PROGRAMME: B.E. Electrical Engineering-VIII Semester
Course: EE802 Power System Protection
Faults in power systems, single line diagram, equivalent impedance diagram, per unit reactances. Analysis (using matrices) of power systems by symmetrical components under:
(a) Three phase short circuit.
(b) Line to line fault.
(c) Line to ground fault.
(d) Double line to ground fault.
Sequence networks and their inter connections for different types of faults, effects of fault impedance. Current Limiting Reactors: Applications, types, construction and location of current limiting reactors, short circuit calculation using reactors.
General considerations, sensing of faults, construction of electro-magnetic attraction and induction types relays, Buchholz and negative sequence relay, concept of reset, pick up, inverse time and definite time characteristics, over current , over voltage, directional, differential and distance relays on R-X diagram. Static Relays: Introduction, advantage and limitation of static relays, static over current, directional, distance and differential relays.
Types & detection of faults and their effects, alternator protection scheme (stator, rotor, reverse power protection etc.). Power transformer protection (external and internal faults protection), generator-transformer unit protection scheme, bus bar protection. Transmission line protection (current/time grading, distance), Pilot relaying schemes, power line carrier protection.
Theory of current interruption- energy balance and recovery rate theory, arc quenching, recovery and restriking voltages. Types of circuit breakers. bulk oil and minimum oil, air break and air blast, sulphur hexa fluride (SF6) and vacuum circuit breakers. Rating selection and testing of circuit breakers/operating mechanisms. LT switchgear, HRC fuses, types construction and applications.
Electronic relays, static relays functional circuits: comparators, level detectors, logic and training circuits, microprocessor and computer based protection schemes, software development for protection, security & reliability.
EE802 Power System Protection List of Experiments: Operating Characteristics of
1) Over Voltage Relays
2) IDMT Relays
3) Percentage based differential relays
4) Determination of instantaneous relays
5) Buchholz relays
6) Solid state over current relays
EE802 Power System Protection References:
- Van A. R & Warrington C., “ Protective Relays : Their Theory and Practice”, Vol 1 & 2, Chapman and Hall.
- Paithankar Y. O.,” Transmission Network Protection: Theory and Practice”, Marcel Deicker, Inc.
- GEC Measurements,” Protective Relays : Application Guide”, GEC Measurements.
- Masson R.J., Art & Science of Protective Relaying.
- J & P Switchgear handbook Ravindra Nath B., and Chandar M., Power systems protection and switchgear
- Rao Sunil S, Switchgear and protection.
- Crane P.H.C., Switchgear Principle.
- The Elementary Council, “Power System Protection”, Vol.1,2 &3, Peter Peregrinus Ltd.
- Badriram & Vishwakarma, Power System Protection. Ravindranath & Chander, Power System Protection & Switchgear.