22 November 2011

Thermal Power Plant Interview Questions-Answers(Set 3)

What are the major electric systems in Thermal Power Plant?

Answer: Major electrical equipment in thermal power plant are

  • Turbine Generator
  • Exciter System
  • Generator Protection System
  • Generator Transformer
  • HT/LT switch gear
  • Electrical Switch-yard

What are the different Generator Protections employed in Thermal Power Plants?

Answer: Faults in the windings, Over load protection, Over heating of windings or bearings, Over speed protection, Loss of Excitation protection, Motoring operation protection, Inadvertent energisation, single phase or unbalanced current protection, out of step operation protection, sub-synchronous oscillations protection and earth fault protection

How Generator Transformer is cooled in Thermal Power Plant?

Answer: MVA power rating of the Generator Transformer will be equal to the alternator. Hence lot of heat will be generated while generator transformer is under operation. Oil Forced Air Forced (OFAF) type of cooling is employed for generator transformer

What are different types of circuit breakers employed in thermal power plant?

Answer: For low voltage operation 415/220V vacuum circuit breakers or air break circuit breakers are employed. For voltage ratings about 6.6kV and beyond SF6 circuit breakers are employed.

What type of cooling is provided for Generator in power plant?

Answer: Hydrogen gas cooling is employed for large size generators because of better heat carrying ability of the hydrogen. Hydrogen cooling is provided for rotors and core of the generator. Water cooling is provided for the stator of the alternator.

1 comment:

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