Protection & Switchgear Premium Lecture Notes (All Units) - Sree Kala Edition

Protection & Switchgear Premium Lecture Notes prepared by Sree Kala Edition. Specially for B.E Electrical and Electronics Engineering. Syllabus is based on Anna University , B.E Electrical and Electronics Engineering R2008 Regulation.

Syllabus :

UNIT-1 (pg.no 1-56) : INTRODUCTION
UNIT-2 (pg.no 57-102) : OPERATING PRINCIPLE AND RELAY CHARACTERISTICS
UNIT-3 (pg.no 103-158) : APPARATUS PROTECTION
UNIT-4 (pg.no 160-178) : THEORY OF CIRCUIT INTERRUPTION
UNIT-5 (pg.no 180-204) : CIRCUIT BREAKER

Content :

UNIT-1
INTRODUCTION

• Qualities of protective relaying
• Reliability
• Selectivity and discrimination
• Speed and time
• Sensitivity
• Stability
• Adequateness
• Simplicity& economy
• Protective zone
• Concept of backup relaying
• Types of relaying
• PROTECTIVE AGAINST OVERVOLTAGE
• Lighting
• Types of lighting stroke
• Protective of electrical apparatus against travelling waves
• Operation of surge diverter\lighting arrester
• Classification of surge arrestor
• Coefficient of earthing
• Surge absorber
• Solid grounding
• Resistance earthing
• Advantage
• Disadvantage
• Reactance earthing
• Advantage
• Disadvantage
• Resonant grounding
• Earthing transformer
• Symmetrical fault analysis
• Methods
• Insulation co-ordination
• Unsymmetrical fault analysis
• Single line to ground fault
• Fault current
• Fault impedance
• Line to line fault

UNIT-2

• Operating principles and relay characteristics
• Relay
• Trip circuit operation
• Tripping schemes
• Relay with make type contact
• Relay with break type contact
• Electro magnet attraction relay
• Solenoid and plunger relay
• Balanced beam type relay
• Electromagnetic moving coil relay
• Calculation of relay operating time
• Directional power relay
• Directional induction type
• Differential relays
• Frequency relay
• Impedance relay
• Torque equation
• Advantages
• Disadvantages
• Directional impedance relay
• Reactance Relay
• Mho\admittance relay
• Static relay

UNIT-3
TRANSFORMER PROTECTION

• Common transformer fault
• Protective schemes for transformer protection
• 1 .Buchholz device
• 2 .Earth fault relay
• 3 .Over current relay
• 4 .Differential relay
• 5 .Harmonic restraint and harmonic blocking
• Drawbacks of differential protection 
• Protection of generators
• Classification
• Star connected alternator protection
• Delta connected alternated protection
• Stator interturn fault protection
• Restricted earth fault protection
• Unrestricted earth fault protection
• Unbalanced protection of generators
• Overload protection of stators
• Negative sequence protection relay
• Protection against abnormal running condition
• Motor protection requirements
• Comprehensive motor protection relay
• Protection circuit for induction motor
• Bus bar protection
• Advantage
• Disadvantage
• Instrument transformer
• Types
• Current transformer
• Application
• Design features
• Potential transformer
• Types
• Application
• Problems

UNIT-4
THEORY OF CIRCUIT INTERRRUPTION

• Field emission
• Thermionic emission
• Maintanence of arc
• Electric arc
• Arc extinction
• Low resistance or zero point extinction
• DC circuit breaking
• AC circuit breaking
• Derivation of rate of rise of TRV
• Factors
• Current chopping
• Problems

UNIT-5
CIRCUIT BREAKERS

• Classification
• Advantages 
• Disadvantages
• Features
• Limitation
• Application
• Circuit breaker ratings
• Testing of circuit breaking
• Comparison of circuit breakers
• Problems