PSA 1

Power system analysis 1 Get IOE ALL Subject notes and Important Questions

psa

• Chapter 1 Questions:

1. What do you mean by interconnected power system? Draw a typical diagram of inter connected power system. What are its advantage over isolated power system.
2. Explain how electrical energy can be generated from hydropower plant with basic block diagram.
3. Draw a single line diagram showing generation, transmission and distribution components of power system with typical voltage levels and discuss why different voltage are used in these three components of power system. Also explain why transmission and distribution system are three phase ac system instead of single phase ac system.
4. What happen if long line is modelled by short line model and vice versa?
5. Describe the concept of infinite bus in electric power system. Discuss how the national electric grid of any country can be considered as infinite bus.
6. What are conventional sources of energy? List out some features of the power generating stations using conventional energy sources.
7. List out the major component used in electric power station. Describe the function of any four major components.
8. Why AC power generation, transmission an distribution prevailed over DC system in early both century?
9. Explain the evolution of power system and mention its major milestones.
10. Compare the economical aspects of 1-ø and 3-ø power delivery system. Give the suitable mathematical relationship to justify the argument
11.  Discuss the different types of renewable energy sources.
12. Describe in brief hydro and thermal power sources with basic principle of electricity generation and major features.
13. What are the major sources of Electricity worldwide? Give reason why existing electricity supply scenario is not sustainable.
14. Compare the advantage and disadvantages associated with fossil fuel based energy and renewable energy systems.

• Chapter 2

1. Explain one of the technique to locate the phase to phase fault on underground power cable.
2. Prove that dielectric stress is maximum at the conductor surface and its value goes on decreasing as we move away from the conductor.
3. What do you mean by stranded and bundled conductor in power transmission system. Explain the reason of using bundled conductors in Extra high voltage (EHV) transmission lines. 
4. Classify power cables and give reasons for their usage. Briefly discuss about installation techniques.
5. Describe Murray Loop test method for underground cable fault detection.
6. What are the reasons for making stranded and bundled conductors for transmission line? 
7. Mention the main requirements of conductors for overhead transmission lines. 
8. Compare overhead lines with underground cables. 
9. Give the reason for the extensive use of aluminum conductors in overhead transmission lines. 
10. For an insulator string consisting of multiple disc insulators, show that the voltage distribution across each disc is not same
11. What is power cable? Explain briefly.

• Chapter 3  

1. What is per unit system ? What are the advantages of per unit representation?
2. Define complex power and explain the sign conventions of power for sources and loads.
3. Derive the expression for sending end voltage (Vs) in terms of receiving end voltage (Vr) , line resistance (R) and reactance (X) and complex power (P+jQ) demand at the receiving end and hence justify that reactive power always flows from higher voltage magnitude to lower voltage magnitude.
4. How are the base voltage and base power are chosen?
5. Why complex power is taken VI* rather than V*I in power system, explain?
6. Starting from voltage and current phasors, derive the expression for complex power. Construct the phasor diagram of complex power and explain the significance of those components.

• Chapter 4

1. Explain skin and proximity effect in the transmission line.
2. Derive the expression for the inductance per meter of a single phase two wire transmission line.
3. What is the importance of the transposition of high voltage transmission lines? Draw the schematic layout for the complete transpositon cycle for 3-ø single circuit and 3-ø double circuit transmission line.
4. Derive the line capacitance and phase capacitance of the single phase line considering the effect of the ground. 
5. What is the effect of earth on the capacitance of an overhead line? Explain with mathmatical expression(derivation not required).
6. Show that the inductance due to internal flux linkage of two conductors of different diameters are same.
7. Derive the expression for inductance of transposed three phase line with unsymmetrical spacing. 

• NUMERICAL: (Compulsary) 

1. Voltage and string efficiency of Discs

• Without grading ring 
• With grading ring

1.  Diectric stress (find gmax,gmin,thickness of insulation)
2. Capacitance of cable
3. Resistance of cable
4. Resistance of cable
5. Reactance diagram
6. Inductance,GMD,GMR

• Internal and external flux linkage 
• Internal and external flux linkage 
• Three phase line:

1. Equilateral 
2. Equilateral