Optimization of time-sharing output Maximum Current Tracking (MCT) strategy in subpanel level Distributed Maximum Power Point Tracking (DMPPT) application

Distributed Maximum Power Point Tracking (DMPPT) has been revealed to be a technique increasing the efficiency and reliability of Photovoltaic (PV) systems in mismatch conditions. To further recover mismatch power loss inside PV panels, subpanel realization of DMPPT solution is developed as an improved penetration of DMPPT concept. This paper proposes a double loop control based subpanel level DMPPT system with a self-adjusted time-sharing Maximum Current Tracking (MCT) algorithm which detects the output current of series connected DC-DC converters. The proposal can always guarantee that all PV units output its individual maximum power regardless of irradiance cases with a greatly reduction of components such as control IC and sensors. Comparing with current commercial panel level solutions, common subpanel level mismatch power loss inside a PV panel can be totally recovered with single current sensor and control IC. The proposal of this paper can be utilized for further integration of PV optimizer.