7/27/2019 EC2259 LAB Manual
1/82
EC2259 Electrical Engineering And Control System Lab Manual
EC 2259 ELECTRICAL ENGINEERING AND CONTROL SYSTEM LAB 0 0 3 2
AIM
To expose the students to the basic operations of electrical machines and help them todevelop experimental skills.
1. To study the concepts, performance characteristics, time and frequency response oflinear systems.
2. To study the effects of controllers.
1. Open circuit and load characteristics of separately excited and self excited D.C.generator.
2. Load test on D.C. shunt motor.
3. Swinburnes test and speed control of D.C. shunt motor.
4. Load test on single phase transformer and open circuit and short circuit test on singlephase transformer
5. Regulation of three phase alternator by EMF and MMF methods.6. Load test on three phase induction motor.
7. No load and blocked rotor tests on three phase induction motor (Determination ofequivalent circuit parameters)
8. Study of D.C. motor and induction motor starters.
9. Digital simulation of linear systems.
10.Stability Analysis of Linear system using Mat lab.
11.Study the effect of P, PI, PID controllers using Mat lab.
12.Design of Lead and Lag compensator.
13.Transfer Function of separately excited D.C.Generator.14.Transfer Function of armature and Field Controller D.C.Motor.
P = 45 Total = 45
1. Open circuit and load characteristics of separately excited and self excited D.C.
generator.
Sl. No. Apparatus Range Quantity1 Motor Generator set - 12 Rheostat 200, 5A
175, 1.5A
1
23 Voltmeter DC 300V
30V11
4 Ammeter DC 30A2A
12
5 DPST switch 26 Three point starter 17 Tachometer 1
7/27/2019 EC2259 LAB Manual
2/82
EC2259 Electrical Engineering And Control System Lab Manual
2. Load test on D.C. shunt motor.
Sl. No. Apparatus Range Quantity
1 DC Motor - 1
2 Rheostat 175, 1.5A 13 Voltmeter DC 300V 1
4 Ammeter DC 30A 1
5 DPST switch 1
6 Three point starter 1
7 Tachometer 1
3. Swinburnes test and speed control of D.C. shunt motor
Sl. No. Apparatus Range Quantity1 DC Motor - 1
2 Rheostat 100, 5A & 175, 1.5A 11
3 Voltmeter DC 300V 1
4 Ammeter DC 5A2A
11
5 DPST switch 1
6 Tachometer 1
4. Load test on single-phase transformer and open circuit and short circuit test on
single-phase transformer.
Sl. No. Apparatus Range Quantity1 Single phase Transformer - 12 Wattmeter 300V, 5A,UPF & 300V,
5A,LPF
1
13 Voltmeter AC 300V 24 Ammeter AC 5A
30A11
5 Single phase auto-transformer 16 Resistive load 1
5. Regulation of three-phase alternator by EMF and MMF method.
Sl. No. Apparatus Range Quantity
1 Motor Alternator set - 1
2 Rheostat 200, 5A &175, 1.5A 11
3 Voltmeter DCVoltmeter AC
300V600V
11
4 Ammeter DCAmmeter AC
2A30A
11
5 DPST switchTPST switch
11
6 Tachometer 1
7/27/2019 EC2259 LAB Manual
3/82
EC2259 Electrical Engineering And Control System Lab Manual
6. Load test on three phase Induction motor.
Sl. No. Apparatus Range Quantity1 Three Phase Induction Motor - 12 Wattmeter 600V, 10A,UPF 23 Voltmeter AC 600V 1
4 Ammeter AC 10A 15 Brake drum arrangement6 Star delta starter 17 Tachometer 1
7. No load and blocked rotor test on three-phase induction motor (Determination of
equivalent circuit parameters)
Sl. No. Apparatus Range Quantity1 Three Phase Induction Motor - 12 Wattmeter 600V, 10A,UPF
600V, 5A,LPF22
3 Voltmeter AC 600V150V
11
4 Ammeter AC 10A5A
11
5 Brake drum arrangement6 Three phase auto-transformer 1
8. Study of D.C. motor and Induction motor starters.
Sl. No. Apparatus Quantity1 Three point starter 12 Four point starter 1
3 Star-delta starter 14 DOL starter 15 Three phase auto-transformer 1
9. Digital simulation of linear systems.
Simulink software for minimum 3 users license
10. Stability analysis of linear system using Mat lab.
Matlab software for minimum 3 users license
11. Study of effect of P, PI, PID controllers using Mat lab.
Matlab software for minimum 3 users license
7/27/2019 EC2259 LAB Manual
4/82
EC2259 Electrical Engineering And Control System Lab Manual
12. Design of lead and lag compensator.
Sl. No. Apparatus
1 Resistor
2 Capacitor
3 Function generator
4 Bread Board
13. Transfer function of separately excited D.C. generator.
Sl. No. Apparatus Range Quantity1 Motor Generator set - 12 Rheostat 200, 5A
175, 1.5A12
3 Voltmeter DC 300V30V
11
4 Ammeter DC 30A
2A
1
25 DPST switch 26 Three point starter 17 Tachometer 1
14. Transfer function of armature and field controller D.C. motor.
Sl. No. Apparatus Range Quantity1 DC Motor - 12 Rheostat 175, 1.5A 1
3 Voltmeter DC 300V 14 Ammeter DC 30A 15 DPST switch 16 Three point starter 17 Tachometer 1
7/27/2019 EC2259 LAB Manual
5/82
EC2259 Electrical Engineering And Control System Lab Manual
!
" #
$ %
" #
& ' ( )
*
' ( )
+
, '- )
.
,/ ,' - )
0
() 1' 2 % 3 4 3 )
% 2% %)
' ) %)
% (5 (-5 (-
'
! ' ' )
$ 3 % "#
& 3 ) 3
7/27/2019 EC2259 LAB Manual
6/82
EC2259 Electrical Engineering And Control System Lab Manual
LOAD TEST ON DC SHUNT MOTOR
AIM
To conduct the load test on a given dc shunt motor and draw its performance curves.
NAME PLATE DETAILS
FUSE RATING
125% of rated current (full load current)
APPRATUS REQUIRED
S. NONAME OF THE
APPARATUSTYPE RANGE QUANTITY
1
2
3
4
Ammeter
Voltmeter
Rheostat
Tachometer
MC
MC
Wire wound
Digital
(0-20A)
(0-300V)
250, 2A
1
1
1
1
FORMULAE
1. Torque T = (S1~S2) (R+t/2) 9.81 in N-m.
Where R- Radius of the Break drum in m.
t- Thickness of the Belt in m.
S1,S2- Spring balance reading in Kg.
2. Input power = VL IL in Watts.
Where VL Load Voltage in Volts.
IL- Load current in Amps.
3. Output power = 2NT/60 in Watts.
Where N- Speed of the armature in rpm.
T- Torque in N-m.
4. Percentage of Efficiency = (Output power/Input power) 100
7/27/2019 EC2259 LAB Manual
7/82
EC2259 Electrical Engineering And Control System Lab Manual
CIRCUIT DIAGRAM FOR LOAD TEST ON DC SHUNT MOTOR
Model Graph
(A) Electrical characteristics (B) Mechanical characteristics
(C) Torque, Speed Vs Load Current
Fuse
BRAKE DRUM
S1 S2
220VDC SUPPLY
L F A
3 POINT STARTER
D
P
S
T
S
250, 2AF
FF
M
A
AA
V(0-300V)
MC
A
(0-20A)MC
Output power in watts
N
N in rpm
ILin Amps
T in N-m
%T
IL %
Speedinrpm
Torque in N-m
Torque Vs Speed
Speedin
rpm
Load Current in Amps
Speed
TorqueinN-m
Torque
7/27/2019 EC2259 LAB Manual
8/82
EC2259 Electrical Engineering And Control System Lab Manual
PRECAUTION
The motor field rheostat should be kept at minimum resistance position. At the time of starting, the motor should be in no load condition. The motor should be run in anticlockwise direction.
PROCEDURE
Connections are given as per the circuit diagram. Using the three-point starter the motor is started to run at the rated speed by adjusting the
field rheostat if necessary.
The meter readings are noted at no load condition. By using the Break drum with spring balance arrangement the motor is loaded and the
corresponding readings are noted up to the rated current.
After the observation of all the readings the load is released gradually. The motor is switched off by using the DPIC switch.
GRAPH
The graphs are drawn as
Output power Vs Efficiency Output power Vs Armature current Output power Vs Torque Output power Vs Speed Torque Vs Speed
Torque Vs Armature current Speed Vs Armature current
7/27/2019 EC2259 LAB Manual
9/82
EC2259 Electrical Engineering
Tabulation for load test on DC shunt motor
Radius of the brake dram = Thickness of the belt =
Spring balance readingLoadCurrent
(IL)
LoadVoltage
(VL)
Speed ofthe motor
(N)
S1S2
S1~S2
Torque (T)(S1~S2)(R+t/2)(9.81)
Outputpower
2NT/60S.No
Amps Volts Rpm Kg Kg Kg N-m Watts
7/27/2019 EC2259 LAB Manual
10/82
EC2259 Electrical Engineering And Control System Lab Manual
MODEL CALCULATION
RESULT
Thus the load test on DC shunt motor and its performance curves are drawn.
