UNIT–I POWER SEMI CONDUCTOR DEVICES

1.1 Thyristors – Silicon controlled rectifiers (SCR’s) – Characteristics of power MOSFET and power IGBT

1.2 Basic theory of operation of SCR – Static characteristics Turn on and turn off methods – Dynamic characteristics of SCR

1.3 Snubber circuit design – Numerical problems

1.4 Diode bridge rectifier with R–load and capacitive filter – Output voltage and input current waveforms.

UNIT–II PHASE CONTROLLED CONVERTERS – SINGLE PHASE

2.1 Firing circuits for SCR

2.2 Line commutation principle

2.3 Single phase AC voltage controller with R and RL load

2.4 Half wave converters with R,RL and RLE loads – Derivation of average load voltage and current – Effect of freewheeling diode for RL load

UNIT–III SINGLE PHASE BRIDGE CONVERTER AND HARMONIC ANALYSIS FULLY CONTROLLED CONVERTERS

3.1 Operation with R, RL and RLE loads–Derivation of average voltage and current

3.2 Effect of source Inductance. Semi Converters (Half Controlled): Operation with R, RL and RLE loads

3.3 Harmonic analysis for input current waveform in a system with a large load inductance – Calculation of input power factor

UNIT–IV THREE PHASE AC–DC BRIDGE CONVERTERS

4.1 Full converter with R and RL loads

4.2 Semi converter (Half Controlled) with R and RL loads – Derivation of load voltage

4.3 Line commutated Inverter operation – Dual converters with non–circulating and circulating currents

UNIT – V AC–AC AND DC–DC CONVERTERS

5.1 Single phase Bridge type cyclo converter with R and RL load (Principle of operation)

5.2 High frequency DC– DC converters:Buck Converter operation – Time ratio control and current limit control strategies – Voltage and current waveforms – Derivation of output voltage

5.3 Boost converter operation – Voltage and current waveforms – Derivation of output voltage

5.4 Buck-Boost converter operation – Voltage and current waveforms.

UNIT – VI DC–AC INVERTERS

6.1 Inverters Single phase inverters – Unipolar and bipolar switching

6.2 Three phase Inverters (120⁰ and 180⁰ modes of operation)

6.3 PWM techniques – Sine triangular PWM technique - Amplitude and frequency modulation Indices – Harmonic analysis