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Power Electronics & Simulation Lab, EEE

ST.PETER’S ENGINEERING COLLEGE

ST. PETER’S ENGINEERING COLLEGE

(Approved by AICTE, Affiliated to JNTU Hyderabad)

Opp: AP Forest Academy, Dhullapally, Near Kompally, Secunderabad - 500010

DEPARTMENT

OF

ELECTRICAL AND ELECTRONICS ENGINEERING

Name of the course : Power electronics lab

Name of the Dept. : ELECTRICAL AND ELECTRONICS ENGINEERING

Name of the Faculty : G MOHANKRISHNA, Assistant Professor

Class : III Year B.Tech. EEE, II – Sem

Academic year : 2018-19

SPEC/EEE/UG/CF-0403/2018 – 19



CERTIFICATE OF AUTHENTICATION

This is to certify that K.V.V.Nagababu,Assistant professor of Electrical and Electronics

Engineering Department has prepared the course material for Power electronics lab of Jawaharlal Nehru

Technological University, Hyderabad for the academic year 2018 –19. The contents of this

course/teaching module have not been reproduced elsewhere in any books or journals.

This is the sole property of St. Peter’s Engineering College, Hyderabad to be referred by staff and

students.

Name of the Faculty: G Mohankrishna

HOD

(EEE department)

Signature



INSTITUTE VISION

Our vision is to promote quality education accessible to all sections of the Society without any

discrimination of caste, creed, color, sex and religion and help students discover their true potential.

INSTITUTE MISSION

M1.To provide integrated, continuous and wholesome development of students by

equipping them with knowledge and skills, social values and ethics, scientific attitude and orientations for

lifelong education and mold them into useful citizens of the society.

M2. To create an environment conductive to inhibiting theirs total involvement and participation of the

students, faculty, staff and management. In making the institution into a center of excellence imparting

quality technical education and also arms the students with the competence to be at the forefront of cutting

edge technology and entrepreneurship in highly competitive global market.



Department of Electrical and Electronics Engineering

DEPARTMENT VISION

To Evolve the department as a centre of excellence in Electrical and Electronics Engineering education in

the country, to train students in contemporary technologies to meet the needs of global industry and to

develop them into skilful engineers imbued with knowledge of core as well as inter-disciplinary domains,

human values and professional ethics.

DEPARTMENT MISSION

•Impart quality education to the students to enter a dynamic and rapidly changing field with career

opportunities in Electrical Power System, Electronics and Software Professional.

•Electrical and Electronics Engineering Department was found with a threefold mission in teaching,

research, and public service. Based on that foundation, the mission of the Department, in all major fields of

Electrical and Electronics Engineering, is to instill in students the attitudes, values, vision, and training that

will prepare them to learn and to lead continuously for life-time.

•Develop the ability and passion to work creatively, effectively and wisely for the benefit of society.

•Generate new knowledge for the betterment of humankind and to utilize it universally.

•Generate realistic and innovative solutions for the current needs and future technological needs and to play

a leading role to form the van of social and scientific progress and to provide special services where there

are needs that the department is uniquely qualified to meet.

•Other than the Academic curriculum, the department also engages in regular Industrial Visits and In-plant

training for students to gain industrial exposure and practical knowledge.

\




Program Educational Objectives (PEOs):

1. PEO1: To provide a solid foundation in Mathematics, Science, Electrical, Electronics and allied engineering,

capable of analyzing, design and development of systems for Energy Generation, Transmission,

Distribution, Operation and Control.

2. PEO2: To prepare the student for a successful career in industry/Technical profession and undertake post-

graduation studies, research and lifelong learning.

3. PEO3:

To prepare the student to fulfill the needs of society in solving technical problems using engineering

principles, tools and practices.

4. PEO4: To equip student with the knowledge of modern simulation tools to solve complex Engineering

problems.

5. PEO5:

To inculcate professional and ethical attitudes, team work skills, leadership qualities and good oral and

written communication skills.



Program Outcomes (POs):

1. ENGINEERING KNOWLEDGE: Apply the knowledge of mathematics, science, engineering

fundamentals, and an engineering specialization to the solution of complex engineering problems.

2. PROBLEM ANALYSIS:Identify, formulate, research literature, and analyze complex engineering

problems reaching substantiated conclusions using first principles of mathematics, natural sciences,

and engineering sciences.

3. DESIGN/DEVELOPMENT OF SOLUTIONS:Design solutions for complex engineering

problems and design system components or processes that meet the specified needs with appropriate

consideration for the public health and safety, and the cultural, societal, and environmental

considerations.

4. CONDUCT INVESTIGATIONS OF COMPLEX PROBLEMS:Use research-based knowledge

and research methods including design of experiments, analysis and interpretation of data, and

synthesis of the information to provide valid conclusions.

5. MODERN TOOL USAGE:Create, select, and apply appropriate techniques, resources, and modern

engineering and IT tools including prediction and modelling to complex engineering activities with

an understanding of the limitations.

6. THE ENGINEER AND SOCIETY:Apply reasoning informed by the contextual knowledge to

assess societal, health, safety, legal and cultural issues and the consequent responsibilities relevant to

the professional engineering practice.

7. ENVIRONMENT AND SUSTAINABILITY:Understand the impact of the professional

engineering solutions in societal and environmental contexts, and demonstrate the knowledge of, and

need for sustainable development.

8. ETHICS:Apply ethical principles and commit to professional ethics and responsibilities and norms

of the engineering practice.

9. INDIVIDUAL AND TEAM WORK:Function effectively as an individual, and as a member or

leader in diverse teams, and in multidisciplinary settings.

10. COMMUNICATION:Communicate effectively on complex engineering activities with the

engineering community and with society at large, such as, being able to comprehend and write

effective reports and design documentation, make effective presentations, give and receive clear

instructions.

11. PROJECT MANAGEMENT AND FINANCE:Demonstrate knowledge and understanding of the

engineering and management principles and apply these to one’s own work, as a member and leader

in a team, to manage projects and in multidisciplinary environments.

12. LIFE-LONG LEARNING:Recognize the need for, and have the preparation and ability to engage

in independent and life-long learning in the broadest context of technological change.

Programme specific outcomes (PSOs):

PSO 1. An ability to endeavor the public and private sector, national level examination and interviews

successfully.

PSO2. An ability to design solutions for Electrical transmission and distribution systems.

PSO3. An ability to undertake research in power electronics and power systems.




Name of the Faculty: G Mohankrishna Class: III EEE-Ii SEM

Course Name: PE Lab( EE605PC) Academic Year: 2018-19

COURSE OBJECTIVES (CEOs)

EXP OBJECTIVES

1 To provide the students a deep insight in to the working of different switching devices with

respect to their characteristics

2 To analyze different converters and control with their applications.

3 To Provide the students a knowledge on PSpice simulation.

4 To provide students with a strong back ground in different types of controllers.

5 To train the students to have a solid foundation in mathematical and engineering

fundamentals to solve engineering problems

COURSE OUTCOMES (Cos)

Upon completion of this course, students will have an opportunity to learn about the

following.

