Unit 1 Electrostatic fields and field stress control

• Electrical field distribution and breakdown strength of insulating materials - fields in homogeneous
• isotropic materials - fields in multi-dielectric
• isotropic materials

Unit 2 Numerical analysis of electrical fields in high voltage equipment

4 lecture hours

• numerical methods - Charge simulation method (CSM)
• Finite Difference Method (FDM)
• Finite Element Method (FEM)
• The boundary-element method
• Comparative summary
• Formulation of the finite-element equations in two and three dimensions - Forming the functional equation
• The energy functional illustrated
• Numerical representation

Unit 3 Electrical breakdown in gases

5 lecture hours

• Gases as insulating media - ionization and decay processes
• Townsend first ionization coefficient
• photo ionization
• ionization by interaction of metastable with atoms
• thermal ionization
• deionization by recombination
• deionization by attachment–negative ion formation
• examples - cathode processes – secondary effects
• photoelectric emission
• electron emission by positive ion and excited atom impact
• thermionic emission
• field emission
• Townsend second ionization coefficient
• secondary electron emission by photon impact
• examples - transition from non-self-sustained discharges to breakdown
• the Townsend mechanism
• examples - the streamer or ‘kanal’ mechanism of spark
• examples - the sparking voltage– Paschen’s law, penning effect

Unit 4 Breakdown in liquid and solid dielectrics

• Liquid as insulators
• breakdown in liquids - electronic breakdown
• suspended solid particle mechanism
• cavity breakdown
• examples - static electrification in power transformers
• 07 Subject Code: 3170917 w.e.f
• AY 2018-19 transformer oil filtration
• transformer oil test
• alternative liquid insulations like vegetable oils
• esters and silicon oils - breakdown in solids
• intrinsic breakdown
• streamer breakdown
• electromechanical breakdown
• edge breakdown and treeing
• thermal breakdown
• erosion breakdown
• tracking - breakdown of solid dielectrics in practice
• partial discharges in solid insulation

Unit 5 Generation of high voltages

7 lecture hours

• Generation of high direct voltages
• half and full wave rectifier circuits
• voltage multiplier circuits
• Van de Graff generators
• electrostatic generators
• examples - generation of alternating voltages
• testing transformers
• cascaded transformers
• resonant transformers
• examples - impulse voltages
• Standard lightning and switching surge and associated parameters and their corrections
• design and construction of impulse voltage generator circuits
• Marx circuit
• examples - impulse current generator

Unit 6 Measurement of high voltages

6 lecture hours

• High direct voltage measurement
• peak voltage measurements by spark gaps
• sphere gaps
• reference measuring systems
• uniform field gaps
• rod gaps
• factors affecting sphere gap measurements
• examples - electrostatic voltmeters - ammeter in series with high ohmic resistors and high ohmic resistor voltage dividers - generating voltmeters and field sensors - the measurement of peak voltages
• the Chubb–Fortescue method
• high- voltage capacitors for measuring circuits - voltage dividing systems and impulse voltage measurements

Unit 7 Over voltages, and insulation coordination

4 lecture hours

• The lightning mechanism
• energy in lightning
• nature of danger - examples - insulation coordination
• insulation level
• statistical approach to insulation coordination
• correlation between insulation and protection levels

Unit 8 Non-destructive test techniques

5 lecture hours

• Insulation Measurement of d.c. resistivity - dielectric loss and capacitance measurements
• the Schering bridge
• current comparator bridges
• Tan Delta measurement
• Partial-discharge (PD) measurements - the basic PD test circuit
• Dissolved gas analysis - Key gas method
• Duval's triangle
• Machine winding: Frequency Response Analysis Method (FRA)- Introduction
• Sweep Frequency Response Analysis (SFRA)
• methods of interpretation of signature

Unit 9 High voltage testing

• Testing of insulators and bushings
• testing of isolators and circuit breakers Testing of cables
• testing of transformers - testing of surge diverters 05 Note: 1. 10%-20% weightage should be given to the Examples and Short/Multiple choice questions. 2
• The institutes which does not have proper High Voltage Laboratory are advised to visit nearby High Voltage laboratory Subject Code: 3170917 w.e.f