Power-system protection
![A digital (numeric) multifunction protective relay for distribution networks. A single such device can replace many single-function electromechanical relays, and provides self-testing and communication functions.](/Images/godic/202501/09/Protective_relay4112.jpg")
Power-system protection is a branch of electrical power engineering that deals with the protection of electrical power systems from faults through the isolation of faulted parts from the rest of the electrical network. The objective of a protection scheme is to keep the power system stable by isolating only the components that are under fault, whilst leaving as much of the network as possible still in operation. Thus, protection schemes must apply with very pragmatic and pessimistic approach to clearing system faults. The devices that are used to protect the power systems from faults are called protection devices.