7/27/2019 EC2259 LAB Manual
11/82
EC2259 Electrical Engineering And Control System Lab Manual
SPEED CONTROL OF DC SHUNT MOTOR
AIM
To conduct an experiment to control the speed of the given dc shunt motor by field andarmature control method also to draw its characteristic curves.
NAME PLATE DETAILS
FUSE RATING
10% of rated current (full load current)
APPRATUS REQUIRED
S.NONAME OF THE
APPARATUSTYPE RANGE QUANTITY
1
2
3
4
5
6
Ammeter
Ammeter
Voltmeter
Rheostat
Rheostat
Tachometer
MC
MC
MC
Wire wound
Wire wound
Digital
(0-2A)
(0-10A)
(0-300V)
250, 2A
50, 5A
1
1
1
1
1
1
PRECAUTION
The motor field rheostat should be kept at minimum resistance position. The motor armature rheostat should be kept at maximum resistance position. The motor should be in no load condition throughout the experiment. The motor should be run in anticlockwise direction.
7/27/2019 EC2259 LAB Manual
12/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
CIRCUIT DIAGRAM FOR SPEED CONTROL OF DC SHUNT MOTOR
Tabulation for Speed control of DC Shunt motor
Armature Control Method Field Control Method
Field Current: Armature Current:
Armature
Voltage (Va)
Speed
(N)
Field Current
(If)
Speed
(N)
S.No.
Volts RPM Amps RPM
Fuse
Fuse
220VDC SUPPLY
L F A3 POINT STARTER
D
P
S
T
S
250, 2A F
FF
M
A
AA
A
(0-2A)MC
50, 5A
V (0-300V)MC
A
(0-10A)MC
7/27/2019 EC2259 LAB Manual
13/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
Model Graph
(A) Armature Control Method: (B) Field Control Method:
PROCEDURE
Field Control Method (Flux Control Method) Connections are given as per the circuit diagram. Using the three point starter the motor is started to run. The armature rheostat is adjusted to run the motor at rated speed by means of
applying the rated voltage.
The field rheostat is varied gradually and the corresponding field current and speedare noted up to 120% of the rated speed by keeping the Armature current asconstant.
The motor is switched off using the DPIC switch after bringing all the rheostats totheir initial position.
Armature Control Method (Voltage Control Method) Connections are given as per the circuit diagram. Using the three point starter the motor is started to run. The armature rheostat is adjusted to run the motor at rated speed by means of
applying the rated voltage.
The armature rheostat is varied gradually and the corresponding armature voltagearmature current and speed are noted up to the rated voltage.
The motor is switched off using the DPIC switch after bringing all the rheostats totheir initial position
GRAPHThe graph are drawn as
Field current Vs Speed Armature current Vs Speed
RESULTThus the speed control of the given DC shunt motor using field control and armature
control method and its characteristic curves are drawn.
Speedinrpm
Armature Voltage in Volts
Armature Voltage Vs Speed
Speedinrpm Field Current Vs Speed
Field Current in Amps
7/27/2019 EC2259 LAB Manual
14/82
EC2259 Electrical Engineering And Control System Lab Manual
SWINBURNES TEST
AIM
To predetermine the efficiency of a given dc shunt machine when working as a motor as well
as generator by Swinburnes test and also draw the characteristic curves.
NAME PLATE DETAILS
FUSE RATING
10% of rated current (full load current)
APPRATUS REQUIRED
S.NONAME OF THE
APPARATUSTYPE RANGE QUANTITY
1
2
3
4
5
Ammeter
Ammeter
Voltmeter
Rheostat
Tachometer
MC
MC
MC
Wire wound
Digital
(0-2A)
(0-10A)
0-300V
250,2A
1
1
1
1
1
7/27/2019 EC2259 LAB Manual
15/82
EC2259 Electrical Engineering And Control System Lab Manual
CIRCUIT DIAGRAM FOR SWINEBURNS TEST
Tabulation to find out the Constant loss (Wco)
TerminalVoltage (V)
No loadCurrent (I0)
Field Current
(If)
No loadArmature
Current (Ia0)
Constant Loss
WCO= VI0-Ia02Ra
S.No. Volts Amps Amps Amps Watts
Resultant tabulation to find out the Efficiency (Running as motor)
Armature Resistance (Ra)= Rated Current (Ir)=
Constant loss (WC)= Field Current (If) =
LoadCurrent IL=
XIr
ArmatureCurrent
Ia= IL- If
ArmatureCu Loss
WCu=Ia2Ra
TotalLossWTotal
InputPower
Wi=VLIL
Output Power
Wo=Wi- WTotal
Efficiency
= Wo/WiS.No.
Fractionof
Load(X) Amps Amps Watts Watts Watts Watts %
1 1/4
2 1/2
3 3/4
4 1
Fuse
Fuse
220VDC SUPPLY
L F A
3 POINT STARTER
D
P
S
T
S
250, 2AF
FF
M
A
AA
V (0-300V)MC
A
(0-2A)MC
A
(0-10A)MC
7/27/2019 EC2259 LAB Manual
16/82
EC2259 Electrical Engineering And Control System Lab Manual
FORMULAE
1. Armature resistance (Ra) = 1.6 RDC in Ohms.
Where,
RDC Resistance of the Armature coil, when it is energized by DC supply.
2. Constant loss (WCO) = (V Io-Iao2Ra) in Watts..
Where V = Terminal Voltage in Volts
Io = No Load Current in Amps
Iao = No Load Armature Current. in Amps
3. Armature Current (Ia) = (ILIf) in Amps.
Where, + is used for Generator,
- is used for Motor.
4. Copper loss (WCU) = Ia
2
Ra in Watts.5. Total loss = Constant loss + Copper loss in Watts
6. Input power for motor / Output power for generator = V I L in Watts
Where, IL is Load current in Amps
7. Output power for motor = Input power + losses
Input power for Generator = Output power - losses
8. Percentage of Efficiency = (Output power/Input power) 100
PRECAUTION
The motor field rheostat should be kept at minimum resistance position. The motor should be at no load condition through out the experiment. The motor should be run in anticlockwise direction.
PROCEDURE
Connections are given as per the circuit diagram.
By using the three point starter the motor is started to run at the rated speed. The meter readings are noted at no load condition. The motor is switched off using the DPIC switch. After that the Armature resistive test is conducted as per the circuit diagram and the voltage
and current are noted for various resistive loads.
After the observation of readings the load is released gradually.
7/27/2019 EC2259 LAB Manual
17/82
EC2259 Electrical Engineering And Control System Lab Manual
Running as generator
Armature Resistance (Ra)= Rated Current (Ir)=
Constant loss (WC)= Field Current (If)=
LoadCurrent
IL= XIr
ArmatureCurrent
Ia= IL+ If
ArmatureCu Loss
WCu=Ia2Ra
TotalLossWTotal
OutputPower
Wo=VLIL
Input Power
Wi
=Wo+WTotal
Efficiency
= Wo/Wi
S.No.Fraction
ofLoad(X)
Amps Amps Watts Watts Watts Watts %
1 1/4
2 1/2
3 3/4
4 1
7/27/2019 EC2259 LAB Manual
18/82
EC2259 Electrical Engineering And Control System Lab Manual
Model Graph
GRAPH
The graph drawn between Load current Vs Efficiency
RESULT
Thus the efficiency of the given DC shunt machine by Swinburnes test when working as a
motor as well as generator and also draw the characteristic curves are drawn.
Efficiency
Output Power (Wo) in Watts
Generator
Motor
7/27/2019 EC2259 LAB Manual
19/82
EC2259 Electrical Engineering And Control System Lab Manual
OPEN CIRCUIT TEST AND LOAD TEST ON SELF EXCITED DCSHUNT GENERATOR
AIMTo conduct the open circuit test and the load test on a given self excited dc shunt generator anddraw the characteristic curves.
NAME PLATE DETAILS
FUSE RATING
125% of rated current (full load current)
APPRATUS REQUIRED
S.NONAME OF THE
APPARATUSTYPE RANGE QUANTITY
1
2
3
4
5
6
7
Ammeter
Ammeter
Voltmeter
Rheostat
Rheostat
Tachometer
Resistive Load
MC
MC
MC
Wire wound
Wire wound
Digital
Variable
(0-2A)
(0-20A)
(0-300V)
250, 2A
350, 1.5A
-
-
1
2
1
1
1
1
1
PRECAUTION
The motor field rheostat should be kept at minimum resistance position. The generator field rheostat should be kept at maximum resistance position. At the time of starting, the generator should be in no load condition.
