PWM and Subusystem problems

Hello, I'm working on some MPPT algorithms but first I wanted a good modular boost converter with controllable dudty cycle (most examples had fixed duty). Anyways I have the PWM working mostly. It works fine, but during simulation it show's the pulses on the scope but then they disappear after simulation is over except for this little bit at the end of the simulation. This happens when I put it in another model to control the mosfet as well. The PWM will show on the scope till the simulation is over then its the last few ms is the only thing it shows and the mosfet doesn't seem to operate properly. I'm very novice at Simulink so I'm sure its something silly. I'm using SimPowerSystems to do the boost converter FYI.

Here's the two different models

http://db.tt/Jn9rS6dq - pwm

http://db.tt/1kWCQLNx - Boost model

Any suggestions would be greatly appreciated

~Dustin

--UPDATE-- So I decided to take a fixed PWM controller and place it in the same simulation as my homemade one. It works exactly the same however it also gets chopped off after the simulation is done. I'm not sure what config is bad that's causing this. Everything is mostly default aside from the sampling frequency. 1e-6

Answer 1

[Fangjun Jiang]

By default, the Scope has a limit of 5000 data points. Double click the Scope block, click the second icon on the top for "Parameters", click the "Data History" tab, you will see it. You can un-check the option, or increase the number, or save the data to a workspace variable.

[Dustin]

Thanks! Everything's working great now. That's kind of a silly default.