Protection Relays are widely used in most systems or applications such as panel-built control systems to advanced interface systems. It will be able to detect faulty sections and cut them off from the rest of the system. Consider it as a switch as it can open and close circuits electromechanically and electronically.
Let’s take a power system as an example, the reliability of power is crucial in a power system, and it consists of generators, transformers, distribution circuits, and others. Power system failure must be detected and failed components have to be disconnected immediately in order to run smoothly without any interruption.
Therefore, protection relays are useful by determining the fault quickly to prevent interruption.