Robust Fractional-order NPD Controller for NPK Power Model of an AHWR System

Nonlinear dynamics are critical in nuclear power reactors such as Advanced Heavy Water Reactor (AHWR). The core of AHWR must be governed and controlled by a suitable and reliable controller to deliver the demand electricity properly. In this paper, a fractional-order nonlinear controller (FO-NPD) comprises of fractional-order (FO), nonlinear (N), and proportional plus derivative (PD) terms are proposed and incorporated into the normalized point kinetics (NPKs) model of AHWR core for trajectory tracking performance, disturbance rejection, and noise suppression analysis. The FO- NPD controller gains are modified at run-time using the cuckoo search algorithm (CSA) based on a performance metric index termed as the sum of the integral of square error (ISE). The tuned gains get modified in real-time which makes the recommended controller more resilient and robust. To validate the obtained simulation results, a comparative performance study is carried out between the proportional plus derivative (PD), the fractional-order proportional plus derivative (FO- PD), and the nonlinear proportional plus derivative (NPD) with the proposed FO-NPD controller. And it is observed that the proposed controller demonstrates the superiority over other three controllers.