Department of Technical Education
DIPLOMA COURSE IN ELECTRICAL AND ELECTRONICS ENGINEERING
Fourth Semester
Sub: POWER ELECTRONICS
Sub Code:
Contact Hrs/Week: 4 Contact Hrs/Sem: 64
Chapter No. Topic No. of Hours.
UNIT I
1 Power semiconductor devices 12
2 SCR controlled circuits 6
UNIT II
3 Controlled rectifiers 5
4 Choppers 2
5 Inverters 4
6 Cycloconverters 2
7 Device Protection 6
UNIT III
8 Power Supplies and Stabilizers 8
9 Switch Mode Converters 5
10 Power Electronics Applications 4
11 Industrial innovations 6
12 Tests and Revision 4
__________
TOTAL 64
CONTENT
1 Power Semiconductor Devices
2 Power Diode, SCR, TRIAC, DIAC, BJT, MOSFET, IGBT
2 SCR control circuits
a) Turn-on methods
b) Turn-off methods (Commutation)
3 Controlled Rectifiers (AC to DC Line commutated converters)
Principle of phase control
Single phase fully controlled bridge rectifier
Three phase fully controlled bridge rectifier
4 Chopper Step-down, Step-up choppers
5 Inverter Single phase half bridge, full bridge and three phase full bridge
6 Cycloconverters
7 Device Protection Rating, Specification and Nomenclature of SCRs
Protection of SCRs
Selection of SCRs
Reliability and failure mechanism of SCRs
8 Power Supplies Stabilizers
DC regulated supplies using IC (Linear Power Supplies)
Switched Mode Power Supplies(SMPS)
Power supplies for Battery charger
9 Switch Mode Converters
Flyback DC to DC converter.
Forward or buck or step down DC to DC converter.
Boost or step up DC to DC converter.
Buck- boost DC to DC converter.
10 Power Electronics Applications.
Speed control of separately excited DC motor by armature voltage control method.
Speed control of Induction Motor by Variable voltage -frequency method.
Optocoupler device construction.
Solid state relay SSR.
11 Industrial innovations
12 Tests and Revision
REFERENCES:
1. Power Electronics by K Shashidhar, Sapna Publications.
2. Power Electronics by Mohan, Undeland & Robbins –Wiley India.
3.Power Electronics By Umanand - Wiley India
GENERAL EDUCATIONAL OBJECTIVES:
1 Know the principle of operation, characteristics and applications of power
Semiconductor devices
2 Understand turn-on and turn-off methods for SCR.
3 Know the operation of controlled rectifier
4 Know the operation of chopper
5 Know the operation of inverter
6 Know the operation of cycloconverter.
7 Understand ratings, specifications, protection, selection and reliability of SCR.
8 Know the operation of power supplies, stabilizers.
SPECIFIC INSTRUCTIONAL OBJECTIVES
1 Power Semiconductor devices 12hrs
1.1 Power Diode
1.1.1 Explain V-I characteristic curve of power diode
1.1.2 List applications of power diode
1.2 SCR
1.2.1 Draw the layer diagram of SCR and explain the same
1.2.2 Explain the two transistor analogy of SCR(no derivation)
1.2.3 Explain the static V-I characteristic curve of SCR
1.2.4 List applications of SCR
1.3 TRIAC
1.3.1 Explain the operation of triac and draw its static V-I characteristic curve
1.3.2 List the modes of operation of triac and mention the preferred modes
1.3.3 List applications of triac
1.4 DIAC
1.4.1 Explain the operation of diac and draw its V-I characteristic curve
1.4.2 List applications of diac
1.5 BJT
1.5.1 Describe the operation of an NPN transistor as a switch
1.5.2 List the applications of BJT in power switching applications
1.6 MOSFET
1.6.1 Explain the operation of MOSFET and draw its transfer characteristic curve
1.6.2 List applications of MOSFET
1.7 IGBT
1.7.1 Explain the operation of IGBT and draw its V-I characteristics
1.7.2 List applications of IGBT
1.7.3 Compare IGBT,BJT and MOSFET
Reference book: Industrial Electronics and controls-Biswanath paul Page.No:298
Reference Books:
1 M Ramamoorthy
2 Clay Laster
3 Mohan and Rashid
2 SCR control circuits 6hrs
2.1 Describe briefly different methods of Turn-ON SCR
2.2 List two general functions to be fulfilled by gate control circuits
2.3 Draw the general layout diagram of firing circuit and explain.
2.4 Draw R firing circuit and explain .
2.5 Draw R-C firing circuit and explain.
2.6 Draw UJT pulse trigger circuit and explain.
2.7 Explain Digital firing circuit.
2.7 Define commutation
2.8 List different types of commutation
Ref: for 1.2 complete GK Dubey
3 Controlled Rectifiers 5hrs
3.1 Explain controlled rectifiers
3.2 Explain single quadrant semi converter, two quadrant full converter and dual converter
3.3 Explain line or natural commutation
3.4 Explain the principle of phase control and define firing angle (alpha) and conduction angle (beeta)
3.5 Explain with schematic diagram and waveforms, the operation of single phase half wave controlled converter.
3.6 Explain with schematic diagram and waveforms, the operation of single phase fully controlled bridge converter
3.7 Explain with circuit diagram and waveforms the operation of fully controlled three phase bridge Converter
Ref: Rashid
GK Dubey
M Ramamoorthy
4 Choppers 2hrs
4.1 Define chopper
4.2 Draw the basic power circuit (without commutation circuit) of a step down chopper and explain its operation with waveforms
4.3 Draw the basic power circuit (without commutation circuit) of a step up chopper and explain its operation with waveforms
