Browsing by Author "Madhavan, J."

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Engineering of cobalt impregnated sponge like spinel nickel ferrite as an efficient electrocatalyst for sustained overall water splitting
    (Elsevier B.V., 2025) Benny, S.; Galeb, W.; Ezhilarasi, S.; Rodney, J.D.; Udayashankar, N.K.; Raja, M.D.; Madhavan, J.; Arulmozhi, S.
    The substantial exhaustion of energy resources in the present reality limelight to the exigency for a clean and sustainable energy resource and the key solution for this would be electrocatalytic water splitting to produce clean H2. For achieving this objective amending noble metals with non-noble metals as electrocatalysts which are cost effective and earth abundant would serve as a better option. Herein, combustion derived nickel ferrite (NiFe2O4) and cobalt doped nickel ferrite (NiCoxFe2-xO4) nanoparticles were extensively studied for Oxygen (O2) and Hydrogen (H2) evolution reactions respectively. The NiCo0.01Fe1.99O4 and NiCo0.03Fe1.97O4 Co-doped NiFe2O4 electrocatalyst exhibits excellent Hydrogen Evolution Reaction (HER) and Oxygen Evolution Reaction (OER) activity in 1.0 M KOH electrolyte requiring a potential of 1.68 V (? = 455 mV) vs RHE for OER and ?0.167 V (? = 167 mV) vs RHE for HER to achieve the benchmark current density of 10 mA cm?2 and ?10 mA cm?2 for OER and HER respectively. The best performing electrodes (NiCo0.03Fe1.97O4
  • No Thumbnail Available
    Item
    Modified Selective Harmonics Mitigation PWM for a Switched Diode Multilevel Inverter
    (IOP Publishing Ltd, 2021) Sahaya Ponrekha, A.; Jagabar Sathik, J.; Lakshmanan, P.; Singh, J.; Mani, L.; Mandal, A.; Madhavan, J.
    A modified selective harmonic mitigation (SHM) technique for multilevel inverters considering the RMS output voltage magnitude is presented. The harmonic contents in the output voltage of these inverters must satisfy the specified grid code requirement standards. In conventional SHM techniques, the firing angles of the multilevel inverters have been derived by taking into account grid code harmonic reduction standards. When the multi-level inverters are driven with these firing pulses generated, it results in reduction of the magnitude of the inverter output voltage. In order to overcome this issue of output voltage reduction, the modified SHM optimization problem includes another constraint on the RMS output voltage limits, which results in different set of firing angles. This facilitates the use of firing angles, which takes into account the grid code standards of harmonic mitigation without compromising the value of the RMS output voltage of the inverters. The proposal has been simulated and validated in MATLAB Simulink and the experimental results are obtained for a single-phase seven level inverter with Silicon made semiconductor switches. By using the proposed method, output voltage THD (upto 40th harmonics were considered) of 5.9% was obtained, which is well below the harmonic standards specified by EN 50160. © 2021 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited.