transformer design 2b

8/8/2019 Transformer design 2b

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NEW ERA UNIVERSITYCOLLEGE OF ENGINEERING AND TECHNOLOGY

ELECTRICAL ENGINEERING DEPARTMENT

EE 552D

ELECTRICAL MACHINE DESIGN

W: 10:00AM 1:00PM

DESIGN II B

DESIGN OF MAGNETIC CIRCUIT OF DISTRIBUTION TYPE TRANSFORMER

(FROM ITEM 24 TO ITEM 32)

NAME: Molina,Gillian S. RATING:

COURSE: BSEE DATE OF START: SEP 13,

DOS: SEP 22, 2010

ENGR. REYNALDO DELA CRUZ

INSTRUCTOR


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I. OBJECTIVES1. To have preliminary calculations of winding design of primary and secondary

item 1 up to item 23.

2. To determine the final data of the primary an secondary winding design.II. EQUIPMENT NEEDED

1-calculator

1-design book manual

1-laptop or computer

1-other reference book

III. PROCEDURESItem 1: Itis proposed to design a core type transformer with rectangular coils.

A subsequentdesign, Art. 147, will be devoted to the calculation of a cruciform-

coretype of

transformer.

Description . This is a distribution transformer of standard type for maximum

outputrating. Itis oil immersed and self cooling, withouttape for voltage

adjustment.

Insulation tests(in tank with oil) ; voltage applied for 1 min

H.T. winding to L.T. winding and core, 10,000 volts

L.T. winding to core, 4,000 volts

The specified temperature rise of 55rC means that the temperature of the

windings, as measured by the resistance method, after the transformer has been

operating continuously at full load, will not be more than 55rC above the

temperature of the surrounding air.

Item 33. By the formula the efficiencies at unity factor are :

At full load , 1-36.6 + 92..3

5 000 + 129.2= 0.9748

At half=load, 1-36.9 + 23.1

2 500 + 60 = 0.9766

The calculated values for other loads are:

At 25 percent overload, 0.9718

At full load, 0.9769

At full load, 0.9668

The maximum efficiency occurs when the total copper losses are equal to the

core loss, under which condition the fraction of rated load is.


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V. DATA AND RESULTItem

No.

Summary of Calculation

24.25.

26.

27.

28.

29.

30.

31.

32.

Dimension of window, in..Total flux, maxwells...

Flux density in core under windings, lines per

sq in..

Cross section of iron in core under windings,

in2

Width of stamping in core under windings, in.

Gross thickness of core, in

Watts loss in iron (compare with guarantee),lbs..

Total wt. of iron in core, lbs.

Total full load losses,

watts

16 1/4 x 5 1/21,000,000

85,000

41

4 1/2

619.84

268.22269.206

1036

Design Calculation


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Item No. 24: Dimension of Window, in

11 1/2 x 61/4

Item No. 25: Total Flux, maxwells

1,000,000 Maxwells

Item No. 26: Flux density in core under winding.

Bg = 85,000 Lines/in2

Item No. 27: Cross section of iron in core under winding.

= 0.9 (S x L) = 0.9x38.32x19.16

= 660 in.

Item No. 28: Width of stamping in core under windings.

L=4.5 or 4 in

Item No. 29: Gross thickness of core

S =38.32 in

Item No.30: Total wt. of iron in core

Wt of iron = 0.28(SFxSxM) x2 (H+M+S+L)

= 0.28(0.9 x 19.16 x 38.32) x2(5.145+10.16+38.32+38.32)

= 843.84 lbs.

Item No. 31: Wattss loss in iron (compare w/ guarantee)

Watts/lbs = 268.22 watts

Item No. 32 Total Full load losses, watts

= 268.22 + .986 = 269.206 watts

VI. GRAPH AND TABLE


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VII. REMARKS

VIII. CONCLUSIONTherefore I conclude that in this design of magnetic circuit it is very difficult

because of they have a less complex or variable. Thus also I conclude that the

emf voltage induced by the alternating flux in the primary and secondary coils will

be directly proportional to the number of turns in the perspective windings.

transformer design 2b

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