# Ee Practical in PDF

August 26, 2017 | Author: hussainsaifee | Category: Inductor, Capacitor, Electrical Impedance, Ac Power, Electrical Network

#### Description

Vidharbha Youth Welfare Society’s

Prof Ram Meghe College of Engineering and Management New Express Highway, Badnera – Amravati

First Year Engineering Department

CERTIFICATE This is certify that Mr./Miss______________________________________________________________ Class Roll No.________________ Section__________________ has attended the practical classes and completed the practical work satisfactorily in ________________________________________________ for __________________semester and __________________group as prescribed by Sant Gadge baba Amravati University, Amravati during the year ____________________ with grade__________________

Date:

Prof. Incharge

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

Vidharbha Youth Welfare Society’s

Prof Ram Meghe College of Engineering and Management New Express Highway, Badnera – Amravati INDEX Sr.No.

Name of Experiment

1

___________________________________________________

2

___________________________________________________

3

___________________________________________________

4

___________________________________________________

5

___________________________________________________

6

___________________________________________________

7

___________________________________________________

8

___________________________________________________

9

___________________________________________________

10

___________________________________________________

11

___________________________________________________

12

___________________________________________________

13

___________________________________________________

14

___________________________________________________

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Date

Remarks

Page 2

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

EXPERIMENT NO. 1

AIM:

Verification of Kirchhoff’s laws.

SIGNIFICANCE: These laws are applicable in the analysis of almost all the electrical and electronic circuits. APPRATUS:

1) 2) 3) 4) 5)

Connecting wires, 4mm patch cords, Kirchhoff’s laws kit, Digital Multimeter – 3 nos. Regulated DC power supplies

THEORY: THE KIRCHHOFF’S VOLTAGE LAW It states that “the algebric Sum of all the voltages aroud closed loop is zero”. IR DROP:- Whenever we move in the direction of current there is a drop in voltage, since the current always flows from point at higher potential to the point at lower potential. Hence Voltage drop in the current direction is taken as negative and vice- versa. SIGN CONVENTIONS: If we move from negative terminal of source to positive terminal, there is a voltage rise. Therefore it is to be considered positive. If we move from +ve terminal to –ve terminal of voltage source, there is voltage drop. Therefore it is to be considered as –ve. B) THE KIRCHHOFF’S CURRENT LAW (KCL) It states that “At any instant the algebraic sum of all the currents entering or leaving a node is zero”. A node is a common point in a circuit where more than one elements are connected. If we are going to assign negative sign to the incoming current then we will have to assign positive sign to the outgoing current and vice-versa.

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 3

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

CIRCUIT DIAGRAM: Kirchhoff’s Voltage Law:

Kirchhoff’s Current Law:

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 4

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

SPACE FOR CIRCUIT DIAGRAM (IF THERE IS CHANGE IN DIAGRAM GIVEN ABOVE):

PROCEDURE: A) For Kirchhoff’s Voltage law: 1) Connect the power supply cord of the kit to the socket. 2) Connect variable dc source in the circuit 1 of Kirchhoff’s voltage law. 3) Switch on the supply and measure voltage across all the three resistances i.e R1, R2, and R3 with the help of multimeter of figure 1. Also find out the polarity across each resistor i.e whether there is a voltage rise or voltage drop and mark the positive and negative sign sign across each resistor. This you can done with the help of multimeter, if the meter displays reading without any sign that means the point at which red wire has been connected is positive and point at which black wire has been connected is negative. And if the meter displays reading with negative sign before it that means, the point at which red wire has been connected is at negative and the point at which black wire has been connected is at positive. So, now mark the positive and negative signs across each resistors in the circuit diagram. 4) Note down the readings of voltages across all the resistors in the observation table. 5) Note down 3 more readings in the same manner as described above by varying the supply voltage level. 6) Verify kirchhoff’s voltage law for one or two readings, by writing down KVL equation and verify it in the space provided for calculations. PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 5

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

B) For Kirchhoff’s Current law: 1) Connect the power supply cord of the kit to the socket. 2) Connect variable dc source in the circuit 2 of Kirchhoff’s current law. 3) Switch on the supply and measure current through all the three resistances i.e R1, R2, and R3 or through all the three branches with the help of multimeter(for this set multimeter on 10A range). Also find out the direction of current through each resistors. This you can done with the help of multimeter, if the meter displays reading without any sign that means that the current is flowing from red to black wire or in the direction of red to black. And if the meter displays reading with negative sign before it that means, the current is flowing from black to red wire or in the direction of black to red. Mark the direction of current in the figure 2 by arrow in that branch in the direction of current 4) Note down the readings of current through all the resistors in the observation table. 5) Note down 3 more readings in the same manner as described above by varying the supply voltage level. 6) Verify kirchhoff’s current law for one or two readings, by writing down KCL equation and verify it in the space provided for calculations.

