18EE72 Power System Protection syllabus for EE

Introduction to Power System Protection:

Need for protective schemes, Nature and Cause of Faults, Types of Fault, Effects of Faults, Fault Statistics, Zones of Protection, Primary and Backup Protection, Essential Qualities of Protection, Performance of Protective Relaying, Classification of Protective Relays, Automatic Reclosing, Current Transformers for protection, Voltage Transformers for Protection.

Relay Construction and Operating Principles:

Introduction, Electromechanical Relays, Static Relays – Merits and Demerits of Static Relays, Numerical Relays, Comparison between Electromechanical Relays and Numerical Relays.

Overcurrent Protection:

Introduction, Time – current Characteristics, Current Setting, Time Setting.

Overcurrent Protection (continued):

Overcurrent Protective Schemes, Reverse Power or Directional Relay, Protection of Parallel Feeders, Protection of Ring Mains, Earth Fault and Phase Fault Protection, Combined Earth Fault and Phase Fault Protective Scheme, Phase Fault Protective Scheme, Directional Earth Fault Relay, Static Overcurrent Relays, Numerical Overcurrent Relays.

Distance Protection:

Introduction, Impedance Relay, Reactance Relay, Mho Relay, Angle Impedance Relay, Effect of Arc Resistance on the Performance of Distance Relays, Reach of Distance Relays. Effect of Power Surges(Power Swings) on Performance of Distance Relays, Effect of Line Length and Source Impedance on Performance of Distance Relays

Pilot Relaying Schemes:

Introduction, Wire Pilot Protection, Carrier Current Protection

Differential Protection:

Introduction, Differential Relays, Simple Differential Protection, Percentage or Biased Differential Relay, Differential Protection of 3 Phase Circuits, Balanced (Opposed) Voltage Differential Protection.

Rotating Machines Protection:

Introduction, Protection of Generators.

Transformer and Buszone Protection:

Introduction, Transformer Protection, Buszone Protection, Frame Leakage Protection.

Circuit Breakers:

Introduction, Fault Clearing Time of a Circuit Breaker, Arc Voltage, Arc Interruption, Restriking Voltage and Recovery Voltage, Current Chopping, Interruption of Capacitive Current, Classification of Circuit Breakers, Air – Break Circuit Breakers, Oil Circuit Breakers, Air – Blast Circuit Breakers, SF6 Circuit Breakers, Vacuum Circuit Breakers, High Voltage Direct Current Circuit Breakers, Rating of Circuit Breakers, Testing of Circuit Breakers.

Fuses:

Introductions, Definitions, Fuse Characteristics, Types of Fuses, Applications of HRC Fuses, Selection of Fuses, Discrimination.

Protection against Overvoltages:

Causes of Overvoltages, Lightning phenomena, Wave Shape of Voltage due to Lightning, Over Voltage due to Lightning, Klydonograph and Magnetic Link, Protection of Transmission Lines against Direct Lightning Strokes, Protection of Stations and Sub – Stations from Direct Strokes, Protection against Travelling Waves, Insulation Coordination, Basic Impulse Insulation Level (BIL).

Modern Trends in Power System Protection:

Introduction, gas insulated substation/switchgear (GIS).

Course Outcomes:

At the end of the course the student will be able to:

• Discuss performance of protective relays, components of protection scheme and relay terminology over current protection.
• Explain the working of distance relays and the effects of arc resistance, power swings, line length and source impedance on performance of distance relays.
• Discuss pilot protection, construction, operating principles and performance ofdifferential relays and discuss protection of generators, motors, transformer and Bus Zone Protection.
• Explain the construction and operation of different types of circuit breakers.
• Outline features of fuse, causes of overvoltages and its protection, also modern trends in Power System Protection.

Question paper pattern:

• The question paper will have ten questions.
• Each full question is for 20 marks.
• There will be 2 full questions (with a maximum of three sub questions in one full question) from each module.
• Each full question with sub questions will cover the contents under a module.
• Students will have to answer 5 full questions, selecting one full question from each module.

Text Books

1 Power System Protection and Switchgear Badri Ram, D.N. Vishwakarma McGraw Hill 2 nd Edition

2 Power System Protection and Switchgear BhuvaneshOza et al McGraw Hill 1 st Edition, 2010

Reference Books

1 Protection and Switchgear Bhavesh et al Oxford 1 st Edition, 2011

2 Power System Switchgear and Protection N. Veerappan S.R. Krishnamurthy S. Chand 1 st Edition, 2009

3 Fundamentals of Power System Protection Y.G.Paithankar S.R. Bhide PHI 1 st Edition, 2009