Muthayammal Power

EE1303-Power Electronics Lab Manual

Muthayammal Engineering college, Rasipuram.

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MUTHAYAMMAL ENGINEERING COLLEGE, RASIPURAM Department of Electrical and Electronics Engineering

V Semester – BE (EEE)

EE 1303 - Power Electronics Laboratory

Manual Prepared by Approved by Prof.M.Muruganandam, M.E.,(Ph.D), Dr P.Murugesan,B.E.,Ph.D., AP/ EEE Proff. & HOD/EEE Revision No.:1 Date:24.06.2008



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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.

RECORD:



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Shows the performance of equipment and yourself. It will be very useful for future reference. So keep it as follows.

Write neatly; as they have to be preserved enter the readings 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. VI CHARACTERISTICS OF SCR 2

2. VI CHARACTERISTICS OF TRIAC 8

3. VI CHARACTERISTICS OF MOSFET

14

4. VI CHARACTERISTICS OF IGBT

20

5. TRANSIENT CHARACTERISTICS OF MOSFET AND SCR

24

6. SINGLE PHASE AC TO DC FULLY CONTROLLED CONVERTER

30

7. SINGLE PHASE AC TO DC HALF CONTROLLED CONVERTER

36

8. STEP DOWN MOSFET BASED CHOPPER

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9. STEP UP MOSFET BASED CHOPPER

46

10. IGBT BASED SINGLE PHASE PWM INVERTER 50

11. SERIES RESONANT DC-DC CONVERTER (ZERO CURRENT SWITCHING)

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12. PARALLEL RESONANT DC-DC CONVERTER (ZERO VOLTAGE SWITCHING)

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VI CHARACTERISTICS OF SCR

CIRCUIT DIAGRAM:

VI Characteristics

1ϕϕϕϕ Half wave Rectifier

Triggering Circuit for 1ϕϕϕϕ Half wave Rectifier



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AIM: (i) To Conduct an experiment and obtain the anode forward conduction

characteristics of the given SCR also find the latching and holding currents of the given SCR.

(ii) To Demonstrate how a single-phase half wave rectifier circuit can be implemented using a given SCR, AC power source and RC firing circuit.

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

1 SCR module TYN612 600V,12A 1 2 Ammeter MC (0-100) mA 1 3 Ammeter MC (0-50) mA 1 4 Voltmeter MC (0-30) V 1 5 Digital Multimeter - - 1 6 RC Firing Module - - 1 7 Rheostat - 220Ω 1 8 CRO - - 1 9 CRO probe - - 1

10 Patch Cards - - 10 FORMULA USED:

1. Average dc output voltage Vdc is )cos1( απ += mdc

VV

2. RMS output voltage is Vrms 21

22sin1

2

+−= ααππm

rmsVV

3. Rectification efficiency 2

2%

rms

dcVV

=η

4. Form factor dc

rmsVVFF =

5. Peak inverse voltage mVPIV = 6. Ripple factor 12 −= FFRF

7. Power factor 21

22sin

21

+−= ααππPF 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



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MODEL GRAPH:


1ϕϕϕϕ HALF WAVE RECTIFIER



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PRECAUTION:

1. The initial set gate current should be taken as minimum in order to take the consecutive readings.

2. Maximum anode current, anode-cathode voltage and gate current limit is 600mA,

30V and 20mA respectively

3. Before setting each gate current, keep the Anode to cathode voltage (VAK) as zero.

PROCEDURE: VI Characteristics:

1. Connections are made as per the circuit diagram. 2. Switch on the 230V AC supply through three-pin power chord. 3. Keep the gate current (IG) to a suitable value (say minimum of 4 mA to 5mA) 4. Now slowly increase the anode-cathode voltage (VAK) by varying the pot till

thyristor get turned on, with the indication that anode cathode voltage decreases to it on state voltage drop (i.e 0.7V) and the anode current increases.

5. Note the values of voltmeter (VAK) which is the break over voltage and the ammeter (I L) which is the latching current value.

6. Further, increase the anode current in steps by varying the anode-cathode voltage and note the readings.

7. Now reduces the anode cathode voltage (VAK) till the thyristor turned off and find the holding current.

8. For various gate current take the readings and tabulate it. 9. Finally, a graph of anode current Vs anode-cathode voltage is plotted for various

gate current.



