TURBO GENERATORS

Submitted to:Mr. Uttam Kumar Gupta (Asst. Prof)Mr. Rahul Agarwal (Asst. Prof)

Submitted by:Akanksha Gupta 13EE004 (EE)

OVERVIEW OF BHEL

• BHEL is the largest engineering and manufacturing enterprise in India.

• The first electrical manufacturing unit of the country was setup at Bhopal.

• BHEL, Haridwar complex consist of two manufacturing units HEEP and CFFP.

HEEP CLASSIFICATION

Block-1 (Electrical Machines)

Block-2 (Fabricatio

n Block)

Block-3 (Turbine and

Auxiliary block)

Block-4 (Feeder Block)

Block -5(Heat exchange

and Forging block)

Block-6 (Machining)

Block – 7 (Stamping and

dia manufacturing)

Products

Turbo Generators Brushless Exciters

TURBO GENERATORS

• Turbo generators were first invented by

a Hungarian engineer OTTO BLATHY and its principle was then

given by Faraday’s.

• It consists of two separate units:

(i) Turbine

(ii) Generator

A turbo generator is a large electricity generator driven by

a prime mover (steam/gas turbine) and is directly

connected to electric generator for the generation of

electricity. They are mostly used as large capacity

generator.

Turbo Generators

Stator Rotor

•Stator Frame

•Stator Core

•Stator Winding

•End Cover

•Bushings

•Rotor Shaft

•Rotor Windings

•Rotor Retaining Ring

•Field Connection

STATOR FRAME

• A stator frame consists of a cylindrical center section and two end shields which are gas tight and pressure resistant.

• It accommodates the active part of the stator i.e., the stator core and the stator windings.

• It provides provision for H2/CO2 filling and temperature measurements.

STATOR CORE• The stator core is made from the insulated

electrical sheet lamination to minimize the eddy current losses.

• The purpose of stator core is to:

(i) Provide link between the core and the rotor.

(ii) Support the stator winding.

(iii)To carry the magnetic flux generated by rotor winding.

STATOR WINDING• The stator has a 3-phase, double layer,

short pitched and bar type of windings having two parallel paths. Each slot accommodates two bars.

• The bars consist of separately insulated strands which are transposed to reduce skin effect losses.

• The slot’s lower bars and slot’s upper bars are displaced from each other by one winding pitch and connected together by bus bars.

END COVER The ends of the stator frame are

closed by pressure containing end

shields. The end covers are made up

of non- magnetic material to reduce

stray load and eddy current losses.

BUSHINGS The beginning and ends of

the three phase windings are brought out from the stator frame through bushings, which provides high voltage insulation.

ROTOR• The rotating part of turbo generator is

rotor.

• The rotor houses the field winding.

• When the rotor rotates , the lines of

magnetic flux cut through the winding.

• Rotor of cylindrical type is used in

turbo generator.

ROTOR SHAFT Rotor shaft is a single piece forming

manufactured castings. It is forged

from a vacuum cast steel slots for

insulation of the field winding are

made into the rotor body.

EXCITATION SYSTEM

Brushless Excitation

Pilot Exciter Main Exciter Rectifier Wheel

PILOT EXCITER

Three phase pilot exciter is 16 pole revolving field units. The stator

accommodates three phase armature winding and magnetic poles are placed

on the rotor. Thus rotating flux is produced which cuts the stationary

armature conductors and three phase AC is generated.

MAIN EXCITER

The three phase main exciter is a 6 pole armature type unit. The stator frame

accommodates the field winding. The field winding is placed on the magnetic

poles. The armature consists of stacked lamination and the three phase

winding is inserted into the slots of the laminated armature.

RECTIFIER WHEEL

The main component in the rectifier wheel is silicon diodes which are

arranged in rectifier wheel in three phase bridge circuit.

The direct current from rectifier wheel is fed to DC leads and then to the field

winding of the rotor.

ADVANTAGES OF BRUSHLESS EXCITER

• Eliminates slip rings and brushes.

• Eliminates all problems associated with transfer of current via sliding contacts.

• Eliminates the hazard of changing brushes on load.

• Brush losses are eliminated.

• Minimum operating and maintenance cost.

• High response excitation with fast acting AVR.

THANK YOU