TITLE:
Optimization of P & O MPPT Tracking under Thermal Constraints: Sensitivity Analysis of the Perturbation Step ΔD for a PV-Boost System
AUTHORS:
Sada Traore, Moustapha Thiame, Ansoumane Diedhiou, Modou Tine
KEYWORDS:
P & O MPPT, Sensitivity Analysis, Perturbation Step ΔD, Boost Converter, Thermal Constraints, MATLAB/Simulink
JOURNAL NAME:
Modern Mechanical Engineering,
Vol.16 No.3,
July
31,
2026
ABSTRACT: This paper presents a detailed optimization of the Perturb and Observe (P & O) Maximum Power Point Tracking (MPPT) algorithm applied to a 250 W photovoltaic module connected to a DC-DC Boost converter. The main contribution lies in a systematic sensitivity analysis of the perturbation step size (ΔD) under severe thermal constraints ranging from 25˚C to 70˚C. The PV module was modeled using the single-diode equivalent circuit, while the Boost converter was designed and simulated in Continuous Conduction Mode (CCM) using the averaged state-space approach in MATLAB/Simulink. Simulation results demonstrate that the choice of ΔD is critical: a too-small step (ΔD 2.5 s), whereas a too-large step (ΔD > 0.015) causes significant steady-state oscillations and reduces tracking efficiency below 92%. The optimal perturbation step ΔD = 0.005 achieves an excellent compromise, providing an average tracking efficiency of 96.80% and a convergence time of 1.2 s. Compared to open-loop control with fixed duty cycle, the optimized P & O MPPT delivers an average power gain of +25.6%, reaching up to +39.3% at 25˚C.