percobaan trafo 1 fasa.docx

MAGNET AND TRAFO CIRCUIT REPORT

1 PHASE TRANSFORMER TEST

CLASS : D3 - I AGROUP : Group 1 RESPONSIBLE PERSON : Niken Endras Camarita / 1131120113MEMBER OF GROUP : 1. Dio Agatha Septiyan / 1131120122

2. Hedy Febriana Puspitasari / 1131120125 3. Karina Monica / 1131120121 4. Mirtha Isnay Samindha / 1131120088 5. Regina Damayanti / 1131120127

ELECTRICAL ENGINEERING STUDY PROGRAMSTATE POLYTECHNIC OF MALANG

2012

A. PURPOSE

a. PURPOSE OF OPEN CIRCUIT TEST

1. Determine the transformer core losses in no load condition when nominal

voltage.

2. Determine the parameters of transformer core losses (Rc and Xm).

3. Comparing the transformer core losses when step up and step down.

4. Determine the effect of sinusoidal source voltage changing toward transformer

core losses.

5. Determine the transformation of number base on the voltage (a).

6. Understanding the function of open circuit test application.

b. PURPOSE OF SHORT CIRCUIT TEST

1. Get the value of the copper losses when nominal current flows.

2. Get a resistance, reactance, and impedance of transformer ( Rek, Xek, Zek).

3. Get impedance voltage and the rate of transformation (a).

4. Determine save guard of transformer.

c. PURPOSE OF TRANSFORMER POLARITY TEST

1. Knowing what is meant by the polarity of the transformer 1phase.

2. Knowing the methods to determine the polarity of the transformer 1 phase.

3. Knowing the function of the polarity of the transformer 1 phase.

d. PURPOSE OF FULL LOAD TEST

1. Determine regulation and efficiency at load condition transformers

2. Determine loses at one phase transformers

3. Compare the efficiency of step up transformers and step down transformers

e. PURPOSE OF PARALLEL TEST

1. Determine the method for paralleling the two transformers or more

2. Find out the characteristic of load test parallel transformers

3. Find out the current distribution at parallel single phase transformers

Im

Ic

I0

∅oo

B. BASIC THEORY

a. BASIC THEORY OF OPEN CIRCUIT TEST

Parameter of transformer core losses can determine with open circuit test and

short circuit test. For open circuit test is :

1. In no load condition, the current flow is too small. Because of it, the copper

losses and reactance transformer can be ignored. So we just measure the

transformer core losses.

2. In no load condition, the source is used nominal voltage so the output is nominal

transformer core losses.

3. In no load condition, if the primary coil connected with voltage source (V1), so Io

will be flow through the primary coil. From the measuring input power (P1),

input current (Io), and input voltage (V1), we can get :

cos∅=P1

V 1 . I 0

I c=I 0cos∅ 0

I m=I 0 sin∅ 0

Rc=V 1

I c

X m=V 1

I m

From measuring in no load test, we can determine Rc and Xm value. The

transformer core losses consist of hysteric losses and eddy current losses and the

transformation number.

a=V 1

V 2

=N1

N2

b. BASIC THEORY OF SHORT CIRCUIT TEST

Short Circuit Test

The short circuit test is performed by short circuiting one of the two

windings, by supplying the other one with a voltage adjustable from zero, until

reaching the value of the rated current of the winding itself. In this test, the

whole absorbed power corresponds to the only copper losses of the two

windings, since, the low applied voltage given (in the short circuit test of the

transformer), the magnetizing current, the flux in the core and the consequent

losses are negligible. In these conditions we determine the equivalent resistance

of the transformer.

Copper Losses

The value of copper losses influenced by :

The quality of email and enamel of transformer.

There are terminal which advers in high voltage side and low voltage side

cause a warming and make copper loses increases.

Measuring Cooper Losses And Impedance

Measuring copper looses have a purpose to know the value of power

losses when trafo work arising out of cooper (WCU) and Strey Lose (WS) of

transformer.