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TABULATION: VI Characteristics:

S.No. IG1 = IG2 = IG3 = VAK(V) IA(mA) VAK(V) IA(mA) VAK(V) IA(mA)

1 2 3 4 5 6

1ϕϕϕϕ HALF WAVE RECTIFIER:

S.NO. Firing angle αααα°°°°

Practical Vavg (V)

Practical Iavg (A)

Theoretical Vavg (V)

Theoretical Vrms

1 2 3 4 5 6



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1ϕϕϕϕ HALF WAVE RECTIFIER:

1. Connections are made as per the circuit diagram. 2. Switch on the triggering circuit 3. Switch on the 24V AC supply 4. By varying potentiometer, vary the firing angle of the converter in order to vary

the output voltage step by step. 5. For each step note down the firing angle, output voltage and load current. 6. The output voltage is theoretically calculated for each step and the readings are

tabulated. INFERENCE: DISCUSSION QUESTIONS: 1. What is power electronics? 2. What are the types of converter in power electronics? 3. What is latching and holding current? 4. What is break over voltage? 5. What is forward bias and reverse bias? 6. What is firing angle? 7. Why the negative voltage is not possible in semi converter? 8. What is freewheeling diode? RESULT:



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VI CHARACTERISTICS OF TRIAC

CIRCUIT DIAGRAM:

VI Characteristics

Single-phase A.C phase controller for illumination control



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AIM:

(i) To obtain the forward and reverse conduction characteristics of the given TRIAC also find the latching and holding currents of the given TRIAC.

(ii) To demonstrate how a single- phase AC phase controller can be implemented for controlling the illumination of lamp, using given TRIAC and RC triggering circuit and draw the voltage wave form across the lamp.


1 TRIAC module BTA 12 600V,12A 1 2 Ammeter MC (0-100) mA 1 3 Ammeter MC (0-50) mA 1 4 Voltmeter MC (0-30) V 1 5 Voltmeter MI (0-300)V 1 6 Ammeter MI (0-500)mA 1 7 Digital Multimeter - - 1 8 Transformer - 230/12V 1 9 CRO - - 1

10 CRO Probe - - 1 11 Patch Cards - - 10

FORMULA USED:

The RMS output voltage is 21

0 221

+−= ααππ

SinVV sRMS Where

α = Firing angle Vs = Source voltage

PRECAUTION:

1. The initial set gate current should be taken as the value, for gate current for the consecutive readings.

2. Maximum triac current, voltage across the triac and gate current limit is 600mA,

30V and 20mA respectively.

3. To see the phase controlled converter output waveform, use a 230 / 12 V transformer for isolation purpose.



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MODEL GRAPH:


Single-phase A.C phase controller for illumination control



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PROCEDURE: VI Characteristics:

1. Connections are made as per the circuit diagram with MT1 +Ve with respect to MT2.

2. Switch on the 230V AC supply through three-pin power chord. 3. Keep the gate current (IG) to a suitable value (say minimum of 4 mA to 5mA) 4. Now slowly increase the anode-cathode voltage (VAK) by varying the pot till Triac

get turned on, with the indication that anode cathode voltage decreases to it’s on state voltage drop (i.e 0.7V) and the anode current increases.

5. Note the values of voltmeter (VAK) which is the break over voltage and the ammeter (I L) which is the latching current value.

6. Further, increase the anode current in steps by varying the anode-cathode voltage and note the readings.

7. Now reduces the anode cathode voltage (VAK) till the triac turned off and find the holding current.

8. For various gate current take the readings and tabulate it. 9. Connect MT2 terminal of Triac is + Ve with respect to MT1 10. Repeat the same procedure from 2 to 8 11. Finally, a graph of anode current Vs anode-cathode voltage is plotted for various

gate current for forward and reverse biases. Single-phase A.C phase controller for illumination control

1. Connections are made as per the circuit diagram. 2. Switch on the 230 V, 50 Hz AC supply 3. By varying potentiometer, vary the firing angle of the converter in order to vary

the output voltage there by the illumination of the lamp will be varied. 4. For each step note down the firing angle, ammeter reading, voltmeter reading

and the output voltage waveform from and tabulate it. 5. Finally, the output voltage waveform is plotted and the theoretical RMS voltage is

calculated.



