percobaan trafo 1 fasa.docx

MAGNET AND TRAFO CIRCUIT REPORT 1 PHASE TRANSFORMER TEST

CLASS GROUP

: D3 - I A : Group 1

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 copp er losses when nominal current flows. 2. Get a resistance, reactance, and impedan ce of transformer ( R ek  ek , Xek , Zek ). 3. Get impedance voltage and the rate of transformation (a). 4. Determine save guard of transformer.

c.

PURPOSE OF TRANSFORMER POLARITY TEST

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 :

 

  I0

Im

       

Ic



o

 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 (W CU) and Strey Lose (WS) of 

In short circuit test, we get the cooper loss, which I in Short Circuit test is very large so that R is relatively small.

W Rek

Xek

Isc

V

A

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

V h . s



Zek =



Xek =



R ek = R 1 + R 2’



R 2 = R 2’ / a



Xek = X1 + X2’



X2 = X2’ / a



Vz =

 I h . s

= R ek +jXek 

 Z ek 

2

 Rek 

2

2

2

   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

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.

X1

X2

R1

V1

R2

R0

X0

RB

V2

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 :

          

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.

()    

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 :

 I 2 '

I2 / a



From that equation, we can drawn the phasor diagram for the three load condition, like this : V1 a

jX.I2' I2'

V2' R.I2' V1

 b jX.I2' I2'

V2'

R.I2' V1

c

jX.I2' I2' V2'  b

a

c

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

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)

I1 total = I1A + I1B .................................................................................. (2) Because, V1 = I1 Zek + V2’ .................................................................................... (3) So, for the full load condition: V1 – V2’ = I1A Z1A = I1B Z1B ..................................................................... (4)  I 1 A

 Z 1 B

 I 1 total 

V 1

 I 1 B

 Z 1 A

V 2 '

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.

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 TEST

TT  A

TR 

W

V

ohm

ohm

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). V3

 A

V1 B

C

V2 D

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

d. PICTURE OF FULL LOAD TEST LV

W1

HV

A1

~

A2

W2

V1

zLOAD

V2

Figure 15. Full Load Test Circuit 1. 2. 3. 4. 5. 6.

e.

V1 = Measuring the input voltage A1 = Measuring the current I1 W1 = Measuring the input power (transformator and load) A2 = Measuring the current I2 (load current) W2 = Measuring the output power (load) V2 = Measuring the load voltage

PICTURE OF PARALLEL TEST

W1

A1

A2

LV +

HV +

 A4

W2 L

~

V1

V2

O  A D

-

-

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

c.

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

TOOLS AND MATERIALS OF TRANSFORMER POLARITY TEST

e.

TOOLS AND MATERIALS OF PARALLEL TEST 1. 1 phase transformer

2 unit

2. Voltmeter

2 unit

3. Amperemeter

4 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.

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

c.

TEST PROCEDURE OF TRANSFORMER POLARITY TEST 1. Preparing the experimental tools. 2. Checking and calibrating the equipment to be used.

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

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. 6. After finish, setting the voltage source in 0V. The load varies : Resistive load (ball lamp) : 100 W

100 W

d.

Inductive load (Ballast) :

a.

100 W

100 W

200 W

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) :

100 W

100 W

100 W

100 W

200 W

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



 Nominal Input Voltage 220V

                                              

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



 Nominal Input Voltage 220V

                                               b. TEST RESULT OF SHORT CIRCUIT TEST

No

1.

2

Trafo

Trafo 1 Trafo 2

I1

V1

(A)

(V)

2,2

14,5

2,2

12,5

P1 (W)

15,5 x 2 = 31 W

13 x 2 =26 W

I2

(A)

a

Xek 

R ek  (Ω)

Zek  (Ω)

(Ω)

Vz (%)

9,3

4,23

6,4

6,59

1,57

6,6

9,3

4,23

5,37

5,682

1,851

5,7

= 1,571 

 x 100%   x 100% = 

Z% =

= 6,6 %

c.

TEST RESULT OF TRANSFORMER POLARITY TEST Table 1. Experiments with the first method R sisi HV

R sisi LV

No

1.

Ohm( )

V

Ohm( )

V

37,89

220

2,30

54

Table 2. Experiment with both methods No

V1

V2

V3

KET

d. TEST RESULT OF FULL LOAD TEST

Step Up Transformer Experiments With Resistive Load

V1 = 48 V Beban

P1(W)

P2(W)

Vno load(V)

I1(A)

V2(V)

I2(A)

η(%)

∆V(%)

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//

200

185

230

4,6

214

0,9

92,5

7,48

290

260

230

6,0

206

1,28

89,65

11,65

450

410

230

8,8

200

2

91,11

15

(W) 100/100/ 200

100 100//100 //100 100//100 //100// 200

L1//L2//

156

87

230

13,5

212

2,9

55,76

8,49

L3//L4// L5

Step Up Down Transformer Experiments With Resistive Load

V1 = 220 V Beban (W) 100//200

P1(W)

P2(W)

V1(V)

I1(A)

V2(V)

I2(A)

η(%)

∆V(%)

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

()        

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)

I1(A )

V2( 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//

235

190

230

4,4

207

1,7

3,6

0,74

80,85

11,11

305

240

230

6,6

198

2,7

4,4

0,98

78,68

16,16

450

390

230

8,9

184

4,1

6,6

1,75

86,67

25

100 100//100 //100 100//100 //200

Percobaan Dengan Beban Resistif Menggunakan Trafo Step Up 50 VA

V1= 48 V



Regulation Parallel transformer regulation at 100W resistive load

           

       

G. The chart of the Load and Parallel Test

Efficiency Chart 100 90 80 70     )    %     (    y    c    n    e    i    c    i     f     f    E

60 SU single trafo with resistive load

50

SU single trafo with inductive load

40

SU parallel trafo with resistive load 30 20 10 0 0

50

100

150

200

250

Load (W)

300

350

400

450