Time-Domain Protection and Fault Location of Wye-Connected Shunt Capacitor Banks Using Superimposed Current and Differential Voltage

This paper presents protection and fault location of wye-connected shunt capacitor banks used in medium or high voltage applications. The proposed method is sensitive to single element failure obtained by using voltage adaptive instantaneous superimposed current in each phase. The change in equivalent reactance computed using time-domain signals is used to find the number of failed capacitor element and types of fault. The location of the faulted capacitor is identified using sign of the voltage difference of the lower and upper halves of the shunt capacitor bank. The performance of the proposed method is tested for various cases including identical faults, simultaneous faults, system voltage unbalance in both single and double wye-connected shunt capacitor banks. The method is also validated using field data collected from a 400 kV SCB for an internal fault. The proposed technique is compared with available methods and found accurate

Exploring Cherishing: A Qualitative Approach

The word cherishing is frequently used in our daily jargons. It is also very often mentioned in empirical literature on cherished possessions. However, despite the relevance of the term in the empirical literature on cherished possessions, very little is known about the way it operates in people’s lives. The only link with cherishing happens to be the studies conducted in individualistic cultures on cherished possessions. Besides, there is hardly any consensus on how cherishing operates in collectivistic culture such as India owing to the scarce literature available on the topic. Hence, the present study addresses the gap in the literature with the objective to explore the concept of cherishing. The present study examines cherishing through qualitative investigation by using semi-structured interviews in India. Forty-eight participants were interviewed for the study. Analysis of the data based on grounded theory techniques revealed three major themes: (i) the attributes of cherishing, (ii) functions of cherishing and (iii) the objects of cherishing. The attributes of cherishing convey a sense of protectiveness, a tendency to care, affective orientation and reminiscence. The functions reveal the benefits experienced from cherishing. The objects of cherishing convey the targets towards which one experiences cherishing. Recommendations for further study, along with theoretical and practical implications of the study findings, are also discussed

Workplace spirituality in indian organisations: construction of reliable and valid measurement scale

The purpose of the paper was to develop and validate a comprehensive tool for measuring workplace spirituality. On the basis of literature, feedback from academic and industry professionals, a heuristic framework along with a scale on workplace spirituality was proposed and a questionnaire was developed. The instrument obtained empirical views from experts on its dimensions and statements. Content validity ratio (CVR) of the instrument was carried out and the retained items were taken for field survey. Three hundred and sixty one executive respondents employed in manufacturing and service organisations in Indian subcontinent responded to the 44 items scale assessing different facets of spirituality at workplace. This helped to validate the factors of workplace spirituality and optimize the contents of the proposed instrument with the help of structural equation modelling. Exploratory factor analysis revealed four distinct factors that constitute the new instrument of workplace spirituality: spiritual orientation, compassion, meaningful work, and alignment of values. Reliability analysis reported high level of internal consistency of the total scale (α = .78) and the five subscales (α's ranging from .75 to .87). Finally, 30 items were retained with four important factors of Workplace Spirituality Scale

A Cosine Similarity Based Centralized Protection Scheme for DC Microgrids

Unlike the phasor measurement based protection in AC systems, the protection of DC systems deals with complex fault transients which mandates the isolation of the faulted segment within few milliseconds as continued fault current leads to overheating issue in power electronic converters. To this end,several works have been suggested based on unit and nonunit protections for DC microgrids. Threshold selection and protection coordination are the challenges associated with nonunit protection. Similarly, communication delay and link failure limit the application of unit protection. To address these issues, this paper presents a robust centralized protection scheme for DC microgrids, which is resilient to communication delay and link failure. It uses current of each line segment to compute the similarity of current change at both ends of the line segment to derive the protection decision. To overcome the communication failure from one end of the line segment or even from multiple segments, the proposed method uses data from adjacent segments to derive the protection decision correctly. Using PSCAD/EMTDC environment, the performance of the proposed method is evaluated for various cases and compared with available techniques. Finally, the accuracy of the protection algorithm is validated under experimental conditions

Finite Element Based Vibration Analysis of a Nonprismatic Timoshenko Beam with Transverse Open Crack

AbstractThe present day structures and machineries are designed based on optimizing of multi-objectives such as maximum strength, maximum life, minimum weight and minimum cost. Due to this they are flexible and allow having a very high level of stresses. This leads to development of cracks in their elements. Many engineering structures may have structural defects such as cracks due to long-term service. So it is very much essential to know the property of structures and its response in various cases. The present article deals with finite element based vibration analysis of a nonprismatic cracked beam. The beam is modeled using the Timoshenko beam theory. The governing equation of motion is derived by the Hamilton's principle. In order to solve the governing equation two noded beam element with two degrees of freedom (DOF) per node is considered. In this work the effect of structural damping is also incorporated in the finite element model. The dynamic analysis is carried out by using state space model in time domain

Structural validity of r-spq-2f: A confirmatory factor analysis

The aim of this study is to validate the internal structure of the Revised-Study ProcessQuestionnaire-2 Factors (Biggs, Kember & Leung, 2001), through a heterogeneous sampleof 269 university and non-university participants. The structural equation methodology isused to test several measurement models: one-dimensional, four factors and hierarchicalstructure, and two factors (orthogonal and oblique).Theodels based on four factors did notshow a satisfactory adjustment, and one had convergence problems caused by a very highinterfactorial correlation. The two-factor model (deep and shallow) with correlated errorshad a satisfactory adjustment. The internal consistency was satisfactory. The usefulness ofthe instrument and its theoretical reformulation is discussed.El motivo del presente estudio es validar la estructura interna del Cuestionario Revisado de Procesos de Estudio, Dos factores (Revised-Study Process Questionnaire-2 Factors; Biggs, Kember & Leung, 2001), en una muestra heterogénea de 269 participantes universitarios y no universitarios. Se aplicó la metodología de ecuaciones estructurales para probar varios modelos de medición: unidimensional, cuatro factores relacionados y con estructura jerárquica, y dos factores (ortogonales y oblicuos). Se halló que los modelos basados en cuatro factores no mostraron un ajuste satisfactorio, y uno tuvo problemas de convergencia ocasionados por la muy alta correlación interfactorial. El modelo de dos factores (profundo y superficial), con errores correlacionados, tuvo satisfactorio ajuste. La consistencia interna también fue satisfactoria. Se discute la utilidad del instrumento y su reformulación teórica