Identification and autotuning of parallel cascade control system

摘要

In process industries, cascade system is desirable to reduce the effects of possible disturbances and to improve the dynamic performance of the distillation column. In the traditional series cascade control, both the manipulated variable and disturbance variables affect the primary output through the intermediate (secondary) output. In this work Calculation of interactive measures (RGA, NI & SVD) for different multivariable distillation columns are evaluated for finalizing appropriate input-output pairs, Different control schemes (centralized and decentralized) with PI/PID controllers for the multivariable systems are synthesized and implemented. Decoupling controls / Interaction reducers are developed when interaction effects produce a significant deterioration in control system performance, transfer function based system identification for parallel cascade control, Autotuning of parallel cascade control using relay feedback and set point relay.