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TABULATION: VI Characteristics: MT1 is + Ve with respect to MT2


1 2 3 4 5

MT2 is + Ve with respect to MT1


1 2 3 4 5

Single-phase A.C phase controller S.No. Firing angle (αααα) in

degree I0RMS Measured

in Amps V0RMS Measured

in Volts V0RMS Calculated

in Volts 1 2 3 4 5



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INFERENCE: DISCUSSION QUESTIONS: 1. What is bidirectional device? 2. What is bipolar device? 3. What are the applications of phase controlled converter in home appliances? 4. What is the number and range of given triac? 5. What type of firing is used here? 6. How do you change the firing angle? 7. Draw the symbol of Triac. RESULT:



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VI CHARACTERISTICS OF MOSFET

CIRCUIT DIAGRAM:

VI CHARACTERISTICS



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VI CHARACTERISTICS OF MOSFET

AIM: (i) Obtain the steady – state output – side characteristics and transfer

characteristics of the given MOSFET, for a specified value of gate – source voltage.

(ii) Identify whether given switch is MOSFET or IGBT by finding the

output– side characteristics.


1 MOSFET module IRF 840 600V,5A 1 2 Ammeter MC (0-100) mA 1 3 Voltmeter MC (0-10)V 1 4 Voltmeter MC (0-30) V 1 5 CRO - - 1 6 CRO Probe - - 1 7 Patch Cards - - 10

FORMULA USED: 1. Trans conductance

DS

Dm V

IG ∆∆

= mho

2. Output resistance D

DSDS I

VR ∆∆

= ohm Where: ∆ID = Change in drain current. ∆VDS = Change in drain to source voltage PRECAUTION:

The initial set gate voltage should be taken as minimum in order to take the consecutive readings.

PROCEDURE: DRAIN CHARACTERISTICS

1. Connections are made as per the circuit diagram 2. Switch on the 230V AC supply through three-pin power chord.



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MODEL GRAPH: DRAIN CHARACTERISTICS

TRANSFER CHARACTERISTICS



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3. Keep the gate - source voltage (VGS) to a suitable value (say minimum of 6V to 7V)

4. Now slowly increase the drain-source voltage (VDS) by varying the pot till MOSFET get turned on, with the indication that drain-source voltage decreases to it on state voltage drop.

5. Note down the values of drain-source voltage (VDS) and the drain current (I D) 6. For various gate-source voltage take the different set of readings and tabulate it. 7. Finally, a graph of drain-source voltage (VDS) Vs drain current (ID) is plotted for

various gate-source voltage. TRANSFER CHARACTERISTICS

1. Connections are made as per the circuit diagram 2. Switch on the 230V AC supply through three-pin power chord. 3. Keep the Drain - source voltage (VDS) to a suitable value 4. Now slowly increase the gate - source voltage (VGS) by varying the pot till

MOSFET get turned on, with the indication that drain current getting constant value.

5. Note down the values of gate-source voltage (VGS) and the drain current (I D) 6. Finally, a graph of gate - source voltage (VGS) Vs drain current (ID) is plotted.



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TABULATION: Drain Characteristics:

S.No. VGS1 = VGS2 = VGS3 = VDS(V) ID(mA) VDS(V) ID(mA) VDS(V) ID(mA)

1 2 3 4 5

Transfer Characteristics:

VDS =

S.No. VGS(V) ID(mA)

1 2 3 4 5



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INFERENCE: DISCUSSION QUESTIONS: 1. What is current control device? 2. What is voltage control device? 3. What is the number and range of given MOSFET? 4. Draw the symbol of MOSFET? 5. What is Transconductance? 6. How to find the output resistance? RESULT:



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VI CHARACTERISTICS OF IGBT

CIRCUIT DIAGRAM: VI CHARACTERISTICS

MODEL GRAPH:



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VI CHARACTERISTICS OF IGBT

AIM: (i) Obtain the steady – state output – side characteristics and transfer

characteristics of the given IGBT, for a specified value of gate – source voltage. (ii) Identify whether given switch is MOSFET or IGBT by finding the

output– side characteristics.


