Senthilkumaran Mahadevan, Siddharth Raju and Ranganath Muthu
The high-frequency common-mode voltage introduced by power converters, using conventional modulation techniques, results in common-mode current that has the potential to cause…
Abstract
Purpose
The high-frequency common-mode voltage introduced by power converters, using conventional modulation techniques, results in common-mode current that has the potential to cause physical damage to the shaft and bearings of electric drives as well as unwanted tripping of ground fault relays in motor drives and electrical networks. The paper aims to provide a complete elimination of common mode voltage using a matrix converter (MC) with a new modulation strategy that reduces the size of the power converter system considerably. Further, a new MC topology is proposed to eliminate the common mode voltage with improved voltage transfer ratio (VTR).
Design/methodology/approach
The direct MC topology is selected, as it is the only converter topology that has the potential to eliminate common mode voltage in direct AC to AC systems. Using the rotating space vector technique, common mode voltage is eliminated but this reduces the VTR of the converter. To improve the VTR, a modified MC topology with a modified rotating space vector strategy is proposed. In addition, for improving the power factor at the input, the input current control strategy is developed.
Findings
The use of rotating space vector technique eliminates the common mode voltage even under all input abnormalities like unbalance and harmonics. By applying positive and negative rotating space vectors, input power factor control can be achieved. However, the control range is limited from unity power factor to the output power factor. It is observed that in the current controlled technique the modulation index reduces further. It is also found that there is a reduction in switching stresses of individual switches in proposed topology compared to direct MC topology.
Originality/value
In this paper, a modified rotating space vector technique is applied to the proposed converter topology for elimination of common mode voltage with an increased VTR. The topology can be used for common mode voltage elimination in existing electric drives without the need for modifying the drive system.
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The case illustrates an entrepreneurial voyage and venture creation and through it helps in identifying the reasons and causes for that venture's failure. It also enables…
Abstract
The case illustrates an entrepreneurial voyage and venture creation and through it helps in identifying the reasons and causes for that venture's failure. It also enables discussion on the importance of planning a venture, more importantly; financing, managing, growing, and ending a venture and on how to avoid the pitfalls that befall such enterprises. This case can be used in Entrepreneurship courses as well as MBA, PGP and Executive Education programmes on Entrepreneurship.
Sharmili Das, Rohit Siddharth Dhabarde and V. R. K. Raju
The purpose of this study is to develop a novel rectangular linear induction motor as an electromagnetic stirrer (EMS) using analytical followed by a numerical approach. The…
Abstract
Purpose
The purpose of this study is to develop a novel rectangular linear induction motor as an electromagnetic stirrer (EMS) using analytical followed by a numerical approach. The rectangular linear electromagnetic stirrer (RLEMS) is mainly developed for rectangular slab and billet as the end product.
Design/methodology/approach
A two-dimensional analytical approach for evaluating flux density distribution within the mold is established for RLEMS structure. Subsequently, the average stirring force within the mold is estimated from those field variables. The paper presents an analytical and numerical model for calculating the stirring force and counters the end and edge effects of linear-type EMS. Magnetic field and force profile within the mold due to polyphase rectangular stator distribution has been done with the help of Maxwell’s equation with appropriate boundary conditions by using Fourier transform and inverse Fourier transform. Subsequently, a numerical study has been carried out using a coupled thermal and electromagnetic model.
Findings
The present study investigates the physical phenomena during the solidification process because of an induced electromagnetic field and is able to extract all the electromagnetic field variables under different operating conditions, and, subsequently, provides an insight into the actual happening within the mold.
Originality/value
It provides the analytical method for solving the stirring force of the proposed new RLEMS structure by addressing the smooth and efficient variation of field and velocity profile near the corner of the mold and improves the quality of end product.
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Siddharth Misra and Rajeev Kumar Panda
The purpose of this paper is to investigate the activities of environmental consciousness from socio-psychographic perspectives and hence evaluates its effect on brand equity…
Abstract
Purpose
The purpose of this paper is to investigate the activities of environmental consciousness from socio-psychographic perspectives and hence evaluates its effect on brand equity through intervening elements of environmental attributes (EAt). It further attempts to research the effect of the environmental performance, environmental communication and environmental positioning in enhancing brand equity. Indian refrigeration industry, particularly the air conditioners and refrigerator brands are chosen to convey and receive the research inputs as their impact on environment is easily interpretable.
Design/methodology/approach
A hypothesized model comprising the environment consciousness and association dimensions with brand equity is framed. In total, 74 expert respondents from four state capital cities of India participated in the survey and the model has been tested in the scope of analytical hierarchy process (AHP).
Findings
The result shows that the EAt and activities can be prioritized and subsequently efficient resource allocation can be done. It also gives theoretical arguments to legitimize the environmental practices.
Practical implications
On the other hand, clients have numerous options, and a competitive advantage may not be maintained. Regardless of the fact that clients are environmentally conscious of a given refrigeration brand at the present time that they are utilizing, they may observe that they are much more charmed with a competitors’ enhanced environmental dimensions. All methods that take a try at an enhanced brand equity must be continually determined by environmental consciousness. The above can be accomplished if the evaluations of competitors by the clients are known. The AHP-ECBE technique depicted in this study accordingly helps refrigeration organization to devise and keep up a pertinent, focused plan for persistent improvements in environmental dimensions. It offers a “greater image” in brand equity administration.
Originality/value
If legitimately done in a generalized way, environmental activities like eco-literacy, interpersonal influence and value orientation can impact EAt and contribute in building brand equity.
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Syed Modassir Hussain, Rohit Sharma, Manoj Kumar Mishra and Jitendra Kumar Singh
Nanosized honeycomb-configured materials are used in modern technology, thermal science and chemical engineering due to their high ultra thermic relevance. This study aims to…
Abstract
Purpose
Nanosized honeycomb-configured materials are used in modern technology, thermal science and chemical engineering due to their high ultra thermic relevance. This study aims to scrutinize the heat transmission features of magnetohydrodynamic (MHD) honeycomb-structured graphene nanofluid flow within two squeezed parallel plates under Joule dissipation and solar thermal radiation impacts.
Design/methodology/approach
Mass, energy and momentum preservation laws are assumed to find the mathematical model. A set of unified ordinary differential equations with nonlinear behavior is used to express the correlated partial differential equations of the established models, adopting a reasonable similarity adjustment. An approximate convergent numerical solution to these equations is evaluated by the shooting scheme with the Runge–Kutta–Fehlberg (RKF45) technique.
Findings
The impression of pertinent evolving parameters on the temperature, fluid velocity, entropy generation, skin friction coefficients and the heat transference rate is explored. Further, the significance of the irreversibility nature of heat transfer due to evolving flow parameters are evaluated. It is noted that the heat transference rate performance is improved due to the imposition of the allied magnetic field, Joule dissipation, heat absorption, squeezing and thermal buoyancy parameters. The entropy generation upsurges due to rising magnetic field strength while its intensification is declined by enhancing the porosity parameter.
Originality/value
The uniqueness of this research work is the numerical evaluation of MHD honeycomb-structured graphene nanofluid flow within two squeezed parallel plates under Joule dissipation and solar thermal radiation impacts. Furthermore, regression models are devised to forecast the correlation between the rate of thermal heat transmission and persistent flow parameters.