Control Engineering Motors, Drives, & Motion Control Newsletter for April 2002

By Frank Bartos June 4, 2002

In this issue:

Reality in ac drive markets
More results from motion control survey
Bypass feature ‘hot’ for ac drives
SERCOS goes electrohydraulic as well

Knowledge is power
Control Engineering in April
Seminars, conferences
Control Engineering News

Reality in ac drive markets

Do you ever wonder how market study results remain the same in good times and bad? Here is a reality check.

A February 2002 market research and technology forecast report, ‘AC Drives Outlook for North America 2002-2006,’ from Drives Research Corp. (DRC, San Juan Capistrano, Calif.) puts some much-needed realism into market growth figures. In contrast to other recent studies, DRC sees just the start of modest growth for ac drives in 2002, following ‘a double-digit decline in 2001.’

In 2001, some of the largest ac drive suppliers in North America absorbed major sales slumps. At the same time, a number of second-tier suppliers ‘managed to increase sales revenues through focused application-specific product and marketing solutions,’ according to DRC’s report.

For 2002 nearly 3% growth is forecast for North American ac drives. Prospects for the next two years are brighter, indicating growth in the 4-7% range. The longer-term outlook looks even more promising. ‘We expect the billion-dollar-plus North American ac drives market to post nearly 6% CAGR [compound annual growth rate] through 2006, compared to 8% achieved from 1995 to 2000,’ says Tom Kaporch, president of Drives Research and principal author of the report.

Propelling the growth are demands for energy conservation, higher productivity, upgrading of neglected infrastructures, plus emerging applications (marine propulsion, traction drives other than automotive, and commercial/household appliances and products). Drives Research Corp., a market research and management consultant firm, specializes in electronic motor drives, controls, and electric motors.

For more information, visit https://www.drivesresearch.com

A longer version of this item appears in April 24, 2002, Daily News at /archives/news/2002/April/fb0424b.htm

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More results from motion control survey; care to comment?

Recently, I was involved in an extensive ‘Motion Control Trends Survey’ of readers of Control Engineering and Design News magazines, conducted by Cahners Research.

The survey explored views of users and specifiers of motion technology. I shared some results with you, along with my analysis, in prior newsletters. This batch of results looks at operator interfaces used with motion-control systems. The survey ranked industrial PCs as the most popular human-machine interface (HMI), at 60.8%, for connecting to motion-control systems. Full-featured operator panels followed closely with a 59.8% response. Touchscreen technologies (54.1%) and flat-panel displays (45.9%) rounded out the four most widely used HMIs associated with motion systems. Next came a second tier of interfaces that included keypad with LCD screen (23%); joystick or mouse (22%); keypad with LED display (17%); and DCS workstation (15%).

More survey results can be found in a Special Supplement to March 2002 Control Engineering, also in the ‘Motion Trends 2002’ article in the same issue. See /archives/2002/ctl0302.01/020301.htm

Do you have comments on these findings? E-mail me at fbartos@cahners.com

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Bypass feature ‘hot’ for ac drives

Judging by a spate of recent announcements, the demand for a bypass feature on ac drives must be heating up.

Saftronics (Fort Myers, Fla.) has combined two technologies-its latest GP10 drive and ‘Smart Bypass’ (patent pending)-to obtain a highly efficient HVAC bypass system. Called FPC5010S, the system monitors drive loads and speeds, automatically transferring the motor from adjustable-speed drive (ASD) control to full-speed, across-the-line operation as needed. Switching the drive from the circuit is done to improve system efficiency or reduce harmonic distortion when operating conditions warrant the change. ‘Smart Bypass’ controller continues to monitor demand and returns the motor to ASD control when conditions return to normal.

A new Side-by-Side Electronic Bypass, integrated into ACH 400 ac drive from ABB (New Berlin, Wis.), features two contactors for bypass operation. One contactor works with the main disconnect switch or circuit breaker, while the second contactor is linked to a service switch that disconnects the drive for maintenance, but allows the motor to run in bypass mode. The bypass protects the motor against input phase-loss in either drive or bypass mode. It also accommodates

Danfoss Drives (Loves Park, Ill.) now offers a Bypass package configuration for its VLT 2800 Series ac drives. Available in two- and three-contactor versions, Bypass can switch the motor to drive control, full-speed bypass, or disconnect it from either operating mode. Among standard features of the package are a door-interlocked input disconnect switch or circuit breaker, ‘Drive’ and ‘Bypass’ indicator lights and Class 20 overload protection when the motor runs in bypass.

Yaskawa Electric America (Waukegan, Ill.) offers Model C21 3-Contactor Bypass Control with its GPD 506/P5 Variable Torque AC Drive, allowing ac induction motors to run under drive control or ac line current. Bypass is needed in applications where fans, pumps, chillers, and other vital equipment must run continuously. Bypass control uses both input as well as output drive contactors for added protection when the drive is isolated. Electric interlock of the contactors, an input circuit breaker with door interlock, and motor overload relay are among standard features.

