Digital Control Question

so with digital control, can you dynamically change the coefficients that are used to compensate a Converter.

I read in the past, that one of the benefits of Digital Control was that you could change the coefficients in the last minute of production, but I was wondering if you could have an algorithm where one changes the coefficients during run time?

thanks
Mark

HW 7 - Simulation of G_vg and Zout

Hi,

I am able to plot G_vd but when I try plotting G_vg and Zout, the graphs do not get plotted? Spice does not indicate there are any errors in the circuit!

Anyone has suggestions?

HW #5 Solution?

I do not understand the HW #5 solution for the SEPIC nEET problem where we are told the solution has an error.

I do not understand the first line of the solution. I do see that the secondary voltage, referred to the primary is -vtest(D'/D) .


Also, for the s^3 pole term, I got a value R/(1+D/D')^2. I have attached that, I do not see any error in that, which does not agree with the HW solution.



thanks
Mark

HW6 Problem 1

This is a sanity heck. Should I be running into a lot of algebra when finding G? When I established reciprocity I ended up with a fraction with 16 terms in the numerator and 13 terms in the denominator. Should these results be more manageable?

DCM boost converter example

I think I am missing something in understanding how the equation for the power source value was derived in equation 11.57.Can someone elaborate on this?

CCM-DCM2 Model

Hello Folks

Did anyone find the model of CCM-DCM2 work? I can't get the output with this model.

Chapter 8, Factoring Polynomials

for pages 290-291 of book, using the inequalities of the coefficients, to factor a polynomial into an approximate form:

Must *ALL* inequalities be true to use, for example in equation 8.95.

If in equation 8.95, the first several inequalities are met, However one, such as |a4/a3| >> |a5/a4| is not met(an inequality that is later than the first two)..., could you still factor this into a form such as 8.94., and then do you go back and try and factor out the other terms into an approximate form?

I just wanted to make sure that maybe the book did not completely explain the issue.

thanks
Mark

Getting error when "getZDZN" function gets called (written by Riley)

Hi,
I am getting the following error when the "getZDZN" function (written by Riley Pack) gets called:
??? Undefined function or variable "Z".
Error in ==> getZDZN at 59 ZD = 1/Z;
Anyone else see that? Would appreciate any help.
Nitish

HW #5, nEET problem, identifying the wrong "R"

for the HW #5 problem where you identify the wrong value in the "solution" given, does it have the value
Z=R/(1+D/D')^2 ?

that is what I got, but I do not see any other terms, which makes me suspicious that it might be wrong.

thanks

"u" in DCM simuluation model

is u ("mew") for DCM in the simulation model for the averaged swith model always < 1 ?

HW 5, problem10.9 of book

Do we need to do Spice sims for this problem?

thanks
Mark

getZDZN function written by Riley

Hello,
In the getZDZN function written by Riley, I am trying to understand how the statement works and what it does. Can someone help?
if (strcmp(ssm(i,j).InputName, input) && strcmp(ssm(i,j).OutputName, output))
disp('Found G')
G = ssm(i,j);

Thanks,
Nitish Agrawal

setting "n" in the CCM3 model for flyback converter

Hello everyone,
This is regarding problems 10.4 and 10.10. I am trying to clarify if the CCM3 model should only be used when the transformer in the converter circuit is connected across the diode in the switch (as in the CCM3 equations it is the voltage across the diode switch, E(3,4) that gets divided by the transformer turns ratio). If the transformer in the converter circuit is not connected across the diode (as in the flyback converter), then shouldn't one be able to use the CCM1 model for the switch in that converter?
Thanks,
Nitish Agrawal

transformer.asy problem!!!

Is anyone having problems downloading the transformer symbol? I tried various browsers, but simply could not get a working symbol. In case anyone has a working transformer.asy file, kindly let me know. Thanks in advance.

HW4 P1: simulation

How are people simulating problem 10.4d in Spice? The averaged switch models say "no transformer," which I thought meant you can't use them with a converter with with a transformer like the flyback....

Matlab/Simulink Parameter alteration ?

in the first MATLAB/Simulink assignment, we had Rload as a top level parameter b/c the gain block was at the top of the schematic hierarchy. That made it easy to change the value of Rload.

How can you change a value of a parameter that is down lower in the hierarchy? For example, if you wanted to change Cf of the input filter?

thanks
M

HW3 problem 1a (Finding Zn)

So what it Zn found on item a? Is it infinite?

Code Question, salient.m

Quesiotion:

What does the 3 lines do near the end of the code of salient.m .... what is the purpose of doing this?


features.z = z;
features.p = p;
features.dc = dc;

HW 2, problem 1

I am confused by the instructions telling us to simulate with Rload equal to a value.

How do we set the Rload?

Rload = Vout/Iload.
Vout is set by the loop, but b/c we have losses I do not know exactly what Vout is for a given Duty cycle. If I did know it, I could specify the load current based on Vout & the expected Rload. I could derive (by hand) Vout as a function of all losses and elements, then set Iload, but I am assuming I should not do that.

Also, the problem says "Iout = 0", I assume this is meant to be referring to Iload?

HW2 Problem 1b (second question)

Are we supposed to find 2 RHP zeroes? I can only find 1 with my script (at around 0.224)

HW2 prob1

What does "standard normakised form" indicate?

tilde operator in Matlab?

hello,

can you explain to me what the tilde (~) operator does in Matlab?

ex #1: if ~isempty(z)

ex #2: if rem(n,2) ~= 0

thanks
M

HW2 Problem 1b

Hey all,

I understand I need to do a loop to find out the pair of RHP zeroes. The question I have is how to transfer the resistance value to the Simulink model. How did you guys do?

Thanks,

Fabio

HW2 Prob1

HW2 Prob 1 asks to use getSSM and salient files from 5807 library. I think I am not running the files correctly, I understand for getSSM file sys is the .mdl file, however for salient what is sys?

Is the output of one the input of other? I think I am missing something here...dont know what..