OBSERVATIONS: For KVL:

S.N

Voltage across source, Vs (V)

Voltage across R1, V1 (V)

Voltage across R2, V2 (V)

Voltage across R3, V3 (V)

1 2 3 4

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 6

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

For KCL:

S.N

Current through R1, I1 (A)

Current through R2, I2 (A)

Current through R3, I3 (A)

1 2 3 4 SPACE FOR OBSERVATIONS (IF THERE IS CHANGE IN OBSERVATIONS GIVEN ABOVE):

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 7

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

CALCULATIONS:

RESULTS/CONCLUSION: _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ PRECAUTIONS: _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 8

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

EXPERIMENT NO. 2

AIM:

Verification of Superposition Theorem.

SIGNIFICANCE:

APPRATUS:

Network theorems are used to speed up the analysis of circuits. This theorem is very useful in the analysis of electric circuits containing more than one source. 1) 2mm Patch cords, 2) Digital Multimeter, 3) Superposition Theorem Kit.

THEORY: Statement: Superposition theorem states that "In any linear bilateral network containing two or more sources, the response in any element is equal to the algebraic sum of the responses caused by individual sources acting alone, while the other sources are non-operative i.e., while considering the effect of individual sources, other ideal voltage sources and ideal current sources in the network are replaced by short circuit and open circuit across their terminals”. EXPLANATION: 1. Select only one source and replace all other sources by there internal resistances. (If the source is the ideal current source replace it by open ckt. if the source is the ideal voltage source replaces it by short ckt.) 2. Find the current and its direction through the desired branch. 3. Add all the branch currents according to their direction to obtain the actual branch current.

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 9

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

CIRCUIT DIAGRAM: FOR BRANCH c-d:

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 10

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

FOR BRANCH e-f:

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 11

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

SPACE FOR CIRCUIT DIAGRAM (IF THERE IS CHANGE IN DIAGRAM GIVEN ABOVE):

PROCEDURE: For branch c-d: 1) Connect the power supply cord of the kit in the socket. 2) Connect 12 V source in branch a-b i.e +12V at upper point and ground at the lower point in branch a-b with the help of 2mm patch cords. 3) Connect 5 V source in branch g-h i.e +5V at upper point and ground at the lower point in branch g-h with the help of 2mm patch cords. 4) Now short the open path in branch e-f with the help of patch cord. 5) Connect milliammeter in branch c-d. 6) Switch on the supply and note down the value and direction of the current in branch c-d. Mark this direction in the diagram. This current will be Icd 7) Now replace 12 V source with a short with patch cord and keep only 5 V source active. Again measure the value and note down direction of current in the branch c-d. this current will be Icd’. If the direction of current changes mark the direction same as before but note down reading with negative sign (draw another diagram for this condition). 8) Now connect 12 V source in the circuit replace 5 V source with a short. Again measure the value and note down direction of current in the branch c-d. this current will be Icd’’. If the direction of current changes mark the direction same as before but note down reading with negative sign (draw another diagram for this condition). 9) Take the algebraic summation of Icd’ and Icd’’ and compare it with Icd, both the values should come same. Do the calculation and verify superposition theorem.

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 12

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

For branch e-f: Repeat the procedure as written above for branch e-f. for this connect milliammeter in the branch e-f and short the branch c-d.

OBSERVATIONS:

Condition

Current flowing through branch c-d

Current flowing through branch e-f

When both the sources are acting

Icd = _______

Ief =_______

When only 5V source is acting

Icd’ =_______

Ief’ =_______

When only 12V source is acting

Icd’’ =_______

Ief’’ =_______

SPACE FOR OBSERVATIONS (IF THERE IS CHANGE IN OBSERVATIONS GIVEN ABOVE):

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 13

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

CALCULATIONS:

RESULTS/CONCLUSION: _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ PRECAUTIONS: _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 14

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

EXPERIMENT NO. 3

AIM:

Verification of Thevenin’s Theorem.

SIGNIFICANCE:

APPRATUS:

Network theorems are used to speed up the analysis of circuits. This is very important theorem for analyzing circuits. 1) 2mm Patch cords, 2) Digital Multimeters, 3) Superposition Theorem Kit.

THEORY: STATEMENT: It states that any linear active two terminal network containing resistance and voltage sources and /or current sources can be replaced by single voltage source VTH in series with a single resistance RTH. The thevenin equivalent voltage VTH is the open circuit voltage at the network terminals, and thevenin resistance RTH is the resistance between the network terminals when all the sources are replaced by their internal resistances. EXPLANATION: a) Steps to find the RTH • Open circuit current sources and short circuit voltage sources. • Open circuit the load resistance • Find out the equivalent resistance which is RTH across the open circuit terminals. b) Steps to find the VTH • Open circuit the load resistance • Find out the open circuit voltage VTH across the open circuit terminals by using mesh analysis. c) Find out the load current IL by connecting the load resistance to the given circuit. d) Draw the equivalent circuit. Connect the voltage source VTH in series with RTH and RL .