7/27/2019 EC2259 LAB Manual
20/82
EC2259 Electrical Engineering And C
Prepared by G.Panne
CIRCUIT DIAGRAM FOR OPEN CIRCUIT AND LOAD TEST ON SELF DC SHUNT GENERATOR
Fuse
M
A
AA
220VDC SUPPLY
L F A
3 POINT STARTER
D
P
S
T
S
250, 2AF
FF
G
A
AA
F
FF
1050,
1.5
A
V(0-300V)
MC
A
(0-2A)MC
A
(0-20A)MC
17
7/27/2019 EC2259 LAB Manual
21/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
PROCEDURE
Open circuit test
Connections are given as per the circuit diagram. The Prime Mover is started with the help of the three point starter and it is made to
run at rated speed when the Generator is disconnected from the load by DPSTswitch.
By varying the Generator field rheostat gradually, the Open Circuit Voltage (Eo)and corresponding Field Current (If) are tabulated upto 150 % of Rated Voltage ofGenerator.
The motor is switched off by using the DPIC switch after bringing all the rheostatsto their initial position.
Load test
Connections are given as per the circuit diagram.
The Prime Mover is started with the help of the three point starter and it is made torun at rated speed when the Generator is disconnected from the load by DPSTswitch.
By varying the Generator field rheostat gradually, the Rated Voltage (Eg) isobtained.
The Ammeter and Voltmeter readings are observed at no load condition. The Ammeter and Voltmeter readings are observed for different loads up to the
rated current by closing the DPST switch.
After tabulating all the readings the load is brought to its initial position gradually. The Prime Mover is switched off using the DPIC switch after bringing all the
rheostats to their initial position.
GRAPH
The graph are drawn as
Open Circuit Voltage Vs Field Current Load Voltage Vs Load Current
7/27/2019 EC2259 LAB Manual
22/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
Tabulation for OC and Load test on self excited DC Shunt Generator
Generator Armature Resistance (Ra):
OC Test Load TestOpen circuit
Voltage(E0)
Field
Current(If)
Load
Voltage(VL)
Load
Current(IL)
Armature
Current(Ia)
Armature
DropIaRa
Generated emf
Eg=VL+ IaRaS.No.
Volts Amps Volts Amps Amps Volts Volts
Model Graph
(A) Open Circuit Characteristics (B) Internal (EgVs Ia) and External (VLVs IL) Characteristics
RESULT
Thus the open circuit test and load test on a given self excited DC generator and thecharacteristic curves are drawn.
OpenCircuitVoltage(E0)
inVolts
Field Current (If) in
Amps
(E0) Vs (If)
LoadVoltage(VL)inVolts
Load Current (IL) in Amps
(VLVs IL)
GeneratedEMF(Eg
)inVo
lts
Armature Current (Ia)
in Amps
(EgVs Ia)
7/27/2019 EC2259 LAB Manual
23/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
OPEN CIRCUIT TEST AND LOAD TEST ON SEPARATELY EXCITEDDC GENERATOR
AIMTo conduct the open circuit test and the load test on a given separately excited dc generator anddraw the characteristic curves.
NAME PLATE DETAILS
FUSE RATING125% of rated current (full load current)
APPRATUS REQUIRED
S.NONAME OF THE
APPARATUSTYPE RANGE QUANTITY
12
3
4
5
6
7
AmmeterAmmeter
Voltmeter
Rheostat
Rheostat
Tachometer
Resistive Load
MCMC
MC
Wire wound
Wire wound
Digital
Variable
(0-2A)(0-20A)
(0-300V)
250, 2A
350, 1.5A
-
-
12
1
1
1
1
1
PRECAUTION
The motor field rheostat should be kept at minimum resistance position. The generator field rheostat should be kept at maximum resistance position. At the time of starting, the generator should be in no load condition.
7/27/2019 EC2259 LAB Manual
24/82
EC2259 Electrical Engineering And
Prepared by G.Panne
CIRCUIT DIAGRAM FOR OPEN CIRCUIT AND LOAD TEST ON SEPERATEDC GENERATOR
220VDC SUPPLY
D
P
S
T
S
350, 1.5A
Fuse
M
A
AA
220VDC SUPPLY
L F A
3 POINT STARTER
D
P
S
T
S
250, 2AF
FF
G
A
AA
V
(0-300V)MC
FF
F
A(0-2A)
MC
A
(0-20A)
MC
23
7/27/2019 EC2259 LAB Manual
25/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
PROCEDURE
Open circuit test
Connections are given as per the circuit diagram. The Prime Mover is started with the help of the three point starter and it is made to run at rated
speed when the Generator is disconnected from the load by DPST switch. By varying the Generator field rheostat gradually, the Open Circuit Voltage (Eo) and
corresponding Field Current (If) are tabulated upto 150 % of Rated Voltage of Generator.
The motor is switched off by using the DPIC switch after bringing all the rheostats to initialposition.
Load test
Connections are given as per the circuit diagram. The Prime Mover is started with the help of the three point starter and it is made to run at rated
speed when the Generator is disconnected from the load by DPST switch..
By varying the Generator field rheostat gradually, the Rated Voltage (Eg) is obtained. The Ammeter and Voltmeter readings are observed at no load condition. The Ammeter and Voltmeter readings are observed for different loads up to the rated current by
closing the DPST switch..
After tabulating all the readings the load is brought to initial position. The motor is switched off using the DPIC switch after bringing all the rheostats to initial position.
GRAPH
The graph drawn as
Open Circuit Voltage Vs Field Current Load Voltage Vs Load Current
7/27/2019 EC2259 LAB Manual
26/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
Tabulation for OC and Load test on separately excited DC Generator
Generator Armature Resistance (Ra):
OC Test Load Test
Open circuitVoltage
(E0)
FieldCurrent
(If)
LoadVoltage
(VL)
LoadCurrent
(IL)
ArmatureCurrent
(Ia)
ArmatureDrop
IaRa
Generated emf
Eg=VL+ IaRaS.No.
Volts Amps Volts Amps Amps Volts Volts
Model Graph
(A) Open Circuit Characteristics (B) Internal (EgVs Ia) and External (VLVs IL) Characteristics
RESULT
Thus the open circuit test and load test on a given separately excited DC generator and thecharacteristic curves are drawn.
OpenCircuitVoltage(E0)
inVolts
Field Current (If) in
Amps
(E0) Vs (If)
LoadVoltage(VL)inVolts
Load Current (IL) in Amps
(VLVs IL)
GeneratedEMF(Eg
)inVolts
Armature Current (Ia)in Amps
(EgVs Ia)
7/27/2019 EC2259 LAB Manual
27/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
LOAD TEST ON SINGLE PHASE TRANSFORMER
AIM
To conduct the load test on a given single phase transformer and draw its performance curves.
NAME PLATE DETAILS
FUSE RATING
Primary Current = KVA Rating of the Transformer / Primary Voltage.
Secondary Current = KVA Rating of the Transformer / Secondary Voltage.
125% of Primary current (fuse rating for primary side)
125% of Secondary current (fuse rating for secondary side)
APPRATUS REQUIRED
S.NONAME OF THE
APPARATUSTYPE RANGE QUANTITY
1
2
3
4
56
Ammeter
Ammeter
Voltmeter
Voltmeter
Watt meter
Auto Transformer
MI
MI
MI
MI
UPF
1
(0-5A)
(0-20A)
(0-150V)
(0-300V)
300V, 5A
230/(0-270V
1
1
1
1
1
1
7/27/2019 EC2259 LAB Manual
28/82
EC2259 Electrical Engineering And
CIRCUIT DIAGRAM FOR LOAD TEST ON SINGLE PHASE TRANSFO
300V, 5A UPF
LM
CP1
P2
150V
A
V (0-300V)MI
A
C
230/(0-270V)1 AUTO
TRANSFORMER
NL
1, 230V, 50HzAC SUPPLY
N
P
Fuse
B
SPSTS
V
(0-1M
1 230/110V, 1KVASTEP DOWN
TRANSFORMER
(0-5A)
MI
S1
S23
3
7/27/2019 EC2259 LAB Manual
29/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
FORMULAE
1. Input Power =Wattmeter reading Multiplication factor in Watts
Where,
Multiplication factor =
2.Output power = VSY ISY cosin Watts.
Where VSY - Secondary Voltage in Volts.
ISY- Secondary current in Amps.
3.Percentage of Efficiency = 100 %
4.Percentage of Regulation = 100 %
Where, VO No Load Voltage in Volts
VL Load Voltage in Volts
PRECAUTION
No Load Condition should be observed at the time of starting Meters are checked for proper Type and rating.
PROCEDURE
Connections are given as per the circuit diagram. The SPST Switch on the Primary side is closed and the DPST Switch on the Secondary side is
opened.
The Autotransformer is adjusted to Energize the transformer with rated Primary Voltage The Volt meters and Ammeters Readings are noted and tabulated at No load condition The DPST switch on the secondary side is closed. The transformer is loaded upto 130% of the Rated Load, corresponding Ammeters, Voltmeters
and Wattmeters readings are noted and tabulated.
After the observation of all the readings the load is released gradually to its initial position. The Autotransformer is brought to its initial position The Supply is switched off.
