Prathap Basappa
Norfolk State University
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Publication
Featured researches published by Prathap Basappa.
IEEE Transactions on Dielectrics and Electrical Insulation | 2007
Prathap Basappa; Sang-Dong Jang; Jaehwan Kim
The concept of using cellulose as a smart material for preparing electro-active paper (EAPap) has been a land mark discovery, since it exhibits an impressive magnitude of actuation at relatively modest voltages. Considering the small thickness of cellulose samples (35 mum) and smaller depth of electrodes (100 nm), even at relatively low operating voltages (7 V), high electrical stresses can exist at pointed asperities on electrode surface, non-uniform locations in cellulose structure and at triple points joining electrode, cellulose and air. This paper reports the results of our AC and DC breakdown tests on cellulose samples carried out according to ASTM standards. The variation of breakdown strengths with relative humidity levels has been investigated and the results are explained with the aid of Maxwell-Wagner effect.
conference on electrical insulation and dielectric phenomena | 2001
Prathap Basappa; V. Lakdawala
Partial discharges (PD) have been traditionally used to monitor tree growth in electrical insulation. In this work perspex (PMMA) samples with a needle plane gap have been aged with an AC voltage. The tree growth is monitored simultaneously with collection of PD at regular intervals of time and micro photographing without interrupting the aging voltage. The partial discharge pulse amplitude records are clustered together into groups of class intervals. The first four moments of the PD pulse amplitude distribution are determined and the type of distribution is identified based on. these moments. An algorithmic representation of the /spl beta//sub 1/ and /spl beta//sub 2/ plane is used to identify the distribution type. A complete program is developed which identifies the type of distribution and the parameters. The PD quantities pertaining to bush and branch type trees are analyzed within this framework. The results of the work are presented.
ieee international symposium on electrical insulation | 2008
Prathap Basappa; V.K. Lakdawala; Ashutosh Mishra
Overhead insulators used for transmission lines rated 500 kV and above, are relatively long, and the voltage distribution along the insulator length generally is non-uniform. Even though contamination of the outdoor insulator due to pollution is one of the prime factors leading to flashover and the resulting transmission line faults, it has been observed that the flashover can occur even before the presence of actual contaminants. In practice, the presence of water droplets over the insulator surface creates locations of high electric field intensity, a region where the electrical breakdown can initiate. The degree of field intensification at the triple point between water, air and insulator is a function of the wettability of the insulator surface, which increases with insulator degradation. In this work, the variation of electric field distribution around a typical water droplet in the sheath and shed regions as a function of the contact angle is reported. Two types of commonly used insulating materials namely hydrophobic silicone rubber (SIR) and porcelain have been investigated in our study.
conference on electrical insulation and dielectric phenomena | 2000
Prathap Basappa; V.K. Lakdawala
Experiments were conducted to investigate whether the electrical tree growth in PMMA (polymethylmethacrylate) could be characterized by the partial discharges (PD) that evolved during its progress. PMMA samples with a needle-plane gap were aged under 50 Hz AC voltage, which gave rise to branch and bush type trees. The PDs were collected for a constant duration at regular intervals of times continuously all through the aging sequence. The tree growth was monitored by taking the microphotographs periodically, without interrupting the aging voltage. The parameters of the PD amplitude distributions obtained during the growth were analyzed later by correlation and spectral analysis methods.
ieee international symposium on electrical insulation | 2010
Anusha Jambula; V.K. Lakdawala; Prathap Basappa
The present work contributes for an extensive research of physical electrode systems namely axi-symmetric and non-uniform field systems. In an attempt to optimize the dimensions of the electrode system for subsequent use in electrical measurements, such as electroluminescence, capacitance and conduction current, field values at key points (sharp edges and triple junctions) in an axi-symmetric electrode system are simulated as a function of clearances between low voltage and guard electrodes. The configurations simulated, results, analyses and configurations for an optimal design are presented. The hemispherically capped rod-plane gap has been thoroughly used for studies on breakdown characteristics of gaseous dielectrics. In this study, influence of a dielectric barrier on the electric field and potential distributions in a vertically arranged rod-plane gap was numerically analyzed by using 3D BEM field software. Maximum field intensities and their occurrence in the electrode system were examined for different gap distances, applied potentials, and positions of the barrier between electrodes for estimating the discharge phenomena. The results of the field computation show how the maximum electric field varies in small air gaps with thin insulating barriers. There is a good agreement between the values computed with BEM and other methods reported in literature.
