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ECE476

ECE476 (Power System Analysis) is a 3-credit-hour senior/graduate level course that satisfies the Technical Electives requirement for ECE majors. This course is only offered in the Fall.

Content Covered

  • Review of 3 phase systems from ECE330
  • Transmission line parameters, modeling, and analysis
  • Transformer modeling
  • Load and generator modeling
  • Per unit representation of electrical systems
  • Network modeling
  • Control of power systems
  • Setting up and solving the power flow problem
  • Economic dispatch
  • Unbalanced system operation
  • Transient stability

ECE476 starts with modeling basic components (transmission lines, generators, loads, and transformers) and builds up to modeling entire large scale electrical systems. ECE476 begins with basic three phase system analysis review (single phase equivalent, wye-delta conversion, complex power conservation etc.) from ECE330, but from a slightly different perspective. New content is then introduced when learning about transmission line modeling. While this content is somewhat familiar from ECE329, the approach is based on circuit analysis techniques rather than the rigorous physics of transmission line theory (no Smith charts!). The class then delves into transformer modeling and the different three phase transformer connections. ECE476 then continues by going into load and generator modeling and touches on the differential equations that govern generator operation and control. Per unit representation is introduced during this unit to help simplify basic generator-load systems. Putting all of this together, students learn how to use admittance matrices to fully model a system with multiple loads, generators, transformers, and transmission lines.

This modeling all builds up to the formulation of the power flow problem. When designing and analyzing large electrical system operation, it is vital to understand the voltages, currents, real power, and reactive power values at every bus. The problem is that we may only know a few of these quantities like a singular generator voltage or the impedance of a transmission line, so it is no easy task to figure out all unknowns. To solve for all of the unknown quantities within a power system, we have to employ nonlinear system solving methods that are iterative in nature and are similar to the Newton-Raphson method. The class delves very deep into the formulation of these methods, all of the assumptions needed, and the costs and benefits of each technique. Students get to write their own programs to solve basic power flow problems using methods such as Newton's method, DC power flow, decoupled power flow, and fast decoupled power flow.

Next students are introduced to the idea of economic dispatch (tertiary control) and learn about cost function modeling of generators. Control and mathematical optimization concepts are introduced as students learn about the economics behind power generation within our modern day grid.

Unbalanced system operation is introduced to students through the method of symmetrical components. Students learn about the different types of faults that can occur within a three phase system (single line-ground, line-line, double line-ground, open, balanced three-phase-ground) and how to model them using linear algebra techniques as well as basic circuit analysis.

Finally, students go back to generator modeling and dive deep into transient stability during fault conditions. The governing differential equations for generators are studied in depth and rigorously analyzed to build up to the equal area criterion for transient stability analysis. Parallels are drawn between generator transients and mass-spring systems to help students conceptualize the difficult topics.

Prerequisites

This class heavily relies on content from ECE330, particularly three-phase power, modeling of transformers and electric machines, and system stability. There are many topical prerequisites for this class as it relies on familiarity of differential equations, matrix algebra, and computer programming.

When to Take It

Take this course soon after ECE330.

Course Structure

This course has two midterms and a cumulative final. Homework is given weekly.

Instructors

The course director for ECE476 is Alejandro Dominguez-Garcia. He is a professional in the field of power systems and has been teaching this class for many years. The content has changed over the years, but Professor Dominguez-Garcia has his own set of notes that he regularly updates. Professor Bose also teaches this course.

Course Tips

Read the notes before the lectures as Professor Dominguez-Garcia goes through content at a fast pace.

Life After

After taking this course, you will be well prepared for a future career in power systems, or for graduate study in the power field. If you like the generator modeling and transient generator response section of this course, take ECE431 - Electric Machinery. If you liked the power systems control and economic dispatch sections of this course, take ECE486 - Control Systems and ECE490 - Introduction to Optimization. ECE464 - Power Electronics and ECE333 - Green Electric Energy are also good courses to take if you are interested in power systems. The direct next course is ECE530 - Large Scale System Analysis which is also only offered in the Fall.

Infamous Topics

  • Unbalanced system modeling: Unbalanced system modeling is a complicated topic that requires much more time to understand than other topics within this course.

Resources

Review your ECE330 notes before taking this course.