The prime objective of this research study was the investigation the new natural cellulosic fiber extracted from the stem of Abutilon Indicum plants as an alternative reinforcement in greener composite materials for structural applications. Abutilon Indicum a flowering plant with unique medicinal values are abundantly found in India and other south Asian countries. The fibers extracted from the stem of the Abutilon Indicum plant are proven to be sustainable, ecofriendly, and novel and hence this fiber is chosen for characterization study. In this experimental investigation the physical, chemical, thermal, morphological, crystallinity, chemical constituents, and surface characteristics of raw Abutilon Indicum fibers (AIF) were analyzed. Chemical analysis results convey the presence of higher cellulose content of (56.12 wt.%) in AIF. The diameter (175 μm) and density (1.170 g/cm3) of AIFs are determined by physical analysis of the raw fibers. Such lower density values observed in AIF make it as a perfect material for lightweight applications. Crystalline properties of AIFs are determined from X‐ray diffraction tests with a crystalline index of 77.35%, and crystalline size of 2.20 nm, which attributes to the presence of cellulose‐1β and the crystallites are ordered in nature. Thermal stability of 175°C, maximum degradation temperature upto 302.6°C and kinetic activation energy of 86.95 kJ/mol of AIF are established based on thermo gravimetric analysis. Morphological and surface characteristics of AIF through a scanning electron microscope (SEM) and atomic force microscope (AFM) analysis revealed that the raw fibers display a relatively finer surface. Research findings of the AIF mentioned above conclude that the AIFs prove to be an ideal, alternative reinforcement in greener composite materials for sustainable and cleaner production of components in structural applications.

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This paper presents a novel approach for the power transformer differential protection based on empirical Fourier transform (EFT). The EFT is a novel transform technique, which is derived from discrete Fourier transform (DFT) with certain modifications based on the nature of current waveforms during internal fault, inrush and current transformer (CT) saturation. The fundamental component estimated by EFT is equal to DFT estimation for internal fault currents and zero or very low value for inrush currents and CT saturation currents. The fundamental component estimated by EFT is used in the biased restraint characteristic with a deviation factor (DF) to make tripping decisions for relays. The DF describes the waveform deviation rate of differential current waveform from a pure sinusoidal waveform. The proposed EFT based differential protection algorithm (EFT-DPA) is validated and compared with the conventional DFT based differential protection algorithm (DFT-DPA) through modeling for an existing real time power transformer in Tamil Nadu Transmission Corporation Limited (TANTRANSCO), Tamilnadu, India. Also, the performance of the EFT-DPA is investigated with the fault recorder data taken from the field differential relay of the same power transformer. The power transformer modeling is carried using PSCAD and the EFT-DPA is implemented in MATLAB. Index Terms-Powertransformer differential protection, Fourier transform, internal fault, inrush current, CT saturation. M. Senthil Kumar received the B.E. degree in electrical and electronics engineering, and the M.E.

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