Power System

Basic structure of power system, sources of electric energy: conventional and non-conventional; cogeneration, combined heat and power, captive power plants, distributed generation. Commonly used terms and factors, curves useful in system operation and planning, economics of power factor improvement, interconnection of power stations and tariffs.

Types of conductors, Ampere’s law, inductance of a conductor, inductance of a single phase line, inductance of a three-phase line, inductance of three-phase double circuit line, bundled conductors, skin effect , proximity effect, Guy’s theorem, Capacitance of single phase line, capacitance of a three-phase line, capacitance of double circuit three phase line, effect of earth on capacitance

Classification of lines, models, circuit constants of transmission lines: short, medium and long lines; Ferranti effect, power flow through a line, sending and receiving end power circle diagram, reactive power generation/absorption of line, compensation and voltage control.

Types of insulators, ratings, voltage distribution across suspension insulators, string efficiency, methods to improve string efficiency. Calculation of sag and tension, equivalent span length and sag, effect of ice and wind loading, stringing chart, sag template, conductor vibrations and vibration dampers

Critical voltages, corona loss, advantages and disadvantages of corona, factors affecting corona loss, effect of corona on line design, radio interference.

Effect of voltage on transmission efficiency, Kelvin’s law, radial and ring main distributors, interconnectors, methods of feeding distributors, ac distribution, three-phase, four wire distribution system, stepped and tapered mains. Cable conductors, insulating materials, insulation resistance, electrostatic stress in cables, grading of cables, capacitance of a three-core cable, dielectric loss, dielectric power factor, classification of cables, cable performance.