Conference Proceedings

Permanent URI for this collectionhttps://dspacenew8-imu.refread.com/handle/123456789/1718

Browse

End date: 2019Has files: No

Search Results

Now showing 1 - 10 of 12
  • No Thumbnail Available
    Item
    Influence of Technology in women Entrepreneurship
    (International Seminar on Women Entrepreneurship and Globalization: Issues and Challenges, 2018-02) Ravichandran, N.
  • No Thumbnail Available
    Item
    Evaluation of river regulatory measures in hughly estuary using tidal asymmetry characteristics
    (IEEE, 2006) Sivakholundu, K. M.; Kathiroli S.; Mani J. S.; Idichandy V. G.
    Tidal asymmetry has a profound effect on estuarine hydrodynamics and sedimentation pattern. The information of tidal asymmetry can be a useful tool to evaluate the flow pattern in shallow estuary and characterize the dominance of flood or ebb flow. The effects of features (like obstructions, depressions, etc.) and discharge variation in a theoretical channel section is simulated to quantify the parameters of tidal asymmetry. A set of proposed river regulatory measures in a shallow estuary (Hughly, India) was taken up for evaluation using tidal asymmetry parameters to check whether this may be used as additional tool. The indications provided (flood dominance and hence sediment importing regime) with asymmetry parameters do match with field conditions (based on bathymetry survey data). The asymmetry parameters may be put to use to evaluate the change in flood/ebb dominance in relative terms in a given section.
  • No Thumbnail Available
    Item
    Design of sustainable shore protection solution using geosynthetic tubes
    (GA 2016 - 6th Asian Regional Conference on Geosynthetics, 2016) Kiran, A.; Ravichandran, V.; Jebakumar, P.; Abhishek, T.; Sivakholundu, K. M.
  • No Thumbnail Available
    Item
    Application of parametric acoustics for shallow-water near-surface geophysical investigations
    (IEEE, 2006-05) Vasudevan, Manoj; Sivakholundu, K. M.; Venkata Rao, D.; Kathiroli, S.
    Shallow-water near-surface geophysical investigations were carried out, under two different scenarios - one to assess the status of a pipeline in the West coast and the other to assess the effect of water-injection dredging in the East coast of India. In both these investigations, Parametric Sediment Echo Sounder (SES-2000), a system developed by Innomar Technologie GmbH, which makes use of the parametric acoustical effect, was used. In the former case, profiles were taken across a pipeline at regular intervals to determine whether it was buried or exposed. The parametric system produces a 2D geo-acoustic section in which the pipe is indicated by a hyperbolic curve. The exposed height or buried depth of the pipeline at a crossing is then estimated. This investigation could, also, reveal the geomorphologic changes in the immediate vicinity of the pipeline. In the latter case, parametric acoustics was utilized to provide supplementary results for the assessment of water-injection dredging. Parametric acoustic data could expose the abrupt termination of certain near-seabed layer interfaces and sediment accumulations along steep slope, quite convincingly. SES-2000 proved to be handy to investigate the near-surface sub-seabed, especially in areas where conventional or popular methods find practical difficulties to be carried out.
  • No Thumbnail Available
    Item
    Estimation of performance parameters using charge freed from deep traps located at interfacial region of oil-paper insulation
    (IEEE, 2019-11-21) Mishra, Deepak; Verma, R.; Baral, Arijit; Haque, Nasirul; Chakravorti, Sivaji
    De-trapped charge dislodged from interfacial region of oil-paper insulation can be used as an effective insulation sensitive parameter. Over time, various physiochemical reactions takes place at interfacial region and consequently results in the formation of different trap sites (deep and shallow). Charges which resides at these traps sites are de- trapped after gaining sufficient energy. In present analysis, it is found that charge dislocated from deep traps maintains some specific type of relationship with different insulation sensitive parameters. Before using de-trapped (dislodge from deep traps) as an effective insulation sensitive parameter the effect of geometry must be reduced, as amount of de-trapped charge depends on the area of interfacial region which is not identical for all units. Result presented in this paper shows that use of geometric capacitance for normalization purposes significantly reduces the effects of insulation physical dimensions on de- trapped charge. The capability of deep charge (normalized using dc insulation resistance and geometrical capacitance) is also compared in the present work.
  • No Thumbnail Available
    Item
    Effect of measurement temperature of insulation poles used for assessment of oil-paper insulation
    (IEEE, 2018-12-07) Verma, R.; Mishra, Deepak; Baral, Arijit; Chakravorti, Sivaji
