PRESENTATION ON MANUFACTURING OF TRANSFORMER By Dhruv Jimit
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The document outlines the construction and design considerations for transformers, focusing on core materials like crgo, winding types, insulation methods, and cooling systems. It details components such as bushings, conservators, and relays that ensure operational efficiency and safety of transformers. Additionally, it discusses the manufacturing processes and testing protocols essential for transformer quality assurance.
PRESENTATION ON MANUFACTURING OF TRANSFORMER By Dhruv Jimit
- 1. Prepared by: Jimit Dhruv Elect.Engg,Dept. Valiya Institute Of Technology-Valiya
- 2. Introduction Core material: Basic material are Alloy Steel having main content Silicon & carbon Which increases permeability & reduces losses
- 3. HRS: HRS not used now a days As it has random direction &hard to measure Magnetic properties CRGOS: CRGOS shows excellent Magnetic properties So CRGOS is more used
- 4. Core construction Due to Pulsating flux, core should be laminated Transformer of larger size may forms in cut “C” or cut “E” type. Types of Interleaving: I. Simple Interleaving II. Meter core Interleaving: 1)45 ˙ 2) 33 ˙ /55 ˙ overlapping In 3-Ø Shell type transformer middle winding is reversed If not then 73% more core is used which leads in increase in over all cost
- 6. Concentric Sandwich Spiral: It is used 100 A& for low Voltage Winding Mechanically very strong Sandwich: mostly used Helical :Intermediate for shell type transformer range of current Control leakage Suitable for LV winding reactance of large transformer HV & LV are near so leakage flux is reduced Cross-over: suitable of mmf of each section is current not exceeding 20 same. A Use for HV winding of small transformer Continuous disc: no of turns wound radially over one another separated by spacers HV winding Mechanically strong
- 7. Insulations Two main kinds of Insulations: 1. Major Insulation: Insulating cylinder between LV & core Also between HV & LV Insulating barriers between limbs, coils & core yoke Oil impregnated paper used as it has high dielectric strength 2. Minor Insulation: Insulation between individual turns & between layers Conductor Insulation: paper&cotton Air insulated Transformer insulation used is glass tap
- 8. Bushing Up to 66kv non-condenser bushing are used is porcelain & oil filled Above 66kv condenser bushing are used for economic reasons. Condenser type bushing: It is formed by inserting Aluminum foiled layers into a paper winding at predetermined radius. “Partial capacitance” In outdoor substation the bushing are covered by a porcelain rain shade
- 9. Tapping Main two location: 1. Inside Tank 2. Outside Tank Considered as integral part of transformer Tapping operation (1)On load (2)Off load tap changer tap changer Tapping is terminated just bellow oil level External handle Taping is done on HV winding Provided in middle (axial & radial force)
- 10. Transformer Tank Plain sheet steel Tank Tube Tank Corrugated Tank Radiator Tank Tank with separate coolers
- 11. Conservator What is Conservator ? The expansion of oil from Transformer tank takes up in Conservator When oil contracts, air from atmosphere enters in Conservator . Risk of contamination of oil in transformer Breather valve is mounted to avoide moisture Breather contain silica in it
- 12. Buchholz Relay Operation: Gas operated relay AT the time of fault to maintain the continuity of the supply Fault detected particularly in incipient stage , major fault can be avoided Which is placed between conservator and transformer tank
- 13. Transformer oil Double purpose : ie cooling & Insulating Permittivity is 2.5 As per I.A.S breakdown strength of oil used must be 50kv RMS Major disadvantage is sluging To overcome this, synthetic oil is prefered One of the e.g is Chlorinated dephenyl is a synthetic oil its permittivity is 4.5
