Current keeps flowing no matter if breaker is open or closed

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I have AC current sources connected with each other in parallel and to AC voltage source also in parallel. In each branch current source is connected in serial with breaker. I don't control breakers yet I just either keep them closed or open all the time and measure the current in each branch to see the effect. But it seems that no matter what I set as initial state open or closed the current stays the same as if there is no breaker at all. I wonder if this has anything to do with the fact that they are connected to current source? How do I enable the switching to work?

Answers (9)

Arne
Arne on 25 Mar 2013
Edited: Arne on 25 Mar 2013
I have a similar problem, a open breaker with a constant zero at the controll-input. No matter if there is a 0 or a 1 at the input i can measure the full voltage at both sides of the circuit breaker.
I would excpect ~0V at the one side of the breaker if the breaker is open.
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MATLAB Version 7.13 (R2011b) Simulink Version 7.8 (R2011b) Fixed-Point Toolbox Version 3.4 (R2011b) MATLAB Coder Version 2.1 (R2011b) SimPowerSystems Version 5.5 (R2011b) Simscape Version 3.6 (R2011b) Simulink Coder Version 8.1 (R2011b)

Murali Krishna
Murali Krishna on 2 Feb 2020
The problem seems to be exist for DC circuit only.
For AC circuit, the breaker works perfectly fine, whereas it not for DC circuit.
Try using IGBT with gate signal control for DC circuits.

Mat Nub
Mat Nub on 16 Jan 2013
I wanted to add that the only time system notices the difference between open and closed breaker is when I remove snubbers. But then the simulation doesn't work as you cannot have an AC current source and breaker in series without a snubber.

Arne
Arne on 26 Mar 2013
Ok, my problem seems to be a capacity problem. If the end of the circuit breaker is open i can measure the full voltage. If there is a load at the end of the breaker, the voltage is nearly zero.

Mat Nub
Mat Nub on 26 Mar 2013
Hi Arne,
For me it worked by setting the solver to ode23tb robust. This issue is described in breaker help, but a bit vague. :-)

George
George on 1 Aug 2013
I have the same problem and adding high resistance in parallel changes significantly the voltages of the whole circuit.Trying another solver didn't work for me as well. Any other suggestions?

Tony Castillo
Tony Castillo on 29 Jan 2016
Hello my friends i'm doing a simulation and my problem with the breaker seems be the same than you presented at the past, have you solved it?, anyone can writte me how to fix it?

Arjun Sujeeth
Arjun Sujeeth on 1 Nov 2021
Hey I would suggest this solution to you: try using 2 MOSFETS opposite to each other like shown in the Figure below. Thi should be a feasible solution

Michele Pinato
Michele Pinato on 1 Apr 2024
I had the same problem and for my purposes the solution was to use the ideal switch which seems to work well in DC circuits. You can find it under Library Browser -> Simscape -> Specialized Power Systems -> Power Electronics

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