POWER SYSTEM - II LAB
POWER SYSTEM -II
LAB MANUAL
(EE-328)
VI SEMESTER
ELECTRICAL ENGINEERING
RAO PAHLAD SINGH GROUP OF INSTITUTIONS
BALANA (MOHINDER GARH) 123029
(DEPARTMENT OF ELECTRICAL ENGINEERING)
Submitted by:
Karambir Sheoran
Asstt.Professor ,EE Deptt.
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POWER SYSTEM - II LAB
LIST OF EXPERIMENTS
Sr. No. TITLE Page No.
1. To study the performance of under voltage relay. 3
2. To study performance characteristics of typical DC 4
distribution system in radial Configuration.
3. To study performance characteristics of typical DC 6
distribution system in ring main configuration.
4. Testing of breakdown strength of a transformer oil. 8
5. To study characteristics of MCB & HRC Fuse. 10
6. To study the performance of an over voltage relay. 12
7. Determine the ABCD,H, Z and Image parameters of Short 13
Transmission Line
8. Determine the ABCD,H,Z and Image parameters of Medium 16
Transmission Line
9. Determine the ABCD,H,Z and Image parameters of Long 19
Transmission Line
10. To study flash point test of transformer oil. 22
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POWER SYSTEM - II LAB
EXPERIMENT NO. - 1
AIM: - To study the performance of under voltage relay.
Circuit Diagram:-
Theory:
The operating torque is provided by the spring and restraining torque is proportional to the
Voltage. K1 – K2V2 > 0
Procedure:
Chose the required relay setting (% of 110V) and TSM
By the Autotransformer set the circuit to a particular PSM with DPDT at 1
Put the DPDT to 2 to reset the Relay (disc should return to its original position)
Switch over to 1 (DPDT), record the time of operation of the Relay, till the contactor
trips.
Repeat 1-4 for at least two TSMs and two relay settings.
Precaution:
Slowly increase the Voltage to the required value.
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POWER SYSTEM - II LAB
EXPERIMENT NO. -2
AIM: - To study performance characteristics of typical DC distribution system in
radial.
Requirements:-
Main Cord
Patch Cords
40W bulbs (5)
Theory:
Whole of the power system can be subdivided in to number of radial feeders fed from one
End. Generally such radial feeders are protected by over current and earth fault relays
Used as primary relays for 11 kV and 66 kV lines. For lines of voltage rating beyond 66
KV, distance protection is applied as a primary protection whereas over current and earth
Fault relays are used as back up relays.
A simplified radial feeder network without transformers (in actual practice transformers
Do exist at substations) is shown in single line diagram of fig. 1.1 below.
If the fault occurs in distribution network, fuse should isolate the faulty section. Should
The fuse fail, relay R3 shall give back-up protection. Relays R1, R2, and R3 act as primary
Relays for faults in section I, section I, and section III respectively. If fault in section III is
Not cleared by relaying scheme at relaying point R3, relay R2 will act as a back-up.
Similarly back-up protection is provided by relay R1 for faults in section II. A, B, C and D
Are substations in fig. 1.1 .
Procedure:
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POWER SYSTEM - II LAB
1. Frist of all make sure that the earthing of your laboratory is proper and connected to
theTerminal provided on back side of the panel.
2. Make sure that the variac knob is at zero position.
3. Make the connection according to Diagram.
4. Now insert 40W bulbs into bulb holders.
5. Now switch ON the AC mains and MCB of your trainer.
6. Now vary the knob of variac up to 220V.
7. Switch ON all the toggle switches S1, S2, S3, S4 and S5. (Upward direction).
8. You will observe all the bulbs in Radial Distribution section will glow. That means all
theConnections are right.
9. Now put the variac knob at zero position.
10. Connect voltmeter terminal V4 to – ve terminal of Consumer4.
11. Now insert one end of patch cord to V3 terminal & second end will connect to
measuredterminals.
