Metaheuristic-tuned PID and fractional-order PID control for photovoltaic systems: a systematic review and benchmarking framework

This systematic review synthesizes intelligent and metaheuristic-based tuning of PID and fractional-order PID (FOPID) controllers in photovoltaic and PV-dominant hybrid energy systems. Classical PID control remains attractive because it is simple and implementation friendly, yet its fixed gains can degrade under nonlinear converter dynamics, irradiance variation, and grid disturbances. Following a PRISMA 2020 workflow, the review screened 226 records and synthesized 79 primary studies published between January 2021 and March 2025, while retaining earlier contextual reviews to frame the field. The revised analysis covers MPPT and converter regulation, inverter current/voltage control, PV-linked ancillary power-quality support, and microgrid stability. Across these layers, intelligent tuning generally improves tracking, damping, robustness, and harmonic performance; however, the credibility of reported gains depends strongly on benchmark fairness, metric transparency, and validation level. The review therefore proposes a concise benchmarking framework to improve reproducibility, comparability, and implementation-oriented interpretation of intelligent PV control studies.