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SMMA
2004 Fall Technical Conference November
3-5, 2004 Conference Chair - John Calico, Moog Components Group* *
SMMA member company Wednesday,
November 3 9:00-5:00
Instructor:
Dal Y. Ohm, PhD, President, Drivetech Inc.* The purpose of this course is to provide fundamental concepts and knowledge necessary to design or apply dc and brushless motor drives for design engineers and field application engineers in the motion control industry. Separate registration required - lunch and refreshment breaks included 12:00-4:00
SMMA Board of Directors Meeting (includes working lunch) 1:00-5:00
Electric Motor Education and Research Foundation (EMERF) Workshop:
Combining the EMERF Lamination Steels Database with Motor Simulation
Programs Instructors:
Steve Sprague, Sales Manager, Proto Laminations Inc.*, and
Dan Jones, President, Incremotion Associates Inc.* The EMERF Workshop will include an overview of the EMERF database for soft irons and steels used in electric motors. This data, available on the EMERF Lamination Steels, Second Edition CD, provides an additional tool for more accurate motor design including magnetic saturation (first quadrant) curves and core loss curves. The EMERF data will be combined with PC-BDC, a SPEED brushless permanent magnet motor design program to illustrate the basics of precision motor design. The workshop will also cover the selection and evaluation process for soft irons, steels and permanent magnets, as they pertain to overall motor performance. 1:00-5:00
Infolytica Optimization Seminar Instructors:
David Lowther, Ph.D., President, and Behzad Forghani, Vice President,
Infolytica Corp.* This
seminar will focus on the practical uses of optimization based
on electromagnetic field simulation for effective improvement
of motor designs. Some background information regarding the optimization
algorithms will be presented and the software features that are
required for a robust design will be discussed. The following
topics will be covered during the seminar:
Several motor design examples will be used to illustrate the operation of an existing optimization tool. Separate registration required - refreshment break included 1:00-4:00
Set-Up for Table Top Exhibitors 6:00-7:00
Registration 6:00-7:00
Beer and Pretzels Reception with Table Top Exhibits Dinner
on your own. Thursday,
November 4 7:30-8:00
Continental Breakfast with Table Top Exhibits 8:00-12:00
Meeting in Session Welcome:
Dave Beth, VP Engineering, Emerson Tool* and SMMA President and
John Calico, Senior Research and Development Engineer, Moog Components
Group*, and SMMA 2004 Fall Technical Conference Chair 8:00-8:30
Introducing the EMERF 3rd Edition CD-ROM on Lamination
Steels EMERF,
the Electric Motor Education and Research Foundation, initiated
the Lamination Steels Research Project to compile and update the
data available to motor designers pertaining to soft magnetic
alloys commonly used in electric motors. The Project has two phases.
The first phase is the collection of existing information, published
on a CD-ROM. The second phase is to research material properties
at high frequencies and at non-sinusoidal excitations. This research
is being pursued by a Consortium of SMMA member companies and
is coordinated through Professor Prag Pillay, 8:30-9:00
Recent Progress on Losses in Lamination Steels, Pragasen
Pillay, PhD, Professor, Department of Electrical & Computer
Engineering, A number of SMMA member
companies have formed a Consortium to develop a better understanding
of iron losses at high frequencies, high excitations, and non-sinusoidal
waveforms, and ultimately, to develop an industry standard. Consortium
member companies include motor and control manufacturers, steel
and lamination manufacturers, an instrument company and a magnetic
software company. The Consortium directs the research efforts
of Professor Pillay and his students at This
presentation is about some studies with finite element modeling.
The study will model small motors and compare them with actual
machines. Time varying simulation and rotating machines simulation
will be used to solve the electromagnetics problem and obtain
the power dissipation from the copper circuits. This will
then form the input to the thermal analysis solver with the aim
to compute the temperature distribution in the machine, depending
on the type of cooling employed in the machine. 9:30-10:00
SMC's - The Powder Metal Alternative Change and innovation in the design of electrical machines is fueling the search for alternative magnetic core materials. SMC’s (Soft Magnetic Composites) offer creative designers a unique soft magnetic material that leverages the shape capability and economic advantages of the powder metallurgy process. This presentation describes the fabrication and application of SMC materials. The features and benefits of powder metallurgy are detailed along with the key features and benefits of SMC materials in electrical machine design. 10:00-10:30
Networking Break with Table Top Exhibits 10:30-11:00 NdFeB for High Temperature
Motor Applications, Steve Constantinides,
Manager Applications and Design, "Neo" is increasingly the material of choice
for motor applications due to a combination of high energy, relatively
low cost and wide availability.