12. Once again vary the knob of variac up to 220V.
13. Now observe the voltage drop in each Consumer terminal and note the readings.
14. Put the variac knob at zero position.
15. Switch Off the mains and remove all the connection and bulbs.
Results:
If the distributor is connected to the supply system on one end only then the end of the
feederNearest to the generating station would be heavily loaded and the Consumers at
the distance end of the distributor would be subjected to large voltage variations as the
load varies.
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POWER SYSTEM - II LAB
EXPERIMENT NO. -3
AIM: - To study performance characteristics of typical DC distribution system in ring.
Requirements:-
Main Cord
Patch Cords
40W bulbs (5)
Theory:
One ring network of distributors is fed by more than one feeder. In this case if one feeder is
Under fault or maintenance, the ring distributor is still energized by other feeders connected
to it. In this way the supply to the consumers is not affected even when any feeder becomes
out of service. In addition to that the ring main system is also provided with different section
Isolates at different suitable points. If any fault occurs on any section, of the ring, this section
Can easily be isolated by opening the associated section isolators on both sides of the faulty
Zone.
Procedure:
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POWER SYSTEM - II LAB
Frist of all make sure that the earthing of your laboratory is proper and connected to
theTerminal provided on back side of the panel.
Make sure that the variac knob is at zero position.
Make the connection according to Diagram.
Now insert 40W bulbs into bulb holders.
Now switch ON the AC mains and MCB of your trainer.
Now vary the knob of variac up to 220V.
Switch ON all the toggle switches S1, S2, S3, S4 and S5. (Upward direction).
You will observe all the bulbs in Radial Distribution section will glow. That means all
theConnections are right.
Now put the variac knob at zero position.
Connect voltmeter terminal V6 to –ve terminal of source1.
Now insert one end of patch cord to V5 terminal & second end will connect to
measure Terminals.
Once again vary the knob of variac up to 220V.
Now observe the voltage drop in each Consumer terminal and note the readings.
Put the variac knob at zero postion.
Switch Off the mains and remove all the connection and bulbs.
Result:
If the distributor is connected to the supply system at both ends then the load is
equally distributed at both ends and no voltage variations as the load varies.
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POWER SYSTEM - II LAB
EXPERIMENT NO. - 4
AIM: -Testing of breakdown strength of transformer oil.
Requirements:-
1. Transformer oil test kit
2. Transformer oil.
Theory:-
The insulation oil of voltage- and current-transformers fulfills the purpose of insulating as
well as Cooling. Thus, the dielectric quality of transformer oil is a matter of secure operation
of a transformer. As transformer oil deteriorates through aging and moisture ingress,
transformer oil should, depending on economics, transformer duty and other factors, be tested
periodically.
Procedure:-
Make sure that the mains switch of control panel is off position.
Now take out the acrylic oil cup from the setup.
Adjust the gap in between both electrodes in the oil cup with the help of “GO” and
“NOGO” gauge provided
Fill the transformer oil in the acrylic oil cup up to top level and keep the oil cup on
the aluminum studs carefully placed on output insulators.
Let the oil settle for half minute.
Cover the oil cup & closed acrylic top door of the control panel properly.
Connect the main cord to the mains socket (230V).
Switch ON mains supply as well as mains switch provide in front panel of control
setup.
After switch on the panel, green neon lamp will glow.it indicate that input supply
appears at the control setup but high voltage is off.
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POWER SYSTEM - II LAB
If green lamp does not glow, then check whether acrylic door is properly closed or
not.
Now turn the toggle switch at „Raise‟ position.
After that turn on the HV On switch on the panel then Red neon lamp will glow. It
indicate that high voltage is being generated at the secondary winding of the
transformer that is high Voltage is present between the electrodes in the oil cup.
At some point of voltage, the insulation of the test oil get breakdown and a spark is
seen in between the electrodes instantaneously.
Record the reading of voltmeter into observation table.
Repeat the above steps and take no. of readings in fixed time interval.
Switch off the main supply.
Results:-
We have successfully tested breakdown strength of a transformer oil.
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POWER SYSTEM - II LAB
EXPERIMENT NO. - 5
AIM: - To study characteristics of MCB & HRC Fuse.
