Power Electronics Lab Manual ME PED

Power Electronics and Drives Lab Manual

Muthayammal Engineering college, Rasipuram.

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MUTHAYAMMAL ENGINEERING COLLEGE, RASIPURAM Department of Electrical and Electronics Engineering

MUTHAYAMMAL EDUCATIONAL INSTITUTIONS

D E S I G N I N G YOUR F U T U R E

II Semester – ME (PED)

PE 1655 - Power Electronics and Drives Laboratory

Manual Prepared by Approved by Prof.M.Muruganandam, M.E., Dr P.Murugesan,B.E.,Ph.D., AP/ EEE MISTE, MIIPE, MIETE, FUWAI Proff. & HOD/EEE Revision No.:0 Date:01.01.2007



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INSTRUCTIONS TO THE CANDIDATE

SAFETY: You are doing experiments in Power Electronics lab with high voltage and

high current electric power. It may cause even a fatal or loss of energy of your body system. To avoid this please keep in mind the followings

In case of any wrong observations, you have to SWITCH OFF the power supply related with it.

You have to tuck in your shirts or wear an overcoat. You have to wear shoes compulsorily and stand on mats made by

insulating materials to electrically isolate your body from the earth. ATTENDANCE:

If you absent for a lab class then you have lost several things to learn. Laboratory should be treated as temple, which will decide your life. So don’t fail to make your presence with your record notebook having completed experiments, observation with completed experiments, day’s experiment particulars with required knowledge about it and stationeries. MAKING CONNECTIONS:

Get circuit diagram approval from your staff in charge. Go to the respective worktable and start to give connection as per the

circuit diagram from source side. Make series circuit connections before the parallel circuits like voltmeter

connections. Before switch on the power, get circuit connection approval from the staff

in charge. DOING EXPERIMENT:

Start the experiment in the presence of an instructor / staff in-charge and do the same by proper procedure.

If staff permits you then precede your experiment. OBSERVATION:

Before take the wave forms calibrate the CRO. Note all the required readings in their respective tables. Note all the wave forms from the CRO.

CALCULATION: Calculate the required quantities by suitable formulae and tabulate them

with units. Draw the necessary graphs and write the result with reference. Get verification of observation and calculation from your staff in charge.



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RECORD: Record is show the equipment’s and your performance. It will be very

useful for future reference. So keep it as follows. Enter the things in the record notebook those have been written in your

observation. Units should be written for all quantities. Draw necessary graphs and complete the record before coming to the

next lab class. Don’t forget to write the theory with precaution and inference of each

experiment.

MAY I HELP YOU

1. Device ratings should be noted. 2. Moving coil meters should be used for DC measurements. 3. Moving iron meters should be used for AC measurements. 4. Use isolated supply for the CRO. 5. Use attenuation probe for high voltage measurements in CRO.



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CONTENTS

Sl.No. Name of the experiment Page No.

1. Single Phase Semi-converter with R-L and R-L-E loads for continuous and discontinuous conduction modes.

02

2. Single phase full- converter with R-L and R-L-E loads for continuous and discontinuous conduction modes.

08

3. Three phase full-converter with R-L-E load. 14

4. MOSFET based step up and step down chopper. 20

5. IGBT based Single phase PWM inverter. 28

6. Single phase AC voltage controller using SCR and using TRIAC. 34

7. IGBT based four quadrant choppers.

8. IGBT based Three phase inverters.

9. Simulation of closed loop control of converter fed DC motor drive.

10. Simulation of closed loop control of chopper fed DC motor drive.

11. Simulation of VSI fed three phase induction motor drive.

12. Simulation of three phase synchronous motor and drive.



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SINGLE PHASE SEMI-CONVERTER WITH R-L AND R-L-E LOADS FOR CONTINUOUS AND DISCONTINUOUS CONDUCTION MODES

CIRCUIT DIAGRAM FOR R-L LOAD

Model graph for R-L Load with continuous conduction (αααα = 30°°°°, R=100ΩΩΩΩ, L=100mH)

