Given that cascade control loops are everywhere without much consideration as to dynamic requirements, what can we do to make the implementation effective? Here are some specifics by the way of detailed recommendations on the sequence, speed, and setup for tuning PID and digital valve controllers.
Did you know all loops today use cascade control? Do you understand how cascade control can correct for lower loop disturbances before they affect the upper loop and can make the upper loop faster? Do you know what to do to keep the system from oscillating if the lower loop...
Since most unit operations have multiple loops and streams, interactions can exist where the PID output of one loop affects the PID process variable of another loop and vice versa. Interactions can cause loops to confusingly burst into oscillations.