Protection and Switchgear

Various faults and abnormal operating conditions, protection against unbalanced loading, over speeding, loss of excitation, loss of prime mover.

: Carrier aided protection of transmission lines, static comparators as relays, synthesis of various distance relays using static comparators, numerical protection.

Change of base, per unit quantities in three phase system, selection of base values, base quantities in terms of KV and MVA, per unit load impendence, advantages of per unit representation, one-line diagrams, preparation of impendence and reactance diagrams. Type of faults and their occurrence, symmetrical short circuit on the terminals of an unloaded generator, unsymmetrical faults on the terminals of an unloaded generator, faults on power system and their simulation

Abnormal operating conditions, protective system and its attributes, system transducer, various principles of power system protection.

Over current protection through fuse, thermal and over current relay, IDMT relay and application on distribution feeder, directional over current relays, differential and percentage differential protection, distance protection of transmission lines through impedance, reactance and mho relay, comparison between distance relays

Over current protection, percentage differential protection, incipient faults in transformers, inter-turn fault, protection against over fluxing. Differential protection of bus bars.

: Arc initiation and arc quenching theories, circuit breaker ratings, air circuit breaker, minimum oil circuit breaker, bulk oil circuit breaker, air blast circuit breaker, SF6 circuit breaker and vacuum circuit breaker.