Minimum Energy Performance Standards and Mandatory Efficiency Requirements for Electric Motors.

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Minimum Energy Performance Standards and
Mandatory Efficiency Requirements for Electric
Motors.

• Frank Cerra
• Australian Electrical and Electronics
  Manufacturers Association Chair of Rotating
  Machines Forum
• Engineering Manager, SEW-Eurodrive, Australia

SIRF Electrical Maintenance Safety National
Forum September 2007
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Australia actively regulates energy efficiency

• Adopts worlds best practice in efficiency
  standards and regulation
• Is committed to the reduction in emissions of
  greenhouse gasses
• Is committed to improving the energy efficiency
  of electrical equipment
• through Australian Greenhouse Office (AGO)
  programs
• minimum energy efficiency levels of domestic and
  industrial products are regulated
• Has mandatory Minimum Energy Performance
  Standards for three phase electric motors

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Why Motors ?

• Easy to identify and regulate for efficiency
• 2-5 improvement potential per motor
• Small increment, but many motors
• Motor driven applications comprise 48 of total
  industrial energy use 25 of total commercial
  energy use
• Regulatory Impact Statement for Minimum Energy
  Performance Standards for Electric Motors.
  Prepared by Syneca Consulting. Published December
  2003. http//www.energyrating.gov.au/library/pubs/
  200311-rismotors.pdf

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MEPS (Minimum Energy Performance Standards)

• Is regulated through State Government laws and
  regulations
• Motors that fall below efficiency levels
  documented in the Australian Standard AS1359.5
  are excluded from the market
• Is mandatory for suppliers
• Motors must be registered www.energyrating.gov.
  au
• Compliance by regulators and Australian
  Greenhouse Office with random check testing of
  motors at NATA accredited labs

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MEPS1

• Came into effect October 2001
• MEPS1 minimum levels match European EFF2
  efficiency levels for 2 and 4 pole motors
• High Efficiency levels match European EFF1 for 2
  and 4 pole motors
• But MEPS1 extended further to also cover 6 and 8
  pole motors
• Covered the power range 0.73 up to 185kW

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The effect of MEPS1 on motor industry and motor
usage

• MEPS 1 was a successful and straight forward
  program for industry
• Motors were already available that met the
  minimum (EFF2) levels
• Australia is a net importer of motors
• As a result of Eurpoean CEMEP US EPACT
  suppliers already had motor designs available to
  the market
• Benchmarking shows the success of the program
• a study of motor efficiency levels in 5 Asian
  economies in 2005
• Peter du Pont, Jesper Vauvert, Benchmarking of
  Electric Motor Efficiency Levels in Five Asian
  Economies. Conference Proceedings EEMODS 2005
• this study concluded Australia had the highest
  average motor efficiency of the 5 economies

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MEPS1 ? MEPS2

• Success of MEPS1 drove a rapid move to MEPS2
• Regulatory Impact Statement commissioned in 2003
  to identify the next MEPS stage
• AS1359.5 was updated in 2004
• MEPS2 came into effect in April 2006
• MEPS2 was again based on world best practice
• The ambitious targets of MEPS2 required more
  involvement of motor manufacturers for the
  success of the program

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MEPS2 - Risk Impact Statement 2003 identified

• Motors account for 48.75 of industrial energy
  use 25 commercial energy use
• Greenhouse emissions attributable to energy used
  by electric motors 9.4 to 14
• MEPS2 would reduce greenhouse emissions by 8900
  GWH and 7.7MTon CO2
• Motor losses would need to be reduced 10 to 20
  to achieve the above
• 70 of motors on the market at that time would
  not meet the proposed MEPS2 levels and would be
  excluded from the market

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The changes introduced by MEPS2 into AS1359.52004

• EFF2 dropped from April 2006
• EFF1 became MEPS from April 2006
• A new High Efficiency level was defined based on
  15 additional reduction of losses.

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MEPS 2 What does it mean ?

