Continuous power

The best way to avoid any failure is to see it coming in time to take preventive steps. That is the job the digital static transfer switch (DSTS) fulfills perfectly in the data center. Developed 30 years ago by ABB Cyberex, the DSTS switches a load between a primary power source and a backup, such as a generator.

Using semiconductors, DSTS analyzes power quality and automatically switches to an alternative power source when it detects any degradation of the primary source’s quality. DSTS employs silicon-controlled rectifiers as high-speed, open-transition switching devices for delivering power. With digital signal processing hardware and ABB-patented software, the switch analyzes source waveforms in real time.

Two digital signal processors sample the power sources 10,000 times a second and, with unique algorithms, detect source disruptions and failures in less than 2 milliseconds. Consequently, switching time from the detection of an anomaly to completion of the transfer normally is just one-quarter of a voltage cycle, or 4 ms. The ABB DSTS enables 99.9999 percent availability.

With this ability to detect source disruptions and failures, the DSTS is key to data center design. In Tier III or Tier IV dual-corded (system-plus-system) designs, the DSTS can supply redundant power availability to both cords continuously.

The DSTS also can be applied upstream with two independent feeds from separate substations. At power entry points in data centers, the DSTS can furnish protection, switching power, speeds and distribution efficiencies that are superior to standard automatic transfer switches. The ABB DSTS is able to eliminate upstream power quality issues without causing a downstream disturbance. Replacing the automatic transfer switches or even UPS systems, the DSTS can offer better reliability with a dramatically reduced footprint, higher electrical efficiencies and lower overall cost.

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