<b>Drives are now fully developed and are therefore more widely accepted as a product. They have become smaller, more capable, easier to use and cheaper, by orders of magnitude. The reductions in drive size by the use of integrated electronics have resulted from the use of fewer components, offering greater packing density, improvements in semiconductor technology and improved cooling techniques. An additional benefit of reducing the component count in a drive is that it cuts costs.
While air cooling is likely to remain the dominant technique, liquid cooling is finding increasing use in areas such as wind power, transportation and marine applications, as reflected by the recently launched, liquidcooled ABB industrial drive.
Increased functionality
These ever-shrinking drives contain ever-expanding functionality – thanks to developments in software. Today’s software monitors, diagnoses, configures and archives information and parameters concerning drives in industrial plants. ABB’s R&D team scrutinised every aspect of how a user interfaces with a drive and developed what it believes is the most user-friendly keypad ever. The keypad for the ABB standard drive features only eight soft keys, through which all parameters, functionality and set-ups can be accessed.
The true value of the keypad
The advantages are not all aesthetic. There is a real financial incentive for customers to choose this keypad and its intuitive commands. Most equipment investment decisions now carry a provision for fast installation to ensure that production will start rapidly and smoothly.
This can be achieved by eliminating manual intervention wherever possible; the keypad is central to this aim. These guiding principles, and the fact that there are only eight keys on the keypad, suggested the need for intuitive assistance. ABB 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 “start-up assistant”.
The magic of wizards
With the start-up assistant, ABB provides a tool that guides the user through both start-up and commissioning by asking questions in plain text language. There are no complex parameter numbers or codes. The product’s intelligence helps the user through the commissioning process.
Specialist HMI
Another tool that makes life easier for the OEM is a hand-held human-machine interface (HMI) that allows drive parameters to be installed in seconds. Called FlashDrop and available with selected ABB drives, the device can be used to select and set parameters, and to copy configurations between drives, without even powering up the drive.
Application-specific solutions
AC drive users can now reduce costs even more by employing application specific drive solutions. 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 start-up times, lower integration costs, and improved machine productivity.
Take, for example, ABB’s new pump control software module, Intelligent Pump Control (IPC), which eliminates the need for an external PLC (programmable logic controller) and can help to save energy, reduce downtime and prevent pump jamming and pipeline blocking. The IPC is a software add-on for ABB industrial drives. It 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 incorporates ABB’s adaptive programming utility, enabling users to customise 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. These days, users can have the power of a small PLC inside their drive in the form of ABB’s Adaptive Programming.
A further breakthrough is that programming can be carried out using the standard control panel. No special hardware or software programming tools are needed. As a result, the programming takes only a few minutes and can be carried out on-site, during commissioning.
Technology that stands the test of time
It is now 11 years since ABB launched its revolutionary motor control platform, Direct Torque Control (DTC). Now the algorthims have been tweaked in order to move standard AC drive technology into the servo arena. The result is the launch of the ABB machinery drive. The drive uses standard AC drive technology, but, by tuning DTC to include a motor model designed for servo motors, and by using very fast torque control loops within DTC – along with some other clever design work – the drive can now reach servo drive performance levels. It can control synchronous or asynchronous motors, either open- or closed-loop. With the new drive, depending on the application, machinery builders need specify only one drive for a variety of motor types along with an appropriate feedback device.
Three modules
Despite their significance, the advances described so far are only half the story. The ABB machinery drive features another significant major breakthrough aimed at meeting head-on the challenges faced by OEMs. This is the use of three plug-in modules that house the heart and brains of the drive. On the hardware side, there is a power module and a control interface module, while the software module provides easy programming of the relay logic or PLC routines that an OEM may require for its own applications. It is the way in which these modules are used that will reduce commissioning times, eliminate the need for external maintenance engineers and minimise unpredicted production line stoppages.
By providing separate units, both the power module and control interface can be shipped to site and installed ahead of the software memory unit. When the installation is complete, the memory unit, which can be programmed on the OEM’s own premises with specific application code, can be delivered and simply plugged into the control interface on site.
The modular approach also allows the number of product components and variants to be reduced. Since there is no need for on-site programming or the connection of any communication cables to PCs, time savings during commissioning can range from one to several hours.
The future
AC drives are set to be smaller, more intelligent, easier to install and control, have better communications, and be suitable for many more applications – particularly at the low power end of the range – all at a constantly reducing price. What better future could drive users ask for? ■