1 IGBT module IRGBC 600V,10A 1 2 Ammeter MC (0-100) mA 1 3 Voltmeter MC (0-10)V 1 4 Voltmeter MC (0-30) V 1 5 CRO - - 1 6 CRO Probe - - 1 7 Patch Cards - - 10

FORMULA USED: 1. Trans conductance

CE

Cm V

IG ∆∆

= mho

2. Output resistance C

CECE I

VR ∆∆

= ohm Where: ∆IC = Change in collector current. ∆VCE = Change in collector to emitter voltage PRECAUTION:

The initial set gate voltage should be taken as minimum in order to take the consecutive readings.

PROCEDURE: DRAIN CHARACTERISTICS

1. Connections are made as per the circuit diagram 2. Switch on the 230V AC supply through three-pin power chord. 3. Keep the gate - emitter voltage (VGE) to a suitable value (say minimum of 6V to

7V)



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TABULATION:

S.No. VGE1 = VGE2 = VGE3 = VCE(V) IC(mA) VCE(V) IC(mA) VCE(V) IC(mA)

1 2 3 4 5



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4. Now slowly increase the drain-source voltage (VDS) by varying the pot till MOSFET get turned on, with the indication that drain-source voltage decreases to it on state voltage drop.

5. Note down the values of drain-source voltage (VDS) and the drain current (I D) 6. For various gate-source voltage take the different set of readings and tabulate it. 7. Finally, a graph of drain-source voltage (VDS) Vs drain current (ID) is plotted for

various gate-source voltage. INFERENCE: DISCUSSION QUESTIONS: 1. What is current control device? 2. What is voltage control device? 3. What is the number and range of given IGBT? 4. Draw the symbol of IGBT? 5. What are differences between Transistor, MOSFET and IGBT? 6. How to find the given device is whether MOSFET or IGBT? RESULT:



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TRANSIENT CHARACTERISTICS OF MOSFET AND SCR CIRCUIT DIAGRAM: FOR MOSFET

MATLAB CIRCUIT FOR MOSFET



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TRANSIENT CHARACTERISTICS OF MOSFET AND SCR

AIM: (i) Obtain and explain both turning ‘ON’ and turn ‘OFF’ characteristics of

given SCR (ii) Obtain and explain both turning ‘ON’ and turn ‘OFF’ characteristics of

given MOSFET.

APPARATUS REQUIRED: S.No. Blocks Type Items Quantity

1 Simulink i. Sink Scope 1

ii. Source Pulse Generator 1 2 Sim power system

i. Measurements MC Ammeter 1 MC Voltmeter 1

ii. Elements - RLC series branch 1 iii. Power electronics - MOSFET 1

- SCR 1 iV. Electrical source - DC source 1

PROCEDURE: FOR MOSFET

1. Open MATLAB and open Simulink then create a new file (new module) 2. Connections are made as per the circuit diagram by taking the required items

from the corresponding blocks. 3. According to the MOSFET, we should give the block parameter for MOSFET,

RLC series branch, pulse generator and the scope. 4. Now simulate the circuit. The graph of Gate pulse, Drain current and drain to

source voltage can be shown. 5. Finally the print out of the MATLAB circuit and the output is taken.



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FOR SCR

MATLAB CIRCUIT FOR SCR



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FOR SCR

1. Open MATLAB and open Simulink then create a new file (new module) 2. Connections are made as per the circuit diagram by taking the required items

from the corresponding blocks. 3. According to the SCR, we should give the block parameter for SCR, RLC series

branch, pulse generator and the scope. 4. Now simulate the circuit. The graph of Gate pulse, Anode current and anode to

cathode voltage can be shown. 5. Finally the print out of the MATLAB circuit and the output is taken.



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MODEL GRAPH: FOR MOSFET

FOR SCR



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INFERENCE: DISCUSSION QUESTIONS: 1. What is MATLAB? 2. What is a transient characteristic? 3. What is commutation? 4. Where the natural commutation is not possible in SCR? 5. What is the function of scope in MATLAB? RESULT:



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SINGLE PHASE AC TO DC FULLY CONTROLLED CONVERTER

CIRCUIT DIAGRAM FOR R LOAD

Model graph for R Load (αααα = 30°°°°, R=100ΩΩΩΩ)



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SINGLE PHASE AC TO DC FULLY CONTROLLED CONVERTER AIM:

(i) To study the operation of single phase fully controlled bridge converter with R and R-L loads for continuous and discontinuous conduction modes.

