Performance Benchmark of Bypassing Techniques for Photovoltaic Modules

The deployment of solar photovoltaic (PV) systems is increasing. The performance degradation of PV systems can happen, which is potentially induced by partial shading, also referred to as mismatch faults. Conventional PV modules are connected in series and are sensitive to mismatch faults. Bypass methods and other solutions are thus used to reduce the mismatch effect. This paper compares the performances of the bypassing techniques using traditional (Schottky) bypassing diodes with smart bypassing diodes (SBD). The benchmarking results show that the SBD can be employed to improve the performance during shading in PV systems. More specifically, the use of SBDs with series-connected MOSFETs leads to a reduction of the reverse voltage with a higher output power under various shading conditions, when compared to the case with traditional bypassing diodes. The reduction in the reserve voltage contributes to lowered temperature in shaded cells, and thus increases the reliability of the PV modules.