Turbo Generator IN INDIA

MANUFACTURING AND MANUFACTURING AND DESIGN OF DESIGN OF

INSULATION SYSTEM FOR INSULATION SYSTEM FOR AIR COOLED TURBO AIR COOLED TURBO

GENERATOR GENERATOR BY : P.VINAY KUMARBY : P.VINAY KUMAR

prefacepreface• Power is the basic necessity for Power is the basic necessity for

economic development of a country. economic development of a country.

• production of electrical energy its production of electrical energy its per capital consumption deemed as per capital consumption deemed as an index of standard of living. an index of standard of living.

• An AC generator works on the An AC generator works on the principle of ‘principle of ‘Electro Magnetic Electro Magnetic InductionInduction’. ’.

• Turbo generators are machines Turbo generators are machines which can generate high voltages which can generate high voltages and capable of delivering KA of and capable of delivering KA of currents currents

• the designer should be cautious in the designer should be cautious in designing the winding insulation. designing the winding insulation.

• insulation design plays a major role insulation design plays a major role on the life of the Turbo Generator on the life of the Turbo Generator

IntroductionIntroduction

• First half we discuss about First half we discuss about manufacture of a statormanufacture of a stator

• The latter half we stress more on The latter half we stress more on insulation design by V.P.I processinsulation design by V.P.I process

• Defination of insulation Defination of insulation

manufacture of manufacture of generatorgenerator

• generator manufacturing can be generator manufacturing can be broadly divided into three main broadly divided into three main parts:parts:

• 1. Stator manufacture 1. Stator manufacture

• 2. Rotor manufacture2. Rotor manufacture

• 3. Exciter manufacture3. Exciter manufacture

fLowchart of various stages I a generator manufacture

STATOR MANUFACTURE STATOR MANUFACTURE PROCESS:PROCESS:

Stator core construction and Stator core construction and Coil construction and their assembly. Coil construction and their assembly.

single form wound coil being inserted into two slots

Stator core constructionStator core construction

• 1.PREPARATION OF STATOR 1.PREPARATION OF STATOR LAMINATIONSLAMINATIONS

• a RECEPTION OF SILICON STEEL ROLLS a RECEPTION OF SILICON STEEL ROLLS b SHEARING b SHEARING

• c BLANKING AND NOTCHINGc BLANKING AND NOTCHING::

• i) Compound notching i) Compound notching

• ii) Individual notching ii) Individual notching

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• D. D. DEBURRING OPERATIONDEBURRING OPERATION

• E. E. VARNISHING:VARNISHING: sheets are dried at a sheets are dried at a temperature of around 260 – 350 oCtemperature of around 260 – 350 oC

STATOR CORE ASSEMBLYSTATOR CORE ASSEMBLY

• A. A. TRAIL PACKET ASSEMBLYTRAIL PACKET ASSEMBLY

• B. B. NORMAL CORE ASSEMBLYNORMAL CORE ASSEMBLY

• 1) Stepped packed assembly1) Stepped packed assembly

• 2) normal packet assembly 2) normal packet assembly

• a) In process pressings:a) In process pressings:

• b) Fitting of clamping bolts: b) Fitting of clamping bolts:

STATOR WINDING INSULATION STATOR WINDING INSULATION SYSTEM FEATURES SYSTEM FEATURES

• Strand InsulationStrand Insulation

• Turn InsulationTurn Insulation

• Ground wall Insulation Ground wall Insulation

• CLASSIFICATION OF CLASSIFICATION OF INSULATING MATERIAL:INSULATING MATERIAL:

Picture of above shit Picture of above shit

Stator WindingStator Winding

• The most prime part of a winding is The most prime part of a winding is insulationinsulation

Photographs of end windings and slots of random wound stator (Courtesy TECO Westing housePhotographs of end windings and slots of random wound stator (Courtesy TECO Westing house

MANUFACTURE OF STATOR MANUFACTURE OF STATOR COILS:COILS:

A) For resin poor processA) For resin poor process • Reception of copper Reception of copper

conductors:conductors: • TranspositionTransposition • Putty operation:Putty operation:• Stack consolidation:Stack consolidation: • Bending:Bending: • Final taping:Final taping:

