The electronics in today’s automated equipment and computer networks need a clean and dependable source of electrical power. Not only can power surges, sag, and interruptions cause automation to stop in midstream and ruin product, but they also can destroy the equipment and wipe out crucial data. To avoid these problems, many manufacturing companies are installing uninterruptible power supplies (UPSs). These industrial grade batteries provide a constant level of AC power through sags and brief losses of power.
An example is the 1609 family of UPSs from Milwaukee-based Rockwell Automation Inc. The units provide power long enough either to ride through short sags and interruptions or to shut down personal computers (PCs), programmable logic controllers (PLCs), data-logging human-machine interfaces (HMIs), and other control devices safely.
limitation of this technology, however, is that it tends to be
efficient at full load under certain conditions and inefficient at
normal operating loads and conditions. For this reason, manufacturers,
such as American Power Conversion Corp., based in West Kingston, R.I.,
have been investing in
the transistor technology in the inverters of its UPSs. “We have made dramatic technological advances in inverter design that improve the power quality and greatly improve the efficiency of our online UPSs at lower loads,” says Steven Carlini, APC’s director of product management for three-phase power products.
In addition to its work with batteries and back-up generators, APC is also developing a fuel cell for providing extended backup. “We incorporate a fuel cell as an option for a UPS to replace the battery for extended run,” says Carlini. The running time is limited by the available hydrogen supply, and the current rating is 10 kilowatt (kW), but that can be scaled up to 30 kW.
To see the main story this sidebar was taken from - "Riding Those Sags and Surges" - please visit www.automationworld.com/view-2827