Fault Current Flow Direction in Relay Protection

Fault currents ABF and DCF flow towards the bus for relays R2 and R5 and away from the bus for relays R3 and R4. All these relays are provided with a directional feature whereby they operate only for the direction for which they are meant to operate. Protection equipment has the basic role of detecting an electrical fault and disconnecting that part of the network in which the fault occurs limiting the size of the disconnected section as far as possible. Directional relays play a crucial role in the protection and control of power systems, ensuring the reliable and efficient operation of electrical networks. [pdf]