Switchgear and Protection

Chapter – 1 Principles of Protection
· Line diagram of a power system and its elements
· Faults and abnormalities, their causes, types and effects
· Functions of basic elements of a protective system
· Backup protection and its types
· Neutral earthing
· Methods of neutralearthing and its advantages

Chapter – 2 Over Voltage Protection
· Causes and effects of over voltages
· Methods of reducing over voltages
· Types ,Operating principles, applications of lightning arrestor
· Surge absorber

Chapter – 3 Protective Relays
· Concept of protective relaying
· Classification of relays and their selection
· Construction and working principle of relays electromagnetic, induction, reverse power, differential, distance, IDMT, & thermal relay
· Basic terms related to relays pick-up value, reset value and operating current.
· Settings of various types of relays
· Causes of failure of primary relaying
· Use & types of backup relays in power system

Chapter – 4 Instrument Transformers
· Instrument transformers used for protection
· Polarity marking of CT & PT and their specifications
· Connection diagram of CT & PT in a 1-phase and 3-phase protective systems

Chapter – 5 Circuit Interrupting Devices
· Necessity and types of interruption devices like ACB, OCB, AB Switch, SF6 and vacuum circuit breakers& their working principle
· Line diagram of a protective system showing different circuit interrupting devices
· Arc formation in CB& methods of arc extinction
· Terms related to circuit interruption wave form
· Requirement and types of isolators
· Difference between isolators & CB
· Types of fuses and their characteristic

Chapter – 6 Protection Schemes
· Abnormalities and faults in a power system and its effects
· Protection schemes for alternator
· Protection against prime mover failure and unbalance loading
· Protection of transformers
· Protection of transmission line and feeders
· Protection of induction motors