We can measuring cooper looses by give a nominal current in one of side

and the other side shorted, it will arise nominal current in that side, so that the

transformer “as-if” fully loaded.

In short circuit test we need to know in advance the value of In. Aim to

avoid damage (for security). In can be searched by:

PTRAFO = VTR x I

= 48 x 10

= 480

INOM = P

V TT

=480220

= 2,182 2,2 A

In short circuit test, we get the cooper loss, which I in Short Circuit test is

very large so that R is relatively small.

Figure 1. Equivalent Circuit

Explanation :

Nominal current is the reference of the test

At the time of practice should not be too long-time because of the warmingof

transformer and if repeated it will cause chaos to the data obtained because of

the losses.

Short circuit test can also be used to find the transformation rate by

comparison

a =I 2

I 1

Figure 2. Equivalent Circuit when Short Circuit

Explanation:

In equivalent circuit, the core of the transformer is considered non-existent of

be ignored because the current choose to flow in the smaller place.

By measuring the voltage Vhs., Ihs. And Phs., will be calculated parameters :

Rek =

Ph . s

( I h. s )2

Zek =

V h. s

I h. s = Rek+jXek

Xek = √Zek 2−R

ek2

Rek = R1 + R2’

R2 = R2’ / a2

Xek = X1 + X2’

X2 = X2’ / a2

Vz = (VhsVn )X 100%

c. BASIC THEORY OF TRANSFORMER POLARITY TEST

By looking at the way the coils wrapped around the transformer can be

determined the direction of the induced voltage is raised and the polarity of the

transformer. When the primary coil which is a high-voltage coils were tegngan,

twisted way as in figure 1 below will generate the induced voltage as indicated by

respective arrows. This means that the terminal T1 (+) have the same polarity to the

terminal R1 (+), while T2 (-) have the same polarity with R2 (-). Polarity in the form

known as the polarity of the reduction. When the polarity of the T1 (+) = R2 (+) and

T2 (-) = R1 (-), meaning how the low voltage coil wrapped around the R1R2

opposite of figure 2, and this relationship is called the polarity of the sum. ( Zuhal,

Teknik Tenaga Listrik)

Figure 3. Transformer terminals that have been identified

Figure 4. Existing terminal at the transformer

d. BASIC THEORY OF FULL LOAD TEST

Give the secondary side with load and the primary side with voltage. Because the

secondary side are having load, so the current would be flows through both of

transformer coil.

Figure 5. Load transformer equivalent circuit

From the circuit above, we can conclude that :

From that conclusion, we will know that the primary current is a function from the

load current. Controlling the voltage or we called it regulation is drop voltage at

output side in load condition. The aim of regulation is :

Controlling the input voltage to be stabled with load

Controlling the coil to changing the voltage (Tap Changer)

Regulation could be determined by using formula :

Regulation=V no load−V fullload

V full load

× 100 %

In the other side, efficiency is the equivalent between output power and input power

for determine the magnitude of the transformer power and as indicator the

transformer loses.

Efficiency (η )=Poutput

Pinput

× 100 %

From the open circuit test and short circuit test, transformer equivalent circuit at load

condition who had been transformed to the primary side could be replaced like in the

picture below :

Figure 6. Load transformer equivalent circuit from OC test and SC test

If the no load voltage is constant, we can conclude that :

From that equation, we can drawn the phasor diagram for the three load condition,

like this :

Figure 7. Load transformers phasor diagram (a) resistive (b)induktive (c) capasitive

Reactive load characteristic will dominantly affect the voltage magnitude at

secondary transformer. Inductive load characteristic will significantly causes drop

voltage at secondary side (V2). Capasitive load will make the secondary voltage

higher than the primary voltage.

e. BASIC THEORY OF PARALEL TEST

Sometimes, in load condition needs to paralleling the transformers. The main

purpose of paralleling transformers is to make the load each transformers are

proportional with his power ability, so the overload can be minimized.

