Energy Efficiency of Induction MachinesEfficiency of ...Improvement of Induction MotorImprovement of...

Leibniz Universität Hannover Institute for Drive Systems and Power Electronics

Yokogawa Power Meter Seminar

Energy Efficiency of Induction Machines –Energy Efficiency of Induction Machines –Normative Requirements, Technical Potential, Comparison with Other Types of Electrical Machinesof Electrical Machines

Dr -Ing J Steinbrink /Dr. Ing. J. Steinbrink /Prof. Dr.-Ing. Bernd PonickLeibniz Universität HannoverInstitute for Drive SystemsInstitute for Drive Systems and Power ElectronicsWelfengarten 1D-30167 Hannover

19th of November, 2013 / Steinbrink - Ponick1 Yokogawa Power Meter Seminar 2013 HanoverYokogawa Power Meter Seminar 2013 Hanover 19th of November, 2013 / Steinbrink - Ponick

Germanyhttp://www.ial.uni-hannover.de


Energy Efficiency of Induction Machines

Overviewten

ts

OverviewIntroduction

Con

t

Normative Requirements

Technical Potential

Comparison with Other Types of Electrical Machines

Conclusion



Challenges for Standard Induction Motors

Increasing legislative

ctio

n

requirements on energyefficiency

Increasing demand forIntr

odu

c

reel

.it

Increasing demand for outstanding torque or power density in some applications

rom

: w

ww

.

“New” motor technologies:

• PM synchronous motors

F

• Synchronous reluctance motors

• Switched reluctance motors

• Flux switching synchronous motors

Will i d ti t


Will cage induction motors have a future?


International Standardization of Efficiency Classes in 2009Efficiency Classes in 2009

IEC 60034-30 defines efficiencyclasses IE1 IE3 but only form

ents

classes IE1 ... IE3 – but only forline-fed cage induction motorswith

Req

uir

em

UN < 1000 V0,75 kW < PN < 375 kWf = 50 Hz or 60 Hzm

ativ

e R

fN = 50 Hz or 60 Hz2, 4 or 6 polesno pole change

de A

lmei

daNor

S1 or S3 operationnormal conditionsline start -U

C, P

rof.

d

line start, ...60 Hz limits identical to DOE-EPACT or NEMA Premium Fr

om:

ISR-


50 Hz limits based on CEMEP: EFF2 → IE1, EFF1 → IE2 IE limits for 4pole motors


EuP Legislation for the EU based on IEC 60034-30 (2009)based on IEC 60034 30 (2009)EU directive 640/2009:

IE2 mandatory from 2011-06-05

men

ts

yIE3 or IE2 with converter supply for PN > 7,5 kW mandatory from 2015-01-01IE3 or IE2 with converter supply for PN > 0,75 kW mandatory from 2017-01-01

Req

uir

em

Different reactions on the motor market: ‘Work arounds‘: Misleading labeling, e. g. S9 instead of S1Demand of IE4 motors even though IE4 hasn‘t been standardized yetm

ativ

e R

Demand of IE4 motors, even though IE4 hasn t been standardized yetDemand of motors outside scope, but with IE classification

Prior to further legislation steps, normative basis must be developed:

Nor

Prior to further legislation steps, normative basis must be developed:EU mandate M/470 EN for motorsEU mandate M/476 EN for converters and power drive systems



Consequence of EU Mandates

New IEC 60034-30-1 with extended scope for single speed motors:

men

ts

Rated power down to 120 W and up to 1000 kWRated voltage down to 50 V and up to 1000 V

Req

uir

em

2, 4, 6 or 8 polesDesigned for sinusoidal supply

mat

ive

R

Efficiency classes are independent from motor technologyNew IEC 60034-30-2 for variable speed motors maximum speed between 100 rpm and 10 000 rpm (independent of no of poles)

Nor

between 100 rpm and 10.000 rpm (independent of no. of poles) is currently being drafted

⇒ Legislation on minimum efficiency classes for variable speed motorscannot be released before 2016



Options for Improvement of Induction Motor Efficiencyof Induction Motor Efficiency

a) Technology:

enti

al

Improved slot fill factor in stator;

f

ical

Pot

e

rotor cage from casted copper

b) Material:

Tech

n

b) Material:

Improved lamination

) D i de A

lmei

da

c) Design:

Reduction of stray load losses -U

C, P

rof.

d

load losses

But: Restriction due to limited starting From

: IS

R-


gcurrent for single speed motors!


