ELECTRICAL POWER SYSTEM NOTES

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