MODULES OUTCOMES POs PEOs SCR, IGBT and MOSFET

characteristics Understands the VI Characteristics of SCR,

, IGBT and MOSFET.

a,b,c,d,i,k l

m n

I,II,IV,V

Gate firing circuits for SCR’s Knows about the design of different firing

circuit of an SCR’s.

a,b,c,d,,i,k l

m n

I,II,V

Single Phase AC Voltage

Controller

Analyze a circuit for converting 3 phases to

2 phase supply.

a,b,c,d,k l

m n

I,II,IV,V

Single Phase Fully

Controlled Converter

Analyze a circuit for converting fixed AC

voltage to variable DC voltage.

a,b,c,d,k l

m n

I,II,IV,V

Single Phase Half Controlled

Bridge Converter

Analyze a circuit for converting fixed AC

voltage to variable DC voltage.

a,b,c,d,k l

m n

I,IV,V

Forced Commutation Circuits

Understands the basic turnoff technique and

Analyzes different commutating

techniques.

a,b,c,d,k l

m n

I,II,V

Parallel Inverter Understands and able to design a Parallel

Inverter.

a,b,c,d,k l

m n

I,III,V

Jones Chopper Designs a Jones Chopper for different

practical load applications

a,b,c,d,k l

m n

I,III,V

Single Phase Cyclo

Converter

Designs Single Phase Cyclo Converter for

different loads.

a,b,c,d,k l

m n

I,II,III,IV,V

Single phase half-controlled

bridge converter with R &

RL load

Analyze and simulate the 1- half-

controlled Bridge Inverter.

a,b,c,d,e,,i,k

l m n

I,IV,V

Simulation on single phase ac Analyze and simulate the 1- fully a,b,c,d,e,k l I,IV,V



voltage controller and fully

controlled bridge converter

with R & RL load using p-

spice

Controlled Converter m n

Spice simulation of single

phase full converter circuits

R, RL & RLE loads)

Analyze and simulate the 1- full

Converter

circuits

a,b,c,d,k l

m n

I,III,V

Simulation on resonant pulse

commutation circuit using

p-spice

Analyze and simulate resonant pulse

commutation circuit

a,b,c,d,k l

m n

I,II,V

Single Phase Dual Converter With R & Rl Load

Analyze a circuit with circulating and non

circulating current modes

a,b,c,d,e,k l

m n

I,IV,V

LIST OF EXPERIMENTS

Programme: B.Tech-EEE

Lab Title: Power Electronics Lab

Lab i/c: G MOHANKRISHNA

Title of Lab Class as in Sylabus: Power Electronics Lab

Year/Course/Branch/Sem:

III/B.Tech/EEE/II

No. of Experiments ( As per sylabus) : 10 Additional No. of Experiments

Proposed:02

List of Experiments

1 STUDY OF CHARACTRISTICS OF SCR, MOSFET, IGBT

2 GATE FIRING CIRCUITS FOR SCR

3 1-Ф AC VOLTAGE CONTROLLER With R & RL Load

4 SINGLE PHASE FULLY CONTROLLED BRIDGE CONVERTER WITH R & RL LOAD

5 FORCED COMMUTATION CIRCUITS(Class A, Class B, Class C and Class D)

6 DC JONE’S CHOPPER WITH R & RL LOADS

7 SINGLE PHASE PARALLEL INVERTER WITH R AND RL LOADS

8 SINGLE PHASE CYCLO-CONVERTER WITH R & RL LOADS

9 SINGLE PHASE HALF-CONTROLLED BRIDGE CONVERTER

WITH R & RL LOAD



10 SIMULATION ON SINGLE PHASE AC VOLTAGE CONTROLLER AND FULLY

CONTROLLED BRIDGE CONVERTER WITH R & RL LOAD USING P-SPICE

11 PSPICE SIMULATION OF SINGLE PHASE FULL CONVERTER CIRCUITS(R, R-L & R-L-

E LOADS)

12 SIMULATION ON RESONANT PULSE COMMUTATION CIRCUIT USING P-SPICE

13 THREE PHASE FULLY-CONTROLLED BRIDGE CONVERTER WITH R & RL LOAD

14 SINGLE PHASE DUAL CONVERTER WITH R & RL LOAD

DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING

POWER ELECTRONICS LAB

INDEX

SI. No: NAME OF THE EXPERIMENTS Page No

1 STUDY OF CHARACTRISTICS OF SCR, MOSFET, IGBT 01-11

2 GATE FIRING CIRCUITS FOR SCR 12-15

3 1-Ф AC VOLTAGE CONTROLLER WITH R & RL LOAD 16-20

4 SINGLE PHASE FULLY CONTROLLED BRIDGE CONVERTER WITH R & RL LOAD 21-24

5 FORCED COMMUTATION CIRCUITS(Class A, Class B, Class C and Class D) 25-29

6 DC JONE’S CHOPPER WITH R & RL LOADS 30-33

7 SINGLE PHASE PARALLEL INVERTER WITH R AND RL LOADS 34-37

8 SINGLE PHASE CYCLO-CONVERTER WITH R & RL LOADS 38-41

9 SINGLE PHASE HALF-CONTROLLED BRIDGE CONVERTER WITH R & RL LOAD 42-45

10 SIMULATION ON SINGLE PHASE AC VOLTAGE CONTROLLER AND FULLY

CONTROLLED BRIDGE CONVERTER WITH R & RL LOAD USING P-SPICE 46-49

ADDITIONAL EXPERIMENTS

11 PSPICE SIMULATION OF SINGLE PHASE FULL CONVERTER CIRCUITS(R, R-L & R-

L-E LOADS) 50-55

12 SIMULATION ON RESONANT PULSE COMMUTATION CIRCUIT USING P-SPICE 56-57

13 THREE PHASE FULLY-CONTROLLED BRIDGE CONVERTER WITH R & RL LOAD 58-60

14 SINGLE PHASE DUAL CONVERTER WITH R & RL LOAD 61-64



INCHARGE HOD

Dept. of EEE

Faculty in-charge


Name of the Faculty: G MOHANKRISHNA Class: III EEE-II SEM

Course Name: PE LAB Academic Year: 2018-19

INDIVIDUAL FACULTY TIME-TABLE

Day/

Hour

1

(9.00AM

-

9.50AM)

2

(9.50AM

-

10.40AM

)

3

(10.40A–

11.30AM

)

4

(11.30AM

- 12.20

PM)

LUNC

H

5

(1.00PM

-

1.50PM)

6

(1.50PM

- 2.40

PM)

7

(2.40PM

-

3.30PM)

8

(3.30PM

-

4.20PM)

MO

N

1 Batch

TUE

WE

D

THU

FRI 2 Batch

SAT

FACULTY SIGN TIME TABLE I/C HOD



Lab External Exam Questions:

Exp No, Question

1 Experimantally prove 1-ϕ cycloconverter step down operation

2 Experimantally prove 1-ϕ AC Voltage controller with R-load.

3 Experimantally prove 1-ϕ full wave bridge rectifier operation

4 Experimantally prove 1-ϕ half controlled bridge rectifier operation

5 Experimantally prove series inverter operation

6 Experimantally prove parallel inverter operation.

7 Write a program in simulik , verify AC Voltage controller operation

8 Write a program in simulik , verify sinle phase half controller operation

9 Experimantally prove R,RC-trigerring methods operation

10 Experimantally prove UJT method operation

11 Experimantally prove step-down chopper operation

12 Experimentally prove operation of DC Jones chopper operation

Faculty in-charge

B-Tech III Year II Sem pe Lab External Exam Time Table for the Year 2018-2019

DATE:

BRANCH NAME OF THE

LABORATORY

NO. OF

STUDENTS REG. NO.

