RESUMO
A new fifteen-level stepped DC to AC hybrid converter is proposed for Solar Photovoltaic (SPV) applications. A boost chopper circuit is designed and interfaced with the fifteen-level hybrid converters specific to Electric Vehicles' Brushless DC Motor (BLDC) drive systems. In chopper units, the output of solar panels is regulated and stepped up to obtain the nominal output voltage. In the stepped DC-link hybrid converter configuration, fifteen-level DC-link voltage is achieved by the series-operated DC-link modules with reduced electrical energy compression. From the comprehensive structure, it is anecdotal that the proposed topology has achieved minimum switching and power loss. Elimination of end passive components highlights the merits of the proposed hybrid systems. The reduction of controlled power semiconductor switches and gate-firing circuits has made the system more reliable than other hybrid converters. From the extensive analysis, the experimental setup has reported that 7% reduction in harmonics and a 54% reduction in controlled power switches than the existing fifteen-level converter topologies. Mitigation of power quality issues in the voltage profile of a fifteen-level multilevel hybrid converter is achieved through the implementation of dsPIC digital-controller-based gate triggering circuits.
RESUMO
In the present study, the n-SnO2/p-CuFe2O4 (p-CFO) complex was prepared by a two-step process. p-CFO synthesized by the molten salt method was coated with SnO2 synthesized by a facile in situ chemical precipitation method. The formation of n-SnO2/p-CFO was confirmed by powder X-ray diffraction (PXRD). Scanning electron microscopy (SEM) images showed that the sharp edges of uncoated pyramid-like p-CFO particles were covered by a thick layer of n-SnO2 on coated p-CFO particles. The complete absence of Cu and only 3 wt% Fe on the surface of the n-p complex observed in the elemental analysis using energy-dispersive X-ray spectroscopy (EDX) on the n-p complex confirmed the presence of a thick layer of SnO2 on the p-CFO surface. Diffuse reflectance spectroscopy (DRS) was employed to elucidate the bandgap engineering. The n-SnO2/p-CFO complex and p-CFO showed 87% and 58.7% methylene blue (MB) degradation in 120 min under sunlight, respectively. The efficiency of the n-p complex recovered after 5 cycles (73.5%) and was found to be higher than that of the uncoated p-CFO (58.7%). The magnetically separable property of the n-p complex was evaluated by using vibration sample magnetometry (VSM) measurements and it was confirmed that the prepared photocatalyst can be easily recovered using an external magnet. The study reveals that the prepared complex could be a potential candidate for efficient photodegradation of organic dyes under sunlight due to its efficient recovery and reusability owing to its magnetic properties.
RESUMO
As a renewable and sustainable energy source and an alternative to fossil fuels, solar-driven water splitting with photoelectrochemical (PEC) cell is a promising approach to obtain hydrogen fuel with its near-zero carbon emission pathway by transforming incident sunlight, the most abundant energy source. Because of its importance and future prospects, a number of architectures with their own features have been formed by various synthesis and growth methods. Because the materials themselves are one of the most dominant components, they determine the solar-to-hydrogen efficiency of the PEC cells. Thus, several representative PEC cells were reviewed by categorizing them as per synthesis and/or growth methods such as physical vapor deposition, chemical vapor deposition, electrochemical deposition, etc. This review provides researchers with an overview and acts as a guide for research on solar-driven water splitting PEC cells.
