Eccentricity faults compensation in SRMs by counterbalancing ampere turns in facing poles

In this paper, a new eccentricity compensation method for Switched Reluctance Machines (SRMs) is presented. Eccentricity faults are very common in these machines; nevertheless there are little literatures addressing the control and compensation on this issue. It is theoretically shown that the occurrence and growth of the eccentricity fault change the amplitude of radial forces (RF) exerted on the rotor and accordingly the amplitude of the unbalanced magnetic force (UMF) is increased, these RFs can be controlled to compensate the fault. In this regard, the dependency of RF on variation of number of turns for stator coils and fault level is demonstrated analytically and principle of the new compensation strategy is introduced as well. This strategy is implemented on a SRM utilizing Finite Element Method (FEM). This approach is accomplished through switching among the various arrangements in the number of turns for the coils on the stator poles; hence, UMF is controlled without additional auxiliary coils.

[1]  Mehrdad Ehsani,et al.  Artificial intelligence approach to controlling SRM drives with manufacturing imperfections , 1996, Proceedings 1996 IEEE Conference on Emerging Technologies and Factory Automation. ETFA '96.

[2]  U. Lundin,et al.  Reduction of Unbalanced Magnetic Pull in Synchronous Machines due to Parallel Circuits , 2011, IEEE Transactions on Magnetics.

[3]  Sheng-Ming Yang,et al.  Instantaneous shaft radial force control with sinusoidal excitations for switched reluctance motors , 2007, Conference Record of the 2004 IEEE Industry Applications Conference, 2004. 39th IAS Annual Meeting..

[4]  Xiaoyong Zhu,et al.  Calculation and remedial strategy of radial force of switched reluctance motors with eccentricity , 2008, 2008 International Conference on Electrical Machines and Systems.

[5]  E. Afjei,et al.  Magnetostatic Field Analysis Regarding the Effects of Dynamic Eccentricity in Switched Reluctance Motor , 2009 .

[6]  A.C. Smith,et al.  Calculation of UMP in induction motors with series or parallel winding connections , 1994, IEEE Power Engineering Review.

[7]  Ebrahim Afjei,et al.  Radial Force Characteristic Assessment in a Novel Two-Phase Dual Layer Srg Using FEM , 2012 .

[8]  A. Arkkio,et al.  Comparison of the Unbalanced Magnetic Pull Mitigation by the Parallel Paths in the Stator and Rotor Windings , 2007, IEEE Transactions on Magnetics.

[9]  Ebrahim Afjei,et al.  New Double-Layer-per-Phase Isolated Switched Reluctance Motor: Concept, Numerical Analysis, and Experimental Confirmation , 2012, IEEE Transactions on Industrial Electronics.

[10]  E. Afjei,et al.  Misalignment fault analysis and diagnosis in switched reluctance motor , 2011 .

[11]  Ebrahim Afjei,et al.  Comprehensive Magnetic Field-Based Study on Effects of Static Rotor Eccentricity in Switched Reluctance Motor Parameters Utilizing Three-Dimensional Finite Element , 2009 .

[12]  T.J.E. Miller,et al.  Faults and unbalance forces in the switched reluctance machine , 1993, Conference Record of the 1993 IEEE Industry Applications Conference Twenty-Eighth IAS Annual Meeting.

[13]  Ebrahim Afjei,et al.  Magnetostatic Field Analysis and Diagnosis of Mixed Eccentricity Fault in Switched Reluctance Motor , 2011 .

[14]  Ebrahim Afjei,et al.  HYBRID METHOD OF OBTAINING DEGREES OF FREEDOM FOR RADIAL AIRGAP LENGTH IN SRM UNDER NORMAL AND FAULTY CONDITIONS BASED ON MAGNETOSTATIC MODEL , 2010 .

[15]  Jian Li,et al.  Analysis of Rotor Eccentricity in Switched Reluctance Motor With Parallel Winding Using FEM , 2009, IEEE Transactions on Magnetics.

[16]  Sheng-Ming Yang,et al.  An Approach to Producing Controlled Radial Force in a Switched Reluctance Motor , 2007, IEEE Transactions on Industrial Electronics.

[17]  E. Afjei,et al.  Static, Dynamic, and Mixed Eccentricity Faults Diagnosis in Switched Reluctance Motors Using Transient Finite Element Method and Experiments , 2012, IEEE Transactions on Magnetics.