DATE OF

EXAM

EXTERNAL

EXAMINORS TIMINGS

EEE PE

EEE PE

EEE PE

EEE PE



COORDINATOR

HOD

DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING

EE605PC: POWER ELECTRONICS LAB LAB

SCHEDULE

BATCH/

WEEK

B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 B11

W1 E1 E2 E3 E4 E5 E6 E7 E8 E9 E10 E1

W2 E2 E3 E4 E5 E6 E7 E8 E9 E10 E1 E2

W3 E3 E4 E5 E6 E7 E8 E9 E10 E1 E2 E3

W4 E4 E5 E6 E7 E8 E9 E10 E1 E2 E3 E4

W5 E5 E6 E7 E8 E9 E10 E1 E2 E3 E4 E5

W6 E6 E7 E8 E9 E10 E1 E2 E3 E4 E5 E6

W7 E7 E8 E9 E10 E1 E2 E3 E4 E5 E6 E7

W8 E8 E9 E10 E1 E2 E3 E4 E5 E6 E7 E8

W9 E9 E10 E1 E2 E3 E4 E5 E6 E7 E8 E9

W10 E10 E1 E2 E3 E4 E5 E6 E7 E8 E9 E10

W11 E1 E2 E3 E4 E5 E6 E7 E8 E9 E10 E1

W12 E2 E3 E4 E5 E6 E7 E8 E9 E10 E1 E2

BATCH ROLL NO.(MONDAY) ROLL NO.(FRIDAYDAY)

B1 16Bk1A0201,202,203 16Bk1A0228,229,230

B2 16Bk1A0204,205,206 16Bk1A0231,233,234

B3 16Bk1A0207,208,209 16Bk1A0235,236,237

B4 16Bk1A0210,211,212 16Bk1A0238,239,240

B5 16Bk1A0213,215,216 16Bk1A0241,242,243

B6 16Bk1A0217,218,220 16Bk1A0244,245,246

B7 16Bk1A0221,222,223 16Bk1A0247,248,249

B8 16Bk1A0224,226,227 16Bk1A0250,17BK5A0211,212

B9 17BK5A0201,202,203 17BK5A0214,215,216

B10 17BK5A0204,205,206 17BK5A0217,218,219

B11 17BK5A0207,208,209,210 17BK5A0220,221,222



List of Working Models

Academic Year: 2018-19, Semester: EVEN

Laboratory Name: PE Lab Room No.:

S.NO. PROJECT TYPE NAME OF THE

STUDENT

UNIVERSITY

ROLL NO

Faculty-in-charge HOD



Department of Electrical & Electronics Engineering

PE Lab

Code of conduct for the laboratory

All students must observe the Dress code while in the laboratory

Sandals or open-toed shoes are NOT allowed

Foods, drinks and smoking are NOT allowed

All bags most be left at the indicated place

The lab timetable must be strictly followed

Be PUNCTUAL for your laboratory session

Experiment must be completed within the given time

Noise must be kept to a minimum

Workspace must be kept clean and tidy at all time

Handle all apparatus with care

All students are liable for any damage to equipment due to their own negligence

All equipment, apparatus, tools and components must be RETURNED to their original place after

use

Students are strictly PROHIBITED from taking out any items from the laboratory

Students are NOT allowed to work alone in the laboratory without the lab supervisor

Report immediately to the lab supervisor if any injury occurred

BEFORE LEAVING LAB:

Place the stools under the lab bench

Turn off the power to all instruments

Turn off the main power switch to the lab bench

Please check the laboratory notice board regularly for updates



Lab Incharge

PE LAB LAYOUT – Area in 105 Sq.M

Exp. No.:

Date :

1. STUDY OF CHARACTRISTICS OF SCR, MOSFET, IGBT

A) CHARACTERISTICS OF SCR

Aim: - 1. To get the characteristics of the SCR for different gate currents.

2. To obtain the Holding current and Latching current of the SCR

66” ft

64” ft

Area : 4,224” sqft

Lab capacity : 36 Students



Exp. No.:

Date :

1. STUDY OF CHARACTRISTICS OF SCR, MOSFET, IGBT

A) CHARACTERISTICS OF SCR

Aim: - 1. To get the characteristics of the SCR for different gate currents.

2. To obtain the Holding current and Latching current of the SCR

Apparatus: -

s.no Item Quantity

1. SCR, MOSFET ,IGBT Characteristics Kit 1N o

2 Patch Cards Adequate

Theory:-

SCR is a four layer, three terminals, three junctions, PNPN structure power Semiconductor device. Its

three terminals have been named as Anode (A), Cathode (K), and Gate (G).When the anode voltage is positive with

respect to the cathode, the junctions J1and J3 are forward biased. The junction J2 is reverse biased and only leakage

current flows from anode to cathode. The SCR is said to be in forward blocking or OFF state and the leakage current is known as

off state current.

If the anode to cathode voltage VAK is increased to a sufficiently large value, the reverse biased

junction J2 will break. This is known as avalanche breakdown, and the corresponding voltage is called forward

breakdown voltage, VB0. Since other junctions J1and J3 are already forward biased, there will be free movement of

carriers across the three junctions, resulting in large forward anode current. The device will then be in a conduction state

or ON state. The voltage drop would be due to the ohmic drop in the four layers and it is small, typically 1 Volt. In the on-

state, the anode current is limited by the external impedance or load resistance (RL). The anode current must be more

than a value known as latching current IL, to maintain the required amount of carrier flow across the junction.

Otherwise the device will revert to the blocking condition as the anode to cathode voltage is reduced .The device will

continue to conduct because there is no depletion layer on the junction J2 due to free movement of carriers. However,

if the anode current is reduced below a level known as the Holding current IH, a depletion region develops around the

junction J2 due to reduced number of free carriers and the SCR would be in blocking state. The holding current is in the

order of milli-amperes and is less than the latching current IL.

When the cathode voltage is positive w.r.t. anode, junction J2 is forward biased and junctions J1and

J3 are reverse biased .The SCR will be in reverse blocking state and reverse leakage current known as reverse current IR



would flow through the device. Although an SCR can be turned on by increasing the forward voltage beyond VBO,

such a turn on could be destructive. In practice, the forward voltage is maintained below VBO, and SCR is turned on by

applying a positive voltage between the gate and the cathode.

Circuit diagram:-

Procedure:-

a) SCR characteristics

1. The connections are made as shown in the circuit diagram

2. Switch on the regulated power supply. Apply constant VAK Voltage say 10 V by varying VAA

3. Gradually increase the gate current till the SCR becomes on.i.e VAK and IA are noted.

4. Now VAK is increased gradually and IA noted for two or three readings.

5. Steps 3 to 4 are repeated for another value of VAK say 30 V.

6. Tabulate the readings in the table.

7. Plot a graph of VAK verses IA for different (two) values of IG

b) To get Latching current:-

1. Keep proper VAK to trigger SCR by gate current. Trigger SCR by applying gate current. Keep sufficient load current by varying load resistance in fully anti clock wise direction.

2. Now reduce the load current slowly and check SCR is still under on by removing gate current.

3. If the SCR is under ON insert gate current further and reduce the load current again.

4. Step (3) is repeated till the SCR jumped to blocking state by removing and inserting gate current.

5. The minimum current for which SCR suspend under ON condition is noted which is latching current IL.

c) To get holding current



1. Keep proper VAK to trigger SCR by gate current. Trigger SCR by applying gate current. Keep sufficient load current by varying load resistance in fully clock wise direction.

2. Open the gate circuit, now reduce the load current till SCR jump to blocking state.

3. The minimum current for which SCR suspend under ON condition is noted which is holding current IH

Observations:-

I G1= I G2 =

S.No VAK Volts IA mA

S.No VAK

Volts

IA

mA



Model graph:-

Precautions:-

1) Ensure that connections are given properly before switching on power supply.

2) The readings must be noticed carefully without parallax error.

3) The student must wear leather chapels or shoes in the laboratory.

4) One must be aware of first-Aid techniques for electric-shock



Review Questions:-

1. How many methods of gate control are available for triggering SCRs &what are they?

2. What are the different operating regions of SCR? And explain them?

3. Give some industrial applications of the SCR?

Result:-



B) CHARACTERISTICS OF POWER MOSFET & IGBT

Aim: - To study the static characteristics of MOSFET & IGBT.

Apparatus:-

Theory:-

Metal Oxide Silicon Field Effect Transistor (MOSFET) is a majority carrier and voltage controlled device.

It has three terminals namely Drain, Source and Gate .It is switched on by applying a positive voltage pulse to the

gate and switched off by withdrawing the voltage pulse. The gate terminal draws current only to change the gate -

source capacitance. The MOSFET is fastest of all devices and can operate at frequency of hundreds of KHZ. The device

is generally used for very low power inverters for UPS and switching power supplies. It is rarely used for power

converters (above few KWs) because of large conduction drop. High voltage and high current devices are not

available. As the voltage rating increases the device drop increases. MOSFETs of high rating e.g. l00V - 250 A, 600V - 40

A are available presently.

