Title: An enhancement in parallel cascade scheme for non-minimum phase system

Authors: Manish Yadav; Hirenkumar G. Patel

Addresses: Department of Electrical Engineering, S.V. National Institute of Technology, Surat, 395007, India ' Department of Electrical Engineering, S.V. National Institute of Technology, Surat, 395007, India

Abstract: This paper aims to control non-minimum phase (NMP) systems with dead time in the existence of uncertainty and disturbances. The parallel cascade control is utilised to motivate such problems, especially for slow process dynamics and actuator nonlinearities. The work's novelty is combining a higher-order fractional-filter with an inverse response and dead-time compensator in the internal model control (IMC) framework for designing the outer loop controller. The conventional IMC scheme is adopted for the design of inner loop controller. This modified structure is offered refinement in the gain margin for better robustness. The Riemann sheet principal investigates fractional quasi characteristic polynomial arising from the non-minimum phase systems with dead time. Further, a robustness test is also carried out via sensitivity analysis. The efficacy of the suggested method is illustrated via two case studies.

Keywords: non-minimum phase; NMP; parallel cascade control; IMC controller; robustness.

DOI: 10.1504/IJMIC.2023.129472

International Journal of Modelling, Identification and Control, 2023 Vol.42 No.2, pp.131 - 143

Received: 25 Sep 2021
Accepted: 06 Dec 2021
Published online: 10 Mar 2023 *

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