Protection and Switchgear

EE3601

PROTECTION AND SWITCHGEAR

COURSE OBJECTIVES:

• To understand the significance of protection, protection schemes and role of earthing.

• To study the characteristics, functions and application areas of various relays.

• To acquire practical knowledge about common faults in power system apparatus and applying suitable protective schemes.

• To understand the functioning of static relays and Numerical protection concepts.

• To understand the problems associated with circuit breaking and to discuss about various circuit breakers.

UNIT I

PROTECTION SCHEMES

Significance and need for protective schemes - nature and causes of faults types of faults Effects of faults - Zones of protection and essential qualities of protection - Types of Protection schemes - Power system Grounding and Methods of Grounding.

UNIT II

BASICS OF RELAYS

Operating principles of relays -Universal torque equation - R-X diagram -Electromagnetic Relays - Over current, Directional and non-directional, Distance, Differential, Negative sequence and Under frequency relays.

UNIT III

OVERVIEW OF EQUIPMENT PROTECTION

Current transformers and Potential transformers and their applications in protection schemes - Protection of transformer, generator, motor, bus bars and transmission line.

UNIT IV

STATIC RELAYS AND NUMERICAL PROTECTION

Static relays Phase, Amplitude Comparators - Synthesis of various relays using Static comparators Block diagram of Numerical relays - Over current protection, transformer differential protection, and distantce protection of transmission lines.

UNIT V

CIRCUIT BREAKERS

Physics of arcing phenomenon and arc interruption - DC and AC circuit breaking - re-striking voltage and recovery voltage - rate of rise of recovery voltage - current chopping - interruption of capacitive current - resistance switching Types of circuit breakers - air blast, oil, SF6 and vacuum circuit breakers - comparison of different circuit breakers - HVDC Breaker.

TOTAL: 45 PERIODS

COURSE OUTCOMES:

Upon the successful completion of the course, students will have the ability to:

CO1: Understand and select proper protective scheme and type of earthing.

CO2: Explain the operating principles of various relays.

CO3: Suggest suitable protective scheme for the protection of various power system apparatus.

CO4: Analyze the importance of static relays and numerical relays in power system protection.

CO5: Summarize the merits and demerits and application areas of various circuit breakers.

TEXT BOOKS:

1. Sunil S.Rao, 'Switchgear and Protection', Khanna Publishers, New Delhi, Four Edition, 2010.

2. Badri Ram B.H. Vishwakarma, 'Power System Protection and Switchgear', New Age International Pvt Ltd Publishers, Second Edition 2011.

3. B.Rabindranath and N.Chander, 'Power System Protection and Switchgear', New Age International (P) Ltd., Second Edition, 2018.

4. Arun Ingole, 'Switch Gear and Protection' Pearson Education, 2018.

REFERENCES

1. Y.G.Paithankar and S.R.Bhide, 'Fundamentals of power system protection', Second Edition, Prentice Hall of India Pvt. Ltd., New Delhi, 2013.

2. C.L.Wadhwa, 'Electrical Power Systems', 6th Edition, New Age International (P) Ltd., 2018 3. VK Metha," Principles of Power Systems", S. Chand, Reprint, 2013

4. Bhavesh Bhalja, R.P. Maheshwari, Nilesh G. Chotani,'Protection and Switchgear' Oxford University Press, 2nd Edition 2018.