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A new method for islanding and non-islanding disturbances detection and classification is proposed for a multiple PV based distributed generation (DG) system utilizing adaptive multi-scale morphological filter (AMF) and random vector functional link network (RVFLN) classifier. In comparison to different signal analysis techniques, the mathematical MF, that has wide application in power signals, EEG signal analysis, image processing, pattern recognition, etc. posses the benefit of easy execution, fast processing, and minimal computations. Further it is well known that a single scale morphological filter has limited noise filtering capacity and may also filter useful signal disturbance components resulting in erroneous detection of disturbance signals in microgrid. Therefore, an adaptive multiscale combined morphological filter is presented in this paper built on the concept of multiscale overall filtering which has better denoising effect and can retain useful signals better than the traditional filter. The proposed technique is built upon the measurement of voltage signal samples and the processing of these signals through AMF has been done for feature extraction. The extracted features are then employed as inputs to an efficient, fast, and easily implementable randomized network based classifier (RVFLN) which is made robust to reject the presence noise and outliers in the signal data. The outputs exhibited from the suggested technique concludes that it is s very fast and accurate technique for the detection and classification of islanding and non-islanding events in comparison to the widely used approaches. [ABSTRACT FROM AUTHOR]

Single phase nano-crystalline zinc ferrite (ZnFe2O4) thin films were deposited on fused quartz substrate using the pulsed laser deposition technique. The films were deposited at different substrate temperatures. The field dependence of magnetization at 10 K shows hysteresis loops for all the samples. Temperature dependence of the field cooled (FC) and zero field cooled (ZFC) magnetization indicated irreversible behavior between the FC and ZFC data, and the irreversibility depends on the measuring magnetic field. The thermo-magnetic irreversibility in the magnetization data is correlated with the magnitude of the applied field and the coercivity (HC) obtained from the M-H loops. [ABSTRACT FROM AUTHOR]

MnFe2O4 thin films were pulsed laser deposited on to quartz substrate from room temperature (RT) to 650 °C in a pure argon environment. Temperature dependence of spontaneous magnetization (4πMS) was measured on these films from 10 K to 350 K using a vibrating sample magnetometer. Ferromagnetic resonance (FMR) study was also carried out at 300 K. The exchange stiffness constant (D) values were obtained by fitting the 4πMS data to the Bloch’s equation. The D values of the films thus found decreases while the 4πMS value increases, though non-monotonically, with the increase in TS and tend to reach bulk values at TS = 650 °C. The variation in D and 4πMS values of the films are explained based on the degree of inversion and oxidation state of cations in thin films. [ABSTRACT FROM AUTHOR]

Stoichiometric and non stoichiometric magnesium ferrite (MgFe2+δO4, δ=0.0, 0.1) were synthesized by the sol gel combustion method resulting in nanocrystalline powders with size ranging from 10 to 100nm. These powders were calcined at various temperatures (300-800°C). One part of the calcined powder was quenched in liquid nitrogen and the other part furnace cooled. α-Fe2O3 was observed in all calcined samples by XRD and this was also reflected in the magnetization data. Electrical response of MgFe2.1O4+δ spinel phase to 75ppm ethanol was found to be greater than that for a stoichiometric magnesium ferrite. [ABSTRACT FROM AUTHOR]