`
`”Super Premium” Efficiency
`Motors are Now Available
`
`By Gilbert A. McCoy, P.E.
`Energy Systems Engineer,
`Washington State University
`Extension Energy Program
`
`The Energy Independence and
`Security Act of 2007 mandates
`that only Premium Efficiency
`general purpose motors be
`imported or sold in the United
`States after December 19, 2010.
`Covered motors include low
`
`voltage 1 to 200 horsepower (hp)
`motors running at synchronous
`(nominal) speeds of 1200, 1800,
`and 3600 revolutions per minute
`(RPM).
`
`While the US. was requiring
`deployment of the highest
`efficiency class of motors available
`at that time (2007), the bar was
`soon raised again. In 2008, the
`International Electrotechnical
`
`Commission (IEC) published a
`new global efficiency standard
`for 60 Hz motors that includes
`
`a ”Super Premium” efficiency
`level. This level was established
`
`to encourage the transformation
`of a competitive market for even
`more efficient motors. At the time
`
`the Super Premium or ”reach”
`standard was published, it was
`
`noted that qualifying motors were
`not yet commercially available
`and that motor manufacturers
`
`might have to go beyond
`alternating current (AC) induction
`motor technology to achieve
`the required minimum full-load
`efficiency values.
`
`That mission has now been
`
`accomplished. The best available
`and emerging motor technologies —
`such as permanent magnet (PM)
`motors and switched reluctance
`
`(SR) motors — can achieve efficiency
`levels significantly higher than
`Premium Efficiency induction
`motors.1
`
`Permanent Magnet
`Motors
`
`Long used in servo motor applica-
`tions, PM synchronous motors
`are increasingly being used in
`industrial motor drive systems. PM
`motors use powerful ceramic or
`rare earth neodymium iron boron
`(NdFeB) magnets attached to the
`surface of the rotor or interior to
`the rotor in order to establish a
`
`permanent magnetic field. This
`design replaces the traditional
`aluminum rotor cage of the
`
`WASHINGTON STATE UNIVERSITY
`@ EXTENSION ENERGY PROGRAM
`
`induction motor and significantly
`reduces the secondary circuit
`rotor IZR (electrical resistance)
`losses. The PM motor is designed
`for variable speed operation and
`must be controlled by an inverter
`or variable speed drive that is
`specifically developed so PM
`motors can start and achieve full
`
`speed properly. PM motors have
`an inherently high power factor
`and have been demonstrated
`
`to exceed the Super Premium
`efficiency levels even when
`controller losses are included.1
`
`Efficiency and power factor tend
`to drop when conventional AC
`induction motors are designed for
`low operating speeds. PM motor
`designs, however, make it pos-
`sible to combine high efficiency,
`low speed and high torque in
`a single package, making them
`ideal for applications that would
`otherwise require inefficient and
`maintenance-intensive gearboxes
`or gear motors. PM motors can
`be built much smaller than an
`AC induction motor of the same
`
`horsepower rating and come
`in reduced frame sizes. The
`small size and reduced materials
`
`requirements results in a ”power
`
`www.energy.wsu.edu
`
`Nidec Motor Corporation
`IPR2014-01121
`
`Exhibit 2023 - 1
`
`Nidec Motor Corporation
`IPR2014-01121
`
`Exhibit 2023 - 1
`
`

