Control Sys Manual

7/30/2019 Control Sys Manual

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TRANSFER FUNCTION OF SEPARATELY EXCITED DC GENERATORUNDER LOAD CONDITION

Aim:To determine the transfer function of a separately excited dc generator under load

condition

Apparatus required:

Formulae:

Transfer function under loaded condition of a DC generator is

)1)(1()(

fa

t

sTsT

KsG

++

=

22

fff RZX =

f

XLf

f

2= f = 50Hz

22

aala RZX =

Sl Components Range Type Quantity

1 Ammeter (0-10A)(0-3A)

MCMC

11

2 Voltmeter (0-300V)(0-30V)

MCMC

11

3 Rheostat 150,5A

250

,1.5A

-

-

1

1

4 Auto Transformer - - 1

5 Tachometer - - 1


2/30

f

XL laa

2=

f

f

R

KK =

f

f

fR

LT =

)(

.

al

l

gRR

RKK

+

=

)(al

a

aRR

LT

+

=

gtKKK .=

f

gf

IEK

=

a

t

lI

VR

=

Precautions:

To find Rf and RL:

1. The dust switch should be kept open at the time of starting

2. The field rheostat should be kept at minimum resistance position.

3. The SPST switch should be kept open at the time of starting.4. Generator field rheostat should be at maximum resistance position

5. The loading rheostat should be in no load position

Procedure:

Determination of Rf and Kf:

1. Connections are given as per the circuit diagram.

2. Start the motor and adjust the field rheostat and make the motor to run atrated speed

3. Close SPST switch and adjust the generator field rheostat and note if

corresponding Eg and Ef values .

4. Reduce the If value and note down the corresponding Eg and Ef value andtabulate


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5. Calculate the value of Ra.

6. Draw the graph between If and Eg and find thevalue of Kf.

Determination of RL:

1. Connections are given as per the circuit diagram.2. Close the SPST switch.

3. Adjust the generator field rheostat and bring the voltmeter across the

generator armature to 220V.4. Close DPST switch2 vary the load and note down the corresponding Ia and

voltmeter Vt readings and tabulate it .

5. Draw the graph Ia Vs Vt and calculate RL.

To find Zf:


2. To certain point vary the autotransformer and note down correspondingvoltmeter and ammeter readings.

3. Calculate the value of Zfand find the mean of Zf.

To find Za:

1. Connections are given as per the circuit diagram

2. Vary the auto transformer and note the voltmeter and ammeter readings

3. Calculate the value of Za= Va/ Ia and find the mean value of zap

To Find Ra:

1. Connections are given as per the circuit diagrame

2. The resistive load should be in off position at the time of starting

3. Adjust the load and for each value of load note down the ammeter andvoltmeter readings.

4. Calculate the value of Ra = Va/ Ia and the mean

Tabulation:To determine Rf:


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Mean Rf =

To determine RL:

VT(volts)

IL(Amps)

RL(ohms)

To find Ra:

Mean Ra =

To find Za:

Sl. noIf in

Amps

Eg (volts) Ef (volts)Rf = Ef/If

Asc Des Mean Asc Des Mean

S.no Va(volts) Ia(amps) R a=Va/Ia


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Mean Za =

Name plate details:

DC Motor Generator

Fuse calculation:

S.no Va(volts) Ia(amps) Za=Va/Ia


6/30

Motor:

Generator:

Calculation:

Result:

TRANSFER FUNCTION OF SEPARATELY EXCITED DC GENERATOR ATNO LOAD CONDITION

Aim:To determine the transfer function of separately excited dc generator under no

load condition.

Apparatus required:


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Formulae:

Transfer function of separately excited DC generator at no load condition is given

by

f

fST

KT

+

=

1

f

g

R

KK =

f

f

fR

LT =

f

f

f

I

VR =

f

g

gI

EK

=

22

fff RZX =

f

XLf

f

2= f = 50Hz

Sl.No Components Range Type Quantity

1 Ammeter (0-2A)

(0-250 ma)

MC

MI

1

1

2 Voltmeter (0-300V)

(0-300V)

MC

MI

1

1

3 Rheostat500, 2A

250,1.5A-

1

2

4 Auto Transformer - - 1

5 Tachometer - - 1


8/30

Kg = generator constant in volts.

Tf= Time constant in seconds.

Xf = field constant of generator in ohms.

