APPLICATIONS OF HIGH ENERGY DENSITY PERMANENT MAGNETS W. Kappel - - PowerPoint PPT Presentation

▶
applications of high energy density permanent magnets
SMART_READER_LITE
LIVE PREVIEW

APPLICATIONS OF HIGH ENERGY DENSITY PERMANENT MAGNETS W. Kappel - - PowerPoint PPT Presentation

Mar 21, 2024 753 likes •1.42k views

APPLICATIONS OF HIGH ENERGY DENSITY PERMANENT MAGNETS W. Kappel R&D Institute for Electrical Engineering ICPE-Advanced Research Splaiul Unirii 313, sector 3, Bucharest, Romania European School on Magnetism,September 8-18 th , Cluj Napoca

slide-1
SLIDE 1

APPLICATIONS OF HIGH ENERGY DENSITY PERMANENT MAGNETS

European School on Magnetism,September 8-18th, Cluj Napoca

  • W. Kappel

R&D Institute for Electrical Engineering ICPE-Advanced Research Splaiul Unirii 313, sector 3, Bucharest, Romania

slide-2
SLIDE 2

Magnetic Materials

European School on Magnetism,September 8-18th, Cluj Napoca

hard/soft

slide-3
SLIDE 3

How works a PM?

European School on Magnetism,September 8-18th, Cluj Napoca

min

1 1 2 2

mext m

m m m m m m mext t

W BHdv

W B H V B H V W

∞−

=

= = − = −

∫

final mext m initial

W BHdv Fdl

∞−

= =

∫ ∫

slide-4
SLIDE 4

The highest loading energy of a PM

European School on Magnetism,September 8-18th, Cluj Napoca

max min

1 max( ) ( ) 2

m t

W B H V =

min

( ) / 50 /

t

W mass J kg =

Example: for NdFeB-PM with

max

: Comparison

car battery 12

/ 60 V Ah

4

10 /

el

w J kg =

slide-5
SLIDE 5

Permanent magnets

European School on Magnetism,September 8-18th, Cluj Napoca

slide-6
SLIDE 6

High energy permanent magnets

European School on Magnetism,September 8-18th, Cluj Napoca

slide-7
SLIDE 7

Working at high temperature

European School on Magnetism,September 8-18th, Cluj Napoca

slide-8
SLIDE 8

Working temperature

European School on Magnetism,September 8-18th, Cluj Napoca

MFS 350 sintering 2000 1.06 215 Sm2Co17 MFS 250 sintering 2000 0.93 170 SmCos Ugimag 250 sintering 2400 0.64 80 SmGdCo5 MFS[ 220 sintering 2800 1.11 240 NdFeB GM 150 hot worked 1120 1.37 360 NdFeB-MQIII GM 200 densified 1600 0,80 112 NdFeB-MQII General Motors 125 bonded 1200 0.61 64 NdFeB/MQI Vacuumschmelze 210 sintering 3260 1.00 190 NdFeB Shin Etsu 180 sintering 2387 1.17 263 NdFeB Shin Etsu 80 sintering 875 1.40 390 NdFeB Producer Highest working
  • Temp. (°C)
Manufac-turing method jHc (kA/m) Br (T) (BH)max (kJ/m3) Permanent magnet Properties of some Re-TM permanent magnets
slide-9
SLIDE 9

Working at high temperatures

Linear approximation:

max max

( ) ( ) [1 ( )]

  • BH
  • BH

BH T T α = + −

Where:

BH I H

α α α = +

Two PM at Te:

max1 max 2

( ) ( ) BH BH =

at

12 12 1 2

1

e BH BH

k T k α α − ∆ = −

, k12 = (BH)max1o /(BH)max2o

Exemple Alnico IUNDK8AA,

3 max1

( ) 100 / BH kJ m =

,

1

0.04% /

BH

K α = −

NdFeB

3 max2

( ) 300 / BH kJ m =

,

2

0.70% /

BH

K α = −

=>

100o

e

T C ∆ =

European School on Magnetism,September 8-18th, Cluj Napoca

slide-10
SLIDE 10

Working at high temperatures

cI

  • r

H I µ >>

Reversible losses if: We define

max : cI

  • r

T H I µ =

max

1

I H

k T kα α − ∆ = −

from which:

