The power output of the photovoltaic(PV) system having multiple arrays gets reduced to a great extent when it is partially shaded due to environmental hindrances. The maximum power trackers which are conventionally us...The power output of the photovoltaic(PV) system having multiple arrays gets reduced to a great extent when it is partially shaded due to environmental hindrances. The maximum power trackers which are conventionally used may not be competent enough to find the maximum power point(MPP) during partially shaded conditions. The sensible reason for the failure of conventional trackers is during partial shaded conditions the PV arrays exhibit multi peak power curves, thereby making simple maximum power point tracking(MPPT) algorithms like perturb and observe(P&O) to get stuck with local maxima instead of capturing global maxima.Therefore, global search MPPT aided by evolutionary and swarm intelligence algorithms will be conducive to find global power point during partially shaded conditions. This work suggests a unified controller which feeds control signal to its power electronic conditioner placed at each module. The evolutionary algorithm which is taken into consideration in this work is differential evolution(DE).The performance of the proposed method is compared to the classical un-dimensional search controller and it is evident from the Matlab/Simulink results that the unified controller prevails over the distributed counterpart.展开更多
The Sodium Montmorillonite(Na-MMT)is not susceptible to polymer due to its organophilic character and low basal spacing.The primary objective of this study was to improve Na-MMT platelets separation by organically mod...The Sodium Montmorillonite(Na-MMT)is not susceptible to polymer due to its organophilic character and low basal spacing.The primary objective of this study was to improve Na-MMT platelets separation by organically modifying it with cation and anion exchanges using Cetyl trimethyl ammonium bromide(CTAB)and Sodium dodecyl sulfate(SDS)respectively.Basal spacing,presence of functional groups,Zetapotential with particle size analysis and thermal stability of the Organomodified Na-MMT(OMMT)were characterized using XRD,FTIR,zeta-potential analyzer and TGA respectively.The basal spacing of CTAB modified OMMTincreased to 19.5Åfrom 11.0Åwhich corresponds to the basal spacing of Na-MMT.The SDS modified OMMT did not show any increase in the basal spacing.FTIR spectra of CTAB modified Na-MMT illustrated the attachment of CTAB functional groups to Na-MMT,while the same was absent in the case of SDS modified Na-MMT.The zeta-potential of Na-MMT shifted from–24.88 mV to 15.66 mV in the case of CTAB modified Na-MMTand 12.49 mV for SDS modified Na-MMT,indicating a greater surface potential of the modified nanoclay.The TGA showed greater weight loss for CTAB modified Na-MMT than that for Na-MMT,indicating the effective Na+ion exchange with alkyl amines.展开更多
文摘The power output of the photovoltaic(PV) system having multiple arrays gets reduced to a great extent when it is partially shaded due to environmental hindrances. The maximum power trackers which are conventionally used may not be competent enough to find the maximum power point(MPP) during partially shaded conditions. The sensible reason for the failure of conventional trackers is during partial shaded conditions the PV arrays exhibit multi peak power curves, thereby making simple maximum power point tracking(MPPT) algorithms like perturb and observe(P&O) to get stuck with local maxima instead of capturing global maxima.Therefore, global search MPPT aided by evolutionary and swarm intelligence algorithms will be conducive to find global power point during partially shaded conditions. This work suggests a unified controller which feeds control signal to its power electronic conditioner placed at each module. The evolutionary algorithm which is taken into consideration in this work is differential evolution(DE).The performance of the proposed method is compared to the classical un-dimensional search controller and it is evident from the Matlab/Simulink results that the unified controller prevails over the distributed counterpart.
文摘The Sodium Montmorillonite(Na-MMT)is not susceptible to polymer due to its organophilic character and low basal spacing.The primary objective of this study was to improve Na-MMT platelets separation by organically modifying it with cation and anion exchanges using Cetyl trimethyl ammonium bromide(CTAB)and Sodium dodecyl sulfate(SDS)respectively.Basal spacing,presence of functional groups,Zetapotential with particle size analysis and thermal stability of the Organomodified Na-MMT(OMMT)were characterized using XRD,FTIR,zeta-potential analyzer and TGA respectively.The basal spacing of CTAB modified OMMTincreased to 19.5Åfrom 11.0Åwhich corresponds to the basal spacing of Na-MMT.The SDS modified OMMT did not show any increase in the basal spacing.FTIR spectra of CTAB modified Na-MMT illustrated the attachment of CTAB functional groups to Na-MMT,while the same was absent in the case of SDS modified Na-MMT.The zeta-potential of Na-MMT shifted from–24.88 mV to 15.66 mV in the case of CTAB modified Na-MMTand 12.49 mV for SDS modified Na-MMT,indicating a greater surface potential of the modified nanoclay.The TGA showed greater weight loss for CTAB modified Na-MMT than that for Na-MMT,indicating the effective Na+ion exchange with alkyl amines.
