This document summarizes information about super-premium electric motors. It defines super-premium motors as having at least 15% lower losses than IE3 premium efficiency motors. It discusses various technologies that can enable higher motor efficiencies, including copper rotors, line start permanent magnet motors, switched reluctance motors, synchronous reluctance motors, and permanent magnet motors. The document also presents data on expected motor market trends and total lifetime costs, finding that super-premium motors can provide significant energy savings over their operational lifetime.

1. SUPER-PREMIUM ELECTRIC MOTORS
Motors Academy - Webinar Course
Anibal T. de Almeida
ISR-University of Coimbra, Portugal
21st November 2017
1

2. What is a Super-Premium Motor?
• IE3 have at least 15% lower losses than IE2 motors
• A Super-Premium IE4 Class has at least a 15% loss
difference in relation to IE3 / Premium.
• A Ultra-Premium (new IE5 Class) has at least a 15% loss
difference in relation to IE4 / Super- Premium.
2

3. IM Efficiency Classification
IEC 60034-30-1 (2014)
Ultra / Super-Premium
3

4. Names of Efficiency Classes Around the World
4

5. Economics and Markets in Europe
Total motor-sales in the EU-27 (0,75 to 375 kW) Source: CEMEP
5

6. 6
Worldwide MEPS timeline
* 7,5-375 kW - IE3 efficiency level or IE2 + VSD
** 0,75-375 kW - IE3 efficiency level or IE2 + VSD
Source:ISR-University of Coimbra

7. Expected Evolution of the European LV Motor
Market (units; line-fed)
7
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
2012 ... 2020
IE4
IE3
IE2
IE1

8. Expected European shares of Line-Fed and Converter
Fed Motors
8

9. Technologies for Higher Efficiency Motors
9
IE4 IE5
PM Motor
+
VSD
IE3
Squirrel Cage
Induction
Motors
LSPM
SynRel Motor
+
VSD
PM Motor
+
VSD
Premium Super-Premium Ultra-Premium
SynRel / PM Motor
+
VSD
IE6?
PM Motor +VSD
Source:ISR-University of Coimbra

10. High Efficiency Motor Solutions
10

11. Commercial available
Ultra and SuperPremium Motors
11

12. Motor Losses
• The electrical losses (also called Joule losses) are expressed by I2R, and
consequently increase rapidly with the motor load. Electrical losses appear
as heat generated by electric resistance to current flowing in the stator
windings and in the rotor conductor bars and end rings.
• Magnetic losses occur in the steel laminations of the stator and rotor. They
are due to hysteresis and eddy currents, increasing approximately with the
square of the magnetic flux-density.
• Mechanical losses are due to friction in the bearings, ventilation and
windage losses.
• Stray load losses are due to leakage flux, harmonics of the air gap flux
density, non-uniform and inter-bar currents distribution, mechanical
imperfections in the air gap, and irregularities in the air gap flux density.
12

13. Typical fraction of losses
in 50-Hz, four-pole IMs
Motor Losses Vs. Motor Power
13

14. 14
Induction Motor Losses

15. Friction Losses and Windage Losses
Core Losses
Stray Load
Losses
Joule Effect
Losses (I2R)
Motor Losses
Vs. Motor Load
15

16. More copper in the stator
(larger diameter wire and
smaller coil heads)
Reduced friction
bearings
Efficient Fan design /
improved cooling
Larger conductive rotor bars and
end-rings or conductors of lower
resistivity (Copper)
Longer stator with more and
improved magnetic steel; thinner
laminations
Improving Induction Motor Efficiency
16

17. • A copper rotor is a rotor made of electrical steel (laminations) where
the slots and end rings are filled with copper instead of the traditional
material (aluminium).
• The use of copper in place of aluminium can lead to improvements in
motor energy efficiency due to a significant reduction in I2R losses in the
rotor.
17
Induction motors – die casting copper rotor

