Ele lectric M Machi hine ne S Simu mula lation T n Techno - - PowerPoint PPT Presentation

Ele lectric M Machi hine ne S Simu mula lation T n Techno hnolo logy y

Steve H Hartridge Di Director, E , Ele lectric & & H Hyb ybrid V Vehi hicle les

Int Introduction n Todays ys d dema mand nds/Motivations ns EMAG a G and nd T The herma mal mo l modeli ling ng Comb mbine ned w workf kflo low E Example les

Agend nda

Over t the he la last d decade i it i is no noticeable le t tha hat t the here i is a a g growing ng ne need f for e ele lectric ma machi hine nes w with h

• High t

h torque o

• r
• High p

h power d dens nsity a y alo long ng w with a h a

• High e

h efficienc ncy d y dema mand nd o

• r/and

nd

• Reduction i

n in s n size, w , weight ht, c , cost

Leading ng t to

• hi

highe her t temperature g gradient nts w with a h a hi highe her dema mand nd o

• n t

n the he ma materials ls i in g n gene neral, b l, but e esp. .

• n t

n the he i ins nsula lation ma n materials ls

• sho

horter li lifetime me e expectation d n due t to a a hi highe her risk o k of t the herma mal d l dama mages ( (esp. i . in t n the he i ins nsula lation n ma materials ls). .

• A hi

highe her r risk o k of d dema magne netization o n of t the he ma magne nets

Source g graphi hics: N : NREL

Motivation f n for A Ana nalys lysis

Motivation f n for A Ana nalys lysis

Component lifetime estimates [1]:

– 22% of failures due to thermal damages in insulation – 17% further thermal damage in other components

Lifetime me d depend nds o

• n t

n temperature hi history; y; Temperature d depend nds o

• n lo

n losses a and nd c cooli ling ng Insulation lifetime L can be modeled by the Arrhenius chemical equation [2]:

• Montsinger’s rule taken from transformer oil and solid insulation materials shows

that the lifetime L decreases by 50% with increase of temperature T by 10 K [3]: So insulation breakdown is likely to be the problem associated with high

• temperatures. This problem may be tackled by

– either improving the insulation material and allowing the temperatures to rise or – improving the cooling performance of the windings and limiting the maximum temperature.

L ¡ L ¡= ¡ ¡A · · ​𝒇 ​𝒇↑(​𝒃/𝒄 ¡⋅ 𝒃/𝒄 ¡⋅ ¡𝑼 ) L ¡ ¡(T (T ¡ ¡+ ¡ ¡10K) ¡ ) ¡= ¡ ¡0.5 ¡ ¡ ¡ ¡∙ ¡ ¡L(T (T)

Source: [1] Bruetsch, R., Tari, M. Froehlich, K. Weiers, T. and Vogesang, R., 2008. Insulation Failure Mechanisms of Power Generators IEEE, Electrical Insulation Magazine, 24(4) [2] Dakin, T.W., 1948, Electrical Insulation Deterioration Treated as a Chemical Rate Phenomena, AIEE Trans., Part 1, 67 [3] Binder, A., TU Darmstadt, EW, 2008, Script Large Generators & High Power Drives

To accomplish today’s demand the new machine designs have – to eliminate the safety factors of the over-sizing designs of the past – to finally ensure the requested high power densities. The need to have an optimized thermal design besides an optimized electro- magnetic design.

Motivation f n for A Ana nalys lysis

Ele lectric M Machi hine ne S Simu mula lation T n Techno hnolo logy y

Ele lectroma magne netic S Simu mula lation n

• Ele

lectrical/ l/me mecha hani nical p l performa manc nce o

• f

design n

• De

Design s n studies o

• f d

different nt t typ ypes o

• f

ma machi hine ne IM IMD v D vs. B . BDC DC

• Torque a

and nd e efficienc ncy r y requireme ment nts a are me met

• Build

ld e efficienc ncy ma y map f for ma machi hine ne

• De

Detaile led g geome metric d design o n of compone nent nts – – 2 2D/ D/3D D

• Optimi

mize ma magne net p position/ n/sha hape/ ma material l

• Inc

Inclu lude a a s simple le/cond nduction o n only nly the herma mal mo l model l

The herma mal S l Simu mula lation n

• Und

nderstand nd t the he e efficienc ncy o y of t the he c cooli ling ng sys ystem m

