How does a cascade control system enhance performance?

A cascade control system enhances performance primarily by using a secondary controller that adjusts based on disturbances. In a cascade control strategy, the primary controller handles the main process variable, such as temperature, while the secondary controller manages a more specific variable, like the flow rate or pressure. This division allows the secondary controller to respond to disturbances more effectively and quickly, minimizing their impact on the overall system.

For instance, if there’s a change in flow rate due to a load disturbance, the secondary controller can adjust immediately to maintain the desired temperature setpoint by compensating for the flow change. This makes the control system more responsive and increases its stability, leading to better overall performance in process control.

The other options do not directly address the significant performance enhancement provided by a cascade system. Redundancy in controls, while useful for reliability, does not inherently improve performance. Implementing a feedback loop is a basic control principle that exists in many control systems, not just cascaded ones. Simplifying the control structure may help in some scenarios, but it does not particularly highlight the key advantage of responsiveness to disturbances that cascade control offers.