Metallic sleeves are widely used to ensure the mechanical integrity of rotors in high-speed permanent magnet (PM) synchronous machines (HSPMSM). However, in traditional high-speed rotors, the PMs which are very weak in tensile stress cannot be well protected by sleeves. Furthermore, the material properties of both the sleeves and PMs cannot be fully used. As a result, the high-speed running range of the machines are limited by the mechanical strength for a given rotor size. In this paper, taking a 230-kW 35-kr/min prototype as an example, the mechanical strength issues of the rotor are investigated by analytical method and finite element analysis (FEA). In order to overcome the unbalanced protective effect of the sleeve and make fully use of the materials, an optimal sleeve, as well as an improved rotor structure, is presented. The comparison results show that the optimized sleeve has well balanced protective effect to the PM as well as good utilization of materials, with a resultant increase in maximum speed of nearly 40% with respect to the prototype.
GeradaD.MebarkiA.BrownN.GeradaC.CavagninoA. and BogliettiA., High-speed electrical machines: Technologies, trends, and developments, IEEE Transactions on Industrial Electronics53(2) (2014), 415–420.
2.
XuY.M.MAiM.WangW.Y. and WangY.D., Composite sheath of high-speed permanent magnet generator with rotor strength constraint, International Journal of Applied Electromagnetics and Mechanics61(2) (2019), 247–262.
3.
ChoH.W.KoK.J.ChoiJ.Y.ShinH.J. and JangS.M., Rotor natural frequency in high-speed permanent-magnet synchronous motor for turbo-compressor application, IEEE Transactions on Magnetics47(10) (2011), 4258–4261.
4.
BianchiN.BolognaniS. and LuiseF., Potentials and limits of high speed PM motors, IEEE Transactions on Industrial Applications40(6) (2004), 1570–1578.
5.
LuomiJ.ZwyssigC.LooserA. and KolarJ.W., Efficiency optimization of a 100-W 500 000-r/min permanent-magnet machine including air-friction losses, IEEE Transactions on Industrial Applications45(4) (2009), 1368–1377.
6.
ArumugamP.XuZ.RoccaA.L.VakilG.DickinsonM.AmankwahE.HamitiT.BozhkoS.GeradaC. and PickeringS.J., High-speed solid rotor permanent magnet machines: Concept and design, IEEE Transactions on Transportation Electrification2(3) (2016), 391–400.
7.
BorisavljevicA.PolinderH. and FerreiraJ.A., On the speed limits of permanent-magnet machines, IEEE Transactions on Industrial Electronics57(1) (2010), 220–227.
8.
UzhegovN.KurvinenE.NergJ.PyrhönenJ.SopanenJ.T. and ShirinskiiS., Multidisciplinary design process of a 6-slot 2-pole high-speed permanent-magnet synchronous machine, IEEE Transactions on Industrial Electronics63(2) (2016), 784–795.
9.
HuangZ.FangJ.LiuX. and HanB., Loss calculation and thermal analysis of rotors supported by active magnetic bearings for high-speed permanent-magnet electrical machines, IEEE Transactions on Industrial Electronics63(4) (2016), 2027–2035.
10.
JangG.H.AhnJ.H.KimB.O.LeeD.H.BangJ.S. and ChoJ.Y., Design and characteristic analysis of a high-speed permanent magnet synchronous motor considering the mechanical structure for high-speed and high-head centrifugal pumps, IEEE Transactions on Magnetics54(3) (2018), 1–6.
11.
TongW.M.SunR.L.ZhangC.WuS.N. and TangR.Y., Loss and thermal analysis of a high-speed surface-mounted PMSM with amorphous metal stator core and titanium alloy rotor sleeve, IEEE Transactions on Magnetics55(6) (2019), 1–4.
12.
FangH.Y.LiD.W.QuR.H.LiJ.WangC. and SongB., Rotor design and eddy-current loss suppression for high-speed machines with a solid-PM rotor, IEEE Transactions on Industry Applications55(1) (2019), 448–457.
13.
AhnJ.H.HanC.KimC.W. and ChoiJ.Y., Rotor design of high-speed permanent magnet synchronous motors considering rotor magnet and sleeve materials, IEEE Transactions on Applied Superconductivity28(3) (2018), 1–4.
14.
KolondzovskiZ.BelahcenA. and ArkkioA., Comparative thermal analysis of different rotor types for a high-speed permanent-magnet electrical machine, IET Electric Power Applications3(4) (2009), 279–288.
15.
KennyB.H.KascakP.E.JansenR.DeverT. and SantiagowW., Control of a high-speed flywheel system for energy storage in space applications, IEEE Transactions on Industrial Applications41(4) (2005), 1029–1038.
16.
ZhangF.DuG.WangT.LiuG. and CaoW., Rotor retaining sleeve design for a 1.12-MW high-speed PM machine, IEEE Transactions on Industrial Applications51(5) (2015), 3675–3685.
17.
HongD.K.WooB.C.LeeJ.Y. and KooD.H., Ultra high speed motor supported by air foil bearings for air blower cooling fuel cells, IEEE Transactions on Magnetics48(2) (2012), 871–874.
18.
AhnJ.H.ChoiJ.Y.ParkC.H.HanC.KimC.W. and YoonT.G., Correlation between rotor vibration and mechanical stress in ultra-high-speed permanent magnet synchronous motors, IEEE Transactions on Magnetics53(11) (2017).
19.
ZwyssigC.RoundS.D. and KolarJ.W., An ultra-high-speed, low power electrical drive system, IEEE Transactions on Industrial Electronics55(2) (2008), 577–585.
20.
PfisterP.D. and PerriardY., Very-high-speed slotless permanent-magnet motors: Analytical modeling, optimization, design, and torque measurement methods, IEEE Transactions on Industrial Electronics57(1) (2010), 296–303.
21.
HuangZ. and FangJ., Multiphysics design and optimization of high-speed permanent-magnet electrical machines for air blower applications, IEEE Transactions on Industrial Electronics63(5) (2016), 2766–2774.
22.
SmithD.J.B.MecrowB.C.AtkinsonG.J.JackA.G. and MehnaA.A.A., Shear stress concentrations in permanent magnet rotor sleeves, in: Proc. XIX Int. Conf. Elect. Mach, 2010, pp. 1–6.
23.
BellK.Y. and AbelS., Optimization of WWTP aeration process upgrades for energy efficiency, Water Practice Technol6(2) (2011), 1–10.
24.
BrucknerR.J., Windage power loss in gas foil bearings and the rotor-stator clearance of high speed generators operating in high pressure environments, in: ASME Turbo Expo, 2009, pp. 263–270.
