variation of the parameters of a diode during simulation

I want to vary the Reverse breakdown voltage of the diode, during simulation on simulink, the new parameter will be calculated using a small algorithm on state flow, this algorithm retrieves simulation values and calculates the new optimal voltage, then impose it on the diode, which means, state flow retrieves data during the simulation and calculates the new parameters and applies them to the subsystem, all without stopping the simulation

Answer 1

[Fangjun Jiang]

The value of a "parameter" of a block is designed to be constant during a simulation. There are ways to pause a simulation, change its value and then continue the simulation. It is not designed to work in your expected fashion, which is to change its value at every simulation step, which is the same as any other dynamic variable.

You may have to change your modeling. One example I always give is that, if you want to change the "gain" value of a Gain block at every simulation step, then you should use a "Product" block to "multiply" those two signals instead.

I am not aware of any block that can implement what you described.

[massinissa keciri]

in case, I would use a subsystem which would be executed after the calculation of V, am I running it for a period T, and at each execution, the initfct retrieves the new values of V,

[Fangjun Jiang]

I am not clear what you are trying to say

[massinissa keciri]

so i will do it step by stepassuming I create a subsystemthis subsystem does not work all the timefor it to run I must give a square signal, of period T, which corresponds to my desired simulation timeand I program the subsystem, in a way that it retrieves data in simulink, and it will use them as initial value before executingon the other hand the state flow works all the time, because it is not included in the subsystem

[Fangjun Jiang]

Please write the comments with proper punctuation.

[massinissa keciri]

so i will do it step by step.assuming I create a subsystem.

this subsystem does not work all the time,

for it to run, I have to give it a square signal, with a period T, which corresponds to my desired simulation time for this subsystem.

and I program the subsystem, so that it retrieves data from simulink, and it will use them as an initial value before executing,

on the other hand the state flow works all the time, because it is not included in the subsystem

[Fangjun Jiang]

The approach you proposed is unlikely to succeed. The inhibiting part is the "Reverse breakdown voltage" of the diode. It is a block parameter. The only way to change it during a simulation is to pause the simulation, set_param(block,'Reverse breakdown voltage',NewValue), and then continue the simulation. This is possible with a little bit programming.

Now, it sounds like you want to do this pause-set-continue multiple times according to a pre-defined timeline. This makes it even harder. This invoves reading the pre-defined timeline, make it pause at the right time, make it continue for the correct duration of time, etc.

The InitFcn callback of a block is executed only once at the begining of the whole simulation. It will not be executed multiple times when you enable or trigger a subsystem.

At a point of time, you have to admit that certain approach is a dead end, no matter how desirable it is. It is not your fault. It is the limitation of the tool.

If you know the modeling behavior of the diode in terms of external voltage and the "Reverse breakdown voltage", I would suggest you making a mathmatical model or physical model of the diode yourself.

[massinissa keciri]

in this case, is it possible, to access the diode subsystem, or its code, and make the reverse voltage an input, or a portin

in a way, to directly inject a signal that I get from state flow

[Fangjun Jiang]

I don't see any way other than you model it yourself. In R2022b, there is only one type of "Diode" block that has "Breakdown", "Reverse breakdown voltage" parameter. It doesn't have any option to make it a dynamic input.

[massinissa keciri]

thank you very much for your valuable information