EC2259 LAB Manual

7/27/2019 EC2259 LAB Manual

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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


2/82


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


3/82


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


4/82


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


5/82


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6/82


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


7/82


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


8/82


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


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


10/82


MODEL CALCULATION

RESULT

Thus the load test on DC shunt motor and its performance curves are drawn.


11/82


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


APPRATUS REQUIRED

S.NONAME OF THE


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.


12/82


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


13/82



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


14/82


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


APPRATUS REQUIRED

S.NONAME OF THE


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


15/82


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


16/82


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.


17/82


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


18/82


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


19/82


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


APPRATUS REQUIRED

S.NONAME OF THE


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.


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


21/82



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


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


22/82



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)


23/82



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


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.


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


25/82



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


26/82



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)


27/82



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


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


28/82


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


29/82



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


30/82


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


31/82



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


32/82



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


33/82


Prepared by G.Panne

CIRCUIT DIAGRAM FOR OPEN CIRCUIT TEST ON SINGLE PHASE TRA


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


34/82


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


N

P

Fuse

B

SPSTS

P1

P2

(0-5A)MI

1 230/11STEP

TRANSF

41


35/82



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

=


36/82



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


37/82



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


Output power Vs Efficiency Output power Vs Regulation

Output power

(Output power +Total Losses)

X Isc [R02 x cos X02 x sin]V2o


38/82


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


39/82


40/82



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


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.


41/82


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


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


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.


43/82


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


44/82



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


45/82



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


46/82


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


47/82


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


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


49/82



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


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.


50/82



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


51/82



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


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


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


53/82



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)


54/82



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


55/82



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


56/82



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+


57/82



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


58/82



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


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.


59/82


60/82



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.


61/82



DIGITAL SIMULATION OF LINEAR SYSTEM

AIM

To simulate the time response characteristics of second order linear system using

MATLAB.

APPRATUS REQUIRED


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.


62/82



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).


63/82



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.


64/82



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.


65/82


Type 0 First Order System with P Controller

Computer CH 0 Computer CH 1

Step Input

(FG)

P Controller

Level ShifterLevel Shifter


66/82


Type 0 First Order System with PI - Controller


Step Input

(FG)

PI Controller



67/82


Type 0 First Order System with PID - Controller


Step Input

(FG)

PID Controller



68/82



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


2. Set Proportional Band = 80, Integral Time = 30 and Derivative Time = 0.


Type 0 First Order System with PI Controller


2. Set Proportional Band = 80, Integral Time = 30 and Derivative Time = 0.1.


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


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Model Graph

RESULT

Thus the design of P, PI and PID controller was done.


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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


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Type II Order System Performance

Without Lag Compensator


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




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


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Type II Order System Performance

Without Lead Compensator




4. Set Pb = 100%.

5. Measure the time domain specification of the I order system from the waveform.

With Lead Compensator




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


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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.


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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


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


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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)


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PROCEDURE

To find out Generated EMF Constant (Kg)


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)


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.


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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:


APPRATUS REQUIRED


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


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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)]}


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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


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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)


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To find out Torque Constant (KT)


2. The DC supply is given by closing the DPST switch.

3. The field current is kept constant.


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.


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)


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)


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.

EC2259 LAB Manual

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Transcript of EC2259 LAB Manual