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 15

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

CIRCUIT DIAGRAM:

THEVENIN’S EQUIVALENT DIAGRAM:

SPACE FOR CIRCUIT DIAGRAM (IF THERE IS CHANGE IN DIAGRAM GIVEN ABOVE):

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 16

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

PROCEDURE:

1)

Set the value of RL at one fixed value in both original and thevenin’s equivalent network same and equal. 2) Connect +12V, DC power supplies at their indicated position using patch cords. 3) Measure voltage between terminals 2 & 4 using voltmeter, for this connect terminal 2 to the + terminal of DC Voltmeter and 4 to –ve terminal. It is the required practical value of Thevenin's equivalent voltage (VTH). 4) Disconnect the patch cord between terminals 1 to +12V and Gnd to Gnd. 5) Connect test point 1 & Gnd (of circuit) so as to replace source by its internal resistance (assuming it negligible). 6) Measure resistance between terminals 2 & 4 using multimeter. It is the required practical value of Thevenin's equivalent resistance RTH. 7) Connect a 2mm patch cord between terminals 1 and supply and Gnd to Gnd socket. 8) Connect an ammeter between terminals 2 and 3 to measure load current IL flowing through load resistance of original circuit. 9) Now connect 2 mm patch cords between +5v supply and terminal 5 of thevenin’s equivalent network and ground to ground. 10) Connect milliammeter between terminals 6 and 7 of equivalent network and measure the load current IL flowing through load resistance RL of thevenin’s equivalent network. 11) Compare load current (IL) flowing through both of the load resistances and also with the theoretical values of IL calculated.

OBSERVATIONS:

1) 2) 3) 4) 5) 6) 7) 8) 9)

Value of RL set in original and thevenin’s equivalent network = ________ Practical measured value of VTH = __________ Practically measured value of RTH = __________ Practical value of IL measured from original network = ___________ Practical value of IL measured from thevenin’s equivalent network = ___________ Theoretically calculated value of RTH = ________ Theoretical calculated value of VTH = ________ RL set (this same value should be used in theoretical calculations) = _______ Theoretically calculated value of IL = ________

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 17

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

SPACE FOR OBSERVATIONS (IF THERE IS CHANGE IN OBSERVATIONS GIVEN ABOVE):

CALCULATIONS:

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 18

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

RESULTS/CONCLUSION: _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ PRECAUTIONS: _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 19

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

EXPERIMENT NO. 4

AIM: SIGNIFICANCE:

APPRATUS:

Verification of Maximum Power Transfer Theorem. Network theorems are used to speed up the analysis of circuits. This is very important theorem for analyzing amplifier electronic circuits.

1) 2mm Patch cords, 2) Digital Multimeters, 3) Superposition Theorem Kit.

THEORY: DC Circuit:

The maximum power transfer theorem states that “maximum power is delivered from a source resistance to a load resistance when the load resistance is equal to the thevenin’s resistance as seen from load terminals.” RTH = RL is the condition required for maximum power transfer. AC Circuit:

a. The maximum power transfer theorem states that maximum power is delivered from a source impedance to load impedance when the load impedance is equal to the complex conjugate of the thevenin’s impedance as seen from load terminals. b. The maximum power transfer theorem states that maximum power is delivered from a source impedance to load resistance when the load resistance is equal to the magnitude of the thevenin’s resistance as seen from load terminals.”

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 20

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

CIRCUIT DIAGRAM:

SPACE FOR CIRCUIT DIAGRAM (IF THERE IS CHANGE IN DIAGRAM GIVEN ABOVE):

PROCEDURE:

1) 2)

Connect +12V, DC power supplies at their indicated position using patch cords. Measure voltage between terminals 2 & 4 using voltmeter, for this connect terminal 2 to the + terminal of DC Voltmeter and 4 to –ve terminal. It is the required value of Thevenin's equivalent voltage (VTH). 3) Disconnect the patch cord between terminals 1 to +12V and Gnd to Gnd. PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 21

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

4)

