Transmission and Distribution
Semester : IV
Course Code : 18EE43
CIE Marks : 40 SEE Marks : 60
Module – 1
Hand Written Notes
Module – 2
Hand Written Notes
Module – 3
Hand Written Notes
Module – 4
Hand Written Notes
Module – 5
Hand Written Notes
TRANSMISSION AND DISTRIBUTION
18EE43
SYLLABUS
Module-1
Module-1 Introduction to Power System: Structure of electric power system: generation, transmission and distribution. Advantages of higher voltage transmission: HVAC, EHVAC, UHVAC and HVDC. Interconnection. Feeders, distributors and service mains.
Overhead Transmission Lines: A brief introduction to types of supporting structures and line conductors-Conventional conductors; Aluminium Conductor steel reinforced (ACSR), All – aluminium alloy conductor (AAAC) and All –aluminium conductor (AAC). High-temperature conductors; Thermal resistant aluminium alloy (ATI), Super thermal resistant aluminium alloy (ZTAI), Gap type thermal resistant aluminium alloy conductor steel reinforced (GTACSR), Gap type super thermal resistant aluminium alloy conductor steel reinforced (GZTACSR). Bundle conductor and its advantages. Importance of sag, Sag calculation – support at same and different levels, the effect of wind and ice. Line vibration and vibration dampers. Overhead line protection against lightning; ground wires.
Overhead Line Insulators: A brief introduction to types of insulators, the material used- porcelain, toughened glass and polymer (composite). Potential distribution over a string of suspension insulators. String efficiency, Methods of increasing string efficiency. Arcing horns.
Module-2
Line Parameters: Introduction to line parameters- resistance, inductance and capacitance. Calculation of inductance of single-phase and three-phase lines with equilateral spacing, unsymmetrical spacing, double-circuit and transposed lines. The inductance of composite – conductors, geometric mean radius (GMR) and geometric mean distance (GMD). Advantages of a single circuit and double circuit lines. ). Calculation of capacitance of single-phase and three-phase lines with equilateral spacing, unsymmetrical spacing, double-circuit and transposed lines. The capacitance of composite – conductor, geometric mean radius (GMR) and geometric mean distance (GMD). Advantages of a single circuit and double circuit lines.
Module-3
Performance of Transmission Lines: Classification of lines – short, medium and long. Current and voltage relations, line regulation and Ferranti effect in short length lines, medium-length lines considering Nominal T and nominal circuits, and long lines considering hyperbolic form equations. Equivalent circuit of a long line. ABCD constants in all cases.
Module-4
Corona: Phenomena, disruptive and visual critical voltages, corona loss. Advantages and disadvantages of the corona. Methods of reducing corona.
Underground Cable: Types of cables, constructional features, insulation resistance, thermal rating, charging current, grading of cables – capacitance and inter-sheath. Dielectric loss. Comparison between ac and DC cables. Limitations of cables. Specification of power cables.
Module-5
Distribution: Primary AC distribution systems – Radial feeders, parallel feeders, loop feeders and interconnected network system. Secondary AC distribution systems – Three-phase 4 wire system and single phase 2 wire distribution, AC distributors with concentrated loads. Effect of disconnection of neutral in a 3 phase four wire system.
Reliability and Quality of Distribution System: Introduction, the definition of reliability, failure, probability concepts, limitation of distribution systems, power quality, Reliability aids.