Theory Portion:
UNIT I Commutation Circuits and Phase Controlled Rectifiers Period
Power Electronics: Definition – Scope and Applications – Power Electronic Switch
Specifications – Types of Power Electronic Circuits.
7
SCR – rating and their importance, Symbol, Circuit, Working, Characteristics and
Applications – Line Synchronized UJT Triggering Circuits – Working, Characteristics
and Applications of IGBT and MOSFET.
Commutation Circuits: SCR Turn Off Methods – Natural Commutation – Forced
commutation – Class A, Class B, Class C, Class D, Class E and Class F.
Phase Controlled Rectifiers: Introduction – Phase Controlled Rectifiers – Single
Phase Fully Controlled Bridge with R Load, RL Load – Single Phase Dual Converter
– Three Phase Fully Controlled Bridge with RL Load – Introduction to Single Phase
Cycle Converter with Simple Circuit.
Practical Exercises:
Ex.No Name of the Experiment Period
1. Construct the Line synchronized Ramp trigger circuit using UJT with
AC Load to measure firing angles.
6
2. Construct and test the SCR commutation circuits. 6
3. Construct and test a Half wave controlled rectifier with R Load. 6
4. Construct and test a single phase fully controlled bridge rectifier with
RL-Load.
6
5. Construct and test the single phase to single phase Cyclo converter. 6
Theory Portion:
UNIT II Converters and Applications of Power Electrons Period
Choppers: Introduction, Principle of Chopper Operation, Control Strategies –
Constant Frequency System and Variable Frequency System – Circuit Diagram and
Working – Step Up Chopper – Four Quadrant Choppers.
8
(iv)
Inverters: Introduction, Classification of Inverter. Circuit Diagram, Working and
Waveform – Full Bridger Inverter – Three Phase Bridge Inverter Under 180° Mode
and 120° Mode Operations – Pulse Width Modulated Inverters, (Single Pulse,
Multiple Pulse, Sinusoidal Pulse).
DC Drives: Basic DC Motor Speed Equation – Circuit Diagram, Output Waveforms
and Output Equation of – Separately Excited DC Motor – Single Phase Full
Converter Drives.
AC Drives: Speed Control by Rotor Resistance for Slip Ring Induction Motors –
Static Scherbius Drive (Slip Power Recovery Scheme) – Variable voltage and
Variable frequency drive – Block diagram.
Practical Exercise:
Ex.No Name of the Experiment Period
6. Design the PWM based step down DC Chopper using MOSFET/IGBT. 6
7. Construct and test the Single phase Single pulse / Sinusoidal PWM
inverter using MOSFET/IGBT.
6
8. Construct and test the ON / OFF control of Lamp using solid state Relay. 6
9. Construct and test the Speed Control of AC Motor using VFD drive. 6
10. Construct a Lamp dimmer circuit using TRIAC. 6
Total Periods 75