/

ro

  • cIo

k I H µ =

,

max max

1/ 1

H

k T k T α → ⇒ ∆ → − → ⇒ ∆ →

If

1 2 max1 max 2

/ 1 k k T T > ⇒ ∆ ∆ <

That means

For two PM having the same coercivity, the highest working temperature has the PM with the lower remanence (sintered /bonded)

European School on Magnetism,September 8-18th, Cluj Napoca

max

200 ) T K ⇒ ∆ =

1

(1/ 0.005 200 K K

− =

slide-11
SLIDE 11

PM worldwide

European School on Magnetism,September 8-18th, Cluj Napoca

+ - PRCo; * - NdFeB; # - Ferrite; o - Alnico

max

( ) / BH ρ

/ Energy mass =

max

/ cos ( ) / :cos / Energy t BH t kg ρ =

slide-12
SLIDE 12

PM worldwide

European School on Magnetism,September 8-18th, Cluj Napoca

slide-13
SLIDE 13

Load line

European School on Magnetism,September 8-18th, Cluj Napoca

0,

m m m m circuit m

dl H l Hdl H l A µ

−

+ = + Φ =

∫ ∫

1

c circuit m

dl A µ

−

= Λ

∫

c

permeance Λ ≡

1 2

/ /

g m c m g m

k A k A S l l λ = = Λ Λ =

(1 ) 1

H m m

B H M N N S H H NM N µ

→

+ − − = ⎯⎯⎯ →− = − −

slide-14
SLIDE 14

Recoil line/minor histerezis loop

European School on Magnetism,September 8-18th, Cluj Napoca

N – demagnetization factor of the PM

slide-15
SLIDE 15

Ideal Permanent magnet

European School on Magnetism,September 8-18th, Cluj Napoca

(main demagnetisation curve)

1 =

rec

µ

→

) (

r m m

M H B + = µ

An ideal permanent magnet : no irreversibil losses until Hd= intrinsec coercivity!

r

B

) 4 /( ) ( ) (

2 max

µ

r

B BH =

slide-16
SLIDE 16

European School on Magnetism,September 8-18th, Cluj Napoca

slide-17
SLIDE 17

European School on Magnetism,September 8-18th, Cluj Napoca

slide-18
SLIDE 18

European School on Magnetism,September 8-18th, Cluj Napoca

slide-19
SLIDE 19

European School on Magnetism,September 8-18th, Cluj Napoca

S N G

λ λ λ + =

slide-20
SLIDE 20

European School on Magnetism,September 8-18th, Cluj Napoca

slide-21
SLIDE 21

European School on Magnetism,September 8-18th, Cluj Napoca

slide-22
SLIDE 22

European School on Magnetism,September 8-18th, Cluj Napoca

slide-23
SLIDE 23

European School on Magnetism,September 8-18th, Cluj Napoca

slide-24
SLIDE 24

European School on Magnetism,September 8-18th, Cluj Napoca

slide-25
SLIDE 25

Ferrites at low temperatures

European School on Magnetism,September 8-18th, Cluj Napoca

If T→ - 40C, A→A2

  • n the load line

If Hd is applied, A→B at 20C

  • resp. B1 at -40C

If Hd = 0, than B→A1resp B1→A3 along the corresponding recoil lines. If , A1 is not restored because the induction (magnetisation) even become smaller at higher temperature

