Fault analysis per unit, Representation and its advantages, Faults in power systems (Symmetrical and unsymmetrical), Single line and equivalent impedance diagram representation of power system components. Symmetrical components and its application to power systems, Fault analysis, Sequence networks and their interconnection for different types of faults, Effect of fault impedance, Current limiting reactors, Its location and application, Short circuit calculation.
Requirement of relays, Primary and backup protection, Desirable qualities of relays, Concept of pickup, Reset and drop-off, Drop off / Pickup ratio, Inverse time and definite time characteristics, Attracted armature, Balanced beam, Induction disc, Induction cup, Moving coil and moving iron, Rectifier, Thermal, Bimetal directional relay, Frequency, DC, All or nothing relays. Pilot and negative sequence, Over current, Over voltage, Directional, Differential and distance relays, R-X diagram, Impedance mho and reactance relay. Introduction of static analog and digital relays, Classification of static relays.
Elementary principle of arc quenching, Recovery and re-striking voltage, Arc quenching devices, Description and operation of bulk oil, Minimum oil, Air break, Air blast, , Vacuum circuit breakers and D.C. circuit breakers, Their comparative merits, LT switch gear, HRC fuses, Current limiting reactor and their design features, Influence of reactors in CB ratings, Testing of circuit breaker, Description of a simple testing station, Direct and indirect testing.
Protection of generators - Earth fault, Percentage, Differential, Loss of excitation, Prime mover failure, Over current, Turn to turn fault, Negative phase sequence, Heating, Reverse power protection schemes.
Protection of Transformers - Internal and external fault protection, Differential, Earth fault, Over current, Over heating, Protection schemes, Protection of transmission lines, Over current, Distance and carrier current protection schemes.
Surge Protection and Insulation Co-ordination
Switching surges, Phenomena of lightning, Over voltage due to lightning, Protection against lightning, Lightning arrestors, Selection of lightning arrestors, Surge absorbers and diverters, Rod gap, Horn gap expulsion type and valve type lightning arrestors, Solid resistance and reactance earthing, Arc suppression coil, Earthing transformers, Earthwires, Earthing of appliances, Insulation co-ordination, Definitions determination of line insulation, Insulation level of substation equipment, Co-ordination amongst items of substation equipment.