Ref: GK Dubey
Dewan
5 Inverters 4hrs
5.1 Define Inverter.
5.2 Classify the inverters based on Source.
5.3 Define Voltage Source Inverter and Current Source Inverter.
5.4 Differentiate between Voltage Source Inverter and Current Source Inverter
5.5 Draw the schematic diagram of voltage source single phase half bridge inverter (without commutation circuit) and explain its operation
5.6 Draw the schematic diagram of voltage source single phase full bridge inverter (without commutation circuits) and explain its operation
5.7 Draw the schematic diagram of voltage source three phase bridge inverter (without commutation circuit) and explain its operation
Ref Ramamoorthy
Rashid
Industrial Electronics and controls-Biswanath paul
Page.No:340 and 341(For Sections 5.2,5.3 and 5.4)
6 Cycloconverters 2hrs
6.1 Define cycloconverter and mention its types (step up and step down)
6.2 State the advantages and disadvantages of cycloconverter
6.3 Draw the diagram of a single phase to single phase cycloconverter and explain
Ref Rashid
7 Device Protection 6hrs
7.1 Give specifications, ratings and nomenclature of Thyristors,
BJT, MOSFET and IGBT
7.2 Describe how SCR can be protected against overvoltage and overcurrent
7.3 Describe dv/dt and di/dt protection of SCR
7.4 Describe the process involved in selecting an SCR for a particular application
7.5 Define reliability of SCR and mean time between failures (MTBF)
7.6 Explain the three failures of an SCR (Mechanical, Electrical and Thermal)
7.7 Explain mounting of SCR with suitable heat sink.
Ref: Ramamoorthy
Rashid
Dubey
MD Singh, Clay Laster
8 Power Supplies, Stabilizers 8hrs
8.1 Draw a schematic diagram of switched mode power supply (SMPS) and explain its operation
8.2 Compare linear power supply with SMPS
8.3 List the applications of linear power supply and SMPS
8.4 Draw a schematic diagram of SCR battery charger and explain
8.5 Define online UPS system and offline UPS system
8.6 Draw a block diagram of UPS system and explain its operation
8.7 Determine Battery size and required voltage for UPS(Ref: Modern Power
Electronics by P.C.Sen Page No.832 and 833)
8.8 List the areas of applications of UPS system
8.9 Define the different types of power line disturbances such as overvoltage, black out voltage spike, chopped voltage, harmonics, Total Harmonics Distortion factor and EMI
8.10 List the sources of power line disturbances of mentioned in 8.9
8.11 Give the effect of power line disturbances on sensitive equipments such as computer
8.12 Describe how power conditioners provide effective suppressing of some or all of these electrical disturbances
8.13 Describe the operation of relay type AC voltage stabilizer with the help of diagram
8.14Draw the diagram of constant voltage transformer (CVT) type AC voltage
stabilizer and explain its operation
8.15 Draw the diagram of AC servo voltage stabilizer and explain its operation
Ref: Gayakwad
Mohan
Schuler and Mc Namee
Bradley
Harish C Rai
Chute & Chute
MC Sharma
Ramamoorthy
Whittington, Universities Press(India) Pvt. Ltd.
9 Switch Mode Converters 5hrs
9.1 Explain with circuit diagram Flyback DC to DC converter.
9.2 Explain with circuit diagram Forward or buck or step down DC to DC converter.
9.3 Explain with circuit diagram boost or step up DC to DC converter.
9.4 Explain with circuit diagram buck- boost DC to DC converter.
9.5 Compare buck, boost and buck-boost DC to DC converter.
Ref: Biswanath Paul PHI Publication Edition-II Page. No: 36 to 44
10 Power Electronics applications 4hrs
10.1 Explain speed control of shunt –wound DC motor by armature voltage control
method.
10.2 Explain speed control of Induction Motor by Variable voltage -frequency method.
Ref: Biswanath Paul PHI Publication Edition-II Page.No: 403 to 405,408 to 419
10.3 Give basic optocoupler device construction and explain
10.4 Circuit diagram of solid state relay SSR and explain
10.5 State the advantages of SSR over electromechanical relay and give its applications
11 Industrial innovation and seminars (Not for end examination) 6hrs
11.1 seminars by industrial experts/academic experts/visit to nearby industry
12 Tests and revision 4hrs
Total 64hrs
POWER ELECTRONICS
TENTATIVE CHAPTER WISE MARK DIVISION
| | | Hours | Approx Total marks for setting questions in the chapter |
| UNIT I | | | |
| 1 | Power semiconductor devices | 12 | 30 |
| 2 | SCR controlled circuits | 6 | 15 |
| | | | |
| | | | |
| UNIT II | | | |
| 3 | Controlled rectifiers | 5 | 15 |
| 4 | Choppers | 2 | 5 |
| 5 | Inverters | 4 | 10 |
| 6 | Cycloconverters | 2 | 5 |
| 7 | Device Protection | 6 | 15 |
| | | | |
| | | | |
| UNIT III | | | |
| 8 | Power Supplies and Stabilizers | 8 | 20 |
| 9 | Switch Mode Converters | 5 | 10 |
| 10 | Power Electronics Applications | 4 | 10 |
| | | | |
| 11 | Industrial innovations | 6 (Ex) | |
| 12 | Tests and Revision | 4 (Ex) | |
| | TOTAL | 54 | 135 |
There is a compulsory part of 10 marks in the beginning, out of which, 05 marks is for “Fill in the blanks” type questions.
