Instructor: Professor Marc Bodson

Office: MEB 3254, Tel.: 581-8590

E-mail: bodson@ee.utah.edu

Class: TH 4:00PM-5:00PM, EMCB 105

Electric actuators are at the core of many industrial applications, including manufacturing, process control, and transportation. New developments in power electronics and computing technology have made it possible to control a variety of motors, including AC motors, and to achieve fast and precise tracking. Advanced features of computer-controlled systems, such as adaptation and efficiency optimization are also becoming increasingly common.

The objectives of the course are to:

• provide an understanding of the operation of the motors, of their state-space models, and of the use of these models for simulations and for control system design.

• give a working knowledge of methods used for the control of DC and AC motors, including open-loop and closed-loop methods and the selection of the controller parameters.

Introduction to electric motors: Basics of electromagnetic energy conversion and derivation of electric motor models. Linear and switching amplifiers, pulse-width modulation. Power electronic devices, topologies of electrical drives, and quadrants of operation. Optical encoders, resolvers, and other position sensors.

Control of brush DC motors: Construction and operation of brush DC motors. Model of a permanent-magnet brush DC motor. Steady-state characteristics and torque limits. Dynamic response under voltage and current command. PID control laws for speed and position regulation. Switching and time-optimal control algorithms. Separately excited, shunt, and series DC motors. Field weakening.

Control of synchronous motors: Construction and operation of synchronous motors. Model of a two-phase permanent-magnet synchronous motor. Static and dynamic characteristics. Open-loop control, stepping and microstepping. Closed-loop quadrature control. DQ transformation and DQ model. Closed-loop control in the DQ frame of reference. Torque optimization and field weakening. Hybrid stepper motors and reluctance motors.

Control of induction motors: Construction and operation of induction motors. Model of a two-phase induction motor. Steady-state characteristics, equivalent circuit, and torque curves under voltage and current command. Open-loop control with constant V/f. Closed-loop slip control. Models in rotating frames of reference. DQ transformation for induction motors and field-oriented control.

Three-phase motors: Three-phase supplies and connections. Three-phase to two-phase transformation. Three-phase DQ transformation and unitary transformations. Model of a three-phase synchronous motor and equivalent two-phase motor model. Control of three-phase synchronous motors using the DQ transformation. Quadrature control and six-step commutation.

A basic course on control system design (El En 3510 or equivalent) is required. A course on state-space analysis (El En 6560, Me En 5210/6210 or equivalent) is recommended but not required.

There is no textbook for the course. Course notes will be made available at the University Copy Center (106 OSH).

Grades will be based on homeworks, labs, and a final project. There will be no exams. Homeworks will consist in exercises and in computer simulations. The simulations will implement nonlinear models of electric motors to analyze their responses and to design control systems. Laboratory experiments will complement the homeworks by providing practical experience with the control of DC motors, stepper motors, and induction motors.

Completion of a project is required for the class. A project may consist in an independent investigation of a topic related to the course, or in a survey of papers from the literature. Students are responsible for the selection of the topic of their project, and may consider subjects that are related to their own research. The timetable is the following:

The criteria for the grading of the reports will be:

(a) originality and critical thinking

(b) technical accuracy

(c) scope of the work

(d) quality of presentation (logical organization, clarity and neatness of the report).

In the case of a survey project, at least 5 papers from the research literature, organized around a common topic, will be reviewed. Findings will be summarized in the report, with copies of the papers attached in appendix. Examples of journals with contributions in the field of electric motor control are the IEEE Trans. on Industry Applications, the IEEE Trans. on Industrial Electronics, and the IEEE Trans. on Control Systems Technology.

Copying from the papers (or simply paraphrasing) will not be considered a valid contribution. Students are expected to write the report in their own words and to demonstrate that they have read the papers, understood them, and thought about them in a critical and investigative manner. Examples of contributions include: critical evaluation of the significance of the results, comparison of different approaches, independent verification of the results (e.g., through simulations), simplified or expanded analysis of the results.

Examples of topics include:

• Speed control of induction motors without position or speed sensors
• Failure detection and identification
• Self-tuning methods
• Control of reluctance motors in magnetic saturation
• Passivity and backstepping methods of control
• Sliding mode control
• New power electronics systems
• Rotor time constant estimation for induction motors.

The University of Utah seeks to provide equal access to its programs, services and activities for people with disabilities. If you will need accommodations in this class, reasonable prior notice needs to be given to the instructor and to the Center for Disabilities Services, 162 Olpin Union Building, 581-5020 (V/TDD) to make arrangements for accommodations. All written information in this course can be made available in alternative format with prior notification.