• Motors imported into Australia
• after 1 April 2006
• must meet new Minimum Energy Performance
  Standards
• to the levels set out in Australian Standard
  AS1359.52004
• Tables A2 B2, A3 B3
• This affects
• 2, 4, 6 and 8 pole motors
• in the power range 0.75 to 185kW

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Standards and legislative requirements
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Standards and legislative requirements
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Australian Standard AS/NZS1359.52004

• Applies to three phase cage induction motors in
  2, 4, 6 and 8 pole design
• In the power range 0.75 up to 185kW
• Stipulates minimum motor efficiency levels to two
  internationally recognized test methods
• Identifies changeover dates
• Current MEPS Tables A2 or B2
• Premium/High Efficiency Tables A3 or B3

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Why Two Efficiency Test Methods ?

• Both internationally recognised and used
• Test Method A (AS1359.102.3)
• involves direct measurement of stray load losses
• Based on IEEE112B IEC61972 US method
• is equivalent to the new IEC60034-2-1
• is more accurate and is expected to be adopted as
  preferred method in future
• Test Method B (AS1359.102.1)
• assumes a fixed 0.5 for stray load losses
• Based on the old IEC34-2 Old European method

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Two Test Methods

• Efficiency in the test methods are different!
• The test methods treat stray load losses
  differently.
• eg. 4kW, same motor tested under different
  methods
• Method A MEPS2006 87.0
• Method B MEPS2006 88.3
• At the next revision of the AS1359.5 standard it
  is likely that Method A, which is technically
  equivalent to IEC60034-2-1, will be the preferred
  test method

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Effect of Efficiency Improvement on Motor Design
and Selection
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What makes up efficiency losses?
Bearings Fan
Friction losses
Pulsation losses in teeth and yoke Surface losses
in stator an rotor Losses due to transverse
currents between rotor-bars Losses in stator
winding due to currents of non line
frequency Losses in stator winding due to eddy
currents Losses in end areas of winding ...
Additional losses
Alternating magnetization of core sheets Eddy
current losses
Iron losses
I²R losses in rotor-cage
I²R losses in stator winding
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Efficiency improvement by Motor loss reduction
Stator slot design, more copper in stator slots
and winding geometry changes to reduce stator
resistance losses
Increase in active material, slot design
optimization, improved quality of lamination
steels and thinner laminations to reduce iron
losses
Increase in size of conductor bars, slot design
and end rings, possible use of copper instead of
aluminium to reduce rotor resistance losses
Improved fan design, sealing and low friction
bearings to reduce friction losses
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Losses in induction motors
Relative Distribution of Losses in Asynchronous
Motors Note small motors have higher I2R stator
losses ? loss reduction means more slot area ?
larger motors
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What happens to the motor ?

• Efficiency ?
• Increase in active material size increase

• Torque/speed characteristic curves become flatter
  and flatter from standard to premium, with less
  pronounced pull-up and pull-out torques.

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What happens to the motor ?

• Starting to Nominal Current ratio ?
• Starting torque ?
• Slip at rated power ?, Rated Speed ?
• Power factor ?
• Thermal utilization ?
• Rotor Inertia ?
• Weight ?
• Price ?

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High and Premium Efficiency Motors
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• Application Considerations
• and
• Total Drive System
• Efficiency

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Lifecycle cost of motor

• Over a motor lifecycle the costs of running the
  motor can far exceed the initial purchase costs
  especially in applications where the motor is
  running continuously
• When buying a motor consider
• Application
• Operating time and duty cycle
• Efficiency
• Motor size
• Transmission losses
• Rewind/Repair
• Variable speed Operation

Source EUP Lot 11 Motors, Report No. 3, Analysis
of existing technical and market information,
ISR- University of Coimbra, Aníbal T. de Almeida
et al, April 2007
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Average Induction Motor Life (including repairs)
Power range Average life years
1.0 7.5 kW 12
7.5 75 kW 15
75 250 kW 20
Source EUP Lot 11 Motors, Report No. 3, Analysis
of existing technical and market information,
ISR- University of Coimbra, Aníbal T. de Almeida
et al, April 2007
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Motor Application