GRAPH
The graph drawn as
Output power Vs Efficiency Output power Vs Regulation
(Rating of pressure coil Rating of current coil pf )
Full Scale Reading
VO VLVO
Output PowerInput Power
7/27/2019 EC2259 LAB Manual
30/82
EC2259 Electrical Engineering And C
Prepared by G.Pannee
Tabulation for Load test on single phase transformer
Multiplication Factor =
Wattmeterreadings
(W)
PrimaryVoltage
(VPy)
PrimaryCurrent
(IPy)
SecondaryVoltage
(VSy)
SecondaryCurrent
(ISy)
Obs. Act.
Inputpower(W)
Output power
VSyISycosS.No
Volts Amps Volts Amps Watts Watts Watts
7/27/2019 EC2259 LAB Manual
31/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
Model Graph
RESULT
Thus the load test on a given single phase transformer is done and the characteristic curves aredrawn.
%OfEffeciency
Effeciency
Output power in watts
%
OfRegulation
Regulation
7/27/2019 EC2259 LAB Manual
32/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
OPEN CIRCUIT TEST AND SHORT CIRCUIT TEST
ON SINGLE PHASE TRANSFORMER
AIMTo Predetermine the Efficiency and Regulation on a given single phase transformer byconducting the Open Circuit test and Short Circuit test and also draw its Equivalent circuit.
NAME PLATE DETAILS
FUSE RATINGPrimary Current = KVA Rating of the Transformer / Primary Voltage.
Secondary Current = KVA Rating of the Transformer / Secondary Voltage.
10% of Primary current (fuse rating for Open Circuit test)
125% of Secondary current (fuse rating for Short circuit test)
APPARATUS REQUIRED
S.No Name of the apparatus Type Range Quantity
1
2
3
4
56
7
Ammeter
Ammeter
Voltmeter
Voltmeter
Watt meter
Watt meter
Auto Transformer
MI
MI
MI
MI
UPF
UPF
1
(0-1A)
(0-10A)
(0-150V)
(0-300V)
300V, 1A
75V, 5A
230/(0-270V)
1
1
1
1
1
1
1
7/27/2019 EC2259 LAB Manual
33/82
EC2259 Electrical Engineering And
Prepared by G.Panne
CIRCUIT DIAGRAM FOR OPEN CIRCUIT TEST ON SINGLE PHASE TRA
1, 230V, 50HzAC SUPPLY
A
C
230/(0-270V)1 AUTO
TRANSFORMER
NL
N
P
Fuse
B
SPSTS150V
150V, 5A LPF
LM
C
A
V (0-150V)MI
1 110/2STE
TRANS
P1
P2
(0-5A)MI
39
7/27/2019 EC2259 LAB Manual
34/82
EC2259 Electrical Engineering And C
Prepared by G.Panne
CIRCUIT DIAGRAM FOR SHORT CIRCUIT TEST ON SINGLE PHASE TRA
(0-75V)MI
75V
300V, 10A UPF
LM
C
A
V
A
C
230/(0-270V)1 AUTO
TRANSFORMER
NL
1, 230V, 50HzAC SUPPLY
N
P
Fuse
B
SPSTS
P1
P2
(0-5A)MI
1 230/11STEP
TRANSF
41
7/27/2019 EC2259 LAB Manual
35/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
Tabulation for OC and SC test on Single phase transformer
Open Circuit test Multiplication Factor =
Short
Circuit testMultiplication Factor =
Short Circuit power (WSC)Short CircuitPrimary
Current (ISC)
Short circuitPrimary
Voltage (VSC)Obs. Act.
Short Circuitsecondary
Current (I2S)S.No.
Amps Volts Watts Watts Volts
Resultant Tabulation to find out the Efficiency
Core (Or) Iron Loss = A Rating of Transformer =Rated Short Circuit Current (ISC) = Short Circuit Power (WSC) =
Output powerShortcircuitCurrent
(ISCX)0.2 0.4 0.6 0.8 1
CopperLoss
(X2WSC)
Total LossWT =
Wi+WSC
EfficiencyO/p
O/p+TLFraction ofLoad (X)
Amps Watts Watts Watts %
1/4
1/2
3/4
1
Open Circuit power (WOC)Open CircuitPrimaryCurrent (IOC)
Open circuitPrimaryVoltage (VOC) Obs. Act.
Open CircuitsecondaryVoltage (V2O)
S.No.
Amps Volts Watts Watts Volts
=
7/27/2019 EC2259 LAB Manual
36/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
FORMULAE
EQUIVALENT CIRCUIT
Open Circuit Test
1. No Load Power Factor (Coso) =
Where, Woc Open Circuit Power in Watts
Voc Open Circuit Voltage in Volts
Ioc Open Circuit Current in Amps
2.No Load Working Component Resistance (Ro) = in Ohms
Where Voc Open Circuit Voltage in Volts.
Ioc Open Circuit current in Amps.
3. No Load Magnetizing Component Reactance( Xo) = in Ohms
Where Voc Open Circuit Voltage in Volts.
Ioc Open Circuit current in Amps.
Short Circuit Test
4. Equivalent impedance referred to HV side ( Z02) = in Ohms
Where, Vsc Short circuit Voltage in Volts
Isc Short circuit current in Amps
5. Equivalent resistance referred to HV side (R02) = in Ohms
Where, Wsc Short circuit Power in Watts
6. Equivalent reactance referred to HV side (X02) =Z022- R022 in Ohms
7. Transformation ratio (K) =
Where, V1 Primary voltage in Volts
V2 Secondary Voltage in Volts
8. Equivalent resistance referred to LV side (R01)= in Ohms
9. Equivalent reactance referred to LV side (X01)= in Ohms
Efficiency and Regulation
10. Output Power = X KVA cosin Watts.Where, X-Fraction of load
KVA - power rating of Transformer and Cos- Power factor
VscIsc
WocVoc Ioc
Voc
Ioc Coso
Voc
Ioc Sino
WscIsc2
V2V1
R02K2
X02K2
7/27/2019 EC2259 LAB Manual
37/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
11. Copper loss = X2 Wsc in WattsWhere, Wsc- Copper Loss in Short Circuit condition
12. Total Loss = (Cu Loss + Iron Loss) in Watts
13. Efficiency = x 100 in %
14. Regulation = 100 in %
Where, V2o Open Circuit Voltage on HV side.
PRECAUTION
No Load Condition should be observed at the time of starting Meters are checked for proper Type and rating.
PROCEDURE
OPEN CIRCUIT TEST
Connections are given as per the circuit diagram. The SPST Switch on the Primary side is closed. The Autotransformer is adjusted to Energize the transformer with rated Primary Voltage
on the LV side
The Volt meter, Watt meter and Ammeter Readings are noted at No load condition The Autotransformer is brought to its initial position
The Supply is switched off.
SHORT CIRCUIT TEST
Connections are given as per the circuit diagram. The SPST Switch on the Primary side is closed The Autotransformer is adjusted to energize the transformer with rated Primary Current on
the HV side.
The Voltmeter, Wattmeter and Ammeter Readings are noted down at short circuitcondition.
The Autotransformer is brought to its initial position The Supply is switched off.
GRAPH
The graph are drawn as
Output power Vs Efficiency Output power Vs Regulation
Output power
(Output power +Total Losses)
X Isc [R02 x cos X02 x sin]V2o
7/27/2019 EC2259 LAB Manual
38/82
EC2259 Electrical Engineering And
Prepared by G.Pann
Resultant Tabulation to find out the Regulation
ISC = RO2= XO2 = % Of Reg
Value of Cos Value of Sin 0.8 0.6 Fractionof Load
(X) 1 0.8 0.6 0.4 0.2 1 0.8 0.6 0.4 0.2 1 Lag. Lead. Lag. Lead
7/27/2019 EC2259 LAB Manual
39/82
7/27/2019 EC2259 LAB Manual
40/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
LOAD TEST ON THREE PHASE SQUIRREL CAGEINDUCTION MOTOR
AIM
To conduct a load test on a three phase squirrel cage induction motor and to draw the
performance characteristic curves.
NAME PLATE DETAILS
! " "#$%"&'"
FUSE RATING
125% of rated current (Full load current)
APPARATUS REQUIRED
FORMULAE USED
1.Torque = (S1-S2) (R+t/2) x 9.81 N-m
Where, S1, S2 spring balance readings in Kg.
R - Radius of brake drum in m.
t - Thickness of belt in m.
2. Output Power = 2 NT/60 watts.
N- Rotor speed in rpm.
T- Torque in N-m.
S.NONAME OF THE
APPARATUSTYPE RANGE QUANTITY
1.2.
3.4.
AmmeterVoltmeter
WattmeterTachometer
MIMI
UPF-
(0-10 A)(0-600 V)
(500V, 10A)-
11
1
1
3. Input Power = (W1+W2) Watts.
W1, W2 Wattmeter readings in Watts.
