How could I display only steady-state responses in a scope?

Question

Hi all,

Firstly, sorry for bad English.

I need some help. Well, I have made a simulation model of synchronous generator connected to the grid powered by constant torque and all responses have oscillations at the start of the simulation (example in attachment). My problem is that I should represent only steady-state response and not transient response, so my mentor told me to try option “stored system state” but, obviously, I’m using this option in a wrong way. So, after 8. second is steady-state response.

How could I display only steady-state responses in a scope?  How to use this option “stored system state” to achieve this task?

Thank you very much.

Answer 1

Hello,

Please see the Steady-State Analysis tool built into PLECS. You can search for this in the documentation for full resources on how to use the tool. In PLECS Standalone the tool can be accessed from the Simulation Menu > Analysis Tools and in PLECS Blockset you can find the block you need in the PLECS Extras library. I believe you will find this to be faster and easier than the process you are pursuing currently. By the way, to fully answer your question, the method for using saved states is basically:
1) to run a transient simulation for an amount of time that allows the system to reach steady state
2) then store the current state (which is the final/steady state of the system)
3) then run a new transient simulation from the stored system state.

Best regards,

Kris

Comments

I should clarify that the Steady-State Analysis is not guaranteed to work with an AC systems, but providing the machine with a constant torque may allow it to. The second option, where a two-step process is used to start simulations from a point where the system transients have already settled, should certainly work.