Presently, Insulated Gate Bipolar Transistor (IGBT) is the most preferred device for low medium and

high power inverters. It has gained popularity because it possesses most of the characteristics which are expected

from a near ideal power switching device. An IGBT is basically a hybrid MOS-Gated turn on-off bipolar transistor. The

IGBT has high speed and high input impedance characteristics of MOSFET and high conductivity characteristics of the

BJT. It can be switched on by applying a positive voltage across its gate-emitter terminals, and this positive voltage

is maintained as long as the device is to be in conducting state. A pulse of current is drawn by the gate terminal from

the gate drive circuit only during the initial switching on process for charging the gate-emitter capacitance and there

S.No Item

Quantity

1. SCR, MOSFET ,IGBT Characteristics Kit 1N o

2. Connecting probes Adequate



after the current drawn is of few milli-amperes. The removal of gate-emitter voltage switches off the IGBT.

However, in order to increase the speed and reliability of operation of IGBT in an inverter, a negative voltage is

maintained across the gate-emitter terminals during off period. The switching speed of IGBT is one order higher than

that of BJT. The device has higher current density compared to BJT and MOSFET. Its input capacitance is significantly

less than that of MOSFET. Presently, IGBTs of rating up to 3.3 kv, 1200A and 1700V, 2400A are available.

Circuit Diagram:-

MOSFET Circuit diagram



IGBT Circuit diagram

Procedure:-

a) Power MOSFET

Output Characteristics

1. Connections are made as shown in circuit diagram.

2. Switch on the equipment. Keep VDS say 10 V vary VGS note down the range of VGS for which drain current is

varying for constant VGS.

3. Keep VGS constant (VGS must within the range determine by step (2)).

4. Vary VDS in steps note down corresponding ID.

5. Step 4 is repeated for different VGS.

6. Tabulate the readings in table.

7. Plot a graph of ID against VDS for different VGS

Transfer Characteristics

1. Connections are made as shown in circuit diagram

2. Switch on the regulated power supplies. Keep VDS constant say 10 V varying VGS in steps, note down the

corresponding ID.


4. Plot a graph of ID Vs VGS

b) IGBT:-


1. Connections are made as shown in circuit diagram.

2. Switch on the equipment. Keep VCE say 10 V vary VGE note down the range of VGE for which collector current

is varying for constant VCE.



3. Keep VGE constant (VGE must within the range determine by step(2)).

4. Vary VCE in steps note down corresponding IC.

5. Adjust VCE to constant while doing step(4)

6. Step 4 is repeated for different VGE.


8. Plot a graph of IC against VCE for different VGE


1. Connections are made as shown in circuit diagram

2. Switch on the regulated power supplies. Keep VCE constant varying VGE in steps, note down the

corresponding IC.

3. Adjust VCE to constant while doing step(2)


5. Plot a graph of IC Vs VGE for constant Vce.

Tabular columns


MOSFET

Sl.No

VGS1 = VGS2 =

VDS ID VDS ID

Sl.No VGEI = VGE2 =



IGBT

VCE Ic VCE Ic




MOSFET

Sl.NO

VDS1

VGS in V ID in mA

IGBT

Sl.NO

VCE=

VGE in V IC in mA



Model graphs:-

a) MOSFET

Output characteristics Transfer characteristics

b)IGBT



Output characteristics Transfer characteristics

Precautions:-

1) Ensure that connections are given properly before switching on the power supply.



Result:-

Review Questions:-

1. What is MOSFET? What are the types of MOSFETs?

2. Discuss pinch off voltage, Threshold voltage, turn on, turn off with reference to MOSFET?

3. What are the advantages & disadvantage of a MOSFET?

4. What is IGBT?

5. IGBT imparts the characteristics of two devices, what are they?

6. Among IGBT, MOSFET, BJT and Thyristor which belongs to current controlled device category. And rest of them belongs to which category?

Exp. No.:

Date :

2.Gate firing circuits FOR scR

Aim:- To study various firing schemes for triggering of SCRs when they are connected in different

converter topologies employing line commutation. They are (a) Resistance firing circuit (b) RC trigger

circuit

Apparatus:-

-

Theory:-

(a) Resistance firing circuit (fig-a):- These are the simplest and most economical. We can vary the

firing angle from 0 to 900 only in R triggering. In this triggering the synchronized firing angle can be

obtained easily and economically in the positive half cycle of the supply. But there is a drawback that the

firing angle can be controlled at the most at 900, because the gate current is in phase with the applied

voltage. A resistor is connected in series with the control pot, so that the gate current does not cross the

maximum possible value Ig max.

S. No Item Type & Range Quantity

1. G a t e f i r i n g u n i t k i t 1 No

2.

Resistive load

5 0 O h ms/ 5A

1 NO

3

CRO 1:1 probe

20MHz

1 NO

1 NO 4. Patch Cards Adequate

(b) RC firing circuits (fig-b):: - The capacitor is connected in the circuit for shifting the phase of the

gate voltage. The capacitor is charged through D2 up to negative peak value of the applied voltage and it

is discharged through pot Rf, resistor R and supply. The value of Rf , R and C are chosen in such a way that

the negative charged capacitor can be discharged fully and can be charged in the positive up to Vg min

between o to 1800 of the positive half cycle . The discharging rate of the capacitor is controlled by the

pot Rf. Observe the variation in the capacitor voltage with respect to the SCR voltage as Rf pot is varied

and note down the minimum and maximum value of the firing angle. We can vary the firing angle from 0

to 1800 approximately.

.

Circuit diagram:-

Procedure:-

(a) Resistance firing circuit:-

1. Connect the circuit diagram as shown in fig (a).

2. Connect a rheostat of 100 Ω /5A between the load points.

3. Vary the control pot and observe the voltage wave forms across load, SCR and at different

Points of the circuit.

4. Draw the wave forms across the load and device for different values of firing angle

(b) RC firing circuit:-

1. Connect the circuit diagram as shown in fig (b)

2. Connect a rheostat of 100 Ω / 5A between the load points.

3. Vary the control pot and observe the voltage wave forms across load, SCR and at different

points of the circuit.

Model Wave forms:-

R-Trigging

RC-Trigging

Result:-

Review Questions:-

1. How many methods of gate controls are available for triggering SCRs?

2. What are they? Compare them and bring out best possible method of pulse generation?

3. What is the purpose of using pulse transformer? What is its turn’s ratio? Will it influence the

quality of gate signal?

Exp. No.:

Date :

3.1-Ф AC VOLTAGE CONTROLLER WITH R & Rl Load

Aim:- To study the operation of an AC voltage controller and observe the output wave forms with R & RL

load

Apparatus:-

Theory:-

If a thyristor switch is connected between AC supply and load, the power flow can be controlled

by varying the rms value of AC voltage applied to the load, and this type of power circuit is known as an

AC voltage controller. The most common applications of ac voltage controller are: Industrial Heating, On-


1. l - φ fully controlled converter power circuit

SCR 1200V/ 25A, 1 No

2. 1 -φ firing unit 1NO

4. Isolation transformer 230/30V, 1 NO

5.

Resistive load

1 0 0 o hm /2 A

1 NO

6

Inductive Load

0-150mH / 2 A,


8 CRO 20MHz 1 NO

load transformer tap-changing, light controls, Speed control of poly phase induction motors and AC

magnet controls. For power transfer, two types of control are normally used:

1. On-off control

2. Phase-angle control.

In on-off control, thyristor switches connect the load to the AC source for a few cycles of input

voltage and then disconnect it for another few cycles. This is trivial in nature and will not be discussed

here. In phase control, thyristor switches connect the load to AC source for a portion of input voltage.