• Optimi

mize a a f flo low p paths hs f for a a g given c n cooli ling ng sys ystem m

• Predict ma

maximu mum c m compone nent nt temperatures a at g given d n different nt o

• perating

ng point nts

• Cons

nsider C Cond nduction/ n/convection/ n/ radiation s n sys ystem m

• Inc

Inclu lude t temperature d depend ndent nt pr prope pertie ies s

Coupled Problem Machine Designer/ Electrical Engineer Thermal analyst/ Mechanical engineer

The heat generated inside the motor originates from two main sources: – Electrical losses include

• the

he c copper lo losses - a

• als

lso I2

2 ·R lo

losses - i

• in t

n the he w wind nding ngs

( (he heating ng e effect d due t to c copper r resistanc nce), ,

• core lo

losses a and nd

( (ma magne netic h hys ysteresis ( (~ Bk · f) a and nd e eddy c y current nts ( (~ B2 · f2) i in i n iron c n cores)

• eddy c

y current nt lo losses i in o n othe her p parts o

• f t

the he ma machi hine ne b being ng e ele lectric cond nductive, , e.g .g p perma mane nent nt ma magne nets, e , end nd s shi hield lds, ho , housing ng p parts, … , … – Mechanical losses, such as

• frictiona

nal lo l losses g gene nerated b by t y the he b bearing ngs a as w well a ll as

• wind

ndage lo losses

Losses i in E n Ele lectrical M l Machi hine nes

Conjugate Heat Transfer Analysis of Integrated Brushless Generators for More Electric Engines Marco Tosetti, Paolo Maggiore, Andrea Cavagnino, Senior Member IEEE, and Silvio Vaschetto, Member IEEE Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino – Italy

Brushle hless g gene nerator

The herma mal M l Modeli ling ng i in E n Ele lectrical M l Machi hine nes

Conjugate Heat Transfer Analysis of Integrated Brushless Generators for More Electric Engines Marco Tosetti, Paolo Maggiore, Andrea Cavagnino, Senior Member IEEE, and Silvio Vaschetto, Member IEEE Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino – Italy

Brushle hless g gene nerator

The herma mal M l Modeli ling ng i in E n Ele lectrical M l Machi hine nes

Winding Temperature Stator Core Temperature

Achi hieving ng C Couple led M Models ls

Ele lectroma magne netic S Simu mula lation n The herma mal S l Simu mula lation n

Coupled Problem

• Manu

nual T l Trans nsfer o

• f lo

losses

• Rotor, Stator, Windings
• Homogeneous application
• Mapping of distributed losses
• Segmented by parts
• Maintain distribution of losses
• Typically from Finite element codes
• Codes often use a temperature
• Templa

late b based d design c n codes

• Simple circuit models
• Finite Volume flow/thermal codes
• Homogeneous losses on bodies
• Rotor
• Stator
• Windings
• Heterogeneous losses
• Map between grids

Losses i in E n Ele lectric M Machi hine nes

Homogeneous application of losses per component

– Copper losses = 43 W – Iron losses stator = 345 W – Magnet losses = 0.74 W

Heterogeneous application of losses

– See image

Comparison of Solution

Heterogeneous Homogeneous

Brushle hless DC DC mo motor, 1 , 10KW ma max p power

Losses i in E n Ele lectric M Machi hine nes

Comparison of maximum temperature

Heterogeneous Homogeneous

Heterogeneous “mapped” losses lead to higher maximum temperatures

The he B B-f

• field

ld v variation a n allo llows i iron lo n loss estima mation n

– GoFER of 72 rotor positions /elec. revolution – Modified Steinmetz method in SPEED applies also to non sinusoidal currents

Front nt p part o

• f t

the he t tooth s h sees s strong nger f field ld variations ns w whi hich i h is r refle lected i in t n the he hi highe her iron lo n loss d dens nsity y The he i iron lo n loss d dens nsity c y can b n be v visuali lized SPEED D

– Select the “Plot” Tab

Da Data T Trans nsfer t to S STAR-C

• CCM+ -
• Losses

Losses

13 13

Da Data T Trans nsfer t to S STAR-C

• CCM+ - Ge
• Geome

metry y

SPEED g D geome metry f y for: s : stator, s , slo lot w wind nding ngs, , rotor, r , rotor b bars. CAD g D geome metry f y for: e : end nd-w

