영구자석동기선형전동기의추력맥동저감을위한극수/슬롯조합및치형배치설계

한국전기연구원정시욱

Pole/slot combination and teeth arrangement design for thrust ripple reduction of permanent magnet linear synchronous motor

2/16

Research Background• PMLSM pros & cons

• Speed vs. thrust

• Thrust ripple due to end-effect

Comparative

Study(4p/3s)• Conventional design

vs. Proposed design

• Detent force

• Speed ripple

Comparative

Study(5p/6s)

• Pole/slot combination & winding distribution

• Conventional design vs. Proposed design

Conclusion

3/16

Conventional PMLSM(Single-sided)

• High speed & acceleration• No backlash & high precision• Maintenance free• Low noise/vibration• Unlimited traveling length

Pros Cons

Mover(Iron)

Stator(Iron)

Auxiliary teeth design(Yaskawa)

• Rare earth PM cost

• Huge magnetic attraction• Thrust ripple due to end-effect

End-effect

4/16

Time

Sp

eed

tdtcta

tm

T

Fd

Fl

Fa

Th

rust

Vc

Thrust ripple

Speed ripple

Low speed

Constant speed

Low frictional coefficient

Fx = m ሷx +Fl

Fl = c ሶx + μ(Fy+mg) + Fseal friction

5/16

0 3 6 9 12 15 18 21 24 27-90

-60

-30

0

30

60

90

Section1

Section1+Section3

Section3

Det

ent

forc

e[N

]

Displacement[mm]

0.0 4.5 9.0 13.5-40

-30

-20

-10

0

10

20

30

40

Det

ent

forc

e[N

]

Displacement[mm]

Sum Section1+Section3 Section2

U V W U V W U V W U V W U V W

Wt

Wpp

Hp g

p 72

3

46.2

Symmetry lineConventional 4pole-3slot based PMLSM

U V W /V /W /U W U V/V /W /U /V /W /U

p p 72

3

46

.2

Section1 Section2 Section3

Symmetry line

Proposed 4pole-3slot based PMLSM

“Double-Sided Iron-Core PMLSM Mover Teeth Arrangement Design for Reduction of Detent Force and Speed Ripple”IEEE Transactions on Industrial Electronics ( Volume: 63, Issue: 5, May 2016 )

6/16

0.0 4.5 9.0 13.5 18.0 22.5 27.0-60

-40

-20

0

20

40

60 Without skewing With skewing

Det

ent

forc

e[N

]

Displacement[mm]

0.0 4.5 9.0 13.5 18.0 22.5 27.0-60

-40

-20

0

20

40

60 Without skewing With skewing

Det

ent

forc

e[N

]

Displacement[mm]

Conventional 4pole-3slot based PMLSM Proposed 4pole-3slot based PMLSM

0.0 4.5 9.0 13.5 18.0 22.5 27.0-12

-9

-6

-3

0

3

6

9

12

Det

ent

forc

e[N

]

Displacement[mm]

Conventional design

Proposed design

0.00 6.75 13.50 20.25 27.00 33.75-12

-9

-6

-3

0

3

6

9

12

Conventional design

Proposed design

Det

ent

forc

e[N

]

Displacement[mm]

Conventional vs. Proposed(FEA) Conventional vs. Proposed(Test)

• Conventional design: 6.4N, Proposed design: 1.7N

• Peak detent force reduction: 73%

7/16

0.0 0.4 0.8 1.2 1.6 2.0 2.4

0

20

40

60

80

100

120

Vel

oci

ty[m

m/s

]

Time[sec]

Ripple: 2.06%

0.8 1.0 1.2 1.4 1.698

99

100

101

102

Vel

oci

ty[m

m/s

]

Time[sec]

0.0 0.4 0.8 1.2 1.6 2.0 2.4

0

20

40

60

80

100

120

Ripple: 1.32%

Vel

oci

ty[m

m/s

]

Time[sec]

0.8 1.0 1.2 1.4 1.698

99

100

101

102

Vel

oci

ty[m

m/s

]

Time[sec]

