Tag: power system protection

Overcurrent Relay

Overcurrent Relay: Overcurrent Relay – In a three phase system of relays, it is economical to build it on a single phase basis. Thus there will be three converter elements, one for each phase, but thereafter the rest of the circuits (e.g. measuring element, output element, etc.) will be common to all the three circuits. […]

Essential Qualities of Protection Systems

Essential Qualities of Protection Systems: Every Protection Systems which isolates a faulty element is required to satisfy four basic requirements: reliability; selectivity; fastness of operation; and discrimination. Without reliability and selectivity the protection would be rendered largely ineffective and could even become a liability. Reliability: Reliability is a qualitative term. Quantitatively it can be expressed […]

Zone Protection

Zone Protection: The Zone Protection is that part of a power system guarded by a certain protection and usually contains one or at the most two elements of the power system. The zones are arranged to overlap so that no part of the system remains unprotected. Figure (1.1) shows a typical arrangement of overlapping Zone […]