Model graph for R-L Load with discontinuous conduction (αααα = 90°°°°, R=100ΩΩΩΩ, L=100mH)



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SINGLE PHASE SEMI-CONVERTER WITH R-L AND R-L-E LOADS FOR CONTINUOUS AND DISCONTINUOUS CONDUCTION MODES

AIM:

To study the wave form for single phase full wave half controlled bridge rectifier with R-L and R-L-E loads for continuous and discontinuous conduction modes. APPARATUS REQUIRED: S.No. Name of the item Type Range Quantity

1 SCR module with protection TYN612 600V,12A 2 2 Diode module with protection BY126 - 3 3 SCR Triggering Kit - - 1 4 Battery - 12V 1 5 Ammeter MC (0-500) mA 1 6 Voltmeter MC (0-30) V 1 7 CRO - - 1 8 CRO Brobe - - 1 9 Patch Cards - - 10

FORMULA USED:

For RL load continuous & discontinuous conduction and for RLE load continuous conduction: 1. Average dc output voltage Vdc is )cos1( απ += m

dcVV

2. RMS output voltage is Vrms 21

22sin

21

+−= ααππmrms VV

For RLE load discontinuous conduction: 3. Average dc output voltage Vdc is

−++= π

γαπ 1)cos1( EVV mdc

4. RMS output voltage ( )21

22

22sin

21

−++

+−= βαπααππ EVV mrms



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CIRCUIT DIAGRAM FOR R-L-E LOAD

Model graph for R-L-E Load with continuous conduction (αααα = 30°°°°, R=100ΩΩΩΩ, L=200mH, E=30V)

Model graph for R-L-E Load with discontinuous conduction (αααα = 90°°°°, R=100ΩΩΩΩ, L=200mH, E=30V)



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General Formula: 5. Rectification efficiency 2

2%

rms

dcVV

=η

6. Form factor dc

rmsVVFF =

7. Peak inverse voltage mVPIV = 8. Ripple factor 12 −= FFRF

Where mV = maximum or peak voltage in volts = sV2 sV = Supply voltage in volts

α = Firing angle β = Extinction angle γ = Conduction angle = β -α

Procedure:

1. Connections are made as per the circuit diagram for RL load 2. Switch on the triggering kit 3. Switch on the 24V AC supply 4. Switch on the debounce logic 5. By varying potentiometer vary the firing angle of the converter in order to vary the

output voltage step by step. 6. For each step note down the firing angle, output voltage and load current. 7. The output voltage is theoretically calculated for each step and the readings are

tabulated. 8. Repeat the same procedure for RLE load.



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Tabulation for RL load:

Vs= R= L= S.No. Firing Angle

αααα in degree Idc Measured in milliamps

Vdc Measured in volts

Vdc Calculated in volts

Vrms Calculated in volts

Continuous conduction

Discontinuous conduction

Tabulation for RLE load:

Vs= R= L= E= ββββ =

S.No. Firing Angle αααα in degree

Idc Measured in milliamps








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INFERENCE: DISCUSSION QUESTIONS: 1. What is power electronics? 2. What are the types of converter in power electronics? 3. What is firing angle? 4. What is active load? 5. Why the negative voltage is not possible in semi converter? 6. What is freewheeling diode? 7. Is a separate freewheeling diode necessary for semi converter? Justify your answer. RESULT:



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SINGLE PHASE FULL-CONVERTER WITH R-L AND R-L-E LOADS FOR CONTINUOUS AND DISCONTINUOUS CONDUCTION MODES

CIRCUIT DIAGRAM FOR R-L LOAD

Model graph for R-L Load with continuous conduction (αααα = 30°°°°, R=100ΩΩΩΩ, L=200mH)

Model graph for R-L Load with discontinuous conduction

(αααα = 90°°°°, R=100ΩΩΩΩ, L=200mH)