Since the input voltage is AC and thyristors are line commutated, converter grade thyristors are normally

used which are relatively inexpensive and slower than fast–switching thyristors. For applications up to

400Hz, if Triacs are available to meet the voltage and current ratings of a particular application, Triacs

are more commonly used.

Circuit Diagram:-

Fig (a)

Fig (b)

Procedure:-

1. Make the connections as per circuit diagram .Switch on the mains supply to the firing circuit and

observe the trigger out puts by varying firing angle potentiometer and by operating ON/OFF and

SCR/Triac selector switch. Make sure that the trigger pulses are coming properly before

connecting to the power circuit.

2. Connect the trigger pulses from the firing circuit to the corresponding SCRs in the power

ckt.

3. Connect AC supply to the power circuit through step down transformer.

4. Connect 100 ohms / 2A resistive load in Fig (a).

5. Switch ON the power supply and trigger outputs and observe the output voltage wave

Forms across load and SCR.

6. For a given input voltage note down the output voltage and current for different values

of firing angle.

7. Repeat the steps 5 & 6 by connecting the 100mH inductive load in series with 100

Ohms / 2A rheostat.

Observations:-

Input voltage (rms):=

S.No Firing angle Output voltage (Volts)

Observed Calculated

Model Wave forms:-

a) Resistive load

(b)R-L Load

Precautions:-



3) One must be aware of first-Aid techniques for electric shock.

4) If there is no output even after all the proper connections, switch OFF the supply and just

Interchange the connections at step down transformer terminals. This is to make the power

circuit and firing circuit to synchronize.

Result:-

Review Questions:-

1. What is phase angle control? What are the advantages and disadvantages of

phase angle control ?

2. What is the effect of load inductance on the performance of AC Voltage controller?

3. What is the relationship between firing angle and RMS output voltage?

4. What are the applications of A.C voltage controller?

5. What is the semiconductor device that can be used as an AC voltage controller?

6. What are its limitations? How we can turn off SCR in A.C. voltage controller?

Exp. No.:

Date :

4.SINGLE PHASE FULLY CONTROLLED BRIDGE CONVERTER

WITH R & RL LOAD

Aim:-

To study the voltage waveforms across R and RL loads connected to single phase fully

controlled converter.

Apparatus:-

Theory:-

Phase controlled thyristor rectifiers are used to obtain controlled d.c output voltage from

a.c voltage, Since these rectifiers convert a.c to d.c, these controlled rectifiers are also called a.c to

d.c converters. A phase-controlled thyristor is turned on by applying a short pulse to its gate and

turned off due to natural or line commutation. The circuit arrangement of a single phase full

converter is shown. During the positive half cycle, thyristors T1 and T11 are forward biased and

when these two thyristors are fired simultaneously at t = a, the load is connected to the input

supply through T1 and T11.With resistive load T1 and T1

1 will conduct up to t = П and after that

thyristors are turned off due to natural commutation. During the negative half cycle of the a.c


1. l - φ fully controlled converter power circuit

SCR 600V/ 16A, 1 No

2. 1 -φ converter firing unit 1NO

3. Isolation transformer 230V/30V 1 NO

4.

Resistive load

5 0 o hm / 5A

1 NO

5

Inductive Load

0-150mH / 2 A,

1 NO


7 CRO 30 MHz 1 No

input, SCRs T2 and T21 are forward biased and if they were triggered simultaneously, current

flows through the load till t= 2 П and same process repeats for successive cycles.

In case of inductive load, thyristors T, and T11 will continue to conduct beyond t = П, even

though the input voltage is already negative . During the negative half cycle of the input voltage ,the

thyristors T2 and T21 are forward biased and firing of thyristors T2 and T2

1 will apply the supply

voltage across T1 and T11 as reverse voltage . T1 and T1

1 will be turned off due to line or natural

commutation and the load current will be transferred from T1 and T11 to T2 and T2

1 and the same

process repeats for successive cycles. During the period a to П , power flows from the supply to load

and the converter is said to be operated in rectification mode. During the period from П to (П + a),

power flows from the load to supply and converter is operated in inversion mode.

Circuit diagram:-

Procedure:-

1. Connect the input to the power circuit through isolation transformer as given in the connection

diagram.

2. Connect the firing pulses to the SCRs from single phase converter firing unit.

3. Connect the load between positive and negative terminals of the output.

4. Switch ON the firing circuit, switch on the MCB and apply triggering pulses by operating the trigger

outputs ON/OFF switch.

5. Observe the waveforms across different R and RL loads by varying the firing angle.

6. Note down the load voltage and currents for different firing angles for both R and RL loads.

Note: If the output shows zero even after making the connections properly, switch off the input

supply and interchange the input supply terminals. This is to make the input supply to the firing unit

and the power circuit in the same phase. If they are just opposite in phase, none of the SCRs will trigger

and output will be zero.

Observations:-

S.No Input voltage, Vin Firing Angle Load voltage VL

Sample Calculations:-

R-L load :Vo =

mV2cosα , R-load:Vo =

mV2

(1+cos α)

Io = Vo / R

Model

Precautions:-

1. Don’t touch the rectifier output terminals when power card of the power circuit is inserted in

2. Ensure that connections are given properly before switching on the power supply

3. The readings must be noticed carefully without parallax error.

4. One must be aware of first-Aid techniques for electric-shock.

Result:-

Review Questions:-

1. What is a controlled rectifier?

2. What is the principle of phase control?

3. What is a natural or line commutation?

4. What is the inversion mode of converters?

5. What is the rectification mode of converters?

6. Where the freewheeling diode comes in to picture in a fully controlled converter

operation?

Exp. No.:

Date :

5.FORCED COMMUTATION CIRCUITS

(Class A, Class B, Class C and Class D)

Aim:- To study the four types of commutation circuits (Class A, Class B, Class C and Class D)

Appa

ratus:

-

Theory:- Commutation is the process of turning off of a thyristor and it normally causes transfer of

current flow to the other parts of the circuit. Commutation circuit normally uses additional components

to accomplish the turn off, when the input voltage is d.c. This technique is called forced commutation and

normally applied in choppers and inverters. The forced commutation of a thyristor can be achieved by

several ways and they are

1. Series resonant or self commutation (or) Class A

2. Parallel resonant commutation (or) Class B

3. Complementary commutation circuit (or) Class C

4. Auxiliary commutation circuit (or) Class D

5. External pulse commutation circuit (or) Class E

SI.No Item Type / Range Quantity 1. Force commutation kit I No

2. CRO with 1:1 probe 20MHz 1 No

3. Connecting wires Adequate

4 Resistive load 100ohms/1.1A

Circuit diagram:-

Class D

Procedure:-

Class A:-l. Make the connections on the power circuit as shown in the circuit diagram.

2. Connect the trigger output T1 to gate and cathode of SCRT1.

3. Switch on the DC Supply to the power circuit and observe the voltage wave forms across load

by varying the frequency potentiometer.

Class B:- l. Make the connections on the power circuit as shown in the circuit diagram.

2. Connect the trigger output T1, to gate and Cathode of SCR T1.

3. Switch on the DC supply to the power circuit and observe the voltage wave forms

across load by varying the frequency potentiometer.

Class C:- 1 .Make the connections on the power circuit as shown in the circuit diagram.

2. Connect the trigger outputs TI & T2 to the gate and cathode of SCR TI & SCR T2 respectively.

3. Switch on the DC supply to the power circuit and observe the voltage wave forms across RI, RI

and C by varying the frequency and also duty cycle potentiometer.

Class D:- l .Make the connections on the power circuit as shown in the circuit diagram.

2. Connect the trigger outputs T1 & T2,: to the gate and cathode of SCRT1 & SCRT2

respectively.

3.Observe the wave forms across load, C by varying frequency and also duty cycle

Model waveforms:-

Class: C Commutation

Class D Commutation

Precautions:-




Result:-

Review questions:-

1 .What is the difference between self and natural commutation?