Figure 8. The right circuit of parallel transformers

Figure 9. The wrong circuit of parallel transformers

For that circuit, we needs some requirement, such as:

1. The transformers have the same voltage ratio (Look in the nameplate)

If the voltage ratio didn’t same, the induction voltage at secondary coil of

each transformer will be not same. This dissimilarity causes the Eddy’s current

at secondary coil in load condition. This current makes the secondary coil warm

up.

2. The transformers have the same polarity (Look at the transformers terminal or

the result of polarities test)

3. The transformers have the same impedance voltage at full load condition (Look

in the nameplate or in the short circuit test)

From equivalent formula we can conclude :

V1 = Z1 Zek + V2’ ................................................................................ (1)

The parallel transformers could be described as :

I1 total = I1A + I1B .................................................................................. (2)

Because,

V1 = I1 Zek + V2’ .................................................................................... (3)

So, for the full load condition:

V1 – V2’ = I1A Z1A = I1B Z1B ..................................................................... (4)

Figure 10. Divider current at parallel transformers

From that formula is meaning that the transformers, to makes the

transformers dividing the current as the Volt-Ampere ability, so the impedance

voltage at load condition must be similarity (I1A x Z1A = I1B x Z1B). Therefore we

can conclude that both of the transformers are having the same impedance unit.

4. The reactance ratio to resistance should be same as (Short circuit test)

If the R/X ratio is same, both of transformers will be working at the same

work factor.

C. PICTURE OF TEST CIRCUIT

a. PICTURE OF OPEN CIRCUIT TEST

Measure tool that used in open circuit test such as :

Voltmeter is to measure the input voltage and output voltage.

Amperemeter is to measure Io

Wattmeter is to measure the transformer core losses.

b. PICTURE OF SHORT CIRCUIT TESTTT TR

Figure 11. Picture of Short Circuit Test

Amperemeter is used to measure I nominal.

Voltmeter is used to measure VSR (short circuit).

Wattmeter is used to measure transformer and load loss.

Ampere is used to measure current in low voltage side.

c. PICTURE OF TRANSFORMER POLARITY TEST

To find out the high voltage (HV) and the low voltage (LV) of a transformer is

carried out experiments as follows:

Figure 12. The series of experiments to determine the coil HV and LV coils

To find out the type of polarity is the polarity of the sum (additive) or reduce

(substraktif).

Figure 13. The series of experiments to determine the type of polarity

To find out the positive and negative terminals of a transformer with certainty by

using a reference transformer.

Figure 14. The series of experiments to determine the positive and negative

terminals of a transformer

d. PICTURE OF FULL LOAD TEST

Figure 15. Full Load Test Circuit

1. V1 = Measuring the input voltage

V3

Blank Transformer

References Transformer

2. A1 = Measuring the current I1

3. W1 = Measuring the input power (transformator and load) 4. A2 = Measuring the current I2 (load current)5. W2 = Measuring the output power (load)6. V2 = Measuring the load voltage

e. PICTURE OF PARALLEL TEST

Figure 16. Parallel Test Circuit

1. V1 = Measuring the input voltage2. A1 = Measuring the current I1

3. A2 = Measuring the current of transformer 14. A3 = Measuring the current of transformer 25. W1 = Measuring the input power (transformator and load) 6. A4 = Measuring the current loa current7. W2 = Measuring the output power (load)8. V2 = Measuring the load voltage

