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"Unable to meet integration tolerances" problem.

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Hi everyone!

Tonight I left running the simulation and this morning I found this error:

"Unable to meet integration tolerances without reducing step size below smallest value allowed (7.1072e-14)".

I have a 3-ph inverter system.
20 seconds from the start of the simulation there is a double open-phase fault simulated by a very very small load conductance (g=1e-8..maybe too small?) with a step block.

The strange thing is that it doesn't happen when I manually try the fault at 1 second from the start of the simulation.

Is it a problem about Plecs memory usage?
Maybe should I try to increase the conductance value because it is too small?

Also another question:
I have read that when there is the "Cyclic behavior" one of the possible solutions is to increase the diode turn-on threshold. Is this threshold a "voltage threshold" like Vt=0.7 or a "time delay"?

Thank you in advance!

Bye
asked Jul 27, 2018 by nikilito (93 points)

1 Answer

+1 vote
 
Best answer

Hello,

Unfortunately we do not have enough information on the error you are encountering to make a suggestion here. For very specific modeling issues we request that you attach an example .mdl or .plecs file, or contact our support team at support@plexim.com.

Also, this text is from our user manual regarding the diode turn-on threshold setting:

Note  The Diode Turn-On Threshold is not equivalent to the voltage drop across a device when it is conducting. The turn-on threshold only delays the instant when a device turns on. The voltage drop across a device is solely determined by the forward voltage and/or on-resistance specified in the device parameters.

I hope this helps.

Best,

Kris

answered Jul 31, 2018 by Kris Eberle (1,078 points)
selected Aug 13, 2018 by nikilito
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