Se ha denunciado esta presentación.
Utilizamos tu perfil de LinkedIn y tus datos de actividad para personalizar los anuncios y mostrarte publicidad más relevante. Puedes cambiar tus preferencias de publicidad en cualquier momento.

0 Presentation1

452 visualizaciones

Publicado el

  • Sé el primero en comentar

0 Presentation1

  1. 1. PRESENTATION ON TRANSFORMER CONSTRUCTION Presented by Rakesh Kumar Reg. no. 11011752
  2. 2. Transformer An A.C. device used to change high voltage low current A.C. into low voltage high current A.C. and vice-versa without changing the frequency In brief, 1. Transfers electric power from one circuit to another 2. It does so without a change of frequency 3. It accomplishes this by electromagnetic induction 4. Where the two electric circuits are in mutual inductive influence of each other.
  3. 3. Principle of operation It is based on principle of MUTUAL INDUCTION. According to which an e.m.f. is induced in a coil when current in the neighbouring coil changes.
  4. 4. Constructional detail : Shell type • Windings are wrapped around the center leg of a laminated core.
  5. 5. Core type • Windings are wrapped around two sides of a laminated square core.
  6. 6. Working of a transformer 1. When current in the primary coil changes being alternating in nature, a changing magnetic field is produced 2. This changing magnetic field gets associated with the secondary through the soft iron core 3. Hence magnetic flux linked with the secondary coil changes. 4. Which induces e.m.f. in the secondary.
  7. 7. Three-Phase Transformers Construction • A three-phase transformer is constructed by winding three single-phase transformers on a single core. • Three-phase transformers are connected in either wye or delta configurations.
  9. 9. (i). Oil The oil helps cool the transformer. Because it also provides part of the electrical insulation between internal live parts, transformer oil must remain stable at high temperatures for an extended period. To improve cooling of large power transformers, the oil-filled tank may have external radiators through which the oil circulates by natural convection. (ii). Conservator The transformer conservator acts as a barrier to separate undesirable elements in the atmosphere, such as water vapor, nitrogen, ozone and oxygen, from transformer oil within a conservator. This barrier also reduces condensation and oxidation inside the transformer and suppresses gas bubble formation in the transformer oil.
  10. 10. (ii) Breather a) The plug at the end of the breather pipe is to be removed and breather fitted on to the pipe along with the fly nut. b) It is necessary before fitting the breather to observe the color of the silica-gel. If necessary, the breather should be opened and the silica-gel properly dried up so that its color is perfectly bluish. c) The chamber at the bottom of the breather should be filled in with dry transformer oil up to the level marked. (iv) explosion vent In case an equalizer pipe connection is provided, the valve in the pipe should be kept in open position before the transformer is energized.
  11. 11. (v)shut off valve This should always be in fully open position while the transformer is being energized. (vi) Transformer tank a) Open the air release device on the inspection cover and also on the tank cover to ensure that there is no air trapped inside the tank. b) Gently open the nuts at the bottom of each HV bushings one by one and shake the stud gently until oil starts coming down. Then tighten the nuts properly. All bushings should be kept clean.
  12. 12. Transformer with conservator and breather
  13. 13. DISTRIBUTION TRANSFORMER • TRANSFORMER WHICH IS USED FOR THE PURPOSE OF DISTRIBUTION OF POWER. • 11KV/433V is the standard voltage rating. • STANDARD KVA ratings are 25,63,100,160,200,250,315,400,500,630,750 , 1000,1250,500,2000,2500 KVA. IS-2026 is the NATIONAL IS STANDARD.
  14. 14. Power transformer • Power transformer construction like as three phase distribution transformer. But it bigger in size than three phase distributed transformer. we construct the 3150 KVA power transformer. it is use to step down the voltage. It step down voltage is 33/11KV. • The winding connection of power transformer either star or delta connection.
  15. 15. .LOSSES IN TRANSFORMER All transformers have copper and core losses, and flux leakage. Copper loss is ohmic power lost in the primary and secondary windings of a transformer due to the ohmic resistance of the windings. Copper loss, in watts, may be found using the following equation Copper Loss = IP 2 RP+ IS 2 RS Core losses are caused by two factors: hysteresis and eddy current losses. Hysteresis loss is that energy lost by reversing the magnetic field in the core as the magnetizing AC rises and falls and reverses direction. Eddy current loss is a result of induced currents circulating in the iron core.
  16. 16. TRANSFORMER REGULATION Loading changes the output voltage of a transformer. Transformer regulation is the measure of such a deviation. Definition of % Regulation { ( Vno-load -V load )/V load }*100 % Vno-load =RMS voltage across the load terminals without load V load = RMS voltage across the load terminals with a specified load.
  17. 17. %100 in out P P  %100   lossout out PP P  . EFFICIENCY OF TRANSFORMER Transformer efficiency is defined as (applies to motors, generators and transformers): All day efficiency All day efficiency is of 24 hour. hours)24( kWhinInput kWhinoutput in wattsinput in wattsputout efficiencycommercialordinary day forall   
  18. 18. Applications of Transformers • Transformers have many applications in power transmission and electronics: • They may be used to minimise energy losses due to voltage drop in transmitting electricity over long distances. • They match loads with internal resistance so that there is maximum power transfer. • They couple signals between electronic stages.