6.334  Power Electronics

Design Project: Feedback control

Hi all,

A number of students were confused about the design and implementation of a feedback controller for the design project. Please note the following:

- The feedback loop must ensure that the converter output voltage follows a command reference voltage (14 V nominally in this case). This means that the controller will continuously adjust the duty ratio such that the 14 V is maintained at the output, in steady-state, under all operating conditions. If there is a load step or input voltage step that attempts to change the output voltage, the control loop compensates for that change (i.e., the error) and adjusts the duty ratio to bring it back to 14 V.

- Please refer to the control design example given in lecture for the boost converter (refer handout Control #3). This should guide you on how to approach your design. Root locus can be a useful tool in assessing the location of the closed loop poles as well as the response of the system. Refer to rlocus and step commands in Matlab.

- As mentioned in the design project handout, a PI controller is a common design option. Using just a proportional controller may lead to steady-state errors.

- In terms of controller implementation, the handout mentions that a mathematical model is sufficient (i.e., it is not required to realize your controller with a circuit). However, if you wish to do so, you may use behavioral voltage sources and / or opamps to implement common controller transfer functions in LTspice.

- If you have not already done so, please submit your report on Stellar.

Best regards,
Anas

Announced on 16 May 2019  3:13  p.m. by Anas Ibrahim Al Bastami

Extension on final project due date to Monday May 20th

Announced on 14 May 2019  7:15  a.m. by David J Perreault

Updated Lecture Notes for Today Available

An updated set of lecture notes for today, with additional pages covering SVM operation, limits and extensions upon basic SVM, is now available on Stellar under Materials - General.

Announced on 10 May 2019  3:23  p.m. by Haoquan Zhang

Quiz 2 Review Session Slides Online, Make up Quiz

Slides from today's review session are available now on Stellar.

Those who requested a conflict session should have received notifications already.

Good luck!

Announced on 07 May 2019  10:13  p.m. by Haoquan Zhang

Additional Practice Quiz Covering Harmonic Cancellations and Solutions Available

An additional practice exam (with solution) covering harmonic cancellation topics is prepared by Prof. Perreault and available now on Stellar.

Announced on 07 May 2019  2:06  p.m. by Haoquan Zhang