What is the purpose for the 'aw_type' PIDFF parameter.

The 'aw_type' is the anti-reset windup parameter used in the PIDFF function block.  This is a user defined input.

Anti-reset windup is a strategy used in integral controllers to prevent "integral windup," a phenomenon where the integral term accumulates excessively when the actuator is saturated. It prevents the integral from building up during saturation, which allows the controller to quickly return to normal operation, reduces overshoot, and improves settling time.  Common methods include clamping (freezing the integral), conditional integration (disabling integration when saturation occurs), and back-calculation (using the difference between desired and actual output to "unwind" the integral.

The PIDFF function block uses the bumpless back calculation method.

• A value of 0 is equal to no anti-reset windup.
• A value of 1 is equal anti-reset windup.

Udgivet til: Schneider Electric Danmark