JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

Prerequisite

Power Electronic Converters, Electrical Machines

Course Objectives:

• To understand principle of operation of scalar control of AC motor and corresponding speed- torque 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 principle of operation of brushless DC motor.

Course Outcomes

After completion of the course, students will be able to:

• 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.

UNIT - I

RECTIFIER CONTROLLED DC MOTOR Separately excited DC motors and DC series motors with single phase semi converter and single-phase full converter, Three-phase controlled converter, control circuit, control modeling of three phase converter, Steady state analysis of three phase converter control DC motor drive, two quadrant, three phase converter-controlled DC motor drive, DC motor, load and converter.

CLOSED LOOP CONTROL OF DC DRIVE Current and speed controllers, Current and speed feedback, Design of controllers, Current and speed controllers, Motor equations, Filter in the speed feedback loop speed controller, Current reference generator, Current controller and flowchart for simulation, Harmonics and associated problems, Sixth harmonics torque.

UNIT - II

CHOPPER CONTROLLED DC MOTOR DRIVES Principle of operation of the chopper, Chopper with other power devices, Model of the chopper, Input to the chopper, Steady state analysis of chopper-controlled DC motor drives. Closed loop operation: Speed controlled drive system, Current control loop, Pulse width modulated current controller, Hysteresis current controller, Modeling of current controller, Design of current controller.

UNIT - III

CONTROL OF INDUCTION MOTOR Introduction to motor drive, Torque production, Equivalent circuit analysis, Speed – Torque characteristics with Variable voltage, Variable frequency, Constant v/f, Variable stator current operation, Induction motor characteristics in constant torque and field weakening regions.

STATOR SIDE CONTROL Scalar control, Voltage fed inverter control, Open loop v/f control, Speed control slip regulation, Speed control with torque and flux control, Current controlled voltage fed inverter drive.

ROTOR SIDE CONTROL OF INDUCTION MOTOR DRIVES Slip power recovery drives, Static Kramer Drive, Phasor diagram, Torque expression, Speed control of Kramer Drive, Static Scheribus Drive, and Modes of operation.

UNIT - IV

VECTOR CONTROL OF INDUCTION MOTOR DRIVES Principles of Vector control, Direct and Indirect methods of vector control, Adaptive control principles, Self-tuning regulator Model referencing control, Direct torque control of AC motors.

UNIT - V

CONTROL OF PERMENANT MAGNET SYNCHRONOUS MOTOR DRIVES Synchronous motor and its characteristic, Control strategies, Constant torque angle control, Unity power factor control, Constant mutual flux linkage control, Closed loop operation.

TEXTBOOKS:

• 1. R. Krishnan, “Electric Motor Drives Pearson Modeling, Analysis and control”, 1st Edition, 2002.
• 2. B K Bose, “Modern Power Electronics and AC Drives”, Pearson Publications, 1st Edition.

REFERENCES:

• 1. MD Murthy and FG Turn, “Power Electronics and Control of AC Motors”, Bull Pergman Press 1stEdition.
• 2. BK Bose, “Power Electronics and AC Drives”, Prentice Hall Eagle wood diffs New Jersey, 1st Edition.
• 3. M H Rashid, “Power Electronic circuits Deices and Applications”, PHI, 1995.
• 4. G. K. Dubey, “Fundamentals of Electrical Drives”, Narosa publications, 1995. M. Tech – II Semester L T P C 3 0 0 3