ieee international symposium on electrical insulation | 2010
Prathap Basappa; V.K. Lakdawala
Presence of water droplets over the insulator surface enhances the electric field intensity and leads to electrical breakdown. Water droplets/films lead to the breakdown of the insulator even under the absence of actual contaminants. The objective of this work is to study the effect of water droplets/films in causing an electrical breakdown on practical insulator at various levels of hydrophobicity. This is done by investigating the electric field distribution around the water droplets/films on a model insulator for the shed and sheath configurations by varying the material of the insulator and the contact angles. Effect of deterioration of the hydrophobicity on field distribution is investigated through placing multiple droplets/films on the sheath and shed regions of practical insulator configurations. The results of our simulations and their practical implications are discussed.
conference on electrical insulation and dielectric phenomena | 2008
Prathap Basappa; V.K. Lakdawala
Presence of water droplets over the insulator surface enhances the electric field intensity and leads to electrical breakdown. This is important for outdoor insulation because the combination of moisture and contamination causes flashover at operating voltage; hence affects reliability of power delivery. Electric field has been calculated on insulating surfaces for different patterns of wetting. Simulations have been conducted by varying the number of water droplets, their relative positions and contact angle on the insulator surface in the sheath region. They are simulated using a 3D Electric Field Analysis computer package (Coulomb). One important outcome of this work, is that location of the water droplets with respect to electrodes and other droplets are crucial in determining the maximum E-Field intensity and hence the flash over voltage.
electrical insulation conference | 2013
Anil B. Poda; Prathap Basappa; Christopher S. Fritzel
Literature indicates that introduction of Nano fillers into PP films will improve its electrical characteristics, such as the PD resistance, breakdown strength and loss factor [1]. Some dielectric properties of Nano filled polymers have shown remarkable improvements such as permittivity and space charge accumulation [2]. This research work investigates the effect of Nano fillers content on the PD resistance and Breakdown strength of the polypropylene films with 0%, 2% and 6% organoclay Nano fillers when the samples are subjected to Surface Discharges. The degree of erosion is quantified through microscopic and surface profilometer measurements that will help to figure out the resistance of the sample to surface discharges.
electrical insulation conference | 2011
Bhargavi Sarang; Prathap Basappa; V.K. Lakdawala; Gayathri Shivaraj
The effect of droplets on the surface of the overhead insulators (porcelain and silicone rubber) and their contributions to electric field distribution and hence possibility of failure is investigated. Initially the variation of electric field distribution around a typical water droplet in the sheath and shed regions as a function of contact angle is investigated. The effect on field distribution in presence of multiple droplets is explored by varying the number, the relative positioning and contact angle.
electrical insulation conference | 2009
Anusha Jambula; V. Nimbole; V.K. Lakdawala; Prathap Basappa
A typical set of partial discharges (PD) occurring in insulation systems can be characterized by a three dimensional plot of their phase ‘ϕ’ on the power line cycle, apparent charge magnitude ‘q’ and the number of pulses ‘n’. A digital acquisition system is being developed which can measure ‘ϕ’ and ‘q’ values of ‘n’ PDs occurring on a given power line voltage and then plot n(ϕ, q). The system is developed using the data acquisition card NI- 5112, which is a 2-channel high speed digitizer (100 MS/s) with the acquisition and analyses programs written in LabVIEW 8.2. The system is being tested using artificially generated PD pulses which have variable ‘ϕ’ and ‘q’ magnitudes and their performance benchmarked by comparing the resulting plots with the plots obtained by processing the same data on existing PD analyses system called TECHIMP- PD check.