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SINGLE PHASE FULL-CONVERTER WITH R-L AND R-L-E LOADS FOR CONTINUOUS AND DISCONTINUOUS CONDUCTION MODES

AIM:

To study the wave form for single phase fully controlled bridge rectifier with R-L and R-L-E loads for continuous and discontinuous conduction modes. APPARATUS REQUIRED: S.No. Name of the item Type Range Quantity

1 SCR module with protection TYN612 600V,12A 4 2 SCR Triggering Kit - - 1 3 Battery - 12V 1 4 Ammeter MC (0-500) mA 1 5 Voltmeter MC (0-30) V 1 6 CRO - - 1 7 CRO Brobe - - 1 8 Patch Cards - - 10

FORMULA USED:

For RL load continuous and for RLE load continuous conduction: 1. Average dc output voltage Vdc is απ cos2 m

dcVV =

2. RMS output voltage Vrms is sm

rms VVV == 2

For RL load discontinuous conduction: 3. Average dc output voltage Vdc is )cos(cos βαπ −= m

dcVV

4. RMS output voltage Vrms is 21

2

22sin

22sin

2

+−−= αβαβπm

rmsVV

For RLE load discontinuous conduction:

5. Average dc output voltage Vdc is ( ( ))βαπβαπ −++−= EVV mdc )cos(cos1

6. RMS output voltage ( )21

22

22sin

22sin

21

−++

+−−= βαπαβαβπ EVV mrms



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Model graph for R-L-E Load with continuous conduction

(αααα = 30°°°°, R=100ΩΩΩΩ, L=300mH, E=30V)

Model graph for R-L-E Load with discontinuous conduction

(αααα = 90°°°°, R=100ΩΩΩΩ, L=300mH, E=30V)



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2%

rms

dcVV

=η

8. Form factor dc

rmsVVFF =

9. Peak inverse voltage mVPIV = 10. Ripple factor 12 −= FFRF

Where mV = maximum or peak voltage in volts = sV2 sV = Supply voltage in volts


Procedure:


output voltage step by step. 6. For each step note down the firing angle, output voltage and load current. 7. The output voltage is theoretically calculated for each steps and the readings are




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Tabulation for RL load: Vs= R= L= ββββ=

S.No. Firing Angle

αααα in degree Idc Measured in milliamps







Vs= R= L= E= ββββ=










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INFERENCE: DISCUSSION QUESTIONS:

1. What is inversion mode of operation? 2. When we connect a freewheeling diode in full converter what will be the output? 3. Why the inversion mode is not possible in semi converter? 4. Why the power factor of full converter is lower than semi converter? 5. What isα,β,γ and µ?

RESULT:



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THREE PHASE FULL-CONVERTER WITH R-L-E LOAD FOR CONTINUOUS AND DISCONTINUOUS CONDUCTION MODES


Model graph for R-L-E Load with continuous conduction (αααα = 30°°°°, R=100ΩΩΩΩ, L=1000mH, E=50V)



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THREE PHASE FULL-CONVERTER WITH R-L-E LOAD FOR CONTINUOUS AND DISCONTINUOUS CONDUCTION MODES

AIM:

To study the wave form for three phase full-converter with r-l-e load for continuous and discontinuous conduction modes APPARATUS REQUIRED: S.No. Name of the item Type Range Quantity

1 3ϕ SCR module with protection TYN612 600V,12A 4 2 3ϕ Triggering Kit - - 1 3 DC motor Sep. Excited 1 KW 1 4 Ammeter MC (0-5) A 1 5 Voltmeter MC (0-600) V 1 6 CRO - - 1 7 CRO Brobe - - 1 8 Patch Cards - - 10

FORMULA USED:

For RLE load continuous conduction: 1. Average dc output voltage Vdc is απ cos33 m

dcVV =

2. RMS output voltage Vrms is 21

2cos433

213

+= απmrms VV

For RLE load discontinuous conduction:

3. Average dc output voltage Vdc is 4. RMS output voltage



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Model graph for R-L-E Load with discontinuous conduction (αααα = 80°°°°, R=100ΩΩΩΩ, L=100mH, E=50V)



