Power Plant Electrical Network Design, Analysis, Protection
and Control
The electrical network of a typical thermal power plant
consists of the following components
-
Main
electrical generator
-
Isolated
phase bus duct
-
Step up transformer
-
Station auxiliary transformer
-
Non segregated phase bus duct
-
Station startup transformer
-
Switch gears
-
Secondary unit substations
-
Motor control centers
Typically power plants will function 24 hours a day and 365
days a year to provide continuous power to meet the electricity demand [as this
power cannot be stored and retrieved]. For proper functioning of the power
plant, the plant auxiliary system needs to function reliably without any loss
of power and a reliable electrical distribution network is a must. The design
of the power plant auxiliary system is usually typically same as this art has
been perfected over a long period.
The power generated by the electrical generator is typically
stepped up to the higher kV level for power evacuation to the external
transmission system. The interconnection between the generator and the stepup
transformer is by an isolated bus duct. A unit auxiliary transformer [UAT] is
connected to the generator terminal to feed plant auxiliary loads. There is
another station start up transformer which is normally not connected to the
plant auxiliary loads under running conditions but is used for purpose of the
start up of the plant, when the generator is not yet started. This start up
transformer is connected between the external transmission grid and the plant
auxiliaries.
Apart from detailed engineering services, the major power
system studies for the power plant distribution network are,
Frequency Control Engineering for Power Plants
Power Plant Auxiliary Substation Design