1.a) Give the comparison between various types of conductors used for transmission systems.
b) Calculate the loop inductance of a single phase line with two parallel conductors spaced 3.5m a part. The diameter of each conductor is 1.5cm. [15]
2.a) Explain the classification of transmission lines.
b) Explain why ABCD parameters are used for evaluating performance of a transmission line. [15]
3. Explain how long lines are represented by equivalent T model. [15]
4.a) Explain the terms attenuation, distortion, reflection and refraction coefficients w.r.t traveling waves.
b) Using Bewley’s Lattice diagram, represent the voltage and current waveforms of a short circuited line. [15]
5.a) Describe the phenomenon of corona occurring in transmission lines. How to reduce corona effect?
b) A 3φ equilaterally spaced transmission line has a total corona loss of kw at 110 kv and 110kw at 120kv. What is critical disruptive voltage between lines? What is the corona loss at 125 kv. [15]
6.a) By mean of an example show how grading of units is done for suspension insulators.
b) Explain about the properties that any insulating materials should posses. [15]
7.a) Explain what is the effect of wind and ice on weight of the conductor.
How are they accounted.?
b) For a overhead line span length is 185m, difference in levels of supports is 6.5m, conductor diameter 1.82cm, weight per unit length of conductor 1.5 kg and wind pressure of 39 kg/m2 of projected area. If the maximum tensile strength of the conductor is 4250 kg/cm2 and safety factor 5, calculate the sag. [15]
8.a) By mean of a diagram describe how inner sheath grading is provided in underground cables.
b) A cable has been insulated with two insulating materials having permittivity of 4 and 2.5 respectively. The inner and other diameters of the cable are 2.2cm and 7 cm. If the dielectric stress is 40 k v/ cm, calculate the radial thickness of each insulating layer and the safe working voltage of the cable. [15]
b) Calculate the loop inductance of a single phase line with two parallel conductors spaced 3.5m a part. The diameter of each conductor is 1.5cm. [15]
2.a) Explain the classification of transmission lines.
b) Explain why ABCD parameters are used for evaluating performance of a transmission line. [15]
3. Explain how long lines are represented by equivalent T model. [15]
4.a) Explain the terms attenuation, distortion, reflection and refraction coefficients w.r.t traveling waves.
b) Using Bewley’s Lattice diagram, represent the voltage and current waveforms of a short circuited line. [15]
5.a) Describe the phenomenon of corona occurring in transmission lines. How to reduce corona effect?
b) A 3φ equilaterally spaced transmission line has a total corona loss of kw at 110 kv and 110kw at 120kv. What is critical disruptive voltage between lines? What is the corona loss at 125 kv. [15]
6.a) By mean of an example show how grading of units is done for suspension insulators.
b) Explain about the properties that any insulating materials should posses. [15]
7.a) Explain what is the effect of wind and ice on weight of the conductor.
How are they accounted.?
b) For a overhead line span length is 185m, difference in levels of supports is 6.5m, conductor diameter 1.82cm, weight per unit length of conductor 1.5 kg and wind pressure of 39 kg/m2 of projected area. If the maximum tensile strength of the conductor is 4250 kg/cm2 and safety factor 5, calculate the sag. [15]
8.a) By mean of a diagram describe how inner sheath grading is provided in underground cables.
b) A cable has been insulated with two insulating materials having permittivity of 4 and 2.5 respectively. The inner and other diameters of the cable are 2.2cm and 7 cm. If the dielectric stress is 40 k v/ cm, calculate the radial thickness of each insulating layer and the safe working voltage of the cable. [15]
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