A Novel Indirect Approach for Modelling a Class of Fractional-Order System in Complex Domain

In this paper, a method is presented to obtain the discrete model of the fractional-order system (FOS) in complex \(z\) $z$ -domain. An indirect modelling approach has been implemented for the proposed work. Initially, a stable first-order discrete-time operator is formulated by interpolating Tustin and reduced Tick integrators. Later, the fractional-order differentiator has been modelled in two stages. The first stage employs Oustaloup method to obtain the approximate model of the fractional-order differentiator (FOD) in \(s\) $s$ -domain. The second stage uses the newly formulated operator to discretize the \(s\) $s$ -domain model for attaining stable discrete rational model of the FOD in \(z\) $z$ -domain. The efficacy of the proposed method over some of the prevailing methods has been presented with appropriate simulation outcomes.