Digital static transfer switch: UPS and downs

The digital static transfer switch (DSTS) enables electrical systems engineers to take the overall redundancy and reliability of carrier data centers one step further by promoting a dual independent power system or multiple independent power systems. DSTSes are high-speed, open-transition switches that can transfer electrical loads from one AC power source to another in a fraction of a single electrical cycle. The DSTS overcomes the fallibility of conventional electrical system design by using redundant power paths. In general, the protective capability of a static switch is maximized if it is applied closest to the load. Rack-mount deployment of DSTS is one significant application. In another application, switches can be placed at the power distribution unit's secondary side of the transformer. In another scenario, the DSTS is an active maintenance bypass for an uninterruptible power supply. In this application, the DSTS provides the benefits of the continuous-duty switch, transfers if the UPS bypass fuses clear, and provides backup to the UPS system controls.