Line distance protection REL650

REL650 provides protection of power lines and cables with high sensitivity and low CT requirements. Measurements and setting of all six zones with several setting groups are realized completely independently from each other to ensure high flexibility. The distance protection function supports both quadrilateral and mho impedance characteristics, selected on a per zone basis. This enables coordination with existing distance protection schemes in any power network.

The distance protection is further enhanced with load encroachment adaptation, which reduces the risk of mal-operation due to high load. This is especially useful in sub-transmission networks where high line load needs to be allowed while high resistive faults need to be detected and cleared. The unique load current compensation in the first zone prevents unwanted trips during resistive faults and high power transfer on the line.