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create an overvoltage by switching of an inductive circuit

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Dear Forum,

I am trying to create an overvoltage by switching off an inductive circuit which is feed by a dc-voltage source.

The goal is to simulate a contactor that swithces off the inductance an this dreates an overvoltage which a varistor shall reduce.

Unfortunately I was not able to create this overvoltage by using a switch or breaker (controlled by a step). The failure message is mostly: The failure message is:
"The current through inductor Ueberspannung_01/L1 is forced to jump from 81967.7 to 0."

In LTSpice I was able to dreate an overvoltage with a controlled current source (ramping down the current from e.g. 10kA in 10ms to 0A), but this is also not allowed in Plecs.

Does somebody have an idea to model a realistic contactor switching of an inductive circuit creating an arc voltage and overvoltage ?

Thank You

 

asked Nov 27 by DirkO (12 points)
Only the MOSFET and IGBT with Limited di/dt components can be used to switch inductive currents, but I am not sure if these are appropriate for your application. You also need to properly parameterize them. You can however, look under the mask of these to see their implementation and possibly use them to create your own behavioral model.

1 Answer

0 votes
You cannot interrupt an inductive current in PLECS - using an ideal switch, that would result in an infinite overvoltage. You can, however, put a high resistor in parallel to your switch. This provides an alternative flow for the current once the switch is opened. The resistor value determines the overvoltage.

Note that a Breaker is not suited for this application. The Breaker only opens when the current through it is zero, which is never the case in your model.

Oliver
answered 5 days ago by Oliver Schwartz (299 points)
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