Defining Trends in AC Motor Drives
“By combining functions and cutting part counts, ABB has reduced the size of its drives while enhancing their reliability,” the authors said.
Drive setup and programming can be relatively easy or more complicated, based on the user’s knowledge and comfort level. The more-simplified setup procedure uses a harmonized keypad and software wizards to ease programming in the company’s entire drive family, the authors said. “More complex programming can be carried out using the Adaptive Programming utility; parameters can be transferred between drives using ABB’s patented FlashDrop technology.”
Such advances are part of “an ongoing effort to offer cutting-edge technology in high-performance, yet user-friendly systems,” states the paper.
TECHNOLOGY DRIVES NEW USESDrives traditionally have been used for powering pumps, fans, and conveyors. “While they will continue to be used in these applications, today’s end users have a very different approach to that of a decade ago,” the authors pointed out.
“The question, ‘What does it do,’ has been replaced by the expectation that the drive will just do it,” the paper states. “This shift in attitude brings with it the assumption that the drives are simple to buy, simple to install, simple to start up, simple to commission, and simple to own and run.”
In new applications (such as exercise machines, pizza ovens, honey centrifuges, and car washes), OEMs are demanding simplicity. According to ABB, a recent survey showed that simple controls and setups (70 percent) and convenient operator interfaces (53 percent) were rated “very important” by ac drives users.
SMALLER AND SIMPLERDrives were once considered exclusive to commercial-industrial mechanical systems. They are now small and simple enough to use in domestic appliances. “Drives have become smaller, more capable, easier to use, and cheaper, by orders of magnitude,” the authors wrote.
Smaller drives are easier to install, he continued. “Panel builders are able to fit more drives into a standard cubicle, so the whole panel can be smaller. This allows the use of smaller and less-costly control rooms. It also becomes easier for OEMs to fit drives into their equipment.”
According to ABB, drive size has decreased ten-fold over the past 10 years. The use of fewer components, greater packing density, improvements in semiconductor technology, and improved cooling techniques have all contributed to the reductions in drive size.
When a piece of equipment uses fewer components, it tends to cut costs, the authors noted. “ABB predicts that over the next few years, the parts count of its drives will be reduced by approximately 20 percent through the use of integrated electronics to eliminate separate components, such as external flash and RAM memories and analog/digital converters. Mechanical parts are also being integrated, for example, by combining frames and enclosures, allowing them to perform multiple functions.”
Fewer parts also means there are fewer components to break. Fewer parts also mean fewer interfaces and mechanical fixings, which are often a source of failures.
Today’s smaller semiconductors need less cooling within the drive. This, in turn, allows the use of smaller heat sinks and reduced air volumes inside the drive - the result of which is increasingly smaller drives. The only limitations are the terminals because these must accommodate cables that are large enough to carry sufficient current to the drive.
INCREASED FUNCTIONALITYSoftware developments are making it possible for these smaller drives to actually do more. The software can monitor, diagnose, configure, and archive information, the authors said. Drive setups are performed using software, then downloaded to the appropriate drives.
“The setup information is archived for future retrieval,” states the paper. “To obtain the full benefit of this technology, however, operators must still refer to the user manual.” ABB said it is working on intelligent control panels that will “significantly decrease the need for paper-based manuals.
“The secret, though, is to find an easy way of accessing this kind of functionality. Enter the keypad.”
The manufacturer’s research and development team took a close look at how users interface with a drive. Based on that research, the company developed what it calls “the most user-friendly keypad ever.” There are eight soft keys, through which all parameters, functionality, and setups can be accessed.
The manufacturer is harmonizing the keypads of all of its drives. “A common look and feel allows users to switch between different ABB products easily, without having to go through a time-consuming learning process for each new product.”
THE MAGIC OF WIZARDSThe company also developed a series of “wizards” aimed at guiding the user through various procedures. There are maintenance assistants, diagnostic assistants, and, one of the most widely used, a startup assistant by which the user is guided through both startup and commissioning by asking questions in plain text language.
“There are no complex parameter numbers or codes,” the paper states. “The product’s intelligence helps the user through the commissioning process.”
Another device, called FlashDrop, can be used to select and set parameters, and copy configurations between drives, without powering up the drive. FlashDrop technology streamlines the drive configuration process, allowing users to download a set of parameters in seconds. “No specialized knowledge is required to use FlashDrop,” the company said. “The user interface will be familiar to users of ABB drives.”
APPLICATION-SPECIFIC SOLUTIONSCustomers have expressed a deep interest in total cost of ownership, such as commissioning, swap-outs, and maintenance. “AC drive users can now reduce costs even more by employing application-specific drive solutions,” the company said.
“These drives incorporate incremental functionality that supports specific applications such as fan and pump control, mixers, or crane controls. They can reduce the total cost of ownership through shorter startup times, lower integration costs, and improved machine productivity.”
Time savings during commissioning can range from one to several hours, the company said. For example, a new pump control software module, Intelligent Pump Control (IPC), is said to eliminate the need for an external programmable logic controller, and can help to save energy, reduce downtime, and prevent pump jamming and pipeline blocking.
The IPC contains all the common functions needed by water and waste utilities, industrial plants, and other pump users through six pump control functions.
The software also features an adaptive programming utility, which lets users customize drives for specific applications. “This utility consists of a set of simple-to-use blocks that can be programmed to perform any operation from a predefined set of functions,” the authors said. “All common mathematical and logical functions, as well as switches, comparators, filters, and timers, are available.”
The company cited one more breakthrough. Programming can be carried out using the standard control panel. As a result, the programming can be carried out onsite, during commissioning.
Publication date: 06/25/2007