i dont understand the matlab fucntion any help ?please

[dpb]

Going to have to be more explicit than that, I'm afraid?

What, specific application of any is in question?

Answer 1

[Fangjun Jiang]

You need to double click that "MATLAB Function" block. It will open in an Editor. There will be MATLAB code in that function. Most likely, it won't be too fancy, just a single-input and single-output function. The input is Clock, which means the simulation time, the output is likely a curve depending on the time.

[Fangjun Jiang]

I won't be able to help you make these three Simulink models. But if you could show the code in MATLAB Function block, I could help you "understand the MATLAB Function" as you asked.

[dpb]

Your mission, should you choose to accept it, is to decide what the waveform voltage is for the lightning strike versus time and write a function to produce that. While I've never looked; I'm sure there's a whole literature field on characterizing lightning strikes -- I'm sure that also has a great range of variability.

One might consider looking at/for definitions of inputs specified for Underwriter Laboratories testing of such devices; my recollection is that they have defined standards for virtually all certification tests provided so vendors can know what their DUTs will be subjected to when submitted for approval.

[dpb]

Oh. OK, somebody (or you :) ) supplied a functional form from which to generate a pulse --

It looks like only two terms were/are used in the summation so you can just write them out directly as the two terms -- writing a subfunction for the expression would let you not have to duplicate all the code.

I don't know enough about the subject to know what MSS_SUB and MCS_SUB would be, nor about the initial stroke given the title of Table 5 being for "Subsequent" strokes -- but maybe that's the use of "subsequent" to mean two or more and the first is the initial, I don't know and there's insufficient context to know. You'd have to consult the reference to understand fully how to apply it.

So, give it a shot at translating the mathematical equations to MATLAB code -- "nothing venture, nothing gained!" and learning by doing is generally the best route to gaining proficiency over just being handed a solution.

Post your attempts and ask specific questions where get stuck...