8EE3 STATIC PROTECTIVE RELAYS
 

1. INTRODUCTION: Basic for static relay development, classification of static relays, microprocessor based relays, Digital protection, advantages of digital protection. Basic protection scheme using microcomputer.

2. STATIC RELAY COMPONENTS: Semi conductor devices, static switching, logic circuits and relay logic. Integrated circuits, transducers and interface devices, replica impedances, time delay devices, sequence filters, voltage regulators.

3. STATIC COMPARATORS: Single input multi-input comparators. Amplitude comparator-integrating, instantaneous and sampling techniques; phase comparators-vector product & coincidence techniques. Direct phase comparison, phase splitting technique, integrating phase comparison. Duality of amplitude and phase comparison.

4. STATIC RELAYS: Over current elays, directional over current relays using Hall crystal, rectifier bridge, instantaneous since comparator. Distance relay, impendence Reactance admittance, offset mho, trapezoidal and elliptical characteristics. Differential relays.

5. SCHEMES OF PROTECTION: Static switching scheme of distance relays. Polyphone distance relays. Static differential protection for generators, transformer and Bus zone. static protection for motors, single-phase prevented.

6. MODERN TRENDS IN POWER SYSTEM PROTECTION: Auto recoiling, frequency relay-under frequency ,over frequency and rate of change of frequency relay, static ultra high speed directional comparison line protection, reliability-dependability, security, redundancy, factors affecting the performance of relays, design reliability of complete protection schemes; improving technical reliability; routine tests, type tests and reliability tests of relays.

RECOMMENDED BOOKS:

1. TMS Rao-Static Relays

2. M. Chander-Switchgear protection

3. S.S. Rao-Switchgear and protection