7/27/2019 EC2259 LAB Manual
41/82
EC2259 Electrical Engineering And
Prepared by G.Panne
CIRCUIT DIAGRAM FOR LOAD TEST ON THREE PHASE SQUIRRAL CAGE IN
(0-10) AMI
15V, 50Hz, 3AC SUPPLY
R
Y
B
N
STAR-DELTASTARTER
A
T
P
S
TS
Fuse
Fuse
Fuse
V (0-600) VMI
600V, 10A UPF
L
600V
M
C
R
STATOR
A1
A2
B1
M
600V, 10A UPF
C
L
600V
A1
A2
B1
B2
C1
C2
L2
L3
L1
NLN
51
7/27/2019 EC2259 LAB Manual
42/82
EC2259 Electrical Engineering And Control System Lab Manua
Prepared by G.Panneerselvam, Vel Tech Multi Tec
4. Percentage of Efficiency = (Output Power/ Input Power) x 100%.
5. Percentage of Slip = (NS-Nr)/Nsx 100%
Ns-Synchronous speed in rpm.
Nr-Rotor speed in rpm.
6.Power factor = (W1+W2)/3 VLIL.
PRECAUTION
The motor should be started without any load
PROCEDURE:
Connections are given as per the circuit diagram. The TPSTS is closed and the motor is started using On Line starter to run at rated speed. At no load the speed, current, voltage and power are noted down. By applying the load for various values of current the above-mentioned readings are noted. The load is later released and the motor is switched off and the graph is drawn. .
GRAPH
The graph are drawn as
Output Power Vs Speed
Output Power Vs Line current Output Power Vs Torque Output Power Vs Power factor Output Power Vs % Efficiency Output Power Vs % Slip.
7/27/2019 EC2259 LAB Manual
43/82
EC2259 Electrical Engineering And
Prepared by G.Pannee
Tabulation for load test on three phase squirrel cage induction m
Multipl
Wattmeter readings
W1 W2
Inputpower
Spring balancereading
LoadCurren
t(IL)
LoadVoltage
(VL)
Obs. Act. Obs. Act.W1+W2
Speedof themotor(N)
S1 S2 S1~S2
Torque (T(S1~S2) (R+t
(9.81)S.No
Amps Volts Watts Watts rpm Kg Kg Kg N-m
7/27/2019 EC2259 LAB Manual
44/82
EC2259 Electrical Engineering And Control System Lab Manua
Prepared by G.Panneerselvam, Vel Tech Multi Tech
Load test on Three phase squirrel cage induction motor
Model Graphs:
(A) Mechanical characteristics
(B) Electrical characteristics:
RESULT
Thus the load test on a given three phase squirrel cage induction motor is done and th
characteristic curves are drawn.
Speed in RPM
Torque in N-m
Torque Vs Speed
O/P powerin watts
N
N in rpm
ILin Amps
T in N-m
%T
IL %
Cos
Cos
7/27/2019 EC2259 LAB Manual
45/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
EQUIVALENT CIRCUIT OF THREE PHASE SQUIRREL CAGEINDUCTION MOTOR
AIM
To conduct a No Load test and Blocked Rotor test on three phase squirrel cage induction motorand to draw the equivalent circuit.
NAME PLATE DETAILS
! " "#$%"&'"
FUSE RATING
No Load: 10 % of rated current (Full load current)
Load: 125 % of rated current (Full load current)
APPARATUS REQUIRED
FORMULAE USED
OC Test
1. No load power factor (Cos 0) = P0/V0I0
V0- No load voltage per phase in volts.
I0- No load current per phase in amps.
P0 - No load power per phase in watts.
2. Working component current (Iw) = I0 (ph) X Cos 0
3. Magnetizing current (Im) = I0 (ph) X Sin 0
4. No load resistance (R0) =V0/I0 (ph) Cos 0 in.
S.NO. NAME OF THE
APPARATUS
TYPE RANGE QUANTITY
1.2.
3.4.5.6.7.
AmmeterAmmeter
VoltmeterVoltmeterVoltmeterWattmeterWattmeter
Tachometer
MCMI
MIMIMCLPFUPF
-
(0-10 A)(0-10 A)
(0-150 V)(0-600 V)(0-50 V)
(600V, 10A) (150V,10A)
-
12
111221
7/27/2019 EC2259 LAB Manual
46/82
EC2259 Electrical Engineering And
Prepared by G.Panne
CIRCUIT DIAGRAM FOR NO LOAD TEST ON THREE PHASE SQUIRRINDUCTION MOTOR
(Equivalent circuit)
57
415V, 50Hz, 3AC SUPPLY
R
YB2
B
T
P
ST
S
N
A1
A3
B3
V (0-600) VMI
A2
B1
Fuse
415 / (0-470) V3 AUTO TRANSFORMER
A
(0-10) AMI
600V, 10A LPF
600V
C2
C3
C1
A2
B1
LM
C
M
600V, 10A LPF
C
L
600V
Fuse
Fuse
NL
7/27/2019 EC2259 LAB Manual
47/82
EC2259 Electrical Engineering And
Prepared by G.Panne
CIRCUIT DIAGRAM FOR BLOCKED ROTOR TEST ON THREE PHASE SQUINDUCTION MOTOR(Equivalent circuit)
59
A1
A3
B3
Fuse
A2
415 / (0-470) V3 AUTO TRANSFORMER
C2
C3
C1
Fuse
Fuse
NL
B1
B2
R415V, 50Hz, 3AC SUPPLY
R
Y
B
T
P
S
TS
N
V (0-150) VMI
STATOR
A(0-10) A
MI
150V, 10A UPF
L
150V
M
C
M
150V, 10A UPF
C
L
150V
A1
A2
B1
C
7/27/2019 EC2259 LAB Manual
48/82
EC2259 Electrical Engineerin
Prepared by G
Tabulation for No Load test on three phase Squirrel cage Induct
Speed of theType of the
Mu
Tabulation for Blocked rotor test on three phase Squirrel cage InduType of the Stator conne
Multiplication F
Short Circuit Power
W1 W2
ShortCircuitCurrent
(ISC)
ShortCircuitVoltage(VSC)
Observed Actual Observed Actual
Total ShortCircuit PowerPSC=(W1+W
2)
Short CircuitPower/Phase
PSC
(Ph)=(P0/3)
S.No
Amps Volts Watts Watts Watts Watts Watts Watts
No Load Power
W1
W2
No Load
Current(I0)
No Load
Voltage(V0)
Observed Actual Observed Actual
Total No Load Power
P0=(W1+W2)
No Load Power/Phase
P0 (Ph)=(P0/3)
S.No
Amps Volts Watts Watts Watts Watts Watts Watts
7/27/2019 EC2259 LAB Manual
49/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
5. No load reactance (X0) = V0/I0(ph) Sin 0 in .
SC Test
6. Motor equivalent Impedance referred to stator (Zsc(ph)) = Vsc(ph)/ Isc(ph) in.
7. Motor equivalent Resistance referred to stator (Rsc(ph)) = Psc(ph) / I2sc(ph) in.
8. Motor equivalent Reactance referred to stator (Xsc(ph)) = (Z sc(ph)2- R sc(ph)2) in.
9. Rotor Resistance referred to stator (R2(ph)) = Rsc(ph) R1 in.
10. Rotor Reactance referred to stator (X2(ph)) = Xsc(ph)/ 2 = X1 in.
Where R1 -stator resistance per phase
X1 stator reactance per chapter
R1 = R(ac) =1.6 x R(dc)
11. Equivalent load resistance (RL)= R2 (1/s 1) in .
Where Slip (S) = (Ns-Nr) / Ns
Ns Synchronous speed in rpm.
Nr Rotor speed in rpm.
PRECAUTION
The autotransformer should be kept at minimum voltage position
PROCEDURE
Connections are given as per the circuit diagram.
For No-Load or open circuit test by adjusting autotransformer, apply rated voltage and
Note down the ammeter and wattmeter readings. In this test rotor is free to rotate.
For short circuit or blocked rotor test by adjusting autotransformer, apply rated current
and note down the voltmeter and wattmeter readings. In this test rotor is blocked.
After that make the connection to measure the stator resistance as per the circuit diagram.
By adding the load through the loading rheostat note down the ammeter, voltmeter
reading for various values of load.
7/27/2019 EC2259 LAB Manual
50/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
Equivalent circuit for three phase squirrel cage induction motor
RESULT
Thus the no load and blocked rotor test on a given three phase squirrel cage induction motor and
the equivalent circuit is drawn.
P
N
1, 230V, 50Hz ACSupply
R2'X
2'
RL' =R2' (1/s-1)
R1 X1
X0R0
I0
Iw I
7/27/2019 EC2259 LAB Manual
51/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
REGULATION OF THREE PHASE ALTERNATOR BY EMF AND MMFMETHODS.
AIM
To predetermine the regulation of a given three phase Alternator by EMF and MMF method and also draw thevector diagrams.
NAME PLATE DETAILS
('"#" ) "
FUSE RATING
125% of rated current (Full load current)
For DC shunt motor:
For Alternator:
APPARATUS REQUIRED
S.NO.NAME OF THE
APPARATUSTYPE RANGE QUANTITY
1.2.3.4.5.6.7.
8.