Example 1: Design Alternatives for EfficiencyImprovement of Induction MotorImprovement of Induction Motor

1,5 kW, 3000 rpm single speed cage induction motor

enti

alic

al P

ote poles f / Hz l / mm cos ϕ η / %

Original design 2 50 90 0,82 81,1

Increased core length 135 0 89 81 5

Tech

n Increased core length 135 0,89 81,5

Improved core material (M330-50A) 135 0,87 84,4

Copper for rotor cage 135 0,87 85,9

1,5 kW, 3000 rpm motor with converter supply

pp g , ,

poles f / Hz l / mm cos ϕ η / %

Original design 2 50 90 0,82 81,1

4 poles, reduced core length 4 100 75 0,82 85,0

Improved core material (M330-50A) 75 0,81 85,6

Original core length 90 0,77 86,3

Copper for rotor cage 90 0 77 86 9


Copper for rotor cage 90 0,77 86,9

Slightly increased core length 100 0,82 87,4


Example 2: Influence of Lamination Material on Maximum Torque and Efficiencyon Maximum Torque and Efficiency

enti

al

FeCo50

ical

Pot

eTe

chn

M330-35A



Example 2: Influence of Lamination Materialon Maximum Torque and Efficiencyon Maximum Torque and Efficiency

55 kW, 4 pole cage induction motor

enti

alic

al P

ote

M330 35A F C 50

Tech

n M330-35A FeCo50

Efficiency maps in the torque in Nm vs. speed in rpm plane

High end material reduces magnetizing current by 25%

With optimization of geometry high end material increases maximum


With optimization of geometry, high end material increases maximum torque by 20% AND efficiency by 1% for identical stator current


Alternatives to Induction Machines:Synchronous Reluctance MachinesSynchronous Reluctance Machines

hin

ess

of M

ach

her

Typ

esw

ith

Oth

mpa

riso

n

“Classical” Line Start Synchronous Reluctance Motors

Com



Alternatives to Induction Machines:Synchronous Reluctance MachinesSynchronous Reluctance Machines

hin

ess

of M

ach

abb.

de

her

Typ

es

rom

: w

ww

.a

wit

h O

th Fr

mpa

riso

n

“New” Converter-fed Synchronous Reluctance Motors

Com



Alternatives to Induction Machines:Promise of Synchronous Reluctance MachinesPromise of Synchronous Reluctance Machines

hin

es No rotor losses

s of

Mac

h

Improved efficiency

her

Typ

es Higher torque density

wit

h O

thm

pari

son

C

om



Current Locus of Induction Machine h

ines Re Stator resistance neglected

σ = 8%

s of

Mac

h σ 8%

her

Typ

es

1NIkippM∼

wit

h O

th

Im 11( 0) Us

jXI = = 1

1( ) Usj X

I → ∞ =

mpa

riso

n

11( )

jX 1j Xσ

Com



Current Locus of Synchronous Reluctance Machineh

ines Re Stator resistance neglected

s of

Mac

hh

er T

ypes

1NI kippM∼

wit

h O

th

Im 11( 0 ) UI δ = ° = 1

1( 90 ) UX

I δ = ° =

mpa

riso

n 1( 0 )

djXδ 1( )

qjX

Com

max

1cos

1

q

d

q

XXXϕ

−=

+


1dX

+


Current Locus of Simple Line-Start Synchronous Reluctance Machine (Xd/Xq=2)Reluctance Machine (Xd/Xq 2)

hin

es Re

s of

Mac

hh

er T

ypes

1UII

wit

h O

th

Im1( 0 ) UI δ °

11( 90 )

q

UjX

I δ = ° =1NI

mpa

riso

n 1

1( 0 )d

UjX

I δ = ° =

Com

max

11 12cos 0,33111

q

d

q

XXXϕ

− −= = =

++


11 2dX

++


Current Locus of Variable Speed Synchronous Reluctance Machine (Xd/Xq=5)Reluctance Machine (Xd/Xq 5)

hin

es Re

s of

Mac

hh

er T

ypes

U1NI

wit

h O

th

Im

11( 90 )

q

UjX

I δ = ° =kippM∼

mpa

riso

n

11( 0 )

d

UjX

I δ = ° =

Com

d

max

11 15cos 0,67111

q

d

q

XXXϕ

− −= = =

++


11 5dX

++


Challenges for Synchronous Reluctance Machines

Thickness of rotor leakage paths s mechanical ob stnessh

ines

vs. mechanical robustness

Permeability of rotor core vs permeability of stator cores

of M

ach

vs. permeability of stator core

Influence of manufacturing on permeability of rotor leakage paths

her

Typ

es

g

Negative influence of stator saturation on Xdand thus on cos ϕ

wit

h O

th

High torque oscillations during asynchronous starting

mpa

riso

n

Com



Conclusion

Standardization and legislation on efficiency classes won‘t care aboutmotor technology in the futureu

sion

motor technology in the future

For single speed motors, induction motors remain – besides line startPM synchronous motors for small ratings – the only option

Con

clu

sy c o ous o o s o s a a gs e o y op o

In many variable speed applications, induction motors can easily reachIE4

High end lamination material will significantly improve torque densityand efficiency

Converter-fed synchronous reluctance motors are – contrary to switched reluctance motors – an alternative toreluctance motors an alternative to induction machines for variable speed applications, but not their grave-digger


grave-digger

Energy Efficiency of Induction MachinesEfficiency of ...Improvement of Induction MotorImprovement of...

Documents

Transcript of Energy Efficiency of Induction MachinesEfficiency of ...Improvement of Induction MotorImprovement of...