Precautions:

To Find Rf:

1. DPST switch is kept open at the time of starting

2. The field rheostat should be kept at minimum resistance position

3. The SPST switch must be kept open initially

4. The generator field rheostat should be kept at maximum resistanceposition

To find Zf:

1. The DPST should be kept open initially.2. The autotransformer should be kept at minimum resistance position.

Procedure:

To find Rf :


2. The supply is given by closing the DPST switch by using the starter and

by varying the field rheostat of the motor and made to run at rated speed.3. Corresponding readings of If, Eg and Vfare noted and tabulated.

4. The SPST switch is closed by adjusting generator field rheostat the Eg

readings are noted and tabulated.

5. Bring the motor field rheostat to minimum position and open the SPSTswitch and switch OFF the DC supply by opening the DPST.

To find Zf :


2. Varying the autotransformer If and Vf readings are noted.

Tabulation:


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To find Rf:

S.No If(Amps) Eg(volts) Ef(volts) Rf=Vf/If

Mean Rf =

To find Zf:

Mean Zf =

S.no

Vf(volts) If(amps) Zf=Vf/If


10/30

Name plate details:

Dc motor generator

Fuse calculation:

Motor:

Generator:

Calculations:

Result:


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STUDY OF THE RESPONSE OF PID CONTROLLER IN A PROCESS

Aim:To Study the Response of PID controller In a Process

Apparatus required:

Sl.no Components Quantity

1 Process control simulation 1

2 CRO 1

3 Patch chords -


12/30

Procedure:

1. Patch the front panel as shown in fig.

2. Set the process fast/ slow switch (SW4) and controller fast / slow switch

(SW3) in fast position.3. Apply a square wave of 2Vp. P at around 50 HZ.

4. Now patch I and adjust the integral time until steady state deviations.

5. Now note down the number of overshoots before the system settles.

6. Now connect D and slowly increase the deviation time and note down theeffect of this in system response.

Result:

STUDY OF STEPPER MOTOR

Aim:To study the operation of stepper motor controlled by a microprocessor unit

Apparatus required:

1. Microprocessor kit -1.

2. VBMB A13 -1.

3. Stepper motor.


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Program:

Start : LXI H, LOOKMVI B, OH

Rept: MOV A, M

OUT OC OHLXI D, 0303 H

Delay: NOPDLX DMOV A, E

ORA D

JNZ Delay

INX HDCR B

JMZ REPT

JMP START

Look up: DB 09 05 06 OA

Algorithm:

1. The HL register pair is initialized and loaded with appropriate data.

2. The count register B is loaded by 4.3. The data in HL register pair is outputted to pot.

4. The DE register pair is initialized with data.

5. A delay of 4 cycles is introduced through NOP instruction.

6. Delay function is continued until the DE register decrements to zero.7. The HL pair is incremented.

8. The count value is decremented.

9. If the count value is not zero the steps 3 to 7 is again repeated.10. If count becomes zero, then the above steps are again executed.

11. Thus, the stepper motor is interfaced with the 8085 microprocessor.

Result:

RESISTANCE TEMPERATURE DETECTING TRANSDUCER

Aim:To study the resistance Vs temperature characteristics, temperature Vs voltage

characteristics and the accuracy of RTD.

Apparatus required:

Sl No Components Quantity1. RJD module trainer 1


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2. Thermo meter 1

3. Multimeter 1

4. Patch chords Required nos

Precautions:

1. The water should be gradually heated.

2. The multimeter should be in range (0 - 200) to measure for (0 100C)

and for higher temperature s 700C, the range (0-500) may be preferred.

Procedure:

To study temperature Vs Resistance characteristics:

1. Ensure that the power to the unit is switched off.

2. Patch the three wires of the RTD to the plus (+), minus (-) and the ground

terminals placed in RTD i/p block.3. Place a multimeter in range (0-200) in resistance mode across the RTD.

4. Insert the RTD into the water bath and note down the resistance offered atroom temperature.

5. Heat the water and note the values of temperature and resistance.

6. Repeat steps for different values of temperatures and tabulate the readings.

7. Plot temperatures Vs resistance graph.

To study the Temperature Vs Voltage and accuracy of RTD:

1. Ensure the power to the unit is switched off.

2. Patch the three wires of the RTD to the plus (+), minus (- ) and the groundterminals placed in RTD i/p block.

3. Switch on the power supply to the unit.

4. Insert the RTD into the water bath and note the temperature without

heating at ambient condition.5. If there is any difference in temperature between that noted and of that

displayed in the front panel adjust the offset knob to vary the displayed

temperature to tally with the actual temperature else, this knob may be left

undisturbed.6. Now gradually start heating the water bath and note down the actual

temperature, o/p voltage of the unit and the displayed temperature

simultaneously7. Repeat steps 6 for different values of temperatures and tabulate the

readings.