• wind

nding ngs, e , end nd- ring ngs, a , all no ll non-a n-active c compone nent nts ( (fan, n, ho housing ng, e , etc…)

SPEED > D > S STAR-C

• CCM+ Ind

Industrial E l Example le

Ind Induction ma n machi hine ne, o , overblo lown w n with f h fan o n on t n the he s sha haft

– SPEED Model > loss distribution – STAR-CCM+ > Temperature profiles

• Rotor B

Bar Av Avg=148.4 .4 C C, E , End nd R Ring ng 1 1 Av Avg=144.7 .7 C C, E , End nd R Ring ng 2 2 Av Avg=147.6 .6 C C

• Sha

haft M Min T n Temp=55.8 .8 C C, S , Sha haft M Max T Temp=148.3 .3 C C

• SPEED mo

D model w l with r h rotor t temp @ @ 1 148 C C r requires 5 52.5 .5 % % o

• f c

copper cond nductivity f y for c cons nsistent nt lo losses a and nd p performa manc nce a at t thi his lo load p point nt. .

16 16

Simu mula lation S n Steady S y State T Temperatures

1 1 2 2

Comparison w n with M h Measureme ment nts

• Cli

lient nt me measureme ment nts o

• n a

n aux a and nd ma main w n wind nding ng a at 2 2 c circumf mferent ntial lo l locations ns, , both f h for t the he f fan ( n (cold ld s side) a and nd e exha haust ( (ho hot s side) o

• f t

the he e end nd w wind nding ng. .

• Comp

mpare w with me h mean a n and nd s stand ndard d deviation o n of t temp mperature i in o n outer 5 5mm mm of e

end nd- wind nding ng End Winding 2 (cold side)

Measurement Simulation % Error Mean 91.5 C 93.1 C 1.74 % STD 1.88 C 2.14 C

End Winding 1 (hot side)

Measurement Simulation % Error Mean 111.4 C 111.9 C 0.45 % STD 3.03 C 1.30 C

SPEED > D > S STAR-C

• CCM+ Ind

Industrial E l Example le

Heat F Flo low: R : Rotor a and nd S Stator

SPEED > D > S STAR-C

• CCM+ Ind

Industrial E l Example le

SPEED > D > S STAR-C

• CCM+ W

Workf kflo low

Import SPEED geometry and surrounding CAD for non-active components in to STAR-CCM+ Compute electromagnetic losses in SPEED for specific load point and import into STAR-CCM+ Define appropriate physics and boundary conditions in STAR- CCM+ Solve conjugate heat tranfer problem for specific load point in STAR- CCM+ Specify new

• perating point and

recompute temperatures

Low speed, high torque…………………High speed, low torque

Wha hat i if s study: V y: Vent nted S Stator i iteration n

– New CAD geometry imported – Remeshed and case rerun

SPEED > D > S STAR-C

• CCM+ Ind

Industrial E l Example le

End Winding 2 (cold side)

Orig Design Vented Stator % Mean 93.1 C 76.6 C 17.7 % STD 2.14 C 1.63 C

End Winding 1 (hot side)

Orig Design Vented Stator % Mean 111.9 C 85.9 C 23.2 % STD 1.30 C 0.97 C

Copper w wind nding ng mo modele led w with t h temperature d depend ndent nt r resistivity, r , result lts in hi n highe her lo local he l heating ng w whe here t the he c coil i l is ho hotter. . Vent nted s stator s sho hows r reduction i n in c n coil t l temp a and nd t total he l heat lo load f from 1 m 197 W t to 1 180 W W o

• f c

copper lo losses. .

Temperature De Depend ndent nt R Resistivity o y of Copper W Wind nding ng

SPEED > D > S STAR-C

• CCM+ W

Workf kflo low

Import SPEED geometry and surrounding CAD for non-active components in to STAR-CCM+ Compute electromagnetic losses in SPEED for specific load point and import into STAR-CCM+ Define appropriate physics and boundary conditions in STAR- CCM+ Solve conjugate heat tranfer problem for specific load point in STAR- CCM+ Specify new load point and recompute temperatures Change Geometry and recompute

JMAG > G > S STAR-C

• CCM+ E

Example le

Low speed: 600 rpm Loss density Copper loss density distribution JMAG Iron loss density distribution JMAG Magnet loss density distribution JMAG