However, in motors operating at and above 120 degrees centigrade
special care must be taken in the selection of material and the
control of over-load such as at start-up and at stall.
This presentation will address issues regarding material
selection and design guidelines.
This
presentation demonstrates methods for calculating the static value
of armature inductance for a PMDC motor. Slot, tooth tip and end
leakage inductance values are developed individually from the
mechanical, electrical and magnetic properties of the PMDC motor.
Calculation of the armature inductance will allow for better analysis
of the performance of PMDC machines, especially at higher rates
of speed, and will be a useful parameter to the controller designer. 11:30-12:00 Starter-Generators: New Solutions, Jonathan Edelson, Principal Scientist, Chorus Motors PLC Starters and alternators have historically always been separate: starters are required to produce high torque at low speeds for short durations. Alternators are generally required to operate at higher speeds, with lower torque and continuous operational capability. Presented is the use of the mesh connection for inverter fed AC induction machines - allowing its use as a starter-generator. Harmonic currents are intentionally used to change the V/Hz ratio that the machine presents to the inverter, dramatically reducing the power silicon required to provide for high torque overloads at reduced speed while starting. In essence, a single winding acts as several different windings, each with its own base speed and torque per current capabilities. The technology allows production of extremely high torque with normal inverter output currents. (Testing has demonstrated low speed torque enhancement of approximately 5x.) A multiple base speed profile is ideal for starter-generators, which require very high overload torque at low speed relative to their normal continuous running torque. 12:00-1:00
Lunch 1:00-1:30
The Application of NdFeB Magnets in Motor and Motion Control:
The Key Issues, Concerns and Solutions NdFeB magnets play a critical role in the motor and motion control industry and are getting popular especially for new motor and motion control applications such as the REPM motor. The major concerns and issues of applying NdFeB magnets involve magnetic performance, consistency, corrosive resistance, thermal stability and cost. Various features of the magnets are required in a case-by-case scenario by the different motor applications, which can be guaranteed through the well-defined and well-designed magnet manufacturing process control. Rotary motors such as the auto drive motor, for example, would require high coercive force and excellent thermal behavior, which requires stringent process control in the coercivity in magnet production. In the case of linear motors, usually used in a room temperature environment without demagnetizing stray field, the requirements will be focused on the high remanence or flux density of the magnets in the productions. Coatings are another major and indispensable issue for sintered NdFeB magnets of motor applications due to its inborn weakness against rigor environments. Different coating technologies have been developed to not only enhance the anti-corrosive performance but also to meet the other requirements of motor makers such as appearance, hardness and surface decoration. Nickel plating is getting popular in many motor applications. However, there are some other emergent plating techniques and applications to be developed to meet the new requirements. 1:30-2:00
SMC – Is there a big pay-off for their use in electric motors? In
recent times there have been several reports and presentations
on material characteristics and devices made of soft magnetic
composites. In this presentation a review of the advantages and
disadvantages of designing with SMC will be highlighted with particular
emphasis on some of the innovations that make them worthwhile
to pursue. 2:00-2:30
Cogging Torque and Torque Ripple Analysis in Brushless DC and
Switched Reluctance Motors This
presentation discusses simulation software with parametric capability. This
capability allows one to use a mathematical expression to define
constructs. These expressions can be simple, or they can
contain any combination of available math functions. Expressions
can be nested or relative to one another as well. Any geometry
construct such as points, lines, transformations, coordinate systems,
faces, etc. can be parametrically defined directly in the Textbox
input area of the interface. This same technology can be
used to construct a suitable mesh for the model so that the mesh
tracks any changes in the geometry automatically. Curvilinear
triangles and quads can be combined in a single model to reduce
