Four Quadrant Control of Rotor Displacements of Bearingless Switched Reluctance Motor under Eccentric Fault Conditions

Nageswara Rao  Pulivarthi; G. V.  Siva Krishna Rao; G. V.  Nagesh Kumar

doi:10.6180/jase.201806_21(2).0007

Four Quadrant Control of Rotor Displacements of Bearingless Switched Reluctance Motor under Eccentric Fault Conditions

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 Kumar^1,3

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

Download Citation: ||https://doi.org/10.6180/jase.201806_21(2).0007

ABSTRACT

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

REFERENCES

[1] Krishnan, R., Arumugan, R. and Lindsay, J. F., “Design Procedure for Switched-reluctance Motors,” IEEE Transactions on Industrial Applications, Vol. 24, pp. 456–461 (1988). doi: 10.1109/28.2896
[2] Miller, T. J. E., Switched Reluctance Motors and Their Control, Magna Physics Publishing and Clarendon Press, UK, Oxford (1993).
[3] Ohyama,K., Naguib, M.,Nashed, F., Aso, K., Fujii, H. and Uehara, H., “Design Using Finite Element Analysis of a Switched Reluctance Motor for Electric Vehicle,” Journal of Power Electronics, Vol. 6, No. 2, pp. 163171 (2006).
[4] Ayari, S., Besbes, M., Lecrivain, M. and Gabsi, M., “Effectes of the Air Gap Eccentricity on the SRM Vibrations,” Proceedings of International Conference on Electric Machines and Drives, pp. 138140 (1999). doi: 10.1109/IEMDC.1999.769052
[5] Bosch, R., “Development of a Bearingless Electric Motor,” Proceedings of International Conference on Electric Machines, ICEM-88, Pisa, Italy, pp. 373375 (1988).
[6] Bichsel, J., “The Bearingless Electrical Machine,” Proceedings of 4th International Symposium on Magnetic Suspension Technology, NASA/CP-1998-207654, pp. 4963 (1998).
[7] Takemoto, M., Chiba, A., Akagi, H. and Fukao, T., “Suspending Force and Torque of a Bearingless Switched Reluctance Motor Operating in a Region of Magnetic Saturation,”Conference Record of IEEE-IAS Annual Meeting, pp. 35–42 (2002).
[8] Takemoto, M., Shimada, K. and Chiba, A., “A Design and Characteristics of Switched Reluctance Type Bearingless Motors,” 4th International Symposium on Magnetic Suspension Technology, NASA/CP-1998-207654, pp. 4963 (1998).
[9] Takemoto, M., Chiba, A. and Fukao, T., “ANew Control Method of Bearingless Switched Reluctance Motors Using Square-wave Currents,” Proceedings of the 2000 IEEE Power Engineering Society Winter Meeting, Singapore, CD-ROM, pp. 375380 (2000). doi: 10.1109/PESW.2000.849993
[10] Takemoto, M., Chiba, A. and Fukao, T., “A Feed-forward Compensator for Vibration Reduction Considering Magnetic Attraction Force in Bearingless Switched Reluctance Motors,” Proceedings of the International Symposium on Magnetic Bearings, ETH Zurich, pp. 395400 (2000).
[11] Takemoto, M., Suzuki, H. and Chiba, A., “Improved Analysis of a Bearingless Switched Reluctance Motor,” IEEE Transactions on Industrial Applications, Vol. 37, No. 1, pp. 2634 (2001). doi: 10.1109/28. 903123
[12] Takemoto, M., Chiba, A. and Fukao, T., “AMethod of Determining Advanced Angle of Square-wave Currents in a Bearingless Switched Motor,” IEEE Transactions on Industrial Applications, Vol. 37, No. 6, pp. 17021709 (2001). doi: 10.1109/28.968181
[13] Takemoto, M., Chiba, A. and Suzuki, H., “Radial Force and Torque of a Bearingless Switched Reluctance Motor Operating in a Region of Magnetic Saturation,” IEEE Transactions on Industrial Applications, Vol. 40, No. 1, pp. 103112 (2004). doi: 10.1109/TIA.2003. 821816
[14] Chen, L. and Hofman, W., “Analytically Computing Winding Currents to Generate Torque and Levitation Force of a New Bearingless Switched Reluctance Motor,”Proceedings of the 12th International Power Electronics and Motion Control Conference, Portoroz Slovenia, pp.10581063(2006).doi:10.1109/EPEPEMC. 2006.4778541
[15] Wang, H. J., Lee, D. H. and Ahn, J. W., “Novel Bearingless Switched Reluctance Motor with Hybrid Stator Poles: Concept, Analysis, Design and Experimental Verification,” The Eleventh International Conference on Electrical Machines and Systems, pp. 33583363 (2008).
[16] Lee, D. H. and Ahn, J. W., “Design and Analysis of Hybrid Stator Bearingless SRM,” Journal of Electrical Engineering & Technology, Vol. 6, No. 1, pp. 94 103 (2011). doi: 10.5370/JEET.2011.6.1.094
[17] Lee, D. H., Lee, Z. G., Liang, J. N., and Ahn, J. W., “Single-phase SRM Drive with Torque Ripple Reduction and Power FactorCorrection,” IEEETransactions on Industrial Applications, Vol. 43, No. 6, pp. 1578– 1587 (2007). doi: 10.1109/TIA.2007.908162
[18] Wang, H. J., Design and Control of a Novel Bearingless Switched Reluctance Motor, Ph. D. Dissertation, Industrial System Engineering of the Kyungsung University, Busan, Korea, June (2009).
[19] Xu, Z. Y., Lee, D. H. and Ahn, J. W., “Control Characteristics of 8/10 and 12/14 Bearingless Switched Reluctance Motor,” The 2014 International Power Electronics Conference. doi: 10.1109/IPEC.2014.6869708
[20] Torkaman, H., Moradi, R. and Hajihosseinlu, A., “A Comprehensive Power Loss Evaluation for Switched Reluctance Motor in Presence of Rotor Asymmetry Rotation: Theory, Numerical Analysis and Experiments,” Proceedings of Energy Conversion and Management, Vol. 77, pp. 773783 (2014). doi: 10.1016/ j.enconman.2013.10.021
[21] Hwu, K. I., “Applying POWERSYS and SIMULINK to Modeling Switched Reluctance Motor,” Tamkang Journal of Science and Engineering, Vol. 12, No. 4, pp. 429438 (2009). doi: 10.6180/jase.2009.12.4.07
[22] Wang, X. L., Ge, B. M., Wang, J. and Ferreira, Fernando J. T. E., “Radial Force Analytic Modeling for a Novel Bearing Less Switched Reluctance Motor When Considering Rotor Eccentricity,” Taylor & Francis, ISSN: 1532-5008, Vol. 42, No. 6, pp. 544553 (2014). doi: 10.1080/15325008.2014.880968