5EE5-TRANSMISSION & DISTRIBUTION OF ELECTRICAL POWER |
Units: I |
(i) Supply systems: - Basic network of power system. Transmission and distribution voltage,
effect of system voltage on size of conductor and losses. Comparison of DC 2- wire, DC 3-
wire, 1- phase AC and 3- phase AC (3- wire and 4- wire) systems. (ii) Distribution Systems: -
Primary and secondary distribution systems, feeder, distributor and service mains. Radial and
ring- main distribution systems. Kelvin’s law for conductor size.
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Units: II-Mechanical features of overhead lines: |
Conductor material and types of conductor.
Conductor arrangements and spacing. Calculation of sag and tension, supports at different
levels, effect of wind and ice loading, stringing chart and sag template. Conductor vibrations
and vibration dampers. |
Units: III-Parameters of Transmission Lines: |
Resistance inductance and capacitance of overhead lines,
effect of earth, line transposition. Geometric mean radius and distance. Inductance and
capacitance of line with symmetrical and unsymmetrical spacing Inductance and capacitance
of double circuit lines. Skin and proximity effects.
Equivalent circuits and performance of short and medium transmission lines.
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Units: IV |
(i)Generalized ABCD line constants, equivalent circuit and performance of long transmission
line. Ferranti effect. Interference with communication circuits. Power flow through a
transmission line (ii) Corona: Electric stress between parallel conductors. Disruptive critical
voltage and visual critical voltage, Factors affecting corona. Corona power loss. Effects of
corona.
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Units: V |
(i) Insulators: Pin, shackle, suspension, post and strain insulators. Voltage distribution across
an insulator string, grading and methods of improving string efficiency. (ii) Underground
Cables: Conductor, insulator, sheathing and armoring materials. Types of cables. Insulator
resistance and capacitance calculation. Electrostatic stresses and reduction of maximum
stresses. Causes of breakdown. Thermal rating of cable. Introduction to oil filled and gas filled
cables.
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