Protection relays safeguard generators by preventing damage and ensuring grid stability through reverse power, loss of excitation, unbalanced load, thermal, overcurrent, earth fault, voltage/frequency, and over-fluxing protections.

Differential protection detects faults by comparing input and output currents of equipment; imbalance triggers a trip signal to isolate the fault. It offers high sensitivity and selectivity.

Symmetrical components analyze unbalanced three-phase systems: positive sequence (balanced, normal operation), negative sequence (balanced but reverse rotation, causes motor heating), and zero sequence (in-phase, linked to earth faults).

VTs use electromagnetic induction for voltage measurement, suited for systems up to 132 kV. CVTs combine capacitive division with electromagnetic transformation, offering higher stability and accuracy, ideal for high-voltage applications.