6EE2 HIGH VOLTAGE ENGINEERING

Unit-1

(i) Breakdown in Gases:

Introduction to mechanism of breakdown in gases, Townsend’s

breakdown mechanism. Breakdown in electromagnetic gases. Application of gases in power

system.

(ii) Breakdown in Liquids:

Introduction to mechanism of breakdown in liquids, suspended

solid particle mechanism and cavity breakdown. Application of oil in power apparatus.

(iii) Breakdown in solids:

Introduction to mechanism of breakdown in solids,

electromechanical breakdown, treeing & tracking breakdown and thermal breakdown.

Unit-2

(i) High DC Voltage Generation:

Generation of high dc voltage, basic voltage multiplier

circuit.

(ii) High AC Voltage Generation:

Cascaded Transformers.

(iii) Impulse Voltage generation:

Impulse voltage, basic impulse circuit, Mark’s multistage

impulse generator.

(iv) Measurement of High Voltage:

Potential dividers - resistive, capacitive and mixed

potential dividers. Sphere gap- Construction and operation. Klydonorgraph.

Unit-3

Nondestructive Insulation Tests:  (i)

Measurement of resistively, dielectric constant and loss

factor.  High Voltage Schering Bridge- measurement of capacitance and dielectric loss.

(ii) Partial Discharges:

Introduction to partial discharge, partial discharge equivalent circuit.

Basic wide-band and narrow band PD detection circuits.

Unit-4

(i) Over voltages:

Causes of over voltages, introduction to lightning phenomena, over

voltages due to lighting.

(ii) Travelling Waves:

Travelling waves on transmission lines-open end line, short circuited

line, line terminated through a resistance, line connected to a cable, reflection and refraction at

a T-junction and line terminated through a capacitance. Attenuation of tavelling waves.

Unit-5

(i) Over Voltage Protection:

Basic

construction and operation of

ground wires- protection

angle and protective zone, ground rods, counterpoise, surge absorber, rod gap and arcing horn,

lighting arresters - expulsion type, non -linear gap type and metal oxide gapless type.