Power Systems-II

Conductor materials and types; resistance for solid conductors; Inductance for single-phase and three-phase single and double circuit lines; concept of GMR and GMD; Symmetrical and asymmetrical configuration with and without transposition; bundled conductors; skin and proximity effects; Capacitance for 2-wire and 3-wire systems; effect of ground; capacitance for symmetrical/asymmetrical single and double circuit lines

Classification: short, medium and long lines and their model representation; Nominal-T, nominal-pi and ABCD constants for symmetrical networks; Rigorous solution for long line equations; equivalent T and equivalent pi models; Surge impedance and surge impedance loading; regulation and efficiency; Ferranti effect

Types of system transients; propagation of surges; attenuation and distortion; Reflection and refraction coefficients; Termination of lines: open-circuited, short-circuited, through a resistance, connected to a cable; Reflection and refraction at a T-junction

Skin and proximity effects; Ferranti effect; Corona: description of the phenomenon, types of corona; Critical voltages and power loss; factors affecting corona; advantages and disadvantages; Radio interference

Sag and tension calculations with equal and unequal heights of towers; effect of wind and ice; Stringing chart and sag template and their applications; Types of insulators; voltage distribution in suspension insulators; String efficiency and methods for its improvement; capacitance grading and static shielding