Requirements:-
Rheostat 220 ohm.2.8 A
Connecting leads
Procedure:-
Make sure that the switch S1 is off means the circuit is open.
Make the connection according to the diagram.
Put the B type MCB knob upwards.
Switch On the mains, LCD switch S2 and S1 switch.
With the help of variac and rheostat adjust the current say 9A.
After adjusting the current switch off S1.
Now again on the switch S1 and measure the current reading.
Now switch off the switch S1 &then switch S2.
Repeat the process and take 5-6 readings on the current rating.
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POWER SYSTEM - II LAB
Switch off the mains supply.
Results:-
We have successfully studied about the MCB and HRC fuse.
EXPERIMENT NO. –6
AIM: -To study the performance of over voltage relay.
Circuit Diagram:-
Theory:
The operating torque is provided by the spring and restraining torque is proportional to
The voltage. K1 – K2V2 > 0
Procedure:
Chose the required relay setting (% of 110V) and TSM
By the Autotransformer set the circuit to a particular PSM with DPDT at 1
Put the DPDT to 2 to reset the Relay (disc should return to its original position)
Switch over to 1 (DPDT), record the time of operation of the Relay, till the contactor
trips.
Repeat 1-4 for at least two TSMs and two relay settings.
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POWER SYSTEM - II LAB
Precaution:
Slowly increase the Voltage to the required value.
Results:
We have successfully studied the working of over voltage relay.
EXPERIMENT NO. - 7
AIM: - Determine the ABCD, H, Z and Image parameters of Short Transmission Line.
Requirements:-
1. Connecting Leads.
Theory:
The transmission lines which have length less than 80 km are generally referred as short
Transmission lines. For short length, the shunt capacitance of this type of line is neglected
and other parameters like electrical resistance and inductor of these short lines are lumped.
1. Open Circuit the Output Terminal
Procedure:
The AC supply is off and variac knob is at zero position
Make the connection according to the diagram.
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POWER SYSTEM - II LAB
Measure the sending end receiving end current and voltage respectively with the help
ofswitch S1,S2,S3
S1 Switch: Simultaneously get sending end and receiving end voltage,
current, active,Reactive, apparent power and power factor.
S2 Switch: get sending end and receiving end active, reactive, apparent
power.
S3 Switch: get sending end and receiving end voltage, current, and power
factor.
Select the switch as you want.
After completion of the entire connection, connect the main cord to the panel &
switch onthe power supply.
With the help of variac adjust the voltage up to 110 volt.
Now by using the values of Vs, Is &Vr we can easily calculate the
dimensionlesscoefficient A and admittance C.
Switch off the power system
Dimensionless Coefficient (A) = Vs/Vr
Admittance C = Is/Vr
2. Short Circuit the Output Terminal
Procedure:
Short line connection remains same, you have to just short output terminal.
Measure the sending end receiving end current and voltage respectively with the help
of Switch S1, S2, and S3.
S1 Switch: Simultaneously get sending end and receiving end voltage,
current, active, reactive, apparent power and power factor.
S2 Switch: get sending end and receiving end active, reactive, apparent
power.
S3 Switch: get sending end and receiving end voltage, current, and power
factor.
Select the switch as you want.
After completion of the entire connection, connect the main cord to the panel &
switch on thepower supply.
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POWER SYSTEM - II LAB
With the help of variac adjust the voltage up to 110 volt.
In short test you will get Vs, Is, Ir values and the values of Vr is zero because output
terminal isshort circuited.
By using their values easily find short transmission line Impedance B and
DimensionlessCoefficient D.
Switch off the power supply.
Impedance (B) = Vs/Ir
Dimensionless Coefficient (D) = Is/Ir
Image Parameter of short line
1. When short line‟s output terminal was short circuited the ratio of sending end
voltage and current is called Zsc.
Zsc = Vs/Is
2. When short line‟s output terminal was open circuited the ratio of sending end
voltage and Current is called Zoc.