AmmeterAmmeterAmmeterVoltmeterVoltmeterRheostatRheostat
Tachometer
MCMCMIMIMC
Wire WoundWire Wound
-
(0-2 A)(0-10 A)(0-10 A)(0-600V)(0-50V)
(500, 1.2A)(300, 1.7A)
-
1111121
1
7/27/2019 EC2259 LAB Manual
52/82
EC2259 Electrical Engineer
Prepared by
CIRCUIT DIAGRAM FOR REGULATION OF THREE PHASE ALTBY EMF & MMF METHOD
(Open circuit and Short circuit tests)
V
220VDCSUPPLY
L F A
3 POINT STARTER
D
P
S
T
S
250, 2A
M
F
FF
A
AA
(0-600) VMI
XXX
R
B YN
A(0-2) A
MC
Fuse
Fuse
220VDC SUPPLY
D
P
S
T
S
350, 1.5A
79
7/27/2019 EC2259 LAB Manual
53/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
FORMULAE USED
EMF Method1. Armature Resistance Ra = 1.6 Rdc in ohms.
Here, Rdc is the resistance in DC supply.
2. Synchronous impedance Zs = (from the graph)
3. Synchronous impedance Xs =(Zs -Ra) in ohms.
4. Open circuit voltage Eo=(V cos + Isc Ra) + (V sin -Isc Xs) in Volts.(For lagging power factor)
5. Open circuit voltage Eo=(V cos + Isc Ra) + (V sin -Isc Xs) in Volts(For leading power factor)
7. Open circuit voltage Eo=(V + Isc Ra) + (Isc Xs) in Volts(For Unity power factor)
6. Percentage regulation =
PRECAUTION
The motor field rheostat should be kept in the minimum resistance position. The Alternator field Potential divider should be in the maximum voltage position. Initially all Switches are in open position.
PROCEDURE FOR BOTH EMF AND MMF METHOD
Connections are made as per the circuit diagram. Give the supply by closing the DPST Switch. Using the Three Point starter, start the motor to run at the synchronous speed by varying the
motor field rheostat.
Conduct an Open Circuit Test by varying the Potential Divider for various values of FieldCurrent and tabulate the corresponding Open Circuit Voltage readings.
Conduct a Short Circuit Test by closing the TPST switch and adjust the potential divider toset the rated Armature Current, tabulate the corresponding Field Current.
Conduct a Stator Resistance Test by giving connection as per the circuit diagram andtabulate the Voltage and Current readings for various resistive loads.
Open circuit voltage (E1 (ph))Short circuit current (Isc)
Eo VratedVrated X 100 (both for EMF & MMF method)
7/27/2019 EC2259 LAB Manual
54/82
EC2259 Electrical Engineering And Control System Lab Manua
Prepared by G.Panneerselvam, Vel Tech Multi Tech
PROCEDURE TO DRAW THE GRAPH FOR EMF METHOD
Draw the Open Circuit Characteristics curve (Generated Voltage per phase Vs Field Current). Draw the Short Circuit Characteristics curve (Short Circuit Current Vs Field Current). From the graph find the open circuit voltage per phase (E1 (Ph)) for the rated Short Circuit Current
(Isc).
By using respective formulae find the Zs, Xs, Eoand percentage Regulation.
PROCEDURE TO DRAW THE GRAPH FOR MMF METHOD
Draw the Open Circuit Characteristics curve (Generated Voltage per phase Vs Field Current). Draw the Short Circuit Characteristics curve (Short Circuit Current Vs Field Current). Draw the line OL to represent If'which gives the rated generated voltage (V). Draw the line LA at an angle(90 )to represent If''which gives the rated full load current (Isc)
on short circuit ((90 +) for lagging power factor and(90-) for leading power factor).
Join the points O and A and find the field current (If) by measuring the distance OAthat gives theOpen Circuit Voltage (Eo) from the Open Circuit Characteristics.
Find the percentage Regulation by using suitable formula.
Tabulation for Regulation of three phase Alternator by EMF and MMF methods
Open circuit test
Field Current(If)
Open Circuit LineVoltage (V0L)
Open Circuit PhaseVoltage(V0 (Ph))S.No.
Amps Volts Volts
7/27/2019 EC2259 LAB Manual
55/82
EC2259 Electrical Engineering And Control System Lab Manua
Prepared by G.Panneerselvam, Vel Tech Multi Tech
Short circuit test
Regulation of three phase Alternator by EMF and MMF methods
Model Graph for EMF Method
Field Current(If)
Short Circuit Current(120 to 150 % of rated current)
(ISC)
S.No.
Amps Amps
OCC
E1 (ph)
Field Current (If) in Amps
ShortCircuitCurrent(ISC)inAmps
OpenCircuitVoltage(V0(Ph))inVolts
SCC
7/27/2019 EC2259 LAB Manual
56/82
EC2259 Electrical Engineering And Control System Lab Manua
Prepared by G.Panneerselvam, Vel Tech Multi Tech
Regulation of three phase Alternator by EMF and MMF methods
Model Graph for MMF Method
SCC
OCC
E0 (ph)Lead.
Field Current (If) in Amps
ShortCircui
tCurrent(ISC)inAmps
OpenCircuitVoltage(V0(Ph))inVolts
O L
A
A
A
E0 (ph)Unity
E0 (ph)Lag.
Lead.Lag.
Unity
90- 90+
7/27/2019 EC2259 LAB Manual
57/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
Resultant Tabulation for Regulation of three phase Alternator by EMF and MMFmethods
Regulation curve of Alternator (EMF, MMF and Vector diagram)
RESULT
Thus the regulation of three phase alternator by EMF and MMF methods and the regulation curves aredrawn.
Percentage of Regulation
EMF Method MMF MethodS.No. PowerFactor Lagging Leading Unity Lagging Leading Unity
1. 0.2 - -
2. 0.4 - -
3. 0.6 - -
4. 0.8 - -
5. 1.0
Lagging pf
Leading pf
+%
Regulation
-
%Regulation
From EMF method
From MMF method
Unity pf
7/27/2019 EC2259 LAB Manual
58/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
STABILITY ANALYSIS OF LINEAR SYSTEM
AIM
To analysis the stability of the given linear system using Bode Plot, Nyquist Plot and Root Locus.
APPRATUS REQUIRED
S.No Name of the apparatus Type Range Quantity
1
2
Computer
MATLAB Software
-
-
-
-
1
1
THEORY
POLAR PLOT
The polar plot of a sinusoidal transfer function ( )G j on polar coordinates as is varied from zero to
infinity. Thus the polar plot is the locus of vectors ( )G jw and ( )G jw as is varied from zero to infinity. The
polar plot is also called Nyquist plot.
NYQUIST STABILITY CRITERION
If ( ) ( )G s H s contour in the ( ) ( )G s H s plane corresponding to Nyquist contour in s-plane encircles the
point 1 0j + in the anti clockwise direction as many times as the number of right half s-plane of ( ) ( )G s H s .
Then the closed loop system is stable.ROOT LOCUS
The root locus technique is a powerful tool for adjusting the location of closed loop poles to achieve
the desired system performance by varying one or more system parameters.
The path taken by the roots of the characteristics equation when open loop gain K is varied from 0 to
are called root loci (or the path taken by a root of characteristic equation when open loop gain K is varied
from 0 to is called root locus.)
FREQUENCY DOMAIN SPECIFICATIONS
The performance and characteristics of a system in frequency domain are measured in term of frequency
domain specifications. The requirements of a system to be designed are usually specified in terms of these
specifications.
7/27/2019 EC2259 LAB Manual
59/82
7/27/2019 EC2259 LAB Manual
60/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
PROCEDURE
Enter the command window of the MATLAB.
Create a new M file by selecting File New M File.
Type and save the program.
Execute the program by either pressing F5 or Debug Run. View the results.
Analysis the stability of the system for various values of gain.
PROBLEM
Obtain the Bode Plot, Nyquist Plot and Root Locus of the given open loop T.F is2
3
2( )
2H s
s s+=
+
Using Bode Plot
num = [0 0 2]den = [1 3 2]bode (num,den)gridtitle (BODE DIAGRAM)% To Find out Gain Margin
sys = tf (num, den)bode (sys)Margin (sys)[ gm, ph, wpc, wgc ] = margin (sys).
Using Nyquist Plot
num = [0 0 2]den = [1 3 2]nyquist (num,den)gridtitle (Nyquist Plot)
Using Nyquist Plot
num = [0 0 2]den = [1 3 2]rlocus (num,den)gridtitle (Root Locus Plot)
RESULT
Thus the stability of the given linear system using Bode Plot, Nyquist Plot and Root Locus was
analyzed.
7/27/2019 EC2259 LAB Manual
61/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
DIGITAL SIMULATION OF LINEAR SYSTEM
AIM
To simulate the time response characteristics of second order linear system using
MATLAB.
APPRATUS REQUIRED
S.No Name of the apparatus Type Range Quantity
1
2
Personal Computer
MATLAB Software
-
-
-
-
1
1
THEORYThe desired performance characteristics of control system are specified in terms of time
domain specification. Systems with energy storage elements cannot respond instantaneously and
will exhibit transient responses, whenever they are subjected to inputs or disturbances.
