| Work Detail |
Researchers at Delft University of Technology (Netherlands) have made a first attempt to validate reconfigurable solar modules using prototypes in outdoor tests. The panels consist of two or more solar cell blocks connected to a switching array and reportedly achieve 10.2% higher energy efficiency than conventional shade-resistant modules under partial shading conditions.
A group of researchers at Delft University of Technology in the Netherlands has developed a new design of reconfigurable photovoltaic modules that can reportedly provide 10% higher energy performance than conventional shade-resistant photovoltaic panels with interconnections. fixed and six bypass diodes in partial shading scenarios.
“Normally, a reconfigurable photovoltaic module consists of two or more solar cell blocks connected to a switching array,” the scientists explain. “The matrix switcher can dynamically modify the electrical interconnections between the blocks based on lighting conditions and maximize the power output of the module.”
In the study “ Electrical performance of a fully reconfigurable series-parallel photovoltaic module ,” published in Nature Communications, the research group states that their work represents the first attempt to validate modules reconfigurable through prototypes installed under realistic operating conditions.
The academics implemented a switching matrix with MOSFETs that, according to them, allows the module to adopt 27 different series-parallel electrical configurations. These are classified as s1p6, s2p3, s3p2 and s6p1, the first number indicating how many blocks are connected in series forming a chain, and the second number indicates how many chains of blocks connected in series are connected in parallel.
The scientists said they could identify the best module configuration taking into account lighting conditions using a synchronous reconfiguration algorithm, which measures the short-circuit current of all six cell blocks.
“When the PV module is uniformly illuminated, the s6p1 configuration is chosen, as it provides the lowest current and minimizes Joule losses,” they explain. “On the other hand, when the PV module is partially shaded, configurations with blocks interconnected in parallel will be chosen to reduce current mismatch losses.”
The team compared the performance of a prototype reconfigurable panel with that of a reference panel with fixed interconnections for four months under different shading conditions. “Different bar lengths were used to progressively shade and unshade the blocks during sunrise and sunset.”
Tests showed that, without any shading, the reference panel produced 1.9% more power than the reconfigurable module due to additional resistive losses in the latters switching matrix. In contrast, the reconfigurable PV module produced between 4.8% and 13.7% more energy than the reference panel under shading conditions, and an average higher performance of 10.2%.
The group specified that the performance of the reconfigurable module does not include the power consumed by the matrix switcher and sensing circuits.”
“During all shading experiments, about 40% of the power was supplied by the s1p6 configuration, in which all six cell blocks are connected in parallel,” the researchers stated. Although s1p6 is the most shadow-tolerant of the 27 possible configurations, it is also the one that generates the highest currents and therefore can cause the greatest system-level losses.”
Looking ahead, they said they want to test asynchronous algorithms and use a microcontroller in the smart junction box. |
