73122 - Electric Drives (2nd cycle)

Course Unit Page

SDGs

This teaching activity contributes to the achievement of the Sustainable Development Goals of the UN 2030 Agenda.

Affordable and clean energy Industry, innovation and infrastructure

Academic Year 2021/2022

Learning outcomes

At the end of the course, students will be able to use electric technologies for the analysis, the choice and use of the main electrical drives for residential and industrial applications.

Course contents

DC motor drives

  • Separately excited DC machines. Mathematical model.
  • Steady state characteristics with armature and field control. Control of DC motors in the constant torque control region and in the field-weakening region.
  • Transition from driving to breaking operation.
  • Constant torque and constant horsepower operation.
  • Dynamic model of the DC machine.
  • Dynamic behavior of DC motors with constant flux.
  • Closed-loop control of torque and speed.
  • Field weakening.

Brushless DC motor drives

  • Magnetic circuit analysis.
  • Torque and back-emf equations.
  • Winding inductances and armature reaction.
  • Torque/speed characteristics: performance and efficiency.
  • Three-phase brushless DC motor.
  • Position sensors.
  • Drive characteristics and control principles.
  • Application of brushless DC motor drives.

Induction motor drives

  • Dynamic model of induction machines.
  • The dq machine and flux equations.
  • Torque equation. Principles of field orientation.
  • Machine equations and torque in the rotor flux oriented reference frame.
  • Decoupling control of flux and torque in the rotor flux oriented reference frame.
  • Flux models.
  • Direct scheme and indirect scheme of induction motor field oriented control.
  • Control of the induction machine supplied by current controlled PWM inverter.
  • Simulation of electromechanical transients.
  • Maximum torque capability of the machine in the flux weakening region. Applications.

Readings/Bibliography

Slides used during the lectures will be delivered by Insegnamenti On Line (iol.unibo.it).

  • I. Boldea, S. A. Nasar : ELECTRIC DRIVES, CRC Press, New York.
  • P. Vas: VECTOR CONTROL of AC MACHINES, Oxford University Press, New York.
  • T.J.E. Miller: SWITCHED RELUCTANCE MOTORS AND THEIR CONTROL.Clarendon Press, Oxford.
  • W. Leonard: CONTROL OF ELECTRICAL DRIVES. Springer-Verlag, Berlin.
  • I. Boldea, S. A. Nasar : ELECTRIC DRIVES, CRC Press, New York.
  • P. Vas: VECTOR CONTROL of AC MACHINES, Oxford University Press, New York.
  • T.J.E. Miller: SWITCHED RELUCTANCE MOTORS AND THEIR CONTROL.Clarendon Press, Oxford, 1993.
  • W. Leonard: CONTROL OF ELECTRICAL DRIVES. Springer-Verlag, Berlin, 2001

Teaching methods

The theoretical explanations are integrated by numerical simulations of electrical drives in SimScape/MATLAB

Assessment methods

The final test will be written with a number of questions, aiming at assessing:

- knowledge of electrical engineering technology;

- knowledge of electric machines and drives;

- capacity of design of electric drives;

The overall assessment will be based on the quality of the presentation and on the accuracy of answers.

Moreover, students shall prepare a report on simulations of electric drives with MATLAB/SimScape.

Teaching tools

Lessons are delivered with the aid of slides.

Numerical simulations of machines and drives are made in the classroom by MATLAB/SimScape.

Office hours

See the website of Alberto Bellini