D. TOOLS AND MATERIALS

a. TOOLS AND MATERIALS OF OPEN CIRCUIT TEST

1. 1 phase transformer 220/48V ; 10 A 1 unit

2. 1 phase wattmeter 1 unit

3. Voltmeter 1 unit

4. Ampermeter 1 unit

5. Cable as needed

b. TOOLS AND MATERIALS OF SHORT CIRCUIT TEST

1. 1 Phase Transformer 220 / 48 V ; 10 A 1 unit

2. Voltmeter 1 unit

3. Amperemeter 1 unit

4. Wattmeter 1 Phase 1 unit

5. Ampere pliers 1 unit

6. Cable as needed

c. TOOLS AND MATERIALS OF TRANSFORMER POLARITY TEST

1. Transformator Blank 1 unit

2. Transformator referensi 1 unit

3. Voltmeter 3 unit

4. Miliohmmeter 1 unit

5. Cable as needed

d. TOOLS AND MATERIALS OF FULL LOAD TEST

1. 1 phase transformer 1 unit

2. Voltmeter 2 unit


4. Ohmmeter 2 unit

5. Resistive load (ball-lamp) 4 unit

6. Cable as needed

e. TOOLS AND MATERIALS OF PARALLEL TEST

1. 1 phase transformer 2 unit

2. Voltmeter 2 unit


4. Wattmeter 2 unit

5. Resistive element 1 set

6. Cable as needed

7. Current Transformer 2 unit

E. TEST PROCEDURE

a. TEST PROCEDURE OF OPEN CIRCUIT TEST

1. Calibrating and checking the condition of measure tool.

2. Setting the wattmeter with seri and parallel to measure the transformer core

losses (PFe).

3. Setting the voltmeter with parallel to determine the input voltage.

4. Setting the ampermeter with seri to measure input current.

5. Setting the input voltage in 0V, 10V, 20V, 30V, 48V.

6. Writing down the value that showed by voltmeter, ampermeter, and wattmeter

every the voltage increase.

7. Setting the input voltage in 220V.

8. Writing down the value that showed by voltmeter, ampermeter, and wattmeter.

9. Comparing the transformer core losses when use step up and step down

transformer.

10. Calculating the transformation number base on the voltage.

11. After finish, setting the voltage source in 0V.

b. TEST PROCEDURE OF SHORT CIRCUIT TEST

Safety Procedure

1. Arranging the series according to the picture of short circuit.

2. Re-examining a series of trials before being tested.

3. Reporting the series to the instructure before being tested.

4. Connecting the circuit to the source.

5. Recording the result of the short circuit test

Test Procedure

1. Preparing tools and material of the test.

2. Checking and calibrating the tools to be used.

3. Arranging the series according to the picture of short circuit.

4. Connecting Wattmeter, voltmeter, and amperemeter in the high voltage side

according to the circuit picture.

5. Giving the voltage of the source on the HV side is raised little by little until

the amperemeter read nominal current (2,2 A).

6. Recording the primary input power in Wattmeter, primary nominal current

in amperemeter are already right at 2,2A,input voltage in voltmeter, and the

current which flow in the LV side by using ampere pliers.

7. Recording the measured data of the tools to the table.


c. TEST PROCEDURE OF TRANSFORMER POLARITY TEST

1. Preparing the experimental tools.

2. Checking and calibrating the equipment to be used.

3. Arranging the tools and materials according with Figure 12.

4. Measuring the resistance using miliohmmeter.

5. Recording the results on the gauge reads miliohmmeter in Table 1.

6. Making analysis of the data that has been established to determine the HV & LV

side.


8. Entering the input voltage V1 = 220 V at the HV terminal.

9. Recording the results read on a voltmeter measuring devices in table 2.

10. Determining the type of addition or subtraction polarity, if the data has been

obtained.


12. Entering the input voltage V1 = 220 V on the terminal side of the HV

transformer or transformer reference blank.

13. Recording the results read on a voltmeter measuring devices in table 3 .

14. Determining the transformer terminals is positive or negative blank assisted with

data from previous experiments, if the data has been obtained.


d. TEST PROCEDURE OF FULL LOAD TEST

1. Preparing the used materials.

2. Making the circuit like the picture above.

3. Setting the voltage source up to the nominal voltage.

4. Giving the circuit with varies of load.

5. Write the result of Wattmeter, Voltmeter, and Amperemeter each load.


The load varies :Resistive load (ball lamp) :

a.

b.

c.

d.

Inductive load (Ballast) :

a.

b.

c.

d.

7. Making the analysis and calculating the regulation and efficiency.

e. TEST PROCEDURE OF PARALLEL TEST

1. Preparing the used materials

2. Making the circuit like the picture above

3. Giving the High Voltage side or the secondary side with varies of load

The load varies :

Resistive Load (Ball-lamp) :

a.

b.

c.

d.