2. What is principle of self commutation?

3. what are the differences between Voltage and current commutation?

4. what is the purpose of commutation circuit?

5. Why should be the reverse bias time greater than the turn-off time of an SCR?

6. How the voltage of commutation capacitor is reversed in a commutation circuit?

Exp. No.:

Date :

6. DC JONE’S CHOPPER WITH R & RL LOADS

Aim: - To observe the load voltage wave forms of JONE’S CHOPPER with R and RL load

Apparatus:-

Sl. No Item Type / Range Quantity

1. Jones Chopper power

circuit

SCR 1200V/ 25A, Diode

1200V/ 25A

1 1No

2. Jones Chopper firing

circuit

11 No

3. Regulated Power supply, 330 volts@ 2Amps 11 No

4. Inductive load 150mh/2A 11 No

5. Connecting wires Few

6. Load resistance. 550 Ohms, 5Amp 11 No

7 CRO 30MHz 11 No

Theory:-

In many industrial applications, it is required to convert a fixed – voltage dc Source in to a

variable voltage dc source. A dc chopper converts directly fixed dc to variable dc and is known as dc-to-

dc converter. A chopper can be considered as dc equivalent to an ac transformer with a continuously

variable turns ratio. Like a transformer, it can be used for step-up or step-down a dc voltage. Basic Power

circuit is shown in the figure. This chopper circuit is an example of class D commutation or Auxiliary

commutation. In this circuit SCR T1 is the main thyristor, where as SCR T2, capacitor C, D1 and Inductor

forms the commutating circuit for the main thyristor T1 .

Initially capacitor C is charged to a voltage EDC with the polarity shown. When SCR T1 is triggered,

current flows through the path CA-T1-L1-D1-CBand capacitor C charges to opposite polarity, i.e. plate B

positive and plate A negative .However, diode D1 Prevents further oscillation of the resonating L2C

circuit .Hence it retains its charge until SCR T2 is triggered. When SCR T2 is triggered, current flows

through the path CB-T2-T1-CA. Therefore discharge of capacitor C reverse biases SCRT1 and turns it off.

The capacitor again charges up with plate A positive and SCR T2 turns off because the current through it

falls below holding current value when capacitor C is charged to +EDC . The cycle repeats when SCR T1 is

triggered.

Circuit diagram:-

Procedure:-

1. Switch ON the main supply to DC- chopper firing unit.

2. Observe the test points and trigger outputs T m (T1) & Ta (T2)on the oscilloscope and their phase

sequence by varying duty cycle and frequency.

3. Make the interconnections in the power circuit as given in the circuit diagram.

4. Connect the triggering pulses from firing circuit to gate & cathode of main and auxiliary SCR`s in

the power circuit. Connect DC supply to DC input terminals in the power circuit.

5. Initially keep the ON / OFF switch for main thyristor pulse to OFF position.

6. Switch on the input supply in the power circuit. Now switch on the triggering pulses to the

chopper circuit and see that control switch is in ‘INT’ position.

7. ( Inreternal triggering Mode )

8. Set the duty ratio to a certain value and note down the load voltage by using multimeter and

also observe the load voltage waveform.

9. If the commutation fails (i.e. load voltage is same as input voltage) switch OFF the DC supply and

keep triggering pulses to OFF position and try again.

10. Repeat the step 7, for different duty ratios and frequencies.

11. Compare the theoretical and practical load voltages.

12. Also plot the duty cycle Vs load voltage curve.

Observations:- Input voltage=

Sample Calculations:- Eo = Edc * Ton / T

Model waveforms:-

Precautions:-

1) Ensure that connections are given properly before switching on power supply.

S.No Duty ratio Load voltage

Theoretical Practical


3) The student must wear leather chapels or shoes in the laboratory.


Result:-

Review Questions:-

1. What is a DC Chopper?

2. What is frequency modulation control of a chopper?

3. What is pulse-width modulation control of a chopper?

4. What is the purpose of diode in the commutation circuit of Jones Chopper?

5. What are the applications of a chopper?

6. What is the purpose of a commutation circuit in a chopper?

7. What is difference between the circuit turn off and turn-off time of a thyristor?

8. What are the advantages and disadvantages of variable frequency chopper?

9. What is the type of commutation used in Jones Chopper?

10. What is the principle of operation of step down and step up chopper?

Exp. No.:

Date :

7. SINGLE PHASE PARALLEL INVERTER

WITH R AND RL LOADS

Aim:- To study the principle of operation of single Phase parallel inverter with R and RL-Loads and

Observe the variation in the load voltage .

Apparatus:-

Sl. No Item Type / Range Quantity

1. Parallel inverter power

circuit

SCR 600V/16A 1No

2. Regulated Power supply, 30 volts@ 2Amps 1No

3. C.R.O. with 1:1Probe, 20MHz 1No

4. Load resistance. 100 Ohms, 2Amp 1No

5 Inductance 150 mh 1 No

Theory:-

This circuit is typical class ‘C’ Parallel Inverter . Assume TN to be ON and Tp to be OFF. The lower end

of the commutating capacitor is charged to twice the supply voltage and remains at this value until

Tp is turned on. When Tp is turned on, The current flows through lower half of the primary, Tp and

commutation inductance (L), Since the voltage across C cannot be instantaneous, the common SCR

cathode point raises approximately to 2V dc and reverse biases TN. Thus TN turns off and C

discharges through L, the supply circuit and then recharges in the reverse direction. The

autotransformer action makes C to charge making now its upper point to reach +2V dc volts ready to

commutate Tp, when TN is again turned on and the cycle repeats. The major purpose of

commutation inductor (L) is to limit commutation capacitor charging current during switching.

Free wheeling diodes Dp and DN assist the inverter in handling a wide range of loads and the value of

C may be reduced since the capacitor now does not have to carry the reactive current. To dampen

the feedback diode currents with in the half period, feed back diodes are connected to tapping of

the transformer of 25V.

Circuit Diagram:-

Procedure:-

1.Make the connections as shown in the circuit diagram .

2.Connect the load between load terminals

3 To begin with set the input voltage to 15 volts, apply trigger pulses to SCR and

4 observe voltage wave forms across load .Output voltage is square wave only.

5. Then vary the load, vary the frequency and observe the wave forms

Model Waveforms:-

Precautions:-

1. To switch OFF the inverter switch off DC input supply only. Switching off of the

trigger pulses will lead to short circuit.

2. Ensure that connections are given properly before switching on the power supply.


4. One must be aware of first-Aid techniques for electric-shock

Result:-

Review Questions:-

1.What type of commutation is used in parallel Inverter ?

2. Why the name parallel ?

3. What is the shape of the output voltage wave form of Parallel Inverter? Why it is so?

4.What is the minimum and maximum frequency of output voltage in this parallel inverter?

Exp. No.:

Date :

8. SINGLE PHASE CYCLO-CONVERTER WITH R & RL LOADS

Aim:- To study the output voltage wave forms of a Single Phase Cyclo-Converter with R and RL loads

Apparatus:-

S.No Item Type & Range Quantity

1. l - cyclo-converter power circuit

SCR 600V/12A 1 No

2. 1 - cyclo-converter firing

unit

--- 1NO

3. Isolation transformer 230V/30V-0-30V 1 NO

4. Resistive load 5 0 o hm / 5A 1 NO

5. Inductive load 0-150mh/2A 1 NO

6. Patch Cards Adequate

7 CRO 20MHz 1 NO

Theory:-

A device which converts input power at one frequency to output power at different frequency

with one-stage conversion is called a cyclo converter. A cyclo-converter is thus a one-stage frequency

changer. Basically, cyclo converters are two types (i) Step-down cycloconverter and (ii) step-up cyclo

converter. In step down cyclo converters, the output frequency fo is lower than the supply frequency fs,

i.e. fo<fs .Where as in step-up cycloconverter, fo>fs.The applications of cyclo-converters include the

following:

(i) Speed control of high power ac drives

(ii) Induction heating

(iii) Static VAR Generation

(iv) For converting variable speed alternator voltage to constant frequency output voltage for

use as power supply in air craft’s or ship boards.