The desired performance characteristics of a system pf any order may be specified in
terms of the transient response to a unit step input signal.
The transient response of a system to unit step input depends on the initial conditions.
Therefore to compare the time response of various systems it is necessary to start with standard
initial conditions. The most practical standard is to start with the system at rest and output andall time derivatives there of zero. The transient response of a practical control system often
exhibits damped oscillations before reaching steady state.
The transient response characteristics of a control system to a unit step input are
specified in terms of the following time domain specifications.
1. Delay timed
t
2. Rise timer
t
3. Peak timep
t
4. Maximum overshootp
M
5. Settling times
t
1. Delay Time
It is the taken for response to reach 50% of the final value, for the very first time.
7/27/2019 EC2259 LAB Manual
62/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
2. Rise Time
It is the time taken for response to raise from 0 to 100% for the very first time. For under
damped system, the rise time is calculated from 0 to 100%. But for over damped system it is the
time taken by the response to raise from 10% to 90%. For critically damped system, it is the
time taken for response to raise from 5% to 95%.
Rise timer d
t
=
Where,211
tan
=
and
Damped frequency of oscillation 21nd =
3. Peak Time
It is the time taken for the response to reach the peak value for the very first time. (or) It is the
taken for the response to reach the peak overshootpt .
Rise timep dt
=
4. Peak Overshoot (Mp)
It is defined as the ration of the maximum peak value measured from final value to the final
value.
Let final value ( )c e=
Maximum vale ( )c tp
=
Peak Overshoot,p
M( ) ( )
( )
c t c ep
c e
=
21% 100M e
p
=
5. Settling Time
It is defined as the time taken by the response to reach and stay within a specified error. It is
usually expressed as % of final value. The usual tolerable error is 2% or 5% of the final value.
Settling Time4
s nt
= (For 2% error).
Settling Time3
s nt
= (For 5% error).
7/27/2019 EC2259 LAB Manual
63/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
PROCEDURE
Enter the command window of the MATLAB.
Create a new M file by selecting File New M File.
Type and save the program.
Execute the program by either pressing F5 or Debug Run.
View the results.
Analysis the time domain specifications of the system.
PROBLEM
Obtain the time domain specifications of the given open loop T.F is2
2
100( )
100H s
s s+=
+
MATLAB PROGRAM FOR UNIT IMPULSE PRSPONSE
num = [ 0 0 100 ]
den = [ 1 2 100 ]
impulse (num, den)
grid
title ( unit impulse response plot)
MATLAB PROGRAM FOR UNIT STEP PRSPONSEnum = [ 0 0 100 ]
den = [ 1 2 100 ]
step (num, den)
grid on
title (unit step response plot)
RESULT
Thus the time response characteristic of second order linear system was verified using
MATLAB.
7/27/2019 EC2259 LAB Manual
64/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
DESIGN OF P, PI, PID CONTROLLER
AIM
To design P, PI, and PID controllers for first order systems using MATLAB.
APPARATUS REQUIRED1. Controller and system kit.
2. Patch chords.
3. Computer and Interference chord.
THEORY
Proportional Controller
1. The Proportional Controller is a device that produces the control signal, u (t) which is
Proportional to the input error signal e (t).
In P controller, u (t) e (t).
Therefore u (t) = Kp c (t).
Where Kp Proportional gain or constant.
2. The Proportional plus Integral Controller (PI Controller) produces an output signal
consisting of two terms one on proportional to error signal and the other proportional to
the integral of error signal
In PI Controller, u (t) [e (t) + | e (t) dt]
Therefore, u (t) = e (t) + Kp / Ti | e (t) dt
Where Kp Proportional gain or constant,
Ti Integral Time.
3. The PID Controller produces an output signal consisting of three terms one on
proportional to error signal and the another one proportional to the integral of error
signal and the third one is proportional to derivative of error signal.
In PID Controller, u (t) [e (t) + | e (t) + d /dt ((e (t))]
Therefore, u (t) = e (t) + Kp / Ti | e (t) dt + Kp Td d /dt ((e(t))]
Where Kp Proportional gain or constant,
Ti Integral Time.
Td Derivative Time.
7/27/2019 EC2259 LAB Manual
65/82
EC2259 Electrical Engineering
Type 0 First Order System with P Controller
Computer CH 0 Computer CH 1
Step Input
(FG)
P Controller
Level ShifterLevel Shifter
7/27/2019 EC2259 LAB Manual
66/82
EC2259 Electrical Engineering
Type 0 First Order System with PI - Controller
Computer CH 0 Computer CH 1
Step Input
(FG)
PI Controller
Level ShifterLevel Shifter
7/27/2019 EC2259 LAB Manual
67/82
EC2259 Electrical Engineering
Type 0 First Order System with PID - Controller
Computer CH 0 Computer CH 1
Step Input
(FG)
PID Controller
Level ShifterLevel Shifter
7/27/2019 EC2259 LAB Manual
68/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
Procedure
Type 0 First Order System with P Controller
1. Connections are given as per the circuit diagram.
2. Set Proportional Band = 80, Integral Time = 64000 and Derivative Time = 0.
3. Measure the performance specifications.
Type 0 First Order System with PI Controller
1. Connections are given as per the circuit diagram.
2. Set Proportional Band = 80, Integral Time = 30 and Derivative Time = 0.
3. Measure the performance specifications.
Type 0 First Order System with PI Controller
1. Connections are given as per the circuit diagram.
2. Set Proportional Band = 80, Integral Time = 30 and Derivative Time = 0.1.
3. Measure the performance specifications.
Transfer Function for P, PI, and PID Controller:
P Controller: Transfer Function = Kp
PI Controller: Transfer Function = Kp [1 + 1 / Ti S]
PID Controller: Transfer Function = Kp [1 + 1 / Ti S + Td S]
TABULAR COLUMN
S. No Time Domain Specification P controller PI controller PID controller
7/27/2019 EC2259 LAB Manual
69/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
Model Graph
RESULT
Thus the design of P, PI and PID controller was done.
7/27/2019 EC2259 LAB Manual
70/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
DESIGN OF LAG AND LEAD COMPENSATOR
AIM
To design and implement the suitable lag and lead compensator for a given linear system
to improve the performance.APPARATUS REQUIRED
1. Transfer function and compensator
2. Computer interface chord
3. Patch chords
THEORY
LAG COMPENSATOR
A compensator having the characteristics of a Lag network is called a lag
compensator. If a sinusoidal signal is applied to a lag network, then in steady state the output
will have a phase lag with respect to input.
Lag compensation results in a large improvement in steady state performance but
results in slower response due to reduced bandwidth. The attenuation due to the lag compensator
will shift the gain cross over frequency to a lower frequency point where the phase margin is
acceptable.
The general form of lag compensator transfer function is given by:
G(S) = (S+T) / (S+P) = (S + 1/T) / S + 1/BT Where, T > 0 and B >1
LEAD COMPENSATOR
A compensator having the characteristics of a Lead network is called a Lead
compensator. If a sinusoidal signal is applied to the lead network, then in steady state the output
will have a phase lead with respect to input.
Lead compensation increases the bandwidth, which improves the speed of
response and also reduces, whereas there is a small change in steady state accuracy. Generally,
Lead compensation is provided to make an unstable system as a stable system.
A Lead compensator is basically a high pass filter so it attenuates high frequency
noise effects. If the pole introduced by the compensator is not cancelled by a zero in the system,
then lead compensation increases the order of the system by one.
The general form of Lead compensator transfer function is given by:
G(S) = (S+T) / (S+P) = (S + 1/T) / S + 1/aT Where, T > 0 and a
7/27/2019 EC2259 LAB Manual
71/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
Type II Order System Performance
Without Lag Compensator
1. Connections are given as per the circuit diagram.
2. Switch on the power supply.
3. Apply step input.
4. Set Pb = 100%
5. Measure the time domain specification of the II order system from the waveform.
With Lag Compensator
1. Connections are given as per the circuit diagram.
2. Switch on the power supply.
3. Apply step input.
4. Set Pb = 100%
5. Measure the time domain specification of the II order system from the waveform.
6. Compare the performance with and without lag compensator.
TABULAR COLUMN
S. No Time Domain Specification Without Lag With Lag
PROCEDURE
7/27/2019 EC2259 LAB Manual
72/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
Type II Order System Performance
Without Lead Compensator
1. Connections are given as per the circuit diagram.
2. Switch on the power supply.
3. Apply step input.
4. Set Pb = 100%.
5. Measure the time domain specification of the I order system from the waveform.
With Lead Compensator
1. Connections are given as per the circuit diagram.
2. Switch on the power supply.
3. Apply step input.
4. Set Pb = 100%
5. Measure the time domain specification of the I order system from the waveform.
6. Compare the performance with and without Lead compensator.
TABULAR COLUMN
S. No Time Domain Specification Without Lead With Lead
7/27/2019 EC2259 LAB Manual
73/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
Model Graph (Lead Compensator)
Model Graph (Lead Compensator)
RESULT: Thus the lag and lead compensator of the given system is implemented and the
performance was compared.
