Electrical Machine Analysis & Control (3 credits)

Course Description

The first part of the course deals with developing dynamic models for electromechanical systems, especially three-phase induction motors. The scope of using the developed models to implement high performance control schemes for the machines will be discussed in the later part.

Prerequisites

• Electrical Machines (EE2200) or equivalent

• Basic understanding of differential equations and matrix theory

Topics that will be discussed

• Review of magnetostatics and introduction to simple electromechanical systems

  • Magnetostatics fundamentals – Coupled linear magnetic circuits – Modeling simple linear motion electromechanical systems – Cylindrical motion electromechanical systems – Multiply excited electromechanical systems – Nonlinear magnetic systems – Energy and Co-energy methods – Elementary ac motor – Simulation methods – General considerations on modeling and simulating electric machines in Simulink

• Modeling Three-phase induction machines

  • Distributed windings – Inductance of a distributed winding – Three phase distributed windings – Mutual inductances of three phase distributed windings – Three phase induction machine – Stator to rotor mutual inductances – Air gap mmf – Voltage and flux linkage equations in phase variables – MMF equivalence and change of variables – Amplitude invariant and Power Invariant Transformations – Machine model in stationary frame – Transforming to rotor reference frame – Machine model in arbitrary rotating reference frame – Equations in field oriented reference frames – Space vector notations – Model using space vectors – Generalised model for system of coils

• Introduction to control

  • Seperately excited DC motor dynamic model – Speed control techniques: Armature and Field control – 4-quadrant dc-dc converter – PWM modulation technique – Armature controlled DC motor drive – Torque regulation – Speed Regulation – Design of current control loops – Design of speed control loop - Integrator antiwindup – Flux weakening operation – Rotor field oriented control for induction motors – Model based speed estimation for sensorless control

Textbook

• P. C. Krause. Analysis of Electric Machinery and Drive Systems. Wiley, 2013.

• R. Krishnan, Electric Motor Drives: Modeling, Analysis, and Control. Prentice Hall, 2001.

Grading

• Assignments: 40%

• Midterm exam: 20%

• Final exam: 40%