The general use of cyclo-converter is to provide either a variable frequency power from a fixed

input frequency power (as in ac motor speed control) or a fixed frequency power from a variable input

frequency power (as in air craft or ship board power supplies).

Circuit diagram:-

Fig.(1)

Procedure:-

1. Connect the circuit diagram as shown above.

2. Check the Triggering pulses and connect to power circuit.

3. Switch on the firing kit and Switch on the MCB of power circuit to give power through

center tap transformer .

4. By varying the firing angle observe the wave-forms across R-Load .

5. Repeat 3 & 4 for different frequency divisions .

6. Repeat Steps 3 to 5 for inductive load in-series with R-load.

7. Note down the load voltage and currents for different firing angles for both R and RL

Loads.

Note:- If the output shows zero even after making the connections properly, switch off the input supply

and inter change the input supply. This is to make the input supply to the firing unit and the power

circuit in the same phase. If they are just opposite in phase, none of the SCRs will trigger and output will

be zero.

Observations:-

Model Wave forms:-

Precautions:-

S.No Input voltage, Vin Firing Angle Load voltage VL


2) The readings must be noticed care fully without parallax error.


4) ) Always change the frequency division only after switching off the trigger output

Result:-

Review Questions:-

1.Explain working principle of cyclo-converter?

2.What type of commutation is used in cyclo-converter?

3.What happens to the out put if the frequency of operation is beyond suggested limit?

4. What is the major difference between an AC voltage controller and a cyclo-converter?

Exp. No.:

Date :

9. SINGLE PHASE HALF-CONTROLLED BRIDGE CONVERTER

WITH R & RL LOAD

Aim:- To study the operation of a single phase half controlled converter with R and RL load.

Apparatus:-

s. no Item Type & Range Quantity

1.

l- Half-Controlled

converter power circuit

SCR 600V/ 16A, Diode

IN4007

1N o

2. 1 - converter firing unit --- 1 No

Theory:-

A 1-phase Half-controlled converter is a one quadrant converter and it has one polarity of

output voltage and current. During positive half cycle, SCR T1 is forward biased. When SCR T1 is fired at

ωt = α, the load is connected to the supply through T1and D2 during the period α < ωt < п. With

resistive load T1will conduct up to ωt = п and after that T1 is turned off due to natural commutation.

During negative half cycle of ac input, SCR T2 is forward biased and if it is triggered at ωt = п + α ,

current flows through the load till ωt=2п and the same process repeats for successive cycles.

In case of inductive load with freewheeling diode connected across load, when SCR T1 is

fired at ωt = α, the load is connected to the supply through T1 and D2 during the period α < ωt < п

3. Isolation transformer 230V/30V

1 No

4. Resistive load 50Ohm/5A 1 No

5. Inductive load 0-150mH/2A 1 No

6. Patch Cards Adequate

7 CRO 20 MHz 1 No

During the period п < ωt < (п + α), the input voltage is negative and freewheeling diode DF is forward

biased. DF conducts to provide the continuity of current in the inductive load. The load current is

transferred from TI & D2 to DF and TI & D2 are turned off. During negative half cycle of input voltage, SCR T2

is Forward biased and firing of T2 at ωt = п + α will reverse bias DF. DF is turned off and load is connected

to supply through T2 & D1.

Circuit diagram:-

Procedure:-

1. Make the connections as shown in circuit diagram.

2. Apply a voltage to the circuit through isolation transformer.

3. Switch on the triggering circuit.

4. Observe the load voltage wave form using C.R.O.

5. Now connect the freewheeling diode in the circuit and Note down the load voltage.

6. Repeat steps 4 & 5 for different triggering angles.

Observations:-

S..No Input voltage, Vin Firing Angle Load voltage VL

Sample Calculations:-

The average output can be found from )(2

2wtSinwtdVmVo

= Vm (1+cos α) / п

I0 = Vo/R

Model waveforms:-

Precautions:-

1. Don't touch the rectifier output terminals when the power card of the power circuit is

inserted in.

2. Ensure that connections are given properly before switching on the power supply.


4. One must be aware of first-Aid techniques for electric-shock

Result:-

Review Questions:-

1. What are the advantages of semi converter over full converter?

2. What is the effect of freewheeling diode in Half-Controlled converter?

3. What is meant by one quadrant operation of converters?

4. Which converter gives two quadrant operations?

5. Sketch the load voltage and current wave forms for Semi- converter with RL load?

Exp. No.:

Date :

10. SIMULATION ON SINGLE PHASE AC VOLTAGE CONTROLLER AND

FULLY CONTROLLED BRIDGE CONVERTER WITH R & RL LOAD USING P-

SPICE

AIM:

To perform PSPICE simulation of the following converter circuits

a) Single phase AC voltage controller with R load

b) Single phase AC voltage controller with R-L load

c) Single phase AC voltage controller with R-L-E load

APPARATUS:

PSPICE software

CIRCUIT DIAGRAM FOR R LOAD:

SUBCIRCUIT:

PROGRAM FOR R LOAD:

SINGLE PHASE AC VOLTAGE CONTROLLER WITH R LOAD

VS 1 0 SIN(0 169.7 50)

VG1 2 4 PULSE(0 10 1666.67US 1NS 1NS 100US 20MS)


R 4 5 2OHM

VX 5 0 DC 0V

CS 1 6 0.1UF

RS 6 5 750OHM

XT1 1 4 2 4 SCR

XT2 4 1 3 1 SCR

.SUBCKT SCR 1 2 3 2

S1 1 5 6 2 SMOD

RG 3 4 50OHM

VX 4 2 DC 0V

VY 5 2 DC 0V

RT 2 6 1OHM

CT 6 2 10UF

F1 2 6 POLY(2) VX VY 0 50 11

.MODEL SMOD VSWITCH(RON=0.0125 ROFF=10E+5 VON=0.1V VOFF=0V)

.ENDS SCR

.TRAN 1US 60MS

.PROBE

.END

CIRCUIT DIAGRAM FOR R-L LOAD:

SUB CIRCUIT:

PROGRAM FOR R-L LOAD:

SINGLE PHASE AC VOLTAGE CONTROLLER WITH R-L LOAD

VS 1 0 SIN(0 169.7 50)



R 4 5 30OHM

L 5 6 35MH

VX 6 0 DC 0V

CS 1 7 0.1UF

RS 7 4 750OHM

XT1 1 4 2 4 SCR

XT2 4 1 3 1 SCR

.SUBCKT SCR 1 2 3 2

S1 1 5 6 2 SMOD

RG 3 4 50OHM

VX 4 2 DC 0V

VY 5 2 DC 0V

RT 2 6 1OHM

CT 6 2 10UF

F1 2 6 POLY(2) VX VY 0 50 11


.ENDS SCR

.TRAN 1US 60MS

.PROBE

.END

RESULT FOR R LOAD:

RESULT FOR R-L LOAD:

Exp. No.:

Date :

11. PSPICE SIMULATION OF SINGLE PHASE FULL CONVERTER CIRCUITS

AIM:

To perform PSPICE simulation on the following converter circuits.

a) Single phase full converter with R load b) Single phase full converter with R-L load c) Single phase full converter with R-L-E load

APPARATUS:

PSPICE software

CIRCUIT DIAGRAM FOR R LOAD:

SUB CIRCUIT:

PROGRAM FOR R LOAD:

SINGLE PHASE FULL CONVERTER WITH R LOAD

VS 1 2 SIN(0 169.7 50)





