# EECS 419: Electric Machinery and Drives

**Instructor**: Professor Heath Hofmann

**Coverage**

In this course we will cover fundamental electromechanical, power electronic, and control theory in the context of electric drive systems. The capabilities and limitations of different types of electric machines (e.g., permanent magnet, induction) in various drive applications will be covered. MATLAB® Simulink® models will be used throughout the course to give students exposure to the dynamic behavior of these systems. Finally, a three-hour lab will be held each week to give the students hands-on experience with electric machines and drives.

**Lab**

The labs will consist of giving the students hands-on experience with electric machines (AC and DC), power electronic circuitry, and control algorithms for electric drives.

**Textbook(s)**

No textbook required.

**Syllabus****1. Prerequisites**: EECS 215 and 216, or graduate standing

**2. Lecture, Lab Times**:

Lecture: Tu, Th 9-10:30am

Lab: Lab times to be determined.

**3. Purpose**: In the struggle to address today’s energy and environmental challenges, many potential solutions require electro-mechanical energy conversion. Examples include electric propulsion drives for electric and hybrid electric vehicles, generators for wind turbines, and high-speed motor/alternators for flywheel energy storage systems. Each of these systems contains: an electric machine operating either as a motor, a generator, or both; a power electronic circuit which interfaces the machine to a power supply or an electrical system; and a controller which measures electrical and mechanical quantities and uses this information to control the power electronic circuitry. In this course we will cover fundamental electromechanical, power electronic, and control theory in the context of electric drive systems. The capabilities and limitations of different types of electric machines (e.g., permanent magnet, induction) in various drive applications will be covered. MATLAB® Simulink® models will be used throughout the course to give students exposure to the dynamic behavior of these systems. A lab will be held with the class where the students will obtain hands-on experience with electric machines and drives.

**4. Objectives**: Upon successful completion of this course, the student should be able to:

Derive expressions for forces and torques in electromechanical devices.

Understand how power electronic converters and inverters operate.

Possess an understanding of feedback control theory.

Analyze and compare the performance of DC and AC machines.

Understand the maximum power limitations as a function of rotor speed of the above machines when they are connected to electric drives.

Design control algorithms for electric drives which achieve the regulation of torque, speed, or position in the above machines.

Develop Simulink® models which dynamically simulate electric machine and drive systems and their controllers.

**5. Topics**

- Overview of electric machines and drives
- Review of basic circuits and systems theory
- Fundmentals of electromechanical devices
- Flux linkage/current relationships
- Energy, co-energy
- Calculation of forces and torques

- Fundamentals of power electronics
- Feedback
- Feedforward

- DC machines
- AC machines
- Equivalent 2-phase models of three-phase machines
- Surface-mount permanent magnet machines
- Sunchronous reluctance machines
- interior permanent magnet machines
- Induction machines

**6. Required Text**: None (course handouts)

Suggested Texts:

T. Lipo and D. Novotny. Vector Control and Dynamics of AC Drives. Oxford, 1996.

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

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

**7. Instructor**:

Prof. Heath Hofmann Office hours:

4116 EECS TBD

(734) 647-1107

hofmann@eecs.umich.edu

**8. Exams**: The class will have one in-class midterm (whose time has yet to be determined) and a final If you have a valid reason for missing the midterm, you must notify your instructor at least two weeks in advance so that a conflict exam can be prepared. Students from all sections will take identical exams. Exams are closed-book, but each student is allowed a single 8.5″ by 11″ note sheet. Exams are returned during recitation/laboratory sessions. Any student caught cheating on an exam will receive a grade of 0 for the exam. Additional sanctions may also be pursued, following university guidelines.

**9. Homeworks**: Homeworks will be assigned on a weekly basis. Each homework will have approximately six problems. In addition to the standard analytical problems, most homework assignments will also require the student to develop and model a system using Simulink®. Students are encouraged to discuss homework problems in groups. **However, each student must submit their own work.** Students submitting identical work will receive a grade of zero for the homework set. Unless otherwise noted, homework sets are posted on the CTOOLs web site and are due one week later in class. Problem set solutions will be posted on the CTOOLs web site. Graded homework sets will be returned in class. **Late homework will not be accepted. **However, the lowest homework score will be dropped in calculating your overall homework grade. In order to perform well on the exams, it is important that you work each problem assigned. Although your final homework grade may be unaffected if you do not turn in one of the problem sets, your exam grades, which play a much larger role in determining your final grade, will be adversely affected.

**10. Labs**: In addition to the lectures, a lab will be held every other week where the students will obtain hands-on experience with electric machines and drives. Students will submit a lab report for each lab. In addition to including the data obtained during the lab, lab reports must be well-written and clearly explain the concepts presented during the lab. Measured results will be compared to expected values, with any discrepancies clearly discussed.

Lab times will be established during the first week of classes, after student’s schedules have been submitted, to determine times that will work best.

**11. Grading:**

The following weighting factors determine your total course score:

Homework 25%

Lab Reports 25%

Midterm 25%

Final 25%

The class average does not determine the cutoff points for letter grades. Instead, the cutoff points reflect the technical competencies required of an electrical engineer. The following scale determines your final course grade:

A+ 95%-100%

A 90%-95%

A- 85%-90%

B+ 80%-85%

B 75%-80%

B- 70%-75%

C+ 65%-70%

C 60%-65%

C- 55%-60%

D+ 50%-55%

D 45%-50%

D- 40%-45%

E <40%

At the discretion of the instructor, the minimum score needed to earn a certain letter grade may be lowered, but it will not be raised.

**12. Web Page**: Problems sets and other important files and announcements will be posted on the EECS 498 CTOOLS site.

**13. Attendance**: Although attendance will not be taken, you are expected to attend lecture. It is a student’s responsibility to acquire handouts and information disseminated in class.

**14. Honor Code**: Students in the College of Engineering at the University of Michigan are expected to be intimately familiar with its Honor Code. Honor code details are found here.