Power System Stability Objective Questions 2

1. The Critical Clearance time of a fault in the power system is related to
a) Reactive power limit
b) Short Circuit limit
c) Steady state stability limit
d) Transient stability limit

D

2. The equal area criteria of stability is used for:
a) no load on the busbar
b) One machine and infinite busbar
c) More than one machine and infinite busbar
d) None of the above

B

3. If the torque angle of the alternator increases indefinitely the system will show:
a) Steady state stability limit
b) Transient state stability limit
c) Instability
d) None of the above

C

4. The steady state stability of the power system can be improved by:
a) Increasing the number of parallel lines between the transmission points
b) Connecting capacitors in series with the line
c) Reducing the excitation of the machines
d) Both a and b

D

5. The transient stability limit of the power system can be increased by introducing:
a) Series Inductance
b) Shunt Inductance
c) Series Capacitance
d) Shunt Capacitance

C

6. The use of high speed breakers can:
a) Increase the transient stability
b) Decrease the transient stability
c) Increase the steady state stability
d) Decrease the steady state stability

A

7. The inertia constant of the two machines which are not swinging together are M1 and M2. The equivalent inertia constant of the system is:
a) M1-M2
b) M1+M2
c) M1M2/(M1+M2)
d) M1M2/(M1-M2)

A

8. If a generator of 250MVA rating has an inertia constant of 6MJ/MVA, its inertia constant on a 100MVA base is:
a) 15 MJ/MVA
b) 10.5 MJ/MVA
c) 6 MJ/MVA
d) 2,4 MJ/MVA

A