Performance of Long Transmission Lines Interview Questions:
Following are the below Performance of Long Transmission Lines Interview Questions and Important Questions which is very useful for interviews and exams
1. Derive the expression for sending-end voltage and current in terms of receiving-end voltage and current for long transmission lines. What do you understand by the “characteristic impedance” and “propagation constant” in it.
2. Using rigorous method derive expressions for sending-end voltage and current for long transmission line.
3. Starting from fundamentals, derive the equations for sending-end voltage and sending-end current for a long transmission line. Use the distributed parameter form of representation of the long line. Obtain the A, B, C, D parameters of the line.
4. Using the distributed parameter form of transmission line model, obtain the equations for Vs and Is in terms of VR, IR, line resistance per km, r, line inductance per km, l, conductance per km, g, capacitance per km, c, propagation constant, gamma γ and characteristic impedance ZC.
5. Derive the A, B, C, D constants of a long transmission line from the basic principle.
6. What do you understand by the generalised constants of a transmission line ? What is their significance ?
7. Define the generalised A, B, C, D constants of a transmission line and determine their values for a long transmission line. Hence show A = D and AD – BC = 1.
8. Starting from first principles deduce expressions for ABCD constants of a long line in terms of its parameters. Define propagation constant and characteristic impedance.
9. Develop the long line exact equations in hyperbolic terms for sending-end voltage and current.
10. With reference to long transmission lines, give physical interpretation of the terms ‘characteristic empedance’ and ‘propagation constant.’ What is meant by surge impedance ?
11. Explain surge impedance loading of a transmission line.
12. Explain briefly about “SIL”.
13. Obtain equivalent-Ï€ model of a long transmission line.
14. Explain the concept of regulation in long transmission line. If regulation is very high then what can be seen adversely in power network.
15. What are A, B, C and D constants of a long transmission line and derive these constants for nominal T and π-network of a long transmission line.
16. Discuss the equivalent ‘T’ circuit for long length line.
17. A long transmission line is open circuited at the receiving end. Will there be any current in the line at the sending end ? Explain your answer.
18. Explain the function of a synchronous phase modifier placed at the receiving end of the transmission line.
19. Explain the synchronous phase modifiers with their ratings in detail.
20. Discuss the action of a synchronous phase modifier for voltage regulation of a line and explain how its use increases the carrying capacity of a transmission line.
21. Assume that the equations between the sending-end voltage and current with the corresponding receiving-end voltage and current in terms of A, B, C, D constants of a long transmission line are known, derive equations for sending-end and receiving-end power.
22. What are power circle diagrams ? How are they useful ? Show how receiving-end power diagram may be drawn for a transmission line.
23. Explain under what conditions, the locus of receiving-end complex power would be a circle. Obtain the expression for the radii and cordinates of the centre of circle.
24. Show how receiving-end power circle diagram of a transmission line based on generalized (A, B, C, D) constants can he drawn.
25. Show how sending-end power circle diagram of a transmission line based on generalized (A, B, C, D) constants can be drawn.
26. What is a universal power circle diagram of a transmission line ? Explain how it can be constructed and what useful informations can be obtained from it.
27. Write short notes on the following :
- Rigorous method of solution for a long transmission line.
- Surge impedance of a transmission line.
- Tuned power lines.
- Synchronous phase modifiers.
- Power circle diagram of a transmission line.
- Power circle diagram.
- Universal power circle diagram.