Connect test point 1 & Gnd (of circuit) so as to replace source by its internal resistance (assuming it negligible). 5) Measure resistance between terminals 2 & 4 using multimeter. It is the required value of Thevenin's equivalent resistance RTH. 6) Switch off the kit and set the value of RL less than RTH by connecting ohmmeter (multimeter) between terminals 2 and 3. 7) Now connect ammeter (multimeter) between terminals 2 and 3, voltmeter between terminals 3 and 4 and measure value of IL and VL. Also calculate RL and power for this reading. 8) Now increase RL such that it should become more than what we calculated in step 7 but less than RTH, this is going to be second reading. Once again read values of VL and IL from multimeter and calculate RL and power. 9) Now set RL = RTH with the help of multimeter. And measure value of VL and IL and also calculate power for this reading. 10) Increase RL now it will become greater than RTH, note down reading of VL and IL and calculate RL and power for this reading. 11) Further Increase RL , note down reading of VL and IL and calculate RL and power for this reading. 12) Find out value of RL at which maximum power is getting transferred to load. OBSERVATIONS:

S.N

Power PL (mW)

1 RL < RTH 2 3

RL = RTH

4 RL > RTH 5

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 22

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

SPACE FOR OBSERVATIONS (IF THERE IS CHANGE IN OBSERVATIONS GIVEN ABOVE):

CALCULATIONS:

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 23

ELECTRICAL ENGINEERING PRACTICAL

GRAPHS:

GROUP B

Draw graph between load resistance RL on X-axis and power on Y-axis

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 24

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

RESULTS/CONCLUSION: _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ PRECAUTIONS: _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 25

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

EXPERIMENT NO. 5 AIM:

Verification of line and phase relationship of current and voltage in a balanced Star connected load.

SIGNIFICANCE: APPRATUS:

1) 2) 3) 4) 5) 6)

Connecting wires, A.C Voltmeter (0-600V) – 3no. A.C Voltmeter (0-300V) – 3no. Ammeter MI (0-5A) – 3no. Three phase autotransformer – 1no. Rheostat (5A, 100Ω) – 3nos.

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 26

ELECTRICAL ENGINEERING PRACTICAL

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

GROUP B

Page 27

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

CIRCUIT DIAGRAM:

SPACE FOR CIRCUIT DIAGRAM (IF THERE IS CHANGE IN DIAGRAM GIVEN ABOVE):

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 28

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

PROCEDURE: 1) Connect the circuit as shown in figure. 2) Connect the meters of proper ratings. 3) Initially keep the autotransformer at zero position. Then gradually increase the voltage and look at reading of current in all the three ammeters. If current is different change the load in each phase accordingly and bring current in all the three meters equal. This is the balanced condition means now load is balanced. Now don’t change the position of load throughout the experiment. 4) Note down the readings of all the meters in observation table. 5) Now change the voltage level by changing autotransformer position and again note down reading of all the meters. 6) Take 5 to 6 readings like this. 7) Do the calculations and verify relationship between line and phase voltages and current in star connected load. 8) Draw the graph for at least two readings.

S.N VRN (V)

VYN (V)

VBN (V)

VRY (V)

VYB (V)

VYB (V)

Ratio between line and phase voltages

IR (A)

VRY/ VRN

IY (A)

IB (A)

VYB/ VBN

VYB/ VRY

1 2 3 4 5 6

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 29

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

SPACE FOR OBSERVATIONS (IF THERE IS CHANGE IN OBSERVATIONS GIVEN ABOVE):

CALCULATIONS:

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 30

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

GRAPHS:

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 31

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

ii)

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 32

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

iii)

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 33

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

RESULTS/CONCLUSION: _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ PRECAUTIONS: _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 34

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

EXPERIMENT NO. 6 AIM: Verification of line and phase relationship of current and voltage in a balanced Delta connected load. SIGNIFICANCE: APPRATUS:

1) 2) 3) 4) 5) 6)

Connecting wires, A.C Voltmeter (0-600V) – 3no. Ammeter MI (0-10V) – 3no. Ammeter MI (0-5A) – 3no. Three phase autotransformer – 1no. Rheostat (5A, 100Ω) – 3nos.

Page 35

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

Hence, for a delta connected system with balanced load, the magnitude of line currentand of phase current are related as IL = √3Iph From figure, it is obvious that the line voltage VRY is same as the phase voltage VR’R. hence, for a delta connected system, we have VL = Vph

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 36

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

CIRCUIT DIAGRAM:

SPACE FOR CIRCUIT DIAGRAM (IF THERE IS CHANGE IN DIAGRAM GIVEN ABOVE):

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 37

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

OBSERVATIONS: S.N

IY (V)

IB (V)

IRY (V)

IYB (V)

VRY

VYB

VBR

Ratio between line and phase voltages IRY / IR

IYB / IY

IYB / IB

1 2 3 4 5 6

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 38

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

SPACE FOR OBSERVATIONS (IF THERE IS CHANGE IN OBSERVATIONS GIVEN ABOVE):

CALCULATIONS:

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 39

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

GRAPHS: i)

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 40

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

ii)

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 41

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

iii)

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 42

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

RESULTS/CONCLUSION: _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ PRECAUTIONS: _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 43

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

EXPERIMENT NO. 7

AIM:

Study of series R-L-C circuit.