40 20

T T

−

→

slide-26
SLIDE 26

PM Applications

European School on Magnetism,September 8-18th, Cluj Napoca

slide-27
SLIDE 27

Applications

European School on Magnetism,September 8-18th, Cluj Napoca

Different types of magnetic materials

Type of magn.mate rial

SOFT MAGNETIC MATERIALS HARD MM Magn. memory Magnetostriction material Transport properties Field of appl. E-tron. Sensors EMC E-techn. E-techn. E-tron. IT Actua- tors Sensors Sensors TM- alloys FeSi, Nano &am FeNi Nano FeNi Compo sites M+pol ymers FeSi, FeNi, FeCo, Fe AlNi- Co FeCoZr Permalloy RE-TM NdFeB SmCo NdFeB SmCo TbFeCo RE-Fe2 Ferrit. Mangani tes Soft ferrites Soft ferrites Soft ferrites Magn. liquids Hexa- ferrites Hexa- ferrites Fe2O3, CrO2 LaREMnO3 Thin films Alloys,

  • xids

Metall &oxid systems CoCrTM- RE/CoCr RE-TM Ni Multi- layers M-mu. layers Mu.- lay.+in sulater Metall &oxid systems PtCo RE-TM,TM-TM’ TM/nonmag/ TM,TM/insu l./ TM Nano Am.(Co) Fe2O3 Comp.with exch. interaction Magn. wires TM=3d-transition metal,RE=rare earth,M=metal

slide-28
SLIDE 28

Magnetizing & shapes

European School on Magnetism,September 8-18th, Cluj Napoca

slide-29
SLIDE 29

Applications of high energy PM

Generating mag. fields

European School on Magnetism,September 8-18th, Cluj Napoca

slide-30
SLIDE 30

Cladding magnets/effects

European School on Magnetism,September 8-18th, Cluj Napoca

slide-31
SLIDE 31

PM Applications

Generating mag. fields

European School on Magnetism,September 8-18th, Cluj Napoca

Hallbach (magic) cylinder

) / ln( / 2 ) / 2 sin(

1 2 R

R N N B B

r

π π =

M Coey, D. White, the Ind. Phys. Sept.1998
  • H. A. Leupold,Static Applications, Re-Fe PM, J.M. Coey, Clarondon Press, 1996

[ ]

int

2 ,2

B

B B

∈ −

slide-32
SLIDE 32

Hallbach Cylinder

European School on Magnetism,September 8-18th, Cluj Napoca

Inside notch Outside notch

⎥ ⎦ ⎤ ⎢ ⎣ ⎡ − =

6 1

) )( ( 1 ) ( ) ( R x geometry P B x B

inside inside

⎯→ ← x

2

x x x’ x’

slide-33
SLIDE 33

PM Applications

Magnetic Field

European School on Magnetism,September 8-18th, Cluj Napoca

Applications: PM powder pressing tools for anisotropic PM, built from ferromagnetic steels

(for a sphere, but for a cylinder,

! 2 /

' ' int

M H =

)

slide-34
SLIDE 34

dB/dT=0 with thermocompensating alloys

European School on Magnetism,September 8-18th, Cluj Napoca

TK TK m m

S B BS S B + =

dT dB S S dT dB dT dB S

TK TK m m

+ ⋅ =

( ) ( ) ( )

  • m

mo m

T T B T B − + = α 1

dB/dT = 0

( )

m

  • m

m TK TK

T B S dT dB S α =

Thermoflux

dT dB B S S

TK m mo m TK

α =

TK

S

2 2

( ) R r π − =

slide-35
SLIDE 35

dB/dT=0

European School on Magnetism,September 8-18th, Cluj Napoca

Kw-meter

2 / break Al

M B ρ ฀

,

( 0 ( )(1 ( ))

