witha phase hysteresis controller. The third step is the sudden application of torque and suspension loads to the rotor owing to which, the rotor is subjected to eccentric displacements. However, due to control action in suspension phase current, it is pulled back quickly to the center position. The change of suspension loads has a negligible impact on the torque winding current, net torque, speed of the motor, hence the decoupling control is possible between torque and suspension force control. Simulation studies are conducted in all the cases and the obtained results clearly indicate that the suspension winding forces, suspension currents and rotor displacements in both X and Y-directions are in stable condition.

Keywords: Asymmetric Converter, Bearing Less, Decoupling Nature, Displacement, Hysteresis Controller, Magnetic Suspension


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