General layout of power system, Standard voltages for transmission, advantages of high voltage transmission. Transmission line efficiency and line drop. Feeders, distributors & service mains.
Types of supporting structures and line conductors used. Sag calculation- supports at same level and at different levels. Effect of wind and ice, Sag at erection, Stringing chart and sag templates. Line vibrators.
Introduction, materials used, types, potential distribution over a string of suspension insulators. String efficiency & methods of increasing strings efficiency, grading rings and arcing horns. Testing of insulators.
(A)CORONA- Phenomena, disruptive and visual critical voltages, corona power loss. Advantages and disadvantages of corona. 4 Hours (B)UNDERGROUND CABLES- Types, material used, insulation resistance, thermal rating of cables, charging current, grading of cables, capacitance grading & inter sheath grading, testing of cables. 6 Hours
calculation of inductance of single phase line, 3phase lines with equilateral spacing,unsymmetrical spacing, double circuit and transposed lines. Inductance of composite conductor lines.Capacitance- of single-phase line, 3phase lines with equilateral spacing, unsymmetrical spacing, double circuit and transposed lines. Capacitance of composite conductor lines.
Short transmission lines, medium transmission lines- nominal T, end condenser and π models, long transmission lines, ABCD constants of transmission lines, Ferranti effect, line regulation.
Requirements of power distribution, radial & ring main systems, ac and dc distribution:calculation for concentrated loads and uniform loading.