4. Setting the voltage source up to the nominal voltage

5. Writing down the result of Wattmeter, Voltmeter, and Amperemeter each load

6. Making the analysis and calculating the regulation and efficiency.


F. TEST RESULT

a. TEST RESULT OF OPEN CIRCUIT TEST

Transformer 1

V1 V2 I0 P1 a

(V) (V) (A) (W)

10 45.2 0.27 3 x 0.4 = 1.2 0.221

20 90 0.36 13 x 0.4 = 5.2 0.222

30 133 0.45 26 x 0.4 = 10.4 0.225

48 215 0.77 62.5 x 0.4 = 25 0.223

220 47.8 0.17 73 x 0.4 = 29.2 4.6

Nominal Input Voltage 48V

cos∅=P1

V 1 × I 0

= 2548× 0.77

=0.68

I C=I 0cos∅=0.77×0.68=0.52

I m=I 0 sin∅=0.77 ×0.73=0.56

RC=V 1

I C

= 480.52

=92.31

X m=V 1

I m

= 480.56

=85.7


cos∅=P1

V 1 × I 0

= 29.2220 × 0.17

=0.78

I C=I 0cos∅=0.17×0.78=0.13

I m=I 0 sin∅=0.17 ×0.63=0.11

RC=V 1

I C

= 2200.13

=1692.31

X m=V 1

I m

= 2200.11

=200 0

Transformer 2

V1 V2 I0 P1 a

(V) (V) (A) (W)

10 50 0.24 3 x 0.4 = 1.2 0.2

20 95 0.33 11 x 0.4 = 4.4 0.21

30 145 0.41 23 x 0.4 = 9.2 0.207

48 230 0.74 57 x 0.4 = 22.8 0.209

220 45 0.13 60 x 0.4 = 24 4.9


cos∅=P1

V 1 × I 0

= 22.848× 0.74

=0.64

I C=I 0cos∅=0.74× 0.64=0.47

I m=I 0 sin∅=0.74 ×0.77=0.57

RC=V 1

I C

= 480.47

=102.13

X m=V 1

I m

= 480.57

=84.2


cos∅=P1

V 1 × I 0

= 24220 × 0.13

=0.84

I C=I 0cos∅=0.13×0.84=0.11

I m=I 0 sin∅=0.13× 0.54=0.07

RC=V 1

I C

= 2200.11

=2000

X m=V 1

I m

= 2200.07

=3142.83

b. TEST RESULT OF SHORT CIRCUIT TEST

No TrafoI1

(A)

V1

(V)P1 (W)

I2

(A)a

Rek

(Ω)Zek

(Ω)

Xek

(Ω)

Vz

(%)

1.Trafo

12,2 14,5

15,5 x 2 = 31

W9,3 4,23 6,4 6,59 1,57 6,6

2Trafo

22,2 12,5 13 x 2 =26 W 9,3 4,23 5,37 5,682 1,851 5,7

3Trafo

42,2 16 17,2 x 2 =

34,4 W9,2 4,18 7,11 7,27 1,54 7,2

Transformer 1

V = 14,5 V ; I = 2,2 A ; P = 15,5 x 2 = 31 W ; ITR = 9,3 A

Z = VI =

14,52,2

= 6,59

R = P

I 2 = 31

2,22 = 6,4

X = √Z2−R2 = √6,592−6,42

= √2,4681

= 1,571

Z% = V hs

V nom x 100%

= 14,5220

x 100%

= 6,6 %

c. TEST RESULT OF TRANSFORMER POLARITY TEST

Table 1. Experiments with the first method

No R sisi HV R sisi LV

Ohm() V Ohm() V

1. 37,89 220 2,30 54

Table 2. Experiment with both methods

No V1

(volt)

V2

(volt)

V3

(volt)

KET

1. 220 54 167,5 Substructive

2. 220 54 271 Additive

Table 3 Experiment The third method

V1 Trafo Refrensi

(Volt)

