Technical Negative Sequence Relay Use Cases Negative sequence components can be used to overcome some particular use cases where ground (3I0 or 3V0) or phase currents are inadequate, like open phase detection, seeing through delta connections, or adding security to polarization.
Power Systems Current Transformers for Protective Relaying -- Saturation and Knee Point Explained A graphical explanation of magnetic saturation, knee point demonstration and voltage ratings of CTs
Power Systems Distribution Autotransformers for Intertie Use - Grounding, Tertiary, & Fault Analysis Protection considerations for connecting distribution voltage level power systems together with autotransformers