Faculty Publications

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    A Novel Islanding Detection Technique Based on Piezoelectric Sensors for Grid-Integrated DG Systems
    (Taylor and Francis Ltd., 2023) Kulkarni, S.V.; Hegde, V.; Gaonkar, D.N.
    This paper presents the novel islanding detection technique that depends on the piezoelectric sensors for distributed generation sources (DGs) in the grid-integrated operation mode. The islanding detection method employs a piezoelectric sensor for the detection of the frequency variations during grid disruptions. The designed diaphragm-based sensor has a natural frequency as that of the fundamental frequency of the system frequency signal. Any further deviations from the natural frequency due to the disturbances will be sensed by the sensor and a control signal is being sent to the associated circuit breaker for suitable action. The sensor structure is modeled using the finite element method and implemented in the Phase-Locked Loop (PLL) of the grid-integrated DGs. The proposed circular diaphragm-based sensor structure will have the bandwidth in the range of natural frequency with the tolerance rate of ±1% and uses the input signal received from the PLL controller outer loop. The proposed islanding detection technique’s performance and reliability for grid-integrated DG are validated using the real-time hardware in the loop test-bed platform. The HIL virtual simulated responses show that the method can be proposed effectively for islanding detection in the event of frequency variations in the grid-integrated DG systems. © 2023 IETE.
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    Synthesis, Photophysical, and Computational Studies of Mono-Azo-Bridged, Meso-Tris(2-Furyl/2-Thienyl) Substituted Porphyrin-Arene Hybrids
    (John Wiley and Sons Inc, 2024) Nagesh Shet, S.; Ganesh Bhat, V.; Hegde, V.; Hegde, G.; Udayakumar, U.; Shetti, V.S.
    Porphyrins hybrids have been used as models to study various energy/electron transfer processes. The linkers connecting various subunits in such hybrids are vital in establishing good electronic communication between the subunits and the azo-bridge can be one of the efficient linkers to do so. Despite of these, the mono azo-bridged porphyrin-arene hybrids reported in the literature are only handful and the methods used to create them are not that efficient. In addition, the porphyrins used in this field so far contains only six-membered meso-substituents. By keeping these points in mind, we have developed a mild, one-pot, work-up-free, high-yielding method to synthesize mono-azo-bridged, porphyrin-arene hybrids which also features porphyrins containing three five-membered substituents like 2-furyl or 2-thienyl on their meso-positions. Along with the NMR and mass characterizations, the photophysical and computational studies of all the reported hybrids are presented. The hybrids containing meso-tris(2-furyl/thienyl) substituted porphyrins displayed red-shifted absorption and emission bands compared to their all-meso-aryl-containing counterparts. In general, all the hybrids displayed enhanced fluorescence quantum yields compared to their precursor porphyrins. Among the series, the meso-tris(2-furyl) substituted porphyrin-arene hybrids exhibited the more significant Stokes shift and small bandgap. The computational studies were in good agreement with the experimental findings. © 2024 Wiley-VCH GmbH.