Course Objectives:

1.      To impart knowledge about fundamentals of Electric drives and control.

2.      To understand the basic structure of electrical machines.

3.      To explain the operational strategies of dc and ac motor drives as per different quadrant operations.

4.      To discuss the modeling and control of dc motor drive, ac motor drives and permanent magnet machines.


Review of Drive Concept: Representation of electric drive, Different machines and load characteristics, Four quadrant operation, Equilibrium and steady state stability, Thermal and overload consideration of electric drives under continuous, Short and intermittent duty cycle.


DC Motor Drive and its Operational Strategies: Dynamic model of machine with armature voltage control only and converters with continuous conduction only; Closed loop control using single (speed) and two loops (speed, current), Implementation using circulating current type three phase dual converter and four quadrants transistorized chopper.


Modelling and Control of DC Drives: State feedback control and sliding mode control of separately-excited DC machine, Modelling and control of separately-excited DC machine in field weakening region and discontinuous converter conduction mode, Control of DC series machine.


Open-loop Dynamic Performance of AC & DC Drives: Starting & reversal time, Energy consumption.


AC Drives and its Operational Strategies: Variable frequency operation of three-phase symmetrical induction machine, Scalar control methods for constant power an constant torque modes, Vector control of induction machine, Methods of field sensing and estimation, Field orientation methods: Implementation of IRFO scheme using current controlled PWM, VSI and implementation of DSFO scheme using CSI, Performance of vector controlled permanent magnet machine.


Control  and Estimation of AC Drives: Introduction to speed control of Switched Reluctance Machine, Induction motor drive, Sensorless speed control, Direct torque control and flux observation, Speed control of wound rotor induction motors: Converter based static rotor resistance control, Static scherbius drive using line commutated converter cascade, Analysis and estimation of harmonics and power factor, Vector control of wound rotor induction machine using self-commutated converter cascade and improvement in power factor, Variable speed constant frequency (VSCF) generation. Constant Volts/Hz control, Scalar self-control of commutator-less motor, Vector control.


Control of Permanent Magnet Machine: Permanent magnet synchronous machine, Brushless dc machine, Surface permanent magnet machine and interior.


Laboratory Work:

Closed loop current-speed control of AC & DC drives, Variable voltage-variable frequency control, Vector control mechanism, Position control of stepper motor, Direct field orientation of AC drives, Static Scherbius & Kramer method of slip power recovery, PWM based VSI control of induction drive, Converter based Four quadrant operation of DC and AC drives.



Course Learning Outcomes (CLO):

On the completion of the course, the student will be able

1.      To acquire the knowledge of selection of drives as per practical operational industrial requirement.

2.      To apply their knowledge to prepare control schemes as per different types of motors used in industries.

3.      To estimate and solve harmonic and power factor related problems in controlling AC and DC drives.

Recommended Books:

1.        Mohan, N., Electric Drives: An Integrative Approach, MNPERE (2001).

2.        Mohan, N., Advanced Electric Drives: Analysis, Control, and Modeling Using Simulink, MNPERE (2001).

3.        Krishnan, R., Electric Motor & Drives: Modeling, Analysis & Control, PHI Pvt. Ltd. (2001).

4.        Miller, T.J.E., Brushless Permanent Magnet and Reluctance Motor Drives, Clarendon Press (1989).

5.        Krishnan, R., Electric Motor Drives: Modeling, Analysis and Control, PHI Inc. (2001).

6.        Dubey G.K., Power Semiconductor Controlled Drives, PHI, (1989)