Zoc = Vs/Is
3. Characteristic Impedance (Zo) = Zsc * Zoc
H parameter
H11 = B/D
H12 = (AD-BC) / D
H21 = -1/D
H22 = C/D
Z Parameter
Z11 = B/C
Z12 = (AD – BC)/C
Z21 = 1/C
Z22 = D/C
Results:-
We have successfully studied about the H, Z, and ABCD parameters of short
transmission line.
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POWER SYSTEM - II LAB
EXPERIMENT NO. - 8
AIM: - Determine the ABCD, H, Z and Image parameters of Medium Transmission
Line.
Requirements:
1. Connecting Leads
Theory:
The transmission line having its effective length more than 80 km but less than 250 km, is
Generally referred to as a medium transmission line. Due to the line length being
considerably high, admittance Y of the network does play a role in calculating the effective
circuit parameters, unlike in the case of short transmission lines. For this reason the
modelling of a medium lengthtransmission line is done using lumped shunt admittance
along with the lumped impedance in series to the circuit.
1. Open Circuit the Output Terminal
Procedure:
The AC supply is off and variac knob is at zero position
Make the connection according to the diagram.
Measure the sending end receiving end current and voltage respectively with the help
of switch S1, S2, S3.
S1 Switch: Simultaneously get sending end and receiving end voltage,
current, active, reactive, apparent power and power factor.
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POWER SYSTEM - II LAB
S2 Switch: get sending end and receiving end active, reactive, apparent
power.
S3 Switch: get sending end and receiving end voltage, current, and power
factor.
Select the switch as you want.
After completion of the entire connection, connect the main cord to the panel &
switch on the power supply.
With the help of variac adjust the voltage up to 220 volt.
Now by using the values of Vs, Is &Vr we can easily calculate the dimensionless
coefficient A and admittance C.
Switch off the power system.
Dimensionless Coefficient (A) = Vs/Vr
Admittance C = Is/Vr
2.Short Circuit the Output Terminal
Procedure:
Short line connection remains same, you have to just short output terminal.
Measure the sending end receiving end current and voltage respectively with the help
ofswitch S1, S2, S3.
S1 Switch: Simultaneously get sending end and receiving end voltage,
current, active,reactive, apparent power and power factor.
S2 Switch: get sending end and receiving end active, reactive, apparent
power.
S3 Switch: get sending end and receiving end voltage, current, and power
factor.
Select the switch as you want.
After completion of the entire connection, connect the main cord to the panel &
switch on thepower supply.
With the help of variac adjust the voltage up to 220 volt.
In short test you will get Vs, Is, Ir values and the values of Vr is zero because output
terminal isshort circuited.
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POWER SYSTEM - II LAB
By using their values easily find short transmission line Impedance B and
DimensionlessCoefficient D.
Switch off the power supply.
Impedance (B) = Vs/Ir
Dimensionless Coefficient (D) = Is/Ir
Image Parameter of short line
When short line‟s output terminal was short circuited the ratio of sending end voltage
and current is called Zsc.
Zsc = Vs/Is
When short line‟s output terminal was open circuited the ratio of sending end voltage
and current is called Zoc.
Zoc = Vs/Is
Characteristic Impedance (Zo) = Zsc * Zoc
H parameter
H11 = B/D
H12 = (AD-BC) / D
H21 = -1/D
H22 = C/D.
Z Parameter
Z11 = B/C
Z12 = (AD – BC)/C
Z21 = 1/C
Z22 = D/C
Results:
We have successfully studied about the H, Z, and ABCD parameters of medium
transmission line.
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POWER SYSTEM - II LAB
EXPERIMENT NO. - 9
AIM:-Determine the ABCD, H, Z and Image parameters of Long Transmission Line.
Requirements:
Connecting Leads
Theory:
A power transmission line with its effective length of around 250 Kms or above is referred to
as a long transmission line. Calculations related to circuit parameters (ABCD parameters) of
sucha power transmission is not that simple, as was the case for a short transmission line or
mediumtransmission line. The reason being that, the effective circuit length in this case is
much higher than what it was for the former models.
