JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

Prerequisites

Power Electronics, AC and DC Machines, Control Systems

Course Objectives

• To understand the drive system and converter, chopper fed DC separately excited motor
• To understand principle operation of scalar control of ac motor and corresponding speed- torque-slip characteristics
• To comprehend the vector control for ac motor drive (IM and SM)
• To explain the static resistance control and Slip power recovery drive
• To explain synchronous motor drive characteristics and its control strategies
• To comprehend the brushless dc motor principle of operation.

Course Outcomes

Upon the completion of the course the student will be able to

• Analyze drive characteristics and converter as well chopper fed dc drives
• Develop induction motor for variable speed operations using scalar and vector control techniques.
• Identify the difference between the rotor resistance control and static rotor resistance control method and significance of slip power recovery drives
• Develop Controllers for synchronous motor and variable reluctance motor can be developed

UNIT - I

Introduction to drive systems: Basic power electronic drive system, components - Different types of loads, shaft-load coupling systems - Stability of power electronic drive. DC Motor Speed Control: Three Phase full converter fed separately excited motor for one, two and four quadrant applications for speed control, closed loop operation; dc chopper controlled separately excited motor for one, two and four quadrant application for speed control of closed loop operation

UNIT - II

Stator Side Control of Induction Drives: Scalar control – Voltage fed inverter control – Open loop volts/Hz control – speed control slip regulation – speed control with torque and flux control – current controlled voltage fed inverter drive – current – fed inverter control – Independent current and frequency control – Speed and flux control in Current –Fed inverter drive – Volts/Hz control of Current –fed inverter drive – Efficiency optimization control by flux program.

UNIT - III

Rotor Side Control of Induction Drives: Slip power recovery drives – Static Kramer Drive – Phasor diagram – Torque expression – speed control of Kramer Drive – Static Scheribus Drive – modes of operation. Vector control of Induction Motor Drives: Principles of Vector control – Vector control methods – Direct methods of vector control – Indirect methods of vector control

UNIT - IV

Control of Synchronous Motor Drives: Synchronous motor and its characteristics – Control strategies – Constant torque angle control – Unity power factor control – Constant mutual flux linkage control.

Controllers: Flux weakening operation – Maximum speed – Direct flux weakening algorithm – Constant Torque mode controller – Flux Weakening controller – indirect flux weakening – Maximum permissible torque – speed control scheme – Implementation strategy speed controller design.

UNIT - V

Variable Reluctance Motor Drive: Variable Reluctance motor drive – Torque production in the variable reluctance motor Drive characteristics and control principles – Current control variable reluctance motor service drive. Brushless DC Motor Drives: Three phase full wave Brushless dc motor – Sinusoidal type of Brushless dc motor- current controlled Brushless dc motor Servo drive.

REFERENCES:

• 1. Fundamentals of Electrical Drives – G. K. Dubey – Narora publications – 1995.
• 2. Electric Motor Drives Pearson Modeling, Analysis and control – R. Krishnan – Publications – 1st edition – 2002. st
• 3. Modern Power Electronics and AC Drives B K Bose – Pearson Publications 1 edition
• 4. Power Electronics and Control of AC Motors – MD Murthy and FG Turn Bull Pergman Press st 1 edition
• 5. Power Electronics and AC Drives – BK Bose – Prentice Hall Eagle wood diffs New Jersey - st 1 edition
• 6. Power Electronic circuits Deices and Applications – M H Rashid – PHI – 1995. M. Tech – I Year – II Sem. (PE/PEED/PID)