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SERCOS goes electrohydraulic as well

Virtually all publicity and information surrounding SERCOS (SErial Realtime COmmunications System) has been in electric drive and motion control applications. SERCOS is a standardized interface (IEC 61491) for communication among controls, digital drives, and I/O modules. It is based on a fiber-optic ring with transmission rates now up to 16 Mbit/sec. However, this digital communication interface also has a place in electrohydraulic servo drives.

At the recently concluded Hannover Fair in Germany, Bosch Rexroth (Lohr, Germany; Hoffman Estates, Ill.) exhibited closed-loop electrohydraulic valves and positioning systems, controlled by a hydraulic drive that uses the same SERCOS interface and protocol. Ability to apply SERCOS across electric and electrohydraulic control technologies widens the protocol’s value by reducing the number of system components, along with simplifying maintenance and operator training.

More than 70 manufacturers presently supply SERCOS interface products. Interest groups are established in Europe, North America, and Japan. Among the 14 current members of SERCOS North America are:

Automation Intelligence (Duluth, Ga.)

Beckhoff Automation (Minneapolis, Minn.)

Bosch Rexroth (Hoffman Estates, Ill.)

Giddings & Lewis (Fon du Lac, Wis.)

Industrial Indexing Systems (Victor, N.Y.)

Danaher Motion (Simsbury, Conn.)

Moog Inc. (East Aurora, N.Y.)

Motion Engineering Inc. (Santa Barbara, Calif.)

Rockwell Automation (Milwaukee, Wis.)

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References: Knowledge is power

New references can add to the knowledge of readers and motion-control professionals.

‘Permanent Magnet and Electromechanical Devices,’ by Edward P. Furlani, is a prime reference on the theory and methods needed to analyze/design such devices. Extensive coverage spans applied magnetics, a survey of magnetic materials, magnetostatic analysis, magnetic circuit theory, electromechanical energy conversion theory, and design/analysis of rare-earth permanent magnet (PM) structures. More than 60 solved examples from practical applications complement the theory. ISBN: 0122699513. The book is available from Academic Press

‘Dictionary of Drives: CD-ROM English-German’ (2nd Edition), by Thomas Antoni, provides a gamut of terms related to drive systems, automation, and other fields. The updated edition contains entries from new areas, for example, advanced automation and fieldbus technology, and 40% more keywords, for a total of more than 60,000 entries with 120,000 translations. ISBN: 3-8957-8171-1. The reference is available from John Wiley & Sons Inc.

‘Permanent Magnet Technology: Design and Applications’ (2nd Edition), by Jacek F. Gieras and Mitchell Wing, covers up to date developments in PM brushless motors for electromechanical servo drives in a wide range of applications. New or expanded coverage includes cost evaluation, dynamic modeling, and motion control of PM motors; rotor position sensing of brushless dc motors; sensorless motors; multidisk motors; and more. ISBN: 0-8247-0739-7. From Marcel Dekker Inc. at https://www.dekker.com/servlet/product/productid/0739-7

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Control Engineering in April

Each month you will find information pertinent to this sector in the magazine’s in-print issue.

In the News section a graphic updates you on the North American robotics market, summarizing information obtained from the Robotic Industries Association (Ann Arbor, Mich.)

An exclusive preview of a line of intelligent contactors and starters with all 24-V dc control from Eaton/Cutler-Hammer (Milwaukee, Wis.) leads off this month’s Products & Software section. NEMA- and IEC-type units with a wide range of power and current ratings are available.

National Instruments’ (NI, Austin, Tex.) new development tool, Motion Assistant, is here to help speed up motion-system programming and prototyping. The software works with NI motion controllers and can generate code for LabView.

Brushless gearmotors from Thomson Micron Div. (Ronkonkoma, N.Y.) incorporate a planetary gearhead, brake, and feedback device into the motor structure. Three motor sizes deliver continuous torques up to 28 Nm (248 lb-in.).

Oriental Motor (Torrance, Calif.) offers its Nanostep CFKII Series high-resolution driver (125,000 microstep/rev) and 5-phase step motor combination that claims up to

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Seminars, conferences

The 21st Annual ‘Conference on Properties and Applications of Magnetic Materials’ will take place at Illinois Institute of Technology (IIT, Chicago, Ill.), May 13-15, 2002. Wide-ranging topics on various aspects of magnetic materials are scheduled. A special tutorial on ‘Power Electronics and Motor Drives’ will be included in the first of four sessions. For more information and registration, email Ms. Bonnie Dow, IIT conference secretary, at bonnie@ece.iit.edu .

The Electric Apparatus Service Association (EASA, St. Louis, Mo.) is set to hold its annual convention and exposition June 16-19, 2002, at the Cincinnati Convention Center in Cincinnati, O. Along with some 150 exhibitors, technical presentations will focus on application, maintenance, and troubleshooting of motors, drives, and ancillary equipment. Breakout sessions will be part of the convention, including ‘Motor Management’ and related planning methods to cut energy costs-part of a national campaign called Motor Decisions Matter (MDM). The Consortium for Energy Efficiency (Boston, Mass.) coordinates the MDM campaign.

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Control Engineering News

Control Engineering Online includes nine other e-mailed newsletters besides this one, Daily News, Control Engineering Europe, and searches of the site, Control Engineering Buyer’s Guide, and Automation Integrator Guide Online; go to /

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