Power Electronics and Drives (PCEET403) Syllabus

Role of power electronics, motivation, objectives and challenges, power electronics vs. linear electronics, ideal and real switches, static and dynamic performance, power losses, temperature rise, thermal analogy, use of heat sinks. Uncontrolled switch: power diodes — types, characteristics, effects of reverse recovery transient, ratings, Schottky diodes. Semi-controlled switch: SCR (thyristor) — symbol, structure, characteristics, turn-on and turn-off phenomena, ratings, gate control, gate drive circuits, gate synchronisation, isolated gate drives. Fully-controlled switches: MOSFETs and IGBTs — symbol, structure, characteristics, device ratings, gate drive requirements. Modern power devices — introduction to wide bandgap devices (SiC MOSFET and GaN HEMT).

Controlled rectifiers (single phase) — fully controlled and half-controlled rectifiers (semi-converter) with RL and RLE loads, rectifier and inverter modes of operation, waveforms, output voltage, input line current, real power, power factor and THD, effect of source inductance. Controlled rectifiers (3-phase) — fully controlled and half-controlled bridge converter with RLE load, waveforms, output voltage equation. AC voltage controllers — 1-phase full-wave ACVC with R and RL loads, waveforms, RMS output voltage, applications. DC-DC switching regulators — Buck, Boost and Buck-Boost converters, operation with continuous conduction waveforms, effect of non-idealities, design of filter inductance and capacitance, selection of power devices.

Switch mode DC-AC voltage source inverters (VSI) — single phase half-bridge and full-bridge configurations, sinusoidal PWM, control of fundamental output voltage, harmonic spectrum, bipolar and unipolar PWM, linear/over modulation/square wave modes, need for blanking time. Three-phase PWM VSI — fundamental output voltage, linear/over modulation/square wave modes, third harmonic injection PWM. Single phase current regulated VSI — tolerance band current control, fixed frequency operation, single phase current source inverters. Need for improved utility interface — generation of current harmonics, power factor, harmonics and IEEE 519 standard, active shaping of the input line current, single-phase front end boost converter.

Introduction to electric drives — advantages of adjustable speed electric drives, block diagram, types of loads, classification of load torque, motor torque-load combination, steady state stability. DC drives — chopper control of separately excited DC drives (one/two/four quadrant, continuous conduction only), motoring and regenerative braking, speed-torque characteristics, speed control, controlled rectifier fed separately excited DC motor drive (single and three phase), dual converter drives. Three-phase VSI fed induction motor drives — stator voltage control, V/F speed control, speed-torque characteristics, speed control above and below base speed, braking (dynamic and regenerative).