    Analysis of Polarization-depolarization current (PDC) data is a popular technique used for assessing condition of oil-paper insulation. Oil-paper insulation deteriorates with aging during the operational life of the power equipment. In order to get information regarding the insulation condition; different performance parameters are used which can be estimated from PDC data. These parameters include paper moisture (%pm), Dissipation factor (%tanδ) and paper conductivity (σ paper ). In addition to these parameters, insulation poles can also be used for insulation diagnosis. Recently, it has gained popularity in field of insulation diagnosis as it does not depend on physical geometry of insulation. In this paper, the effect of measurement temperature on insulation poles has been analysed. Also, an attempt has been made to establish a relation between insulation poles and other insulation sensitive parameters such as %pm, σ paper and %tan δ.
  • No Thumbnail Available
    Item
    Effect of measurement temperature on interfacial charge freed from deep traps located at the interface of oil-paper insulation
    (IEEE, 2018-12-07) Dey, Debangshu; Sarkar, A.; Pal, Sayantan; Kumar, A.; Mishra, Deepak; Baral, Arijit; Haque, Nasirul; Chakravorti, Sivaji
    Accumulation of interfacial charge creates local field distortion during insulation response measurement. Furthermore, such localized field enhancement affects the interaction between polar compounds present within oil-paper insulation and in turn affects its aging process. By getting sufficient trap energy (normally by thermal oscillation) these trapped charges dislocate from their locations and contribute in depolarization current. These interfacial charges include charges dislocated from shallow and deep sites at interfacial region. The charge residing at deep locations takes more time to dislodge themselves compared to charge residing at shallow sites. As dipole present in cellulose has large relaxation time, there might be some relation between deep charge and paper insulation sensitive parameters. In this work, effects of temperature on deep traps are analyzed. Results reported in this paper shows that magnitude of charge freed from deep locations maintains a correlation with measurement temperature and paper conductivity.
  • No Thumbnail Available
    Item
    Feasibility of using normalized de-trapped charge for diagnosis of power transformer insulation
    (IEEE, 2018-10-07) Mishra, Deepak; Baral, Arijit; Haque, Nasirul; Chakravorti, Sivaji
    In order to use de-trapped interfacial charge as a performance parameter for diagnosis, it is necessary to reduce the influence of insulation geometry. Available literature shows that this can be done by considering dc insulation resistance R 0 as the normalization factor. Such normalization may not be always practically feasible as information regarding R 0 requires measurement of temperature sensitive low amplitude current. In this paper it is shown that geometric capacitance C 0 (instead of R 0 ) can be used as an effective normalization parameter to reduce effect of insulation geometry. Effect of normalizing freed interfacial charge using C 0 and R 0 and its subsequent effect on insulation diagnosis are presented in this paper.
  • No Thumbnail Available
    Item
    Effect of interfacial charge on parameters considered for insulation diagnosis of power transformer
    (IEEE, 2017-12-02) Mishra, Deepak; Baral, Arijit; Pradhan, Arpan Kumar; Haque, Nasirul; Chakravorti, Sivaji
    Out of various analysis methods available Polarization Depolarization Current (PDC) measurement is extensively used for monitoring of oil-paper insulation health. In such case, Classical Debye Model (CDM) is used for analysis of recorded PDC data. CDM has limited capacity to simulate the effect of interfacial charge. Due to this interfacial charge, nonlinearity arises in the system which adversely affects the insulation. Conductivity difference between oil and paper is the main reason behind this interfacial charge which creates nonlinearity in system. In the present work, the effect of interfacial charge is analyzed on some of the performance parameters used for diagnosis of insulation like peak value of return voltage spectrum and paper conductivity.
  • No Thumbnail Available
    Item
    Effect of charge accumulated at oil-paper interface on zero of transfer function formulated using classical debye model parameters
    (IEEE, 2017-11) Mishra, Deepak; Pradhan, Arpan Kumar; Baral, Arijit; Haque, Nasirul; Chakravorti, Sivaji
    PDC measurement and analysis is one of widely used tool for reliable diagnosis of power transformer insulation. In different reported methods of analysis it is considered that polarization current is composed of the current due to dipole movement and conduction current. Similarly the depolarization current is assumed to be composed of relaxation of dipoles. However when the dc conduction effect is removed from polarization current it is found the resulting current is not similar to the measured depolarization current. This deviation in both the currents show the presence of nonlinearity in the system. This nonlinearity arises due to migration of trapped charges that reside at the interfacial region of oil-paper insulation. The present paper shows the effect of such free charge on some important performance parameters like paper moisture and zero of Transfer Function of Classical Debye Model.