Anna University , Chennai
Department of B.E-Electrical and Electronics Engg
Sixth Semester
EE2353 High Voltage Engineering
Handwritten Scanned Lecture Notes - Niranjan Kumar Edition
(Regulation 2008)
Attachment : Click HereContent :
HIGH VOLTAGE ENGINEERING
UNIT-1
OVER VOLTAGES IN ELECTRICAL POWER SYSTEM
Introduction
Application of high voltages
Structure of power station
Components of electrical power system
1. Generator
2. Transformer
3. Transmission line
Need for EHV transmission
Advantages
Limitation
Internal over voltages
Charge formation in the cloud
Simpson’s theory
Reynold and mason theory
Mechanism of lightings
Switching surges and temporary over voltages
Source of switching surges
Characteristics of switching surges
Shunt reactor
Causes for power frequency over voltages
Sudden load rejection
Ferranti effects
Unsymmentrical faults
Saturation of transformer
Tap changing operation
Protection against over voltages
Types of faults
Ground wire
Valve type lighting arrester
UNIT-2
ELECTRICAL BREAKDOWN IN GASES, SOILDS AND LIQUIDS
Gaseous breakdown
Insulating materials
Discharge in gas
Townsend’s first ionization co-efficient
Streamer mechanism
Meek’s expression
Paschen’s law
Corona inception field
Formation of negative corona
Positive plane corona
Formation of streamer
Breakdown in non-uniform fields
Vaccum breakdown
Classification of vaccum
Breakdown process in vaccum
Particle exchange mechanism
Field emission theory
Clump mechanism
Use of liquid dielectrics
Classification
1. Transformer oil
2. Synthetic hydrocarbons
3. Chlorination hydro carbons
4. Silicon oils
5. Esters
6. Latest developments
Characteristics of liquid dielectrics
Electrical properties
1. Permittivity
2. Resistivity
3. Power factor
4. Dielectric strength
Heat transfer characteristics
Chemical stability
Pure liquids
Commercial liquids
1. Purification
2. Breakdown tests
Electronic breakdown
Breakdown mechanism
Classification of BD in commercial liquids
1. Suspended particle mechanism
2. Cavitation and bubble mechanism
3. Thermal mechanism
4. Stressed oil volume mechanism
Breakdown in solid dielectrics
Properties of solid dielectrics
Intrinsic breakdown
Breakdown mechanism
Electronic breakdown
Avalanche breakdown
Electromechanical breakdown
Thermal breakdown
Oxidation
Hydrolysis
Chemical action
Tracking
Two types of breakdown mechanism
1. Short term breakdown
2. Long term breakdown
UNIT-3
GENERATION OF HIGH VOLTAGE AND CURRENTS
High voltage transmission
Advantages
Disadvantages
Application
Generation of high direct current DC voltages
Half wave and full wave rectifier
Voltage doubler circuits
Cascaded voltages doubler circuits
Electrostatic machines
Van de groff generation
Principle
Electrostatic generation
Cascaded transformer
Resonant transformer
Analysis of output waveform
Generation of impulse voltages
Wave shape control
Multistage impulse generation
Generation of switching surges
Production of switching surges
UNIT-4
MEASUREMENTS OF HIGH VOLTAGES AND HIGH CURRENTS
Measurements of high DC voltages
Resistance potential divides for DC voltages
Generating voltmeter
Principle of operation
Measurements of high AC voltages
Series impedance voltmeter
Series capacitance voltmeter
Capacitance potential divider
Electrostatic voltmeter
Peak reading AC voltmeter
Types
1. Series capacitor peak voltmeter
2. Digital peak voltmeter
3. Peak voltmeter with potential divider
Modified peak voltmeter
Sphere gap measurement
Sphere gap construction
Uniform field electrodes , gaps
Rod gaps
Capacitance voltages divides
Peak reading voltmeter for impulse voltages
Measurements of high DC , AC and impulse currents
Solved problems
UNIT-5
HIGH VOLTAGE TESTING AND INSULATION CO-ORDINATION
Testing with power frequency voltages
Testing with lighting impulse voltages
Testing with switching impulse
DC voltages
1. Type test
2. Routine test
Testing of insulation
Surge arresters
1. Spark gap
2. The non-linear resistor diodes
Types
1. Rod arrester
2. Horn gap arresters
3. Multi gap arrester
4. Expulsion arrester
5. Valve type arrester
Testing of surge arresters
Testing of transformer
1. Partial discharge test
Impulse testing of transformer
Testing of cables
Preparation of the cables samples
Testing of isolation and circuit breakers
Direct testing
Synthetic testing
Composite testing
Unit testing
Testing of bushing
Test on bushing
1. Power factor test
2. Partial discharge test
3. One minute wet withstand test
4. Impulse withstand test
5. Chopped wave and switching surge test
6. Temperature rise test
7. Thermal stability test
Insulation co-ordination
Basic requirements
Basic impulse insulation level
Withstand voltages
Critical flash over voltages
Selection of surge divider
Separation limit for lighting arrester
Insulation coordination of substation
Direct strokes and back flash over
