Syllabus for ENGN1931F Introduction to Power

Course Description: An introduction to the generation, distribution and use of electrical energy in three-phase balanced systems. Topics include: properties of magnetic fields and materials; magnetic reluctance circuits; phasors and the properties of balanced three- phase voltage and current lines; generators; and transmission lines; induc- tion motors; brushless DC motors; power semiconductor ; and the properties of solar photovoltaic sources and microinverters. Laboratory project. Prerequisites: ENGN0510 and ENGN0520.

Class time and location: MWF 1:00 to 1:50 in B&H 165

Notification: I hope to have a field trip to see the Manchester Street by the Point Street bridge across from Fox Point. This is not assured yet but you need to be aware that it may be a part of the course. I am told that if you know this before you start the course, we may not need to file waivers of liability for the journey. (It’s walking dis- tance from campus!) I am also angling to get a Providence entrepreneur to come talk about a new approach to photovoltaic inverters.

Rationale or Why take this course?: This course discusses the conversion of mechani- cal energy into electrical energy and back again to mechanical with motors. It should be accessible to both electrical and mechanical and others with the background of ENGN510 (E & M) and ENGN520 (basic circuits). This material was the earliest basis for when it became a separate profession at the end of the 19th cen- tury, yet this is also a field that is changing rapidly.

New materials, especially powerful permanent magnets, and more capable power semi- conductors have led to compact powerful brushless motors for robots, hybrid cars, and energy efficient appliances. Your refrigerator is quieter and uses less energy; a Prius gets 45 miles to the gallon; and Chinese export restrictions on rare earths can trigger a trade war. The evolution shows no signs of ending soon. Silicon carbide MOSFETs for high power and gallium phosphide ones for low power are coming along to replace some silicon devices.

These new motors require microprocessor-based controls and programmable operation. Power semiconductor switches make this possible. The same techniques make induction motors, the most common older motor type, into variable speed devices, lowering costs and saving energy. Your washing machine doesn't need a gearbox anymore.

At the same time, the utility industry has seen the Perfect Storm. Changing availability of fossil fuels is changing the structure of generating facilities. Concern about the climate effects of carbon dioxide emissions complicates planning new generators. There is great pressure to incorporate resources into the existing grid while utility en- gineers and administrators worry about the effect of those sources on the adequacy, relia- bility, stability and cost of the system. Aging infrastructure needs rebuilding and exten- sion through the development of a “,” that is, computer and communication technologies must be applied to modernize the distribution system within limited availa- bility of capital. Political problems have made the acquisition of new rights of way very time consuming while energy conservation has worked well enough to make future re- quirements more difficult to forecast. Finally, a disproportionate fraction of utility engi- neers is near retirement, opening job opportunities for which there is no obvious pool of replacements.

Our food supply gets studied extensively because everyone eats and has an idea of what hunger is. Is the supply adequate, nutritious, excessive, sustainable, local, carnivorous, vegetarian, global, etc.? But is almost as important to our way of life. It is even hard to see how food would be efficiently distributed without . As such, electrical energy should get similar scrutiny to how we think about food. Unfortunately the almost abstract nature of electric fields and electrical energy make understanding the system difficult. This course is not about green energy but about the immutable laws that govern electrical systems and the beautiful systems that engineers have built based on those laws. You can only think productively about things you understand, so take the course.

ABET Goals: By the end of the course you should be able

1. To explain how the electrical distribution system works from first principles to motor and lighting circuits; (ABET goals - a, g) 2. To design and build small motor controllers; (b, c) 3. To formulate a problem in power flow in a large system and simulate it; (a, e, k) 4. To research and present a problem in an energy or electromechanical system; (e, g, j)

Outline of Topics: (Extremely approximate plan. I adjust in part based on your inter- ests.)

 The magnetic field: Ampere's and Faraday's laws, flux conservation and magnet- ic circuits, and flow (4 classes)  Three-phase balanced systems of voltage and current: instantaneous power, real and reactive power, wye-delta transformations (2 classes)  Transformers: ideal and full matrix models, basic design, leakage inductance, regulation, three-phase windings, applications (3 classes)  Transmission lines: models, voltage levels, topologies, failure modes (3 classes)  Synchronous generators: coil structure, excitation, modeling real and reactive power flow (3 classes)  Induction motors: physical basis, three-phase and single phase designs, circuit models, size to power scaling (5 classes)  Semiconductor and switches: IGBTs, MOSFETs and thyristors, princi- ples of drives (4 classes)  The brushless DC motor: rotating B-fields, torque scaling, start-up and position sensing (3 classes)  Utility system power flow: simulation, real and reactive power balance, energy markets, system operators (2 classes)  Photovoltaic energy as a supplement to conventional sources – typical circuit de- sign of small to medium scale inverters (3 classes)  Presentations on paper topics (2 classes)

Assessment: The approximate weights of the various components of the course are:

 Four or five short homework assignments - 25 %  Lab project – programming a 3-phase motor controller 15 %  Two short labs measuring and analyzing a and a single-phase induc- tion motor - 15 %  Class presentation of a paper topic - 15 %  There will be a final paper of 5 - 10 pages on a topic of your choice related to the course. It will be due after you give a presentation on that topic so you can make changes to the paper based on class response - 25 %

Final Paper:

I would like to have you choose a paper topic and let me know what it is by Spring Break. Then around April 15th I would like to know what resources you have found to base the paper on. The course material is primarily a survey of practice in the utility and businesses. For a paper you can range more widely, for example, to look as sources of power, renewable energy issues, magnetic levitation for trains, etc. Be imaginative. For possible topics you might consider EROEI – energy return on energy invested, do such things as solar cells make an attractive investment in the sense of giving more energy back for a given amount of energy used in manufacturing, building, and maintaining the system. Or perhaps, what are the effects on the overall cost and stability of electrical supply of large amounts of renewable energy? Both topics have been the subject of considerable debate.

References and Resources:

Hughes, A., Electric Motors and Drives, 3rd Ed., Newnes, 2006.

Schavemaker, P., van der Sluis, L., Electrical Power System Essentials, John Wiley, 2008.

Sarma, M., Electric Machines: Steady-State Theory and Performance, 2nd. Ed., Cengage Learning, 1996.

Grainger Jr., J., Stephenson, W., Power System Analysis (paperback), McGraw Hill, 1994.

Teodorescu, R., Liserre, M., Rodriguez, P., Grid Converters for Photovoltaic and Systems, Wiley, 2011. Volke, A., Hornkamp, M., IGBT Modules: Technologies, Driver and Application, In- fineon Technologies, AG, Munich, 2012

Vanek, F. M., Albright, L., Energy : Evaluation and Implementa- tion, 2nd Ed., McGraw Hill, 2012.

Shoucair, F. S., Energy Conversion: Class Notes for EN167, Brown University, 1993. www.powerworld.com, power distribution simulation software - education edition.