Anti wind-up Algorithm

[Bojleric]

Hi everyone...
I have a problem considering anti wind-up algorithm for PI regulator. I'm developing a regulation in Matlab Simulink. And I need a conditional integration anti wind-up algorithm. Help?

 

[stanmkatz]

The simplest anti windup algorithm is to limit the integrator. For a simple implementation I usually calaculate the Kp*E and Kd*(E - E(n-1)) terms first (this is a simple backwards difference differentiator) and then I make sure that the integrator (after adding the latest error) is less than (Max - P-term - D-term)/Ki and greater than (Min - P-term - D-term)/Ki.

It's usually simple since you only have to really check one of the limits each pass.