`

` Energy Efficiency Factsheet: ”Super Premium” Efficiency Motors 0 Page 2
`
`Figure 1
`Full-Load Efficiency Values for PM Versus
`NEMA Premium Efficiency Motor Models
`
`Courtesy of Baldor Electric
`
`
`
`PM
`
`— — Premium Efficiency"
`
`
`
`- - - -|EEE 841
`— - — E nergy E fficient
`
`
`
`
`
`
`
`
`
`
`9O
`
`dense” machine having a torque-
`to-weight ratio about twice that
`of conventional AC induction
`
`motors with a weight savings of
`nearly 50 percent?!3
`
`For small motor sizes, the
`efficiency of the PM motor may
`increase by 10 to 15 percent
`when contrasted with older stan-
`
`dard efficiency motors at the same
`load point.4 The relative full-load
`efficiency of PM versus energy
`efficient and NEMA Premium
`
`Efficiency motors of various horse-
`power ratings is shown in Figure
`1. These efficiency gains hold over
`the entire range of typical motor
`loads. While PM motors require
`additional costs for their rotor
`
`magnets, their light weight means
`that they have greatly reduced
`steel and copper costs relative to a
`Premium Efficiency motor. Some
`manufacturers have established
`
`rating equivalent pricing strate-
`gies such that PM motors are now
`cost-effective when compared to
`a conventional Premium Efficiency
`motor and adjustable speed drive
`(ASD) combination.‘
`
`Due to their light weight, high
`torque, and low inertia, PM
`motors are often specified for
`electric vehicle hub motor drives
`
`and for regenerative elevator
`drives. Industrial applications for
`which PM motors are suitable
`
`include adjustable speed pumps,
`fans and compressors, plus
`extruders, conveyors, crane and
`hoist systems, pumps, winders
`and printing presses.
`
`Baldor Electric currently offers
`1800 RPM totally enclosed
`blower-cooled PM motors and
`
`controllers in the 10 hp to 150
`hp size range as standard product
`offerings. Compact, low speed
`
`
`
`98
`
`96
`
`94
`
`92%EFFICIENCY
`
`88
`
`86
`
`100
`
`1000
`
`HP
`
`pancake designs are available
`for specialty applications such as
`cooling tower fan motors.
`
`For additional information, contact
`Rich Schaefer, Baldor Electric
`Company, (864) 382-2722.
`Rrschaefer@baldor.com
`
`Switched Reluctance
`
`Motors
`
`Like the PM motor, a switched
`reluctance (SR) drive system
`requires both a motor and an
`electronic power converter or
`controller that controls both
`
`torque and speed. The controller
`eliminates low speed cogging
`(jerky motion) by switching motor
`phases on and off in relation to
`the rotor position. The motor
`cannot be used without the
`
`converter and cannot be used
`with a conventional variable
`
`frequency drive or inverter. Unlike
`
`Nidec Motor Corporation
`IPR2014-01121
`
`the PM motor, the Super Premium
`efficiency SR motor has a rotor
`that does not have magnets,
`rotor bars or windings. The rotor
`is essentially a piece of shaped
`iron, and the SR motor design
`exploits the fact that forces from
`a magnetic field on the rotor iron
`can be many times greater than
`those on the current carrying
`conductors. SR motors are rapidly
`moving from the servo and hybrid
`electric vehicle drive arena to
`
`industrial applications such as
`screw compressors, blowers and
`high speed pumps, and low speed
`high-torque applications such as
`extruders, conveyors and feeders.
`SR motors are often used in
`
`applications that require a systems
`solution such air conditioning
`compressors, weaving looms,
`laboratory centrifuges, and pumps
`used in reverse osmosis systems.5
`The SR drive system offers many
`
`Exhibit 2023 - 2
`
`Nidec Motor Corporation
`IPR2014-01121
`
`Exhibit 2023 - 2
`
`

`

`Energy Efficiency Factsheet: ”Super Premium” Efficiency Motors 0 Page 3
`
`benefits, including:6
`0 An SR motor can produce
`up to twice as much power
`as a conventional AC
`
`motor when compared on
`a size basis.
`
`0 SR motors are of simple
`design, are rugged, and
`cost less to manufacture
`than conventional
`induction motors.
`In constant and variable
`
`0
`
`torque applications,
`SR motors have a high
`turndown ratio and can
`
`maintain high torque and
`flat system efficiency over a
`broad speed range.
`0 High starting and
`acceleration torques and
`high motor speeds are
`available.
`
`0 The SR motor can with-
`
`stand high temperatures
`and exhibits extremely
`high short-term overload
`capability.
`0 SR motors can be run
`either forward or backward
`
`as a motor or a generator.
`0 Because the rotor runs
`
`relatively cool, the SR drive
`requires only a simple
`thermal management
`system.
`
`Like the PM motors, the SR
`motors are available in NEMA
`and IEC frames. Nidec Motor
`
`Corporation can provide SR
`motors with drives in the 30
`
`hp to 335 hp size range with
`base speeds from 200 RPM to
`ten thousand RPM or more
`
`depending upon application
`requirements.
`
`For additional information
`
`contact Rob Boteler, Director
`
`Figure 2
`Typical Switched Reluctance Motor Construction
`
`
`
`Wound Stator
`
`of Marketing, Nidec Motor
`Corporation, (314) 595-8387.
`rob. boteler@nidec-motor.com
`
`Line Start PM Motors
`
`The line start PM motor (LSPM) is
`a hybrid that has a conventional
`three-phase distributed winding
`in the stator (identical with con-
`ventional induction motors), has
`a rotor with an aluminum cage
`and internal permanent magnets,
`but starts and accelerates directly
`connected to the line and without
`
`the need for a controller. LSPM
`
`motors provide high torque,
`operate at a fixed synchronous
`speed regardless of load, and are
`suitable for driving low inertia
`loads. LSPM motors also come in
`the same frame sizes as conven-
`tional induction motors. As there
`are no resistance losses in the alu-
`
`minum rotor cage, LSPM motors
`have a higher efficiency than a
`Premium Efficiency motor and can
`achieve Super Premium efficiency
`levels. They operate with the
`same current and power factor
`as Premium Efficiency induction
`motors and do not require a
`feedback device or encoder.’
`
`Similar to PM motors, due to the
`high strength rotor magnets, care
`
`must be taken when removing or
`inserting the motor rotor. These
`motors are available in NEMA
`
`Design A ratings from 1 hp to
`10 hp at a synchronous speed of
`1800 RPM and from 1 hp to 5 hp
`at 1200 RPM.
`
`For additional information contact
`
`Dale Basso, Low Voltage Motor
`Manager, WEG Electric Corp,
`(678) 534-4667. dbasso@weg.net
`
`Applications Overview
`PM and SR motor drive systems
`should be considered for the
`
`following types of industrial
`applications:2
`0 Where the application
`requires speed control, i.e.,
`where an adjustable speed
`drive (ASD) is required for
`speed regulation.
`0 When driven equipment is
`in operation for over 2000
`hours per year.
`0 When an old standard
`
`efficiency motor is driving
`a centrifugal (e.g., pump
`or fan) load with throttled
`or damper flow control
`and can be replaced with
`a variable speed PM or SR
`motor and controller.
`
`Nidec Motor Corporation
`IPR2014-01121
`
`Exhibit 2023 - 3
`
`Nidec Motor Corporation
`IPR2014-01121
`
`Exhibit 2023 - 3
`
`

