Simulation Running too slow

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Rajendra
Rajendra on 18 Aug 2011
I am trying to do a simple power system simulation. I just need to view the rms value of current. But since, the simulation is running very slow at steps of 1e-8 seconds, I am only getting instantaneous value. How to just solve the circuit for steady state condition? Here is a picture https://lh4.googleusercontent.com/-tBjv-eZlM2I/Tk1auvIklLI/AAAAAAAAA80/YeXeE8z1q0A/s800/too_slow.JPG
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Fangjun Jiang
Fangjun Jiang on 18 Aug 2011
Any particular reason using such a small step size? What is the frequency of the signal that you are simulating?
Rajendra
Rajendra on 19 Aug 2011
I am not using any step. It automatically does that. I simply hit run. Its 60 hz ofcourse.

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Answers (1)

Fangjun Jiang
Fangjun Jiang on 19 Aug 2011
I don't have that Toolbox. I remember reading some posts here that the simulation step is variable step. I think you can go to menu Simulation->Configuration Parameters ...Solver to set up the maximum step size. Step size of 1e-8 seems to small. 1e-3 sounds more reasonable.
  2 Comments
Rajendra
Rajendra on 19 Aug 2011
I just tried setting the min step size (which was previously set to auto) to 0.001.
But when simulating, I get this error message
Derivative input 1 of 'transmission/RMS/integ' at time 0.002200000000000017 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).
Fangjun Jiang
Fangjun Jiang on 19 Aug 2011
Okay. There might be some dynamics that require small step size. To find out, you can choose fixed step size and then try-and-error a few times, form 1e-4 to 1e-5, 1e-6, etc.

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