V2 Trafo Blank

(Volt)

V3

(Volt)

KET

54 48 100 Additive

54 48 5 Substructive

d. TEST RESULT OF FULL LOAD TEST

Step Up Transformer Experiments With Resistive Load

V1 = 48 V

Beban

(W)P1(W) P2(W) Vno load(V) I1(A) V2(V) I2(A) η(%) ∆V(%)

100/100/

200

90 66 230 18,2 212 0,32 73,33 8,49

100 110 98 230 2,8 216 0,5 89,09 6,48

100//

100

200 185 230 4,6 214 0,9 92,5 7,48

100//100

//100

290 260 230 6,0 206 1,28 89,65 11,65

100//100

//100//

200

450 410 230 8,8 200 2 91,11 15

Step Up Tranformer Experiments With Inductive Load

V1 = 48 V

Beban

(W)P1(W) P2(W) Vno load(V) I1(A) V2(V) I2(A) η(%) ∆V(%)

L1//L2 72 38 230 5,9 217 1,25 52,78 5,99

L1//

L2//L3

90,2 51,2 230 7,6 211 1,7 56,67 7,48

L1//

L2//

L3//L4

126 70 230 9,4 213 2,25 55,56 7,98

L1//

L2//

L3//

L4//L5

156 87 230 13,5 212 2,9 55,76 8,49

Step Up Down Transformer Experiments With Resistive Load

V1 = 220 V

Beban

(W)P1(W) P2(W) V1(V) I1(A) V2(V) I2(A) η(%) ∆V(%)

100//200 50 26 45 0,24 40 0,6 52 12,5

The example of efficiency and regulation calculation :

Efficiency

Single transformer efficiency at 100W resistive load


Pinput

× 100 %

¿ 98110

× 100 %

¿89,09 %

Regulation

Single transformer regulation at 100W resistive load


V full load

x 100 %

¿ 230−216216

x100 %

¿6,48 %

e. TEST RESULT OF FULL LOAD TEST

Percobaan Dengan Beban Resistif Menggunakan Trafo Step Up 240 VA

V1 = 48 V

Beban (W)

P1(W)

P2(W)

Vno load(V)I

1(A)V

2(V)I2(A) I3(A) I4(A) η(%) ∆V(%)

100 76 53 230 3,2 225 0,85 2,7 0,42 69,73 2,22

100//

100

235 190 230 4,4 207 1,7 3,6 0,74 80,85 11,11

100//100

//100

305 240 230 6,6 198 2,7 4,4 0,98 78,68 16,16

100//100

//200

450 390 230 8,9 184 4,1 6,6 1,75 86,67 25

Percobaan Dengan Beban Resistif Menggunakan Trafo Step Up 50 VA

V1= 48 V

Beban (W)

P1(W)

P2(W)

Vno

load(V)I1(A)

V

2(V)I2(A) I3(A) I4(A) η(%) ∆V(%)

100 86 74 230 1,75 176 0,9 0,93 0,4 86,05 30,68

The example of efficiency and regulation calculation :

Efficiency

Parallel transformer efficiency at 100W resistive load


Pinput

× 100 %

¿ 5376

×100 %

¿69,73 %

Regulation

Parallel transformer regulation at 100W resistive load


V full load

x 100 %

¿ 230−225225

x100 %

¿2,22 %

G. The chart of the Load and Parallel Test

0 50 100 150 200 250 300 350 400 4500

10

20

30

40

50

60

70

80

90

100

Efficiency Chart

SU single trafo with resistive loadSU single trafo with inductive loadSU parallel trafo with resistive load

Load (W)

Efficie

ncy

(%)

0 50 100 150 200 250 300 350 400 4500

5

10

15

20

25

30

Regulation Chart

SU single trafo with resistive loadSU single trafo with inductive loadSU parallel trafo with resistive load

Load (W)

Regu

latio

n (%

)

percobaan trafo 1 fasa.docx

Documents

open circuit test

short circuit test

short circuit test

100w resistive load

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transformer core losses

full load condition

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