8. Calculate the percentage error and plot the following graph(i) Temperature Vs voltage.

(ii) Temperature Vs % error.


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Theory:

Result:

STUDY OF THERMOCOUPLE TRANSDUCERAim:

To study the temperature characteristics of thermocouple.

Apparatus required:

Sl no Name of the components Quantity1 Thermocouple trainer 1

2 Thermometer 1

3 Multimeter 1

4 Patch chords 1


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Procedure:

1. Connect the two terminals of the thermocouple to the thermocouple trainer inputand ground point.

2. Conduct the voltmeter in my range

3. Measure the displayed voltage in the multimeter for room temperature4. Now insert the thermocouple into the water bath and start heating it gradually

5. Using a thermometer measure the temp and the corresponding thermocouple

output voltage.6. Repeat steps for different temperature of the water.

7. Tabulate the readings and plot the graph for temperature vs thermocouple.

Theory:

Calculation:

Result:

FREQUENCY OF LAG, LEAD, LAG LEAD NETWORKAim:

To determine the output response characteristics of lag, lead and lag-lead

network.

Apparatus required:

Sl no Name of the components Quantity1. CRO 1

2. Frequency generator 1


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3. Resister 2

4. Capacitor 2

5. Bread board 1

Procedure:

Lag network:

1. Connections are given as per the circuit diagram in the breadboard.

2. In lag network the capacitor is used in series with 1k resistor.

3. The voltage is set up to 15v.

4. Now, by varying the frequency in the frequency generator, correspondingamplitude is taken from the CRO.

5. Then waveforms are drawn for network and output lags behind input.

Lead network:

1. Connections are given as per the circuit diagram in the breadboard.

2. In the lead network capacitor is made parallel with 1k resister.

3. The maximum voltage is set up to 15v.

4. By varying the frequency corresponding amplitude is taken from CRO.

5. Then waveforms are drawn for the network and output leads the input.

Lag lead network:

1. Connections are given as per the circuit diagram.2. Two capacitors are used here where one capacitor is used in series with one

resistor and another is used in parallel with another resistor.

3. The maximum voltage is setup to 15v.4. By varying the frequency corresponding amplitude is taken from CRO.

5. Then waveforms are drawn for lag lead network.

Theory:

Result:TRANSFER FUNCTION OF AN AC SERVO MOTOR

Aim:To determine the transfer function of ac servo motor

Apparatus required:


18/30

1. Two phase ac servo motor speed control and transfer function study trainer (PEC

OOA).

2. Patch chords.

Formula:

1 . torque T=9.81* r *s

s-applied load in kg.

r radius of shaft in m2. transfer function = k1/SJ+K2+B.

3the values of J and B are given .

J= 0.052 kg/cm2

B=0.01875

Procedure:

To find k2:

1. Switch on the 230v ac supply to reference winding.2. Switch on the pulse ON/OFF switch S2.

3. By using control voltage pot (cv) , apply rated voltage to control phase winding.

4. Apply load on the motor step by step up to motor will run at o rpm.5. For each step note down the load speed and tabulate it.

6. Remove all the load and using control voltage pot (cv) apply th of the rated

voltage to control phase winding.

7. Apply load on the motor step by step up to motor will run at 0 rpm.8. For each step note down the load speed and tabulate it.

9. Find out the torque by using the formula given.

10. Plot the graph speed vs torque (for rated voltage and th of rated voltage).11. the slope of speed torque curve given the motor constant k2

To Find K1:

1. switch on the 230v ac supply to reference winding

2. switch on the pulse ON/OFF switch S23. apply rated voltage to control phase value using control voltage pot (c.v)4. apply load on the motor gradually till the motor will run in the o rpm.

5. note down voltmeter reading, load and tabulate it.

6. release the load on the motor slightly, the motor will run at certain rpm.7. release the control voltage slightly till the motor will run at 0 rpm.

8. note down the voltmeter reading, load and tabulate it.

9. repeat the same process again and again upto 0 load condition.10. apply rated voltage to control phase value using control voltage pot (cv).

11. apply load on the motor gradually till the motor will run in the th of rated rpm.

12. note down voltmeter readings , load and tabulate it.

13. release the load on the motor slightly the motor will run at certain rpm.


19/30

14. release the control voltage slightly till the motor will run at th of rated rpm.

15. note down the voltmeter readings , load and tabulate it.

