Unit 1 Power switching devices

6 lecture hours

• Static characteristics of these devices
• Operation of power devices as switches and switching losses
• Single-quadrant switches
• two-quadrant and bidirectional switches
• Firing circuit for thyristors
• Gate drive circuits for MOSFET and IGBT

Unit 2 DC-DC converters - Switching Voltage Regulators

12 lecture hours

• Linear voltage regulator
• Concept of switching voltage regulators and advantages
• Operation and Principle of Basic DC-DC converter topologies like Buck
• Boost and Buck- Boost converter
• Various control techniques for output voltage control
• Mathematical analysis for these converters for steady state
• Concept of CCM and DCM and factors affecting them
• Closed loop control for voltage regulation
• Isolated converters: Forward converter and Flyback converter
• Multi-quadrant operation of DC-DC converters

Unit 3 DC-AC converters – Inverters

12 lecture hours

• Classification of Inverters
• Half-bridge and full-bridge single-phase voltage source inverter
• switch states and instantaneous output voltage
• square wave operation of the inverter
• concept of average voltage over a switching cycle
• bipolar sinusoidal modulation and unipolar sinusoidal modulation
• modulation index and output voltage
• three-phase sinusoidal modulation
• Three phase bridge inverter – 180◦ and 120◦ conduction mode
• SPWM control
• Third harmonic injection
• Output voltage and frequency control
• Harmonic spectrum
• Harmonics and its effects

Unit 4 AC-DC Converters

• Concept of phase control using half-wave single phase ac-dc converter
• Single phase and 11 Subject Code: 3140915 w.e.f
• AY 2018-19 three phase half wave and full wave
• 1-phase and 3- phase half controlled and fully controlled converters
• Analysis with R & RL load
• Performance parameters for converters
• Operation in continuous and dis-continuous mode
• Reactive power considerations
• Operation in conversion and inversion mode
• Effect of source inductance
• Power factor improvement techniques
• Dual Converters

Unit 5 AC Voltage Controller

7 lecture hours

• Triac characteristic and operating modes
• Triac as Single-phase AC voltage controller
• Principle of Phase Control
• On-off Control
• Mathematical analysis related to single-phase AC voltage controller
• Three-phase AC voltage controller configurations: Operations

Unit 6 Miscellaneous

7 lecture hours

• Frequency Control: Introduction to cycloconverter and matrix converter
• basic power circuit and their operating principle (2 Hrs) Datasheet interpretation
• Ratings of the devices and Selection of switches (2 Hrs) Overvoltage
• overcurrent and short-circuit protection
• Electromagnetic interference and its remedies
• Snubber circuit and its design (3 Hrs)