Distance Protection
General Information
- Description
This is a non-unit protection that can be applied to overhead lines and cables. Distance protection discriminates between faults occurring in different parts of the system by measurement of impedance and so requires to be connected to CTs and VTs associated with the protected circuit.
Where distance protections are installed at both ends of a protected line the relays can be interconnected by a suitable communications link to form a unit protection – a number of operating schemes can be implemented.