16. repeat the same process again and again upto 0 load condition.17. plot the graph torque vs control voltage (for 0 rpm and th of rated rpm).

18. a slope of torque control voltage curve gives the motor constant k1.

THEORY:

CALCULATION

RESULT


20/30

Transfer function of dc shunt motor using ward Leonard system

Aim:

To determine the transfer function of dc shunt motor using ward Leonard system .

Apparatus required:

1. voltmeter

2. ammeter

3. autotransformer.4. rheostat.

Precautions:

1. before starting , dpst switch should be in open condtion .

2. autotransformer should be in minimum position before starting the experiment.3. motor 2 should be in no load condition.

4. generator field rheostat should be in maximum resistance position.Procedure:

To find kg and kf:

1. connections are given as per the circuit diagram.2. vary the transformer and make the 3phase induction motor to run at rated rpm.

3. close the dpst2 and now the motor 2 starts to rotate. Adjust the spring balance and

make the motor to stop.

4. note down the readings to generator field current and voltage , generator armaturecurrent, generator load current (or) motor load current, spring balance reading and

tabulate it.

5. close the spsts again the motor 2 starts to rotate and repeat step4.6. vary the generator field rheostat , again the motor 2 starts to rotate step4.

7. repeat step6 until the motor reaches the full load current.

To find kb:1. connections are given as per the circuit diagram.

2. vary the autotransformer and make the 3phase induction motor to run at rated

rpm.

3. close the dpst2 and make the motor to run. Note down the readings of the motorfield current ,speed, armature current,armaturevoltage and tabulate it.

4. close the spst switch and repeat step 3.

To find j :1. connections are given as per the circuit diagram.

2. before giving supply to motor supply rheostat should be kept in minimum resistance

position.3. the loading rheostat is adjusted to give 1 amp at rated voltage.

4. the supply voltage is given by closing the dpst switch on parallel position , then by

adjusting armature rheostat, motoris made to run at rated speed.

5. now, dpdt is open and time for fall of speed from rated to 500rpm below is noted in seconds.


21/30

6. now , initial adjustments are done using rheostat and dpdt is closed to parallel

position and motor is made to run at rated rpm. Now, switch is closed from

parallel11 to 22 position , time for fall in speed is noted at t2 sec , at the same time,voltmeter, ammeter readings are noted.

To find ra:

1. connections are given as per the circuit diagram.2. the resistive load should be in the off position at the time of starting.

3. adjust the load in steps for each value of load and note down the ammeter and

voltmeter readings and tabulate it.To find rf:

1. connections are given as per the circuit diagram.

2. the resistive load should be in off position at the time of starting .

3 adjust the load in steps and for each value of load , note down the ammeter,voltmeter readings and tabulate it.

To find zf:

1. connections are given as per the circuit diagram.

2.supply is given to by closing dust by varying theautotransformer correspondingvoltmeter and ammeter readings are noted in table.

Formula:

Calculation:

Result:


22/30

TRANSFER FUNCTION OF FIELD CONTROL OF DC SHUNT MOTORAim:

To obtain the transfer function of an armature controlled dc shunt motor.

Apparatus required:

Sl no Components Range Type Quantity

1 Voltmeter (0-300)V MC 1

(0-30)V MC 1

(0-300)V MI 1

2 Ammeter (0-3)A MC 1

(0-10)A MC 1

(0-10)A MI 1

3 Rheostat 150,5A - 1

400,1.5A - 1

4 Tachometer - - 1

Formulae:

Power developed,p1=

Mechanical power dissipated ,pm=

Precautions:

The DPST switch should be kept open at the time of starting.

The field rheostat should be kept at minimum position.

The armature rheostat should be kept at maximum position.

Procedure:


23/30

To find Kt:


2. The DPST is switched on.

3. Adjust the armature side rheostat and keep in fixed position so that the value of Iais maintained constant through the experiment.

4. Note down If ,Va ,Ia in table.

5. Adjust the field rheostat and note down the Va ,Ia,If and Speed.6. Graph is drawn between the torque and If.

Kt=T/If

To find Moment of Inertia (J):

1. Connections are made as per the circuit diagram

2. The DPST switch is switched ON. It is in the initial position at the time of

starting.3. After observing the precautions, switch on the DPST .

4. Adjust the field side rheostat and the armature side rheostat and allow the motorto run at rated speed N1.

5. Open the DPST and observe the speed of the motor .note the time taken for the

speed to fall down to any three values of the speed N2.6. Adjust the rheostat to initial position and switch of the DPST.

