PROIECTAREA UNUI TRANSFORMATOR DE PUTERE DE CONSTRUCŢIE NORMALĂ

UNIVERSITATEA POLITEHNICA TIMI?OARA
FACULTATEA DE ELECTROTEHNIC? ?I ELECTROENERGETIC?

















PROIECT MA?INI ELECTRICE




Student xxx
An xxx














2009













TEMA
PROIECTAREA UNUI TRANSFORMATOR DE PUTERE
DE CONSTRUC?IE NORMAL?







Se va dimensiona un transformator trifazat ?n ulei av?nd urm?toarele date:

 EMBED Equation.3 
 = 350 [kva]
 EMBED Equation.3 
 =  EMBED Equation.3 
  EMBED Equation.3 
 [ EMBED Equation.3 
]
 EMBED Equation.3 
 = 15 [kv]
 EMBED Equation.3 
 = 0,4 [kv]
Gr. de conexiuni =  EMBED Equation.3 

 EMBED Equation.3 
 = 870 [w]
 EMBED Equation.3 
 = 5400 [w]
 EMBED Equation.3 
 = 6 [%]

Miezul se realizeaz? din tole laminate la rece caracterizate prin  EMBED Equation.3 
= 0,55 [w/kg]. ?nf??ur?rile se realizeaz? din aluminiu. Transformatorul se prevede pe partea de ?.T. cu prize ?i comutator de reglare a
tensiunii secundare de ± 5[%].








Dimensiunile miezului

Sec?iunea de fier a coloanei unui transformator trifazat este dat? de rela?ia:
 EMBED Equation.3 
= EMBED Equation.3 
 EMBED Equation.3 

Unde pentru tole laminate la rece :  EMBED Equation.3 
=(2,5 – 4,5)  EMBED Equation.3 
  EMBED Equation.3 

 EMBED Equation.3 
=  EMBED Equation.3 
=  EMBED Equation.3 
=  EMBED Equation.3 
=  EMBED Equation.3 
  EMBED Equation.3 


Induc?ia magnetic? ?n coloanele miezului are valori cuprinse, ?n general ?ntre  EMBED Equation.3 
=1,55 – 1,75 T , pentru tole laminate la rece. Alegem  EMBED Equation.3 
=1.65 T ?i se calculeaz? num?rul de spire al ?nf??ur?rii de joas? tensiune:
 EMBED Equation.3 
= EMBED Equation.3 
 =  EMBED Equation.3 
 =  EMBED Equation.3 
 = 33,04 spire

Se rotunje?te  EMBED Equation.3 
 ?i se recalculeaz?  EMBED Equation.3 
:

 EMBED Equation.3 
 = 33 spire  EMBED Equation.3 
 33 =  EMBED Equation.3 
  EMBED Equation.3 
  EMBED Equation.3 
- EMBED Equation.3 
= EMBED Equation.3 

 EMBED Equation.3 
=  EMBED Equation.3 
 = 1,652370073 T [valoarea adoptat?].

Se stabile?te diametrul cercului circumscris coloanei , care se execut? ?n trepte, cu rela?ia:
 EMBED Equation.3 
 , unde  EMBED Equation.3 
 , respectiv  EMBED Equation.3 
.

 EMBED Equation.3 
 =  EMBED Equation.3 
 =  EMBED Equation.3 
 = 0,170723306 m

Lungimea echivalent? sau “ideal? ?n fier”:
 EMBED Equation.3 
= EMBED Equation.3 
 , unde  EMBED Equation.3 
 ;  EMBED Equation.3 
w ;  EMBED Equation.3 

 EMBED Equation.3 
 ;  EMBED Equation.3 
w/kg ;  EMBED Equation.3 

 EMBED Equation.3 
 =  EMBED Equation.3 
 = 1,802015726

 EMBED Equation.3 
= EMBED Equation.3 
 =  EMBED Equation.3 
 = 3,343439605 m , ?n func?ie de care se pot

calcula lungimea coloanei ?i lungimea jugului cu rela?iile:
 EMBED Equation.3 
 , respectiv  EMBED Equation.3 
 ; ?n care  EMBED Equation.3 
 ?i  EMBED Equation.3 
.
 EMBED Equation.3 
 =  EMBED Equation.3 
 =  EMBED Equation.3 
 = 0,648727087 m
 EMBED Equation.3 
 =  EMBED Equation.3 
0,648727087 = 0,908217921 m

Sec?iunea jugului rezult?:  EM...