SIGNIFICANCE: APPRATUS:

1) 2) 3) 4) 5)

Connecting wires, A.C Voltmeters (0-300V) – 1 no. A.C Ammeter (0-5A) – 1 no. Wattmeter (10A, 300V) – 1 no. A.C Voltmeters (0-300V) – 3 no.

THEORY: An a.c voltage of r.m.s value ‘V’ when applied to a R-L-C series circuit establishes an r.m.s current ‘I’ given by I = V/Z, where Z = √R² + (XL - XC)² The circuit is as shown in figure 1 and the phasor diagram in figure 2, for the case when XL > XC. The effect of XL > XC is a lagging power factor, since the current I lags behind voltage V by an angle Ф, Where Ф = tan^-1 ((XL –XC/R)) If XC > XL then the power factor of the circuit is leading and current I leads the voltage V by an angle Ф. In an inductor, the copper losses take place due to resistance of its coil, and the core losses take place in the magnetic core (in case of ‘ironed cored’ inductors). In the capacitor, the losses take place in the dielectric medium used for making it.

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 44

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

CIRCUIT DIAGRAM:

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 45

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

SPACE FOR CIRCUIT DIAGRAM (IF THERE IS CHANGE IN DIAGRAM GIVEN ABOVE):

PROCEDURE: 1) Connect the circuit as shown in figure. Connect resistor, inductor and capacitor in series. Keep the resistor, inductor and capacitor at one position. 2) Initially keep the autotransformer at zero position. Now gradually increase the voltage and bring it upto one level. 3) Note down the readings of current, voltages across resistor, inductor and capacitor, applied voltage and also note down power. 4) Now change the value of resistance or inductance or capacitance or all in the circuit and again note down the readings of all the meters. 5) Do the calculations as given in the calculation table and write down the result. 6) Draw the graph for at least three set of readings. 7) Calculate power factor of the circuit from the graph also.

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 46

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

OBSERVATIONS:

S.N

Applied Voltage V (V)

Current I (A)

Voltage across resistor VR (V)

Voltage across inductor VL (V)

Voltage across capacitor VC (V)

Total Power P (W)

1 2 3 4 5 6

SPACE FOR OBSERVATIONS (IF THERE IS CHANGE IN OBSERVATIONS GIVEN ABOVE):

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 47

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

CALCULATIONS:

S.N

R = VR/I

XL = VL/I

XC = VC/I

Z = √R² + (XL - XC)²

p.f, cosФ = R/Z

p.f from phasor diagram

1 2 3 4 5 6

S.N V = √VR² + (VL – VC)²

S =VI

p.f, cosФ = P/VI

R = P/I²

Z = V/I

1 2 3 4 5 6

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 48

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

GRAPHS: i)

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 49

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

ii)

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 50

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

iii)

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 51

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

iv)

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 52

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

RESULTS/CONCLUSION: _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ PRECAUTIONS: _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 53

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

EXPERIMENT NO. 8 AIM:

Study of Parallel R-L-C circuit.

SIGNIFICANCE: APPRATUS:

1) 2) 3) 4) 5)

Connecting wires, A.C Voltmeters (0-300V) – 1 no, A.C Ammeter (0-2A) – 3 no, Wattmeter (10A, 300V) – 1 no. A.C Ammeter (0-5A) – 1 no.

THEORY: Figure 1 shows the parallel RLC circuit. Writing KCL equation, we get total current I supplied by the applied voltage as I = IR + IL + IC = + V/jXL + V/-jXC = VG + V(-jYL) + (jYC) Or

I = V[G + j(Yc - YL)] = VY

Where, y is the complex admittance of the given circuit. Obviously, G = ; Y = 1/XL = 1/ωL and YC = 1/XC = ωC/1 = ωC Note that +j is associated with YC (and not with XL) and –j with YL. The complexadmittance of the circuit can be written as Y = G + j(Yc - YL) = √ G² + (Yc - YL)² ∠tan^-1

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 54

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

CIRCUIT DIAGRAM:

SPACE FOR CIRCUIT DIAGRAM (IF THERE IS CHANGE IN DIAGRAM GIVEN ABOVE):

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 55

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

PROCEDURE: 1) Connect the circuit as shown in figure. Connect resistor, inductor and capacitor in parallel. Keep the resistor, inductor and capacitor at one position. 2) Initially keep the autotransformer at zero position. Now gradually increase the voltage and bring it upto one level. 3) Note down the readings of applied voltage, total current and current through resistor, inductor and capacitor and also note down power. 4) Now change the value of resistance or inductance or capacitance or all in the circuit and again note down the readings of all the meters. 5) Do the calculations as given in the calculation table and write down the result. 6) Draw the graph for at least three set of readings. 7) Calculate power factor of the circuit from the graph also.