(ii) Also find the performance parameters (Rectification efficiency, form factor, peak inverse voltage and ripple factor)


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

FORMULA USED:

For R load 1. Average dc output voltage Vdc is )cos1( απ += m

dcVV


22sin

21

+−= ααππmrms VV

For R-L 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



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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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General Formula: 5. Rectification efficiency 2

2%

rms

dcVV

=η

6. Form factor dc

rmsVVFF =


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


Procedure:

1. Connections are made as per the circuit diagram for R load 2. Switch on the triggering kit 3. Switch on the 230 V 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 RL load.



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Tabulation for R load:

Vs= R=

S.No. Firing Angle αααα in degree

Idc Measured in milliamps

Vdc Measured in volts

Vdc Calculated in volts

Vrms Calculated in volts

Tabulation for RL load:

Vs= R= L= ββββ=

S.No. Firing Angle αααα in degree

Idc Measured in milliamps




Continuous conduction

Discontinuous conduction



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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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SINGLE PHASE AC TO DC HALF CONTROLLED CONVERTER

CIRCUIT DIAGRAM FOR R LOAD

Model graph for R Load (αααα = 30°°°°, R=100ΩΩΩΩ)



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SINGLE PHASE AC TO DC HALF CONTROLLED CONVERTER AIM:

(i) To study the operation of single phase semi converter with R and R-L loads for continuous and discontinuous conduction modes.

(ii) Also find the performance parameters (Rectification efficiency, form factor, peak inverse voltage and ripple factor)


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

dcVV


22sin

21

+−= ααππmrms VV

General Formula: 3. Rectification efficiency 2

2%

rms

dcVV

=η

4. Form factor dc

rmsVVFF =


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




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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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Procedure:

1. Connections are made as per the circuit diagram for RL load 2. Switch on the triggering kit 3. Switch on the 230V 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 RL load.



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Tabulation for R load:

Vs= R= S.No. Firing Angle

αααα in degree Idc Measured in milliamps




Tabulation for RL load: S.No. Firing Angle

αααα in degree Idc Measured in milliamps




Continuous conduction

Discontinuous conduction



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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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STEP DOWN MOSFET BASED CHOPPER

CIRCUIT DIAGRAM

MODEL GRAPH



47

STEP DOWN MOSFET BASED CHOPPER AIM:

To study the waveform for MOSFET based 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 CRO - - 1 7 CRO Probe - - 1 8 Patch cards - - -

FORMULA USED:

1. Average dc output voltage Vdc is sdc VV δ= 2. RMS output voltage Vrms is srms VV δ= Where: δ = Duty cycle of the chopper T

TON=δ TON = on time T = Total time

Procedure:

1. Connections are made as per the circuit diagram. 2. Switch on the RPS 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 and

tabulate it. 6. The output voltage is theoretically calculated. 7. Draw the graph as per the reading in the table.



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TABULATION: Vs= T=

S.No. TON

in ms δδδδ = TTON Idc (Avg)

Measured in mA

Vdc (Avg) Measured

in volts

Vdc (Avg) Calculated

in volts sdc VV δ=

1 2 3 4 5



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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 is step down chopper? 4. What are the control strategies used for choppers? 5. Why frequency modulation is not preferred mostly? 6. Why thyristor is not preferred in chopper circuit mostly?

RESULT:



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STEP UP MOSFET BASED CHOPPER

CIRCUIT DIAGRAM:

Model graph for step up operation



51

STEP UP MOSFET BASED CHOPPER AIM:

To study the waveform for MOSFET based step up 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:

Average dc output voltage Vdc is ( )δ−= 1

sdc

VV Where: δ = Duty cycle of the chopper T

TON=δ TON = on time T = Total time

PROCEDURE:

1. Connections are made as per the circuit diagram 2. Switch on the RPS 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 and

tabulate it. 6. The output voltage is theoretically calculated for each step. 7. Draw the graph as per the reading in the table.



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TABULATION:

Vs= T=

S.No. TON

in ms δδδδ = TTON Idc (Avg)

Measured in mA

Vdc (Avg) Measured

in volts

Vdc (Avg) Calculated

in volts

( )δ−= 1s

dcVV

1 2 3 4 5



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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 is step up chopper? 4. What are the control strategies used for choppers? 5. Why frequency modulation is not preferred mostly? 6. Why thyristor is not preferred in chopper circuit mostly?

