Power Electronics

SYLLABUS:

UNIT – I
POWER SEMI CONDUCTOR DEVICES
Introduction – Thyristors, Silicon Controlled Rectifiers (SCR‘s) ,BJT, Power MOSFET,
Power IGBT and their characteristics and other thyristors, Basic theory of operation of SCR,
Static characteristics, Turn on and turn off methods, Dynamic characteristics of SCR,
COMMUTATION CIRCUITS
Turn on and Turn off times ,Salient points – Two transistor analogy , SCR, R and RC
Triggering , UJT firing circuit, Series and parallel connections of SCR‘s, Snubber circuit
details, Specifications and Ratings of SCR‘s, BJT, IGBT, Numerical problems, Line
Commutation and Forced Commutation circuits.
UNIT-2
SINGLE PHASE :HALF CONTROLLED CONVERTERS
Phase control technique – Single phase Line commutated converters, Midpoint and Bridge
connections, Half controlled converters with Resistive, RL loads and RLE load,
FULL CONTROLLED CONVERTERS
Full controlled converters with, Resistive, RL loads -Derivation of average load voltage and
current -Active and Reactive power inputs to the converters without and with Freewheeling
Diode- Effect of source inductance, problems

UNIT – III
THREE PHASE LINE COMMUTATED CONVERTERS
Introduction to Three phase converters, Three pulse and six pulse converters , Mid point and
bridge connections average load voltage With R and RL loads, Effect of Source inductance,
Dual converters (both single phase and three phase), Waveforms ,Problems.

UNIT – IV
AC VOLTAGE CONTROLLERS
AC voltage controllers, Single phase two SCR‘s in anti parallel, With R and RL loads –
modes of operation of Triac, Triac with R and RL loads, Derivation of RMS load voltage,
current and power factor wave forms, Firing circuits, problems,
CYCLO CONVERTERS
Cyclo converters, Single phase midpoint cyclo converters with Resistive and inductive load –
Principle of operation, Bridge configuration of single phase cyclo converter-Principle of
operation, Waveforms.
UNIT – V
CHOPPERS
Choppers – Time ratio control and Current limit control strategies ,Step down choppers
Derivation of load voltage and currents with R, RL and motor loads- Step up Chopper –four
quadrant operation of dc drives,
INVERTERS
Inverters – Single phase inverter, Basic series inverter, Basic parallel Capacitor inverter
bridge inverter, Waveforms, Voltage control techniques for inverters Pulse width modulation
techniques, problems.

Materials for Power Electronics:

Textbook: View/Download

Unit-1 :View/Download

Unit-2 :View/Download

Unit-3: View/Download

Unit-4 : View/Download

Unit-5 :View/Download

Question Bank for Power Electronics:

unit 1,2 :View/Download

Unit-3,4,5: View/Download

Bit Bank:

Mid1:View/Download

Mid2:View/Download