OBSERVATIONS:

S.N

Applied Voltage V (V)

Total Current I (A)

Current through resistor IR (V)

Current through inductor IL (V)

Current through capacitor IC (V)

Total Power P (W)

1 2 3 4 5 6

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 56

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

SPACE FOR OBSERVATIONS (IF THERE IS CHANGE IN OBSERVATIONS GIVEN ABOVE):

CALCULATIONS:

S.N

R= VR/IR

XL = VL/IL

XC = VC/IC

Y = √G² + (YC - YL)²

Y = I/V

p.f from phasor diagram

1 2 3 4 5 6

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 57

ELECTRICAL ENGINEERING PRACTICAL

S.N I = √IR² + (IL – IC)²

S =VI

GROUP B

p.f, cosФ = G/Y

R = P/I²

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

p.f, cosФ = P/VI

Page 58

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

GRAPHS: i)

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 59

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

ii)

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 60

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

iii)

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 61

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

RESULTS/CONCLUSION: _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ PRECAUTIONS: _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 62

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

EXPERIMENT NO. 9 Study of Resonance in R-L-C series circuit.

AIM: SIGNIFICANCE: APPRATUS:

1) 2) 3) 4) 5) 6)

Connecting wires, Function Generator – 1no. A. C Voltmeter (0 – 150V) – 1no. Digital Multimeters. A.C Ammeter (0 – 5A) – 1no. A. C Voltmeter (0 – 50V) – 3no.

THEORY: A RLC series network is said to be in resonance when the applied voltage and current are in phase and the frequency at which this phenomena occurs is known as resonance frequency fr. Resonance occurs when inductive reactance is equal to capacitive reactance i.e. XL = XC. Resonant frequency fr =

∏√

At resonance the impedance is pure resistance .At resonance frequency the current in the circuit is maximum which is given by Imax. BAND WIDTH: A band of frequencies at which the current is 1

√2

times its maximum value. At that

instant the power delivered to the circuit is half of the power at resonance. Hence they are called as half power frequencies f1 and f2. The frequency f1 is termed as lower cut off frequency and f2 is termed as upper cut off frequency. And hence the difference between the two half power frequencies is known as Band-width. B.W = f2 - f1 QUALITY FACTOR: The ratio between resonance frequency fr to bandwidth B.W. It is also given as the ratio of capacitor or inductor voltage at resonance to supply voltage. Q factor =

or

Q factor =

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 63

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

CIRCUIT DIAGRAM:

SPACE FOR CIRCUIT DIAGRAM (IF THERE IS CHANGE IN DIAGRAM GIVEN ABOVE):

PROCEDURE: 1) Connect the circuit as shown in figure. 2) Set the voltage of the signal from function generator to 5V.

3) Vary the frequency of the signal from 100 Hz to 1KHz in steps and note down the corresponding ammeter readings. 4) Observe that the current first increases & then decreases in case of series resonant circuit & the value of frequency corresponding to maximum current is equal to resonant frequency.

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 64

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

5) Note down this frequency and also value of current at resonant frequency. Also note down voltage across inductor, capacitor and resistor at every instant. 6) Draw a graph between frequency and current & calculate the values of bandwidth & quality factor.

OBSERVATIONS:

S. No.

Frequency (Hz)

Current (mA)

Voltage across resistor VR (V)

Voltage across inductor VL (V)

Voltage across capacitor VC (V)

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20.

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 65

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

SPACE FOR OBSERVATIONS (IF THERE IS CHANGE IN OBSERVATIONS GIVEN ABOVE):

CALCULATIONS: 1) Resonant frequency fr =

∏√

2) B.W = f2 - f1 3) Q factor =

or

4) Q factor =

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 66

ELECTRICAL ENGINEERING PRACTICAL

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

GROUP B

Page 67

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

GRAPHS:

i)

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 68

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

ii)

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 69

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

iii)

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 70

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

RESULTS/CONCLUSION: _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ PRECAUTIONS: _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 71

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

EXPERIMENT NO. 10 AIM:

Measurement of power and power factor in a single phase ac circuit.

SIGNIFICANCE:

APPRATUS:

i) Active power can be measured for any type of load. ii) Power factor and Reactive power can be calculated if we also measure voltage across and current flowing through the load.

1) 2) 3) 4) 5) 6) 7)

Connecting wires, Ammeter (0-5A) – 1nos. Voltmeter (0-300V) – 1nos. Wattmeter (10A, 300V) – 1 nos. Load bank. Decade resistance, capacitance, inductance box – 1 each. Autotransformer.