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2%

rms

dcVV

=η

6. Form factor dc

rmsVVFF =

7. Peak inverse voltage mVPIV 3= 8. Ripple factor 12 −= FFRF

Where mV = maximum or peak phase voltage in volts = sV2 sV = Supply phase voltage in volts


Procedure:


output voltage step by step. 6. For each step note down the firing angle, output voltage and load current. 7. The output voltage is theoretically calculated for each steps and the readings are




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Vs= R= L= E= ββββ=










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1. Why we go for three phase converter? 2. What are the applications of three phase full converter? 3. What are the methods to reduce the ripple content? 4. Explain about the commutation? 5. What are the differences between converter grade SCR and inverter grade SCR?

RESULT:



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MOSFET BASED STEP UP AND STEP DOWN CHOPPER

CIRCUIT DIAGRAM FOR STEP DOWN OPERATION

Model graph for step down operation



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MOSFET BASED STEP UP AND STEP DOWN CHOPPER AIM:

To study the wave form for MOSFET based step down chopper, step up chopper and step up & step down chopper for different load for continuous and discontinuous conduction modes. APPARATUS REQUIRED: S.No. Name of the item Type Range Quantity

1 MOSFET Module IRF 840 - 1 2 Ammeter MC (0-500mA) 1 3 Voltmeter MC (0-30V) 1 4 Rheostat - - 1 5 RPS - (0-30V) 1 6 Diode Py 127 - 1 7 Inductor Ferrite core 100mH 1 8 CRO - - 1 9 CRO Probe - - 1

10 Patch cards - - - FORMULA USED:

For step down chopper 1. Average dc output voltage Vdc is sdc VV δ= 2. RMS output voltage Vrms is srms VV δ= For step up chopper 3. Average dc output voltage Vdc is ( )δ−= 1

sdc

VV

For step up and step down chopper 4. Average dc output voltage Vdc is ( )δ

δ−= 1s

dcVV

Where δ = Duty cycle of the chopper T

TON=δ TON = on time T = Total time



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CIRCUIT DIAGRAM FOR STEP UP OPERATION

Model graph for step up operation



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Procedure:

1. Connections are made as per the circuit diagram for step down chopper 2. Switch on the RPS first and turn on triggering kit 3. Switch on the debounce logic 4. By changing the width of the pulse, obtain the different set of reading. 5. For each step note down the duty cycle, output voltage and load current. 6. The output voltage is theoretically calculated for each step and the readings are

tabulated. 7. Repeat the same procedure for step up chopper and step up& step down

chopper. 8. Draw the graph as per the reading in the table.



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CIRCUIT DIAGRAM FOR STEP UP AND STEPDOWN OPERATION

Model graph for step down operation



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1. What is chopper and what are the devices generally used for chopper? 2. What are the types of chopper? 3. What are the control strategies used for choppers? 4. Why frequency modulation is not preferred mostly? 5. Why thyristor is not preferred in chopper circuit mostly?



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Tabulation for step down chopper: Vs= T=

S.No. TON in ms δδδδ = T

TON Idc (Avg) Measured

in mA

Vdc (Avg) Measured

in volts

Vdc (Avg) Calculated

in volts sdc VV δ=

1 2 3 4 5

Tabulation for step up chopper: Vs= T= S.No. TON

in ms δδδδ = TTON Idc (Avg)

Measured in mA

Vdc (Avg) Measured

in volts


in volts

( )δ−= 1s

dcVV

1 2 3 4 5

Tabulation for step down & step up chopper: Vs= T= S.No. TON

in ms δδδδ = TTON Idc (Avg)

Measured in mA

Vdc (Avg) Measured

in volts


in volts

( )δδ−= 1s

dcVV

1 2 3 4 5



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RESULT:



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IGBT BASED SINGLE PHASE PWM INVERTER

CIRCUIT DIAGRAM



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IGBT BASED SINGLE PHASE PWM INVERTER AIM:

