HOW TO MAKE ODE14X RUN WITHOUT ERRORS?

2 views (last 30 days)
Andreas
Andreas on 4 Mar 2013
Commented: doliph on 30 Jul 2014
Derivative input 24 of 'final3opamp/N-Channel MOSFET1' at time 3.0E-7 is Inf or NaN. Stopping simulation. There may be a singularity in the solution. If not, try reducing the step size (either by reducing the fixed step size or by tightening the error tolerances).
this is the error I get. I need a discret time solver in order to get the fft of some signals in my system. i use local solver(trapezoidal and backward) but it does nt produce quite good results- it is far too digital-many pulse-like oscillations ocure.
So I only need to run the fixed step ODE14X. any ideas?
thank you for helping.
  2 Comments
Andreas
Andreas on 4 Mar 2013
and when i changed the consistency tolerence to 1e-12 i get this kind of major error (which shows up in many occasions when i try to set the model up)
Steady state solve failed to converge. ...Nonlinear solver: failed to converge, residual norm too large. ......Here is the set of components with unconverged equations: 'final3opamp/N-Channel MOSFET' 'final3opamp/N-Channel MOSFET1'

Sign in to comment.

Answers (2)

Guy Rouleau
Guy Rouleau on 8 Mar 2013
Very likely this is because the dynamics in your model is too fast to be captured by the solver step size. You know... the Nyquist criteria.
This article should help moving from variable to fixed step:

ahmed
ahmed on 17 Apr 2013
Mr. Rouleau;
The PDF link was useful....thank you
But, still there is no direct solution to adapt the solver...! or even the system...!
My model is a Hybrid vehicle, including DC motor and Generic engine working together via PSD...the problem arises between the engine and the solver...any idea?
  1 Comment
doliph
doliph on 30 Jul 2014
Hi ahmed,
I am doing a doing a similar simulation to you but for a fully electric vehicle. I am running into the same issues. Were you able to resolve the problem?
Cheers,
Dustin

Sign in to comment.

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!