Synchronous generator and Static Excitation system
Excitation System of Generator
description of excitation transformer
Technical
Basic construction details of 600MW unit
brushless excitation system
hi
Excitation system is one of the most important parts of the synchronous generators. Excitation system of the generator comprises from machines, devices and appliances that are intended to provide direct current to the generator field winding and this
Information and intelligence are two vital columns on which development of humankind rise and knowledge has significant impact on operating of society. Student assessment is a crucial part of teaching and is done through the process of examinations a
Generator Seal Oil SystemFull description
Full description
Generator excitation system
Excitation:The process of generating a magnetic field by means of an electric current is called excitation.
Purpose of generator excitation system: 1.The main purpose of excitation system for generator is to supply the power source to the rotor field coil. 2.The excitation system is used to control the excitation of the rotating field in the armature.
*otating type -ithin the family of rotating exciters there are numerous types that can be found operating on all types and si/es of generators. The basic 0inds of rotating exciters are motor or shaft drien and separately selfexcited or busfed systems.
The shaftdrien rotating excitation system has been the most widely used excita tion source in the past. &t is used for small and large turbine generators. The basic con figuration is a stationary armature and a rotating field. The ac output of the alternator is rectified by stationary diodes physically located off o ff the generator and fed to the main rotor slip rings as dc current. *egulation of the current output is achieed by phase control of thyristors in the alternator field power circuit. "igure +.13 shows the typical basic circuit for a shaftdrien excitation system.
tatic type 'n external source of power 4often the generator isolated phase bus5 is used to supply ac power to an excitation transformer.. The transformer output is fed to transformer a threephase controlled rectifier bridge for conersion to dc. The re 6uired generator field oltage is obtained by properly controlling the thyristor firing as in the rotating exciter. exciter. The standard control generally consists of an ac 4auto5 control mode for regulating generator terminal oltage and a dc 4manual5 control mode for regulating exciter field oltage 4see "ig. +.175.
1. )ain e6uipments: a. *ectifier transformer. b. Thyristor rectifier ban0s. c. Excitation startup and field discharge e6uipment. e6u ipment. d. *egulation and operation control circuit. 2.'dantages: a. "ast *esponse b. )ore efficient and low maintenance
*ectify:to conert ac to dc. fire : ' transition from nonconduction no nconduction to conduc tion in an ioni/ing switching deice. "iring:The act or process of adding fuel and air to a furnace.
'8* '8* means m eans 'utomatic 8oltage *egula *egulator tor.. &t is usually used in the excitation of a generator. generator. '8* regulate the excitation oltage of the generator according to the demand. This deice is mainly used for 0eeping the terminal olage of generator at constant leel irrespectie of load.
,rushless excitation system The brushless excitation system is most widely used for gas turbine units with aircooled generators but also can be found in steam generators of eery rating. &t consists of a highfre6uency ac generator with a rotating fused diode diode as sembly a static oltage regulator for excitation sembly control and a transformer power supply supply.. The exciter is generally attached as an extension of the generator shaft.
)ain parts 1.Pilot exciter 2.main exciter +.*ectifier wheel 9.'8*
The three phase pilot exciter has a reoling field with permanent magnet poles.The armature armature winding is housed on the stator. stator. The three phase a.c. generated by the pilot exciter is rectified and controlled by automatic oltage regulator to proide ariable .%. for exciting the main exciter. exciter. The three phase main exciter has stationary field with reoling armature. Thus three phase a.c. power is produced in main exciter exc iter which is rectified by rotating rectifier bridge and is fed to the field winding of the rotor 4turbo generator5 through dc leads.
