HYBRID EXCITATION SYNCHRONOUS MACHINES (HESMs) FOR ISLAND OPERATION

Transcription

1 Yliopiston kampusalue HYBRID EXCITATION SYNCHRONOUS MACHINES (HESMs) FOR ISLAND OPERATION Katteden Kamiev Janne Nerg Juha Pyrhönen

2 CONTENTS Introduction Classification Mechanical Considerations Radial Flux Machines ExampleMachine FiniteElementAnalysis Conclusion References

3 INTRODUCTION Boundary conditions set e.g. by the marine classification societies The generator voltage must remain within ±10% in all cases The generator sustainable short circuit current must be three time the rated current at least for two seconds Short circuit current depends on the induced voltage and the direct axis inductance I sc, pu = E L f,pu d,pu = 3 I pu, n, where E f,pu is the induced per unit voltage and L d,pu is the per unit synchronous inductance.

4 CLASSIFICATION of HESMs Combining excitation sources series hybrid excitation parallel hybrid excitation Locations of PMs and excitation coils

5 Classification of HESMs PM+EW PMs in the Rotor PMs in the Stator EW in the Rotor (Brushes/ Brushless) EW in the Stator (Brushless) EW in the Machine s End (Brushless) EW in the Stator (Brushless)

6 Classification of HESMs PMs and excitation coils are located on the rotor side. [4]-[7] Combination Rotor Hybrid Excitation Machine (CRHE) Synchronous/Permanent Magnet Hybrid AC Machine

7 Classification of HESMs PMs are in the rotor and excitation coils are in the stator. [8] PMs are in the rotor side and excitation coils are in the machine s end. [9] PMs and excitation coils are in the stator. [10] Consequent Pole PM Hybrid Excitation Machine (CPPM) Hybrid Excitation Machine with Powered Iron Core Hybrid Excitation Doubly Salient Machine

8 Classification of HESMs Operation Principle HESM has two excitation sources. One is the PM source that provides the airgap with constant flux and the other one is the EW (DC current) that acts as the flux regulator to adjust the air gap flux distribution. Applications as a generator it may be used in an island operation (alp, island, ship, etc.) as a motor HESM is attractive for traction applications, for example, in electric, hybrid electric and fuel cell vehicles Special Features two excitation sources which can be connected either in series or in parallel location of PMs and excitation coils bi-directional DC current

9 Mechanical Considerations Advantages of radial flux vs. axial flux construction The rotor of a radial flux machine may be more rugged than the rotor of an axial flux machine Ideally, radial flux machine produces no axial forces Radial flux machine is easier to cool as the rotor can in some cases be built as hollow Damper winding is easier to arrange in a radial flux machine The radial flux rotor dimensions may easily be adjusted to produce a suitable inertia for the prime mover

10 Radial Flux Machines The advantages of the SPM vs VPM SPM - Utilizes the PM material best - Magnets mechanically vulnerable -Damper winding construction is complicated - Low volume of magnets because of only small magnet stray flux - Good damper properties VPM - High air gap flux density - High efficiency - High armature reaction - Mechanically rugged -Higher magnet stray losses increase the volume of magnets higher magnet price - Good damper properties a) b) c) d) e) Different rotor constructions of radial flux machines. (a) Rotor-surface-mounted magnets, (b) magnets embedded in the surface, (c) pole shoe rotor, (d) tangentially embedded magnets, (e) radially embedded magnets, (f) two magnets per pole in the V position. f)

11 EXAMPLE MACHINE Structure Design specifications Parameter Value Unit Phase number, m 3 - Nominal power, P n 400 kw Nominal voltage, U n 400 V Nominal current, I n 725 A Main geometry data Parameter Value Unit Air gap diameter, D s 750 mm Length, l 400 mm Number of PMs per pole 2 - Power factor, cosφ Rotational speed, n 750 rpm Frequency, f 50 Hz Cross-section view Number of pole pairs, p 4 -

12 EXAMPLE MACHINE Operation Principal PM EW Magnetic path of the PM flux: N pole of the PM PM pole body air gap stator tooth stator yoke stator tooth air gap PM/EW pole body S pole of the neighbour PM/own pole to form a loop. S N S N N S Magnetic flux paths due to PMs (blue lines) and excitation coils (red lines) S N S N N S Magnetic path of the flux due to the electric excitation: pole of the electric excitation S pole of the neighbour PM PM pole air gap stator tooth stator yoke stator tooth air gap electrically excited pole to form a loop. E = E PM + E f

13 Finite Element Analysis Flux lines of the HESM Positive excitation current Zero excitation current

14 Finite Element Analysis Positive DC Zero DC Negative DC Positive DC Zero DC Negative DC Induced phase voltage [V] t [s] Armature winding EMF waveforms Normal flux density [T] x [mm] Air gap flux density distributions

15 Finite Element Analysis Short-circuit current as a function of time

16 CONCLUSION HESMs - combine advantages of PM machines and traditional synchronous machines - have different constructions - have good flux control capability - can increase the short-circuit current

17 REFERENCES [1]. Hybrid Excitation Synchronous Machines: Energy-Efficient Solution for Vehicles Propulsion Amara, Y.; Vido, L.; Gabsi, M.; Hoang, E.; Hamid Ben Ahmed, A.; Lecrivain, M.; Vehicular Technology, IEEE Transactions on Volume 58, Issue 5, Jun 2009 Page(s): Digital Object Identifier /TVT [2]. Direct control of air-gap flux in permanent-magnet machines J. S. Hsu, IEEE Trans. Energy Convers., vol. 15, no. 4, pp ,Dec [3]. A new axial flux surface mounted permanent magnet machine capable of field control M. Aydin, S. Huang, and T. A. Lipo, in Conf. Rec. IEEE IAS Annu. Meeting, 2002, vol. 2, pp [4]. A synchronous/permanent magnet hybrid AC machine Xiaogang Luo; Lipo, T.A.;Energy Conversion, IEEE Transaction on Volume 15, Issue 2, June 2000 Page(s): Digital Object Identifier / [5]. Trial production of a hybrid excitation type synchronous machine N. Naoe and T. Fukami, Electric Machines and Drives Conference, IEMDC IEEE International, pp ,2001.

18 REFERENCES [6]. Design and test of permanent magnet synchronous motor with auxiliary excitation winding for electric vehicle application G. Henneberger, J. R. Hadji-Minaglou, and R. C. Ciorba Proc. Eur. Power Electron. Chapter Symp., Lausanne, Switzerland, Oct. 1994, pp [7]. A double excited synchronous machine for direct drive application - Design and prototype tests D. Fodorean, A. Djerdir, I. A. Viorel, and A. Miraoui, IEEE Trans. Energy Convers., vol. 22, no. 3, pp , Sep [8]. Consequent-pole permanent-magnet machine with extended field-weakening capability Tapia, J.A.; Leonardi, F.; Lipo, T.A.; Industry Applications, IEEE Transactions on Volume 39, Issue 6, Nov.-Dec Page(s): Digital Object Identifier /TIA [9]. Hybrid excitation machines with powdered iron core for electrical traction drive applications Kosaka, T.; Matsui, N.; Electrical Machines and Systems, ICEMS International Conference on Oct Page(s): [10]. Static characteristics of a novel hybrid excitation doubly salient machine Chen Zhihui; Sun Yaping; Yan Yangguang; Electrical Machines and Systems, ICEMS Proceedings of the Eighth International Conference on Volume 1, Sept Page(s): Vol. 1

19 THANK YOU!