Al Al Al T

T T T T ρ ρ α = + −

,

0,4%/

Al T

C α = −

2 1 1

1 2

x m

dH F B V dx =

slide-36
SLIDE 36

Field Generator

European School on Magnetism,September 8-18th, Cluj Napoca

L ← →

slide-37
SLIDE 37

Holding magnets

European School on Magnetism,September 8-18th, Cluj Napoca

slide-38
SLIDE 38

Holding magnets

European School on Magnetism,September 8-18th, Cluj Napoca

2

2

L

B F A µ =

1/ R = Λ

slide-39
SLIDE 39
  • Demagnetisation curve

European School on Magnetism,September 8-18th, Cluj Napoca

Φ − Θ

m m m g g s s g s

B S B S B S Φ = = + = Φ + Φ

m m m g g g s

H l H l Θ = = = Θ = Θ

1 /

m m m m m m m m m m m

l l tg R S S B H α λ Θ = = = = = Φ Λ

int g s ext g s

R R R R R R ≡ = +

  • ptimal
  • ptimal

m m

R =

Φ

slide-40
SLIDE 40

Bearings

European School on Magnetism,September 8-18th, Cluj Napoca

2 1 1

1 2

x m

dH F B V dx =

slide-41
SLIDE 41

Axial coupling

European School on Magnetism,September 8-18th, Cluj Napoca

max

( )

geom mag mag

M f BH pV =

slide-42
SLIDE 42

Multiple Radial Coupling

European School on Magnetism,September 8-18th, Cluj Napoca

2 3

~ 10

10

T

n Nm −

slide-43
SLIDE 43

Radial coupling

European School on Magnetism,September 8-18th, Cluj Napoca

2 2 max L

M B R L ฀

slide-44
SLIDE 44

Eddy current coupling

European School on Magnetism,September 8-18th, Cluj Napoca

Tahometer

2 2 max

/

L

M R B ρ ฀

slide-45
SLIDE 45

Hysterezis couplings

European School on Magnetism,September 8-18th, Cluj Napoca

~

hyst

M pV

HdB

∫

slide-46
SLIDE 46

Loudspeaker

European School on Magnetism,September 8-18th, Cluj Napoca

1 1 ( ) 2

g m m m

W B H V γσ =

slide-47
SLIDE 47

Voice coil motors

European School on Magnetism,September 8-18th, Cluj Napoca

slide-48
SLIDE 48

Voice coil motors

European School on Magnetism,September 8-18th, Cluj Napoca

slide-49
SLIDE 49

Motors with Nonferrous rotors

European School on Magnetism,September 8-18th, Cluj Napoca

π SEA/France ICPE-1980

slide-50
SLIDE 50

Watches

European School on Magnetism,September 8-18th, Cluj Napoca

slide-51
SLIDE 51

Magnetic separators

European School on Magnetism,September 8-18th, Cluj Napoca

slide-52
SLIDE 52

Actuators with PM

European School on Magnetism,September 8-18th, Cluj Napoca

slide-53
SLIDE 53

High speed motors

European School on Magnetism,September 8-18th, Cluj Napoca

  • G. W. Jewell, 2002, UK
slide-54
SLIDE 54

PM motors

European School on Magnetism,September 8-18th, Cluj Napoca

Double Stator Motor Stepper Motor Flux Directions Radial Axial

slide-55
SLIDE 55

250 kW Generator

European School on Magnetism,September 8-18th, Cluj Napoca

  • G. W. Jewell, 2002, UK
slide-56
SLIDE 56

Very high temperature motors

European School on Magnetism,September 8-18th, Cluj Napoca

slide-57
SLIDE 57

Micromagnets

European School on Magnetism,September 8-18th, Cluj Napoca

PM for e.m. watch

ICPE-1982

slide-58
SLIDE 58

Magnetic orientation

European School on Magnetism,September 8-18th, Cluj Napoca

Magnetotactic bacteria Magnetic navy compass

slide-59
SLIDE 59

Measuring Equipement

European School on Magnetism,September 8-18th, Cluj Napoca

slide-60
SLIDE 60

Magnetic recording

European School on Magnetism,September 8-18th, Cluj Napoca

slide-61
SLIDE 61

Medical Applications

European School on Magnetism,September 8-18th, Cluj Napoca

slide-62
SLIDE 62

Many thanks to

European School on Magnetism,September 8-18th, Cluj Napoca

Mihai Mihaescu Mirela Codescu Mircea Ignat Eros Patroi Iulian Iordache

slide-63
SLIDE 63

European School on Magnetism,September 8-18th, Cluj Napoca

slide-64
SLIDE 64

European School on Magnetism,September 8-18th, Cluj Napoca

slide-65
SLIDE 65

European School on Magnetism,September 8-18th, Cluj Napoca