• FOR RESIN RICH PROCESSFOR RESIN RICH PROCESS

• The coil manufacture is same as in The coil manufacture is same as in case of resin poor but differ in a few case of resin poor but differ in a few stages stages

• Putty work:Putty work:

• Final tapingFinal taping

• Final baking:Final baking:

• 10.1 ADVANTAGES OF RESIN POOR SYSTEM OF 10.1 ADVANTAGES OF RESIN POOR SYSTEM OF INSULATION:INSULATION:

• It has better dielectric strengthIt has better dielectric strength• Heat transfer coefficient is much betterHeat transfer coefficient is much better• It gives better capacitance resulting in less dielectric losses It gives better capacitance resulting in less dielectric losses

due to which the insulation life will be moredue to which the insulation life will be more• The cost will be less and it is latest technologyThe cost will be less and it is latest technology• Reduction in time cycle and consumption for MW also less Reduction in time cycle and consumption for MW also less

and it gives high qualityand it gives high quality

• DISADVANTAGES OF RESIN POOR SYSTEM OF DISADVANTAGES OF RESIN POOR SYSTEM OF INSULATION:INSULATION:

• If any short circuit is noticed, the repairing process is If any short circuit is noticed, the repairing process is difficult and need of excess resin from outside.difficult and need of excess resin from outside.

• Dependability for basic insulating material on foreign Dependability for basic insulating material on foreign supplysupply

• Assembly of stator:Assembly of stator:

• Reception of stator core:Reception of stator core:

• Winding holder’s assembly Winding holder’s assembly – STIFFNER ASSEMBLYSTIFFNER ASSEMBLY

• Eye formation Eye formation

• Connecting rings assembly:Connecting rings assembly:

• Phase connectors: Phase connectors:

– ADVANTAGES OF RESIN RICH SYSTEM OF INSULATION:ADVANTAGES OF RESIN RICH SYSTEM OF INSULATION:• Better quality and reliability is obtained Better quality and reliability is obtained • In case of any fault (phase - ground/ phase – phase short) In case of any fault (phase - ground/ phase – phase short)

carrying the repair process is very easy.carrying the repair process is very easy.• Addition of excess resin will be avoided because of using Addition of excess resin will be avoided because of using

resin rich mica taperesin rich mica tape

– DISADVANTAGES OF RESIN RICH SYSTEM OF DISADVANTAGES OF RESIN RICH SYSTEM OF INSULATION:INSULATION:

• It is a very long procedureIt is a very long procedure• Due to fully manual oriented process, the cost is moreDue to fully manual oriented process, the cost is more• It is possible to process stator bars only.It is possible to process stator bars only.• Even though the advantages and disadvantages of both Even though the advantages and disadvantages of both

the process are explained above, resin poor process is the process are explained above, resin poor process is the best of all, as the resin content used is almost only the best of all, as the resin content used is almost only 35% compared to resin poor process and also show good 35% compared to resin poor process and also show good insulation properties justified in the later sections.insulation properties justified in the later sections.

THE VPI PROCESSTHE VPI PROCESS

• INTRODUCTION TO VACUUM INTRODUCTION TO VACUUM PRESSURE IMPREGNATION PRESSURE IMPREGNATION SYSTEM (VPISYSTEM (VPI ) )

• Drawback of earlier VPI SYSTEM Drawback of earlier VPI SYSTEM

Vacuum Pressure Impregnation Vacuum Pressure Impregnation of resin poor insulated jobs of resin poor insulated jobs

• 1. Preheating1. Preheating• 2. Lifting and shifting2. Lifting and shifting• 3. Vacuum cycle3. Vacuum cycle• 4. Vacuum drop test4. Vacuum drop test• 5. Heating the resin5. Heating the resin• 6. Resin admission.6. Resin admission.• 7. Resin settling7. Resin settling• 8. Pressure cycle8. Pressure cycle

• 9. Aeration 9. Aeration

• 10. Post curing cycle10. Post curing cycle

• 11. Cleaning11. Cleaning