ECE 437/637

Power Electronics v1.1

Final Exam Due: Friday, Dec. 20, 2013

Final Exam rules:

This Final Exam is to be completed individually.

Consultation with other students from the class of any kind is strictly prohibited.

You may consult with the professor of this course, but no other faculty may be consulted.

Any deviations from the above rules will be treated strictly per university guidelines for

student conduct.

The exam is open book and open notes.

Report Content:

1) An abstract summarizing your work

2) A description of the problem and your approach in solving the problem

3) Presentation of your solution and results and/or any special problems or issues which

arose in your work

4) Some form of demonstration that the results are “reasonable” and/or “correct”

5) A summary and conclusions section

6) Listing of the program(s) used for simulation in an appendix

Exam Evaluation:

Grading of the exam will be based not only on the technical content of your report, but also on

the clarity in which you communicate your results. The degree to which your report meets all of

the requirements listed above will be part of the evaluation criteria as well.

Important Advice:

You are strongly encouraged to start your exam as early as possible. Do not wait until the last

few days to begin your work. The end of the semester is very busy for everyone. Do not expect

any time extensions.

Problem Statement:

Design the specific implementations of the power converters for the Uninterruptable Power

Supply (UPS) shown below. Develop a simulation with your selected designs.

3-phase

480V

LL-rms

Grid

3-phase

AC-DC

Rectifier

DC-DC

Converter

(battery

charger)

350V

Battery

Pack

DC-DC

Converter

(boost)

DC-AC

Inverter

Power

Output

Problem Statement (continued):

The UPS must be capable of:

- 3-phase, 480V-rms line-to-line voltage, 60 Hz fundamental

- 50A-rms phase current

- For EXTRA CREDIT (max of 10 points)

o Actively regulate the output current to a MAX of 60A-rms under a

symmetric RL load with R = 0.1 and L = 0.01 H per phase.

Simulate the following conditions to prove your design:

- Automatic switching upon loss of grid voltage

- For EXTRA CREDIT

o Short circuit protection response to a three-phase short on the output

Please confirm your compliance with the rules by completing the following:

I certify that the work in this exam is solely my own with absolutely no external input of any

type.

(signature) __________________________ Name (print) _____________________________

This page (signed) must be submitted with your report.