RNGA based Centralized PI Controller for Multivariable Non Square Systems using Direct Synthesis Method
C.V. Nageswara Rao1, Putta Vihari2

1Dr. C.V. Nageswara Rao, Associate Professor, Department of Chemical Engineering, Gayatri Vidya Parishad College of Engineering, Madhurawada, Visakhapatnam (A.P), India.
2Mr. Vihari Putta, Operations Manager, Coal Gassification Plant, JSP-Angul, Odisha, India.
Manuscript received on 06 April 2023 | Revised Manuscript received on 17 April 2023 | Manuscript Accepted on 15 May 2023 | Manuscript published on 30 May 2023 | PP: 1-10 | Volume-12 Issue-6, May 2023 | Retrieval Number: 100.1/ijitee.F95180512623 | DOI: 10.35940/ijitee.F9518.0512623

Open Access | Editorial and Publishing Policies | Cite | Zenodo | Indexing and Abstracting
© The Authors. Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC-BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Abstract: Design of centralized PI controllers for multivariable non square systems is proposed in the present work. The centralized controller is designed based on the direct synthesis method. The method includes approximating the inverse of the process transfer matrix with the effective transfer function matrix. The effective transfer function for each element in the process transfer function matrix is derived by using the relative normalized gain array (RNGA), and relative average residence time array (RARTA) concepts proposed by Cai et al [1]. The transfer function models used in the present work include first order processes with time delay (FOPDT). Maclaurin series is applied to reduce the resulting controllers in to standard PI forms. The design method requires a single tuning parameter (filter time constant) to adjust the performance of the controller. Simulation study is carried out for various case studies and the results show the advantage of proposed method over the literature reported methods. The control algorithms are comparatively analyzed using standard robust stability measure. The designed controllers give a good performance with lesser interaction compared to the literature methods, Davison Method [2] and Tanttu and Lieslehto’s method [3]. 
Keywords: First Order Plus Dead Time, Multivariable, Centralized, Maclaurin Series, Pi Controllers, Relative Normalized Gain Array, Relative Average Residence Time Array and Effective Transfer Function.
Scope of the Article: Control and Automation