Frank J. Bartos, P.E.
Motor drives, power-switching transistors and microprocessors, sophisticated control algorithms, software influences, and mechatronic integration are among the standout electronic motion control developments.
Automation tales in motion: Great changes have taken place in motion control systems over the past 60 years. From proprietary, “black-box” controllers and early analog drives, electronic advancements have led to today’s largely automated controls that rely on digital signal processors, accurate motor models implemented in software, and ability to connect with other systems in a facility. Four online extensions, with a historical photo gallery, cover more functions and history.
Motor design and motion control: Earliest electric motor designs reach back 150 years. While motor principles have changed little over time, much has changed in how motors are manufactured and packaged. Advances in construction materials—especially magnet materials—dramatic physical size reductions, and design innovations have occurred. Some of these developments are explored in this online extension (1 of 4) of the main article “Electronic motion control, then and now,” in Control Engineering’s 60th anniversary issue, September 2014.
Energy Efficiency in Motor Driven Systems (EEMODS)—a notable international conference on electric motors, drives, and numerous related systems—drew some 150 attendees from industry, academia, government, research labs, and other service organizations to Alexandria, VA (greater Washington, D.C. area) during Sept. 12-14, 2011, to discuss, debate, and promote advances in energy-efficient technologies. This part 2 of two articles covers developments in efficiency standards and newer motor technologies.
The latest edition of Energy Efficiency in Motor Driven Systems (EEMODS)—a notable international conference on electric motors, drives, and associated systems—had the objective to explain and promote commercial advances of energy-efficient systems to OEMs, energy users, and other stakeholders. This part 1 of two articles covers system issues, recommendations, and a market overview of efficient motors and drives. See graphics.
Some drive manufacturers do not agree on the merits of medium-voltage (MV) drive operation without an input transformer. The following pro and con comments come from companies with and without a transformerless MV drive on the market.
In very basic terms, a variable-frequency drive (VFD) consists of three sections, moving from the drive’s input to output. A rectifier (or converter) changes ac input to dc, followed by a dc link that serves as an energy storage circuit, and then an inverter switches dc back to variable frequency ac output.
Advancing Technology: Sensorless vector control, power factor control, and higher temperature operation are among recent silicon developments.
Motor control and motion control have similarities and different objectives; motor control typically needs less precise regulation of speed and torque than motion control. See suppliers.
List shows manufacturers active in the all-electric tube bending machine marketplace worldwide; manufacturers also make traditional hydraulic-powered machines for the larger market sector.
Actuated by servo motors, this new breed of CNC machines boasts as many as 15 motion axes on some models.
Permanent magnet brushless synchronous motors have moved beyond traditional applications with higher efficiency than induction machines.
variable-frequency drives (VFDs) provide dramatic energy savings in myriad applications with varying loads and speeds. While power and energy savings are key benefits, VFD efficiency is also of interest because drives can experience significant efficiency losses at partial load operation-much like electric motors.
Although an effective date isn’t expected before 2011, mandatory minimum energy performance standards (MEPS) for electric motors are coming to Europe in 2009. This will promote energy-efficient (EE) motor systems that can save up to 30% of the 70% of industrial electricity used by motors, according to Prof.
Industry “workhorse” ac induction motors have been at the forefront of energy-efficient (EE) developments due to their huge installed numbers that account for a significant part of total electricity usage. Efficiency standards and mandatory minimum energy performance specs have spurred EE designs for these general-purpose motors in the 1-500 hp (0.
In this era of high concern for energy consumption, readily available energy-efficient motors top the 96% mark, electric drives reach 95%, and many appliances and consumer devices exhibit rising efficiency. What, then, makes 60% thermal efficiency so special? It’s a much different scenario for power generation.
Non-volatile flash memory has played a large role in enabling the performance we see in today’s microprocessors and computers. To store data, flash memory relies on controlling electrons stored in a transistor’s gate circuit. Flash provides attractive read-write speeds with reasonable power consumption.
Efficient automation systems translate into true energy savings. A major step in that direction has focused first on industrial electric motors because of their vast installed base and continuing growth. Researchers say 300 million industrial motors are running worldwide, with 20 to 30 million being added yearly.
The short answer to the question, “What's better than a good microprocessor?” is “one with multiple execution cores embedded into the same-sized semiconductor package.” But you should know more. An appropriate comparison must first recognize that performance of normal, single-core (“good”) microprocessors has increased almost without limit over many generations.
It’s the only motion-control method able to run in open loop, without the need for position feedback. This makes stepper-motor-based systems simpler than servo motion systems, with the lower cost of step motors adding to the attraction. Coupled with other evolving design enhancements—such as hardware miniaturization and higher torque density—stepper systems stay competitive fo...
The old adage, “if it ain’t broke, don’t fix it,” may have had its day—and may still apply to some situations—but is unacceptable in today’s lean manufacturing environments. Critical production processes and automated manufacturing systems can’t afford the cost of unplanned downtime amounting to thousands of dollars per hour.
The term "form factor" in the context of industrial circuit boards, single-board computers (SBCs), and embedded control cards refers to the shape and physical size of these products. However, exact terminology is elusive in practice. Other terms are too often interchangeably used to convey the notion of a board-level product form factor.
An ever-increasing number of transistors and more performance being squeezed into chip-level products (and embedded microprocessors) of shrinking physical size are unmasking a critical power consumption issue. Power usage rather than operating speed is becoming the performance bottleneck, as silicon device production continues to shrink to 90 nanometer (nm), 65 nm, and even smaller process nodes.
Less numerous than their ever-present low-voltage "cousins," medium-voltage (MV) ac drives are out there in growing numbers, doing heavy-duty motor control in diverse, rugged applications. They span industries from mining, sugar-cane processing, and liquefied-gas handling stations to fluid-power system test stands, fan/pump flow optimization in power-generating plants, and control of mobile off...
There's a lot of technology to "update" at a confluence of 10 thematically integrated trade shows in one location, as will be the case at Hannover Industrial Fair in Germany, April 24-28, 2006. Visitors will be afforded a wide sweep of state-of the-art technology at this event, billed as "the world's leading trade fair for industrial and automation technology"—as well as the ability to co...
Better known in relatively small physical sizes and lower power applications, brushless permanent magnet (PM) motors can be made in virtually any size, with no real technological constraints. Large brushless PM motors are not particularly new. They're available from select manufacturers, which now seek to overcome past economic issues that have limited their numbers.