Main Generation Flashcards
How does Main Generator system produce power & where does it go when it does produce ?
.Mechanical power to electrical power
.provide power to switchyard
.provide power to non-class systems
.provide power to excitation system(DC voltage induced to rotor)
What is the sequence of components in Main Generating system include ?
.Main Generator
.Isolated phase busses
.Main transformer bank (24kv->525kv)
.Tie Lines to switchyard
.Unit Aux. Transformer(24kv->13.8kv)
Major components of Main Generator ?
.Generator casing
.Stator
.Rotor
.Collector
What is included in the Generating casing?
.Stator Frame
.End Shields
.Excitation Dome
.Lower Frame Extension
What is inside the Stator frame & what does it do for cooling ?
.Stator Windings
.Stator Core
.Rotor
.Provides multiple paths for cooling Hydrogen Gas
What do End Shields do?
Used to support weight of rotor and contain Hydrogen gas inside the casing by using shaft seals
Where is the Excitation Dome ? And what does it contain?
Mounted on stator frame, containing Hydrogen Tubes and Coolers
How does power exit the generator casing?
Through the high voltage bushings mounted in the lower frame extension.
What cools High Voltage bushings in Lower Frame Extension ?
Stator Cooling Water (CE)
What is purpose of Stator ?
Generate voltage and current supply to main transformer & Unit Aux. Transformer (via isophase bus)
What is the Stator Core?
Contains insulated slots for armature bars to go through
What is the stator made of?
3 separate insulated copper bars wrapped in a ring through a laminated core.
What cools the stator windings?
Stator Cooling Water (CE)
What is the purpose of rotor ??
Produces magnetic flux to cut armature windings, creating voltage & current
How does the rotor operate ?
Windings are held together by retaining rings & DC voltage is induced to create magnetic field
What cools Field Windings on Rotor ?
Hydrogen gas flowing over bars through casing by fans installed on each end of generator
What is purpose of the Collector?
Applies DC voltage to rotor inducing rotating magnetic field
How is DC power induced into rotor ?
By slip rings & carbon brushes, through collectors carbon brushes to rotor slip rings
How is the Collector cooled ?
By mounted fan circulating air in Collector housing & through cooler with Normal chilled water
What’re isophase buses used for ?
Conducts power from Main Generator to Main Transformer & Aux. Transformer
How do isophase busses operate ?
The 3 phases from generator are isolated from each other. Insulated conductor in water/dust tight enclosure
What cools the Isophase busses ?
Forced air from Isophase Bus Duct Cooling System (CE)
How many bushings are there & what’re they called on Main Transformer?
High voltage bushing->switch yard (525kv)
Low Voltage Bushing->primary windings (24kv)
Neutral Bushing ->grounded
What’re the primary and secondary windings for in main transformer?
.Primary is 24kv from generator
.Secondary is 525kv out transformer to the switchyard