Low speed Medium speed High speed

Low speed: 600 rpm High speed: 8,000 rpm Mapped imported heat loss distribution STAR-CCM+ Temperature distribution STAR-CCM+

JMAG > G > S STAR-C

• CCM+ E

Example le

SPEED p D provides i ini nitial d l design n

– Data export for further electromagnetic and thermal analysis

PC- FEA

FE c calc lcula lation n

– For detailed EMAG and loss calculation and export of loss data

STAR-C

• CCM+ c

cooli ling ng a ana nalys lysis

– Conjugate heat transfer using liquid and/or gaseous coolants – Import of thermal loading from EMAG tool

• 2D or 3D Loss distribution data is

mapped onto STAR-CCM+ grid

Comb mbine ned W Workf kflo low

Links nks w with o h othe her F FE s suppli lier: : JMAG (JSOL, Japan) and FLUX (Cedrat, France)

3. . Run thermal calculations

in Motor-CAD to check the model

2. . FE-analysis and fitting

• f the analytical model

5. . Transfer of the heat loss distri-

bution from the FE-analysis to STAR-CCM+ via the sbd-file FE-grid SPEED FV-grid STAR-CCM+

1.

• 1. Creation of the

Motor-CAD model based on geometry parameters and winding scheme or import from SPEED

Data transfer

4.

• 4. Preparation of the geometry

in STAR-CCM+ by running a Java script

• 7. Solving and post processing

in STAR-CCM+

6. . Mapping process for rotor and stator heat

losses is carried out separately and auto- matically with transfer of the values from neighbor grid node in SPEED to STAR- CCM+

The herma mal M l Modeli ling ng ( (7)

Links nks w with M h Motor-C

• CAD (Motor-Design, UK)

STAR-C

• CCM+ E

EMAG s G solv lver

Appli lications ns o

• ften a

n allo llow 2 2D D reduction n Availa lable le i in S n STAR-C

• CCM+ 8

8.0 .06 Vali lidated w with P h PC-F

• FEA

Achi hieving ng C Couple led M Models ls

Ele lectroma magne netic S Simu mula lation The herma mal S l Simu mula lation n

Coupled Problem

Solution Progress

EMAG Solution Thermal Solution EMAG Solution Thermal Solution

It Iterations ns It Iterations ns It Iterations ns It Iterations ns

EMAG Solution

• Mapping of distributed losses
• Heterogeneous losses
• Map between grids

Int Introduction n Todays ys d dema mand nds/Motivations ns EMAG a G and nd T The herma mal mo l modeli ling ng Comb mbine ned w workf kflo low E Example les

Conc nclu lusions ns

Ele lectric M Machi hine ne S Simu mula lation T n Techno hnolo logy y

Steve H Hartridge Di Director, E , Ele lectric & & H Hyb ybrid V Vehi hicle les

Besides CD-adapco internal material this presentation is based on the following publications:

• Bauarten von elektrischen Antrieben und deren Kühlung, Verluste, Vor- und Nachteile, Univ.-Prof. Dr. phil. Dr. techn. habil. Harald Neudorfer,

Traktionssysteme Austria GmbH, Kolloquium Elektrische Antriebe in der Landtechnik, Wieselburg, 26. Juni 2013 – Austria

• Keith R Pullen, Professor of Energy Systems, Brunthan Yoheswaren, PhD Researcher Energy and Transport Research Centre School of Engineering and

Mathematical Sciences, Cooling of Electrical Machines, EMTM ’13, , 12 September 2013 ▪ Nottingham University – UK

• Conjugate Heat Transfer Analysis of Integrated Brushless Generators for More Electric Engines Marco Tosetti, Paolo Maggiore, Andrea Cavagnino, Senior

Member IEEE, and Silvio Vaschetto, Member IEEE, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino – Italy

• Electric Motor Thermal Management, U.S. Department of Energy, Kevin Pennion, May 11, 2011 – US
• End Winding Cooling in Electrical Machines, Christopher Micallef, BEng (Hons), PhD Thesis submitted to the University of Nottingham, September 2006 –

UK

• Script Large Generators & High Power Drives, Prof. habil. Dr.Ing. A. Binder, A., TU Darmstadt, Inst. f. Elektrische Energiewandlung, 2008 – Germany