Simscape AC Current Source issue

Hello Community,

I would like to simulate a street with Simscape, and i wanted to use a AC current source to supply from residents. As i learned it is the same issue with the simple AC Voltage Source, that even i use 3 phase breaker at both side, and wswitehced off, during the simulatin the status of the breaker is not relevant.

This is the subsystem is use:

There is the two 3 phase breaker (I iknow it is not necessary, but i dont have other idea), what is by default closed.

When i make a simulation with both breaker open status:

The value of the current is added even it is switched off. This should be the values, when the breakers are open ( i delete the 3 AC cource):

Every section i made an option to break the line, so i did it to see, and the result is, that even the breakers are in open position, it is still count:

Other, that i tried with closed breakers, and nothing change, therefore i think is is an issue with the calculation.

Do anybody have any idea what is goint on?

Thanks.

PS: The model works more less with the controlled AC source, but it is changing even i set the designated AC Current, SO therefore i would like to try another source.

Answer 1

[Sabin]

If I understand correctly, the issue is a current source in series with a switch (circuit breaker) that is not behaving as expected. The physics behind is simple, the current source will force the desired current into the circuit. By adding a switch will not help making that current disappear. The ideal current source will be maintaining the current no matter what. If we consider the switch to have 0 off conductance (infinite resistance) we will run into solver issues because of conflicting equations. Even if we assume that we have an ideal current source and an ideal switch we would probably cause a huge voltage that would arc.

Answer 2

[Mátyás]

Dear Sabin,

Yes, you understand correctly. I am not agree about your view "The ideal current source will be maintaining the current no matter what", if there is no physical connection.

Anyhow, for my thesis i do it another way, and it was worked, and i understand your point of view, so we close this discussion.

I thought if i disconnect the ideal current source from the network (i thought the circuit breaker will cut the line as in the real life), then the ideal AC source cannot maintain the current (and voltage as well).

Thanks for your time and investigation about this topic. If i will use this Simscape again, now i will know how it will work.