How to change phase in Phase shift full bridge?

Hello everyone. I'm now trying to simulate a PSFB. Basically, it's a isolated chopping DC-DC transformer. Instead of controlling the duty cycle, you control the phase for 2 of the PWM. You will then allow more or less power to flow.

The problem is: How to dynamically change the phase with a feedback loop

-Of a controled PWM voltage (the parameter is "TD", time delay.)

-Of a pulse generator (parameter "phase delay")

I have been trying to use a S function. I can succesfully change the duty cycle (actually, S function are quite easy to use, and very useful ^^). I can change a lot of parameter, but not the PHASE DELAY .

Here is the error message: " Error evaluating registered method 'InitializeConditions' of MATLAB S-Function 'variablePhase2' in 'phase_shift_bridge_v0_2/Level-2 MATLAB S-Function'. The following is the MATLAB call stack (file names and line numbers) that produced this error: ['D:\Velocar\Battery_Charger\Electrical_circuit\variablePhase2.m'] [53]

Cannot change parameter 'Phase delay (secs): (PhaseDelay)' of 'phase_shift_bridge_v0_2/Pulse Generator2' while simulation is running"

I am really stuck on this one. I have read many document about S function, and I don't know what's going on (except that it seems that some parameter of Simscape component cannot be modified by S function. But why the phase delay can't be touch during simulation while duty cycle can?)

As always, I will look for an answer, and if I find something, I will let you know =D

Answer 1

[Kevin]

I made my own s-function in order to do that. You can't modify certain parameter during simulation, so I made my own PWM generator

I attached my file for the s-function. If you want to re use it, you will have to read it and create a s function block with the right name.

Cheers =D

[sanu joy]

Hi kevin,

Could you please share the file "Electrical_circuit\variablePhase2.m".

it is not included in the zip file.

Answer 2

[Jos van Rens]

Hi Kevin

Will it be possible to get the s-function variablePhase2

It was not in the *.zip

Best regards

Jos van Rens

[sanu joy]

Hi jos,

do you have this s-function variablePhase2 file.

please share if you have this.

Regards,

Sanu Joy