Low pass filter in Simulink

I want to determine the parameter of a LPF considered to have the transfer function: K/(0.001s+1), which has to control a photovoltaic system. I`m trying to determine it with Signal Constraint block, but with no success. The input is a ramp signal of 0.0028 .

The main idea is to use a low pass filter to control the photovoltaic system (developed with SimMechanics), and the previous one is what i thought of.

Can someone point me to the right direction? Either of another LPF to use, or how to properly determine the K parameter.

Thank You!

Irina

Answer 1

[Ryan G]

If you have access to control design tools then you can tune the gain to stabilize the system. Depending on the design it may not even be possible for this to control the system.

If you have little knowledge of control I would try this. Seperate the filter to -> K -> 1/(0.001s+1) ->. Now replace the K (which should be a gain block at this point) with a PID Controller block which is in the Continuous Simulink library. Note: you need Simulink Control Design to do this.

Open the PID block. Once you've done that set controller type to P (this P is your gain, K). Now click the Tune button. If you're system can be stabilized this should in theory allow you to use a slider to tune your gain.

A couple notes on this approach:

1) This hinges on the fact that you have a model that can be properly linearized. This may not be the case. 2) You need the appropriate control toolboxes.

Good Luck!