Name of the College : Valliammai Engineering College
University : Anna University
Department : Electrical and Electronics Engineering
Subject Code/Name : PS7102-Power System Operation & Control
Degree : M.E Power Systems
Year : I
Semester : I
Document Type : Question Bank
Website : valliammai.co.in
Download :https://www.pdfquestion.in/uploads/va…%20Control.pdf
Power System Operation and Control
Unit I
Introduction
Part A :
1. Define spinning reserve.
2. What is meant by load frequency control?
3. What are the advantages of pool operation with respect to LFC?
4. What is the use of secondary loop in ALFC system?
Related : Valliammai Engineering College PS7103 Electrical Transients In Power System M.E Question Bank : www.pdfquestion.in/2800.html
5. Define connected load?
6. What is the role of computers in the operation and control of power system?
7. What is load curve?
8. What is base load?
9. Define load factor.
10. What is the need for load forecasting?
11. What is the need for voltage regulation in power systems?
12. Define diversity factor.
13. What is the effect of load factor on the cost of generation?
14. Define the term average load.
15. What is system level control
16. What are the effects of variable load in power system
17. What is the objective of power system control
18. What is the difference between load curve and load duration curve.
19. What are the different types of load
20. What is the significance of load factor and diversity factor.
Part B :
1. Define the following : (1) Hot reserve (2) Cold reserve (3) diversity factor
2. Explain the following : (i) Load forecasting (ii) Economic dispatch control.
3. (i) Explain the following terms : Installed reserve, spinning reserve, cold reserve, hot reserve.
(ii)A power station has to meet the following demand :
Group A :200KW between 8 A.M and 6 P.M
Group B :100KW between 6 A.M and 10 A.M
Group C :50KW between 6 A.M and 10 A.M
Group D :100KW between 10 A.M and 6 P.M and then between 6 P.M and 6 A.M. Plot the daily load curve and determine diversity factor, units generated per day and load factor.
4. (i)Discuss about the recent trends in real time control of power systems.
(ii) Write short notes on load forecasting.
5. i)What is meant by chronological load curve? Give the information obtained from load curves.
ii)Explain the advantages and different types of computer control system.
6. Describe briefly about plant level and system level control.
7. i) what are the information obtained from load curve and load duration curve?
ii) Briefly describe the importance of load forecasting and explain the method of least square fit forecasting the base load.
8. What are objectives of modern trend in real time control of power system? Explain the significant features of computer control in power system.
9. i) with neat sketch describe the p-f and Q-V control structure.
ii) Explain the following terms
i. Maximum Demand
ii. Plant use factor
iii. Plant capacity factor
iv. Reserve capacity
10. (i) Explain the need for voltage and frequency regulation in power system
(ii) A generating station has maximum demand of 400 MW. The annual load factor is 65% and capacity factor is 50% find the reserve capacity of the plant.
11. Draw load curve and load duration curve. Explain the importance of these curves in connection with economic operation of power system
12. A generating station has maximum demand of 20 MW, load factor is 60% and capacity factor is 50% find the reserve capacity of the plant, daily energy produced, maximum energy that could be produced daily if the plant were running all the time and maximum energy that could be produced if the plant when running(acc. To operating schedule) were fully loaded.
13. A generating station has a maximum demand of 50,000 KW.calculate the cost per unit generated from the following data.
Capital Cost = Rs95 x 10
Annual load factor = 40%
Annual cost of fuel and oil = Rs9 x 10
Taxes, wages and salaries etc.= Rs7.5 x 10
Interest and depreciation = 12%
Unit II
Real Power- Frequency Control
Part A :
1. State the advantages of state variable model.
2. What is AGC?
3. What are the conditions necessary for sharing load operating in parallel between the two synchronous machines?
4. Define area control error.
5. What are the classification of system load?
6. What is meant by load frequency control.
7. Why the frequency and voltage to be regulated in a power system?
8. Compare the functions of “speed Governor” and “ speed changer” in a speed governing systems of a turbine generator set.
9. What do you understand by coherent group of generators?
10. A speed governor system cannot completely eliminate frequency error caused by a step load change in power system. Justify this statement.
11. How is the real power in power system controlled?
12. What is meant by free governor operation?
13. What is the function of load frequency control on a power system?
14. Define speed droop.
15. Draw the dynamic responses of change in frequency for a step load change for single area system
16. What is the use of secondary loop in ALFC system?
17. What is meant AFRC
18. State whether changes in AVR loop will be reflected in ALFC loop.
19. List the advantages of multi area operation.
20. Explain the principle of tie line bias control.
Part B :
1. Two synchronous generators operating in parallel. Their capacities are 300MW and 400MW. The droop characteristics of their governors are 4% and 5% from no load to full load. Assuming that the generators are operating at 50HZ at no load , how would be a load of 600MW shared between them. What will be the system frequency at this load? Assume free governor action.
2. Develop the state variable model of a two area system and state the advantages of the model.
3. Draw the block diagram of uncontrolled two area load frequency control system and explain the salient features under static condition.
4. How is speed governor mechanism modeled? Explain its operations with the speed load characteristics.
5. Derive the transfer function model and draw the block diagram for single control area provided with governor system. From the transfer function derive the expression for steady state frequency error for a step load change.
6. What are the components of speed governor system of an alternator? Derive its transfer function with an aid of a block diagram.
7. Explain the dynamic response of single area load frequency control.
8. Two 1000KW alternators operate in parallel. The speed regulation of first alternator is 100% to 103% from full load to no load and that of other 100% to 105%. How will the two alternators share load of 1200KW and at what will one machine cease to supply any portion of the load.
9. For a system regulation =4Hz/p.u.MW,Kp=150 Tp=18sec,?P0
10. Derive the expression for steady state frequency change for single area system with the following cases. =0.01p.u.Find the dynamic response of uncontrolled case. Also derive the equation used.
(i)Changes in load with fixed speed
(ii)changes in speed with fixed demand
11. i) Determine the primary ALFC loop parameters for a control area having the following data.
Total rated area capacity Pr=2000MW.
Normal operating load Pd=1000MW.
Inertia constant H=5.0
Regulation R=2.40 Hz/pu MW (all area generators)
We shall assume that the load frequency dependency as linear meaning that the old load would increase 1% for 1% frequency increase.
ii) Highly brief the importance of regulating frequency and voltage of the power system.
12. Explain the static and dynamic characteristics of single area control system.