1396 *() () (1). (1). () *. 1396/7/18 : 1395/1/14 : :. 1..... : Rotor Design and Analysis of 4/ SRMs to Produce Continuous Torque using Finite Element Method Davood Karamalian (1) _ Behrooz Majidi () _Mohammad Reza Yousefi (3) (1) MSc - Department of Electrical Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran. Davood.karamalian@gmail.com () Assistant Professor - Department of Electrical Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran. bmx@aut.ac.ir (3) Assistant Professor - Department of Electrical Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran. Smart Microgrid Research Center, Najafabad Branch, Islamic Azad University, Najafabad, Iran. mr.yousefi@ieee.org Abstract Electrical and mechanical benefits, simple manufacturing and maintenance of switched reluctance motor make it suitable in industrial and home applications, but the most important drawbacks of switched reluctance motor are discontinuous torque and no self-starting in some rotor positions. In this paper a novel rotor structure is presented and optimized in order to increase positive torque region and eliminate dead-zone in high loads. The torque produced in this proposed SRM is divided into two regions and overlapped in two phases periodically. In order to find the best output character and optimal design, two factors, position and angle of cut edge are optimized. To verify the proposed rotor, torque characteristic, flux path and torque ripple has been analyzed by finite element method and compared with conventional 4/ SRM. The proposed motor has a continuous torque characteristic. Index Terms: Switched reluctance motor; Continuous torque; Finite element method; Dead-zone region. bmx@aut.ac.ir : 13
0-13....[7] 4. -1-4 (1) (4/) (1).[7] (1)...[8] () pcs pcs1 4/ :(1) Fig. (1): 4/ switched reluctance motor.[9] -1..[1]..[].[3].[4]. %50 4/.[5] [6] 4/. 14
1396 :(4) Fig. (4): Characteristic of torque-rotor position : [9] :() Fig. (): Converter of -phase switched reluctance motor -3- θ 0 (3) r : π θ rp = ( ) P π θ rs = ( ) ( 3) q.p r Ps q = ( 4) θ rs θ rp : q θ = θ + θ θ θ ( θ θ1) 0 ( 5) 0 rs 1 rs : θ 4π rp θ θ1 = θ rs = ( 6) q PsPr θ 1 θ (3) : θ rs 4π β s min = Ps = 4, Pr = β s = 90 ( 7) Pr.Ps β s min 4 4/. -4-..[1] [11] 15 w fld 1 1 dl ( θ) = Li Te = i ( 1) d ( θ) T e w fld (1) L i. (3) (1) L-θ θ. dl ( θ ) > 0 d ( θ ). [10] :(3) Fig. (3): Characteristic of stator per phase inductance vs rotor position of motor -- (4) 58. 3.
0-13. -3. M1-4G L D 4 3 (1). (11) (8).[10] [16] π T = ( B aν.ac )D L ( 8) β s w = D sin( ) ( 9) 0.5w < b < w ( 10) sy ry 0.5w < b < 0.75 w ( 11) T N DL 1 ph e = k 1µ 0 [ ] i ( 1) 8 l g T B aν 6 5 ac / 7 w 9.[16] N ph 8 (1). µ 0. -5-..[14] [13]. 3. -1-3 NEMA4 :[15] -1. -. 8 8 11 0/17 40 54 105 13/5 110 :(1) Table. (1): Dimension of proposed motor 10 11 A θ B 1 dl. dl T e A B T e = i ( + ) = Te1 + dθ dead zone d θc dead zone = 90 θc Te 1 θdead zone θ c T e ( 13) 16 --3 4/ (4) θ c = 54 90 (7) θdead zone = 90 θc (13) (5)
1396 P (6) Y P opt = (13/5 30). θ A θ --4 (5) (3 6) P 1.. (7) :(7) Fig. (7): Torque-rotor position characteristic for various values of angle θ B A. B B. 6 P :(5) Fig. (5): Proposed rotor A dl( θ) d( θ) B. -4 A (5) P(X,Y) : θ A P(X,Y) -1-4 (REGION A) X P θ dead zone 13/5. (4/5 35) Y Y. (6) 5 1-5. (8) (9) 1/8. 17 :(6) p Fig. (6): Torque-rotor position characteristic for various values of P coordinate
