Simulation with average model in LTSpice, time step too small error

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diablo77521

Joined Jan 16, 2017
3
I am trying to simulate with average model, PWMCM, and have modified a new symbol for it. However, I am getting a 'time step too small' type of error. I've tried increasing the Trtol value (as SgtWookie suggested in an older thread) bringing it up to over 20, but still have the same flavor of error.

Any suggestions? I've attached the model, symbol (had to zip these to get them to attach) and circuit files.

Thank you for your help!

upload_2017-1-17_13-50-54.pngupload_2017-1-17_13-52-6.png
 

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crutschow

Joined Mar 14, 2008
34,284
A few things to try in the SPICE section of the Control Panel:
upload_2017-1-16_22-18-12.png

Try the Gear or Trapezoidal integration method.

Increase all the simulation tolerance limits on he right by a factor of 10, i.e. Gmin from 1e-012 to 1e-11, etc.
 

eetech00

Joined Jun 8, 2013
3,859
I am trying to simulate with average model, PWMCM, and have modified a new symbol for it. However, I am getting a 'time step too small' type of error. I've tried increasing the Trtol value (as SgtWookie suggested in an older thread) bringing it up to over 20, but still have the same flavor of error.

Any suggestions? I've attached the model, symbol (had to zip these to get them to attach) and circuit files.

Thank you for your help!

View attachment 118879View attachment 118881
You can use functions with resistors but not with capacitors.

R=funct()

Check the help file...
 

Alec_t

Joined Sep 17, 2013
14,280
Your average model hasn't uploaded.
I often find the timestep problem can be cirumvented by changing a component value slightly.
 
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