STAR-CCM+ CM+ and SPE PEED ED for electric ctric machines ines cooling ing analysis ysis Stefan an Holst st
Overvie view SPEED’s own thermal capability consists of simplified circuit models – Good for a first shot – Circuit model allows for quick analysis of duty cycle simulations Ef Efficien iency cy requi uire reme ments, nts, space e and d weight ight restr tric icti tions ons lead d to more re compl plex x machi chine ne and machine hine enclos closure ure designs igns – Identifying hot spots becomes tricky – STAR-CCM+ can show its strength in these models User r should ld bene nefit t as muc uch h as possible ible from om the e work done ne in SPEE EED – Import geometry – Import distribution of heat loads electromagnetic losses – Future: coupled EMAG and thermal analysis in a single tool
Loss ss mechan anisms isms and dist strib ibut ution ion Ohmi mic c heat ating ing in all condu nducti cting ng parts – Windings, laminated rotor and stator core and magnets – Winding/copper losses are usually the largest contributor Hystere eresis is effects ects most stly ly in steel eel parts s Simulat ation ion thes ese effect ects direct ectly ly requi uire res coup upled led transi sien ent t EM EMAG run un – Very costly for a design calculation Not ote: : Loss osses es occu cur r locall lly
Steinm einmetz tz Loss s calculation lation Al Alternativ rnative e to coup upled led simula ulati tion on – Hysteresis and eddy currents are mostly driven by changes in the magnetic field – Get magnetic field for various rotor positions and attribute losses to size of field changes – Strong variation in the teeth Magne nets s shield eld the e rot otor or core re
Work rkflo flow w diagram gram Initial 2D Machine Layout Geometry Import Heat Loads from SPEED •Perform EMAG layout •Meshing automatically specified •Import via STAR-CCM+ file format *.sbd •Perform thermal circuit •Physical setup simulation of duty cycles 10-16 •Surface data needs to be •Either CHT nodes mapped to volume •Or EMAG •Or even coupled
Geome metr try impor port xGDF & & xDEF EF files es contain tain the comple lete e EMAG G set etup in XML Curren ently ly only Geome ometr try impo mport Future e ver ersions sions includ lude e physics ics and d mode dels ls for end-windin indings, s, skew
Cooling ling mechanism anism Ai Air cooled oled – Exterior and interior Spray y cooli oling ng of the e end d windin ndings gs Water er cool oling ing around nd the e stator or – More on that now
Resu sults lts for a c coolin ling g jacket t around und the stat ator or Heat t conduc nducti tion, on, convecti ection on and radiation diation in the e interior erior air 1l/min min water er pum umped ed throu ough gh How How to keep ep the e rot otor or cool ol?
Introdu oduce ce holes es into the e rotor or Four CAD features later we’ve got holes in the rotor Remesh mesh and fur urth ther er itera rati ting ng gives
Data a Mapper er Loss sses s are given en in 2D but ut the e therm rmal l simula ulati tion on is in 3D Data Mapper r fun uncti ction onality ality exten ension ion to fa facilit itate e precis ise e mapping ng even en for skewed ed machi chine nes s will come me with th 7.04 – Improved mapping quality compared to current nearest neighbour interpolation Three ree mappings ings are define ined d here re: – Rotor – Stator – Windings SPEE EED only ly provides vides total otal losses ses in magne nets
Suppor port t for end windin dings gs Examples Ex les so fa far have e been en hand d made de 3D CAD AD cons nstr tructi tions ons
Glimpse pse on the EMAG G solver er Magne netos osta tatic tic run uns s for differen erent t rot otor or positi tion ons
Glimpse pse on the EMAG G solver er Low w freq equenc ency y electr ctro-magne magnetic tic solver er – Frequency/domain size determines applicability An e-machines frequency range might not be allowed in areas like mine detection with far larger length scales Coup upled led transient nsient and d magne netost ostat atic mode ode – Magnetostatic can be coupled with motion to cater for loss calculations Non on-line inear r mater erial ial sup uppor ort – SPEED model import brings in BH-curves – Tabular data or functional description – Isotropic electric conductivity and permeability
EMAG G solver er outlook look Circuit uit – Transient 3D requires feedback from the circuit • Extend circuit capability in BSM for general use – Flux linkage report for electromagnetic circuit elements Field eld simula ulati tion on – Hysteresis modeling • Residual magnetism – Force/Torque calculation – Anisotropy • Electric conductivity and permeability • Infrastructure
Thank nk you Thank k you!
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