Conventional 4pole-3slot based PMLSM Proposed 4pole-3slot based PMLSM

• Conventional design: 2.06%, Proposed design: 1.32%

• Speed ripple reduction at 100mm/s: 36%

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LmoverLmover Lmover Lmover

Mover1 Mover2

Stator

Pole/slot Mover1 Mover2

5/6 U, /U, /V, V, W, /W /U, U, V, /V, /W, W

7/6 U, /U, /V, V, W, /W /U, U, V, /V, /W, W

7/9U, V, W, /W, /U, /V, V,

W, U/U, /V, /W, W, U, V, /V,

/W, /U

8/9U, /U, U, V, /V, V, W,

/W, WU, /U, U, V, /V, V, W,

/W, W

10/9U, /U, U, V, /V, V, W,

/W, WU, /U, U, V, /V, V, W,

/W, W

11/12U, /U, U, /U, /V, V, /V,

V, W, /W, W, /W/U, U, /U, U, V, /V, V,

/V, /W, W, /W, W

13/12U, /U, U, /U, /V, V, /V,

V, W, /W, W, /W/U, U, /U, U, V, /V, V,

/V, /W, W, /W, W

=pn, p: pole-pitch, n: number of phase

Conventional winding distribution Proposed winding distribution

Mover1 Mover2

Stator

Pole/slot Mover1 Mover2

5/6 U, /U, /V, V, W, /W W, /W, /U, U, V, /V

7/6 U, /U, /V, V, W, /W V, /V, /W, W, U, /U

7/9U, V, W, /W, /U, /V, V,

W, UW, U, V, /V, /W, /U, U,

V, W

8/9U, /U, U, V, /V, V, W,

/W, W/W, W, /W, /U, U, /U,

/V, V, /V

10/9U, /U, U, V, /V, V, W,

/W, W/V, V, /V, /W, W, /W,

/U, U, /U

11/12U, /U, U, /U, /V, V, /V,

V, W, /W, W, /WW, /W, W, /W, /U, U,

/U, U, V, /V, V, /V

13/12U, /U, U, /U, /V, V, /V,

V, W, /W, W, /WV, /V, V, /V, /W, W, /W, W, U, /U, U, /U

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Conventional 5p6s based PMLSM

Proposed 5p6s based PMLSM

10/16

Conventional winding distribution Proposed winding distribution

100%Load

R-sq: 99.95%

300%Load

R-sq: 99.83%

DetentForce

R-sq: 97.22%

100%Load

R-sq: 99.93%

300%Load

R-sq: 99.83%

DetentForce

R-sq: 99.85%

11/16

Conventional winding distribution Proposed winding distribution

100%Load

R-sq: 99.95%

300%Load

R-sq: 99.83%

DetentForce

R-sq: 97.22%

100%Load

R-sq: 99.93%

300%Load

R-sq: 99.83%

DetentForce

R-sq: 99.85%

12/16

Pk. 6.51N

Pk. 2.24N

• Peak detent force reduction: 65.6%

13/16

FEA vs. Measurement (Proposed design)

Static thrust (V-U DC excitation, 2.0A) Static thrust (3-phase excitation)

Back EMF @1.0m/s Back EMF @1.0m/s

14/16

Speed ripple @10mm/s: 1.95%

Measurement (Proposed design)

0 1 0 2 0 3 0 4 0 5 0 6 0

5

4 . 5

4

3 . 5

3

2 . 5

2

1 . 5

1

0 . 5

0

- 0 . 5

Dis

tan

ce (

mic

ron

s)

T i m e ( s e c o n d s )

D I S T A N C E v s T I M E P L O T

D i s t a n c e a g a i n s t t i m e - L i n e a r기 계 명 : 일 련 번 호 : 일 자 : 2 0 1 7 - 1 0 - 2 5 1 1 : 2 9 : 5

측 정 축 : 측 정 위 치 : F i l e n a m e : 1 u m _ r e s o l u t i o nC a p t u r e r a t e : 1 0 0 0 0 H z

M a x v a l u e : 5 . 0 7 4 3 7 1a t t i m e : 2 5 . 6 8 3 2M i n v a l u e : - 0 . 5 6 8 0 9 8a t t i m e : 5 5 . 3 1 7 5

0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0

4 0

3 5

3 0

2 5

2 0

1 5

1 0

5

0

에러

량 (

micro

metr

es)

타 겟 ( m i l l i m e t r e s )

A c c u r a c y a n d R e p e a t a b i l i t y

I S O 2 3 0 - 2 1 9 9 7 A n a l y s i s P l o t - 직 선기 계 명 : 일 련 번 호 : 일 자 : 2 0 1 7 - 1 0 - 2 5 1 1 : 5 0 : 1측 정 축 :

M e a n D e v . M : 4 2 . 0 5 0S y s . D e v . E : 4 2 . 1 6 0R e p e a t . R + : 1 . 0 0 4R e p e a t . R - : 1 . 2 8 4

R e v e r s a l B : 0 . 6 6 0A c c u r a c y A + : 4 2 . 5 7 1A c c u r a c y A - : 4 2 . 6 4 9A c c u r a c y A : 4 2 . 8 8 5

Repeatability: ± 0.642㎛Resolution: 1㎛

Laser interferometer

15/16

Advantages in general Possibly the simplest end-effect reduction technique Peak detent force reduction for 5p6s basd PMLSM: About 65.6% Negligible sacrifice in thrust/mover volume Patent pending: Korea, PCT

Experimentation Altair Flux simulation shows a good agreement.

16/16

Senior Researcher/IEEE Senior MemberElectric Motor Research Center

Korea Electrotechnology Research Institute

Shi-Uk ChungE-mail : suchung@keri.re.kr

Tel : +82-55-280-1452