Configurating of Cascade Control
Objective of the Application
A cascade control structure can be established if, beside the main process variable, more system variables are measured and fed back as auxiliary process variables, creating subordinate control loops. Thus there is a master (or main) control loop and a slave (or auxiliary) control loop.
Cascade control is one of the most common control system structures in process plants.
The objective of this application note is to show the issues in configuration of cascade control loops that are particularly relevant to achieve fast dynamics and correct behaviour in all operating modes of real world applications.
The following issues are discussed in this application note:
- Interaction between master and slave controller with respect to controller tuning
- Interaction between master and slave controller with respect to operating mode changeovers
- Simulation example
This entry was created with SIMATIC PCS 7 V7.1, the procedure is transferable to PCS 7 V7.0 SP1 and higher versions.
05/2010 First release