computation time and improve simulation accuracy. Specifically
these capabilities were used to examine the nature and sensitivity
of cogging torque and torque ripple in a variety of electric machines. Results
for brushless DC and switched reluctance motors will be discussed
in depth. Soft magnetic composites (SMCs) are today a viable alternative to steel laminations in a range of new applications, such as rotating machinery, sensors and fast switching solenoids. SMC components are successfully manufactured using the powder compaction process. The isotropic nature of the SMC combined with the unique shaping possibilities opens up for 3D-design solutions. If carefully implemented, advantages such as better performance, reduced size and weight, fewer parts and lower cost can be obtained. This presentation focuses on what influence material data has on the motor performance for a given motor model. The study has been carried out using commercial 3D finite element software. With this software it is possible to study the effects of material changes on a defined model. The simulations are carried out with the rotor running at different rotating speeds. Motor performance using different SMC materials is compared regarding dynamic torque and iron losses. 3:00-3:30
Networking Break with Table Top Exhibits 3:30-4:00
Speed/Torque Curves: A Critical Component of Electric Motor Performance
Charaterization For many applications of electric motors, it is necessary to verify that a given motor will meet the torque requirements of the driven load over the entire speed range from zero rpm to full load speed. This requirement is typically evaluated based on the speed vs. toque characteristics of the motor. Traditional methods have relied on dynamometer testing to establish this curve. More recently, test labs have utilized the inherent relationship between rotational acceleration and rotational inertia to derive the torque over the full operating speed of the motor. This paper will discuss the advantages and pitfalls of the acceleration/inertia method and how to avoid them. 4:00-4:30
Dynamic Simulation of Electric Motors The accurate prediction of the performance characteristics of several electric motors requires a transient solution that takes into account the motion of the rotor. There may be eddy currents induced in solid, conducting parts due to the motion of the magnetic fields and, in addition, there are loads on the rotor that affect the motion. While the 2D solution of transient with motion problems has become commonplace and has gained popularity, the solution of such problems in 3D is new. The benefits of transient solutions with motion simulation will be discussed with some practical examples. 4:30-5:00 EMI and EMC Aspects of a Brushless Repulsion Motor, Robert Klimo, VP Engineering, Dynamotors Inc. It is well known that the high frequency switching rates associated with modern PWM inverters used to power induction motors and BLDC motors create a number of problems. These include electromagnetic interference and compatibility (EMI, EMC) issues, poor bearing life due to bearing current, poor insulation life, and corona. The construction of the brushless repulsion motor (BLR) places the power switches on the motor rotor and the switches also operate at low frequency rates, thus eliminating these problems at the source. This
paper will discuss possible causes for these problems as well
the reasons that the BLR motor prevents the problems as opposed
to correcting them. Comparative data between the BLR and conventional
technologies will be presented. 6:00-7:00
Reception with Table Top Exhibits 7:00-9:00
Dinner Friday,
November 5 7:30-8:00
Continental Breakfast with Table Top Exhibits 8:00-8:30
Brushless DC Speed Controls Provide Small
brushless speed controls are challenging the venerable brush dc
speed controls with a significant suite of performance improvements
in smaller sized packages. These performance enhancements, when
combined with longer life, provide users with superior performance
and fast payback of acquisition costs. 8:30-9:00
An Innovative Low Cost Linear Brushless Servomotor The major advantages
of using linear motors and their systems to replace rotary motors
in many applications with linear motion are that they can completely
eliminate the unexpected transmission elements in the systems,
[such as lead-screws, time belts, mechanical gears and rack and
pinion systems,] and have direct linear motion for loads with
significantly high dynamic performance, positioning accuracy and
regulation stiffness. Among these linear motors, linear brushless
servomotors and the systems are highly regarded as they have high
force and force density and can provide the desired dynamics with
high speed, acceleration/deceleration and regulation stiffness.