Equipment insulation level
Indian and international standard specification
Attachment : Click Here
UNIT-1
OVER VOLTAGES IN ELECTRICAL POWER SYSTEM
Introduction
Application of high voltages
Structure of power station
Components of electrical power system
1. Generator
2. Transformer
3. Transmission line
Need for EHV transmission
Advantages
Limitation
Internal over voltages
Charge formation in the cloud
Simpson’s theory
Reynold and mason theory
Mechanism of lightings
Switching surges and temporary over voltages
Source of switching surges
Characteristics of switching surges
Shunt reactor
Causes for power frequency over voltages
Sudden load rejection
Ferranti effects
Unsymmentrical faults
Saturation of transformer
Tap changing operation
Protection against over voltages
Types of faults
Ground wire
Valve type lighting arrester
UNIT-2
ELECTRICAL BREAKDOWN IN GASES, SOILDS AND LIQUIDS
Gaseous breakdown
Insulating materials
Discharge in gas
Townsend’s first ionization co-efficient
Streamer mechanism
Meek’s expression
Paschen’s law
Corona inception field
Formation of negative corona
Positive plane corona
Formation of streamer
Breakdown in non-uniform fields
Vaccum breakdown
Classification of vaccum
Breakdown process in vaccum
Particle exchange mechanism
Field emission theory
Clump mechanism
Use of liquid dielectrics
Classification
1. Transformer oil
2. Synthetic hydrocarbons
3. Chlorination hydro carbons
4. Silicon oils
5. Esters
6. Latest developments
Characteristics of liquid dielectrics
Electrical properties
1. Permittivity
2. Resistivity
3. Power factor
4. Dielectric strength
Heat transfer characteristics
Chemical stability
Pure liquids
Commercial liquids
1. Purification
2. Breakdown tests
Electronic breakdown
Breakdown mechanism
Classification of BD in commercial liquids
1. Suspended particle mechanism
2. Cavitation and bubble mechanism
3. Thermal mechanism
4. Stressed oil volume mechanism
Breakdown in solid dielectrics
Properties of solid dielectrics
Intrinsic breakdown
Breakdown mechanism
Electronic breakdown
Avalanche breakdown
Electromechanical breakdown
Thermal breakdown
Oxidation
Hydrolysis
Chemical action
Tracking
Two types of breakdown mechanism
1. Short term breakdown
2. Long term breakdown
UNIT-3
GENERATION OF HIGH VOLTAGE AND CURRENTS
High voltage transmission
Advantages
Disadvantages
Application
Generation of high direct current DC voltages
Half wave and full wave rectifier
Voltage doubler circuits
Cascaded voltages doubler circuits
Electrostatic machines
Van de groff generation
Principle
Electrostatic generation
Cascaded transformer
Resonant transformer
Analysis of output waveform
Generation of impulse voltages
Wave shape control
Multistage impulse generation
Generation of switching surges
Production of switching surges
UNIT-4
MEASUREMENTS OF HIGH VOLTAGES AND HIGH CURRENTS
Measurements of high DC voltages
Resistance potential divides for DC voltages
Generating voltmeter
Principle of operation
Measurements of high AC voltages
Series impedance voltmeter
Series capacitance voltmeter
Capacitance potential divider
Electrostatic voltmeter
Peak reading AC voltmeter
Types
1. Series capacitor peak voltmeter
2. Digital peak voltmeter
3. Peak voltmeter with potential divider
Modified peak voltmeter
Sphere gap measurement
Sphere gap construction
Uniform field electrodes , gaps
Rod gaps
Capacitance voltages divides
Peak reading voltmeter for impulse voltages
Measurements of high DC , AC and impulse currents
Solved problems
UNIT-5
HIGH VOLTAGE TESTING AND INSULATION CO-ORDINATION
Testing with power frequency voltages
Testing with lighting impulse voltages
Testing with switching impulse
DC voltages
1. Type test
2. Routine test
Testing of insulation
Surge arresters
1. Spark gap
2. The non-linear resistor diodes
Types
1. Rod arrester
2. Horn gap arresters
3. Multi gap arrester
4. Expulsion arrester
5. Valve type arrester
Testing of surge arresters
Testing of transformer
1. Partial discharge test
Impulse testing of transformer
Testing of cables
Preparation of the cables samples
Testing of isolation and circuit breakers
Direct testing
Synthetic testing
Composite testing
Unit testing
Testing of bushing
Test on bushing
1. Power factor test
2. Partial discharge test
3. One minute wet withstand test
4. Impulse withstand test
5. Chopped wave and switching surge test
6. Temperature rise test
7. Thermal stability test
Insulation co-ordination
Basic requirements
Basic impulse insulation level
Withstand voltages
Critical flash over voltages
Selection of surge divider
Separation limit for lighting arrester
Insulation coordination of substation
Direct strokes and back flash over
Equipment insulation level
Indian and international standard specification
Attachment : Click Here
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