- 14. WORKSHOP(TPT DEPT.) WINDING SHOP CORE & ACTIVE PART FINAL ASSEMBLY QUALITY TEST FINAL TESTING
- 15. WINDING SHOP TYPES OF WINDING i. NORMAL WINDING ii. INTERLEAVE WINDING iii. TERITARY WINDING ROTARY HORIZONTAL HELICAL K- MACHINES TRANSPOSITION TYPE CONTINUOUS VERTICAL DISC • End Rings & shielding for prevention purpose
- 16. Conductor Insulation: 1. Precompressed press board insulation(CRIP PAPER) 2. Craft paper 3. Also spacers as insulation Moisture Control Winding Auto Clave: Uses temp. of 110º C to 130º C and Vacuum of about 0.4 to 0.5 mbar. Insulating Oven : Uses Heating Only Pressure Machine Brazing Machine with use of SILPHOS ALLOY Post Insulation
- 17. PROCEDURE:
- 18. CORE & ACTIVE PART ACTIVE PART C.R.G.O. STRIPS 1-STRIP HAS WIDTH OF 0.27 mm COIL OR WINDING ASSEMBLY PROCEDURE: Manufacturing of LIMB Core Insulation Removal of TOP FRAM for Coil assembly Winding insulation detail TOP YOKE FILLING VAPOUR PHASE OVEN HV & LV leads from top & bottom to the bushings REGULATING COILS to the tap changer
- 19. FINAL ASSEMBLY Installation of active part and assembly of accessories TRANSFORMER TANK • JOINED AT BELL TYPE BOTTOM SIDE • JOINED AT CONVECTIONAL TYPE UPPER SIDE
- 20. ACCESSORIES: Blanker : Leakage of oil & Radiators adjointment Buchholz Relay: To trip the transformer OSR (oil serge relay): To indicate the level and quality of oil MOLG(magnate oil gage): It indicates the level of oil in the conservator Breather Valve: Provide dry air using silica gel and have air seal of neoprene Cooling Equipment: Generally for cooling of oil in a tank 1. Radiators 2. Thermosyphan
- 21. Method of Cooling: i. ONAN ii. ONAF iii. OFAF iv. For very high temp using HEAT EXCHANGER CT(Current Transformer):Two purposes; 1. Winding temp indicator (WTI) 2. Oil temp indicator (OTI) BUSHINGS: The leads from top and bottom of the winding are brought out to a length of few cm only and the outdoor terminal of the transformer are provided by bushings
- 22. PROCEDURE Vacuuming of Tank(up to 0.3 mbar) for about 24hrs to 36hrs The Leak Rate Test with the use of water & air Oil Test which includes BDV & PPM Oil Filling After the IMPREGNATION TIME the whole accessories are to be attached.
- 23. QUALITY TEST ANALYSIS WITH “SIGMA CARD” Sigma card includes below required data Design Process Time M/C size specification Process of manufacturing Dimension specification Testing specification Information about control points
- 24. FINAL TESTING ROUTINE TESTS TYPE TESTS NO LOAD TETS TEMPRETURE TEST LOAD LOSS INSULATION IMPULSE TEST TEST CAPACITANCE & ZERO SEQUENCE TAN δ IMPEDANCE TEST SEPARATE SOURCE HARMONIC AND NOISE LEVEL TEST INDUCED OVER VOLTAGE WINDING TEST VOLTAGE RATIO
- 25. CT (CURRENT TRANSFORMER) Generally CT is use for the below four purposes: Measurement of Current Measurement of Power Isolation between High voltage and Low Voltage Inputs to Relays & Protection Systems PROCEDURE OF CURRENT TRANSFORMER: CO NDUCTORS USES :ALUMINIUM OR COPPER(HIGH CURRENT RATING) In the manufacturing of the primary winding or protection core there will be the creation of the capacitance as below. GRADING & SUB GRADING. MAIN GRADING HAS WRAPPED ALUMINIUM FOIL & CRIP PAPER AT 300MM DISTANCE PERFORATED ALU. FOIL (400MM) AND CRIP PAPER. SIMULTANEOUSLY INSULATION MAKE CAPACITANCE
- 27. Quartz in CT Reduces the quantity of oil Provides mechanical strength for the conductors Improves the quality of oil by absorbing moisture Being a bad conductor of heat, it allows slow heating /cooling of the CT. Finally expansion tank is attached and after that evacuation of oil and gas filling will be there . There is also one imp term is D3 point which is also called the earth point.
- 28. Thank You