ELECTRICAL POWER SYSTEM

IN THIS APPLICATION HAS THE FOLLOWING TOPICS 1. PROTECTION - protective schemes (i)core balanced protective schemes. (ii) merz-price protective schemes. (iii) pilot (iv) pilot-less. - types of relay systems (i) permanent magnet moving coil. (i) balanced beam (ii) induction type carrying relay (iv) the distance relay (v)non-directional relay (vi)solid state relay. -types of unit protection (i)generator protection (ii) transformer protection (iii) feeder protection - non-unit protection (i)directional current protection (ii) distance protection (iii) gradient time protection 2.OVERHEAD LINE CONSTRUCTION - conductor/mechanical vibration (i) swinging (ii)dancing (iii) jumping (iv) high frequency vibration - sag and tension (i)ca-ternary method -corona phenomenon (i)disruptive (ii)visible (iii)critical (iv)power loss - operation of synchronous phase modifies (i)lagging and leading (ii)volt drop compensation 3. OVERHEAD LINE TRANSMISSION - classification of transmission lines (i)short, medium and long lines - causes of surges in transmission line (i)direct and indirect lighting stroke (ii)open circuited lines (iii)short circuited lines (iv)an arching ground faults --phenomenon surges explanation in transmission line (i)surge velocity (ii)surge impedance (iii)open circuited and short circuited lines --protection of transmission line against surges (i)overhead earth wire (ii)horn gaps (iii)silicon and zinc oxides surge diverts (iv)Peterson coil 4.UNSYMMETRICAL FAULTS --types of power line faults (i)single phase to ground fault (L - G) (ii)3-phase faults (L - L -L) (iii)double line to ground fault (L - L - G) --description of symmetrical components (i)positive, negative and zero sequence vector (ii)Impendence connection matrices for fault (iii)equivalent circuit for unsymmetrical fault --operation of equivalent circuit and phase sequence matrix 5. POWER SYSTEM STABILITY --synchronous generator stability (i)power transfer regulation (ii)derivation of equal area of criterion (iii)change of load (iv)change in transfer reluctance due to switches (v)change in transfer reactance due to faults --derivation of swing equation --swing cap --methods of improving both transients and steady state stability