The conventional linear brushless servomotors, both coreless (cog-free)
servomotors and iron core servomotors, are highly dependent on
the support of high-cost and high-energy rare-earth permanent
magnets (PM) to generate force and high force density. To significantly
minimize the high cost of conventional linear brushless servomotors,
without deteriorating motor force density and performance, becomes
a top priority to motor designers and researcher. The fundamentals of
the related technologies developed to address these needs will
be briefly introduced in the presentation. The presentation will
also review the static and dynamic performance of these servomotors
and have some comparisons between the conventional linear PM brushless
iron core servomotor and the subject servomotor. 9:00-9:30 The Open Directory Project is the largest human edited directory on the web with over 4 million sites listed, 65,155 editors, and 590,000 categories and subcategories. It is source material for major directories such as Google, Lycos, and AOL. You cannot afford NOT to be listed in this directory, and it is absolutely free of charge. Submitting your site for listing is an easy process and should be successful provided you follow a few simple rules.
A
sensor to measure the stator torsional vibration due to torque
ripple produced by a surface mount permanent magnet machine is
first described. The sensor is relatively inexpensive and is straight-forward
to incorporate into a drive system. Experiments are performed
to validate that the voltage produced by the sensor is linearly
related to torque ripple amplitude. Closed-loop controllers that
are based upon cost-function minimization are then described that
adjust the stator current harmonics applied to the machine to
achieve a commanded average torque while mitigating measured torsional
vibration. Simulation and experimental results are used to demonstrate
the effectiveness of the control techniques. 10:00-10:30
Networking Break with Table Top Exhibits 10:30-11:00
Development of a High Voltage PMDC Motor for an Advanced Dishwasher In
today’s competitive environment, dishwasher machine manufacturers
are developing units that do more work with more intelligence
so that consumers can enjoy a higher level of value. This challenge
of increased value brought Electrolux and Johnson Electric engineers
together to collaborate on enhancing dishwasher performance by
focusing on the pump and its motor. The team created a list of
needs, including; variable
speeds for different dishwasher contents The
collaborative effort resulted in the development of a high-voltage
permanent magnet direct current (HV PMDC) motor to provide variable
speed and power to drive the pump in the dishwasher. It improved control over wash cycles and permitted
the same machine to effectively wash all manner of items, saving
water and electricity. 11:00-11:30
Component Integration and Tolerance Reduction Enabled via Thermoplastic
Encapsulation Over
the past ten years, thermoplastic encapsulation of motor components
has enabled improvements in system cost and performance. Primary
drivers of these improvements are parts consolidation and manufacturing
simplification, through the integration of insulating components,
mounting components and termination features. Additional benefits
are realized in thermal dissipation, reduction of both structural
and audible vibration, and hermetic sealing.
As a process, encapsulation via injection molding is extremely
repeatable; total cycle times are typically 20 to 60 seconds.
Because thermoplastic encapsulation reduces manufacturing steps,
component count and manufacturing tolerances, it is a powerful
enabler of both Six Sigma and Lean Manufacturing efforts.
In
this presentation, the manufacturing and performance advantages
will be demonstrated through current design examples and new concepts.
It will be shown how recent innovations have further increased
the ROI of this approach to motor manufacturing. 11:30-12:00 Estimation of The Magnet Power Loss in Permanent Magnet Motors Using 2D Finite Element Analysis, Z. Rahman, Principal Engineer WaveCrest Laboratories, LLC A
simplified 2 dimensional finite element method is developed to
estimate the eddy losses in the magnets of any permanent magnet
motor. The developed method starts by estimating the magnet eddy
losses by using the 3 dimensional eddy current solver. The results
obtained are then used to modify the true conductivity of the
magnet material so that the 3 dimensional loss effects can be
captured in the 2 dimensional loss analysis. The modified conductivity
is later used in the 2 dimensional transient solver to accurately
predict the eddy losses in the magnets. The paper also demonstrates
a simple relationship between the length to width ratio of the
magnet dimension with the true conductivity of magnet material.
The proposed technique provides reasonable accuracy in loss estimation,
swiftness in calculation and can approximate the effect of magnet
segmentation in axial direction even in a 2 dimensional simulation
environment. 12:00-4:00
EMERF Board of Directors Meeting (includes working lunch) 10.06, .04
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