0-13. :( -10) Fig. (10-b): Torque characteristic in one revolution of rotor ( -10) 1/5 B A.... -6 (14) 1.76 T max T avr 1.39 T min.. 1.5 Tmax Tmin Trip = ( 14) T avr. -7. :(8) Fig. (8): Flux distribution of proposed motor M1-4G :(9) Fig. (9): B-H curve of M1-4G ( -10) 10 110.. (9) 1/5. :( -10) Fig. (10-a): Torque characteristic in one phase excitation of proposed motor 18
1396 1. Dead zone region. Duty cycle 3. Stator back iron 4. Rotor back iron 5. Specific magnetic loading 6. Specific electrical loading 7. Stator pole width 8. Permeability 9. Turn per phase 10. Stack length 11. Turn per pole 1. Finite Element Method(FEM) Maxwell. 6 P = (13/5 30).. References [1] I. Petrov, J. Pyrhonen, "Performance of low-cost permanent magnet material in PM synchronous machines", IEEE Trans. on Industrial Electronics, Vol. 60, No. 6, pp. 131-139, June 013. [] F.J.T.E. Ferreira, G. Baoming, A.T.D. Almeida, "Reliability and operation of high-efficiency induction motors", IEEE Trans. on Industry Applications, Vol. 5, No. 6, pp. 468-4637, Nov./Dec. 016. [3] J. Hur, J.W. Reu, B.W. Kim, G.H. Kang, "Vibration reduction of IPM-Type BLDC motor using negative third harmonic elimination method of air-gap flux density", IEEE Trans. on Industry Applications, Vol. 47, No. 3, pp. 1300-1309, May/June 011. [4] S. Marinkov, B.D.Jager, "Four-quadrant control of 4/ switch reluctance machines", IEEE Trans. on Industrial Electronics, Vol. 63, No. 1, pp. 7393-7403, Dec. 016. [5] J.W. Ahan, H.M. Khoi, D.H. Lee, "Design and analysis of high eed 4/ SRM for an air-blower", Proceeding IEEE/ISIE, pp. 14-146, Bari, Italy, July 010. [6] C. Lee, R. Krishnan, "New designs of a two phase E-core switched reluctance machine by optimization the magnetic structure for a ecific application: concept, design, and analysis", IEEE Trans. on Industry Applications, Vol. 45, No. 5, pp. 1804-1814, Sep./Oct. 009. [7] P.C. Sen, "Principle of electric machines and power electronics", Wiley, Third Edition, 013. [8] N.S. Lobo, E. Swint, R. Krishnan, "M-phase N-segment flux-reversal free stator switched reluctance machines", Proceeding of the IEEE/IAS, pp.1-8, Edmonton, AB, Canada, Oct. 008. [9] S. Prabhu, M. Balai, V. Kamaraj, "Analysis of two phase switched reluctance motor with flux reversal free stator, Proceeding of the IEEE/PEDS, pp. 30-35, Sydney, NSW, Australia, June 015. [10] R. Krishnan, "Switched reluctance motor drives", Boca Raton, FL: CRC Press, 003. [11] P. Bogu, M. Korkosz, A. Powrozek, J. Prokop, "A two phase switched reluctance motor with reduced stator pole arc", Proceeding of the IEEE/EDPE, pp. 31-318, Tatranska Lomnica, Slovakia, Sep. 015. [1] R. Hamdy, J. Fletcher, B.W. Williams, "Bidirectional starting of a symmetrical two phase switch reluctance machine", IEEE Trans. on Energy Conversion, Vol. 15, No., pp. 11-17, June 000. [13] P.T. Hieu, D.H. Lee, J.W. Ahn, "Design of -phase 4/ SRM for torque ripple reduction", Proceeding of the IEEE/ICEMS, pp. 1-6, Sapporo, Japan, Oct. 01. [14] S.G. Oh, R. Krishnan, "Two phase SRM with flux reversal free stator: concept, design and experimental verification", IEEE Trans. on Industry Applications, Vol. 43, No. 5, pp. 147-157, Sep./Oct. 007. [15] C. Lee, R. Krishnan, N.S. Lobo, "Novel tow-phase switch reluctance machine using common-pole E-core structure: concept, analysis and experimental verification", IEEE Trans. on Industry Applications, Vol. 45, No., pp. 1-6, March/April 009. [16] E.S. Hamdi, "Design of small electrical machines", Wiley, First Edition, 1995. 19
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