LFC: Two Area Control

Q. The main objectives of load frequency control in a power system are:
1. To bring the steady state error to zero after load change.
2. To maintain the net tie-line
3. To maintain voltage on all buses.
4. To economize the cost of generation

1. 1 and 2.
2. 2 and 3
3. 3 and 4
4. 1, 2, 3 and 4.

Q. Load frequency control uses

1. proportional controller alone
2. integral controller alone
3. both proportional and integral controllers
4. either proportional or integral controller

Q. The main objectives of load frequency controller are to apply control of
1. frequency
2. real power exchange via the outgoing lines
3. reactive power exchange via the outgoing lines
4. bus voltages

1. 1, 3 and 4
2. 1 and 3
3. 1 and 2
4. 2 and 4

Q. For a synchronous generator connected to an infinite bus through a transmission line, how are the change of voltage $\left(\Delta V\right)$ and the change of frequency $\left(\Delta f\right)$ related to the active power (P) and the reactive power (Q)?

1. $\left(\Delta V\right)$ is proportional to P and $\left(\Delta f\right)$ to Q.
2. $\left(\Delta V\right)$ is proportional to Q and $\left(\Delta f\right)$ to P.
3. Both $\left(\Delta V\right)$ and $\left(\Delta f\right)$ are proportional to P.
4. Both $\left(\Delta V\right)$ and $\left(\Delta f\right)$ are proportional to Q.

Q. Load frequency control is achieved by properly matching the individual machine's

1. reactive powers.
2. generated voltages.
3. turbine inputs.
4. turbine and generator ratings.

Q. A power system consists of $2$ areas (Area $1$ and Area $2$) connected by a single tie-line. It is required to carry out a load flow study on this system. While entering the network data, the tie-line data (connectively and parameters) is inadvertently left out. If the load flow program is run with this incomplete data.

1. The load flow will converge only if the slack bus is specified in area $1$
2. The load flow will converge only if the slack bus is specified in area $2$
3. The load flow will converge only if the slack bus is specified in either area $1$ or area $2$
4. The load flow will not converge if only one slack bus is specified.

Q. The speed of a 200 MW, 50 Hz alternator decreases by 4% from no load to full load. Its rated capacity is 200 MW. The speed regulation of alternator in Hz/MW will be

1. 0.43 Hz/MW
2. 0.65 Hz/MW
3. 0.01 Hz/MW
4. 0.25 Hz/MW

Q. In a turbine generator set $R=0.04p.u.$ based on the generator rating of 100 MVA and 60 Hz. The generator frequency decreases by 0.02 Hz and the system adjusts to steady-state operation. The turbine output power increases by

1. 1 MW
2. 1.2 MW
3. 0.83 MW
4. 0.63 MW

Q. Consider the following statements regarding load frequency control:
1. Time constant of automatic load frequency control is about 15 seconds.
2. Integral control eliminates static frequency drop.
3. In tie-line load bias control, the control signal for each area is proportional to change in frequency as well as change in tie-line power.

Which of the statements given above are correct?

1. 1, 2 and 3.
2. 1 and 2.
3. 1 and 3.
4. 2 and 3.