THEORY:

The active power or average power or real power in any single phase load can be measured with the help of dynamometer type wattmeter. The wattmeter contains two coils current coil and pressure or voltage coil. Current coil (CC) is connected in series with the load and pressure coil (PC) is connected in parallel with the load. Wattmeter has four terminals M, L, C, V. The terminal M is connected to mains supply, terminal L is connected on the load side, terminal V is connected to the other end of the load and terminals M and C are short circuited. If we also connect the ammeter and voltmeter along with the wattmeter, we can also measure the voltage across the load and current through it and the product of voltage and current will give apparent power (VI). After knowing active and apparent power we can easily calculate power factor of the load.

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 72

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

CIRCUIT DIAGRAM:

SPACE FOR CIRCUIT DIAGRAM (IF THERE IS CHANGE IN DIAGRAM GIVEN ABOVE):

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 73

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

PROCEDURE: 1) Connect the circuit as shown in the circuit diagram using connecting wires and the measuring 2) 3) 4) 5) 6) 7)

instruments. Keep the dimmerstat at minimum position and gradually increase the value of voltage at one level by looking at voltmeter. Initially keep the switch of load bank open, at this time current and power will be zero. Take the reading of all the three meters. Now close the switch of load bank, and increase the load gradually by closing one switch at a time. Every time when you increase the load, adjust the voltage to its initial value using autotransformer, if it gets changed. Note down the reading of all the meters, every time when you increase the load by closing one or two switch at a time. Calculate power and power factor using above given formula.

OBSERVATIONS:

S.N

Voltage (V)

Current (A)

Active Power,P (W)

Apparent Power S = VI

Power Factor, cosФ

1 2 3 4 5 6

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 74

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

SPACE FOR OBSERVATIONS (IF THERE IS CHANGE IN OBSERVATIONS GIVEN ABOVE):

CALCULATIONS:

Active Power, P = VIcosФ, Apparent Power, S = VI, Power Factor, cosФ = (Active Power/Apparent Power) = P/S.

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 75

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

RESULTS/CONCLUSION: _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ PRECAUTIONS: _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 76

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

EXPERIMENT NO. 11 AIM:

To study starting of dc shunt motor using three point starter and reversing of dc shunt motor.

SIGNIFICANCE:

APPRATUS:

i) Need of starter at the time of starting. ii) Reversing of DC shunt motor.

1) 2) 3) 4)

Connecting wires, DC shunt motor, Three point starter, Variable DC power supply (30A)

THEORY: DC shunt motor is widely used motor in industrial applications. It is a constant speed motor idealy but there some drop in speed from no-load to full-load practically. The dc shunt motor is started with the help of three point starter. Starter consists of resistances in series with armature which limits the starting current of motor and the resistance is gradually cut-out as the motor gains speed. Once the motor is attaining full speed all resistances of starter has been cut out and motor run at rated speed. Since the back emf of motor is zero at the time of staring as motor is at rest so the heavy current can flow through armature and to limit this starter is used. The direction of dc shunt motor can be reversed or changed either by interchanging its field terminals or armature terminals but not both, because changing both the field and armature terminals will not change the direction of motor and the motor will continue to run in same direction.

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 77

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

CIRCUIT DIAGRAM:

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 78

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

SPACE FOR CIRCUIT DIAGRAM (IF THERE IS CHANGE IN DIAGRAM GIVEN ABOVE):

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 79

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

PROCEDURE: 1) Connect the circuit as shown in figure 1. Positive of supply is connected to field point F of motor through starter and negative connected to point FF of field. 2) Now switch on the dc supply source and move the starter arm gradually. The motor will pick up the speed slowly and finally runs at rated speed. 3) Note the direction of motor. 4) Now switch off the supply and interchange the field winding terminals F-FF as shown in figure 2, negative of supply connected to F of field and positive now connected to FF of field through starter. 5) Again move the starter arm gradually. The motor will pick up the speed slowly and finally runs at rated speed. 6) And again note down the direction of motor. 7) Now switch off the supply and interchange the armature winding terminals A-AA as shown in figure 3, negative of supply connected to A of armature and positive now connected to AA of armature through starter. 8) Again move the starter arm gradually. The motor will pick up the speed slowly and finally runs at rated speed. 9) And again note down the direction of motor. 10) Disconnect the circuit after finishing experiment.

OBSERVATIONS: _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________

SPACE FOR OBSERVATIONS (IF THERE IS CHANGE IN OBSERVATIONS GIVEN ABOVE): _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 80

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

RESULTS/CONCLUSION: _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ PRECAUTIONS: _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 81

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

EXPERIMENT NO. 12 AIM:

Determination of voltage and current ratio of single phase transformer.

SIGNIFICANCE: APPRATUS:

1) 2) 3) 4) 5)

Connecting wires, A.C Ammeter (0-5A) – 2nos. Voltmeter (0-300V) – 2nos. Load bank. Autotransformer.

