Atom Search Optimized FOPI Controller of the DC–DC SEPIC Model with Matignon’s Theorem Stability Analysis

Abstract

In this work, the design and implementation of an optimized fractional-order proportional-integral (FOPI) controller for a DC–DC single-ended primary inductance converter (SEPIC) is considered to fulfill the application of power factor correction and voltage regulation along with improved robustness, efficiency, and performance characteristics of the converter. An Atom Search Optimization technique is proposed to optimize the parameters of the controller in the outer voltage and inner current control loop of the DC–DC SEPIC model. The model is developed using MATLAB –Simulink, and the simulation analysis is carried out at rated load, setpoint tracking, source voltage, and load variation. The effectiveness of the proposed atom search optimized FOPI controller is verified by comparing its performance with the particle swarm optimized FOPI controller. Furthermore, Matignon’s theorem-based closed-loop stability analysis is carried out for the tuned values of the FOPI controller with the SEPIC model. According to the simulation results, the proposed technique provides a more dominant dynamic response, an improved efficiency, and a power factor than the particle swarm-tuned controller of the SEPIC model. In addition, better voltage regulation is achieved in the case of source voltage and load variation. Furthermore, the closed-loop stability analysis reveals that the proposed Atom Search Optimization-tuned FOPI controller performance is more stable than the particle swarm optimization method. The hardware-in-the-loop implementation is carried out to validate the proposed controller in real-time.