To study the wave form for single phase bridge inverter with R load APPARATUS REQUIRED: S.No. Name of the item Type Range Quantity

1 IGBT Module - - 1 2 Inverter control module - - 1 3 CRO - - 1 4 Ammeter MI (0-5A) 1 5 Voltmeter MI (0-300V) 1 6 Patch cards - - -

FORMULA USED:

1. Modulation index (m) is m = Ar / Ac 2. Output voltage V0 = m Vs

Where

Ar = Amplitude of reference signal Ac = Amplitude of carrier signal Vs = Source voltage



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Model graph

Sinusoidal Pulse width modulation

Voltage and current waveforms



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Precaution:

1. Check whether AC main switch is off condition in both the trainer. 2. Check whether control module mode selector switch is in first position (Sine

wave). 3. Check whether control module pulse release switch SW4 in control module is off

position. 4. Check whether 24V AC switch is in off position.

Procedure: 1. Make the connection as per the circuit diagram. 2. Switch on the AC main in both the trainer. 3. Measure the amplitude and frequency of sine wave and carrier triangular wave

and tabulate it. Also adjust sine wave frequency to 50Hz. 4. Connect CRO probe to observe the load voltage and load current waveform. 5. Release the switch SW4 in the inverter control module and switch SW1 in the

IGBT power module. 6. Measure the output voltage. 7. Using the amplitude POT to vary step by step, for each step note down the

amplitude and frequency of sine wave and triangular waveform and also measure the output voltage and tabulate it.

8. Then find the theoretical output voltage by using the formula.



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Tabulation:

Vs=

S.No. Amplitude of carrier

triangular wave (Ac) in volts

Amplitude of reference sine wave

(Ar) in volts

Modulation index

m= Ar/Ac

I0 Measured in Amps

V0 Measured in Volts

V0 Calculated

in Volts V0 = m X

Vs 1 2 3 4 5 6



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1. What is inverter? 2. Why we go for PWM? 3. What are the different types of PWM? 4. What is modulation index and what are the types? 5. What are the advantages of IGBT?

RESULT:



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SINGLE PHASE AC VOLTAGE CONTROLLER USING SCR AND USING TRIAC

CIRCUIT DIAGRAM USING TRIAC

CIRCUIT DIAGRAM USING SCR



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SINGLE PHASE AC VOLTAGE CONTROLLER USING SCR AND USING TRIAC AIM:

To study the wave form for single phase ac voltage controller using SCR and Triac.

APPARATUS REQUIRED: S.No. Name of the item Type Range Quantity

1 Triac Module - BTA12 1 2 SCR module - - 1 3 CRO - - 1 4 Ammeter MI (0-5A) 1 5 Voltmeter MI (0-300V) 1 6 Patch cards - - - 7 Transformer - (0-12V) 1

FORMULA USED:

1. The RMS output voltage is 21

0 221

+−= ααππ

SinVV sRMS Where

α = Firing angle Vs = Source voltage



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Model graph For αααα = 60°°°°

Tabulation:

Vs=

S.No. Firing angle (αααα) in degree

I0RMS Measured in Amps

V0RMS Measured in Volts

V0RMS Calculated in Volts

1 2 3 4 5 6



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Procedure: 1. Make the connection as per the circuit diagram. 2. Switch on the AC main in the triac module. 3. Connect CRO probe to observe the load voltage waveform. 4. Measure the output voltage and current. 5. Using the firing angle POT to vary step by step, for each step note down the

waveform and also measure the output voltage and tabulate it. 6. Then find the theoretical output voltage by using the formula. 7. Repeat the same using SCR module. 8. Draw the wave forms.


1. What is voltage controller? 2. What are the different types of voltage controller? 3. In inductive load when the overlap angle is more than π+α then what will be the

output? 4. What are the advantages and applications of voltage controller? 5. What type of commutation is preferred?

RESULT:

Education

Power Electronics Lab Manual ME PED