CIRCUIT DIAGRAM:

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 82

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

SPACE FOR CIRCUIT DIAGRAM (IF THERE IS CHANGE IN DIAGRAM GIVEN ABOVE):

PROCEDURE: 1) Connect the circuit as shown in the circuit diagram using connecting wires and the measuring instruments. 2) Gradually increase the voltage applied to primary using autotransformer and set it to one level by looking at voltmeter. 3) Initially keep the switch of load bank open, at this time current will be zero. Take the reading of all the three meters. 4) Now close the switch of load bank, and increase the load gradually by closing one switch at a time. 5) Every time when you increase the load, ajdust the primary side voltage to its initial value using autotransformer. 6) Note down the reading of all the meters, every time when you increase the load. 7) Calculate the voltage and current ratios.

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 83

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

OBSERVATIONS:

SR NO.

PRIMARY SIDE Voltage V1 (V)

Current I1 (A)

SECONDARY SIDE Voltage V2 (V)

Voltage Ratio, V1/V2

Current Ratio, I2/I1

Current I2 (A)

1 2 3 4 5 SPACE FOR OBSERVATIONS (IF THERE IS CHANGE IN OBSERVATIONS GIVEN ABOVE):

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 84

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

CALCULATIONS:

VOLTAGE RATIO = V1/V2, CURRENT RATIO = I1/I2, RELATIONSHIP:

=

RESULTS/CONCLUSION: _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ PRECAUTIONS: _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 85

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

EXPERIMENT NO. 13 AIM:

Determination of Efficiency and Regulation of single phase Transformer by direct loading.

SIGNIFICANCE: From this test we can find out at which load transformer has maximum efficiency and by how much amount secondary side voltage changes on loading a transformer. APPRATUS:

1) 2) 3) 4) 5) 6) 7)

Connecting wires, A.C Ammeter (0-5A) – 1nos. A. C Ammeter (0-10A) – 1nos. A.C Voltmeter (0-300V) – 2nos. Load bank. Autotransformer. Wattmeter (10A, 300V) – 2nos.

THEORY:

In a practical transformer there are two types of losses: (1) Cu loss (2) Core/Iron loss. Therefore output of a transformer is always less than input of the transformer. Here transformer is loaded with a variable resistive load. Input to the transformer can be found out by using a wattmeter and output can also be measured by a wattmeter or with the help of voltmeter and ammeter. Input power to transformer = Reading of wattmeter W1 Output power from transformer = Reading of wattmeter W2 % efficiency η = (Output Power / Input Power) × 100% = (W2 / W1) × 100%

Voltage regulation(V.R) is the change in the magnitude of secondary voltage from no load to desired load. This change is expressed as a percentage of the full load voltage. % V.R =

( (

)

)

X 100 %

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 86

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

CIRCUIT DIAGRAM:

SPACE FOR CIRCUIT DIAGRAM (IF THERE IS CHANGE IN DIAGRAM GIVEN ABOVE):

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 87

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

PROCEDURE: 1) Connect the circuit as shown in figure. 2) Initially keep the dimmerstat or autotransformer at zero position. And also keep the switch of the load bank open. Now, gradually increase the voltage and bring it upto rated voltage. Note down this reading of voltage on both the side of transformer. This reading of voltage on secondary side is open circuit secondary voltage. 3) Now close the switch of the load bank and gradually increase the load. Every time when load is increased, note down the readings of voltage, current and power on both the sides of the transformer in observation table. 4) Calculate percent voltage regulation and percent efficiency by formula as given in calaculations.

OBSERVATIONS: Open circuit secondary voltage V20 = ___________

Primary Side

S.N

Voltage V1 (V)

Current I1 (A)

Secondary Side Power P1 (wattmeter reading x multiplying factor) (W)

Voltage V2 (V)

Current I2 (A)

Power P2 (wattmeter reading x multiplying factor) (W)

1 2 3 4 5 6

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 88

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

SPACE FOR OBSERVATIONS (IF THERE IS CHANGE IN OBSERVATIONS GIVEN ABOVE):

CALCULATIONS:

S.N

% Voltage Regulation =

X 100

% Efficiency =

X 100

1 2 3 4 5 6

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 89

ELECTRICAL ENGINEERING PRACTICAL

GRAPHS:

GROUP B

i) Plot graph between output power P2 on X-axis and % Voltage Regulation on Y-axis.

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 90

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

ii) Plot graph between output power P2 on X-axis and % efficiency on Y-axis.

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 91

ELECTRICAL ENGINEERING PRACTICAL

GROUP B

RESULTS/CONCLUSION: _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ PRECAUTIONS: _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________

PROF. RAM MEGHE COLLEGE OF ENGINEERING AND MANAGEMENGT

Page 92