• Fulltext

       

        Click here to view fulltext PDF


      Permanent link:
      https://www.ias.ac.in/article/fulltext/sadh/045/0268

    • Keywords

       

      Cascade control; fractional-order PID controllers; model mismatch; robust; Smith predictor; stability analysis.

    • Abstract

       

      Industrial process control systems suffer from the overshoot problem. Designing the controller plant models by conventional Proportional Integral Derivative (PID) may increase the rise time, settling time and overshoot. Cascade control is a remedial measure undertaken to overcome these problems. In this paper, wepresent a new cascade model using fractional-order PIDs. The fractional-order cascade controller can be expressed by fractional-order differential equations. Different laws proposed in the field of fractional calculus form the theoretical part in evaluating the equations and designing the controllers. The new structure gives improved responses for the first-order and second-order systems with time delay. Better simulation results are obtained by introducing Smith predictor in primary and secondary loops. Detailed analyses have been done on the stability, performance criteria and disturbance rejection. The usefulness of this proposed cascade structure and its superiority over normal cascade are illustrated with examples.

    • Author Affiliations

       

      GARAI SOMNATH1 BASU PRIYOBROTO2 SUTRADHAR ASHOKE1 SENGUPTA ANINDITA1

      1. Department of Electrical Engineering, Indian Institute of Engineering Science and Technology, Shibpur, Kolkata, India
      2. Department of Instrumentation and Control Engineering, Calcutta Institute of Engineering and Management, Kolkata, India
    • Dates

       
  • Sadhana | News

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

© 2021-2022 Indian Academy of Sciences, Bengaluru.