RESULT:



54

IGBT BASED SINGLE PHASE PWM INVERTER

CIRCUIT DIAGRAM



55

IGBT BASED SINGLE PHASE PWM INVERTER AIM:

To study the operation of single-phase bridge inverter with sinusoidal pulse width modulation 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.



58

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



59


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:



60

SERIES RESONANT DC-DC CONVERTER (ZERO CURRENT SWITCHING)

CIRCUIT DIAGRAM:

MODEL GRAPH:



61

SERIES RESONANT DC-DC CONVERTER (ZERO CURRENT SWITCHING)

AIM:

To determine the voltage and current wave form of series resonant dc-dc converter (Zero current switching).


1 Resonant converter module VPET-315 - 1 2 Ammeter MC (0-2) A 1 3 Voltmeter MC (0-30) V 1 4 CRO - - 1 5 CRO Brobe - - 1 6 Patch Cards - - 10

FORMULA USED: Frequency Tf 1= Hz Where: T= Time f = Frequency PRECAUTIONS:

Initially keep the frequency adjustment POT in minimum position PROCEDURE:

1. Connections are made as per the circuit diagram. 2. Initially keep frequency adjustment POT in minimum position. 3. Switch on the main supply 4. Connect the “P” Pin connector from PWM output and PWM input\ 5. Connect the banana connector P10 to P4 , P8 to P11 6. Connect the current sensing resistor (1Ω / 20 W) across the banana connector P2

to P3. 7. The voltmeter is connected across P5 and P12



62

TABULATION:

S.No. Time (ms) Switching Frequency

(KHz) Output

Voltage (V) Output

Current (A) 1 2 3 4 5



63

8. Connected the R load across P5 and P12 through ammeter. 9. Adjust the frequency POT and set switching frequency 40KHz. 10. Connect the CRO across the connector T1 (+) and ground. Another channel is

connected to P2 (+), P3 (-) 11. Now observe the switch voltage and current wave. 12. Similarly observe the switch voltage and current waveform for various switching

frequency. INFERENCE: DISCUSSION QUESTIONS: 1. What is resonance? 2. What is the condition for resonance? 3. What are the advantages of resonant converter? 4. What is soft switching? 5. What types of resonant converter? 6. What is zero current switching? 7. What is zero voltage switching? RESULT:



64

PARALLEL RESONANT DC-DC CONVERTER (ZERO VOLTAGE SWITCHING)

CIRCUIT DIAGRAM:

MODEL GRAPH:



65

PARALLEL RESONANT DC-DC CONVERTER (ZERO VOLTAGE SWITCHING)

AIM:

To determine the voltage and current wave form of parallel resonant dc-dc converter (Zero voltage switching).


1 Resonant converter module VPET-315 - 1 2 Ammeter MC (0-2) A 1 3 Voltmeter MC (0-30) V 1 4 CRO - - 1 5 CRO Brobe - - 1 6 Patch Cards - - 10

FORMULA USED: Frequency Tf 1= Hz Where: T= Time f = Frequency PRECAUTIONS:

Initially keep the frequency adjustment POT in minimum position PROCEDURE:

1. Connections are made as per the circuit diagram. 2. Initially keep frequency adjustment POT in minimum position. 3. Switch on the main supply 4. Connect the “9” Pin connector from PWM output and PWM input\ 5. Connect the banana connector P10 to P4, P8 to P11 6. Connect the current sensing resistor (1Ω / 20 W) across the banana connector P2

to P3. 7. The voltmeter is connected across P5 and P12



66

TABULATION:

S.No. Time (ms) Switching Frequency

(KHz) Output

Voltage (V) Output

Current (A) 1 2 3 4 5



67

8. Connected the R load across P5 and P12 through ammeter. 9. Adjust the frequency POT and set switching frequency 40KHz. 10. Connect the CRO across the connector T1 (+) and ground. Another channel is

connected to P2 (+), P3 (-) 11. Now observe the switch voltage and current wave. 12. Similarly observe the switch voltage and current waveform for various switching

frequency. INFERENCE: DISCUSSION QUESTIONS: 1. What is resonance? 2. What is the condition for resonance? 3. What are the advantages of resonant converter? 4. What is soft switching? 5. What types of resonant converter? 6. What is zero current switching? 7. What is zero voltage switching? RESULT:

Muthayammal Power

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