• Highest efficiency motors are most suited
  where
• Many hours of operation daily
• Majority of operation at high load (75 )
• Few start/stop and braking operations
• Combination with transmission elements that also
  have a high degree of efficiency
• Applications where Highest efficiency motors
  are less suited due to their higher cost, rotor
  inertia, weight,
• Low utilization applications
• Start - stop (S3 duty) applications
• Applications with weight and/or space
  restrictions

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The drive train effect on system efficiency
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Look at the whole drive train !!!
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Efficiencies of Transmission Elements
Transmission elements Conditions Efficiency
Wire rope per complete contact of the rope around the drum (sleeve or anti-friction bearings) 0.91 0.95
V belts per complete contact of the belt around the V-belt pulley (normal belt tension) 0.88 0.93
Polymer belts per complete contact/rollers have anti-friction bearings (normal belt tension) 0.81 0.85
Rubber belts per complete contact/rollers have anti-friction bearings (normal belt tension) 0.81 0.85
Toothed belt per complete contact/rollers have anti-friction bearings (normal belt tension) 0.90 0.96
Chains per complete contact/rollers have anti-friction bearings (dependent on chain size) 0.90 0.96
Gear units helical gears oil-lubricated, 3 stages dependent on gear quality and lubrication type 0.94 0.97
Gear units Worm gears Oil lubricated single stage Oil Lubricated first stage helical, second stage worm dependent on worm gear ratio, quality lubrication type 0.4 - 0.7 0.5 - 0.9
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Look at the system
Source Motor Challenge - Energy Efficient Motor
Driven Systems, European Copper Institute, April
2004
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Efficiency Gains / Energy Cost Reduction-

• Take the whole system approach.
• It can result in
• much higher
• efficiency gains
• and
• cost savings

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Future Directions in Motor Efficiency
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Future Directions International Standards

• IEC 60034-2-1 Ed.1 Rotating electrical machines
  - Part 2-1 Standard methods for determining
  losses and efficiency from tests (excluding
  machines for traction vehicles)
• Voted on and final draft was accepted July 2007
• Harmonizes the motor efficiency test methods to
  one set of methods globally that deliver low
  uncertainty in measurement

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IEC60034-2-1
Low uncertainty by direct measurement of losses
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IEC60034-30 (draft !)

• IEC 60034-30 Ed.1 Rotating electrical machines -
  Part 30 Efficiency classes of single-speed
  three-phase cage induction motors
• Intended to harmonize motor efficiency levels
  globally

• Efficiencies will be based on test methods of
  IEC60034-2-1

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Future Efficiency Classes
IEC60034-30 Europe (50Hz) US (60Hz) AU - AS1359.5
IE1 Standard Efficiency Comparable to EFF2 Comparable with South American Standards Comparable with table B1 MEPS1 levels - No longer allowed
IE2 High Efficiency Comparable to EFF1 Identical to NEMA Energy Efficiency / EPACT MEPS2 level Comparable with table A2
IE3 Premium Efficiency Extrapolated from IE2 with 10 to 15 lower losses Identical to NEMA Premium Efficiency Comparable with table A3
IE4 Super Premium Eff Extrapolated from IE3 with 10 lower losses
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IEC60034-30 proposed efficiency classes
0.75kW to 370kW
Super Premium efficiency
Premium efficiency
Standard efficiency
High efficiency
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The Global Move to Higher Efficiency Motors
Source seeem.org
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AEEMARotating Machines Forum
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AEEMA Rotating Machines Forum

• Motor and drives suppliers formed a
  representative committee to highlight the real
  world impact of MEPS
• The intention of the forum is to be involved to
  ensure MEPS2 is successful and have a good
  working relationship with the AGO, but also to
  address issues that motor and drive
  manufacturers, suppliers and users face
• Manufacturers and Suppliers are the principal
  stakeholders that face the motor end users and
  OEMs directly
• are best placed to inform motor users, and also
  provide constructive feedback and criticism to
  the AGO and regulators.

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AEEMA RMF E3 Education Campaign
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Frequently asked questions
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• Thank you
• Further information
• AEEMA - Rotating Machines Forum
• www.aeema.asn.au
• Energy rating website
• www.energyrating.gov.au/emmenu.html
• frank.cerra_at_sew-eurodrive.com.au