Protection & Switchgear Premium Lecture Notes prepared by Lavanya Edition. Specially for B.E Electrical and Electronics Engineering. Syllabus is based on Anna University , B.E Electrical and Electronics Engineering
Attachment: click hereCONTENT:
UNIT-1 INTRODUCTION (Pages: 34)
UNIT-2 OPERATING PRINCIPLES AND RELAY CHARACTERISTICS (Pages: 24)
UNIT-3 APPARATUS PROTECTION (Pages: 25)
UNIT-4 THEORY OF CIRCUIT INTERRUPTION (Pages: 11)
UNIT-5 CIRCUIT BREAKER (Pages: 11)
UNIT-1
INTRODUCTION
Relay
Protection
1. Primary protection
2. Backup protection
Types of backup protection
1. Relay backup protection
2. Breaker backup protection
3. Remote backup protection
4. Centrally coordinate protection
Qualities of protection relaying
Sensitivity factor
Protective zone
Types of relay
1. Electromagnetic attraction type relay
2. Induction type relay
3. Directional type relay
4. Relay based on timing
5. Distance type
6. Differential type
Fault analysis
Types of fault
1. Symmentrical faults
2. Unsymmentrical faults
Protection against over voltages
Waveform of lightning current
Types of lightning stroke
1. Direct stroke
2. Indirect stroke
Operation of surge diverter
Classification of surge diverter
1. Station type
2. Line type
3. Distribution and secondary type
Coefficient of earthing
Problems
Double line – ground fault
UNIT-2
OPERATING PRINCIPLES AND RELAY CHARACTERISTICS
Electromagnetic attraction relay
Over current relay
Non directional induction type over current relay
Relay of relay operating type
Differential relay
Types
1. Current differential relay
2. Biased beam relay
3. Voltage balance differential relay
Frequency relay
Distance relay
Torque equation
Directional impedance relay
Reactance relay
Mho/admittance relay
Static relay
Classification of measuring elements
Negative sequences relay
UNIT-3
APPARATUS PROTECTION
Transformer protection
Common transformer faults
Bucholtz relay
Advantages
Earth faults
Combined leakages and overload protection
Frame leakage protection
Protection of generators
Classification of generator faults
Stator faults protection
Restricted earth faults
Unbalanced protection of generator
Transmission generator or feeder protection
1. Parallel feeder protection
2. Tee feeder protection
3. Ring main protection
4. Translay protection
UNIT-4
THEORY OF CIRCUIT INTERRUPTION
Initiation of arc
Arc extinction
Effects of power factors
DC circuit breaker
UNIT-5
CIRCUIT BREAKER
Classification
1. According to interruption medium
a. Air blast CB
b. Vaccum CB
c. Oil CB
d. SF6 CB
2. According to operation
a. Gravity open CB
b. Gravity closed CB
c. Horizontal break CB
Advantages
Disadvantages
Rating of CB
Testing of CB
Comparision of CB
Advantages
Disadvantages
Problems
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