Phase distance relays are commonly applied on the low voltage side of a transformer to protect higher voltage lines The Compensator Distance Element Principle is a supe-
rior design for accurately applying distance relays through transformers. It is unaffected by common delta wye transformer connections and basically measures positive-sequence impedance Compensator Distance Elements can be affected by load,
causing the relay to over- or underreach Phase-pair distance relay designs can be applied, but relay reaches must be analyzed when reaching through transformer banks.
Power Directional RelayPower Directional Relay2