7/27/2019 EC2259 LAB Manual
74/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
TRANSFER FUNCTION OF SEPARATELY EXCITED
DC SHUNT GENERATOR
AIM
To determine the transfer function of the given Separately Excited DC Shunt generator.
NAME PLATE DETAILS
FUSE RATING
Motor:125% of full load current (rated current)
Generator:125% of full load current (rated current)
APPARATUS REQUIRED
S.No Name of the apparatus Type Range Quantity
1
2
3
4
5
6
7
8
Ammeter
Ammeter
Ammeter
Voltmeter
Voltmeter
Rheostat
Rheostat
Single Phase Variac
MC
MC
MI
MC
MI
Wire wound
Wire wound
-
(0-10A)
(0-2A)
(0-300mA)
(0-300V)
(0-300V)
250, 2A
350, 1.5A
230V/ (0-270V)
1
1
1
1
1
1
1
1
7/27/2019 EC2259 LAB Manual
75/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
FORMULAE
1.Generated EMF Constant (Kg) = Eg / Ifin Volts / Amps (From the Graphs)
2. Field Resistance (Rf) = Vf/ If
3. Effective Resistance (Reff) = VL/ IL inVolts / Amps (From the Graphs)
Where, VL = Change in load voltage in volts
IL = Change in load current in amps
4. Load Resistance (RL) = PL/ IL2
Where, RL =Load Resistance in Ohms
PL = Power of Load in Watts
IL = Total Load current in Amps
5. Field Inductance Lf
Where, Xf=(Zf2Rf
2)
Xf= 2f Lf
Lf= Xf/ 2f
f = frequency of applied source in hertz
6.Transfer function
Eg(s) Ef(s) = (No Load)
Vt (s) / Ef(s) = (Load)
PRECAUTION
1. The motor field rheostat should be kept at minimum resistance position.
2. The motor armature rheostat should be kept at maximum resistance position.
3. At the time of starting, the motor should be in no load condition.
(Kg/ Rf)
(1+ (Lf/ Rf) S) (1+ (Reff/ RL))
(Kg/ Rf)
(1+ (Lf/Rf) S)
7/27/2019 EC2259 LAB Manual
76/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
PROCEDURE
To find out Generated EMF Constant (Kg)
1. Connections are given as per the circuit diagram.
2. The motor is made to run at the rated speed.
3. The generated emf is noted for various values of field current.
4. The voltage across the field winding is also measured
5. From the OCC curve Back Emf constant is calculated.
To find out Field Impedance (Zf)
1. Connections are given as per the circuit diagram.
2. Using single phase variac the supply voltage is varied.
3. The corresponding reading of field currentis noted for different values of applied voltage.
4. From the noted readings the field Impedance is calculated.
RESULT
Thus the transfer function of separately excited DC shunt generator is determined.
7/27/2019 EC2259 LAB Manual
77/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
TRANSFER FUNCTION OF ARMATURE AND FIELDCONTROLLED DC SHUNT MOTOR
AIM
To determine the transfer function of the given armature and field controlled DC shuntmotor.
NAME PLATE DETAILS
FUSE RATING:
125% of rated current (full load current)
APPRATUS REQUIRED
S.No Name of the apparatus Type Range Quantity
1
2
3
4
5
6
7
8
9
10
11
Ammeter
Ammeter
Ammeter
Voltmeter
Voltmeter
Voltmeter
Rheostat
Rheostat
Rheostat
Tachometer
Single Phase Variac
MC
MC
MI
MC
MC
MI
Wire wound
Wire wound
Loading
Digital
-
(0-15A)
(0-2A)
(0-10A)
(0-300V)
(0-50V)
(0-300V)
250, 2A
50, 5A
10A, 230V
-
230V / (0-270V)
1
1
1
1
1
1
1
1
1
1
7/27/2019 EC2259 LAB Manual
78/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
FORMULAE
1. Inertia Constant (J) ={{(Vav* Iav) / (Nav* N)}(60/2)2((t1*t2) /(t1-t2))} Kg-m
2
Where, Vav (V1+V2) / 2
Iav (I1+I2) / 2Nav(N1+N2) / 2
NSmall Change in Speed (i.e) N1~N2
t1Time for fall of speed from 1500 rpm to 750 rpm in no load conditionin seconds.
t2Time for fall of speed from 1500rpm to 750rpm in load condition inSeconds
2. Viscous Friction Co-Efficient (f) =(2/60)2(J /2) (N12~N22) in N-m / rad /Sec
Where, JInertia Constant in Kg-m2
Angular displacement in rad / Sec
= (2Nav/60)
3. Back EMF Constant (Kb) =(Va-IaRa) / (2N/60) in N-m / Amps
4. Torque T = (S1~S2) (R+ t/2) 9.81 in N-m.
Where, R- Radius of the Break drum in m.
t- Thickness of the Belt in m.
S1, S2- Spring balance reading in Kg.
5. Motor Gain Constant (Km) = KT/ (Raf)
Where KT= KT' (Current through the Armature / Rated Current of the Motor)
KT'= T/ Ia(From the Graphs)
6. Motor Time Constant (a) = La/ Ra.
Where, Xa=(Za2
-Ra
2
)
Xa= 2f La
La= Xa/ 2f
7. Transfer function Q(s) / E(s) =[KT/ (Raf)]
S{ [1+ (La/Ra) S] [1+ (J/f) S]+ [KTKb/(Raf)]}
7/27/2019 EC2259 LAB Manual
79/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
THEORY
Ra = Armature resistance in ohms.
La= Armature inductance of the winding in Henry.
Ia= Armature current in Amps.
If = Field current in Amps
E= Applied voltage in Volts.
Eb=Backemf in Volts.
Tm =Torque developed by the motor in N-m
=Angular displacement of motor shaft in radian.
J= Equivalent of moment of inertia of motor and load referred to motor shaft in kg-m2
f=Equivalent viscous friction coefficient of motor and load referred to motor shaft inN-m / rad / Sec.
Air gap flux is proportional to the field current because the DC motor should operatein linear magnetization curve for servo application.
(i.e) If KfIf Where, Kf is the Proportionality constant
The torque developed by the motor is proportional to the product of armature currentand air gap flux.
(i.e) Tm Ia
IaKfIf
= K1Ia KfIf
We know that Ifis constant for armature controlled motor.
(i.e) Tm = (K1 Kf If ) Ia
Tm= KT Ia Where, KTis themotor torque constant
Back emf of the emf of motor is proportional to the speed.
(i.e) Eb d ()/ dt
7/27/2019 EC2259 LAB Manual
80/82
EC2259 Electrical Engineering And Control System Lab Manual
Prepared by G.Panneerselvam, Vel Tech Multi Tech
Eb = Kb d ()/ dt -------------------------1Where, Kbis the back emf constant in volt / rad /sec
Loop equation of armature circuit
Va= Lad (Ia)/dt +RaIa+Eb ------------------ 2
Torque equation is
J d2/dt2 +f d/dt = Tm
=KTIa--------------3
Taking Laplace transform of Equations 1,2, & 3
From Eq (1) Eb(s) = KbS (s)------------ 4
From Eq (2) LaS Ia(s) +RaIa(s) = V(s) - Eb(s)
(LaS +Ra) Ia(s) = (V(s) - KbS (s))
Ia(s) = {(V(s) - KbS (s) / (LaS +Ra)}
From Eq (3) J S2 (s) +f S (s) = Tm(s)
(J S2 +f S) (s) = Tm(s) = KTIa(s)
(J S2 +f S) (s) = KTIa(s)
(J S2 +f S) (s) = KT{(E(s) - KbS (s) / (LaS +Ra)}
(JS2 +f S) (s) = KTE(s) - KTKbS (s)
(LaS +Ra) (LaS +Ra)
(JS2 +f S) (s) +KTKbS (s) = KTE(s)
(La S +Ra) (LaS +Ra)
7/27/2019 EC2259 LAB Manual
81/82
7/27/2019 EC2259 LAB Manual
82/82
EC2259 Electrical Engineering And Control System Lab Manua
To find out Torque Constant (KT)
1. Connections are given as per the circuit diagram.
2. The DC supply is given by closing the DPST switch.
3. The field current is kept constant.
4. The motor is made to run at the rated speed.
5. The various values of Iaspring balance readings are noted
6. Torque is calculated and plotted from the graph by adjusting the slope, torque constantKT is determined
To find out Back Emf Constant (Kb)
1.Connections are given as per the circuit diagram.
2. The motor is made to run at the rated speed.
3. At rated speed the supply voltage and armature value readings are noted.
4. The Back Emf constant is calculated.
To find out Armature resistance (Ra)
1. Connections are given as per the circuit diagram.
2. The DC supply is given by closing the DPST switch.
3. By adjusting the loading rheostat the various values of Ia and Va are noted.
4. The armature resistance is calculated by the application of formula.
To find out Armature inductance (La)
1. Connections are given as per the circuit diagram.
2. Using single phase variac the supply voltage is varied.
3. The corresponding reading of Ia are noted for different values of applied voltage
4. Then Za and La are calculated by using the formula.
Top Related