Switch Gear & Fault Analysis — Summer 2018

Define ‘fault’ in power system. Discuss the types of faults and causes of fault. How the faults can be minimized?

Discuss the necessity of protection system and explain fault clearing process.

Explain the following term: (1) Isolator (2) Lightning Arrester (3) Recovery voltage

Explain the principle of circulating current differential protection. Discuss the difficulties with it.

Write a brief note on IDMT relay.

Discuss Air blast circuit breaker with neat diagram.

Explain construction and working of electromagnetic induction disc type relay. Also discuss Plug setting and Time setting in induction disc relay.

Explain the effect and derive the expression of current due to sudden short circuit of R-Lseries circuit.

Explain the construction of vacuum circuit breaker with neat diagram.

Discuss the construction and working of HRC fuse with its advantages and disadvantages.

Explain the double line to ground fault on an unloaded generator.

Explain the attracted armature relay with necessary diagram.

Discuss SF6 - circuit breaker with necessary diagram.

Explain Auto-reclosure.

Explain the principle of distance protection by R-Xdiagram and explain the operating characteristics of an impedance relay.

Explain Resistance Switching and Current Chopping with neat sketch.

Write a short note on micro-controller based digital relay.