18. 18
• EXAMPLE: 1.1-kW DIE CASTING COPPER ROTOR
Higher efficiency
and lower rotor
inertia, when
compared to the
aluminum rotor
EEMs.
COMPARISON
BETWEEN COPPER
(MI_C) AND
ALUMINUM (MI_A)
CAGE MOTORS
Squirrel Cage Aluminum Copper
Efficiency Class IE2 IE3
Enclosure TEFC TEFC
Nominal Voltage, Un 400 V 400 V
Nominal Frequency, fn 2.80 A 2.45 A
Nominal Speed, nn 50 Hz 50 Hz
Nominal Power, Pn 1.1 kW 1.1 kW
Power Factor cosφn 0.77 0.78
Induction motors – die casting copper rotor

19. Energy Efficient Indution motors
Die casting copper rotor vs. aluminum rotor (4 pole, 1.1 kw)
19
EFFICIENCY
POWER FACTOR
Source:ISR-University of Coimbra

20. History of Permanent Magnets
20

21. 21
Rare Earth Magnet Disadvantages
• High cost
• Price instability / uncertainty due to concentrated
production (> 70% is in China).
• Limited supply of Dysprosium.
• Environmental impact of extraction / processing.
Baotou, China

22. Line Start PM motors (LSPM)
•Hybrid motor with squirrel cage rotor fitted with high
energy permanent magnets (NeFeB*) making it suitable
for direct on line start
• Interchangeable with induction motors (same output x
frame ratio)
22

23. 23
LSPM Rotor Structure
Aluminium
cage
Flux barrier
Permanent
magnet
• Hybrid motor: induction + permanent magnet +
reluctance
Source: WEG
Example picture, not actual geometry

24. 24
Advantages of LSPM
• Synchronous operation  no I²R losses in the aluminum
cage.
• Higher efficiency compared to Premium Efficiency
induction motors  high energy savings.
• Low bearing temperature  longer life and less
maintenance.
• No sensors  high reliability.
• Interchangeability with existing installations.
• No need for special protection relays.
• High cost
• Torque behaviour

25. Line Start PM motors (LSPM)
25
EFFICIENCY - 4 poles
65
70
75
80
85
90
95
0.55 0.75 1.1 1.5 2.2 3 4 5.5 7.5
Power (kW)
Efficiency(%)
WQUATTRO W22 PREMIUM EFF IEC-IE4
Source: ABB

26. 26
Line Start PM motor - Starting
Robbie McElveen, Mike Melfi, Roger Daugherty, Line start permanent magnet motors – Starting, standards and application guidelines,
Petroleum and Chemical Industry Technical Conference (PCIC), 2014 IEEE
The starting “kick” of LSPMs is quite violent, which can lead to accelerated
mechanical wear of the motor and load bearings and/or gears (if any).

27. VSD +Permanent Magnet Synchronous Motors
27
TORQUE-SPEED CURVE OF PMSMs / BLDCs

28. Torque Speed characteristics of PMSM
PMSM - Permanent Magnet Synchronous Motors used in EV
28

29. PM Motor Part-Load Efficiency (11 kW)
29

30. Low Cost Ferrite PM Motors
Based on an innovative geometry for the motor rotor and stator, the NovaTorque
motor uses less costly ferrite magnets to deliver the performance level typically
found in much more expensive rare earth-based permanent magnet motors.
30

31. Super Premium PM motor using Ferrite magnets
31
Motor Compared in Size to Conventional Motor

32. Super Premium PM motor using Ferrite magnets
• The new 11 kW double-rotor, axial-gap motor uses a laminated stator core
based on a low-loss amorphous iron material. The losses from its laminated
material are about 10% of those of conventional electromagnetic steel
laminations.
• An amorphous metal has a disordered atomic structure versus the crystalline
structure of conventional metals, and features a high tensile strength and
extremely low magnetic losses.
32

