A Fixed Zone Perturb and Observe MPPT Technique for a Standalone Distributed PV System

This article proposes a fixed zone perturb and observe (FZPO) technique to achieve improved steady-state efficiency and a fast and drift-free maximum power point tracking (MPPT) for photovoltaic (PV) systems without any additional sensors. In this technique, the PV array’s power–voltage (P–V) curves are divided into multiple zones with unique zone boundary voltages for different irradiance conditions. This technique employs a combination of adaptive and fixed step sizes to improve the performance, where the adaptive step size is calculated from simple mathematical equations, resulting in a reduced computational burden. Besides, natural drift-free tracking is achieved without any additional sampling or computation, overcoming existing techniques’ limitations. The FZPO technique requires a PV panel’s information only at the initial design stage but not during real-time tracking, making the implementation possible using only low-cost processors. This article presents the implementation and design of the proposed controller. The FZPO technique’s performance is validated through a comprehensive set of hardware experiments on a buck–boost full-bridge (BBFB) converter under various irradiance conditions per the EN50530 standard. For a step change in irradiance, the FZPO technique is experimentally verified to be 42% and 20% more efficient than the conventional and VSS techniques, respectively. During the irradiance varying conditions using the FZPO technique, the peak power loss is one-sixth compared to the conventional and VSS techniques. Practical field-related considerations, such as PV panel temperature effects, are further investigated through experiments.