`

`Criteria
`
`Maturity of technology
`
`Power density
`
`High starting torque
`Cool rotor
`
`Pancake profile capabilities
`
`Maximum speed
`
`Maximum speed range: base to top speed ratio
`
`High peak efficiency
`
`Flat efficiency over a wide speed range
`
`Loss of controls / effect of back Electromotive Force (EMF)
`
`
`
`Energy Efficiency Factsheet: ”Super Premium” Efficiency Motors 0 Page 4
`
`Table 1
`
`Variable Speed Drive System Comparison
`Source: Nidec Motor Corporation
`
`.
`Inductlon
`
`Permanent
`
`Switched
`
`Motors
`
`Magnet (PM) Reluctance
`Motors
`(SR) Motors
`
`High temperature capability
`
`Noise, vibration
`
`Torque ripple
`
`Robust, fault tolerance
`
`Sensorless control capability
`
`Low Apparent Power (VA) demand
`
`0 Operations involve
`frequent starts and stops
`(this is a good application
`due to the low inertia of
`
`PM and SR motors).
`0 Where small motors
`
`operate at partial load a
`good deal of the time.
`0 Where the PM or SR
`motor can be used in a
`
`direct drive configuration
`to displace a two-speed
`motor with gearbox (Le.
`a cooling tower fan drive
`motor), a gear motor, or a
`belted power transmission
`system.
`In vertical pump-mount
`applications where resonant
`frequencies must be
`avoided.
`
`0
`
`Conclusion
`
`References
`
`In order to provide the ”best
`available" motor for a given
`application, motor purchasers
`must be fully aware of motor
`costs and system performance
`characteristics. Table 1 provides
`a comparison of the typical
`operating characteristics of
`available variable speed drive
`motors and controllers.
`
`‘ Anibal T. de Almeida,
`”Super Premium Class,”
`Faktor, No. 28, October
`2010.
`
`2 Swiss Federal Department
`of the Environment,
`Transport, Energy and
`Communications,
`”Economic Viability,
`Applications and Limits
`of Efficient Permanent
`
`Magnet Motors,” 30 June
`2009.
`
`3 Frank]. Bartos, ”IPM
`Motors for Highest Energy
`Efficiency,” Control
`Engineering, 1 October
`2008.
`
`Nidec Motor Corporation
`IPR2014-01121
`
`Exhibit 2023 - 4
`
`Nidec Motor Corporation
`IPR2014-01121
`
`Exhibit 2023 - 4
`
`

`

`Energy Efficiency Factsheet: ”Super Premium” Efficiency Motors 0 Page 5
`
`WSU Extension
`
`Energy Program
`Mission Statement
`To advance environmental
`
`and economic well being by
`
`providing unmatched energy
`
`services, products, education,
`and information based on
`
`world-class research.
`
`© 2010
`
`Washington State University
`Extension Energy Program
`
`This publication contains material
`written and produced for public
`distribution. You may reprint this
`written material, provided you do
`not use it to endorse a commercial
`product. Please reference by
`title and credit the Washington
`State University Extension Energy
`Program.
`
`Note: Neither Washington State
`University Extension Energy
`Program, nor any affiliates to the
`University or Extension Programs,
`endorse any of the products
`mentioned herein.
`
`WSUEEP10-042 0 December 2010
`
`4 Anibal T. de Almeida,
`”Time for a Change,”
`Faktor, No. 28, October,
`2010.
`
`Rob Boteler, Nidec
`
`Motor Corporation,
`Presentation, ”SR Motor
`Drive Technology:
`Applications, Operation
`and Performance.”
`
`Switched Reluctance
`
`Drives, Ltd., ”Switched
`Reluctance: The Most
`
`Significant Technological
`Advance in Variable-Speed
`Drives for Generations,”
`2002.
`
`Dale Basso, WEG Electric
`Corp., Presentation,
`”WEG Quattro Super
`Premium Motors: Line-
`
`Start Permanent Magnet
`Motors.”
`
`Nidec Motor Corporation
`IPR2014-01121
`
`Exhibit 2023 - 5
`
`Nidec Motor Corporation
`IPR2014-01121
`
`Exhibit 2023 - 5
`
`