1. Open Circuit the Output Terminal
Procedure:
The AC supply is off and variac knob is at zero position
Make the connection according to the diagram.
Measure the sending end receiving end current and voltage respectively with the help
of switch S1, S2, S3.
S1 Switch: Simultaneously get sending end and receiving end voltage,
current, active, Reactive, apparent power and power factor.
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POWER SYSTEM - II LAB
S2 Switch: get sending end and receiving end active, reactive, apparent
power.
S3 Switch: get sending end and receiving end voltage, current, and power
factor.
Select the switch as you want.
After completion of the entire connection, connect the main cord to the panel &
switch on the power supply.
With the help of variac adjust the voltage up to 220 volt.
Now by using the values of Vs, Is &Vr we can easily calculate the dimensionless
coefficient A and admittance C.
Switch off the power system.
Dimensionless Coefficient (A) = Vs/Vr
Admittance C = Is/Vr
2. Short Circuit the Output Terminal
Procedure:
Short line connection remains same, you have to just short output terminal.
Measure the sending end receiving end current and voltage respectively with the help
ofswitch S1, S2, S3.
S1 Switch: Simultaneously get sending end and receiving end voltage,
current, active, Reactive, apparent power and power factor.
S2 Switch: get sending end and receiving end active, reactive, apparent
power.
S3 Switch: get sending end and receiving end voltage, current, and power
factor.
Select the switch as you want.
After completion of the entire connection, connect the main cord to the panel &
switch on thepower supply.
With the help of variac adjust the voltage up to 220 volt.
In short test you will get Vs, Is, Ir values and the values of Vr is zero because output
terminal isshort circuited.
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POWER SYSTEM - II LAB
By using their values easily find short transmission line Impedance B and
DimensionlessCoefficient D.
Switch off the power supply.
Impedance (B) = Vs/Ir
Dimensionless Coefficient (D) = Is/Ir
Image Parameter of short line
When short line‟s output terminal was short circuited the ratio of sending end voltage
andCurrent is called Zsc.
Zsc = Vs/Is
When short line‟s output terminal was open circuited the ratio of sending end voltage
and Current is called Zoc.
Zoc = Vs/Is
Characteristic Impedance (Zo) = Zsc * Zoc
H parameter
H11 = B/D
H12 = (AD-BC) / D
H21 = -1/D
H22 = C/D
Z Parameter
Z11 = B/C
Z12 = (AD – BC)/C
Z21 = 1/C
Z22 = D/C
Results:
We have successfully studied about the H, Z, and ABCD parameters of long
transmission line.
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POWER SYSTEM - II LAB
EXPERIMENT NO. - 10
AIM: - Study of Flash & Fire Point test of Transformer oil.
Requirements:
1. Transformer Oil
2. Electric Lighter
Theory:
Transformer oil or insulating oil is a highly refined mineral oil that is stable at high
Temperatures and has excellent electrical insulating properties. It is used in oil filled
Transformers, some types of high voltage capacitors, fluorescent lamp ballasts, and some
Types of high voltage switches and circuit breakers. Its functions are to insulate,
Suppress corona and arcing, and to serve as a coolant.
Procedure:
Ensure that mains switch at the control set-up is at off position
Clean oil cup carefully to avoid any contamination and fill half a cup from
transformer oil
Keep the oil cup into its respective position
Adjust the thermostat rod in such a way that it must be half filled into oil cup and
tighten it by providing screw on its stand.
Cover up oil cup.
Switch on mains as well as the MCB
Observe the temperature start increasing from its normal temperature.
Now observe the oil until it evaporates and vapors comes out from the oil cup.
Now use electric lighter to ignite the oil by uncover half of the oil cup.
Times when oil catch fire for a large time indicates fire point of the oil.
Cover up the oil cup to extinguish fire into oil cup.
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POWER SYSTEM - II LAB
Push heating on/off switch to stop heating indicated by red LED blow out.
Switch off mains as well as the MCB.
Results:
Flash Point of the Transformer oil: -1400C
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