Work

Multi-Objective Fractional-Order Control Design for Solar Collector Systems Under Parameter Perturbations and Stability Constraints

Year: 2026

Type: article

Abstract: The primary objective of a parabolic distributed solar collector system (P-DSCS) is to regulate fluid heat generation so that it tracks a reference trajectory despite non-uniform solar irradiance. Fractional-order proportional-integral-derivative (FOPID) controllers offer superior dynamic flexibility to handle these complex thermal transients. However, existing tuning strategies for P-DSCS collapse frequency-domain requirements into an optimization problem solved by standard algorithms, masking critical trade-offs between competing performances and omitting closed-loop stability verification. To overcome these limitations, this paper presents an original multi-objective optimization framework for FOPID controlled P-DSCS. The tuning problem is formulated as a three-objective Optimization Problem that simultaneously minimizes phase-margin slope sensitivity for iso-damping robustness, peak sensitivity for low-frequency disturbance rejection, and complementary sensitivity for high-frequency noise attenuation. The Multi-Objective Imperialist Competitive Algorithm (MOICA) extracts a three-dimensional Pareto front, offering optimal control trade-offs. Comparative simulations against PID and literature algorithms (Multi-objective Particle Swarm Optimization (MOPSO) and Non-dominated Sorting Genetic Algorithm II (NSGA-II)) validate the superior performance of the MOICA-FOPID framework. MOICA consistently outperforms all algorithms across all metrics, improving iso-damping robustness by 38.99%. It also reduces high-frequency noise by 25.66%, while enhancing low-frequency disturbance rejection by 10.87%. Moreover, the optimal MOICA-FOPID controller maintained superior robustness despite P-DSCS gain and time-constant fluctuations.

Source: Fractal and Fractional

DOI: 10.3390/fractalfract10100707

Authors: Abdullah Alghafis, Mohamed Nejlaoui

Institution: Qassim University

Language: English

Topic: Advanced Control Systems Design

Subfield: Control and Systems Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: gold

Estimated APC paid: $3,258