EE8602 – NOTES & QP
EE8602 – SYLLABUS
UNIT I PROTECTION SCHEMES
Principles and need for protective schemes — nature and causes of faults — types of faults — Methods of Grounding — Zones of protection and essential qualities of protection — Protection scheme
UNIT II ELECTROMAGNETIC RELAYS
Operating principles of relays — the Universal relay — Torque equation — R-X diagram — Electromagnetic Relays — Over current, Directional, Distance, Differential, Negative sequence and Under frequency relays.
UNIT III APPARATUS 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, distant 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 — resistance switching — current chopping — interruption of capacitive current — Types of circuit breakers — air blast, air break, oil, SF6, MCBs, MCCBs and vacuum circuit breakers — comparison of different circuit breakers — Rating and selection of Circuit breakers.