Substation Digital Equipment

Abstract

The majority of protection devices used in substations today are digital or numeric devices. Unlike older electromechanical devices that tended to only have one function, digital devices may have many functions, being able to perform several types of protection from the one device, including control functions, fault recording, and condition monitoring. Another benefit of these devices is that they can provide self-supervision and indication of failure should one occur, whereas many old electromechanical devices were unable to provide such indication and any failure would only be detected during maintenance or maloperation/non-operation during an actual fault. Digital devices tend to be smaller than their traditional counterparts, and their use means that fewer discrete relays are required, and hence less panel space, so the number of panels now required for a particular type of circuit is reduced. This mean that relay rooms may in turn be smaller, with consequential reductions in land and civil costs.