A Multi-Layer Control System for Solar Power Optimizers: Integrated I-V Curve Scanning and Overvoltage Protection

Solar Power Optimizers (SPOs) offer significant potential for improving photovoltaic (PV) system performance by addressing module mismatch and partial shading challenges. This paper introduces an innovative multi-layer control system for series-connected SPOs that extends beyond traditional SPOs by integrating diagnostic and protective capabilities. Utilizing a Four-switch Buck-Boost converter topology, the proposed system implements an approach for I-V curve scanning and overvoltage protection across multiple photovoltaic modules. The research develops two distinct overvoltage protection controllers: one for the I-V curve scanning process and another for partial shading conditions, with a wireless communication protocol enabling seamless data exchange between modules and overcoming connectivity challenges in series-connected configurations. Experimental validation is conducted on a prototype system, demonstrating the method’s effectiveness in maintaining maximum power point tracking (MPPT), extracting I-V curves, and preventing voltage stress under varying operating conditions. The system captures detailed module performance, ensures stability, and enhances diagnostic and reliability through advanced control strategies, offering a cost-effective solution for solar energy system performance and maintenance.