PID block in Simscape PowerSystem

Hello everyone,

I'm trying to implement a PID block in my power system, the image below show my system.

As you can see, I have this block called Controlled current source where I'want to control the amplitude of the sin wave current to a given active power.

To do this I'm using the ziegler-nichols method, so i can adjust the best parameters for this scenario. But while i'm trying to ajust the best P gain to obtain the Ku my system never get the stable and consistent oscillation.

Thus, I want to know if is needed to put some other block in the system like a memory block or something similar.

thanks in advance for your attention.

Answer 1

[Aravind Chidambaranathan]

Hi Diego,

I investigated about the issue you are facing with controlled current source block in SIMSCAPE. As I donot have your model for investigating, usually oscillations occur due to couple of reasons:

• In Controlled Current source block, setting default initial amplitude much far from steady state current may require more time to stabilise the system. If that is the case, try setting initial amplitude in the block to a ball-park guess rather than letting it at default 0 A.
• The simulation time may be much lower than final settling time of the system. If that is the case, try increasing the simulation time found near the 'RUN' button.

Do let me know if this works.