Simulink: resistor with variable resistance during simulation

Hi. I´m trying to find a way to change the resistance in a resistor during simulation in simulink. I have been using the fundamental blocks in the SimPowerSystem package from Simscape and I have a functional circuit for non-variable resistors. What I want is a resistor block were instead of the parameter R (ohm) I could insert a vector with different resistance values. Is there such a block or is there a way to create a block of this kind? I´m currently using the "parallel RLC branch" block for my electrical components.

I will be using this to model a thermal equivalent circuit for a loudspeaker and this variable shifting resistance is supposed to model the forced convection created by the membrane during operation.

[Yuebin Zhou]

It is not possible to change the value of the R/C/L parameters during the simulation. SimPowerSystems calculates the state-space equations for a given set of R, L, and C parameters just before the simulation starts. The ability to force changes in the R/L/C parameters will require re-computing state-space equations on the fly. Hence, these parameters are set to non-tunable.

If you want a variable resistor, please see the component below:

http://www.mathworks.com/help/physmod/simscape/ref/variableresistor.html

[Pamela Jackson]

In this example, it says to connect physical signal at thr R input port. What is this physical signal to connect to it?

Answer 1

[Sebastian Castro]

The approach that Yuebin above proposed is good if you're using Simscape, SimElectronics, or the SimPowerSystems Simscape Components library.

If you're using SimPowerSystems Specialized Technology, these blocks won't directly connect. You would be better off creating a custom variable resistor as in the following example:

http://www.mathworks.com/help/physmod/sps/examples/variable-inductance-modeling.html

- Sebastian

[RAMI TROUDI]

I agree!