7. Open the DPST and bring 2-2 position and immediately note down the reading

8. Repeat the steps 2,3,4.

9. Observe that the speed falls rapidly for the same values of speed noted in stepsnote down the time taken, voltage and current.

10. Switch the dc supply.

To determine Ra:

1. Connections are made as per the circuit diagram2. The resistive should be in off position at the time of starting.

3. Adjust the load, for each values of load, note down the ammeter, voltmeter

readings.

To find Zf:

1. Connections are made as per the circuit diagram2. Vary the auto transformer and note down the corresponding ammeter and

voltmeter readings.

3. Calculate the value of Zf =Vf /If and find the mean of Zf.

To find Rf:


24/30

Precautions :

The DPST is kept open initially.

The field rheostat is kept at maximum position.

Procedure:

1. Connections are made as per the circuit diagram

2. For various values of rheostat, voltmeter and ammeter readings are noted..3. The field resistance is calculated by Rf= V/I.

Theory:

The speed of the dc motor is directly proportional to the armature voltage and

inversely proportional to the flux. In the field controlled dc motor, armature voltage iskept constant and the speed is varied by varying the flux of the machine.

Derivation of transfer function:Ef- field controlled voltage

Rf -field resistance

Lf-field inductanceTm-Torque developed by the motor

J- Moment of inertia of the motor.

F-Friction co efficient of the motor.

If-field current.

From the equivalent circuit the differential equation

The torque equation written as,

But Tm IaAssuming Ia is constant in the field controlled dc motor.

Tm

But If

Tm If

Tm = Kt + IfSubstitute eqn 3 in eqn 2, we get

Taking laplace transformation ,

L(s) = If(s) [Rf+ LfS]Kt I(s) = Q(s) [JS

2+FS]


25/30

Transfer function:

Calculation:

Result:

TRANSFER FUNCTION OF ARMATURE CONTROLLED DC SHUNT MOTOR

Aim:To obtain the transfer function of armature controlled dc shunt motor.


26/30

Apparatus required:

Sl

no

Components Range Type Quantity

1 Voltmeter 0-300)v

(0-30)V

MC

MC

1

1

2 Ammeter (0-10)A

(0-3)A

MC

MC

1

1

3 Rheostat 150,5a

350,1.5A

-1

4 Tachometer - - 1

Precautions:

The DPST switch must be kept open at the time of starting

The field rheostat should be kept at minimum resistance position

The motor should not be loaded at initial voltage.

The armature resistive load should be kept at maximum position

Formulae:

Procedure:

To find Kt:

1. Connections are made as per the circuit diagram.

2. Variable voltage through resistive load is given to the motor armature by closing

the DPST.

3. The motor starts to rotate then the load is applied so that the motor tends to stop.4. By increasing the armature current by varying load rheostat an armature side

again motor starts to rotate.

5. Above procedure is done up to rated current corresponding armature current andspring balance readings are noted.

To find J:


27/30

1. Connections are made as per the circuit diagram.

2. The DPST switch should be in 1-1 position at the time of starting.3. After observing the precautions, switch on the DPST.

4. Adjust the field side rheostat and armature side rheostat and allow the motor to

run at the rated speed.5. Open the DPST and observe the speed of the motor drops. Note down the time

taken for the speed to fall down to any three value of the speed.

6. Adjust the rheostat to initial position and switch off the DPST.7. Repeat the steps 2,3,4.

8. Open the DPST and bring 2-2 position and immediately note down the ammeter

and voltmeter readings.

9. Observe that the speed falls rapidly for the same value of the speed noted onsteps.

Theory:

Armature control method is used when speed below the no load speed arerequired. As the supplied voltage is normally constant ,the voltage across the armature is

varied by inserting a variable rheostat in series, with the armature circuit as shown .ascontrolled resistance is increased ,potential difference across armature is decreased. for

load of constant speed approximately proportional to the potential difference across the

armature.

Assumptions:

The field current is constant.The flux which is proportional to the field current is also constant.

The torque generated is proportional to the product of flux and the armature current

Tm Ia

T IaTm = KtIa

Where Kt is the motor constant

Back EMF of the motor is proportional to the speed and the flux

Eb .

Derivation of transfer function:

The equivalent circuit of armature can be given as follows:Ea armature control voltage

Ra armature resistance

La armature inductance

Eb Back emf.Ia - armature current.

From the equivalent circuit, differential equation

Taking laplace transformation on either side on Eqn 1, 3 and 4


28/30

Armature inductance is usually negligible and hence Eqn 8 can be written as

calculation:

Result:


29/30

M

230V DC

supply


30/30

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