XT1 1 7 3 7 SCR

XT2 0 2 6 2 SCR

XT3 2 7 4 7 SCR

XT4 0 1 5 1 SCR

R 7 0 10OHM

.SUBCKT SCR 1 2 3 2

S1 1 5 6 2 SMOD

RG 3 4 50OHM

VX 4 2 DC 0V

VY 5 7 DC 0V

DT 7 2 DMOD

RT 6 2 1OHM

CT 6 2 10UF

F1 2 6 POLY(2) VX VY 0 50 11

.MODEL SMOD VSWITCH (RON=0.0125 ROFF=10E+5 VON=0.5V VOFF=0V)

.MODEL DMOD D(IS=2.2F-15 BV=1800V TT=0)

.ENDS SCR

.TRAN 1US 60MS

.PROBE

.END

CIRCUIT DIAGRAM FOR R-L LOAD:

SUB CIRCUIT:

PROGRAM FOR R-L LOAD:

SINGLE PHASE FULL CONVERTER WITH R-L LOAD

VS 1 2 SIN(0 169.7 50)





XT1 1 7 3 7 SCR

XT2 0 2 6 2 SCR

XT3 2 7 4 7 SCR

XT4 0 1 5 1 SCR

R 7 8 10OHM

L 8 0 10MH

.SUBCKT SCR 1 2 3 2

S1 1 5 6 2 SMOD

RG 3 4 50OHM

VX 4 2 DC 0V

VY 5 7 DC 0V

DT 7 2 DMOD

RT 6 2 1OHM

CT 6 2 10UF

F1 2 6 POLY(2) VX VY 0 50 11



.ENDS SCR

.TRAN 1US 60MS

.PROBE

.END

CIRCUIT DIAGRAM FOR R-L-E LOAD:

SUB CIRCUIT:

PROGRAM FOR R-L-E LOAD:

SINGLE PHASEFULL CONVERTER WITH RLE-LOAD

VS 1 2 SIN(0 169.7 50)





XT1 1 7 3 7 SCR

XT2 0 2 6 2 SCR

XT3 2 7 4 7 SCR

XT4 0 1 5 1 SCR

R 7 8 10OHM

L 8 9 10MH

VE 9 0 DC 5V

.SUBCKT SCR 1 2 3 2

S1 1 5 6 2 SMOD

RG 3 4 50OHM

VX 4 2 DC 0V

VY 5 7 DC 0V

DT 7 2 DMOD

RT 6 2 1OHM

CT 6 2 10UF

F1 2 6 POLY(2) VX VY 0 50 11



.ENDS SCR

.TRAN 1US 60MS

.PROBE

.END

RESULT FOR R LOAD:

RESULT FOR R-L LOAD:

RESULT FOR R-L-E LOAD:

Exp. No.:

Date :

12.SIMULATION ON RESONANT PULSE COMMUTATION CIRCUIT USING

P-SPICE AIM:

To perform PSPICE simulation on Resonant pulse commutation circuit.

APPARATUS:

PSPICE software.

CIRCUIT DIAGRAM:

SUB CIRCUIT:

PROGRAM:

RESONANT PULSE COMMUTATION

VS 1 0 DC 200V

VG1 7 4 PULSE(0 10 0.0MS 1NS 1NS 0.4MS 1MS)



D1 4 1 DMOD

DF 0 4 DMOD

.MODEL DMOD D(IS=2.2E-15 BV=1200V TT=0 CJO=0)

C 1 2 31.2UF IC=200V

XT1 10 4 7 4 SCR

XT2 3 4 8 4 SCR

XT3 1 3 9 3 SCR

VX 6 0 DC 0V

VY 1 10 DC 0V

L1 2 3 6.4MH

L2 5 6 5MH

R 4 5 1.0OHM

.SUBCKT SCR 1 2 3 4

S1 1 5 3 4 SMOD

DT 5 2 DMOD

.MODEL SMOD VSWITCH(RON=0.01 ROFF=10E+6 VON=10V VOFF=0V)

.MODEL DMOD D(IS=2.2E-15 BV=1200V TT=0 CJO=0)

.ENDS SCR

.TRAN 1US 6MS

.PROBE

.END

RESULT:

Exp. No.:

Date :

13. PSPICE SIMULATION ON THREE PHASE FULL CONVERTER

AIM:

To perform PSPICE simulation on three phase full converter.

APPARATUS:

PSPICE software.

CIRCUIT DIAGRAM:

SUB CIRCUIT:

PROGRAM:

THREE PHASE FULL CONVERTER

VAN 14 0 SIN(0 325V 50HZ 0 0 0DEG)

VBN 6 0 SIN(0 325 50HZ 0 0 -120DEG)

VCN 7 0 SIN(0 325 50HZ 0 0 -240DEG)

VG1 8 2 PULSE(0 10V 5000US 1NS 1NS 100US 20000US)

VG2 13 7 PULSE(0 10V 8333.3US 1NS 1NS 100US 20000US)





R 2 4 0.5OHM

L 4 5 0.5MH

VY 5 3 DC 0V

VX 14 1 DC 0V

XT1 1 2 8 2 SCR

XT2 3 7 13 7 SCR

XT3 6 2 9 2 SCR

XT4 3 1 11 1 SCR

XT5 7 2 10 2 SCR

XT6 3 6 12 6 SCR

.SUBCKT SCR 1 2 3 2

RG 3 4 50

VX 4 2 DC 0V

S1 1 5 6 2 SMOD

VY 5 7 DC 0V

DT 7 2 DMOD

RT 6 2 1OHM

CT 6 2 10UF

F1 2 6 POLY(2) VX VY 0 50 11


.MODEL DMOD D(IS=100E-15 BV=1200V TT=0)

.ENDS SCR

.TRAN 50US 100MS 50MS 50US

.PROBE

.END

RESULT:

Exp. No.:

Date :

14 . SINGLE PHASE DUAL CONVERTER

AIM: To study the dual converter with R & RL load.

APPARATUS REQUIRED:

S.No. Name of the equipment Range Qty

01 Single phase dual converter.(power circuit

& firing circuit.)

- 01

02 Patch chords & Probes - Adequate

03 CRO - 01

04 Isolation transformer(With tappings) - 01

05 R load 0-200 ohm / 5A 01

06 L load(center tapped) 300-0-300mH/5A 01

CIRCUIT DIAGRAM:

NON- CIRCULATING CURRENT MODE:

CIRCULATING CURRENT MODE:

PROCEDURE:

NON- CIRCULATING CURRENT MODE:

1. Make all connections as per the non circulatory circuit diagram.

2. Connect R-load across load terminals.

3. Connect the input AC supply to the power circuit through an Isolating Transformer(take

input voltage 30V)

4. Select the NCC mode in firing circuit.

5. Give the firing pulses and keep P-converter in ON position and also put on the MCB switch.

6. By varying the firing angle observe related out put waveforms in the CRO.Tabulate all the

readings.

7. Repeat all above procedure for RL-load.

CIRCULATING CURRENT MODE:

1. Make all connections as per the circulatory circuit diagram.

2. Connect R-load across load terminals.

3. Connect the input AC supply to the power circuit through an Isolating Transformer(take

input voltage 30V)

4. Select the CC mode in firing circuit.

5. Give the firing pulses and keep P-converter in ON position and also put on the MCB switch.

6. By varying the firing angle observe related out put waveforms in the CRO.Tabulate all the

readings.

7. Repeat all above procedure for RL-load.

TABULAR COLUMN:

S.No. Input Voltage (V

in)

Firing angle

in Degrees

Output voltage (V0) Output Current (I0)

Theoretical Practical Theoretical Practical

MODULE CALCULATIONS:

V0 = (2√2V / ∏) * (Cos )

I0 = (2√2V / ∏Z) * (Cos )

= Firing Angle

V = RMS Value across transformer output

MODEL GRAPH:

RESULT: The single phase dual converter with R & RL load is studied.

department of electrical and electronics engineering lab... · 2019. 2. 6. · 10 simulation on...

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