33. Switched Reluctance Motors (SR)
An SR motor is a doubly salient design
with phase coils mounted around
diametrically opposite stator poles.
Energisation of a phase will cause the
rotor to move into alignment with the
stator poles, so minimizing the
reluctance of the magnetic path. As a
high performance variable speed
drive, the motor's magnetics are
optimized for closed-loop operation.
Rotor position feedback is used to
control phase energisation in an
optimal way to achieve smooth,
continuous torque and high efficiency.
33

34. Switched Reluctance Motors
34
STATOR: 8 POLES
ROTOR: 6 POLES
Passo: pi/6
Bobinas
STATOR: 6 POLES (3 PHASES)
ROTOR: 4 POLES

35. • Simple and robust laminated steel construction: no brushes,
windings, rotor bars or magnets
• Minimal losses in rotor
• no cage or rotor bars
• indefinite stall possible, no limit to frequency of starts
• reduced shaft temperatures and prolonged bearing life
The simple SR rotor has many
advantages over conventional types
which utilise magnets or conductors
SR Motor: Rotor
35

36. SR Motor: Stator
• No magnets: straightforward laminated iron construction
• Simple coil windings: absence of phase overlaps significantly
reduces the risk of inter-phase shorts
• Compact and short coil overhangs make efficient use of active
coil area
Compact end-windings permit
construction of high-performance
motors with unusually flat aspect
ratios.
36

37. Switched Reluctance Motors
Main advantages:
• High efficiency;
• High torque and high speed capability;
• High reliability and long lifetime;
• Simple construction, robustness;
• Low cost;
• Simpler controller (1 power switch per phase);
• High power density;
• Available in different sizes and shapes.
Main disadvantage: ripple torque and high acoustical noise due to the
high vibration level – research is made to improve these aspects. The
controller is always necessary.
37

38. Synchronous Reluctance Motors
38
Source: ABB

39. Advantages:
• No winding and PM in the rotor
• No rotor losses => lower overall losses => higher efficiency and
smaller size (up to two frame sizes smaller than conventional SCIM).
• Low inertia
• Good acceleration performance
• Low manufacturing costs
Disadvantages:
• Low power factor
• Torque ripple
• Requires VSD to operate
39
Synchronous Reluctance Motors

40. • Lower stator temperature => extended insulation lifetime and
higher power density (20-40% in relation to SCIM) and/or higher
efficiency. Possibility of achieving standard power and torque
levels at merely a low class-A temperature rise (60 K).
• For the same rated power, efficiency improvement potential
associated with lower losses:
- smaller size for the same efficiency, and and temperature rise;
- higher efficiency & reduced temperature rise for the same frame size;
- combination of the two previous options (approach used for the
commercial version presented).
40
Synchronous Reluctance Motors

41. 41
Potential efficiency increase due to rotor loss
reduction in SynR Motors
Source: ABB

42. Potential efficiency increase due to rotor loss
reduction in SynR Motors
42
Source: KSB

43. 43
Motor Total Life-Cycle Cost
11 kW motor
15 years lifetime
EU average Electricity Price 2015: 0.119 €/kWh
Price
Increase
+ 100%
+ 20%
IE4
IE5
(€20%)
IE5
(€100%)
+ 20%IE3
Source:ISR-University of Coimbra

44. 44
Investment Overview
11 kW induction motor
EU average Electricity Price 2015: 0.119 €/kWh
2000 and 4000 operating hours per year
Source: ISR-University of Coimbra

45. 45
Motor + VSD Total Life-Cycle Cost
11 kW motor + VSD
15 years lifetime
EU average Electricity Price 2015: 0.119 €/kWh
Source: ISR-University of Coimbra

46. 46
Investment Overview
11 kW induction motor + VSD
EU avg Electricity Price 2015: 0.119 €/kWh
1000 and 3000 operating hours per year
Source: ISR-University of Coimbra