Papers by ABDUL KHADAR SHAIK
Comparative Analysis of CHB and CSD Multilevel Inverter
Springer Proceedings in Energy, 2021
2020 International Conference on Smart Technologies in Computing, Electrical and Electronics (ICSTCEE), 2020
The chemical abundances of exoplanet atmospheres may provide valuable information about the bulk ... more The chemical abundances of exoplanet atmospheres may provide valuable information about the bulk compositions, formation pathways, and evolutionary histories of planets. Exoplanets with large, relatively cloud-free atmospheres, and which orbit bright stars provide the best opportunities for accurate abundance measurements. For this reason, we measured the transmission spectrum of the bright (V∼10.2), large (1.37 R 𝐽 ), sub-Saturn mass (0.19 M 𝐽 ) exoplanet WASP-127b across the near-UV to near-infrared wavelength range (0.3-5 𝜇m), using the Hubble and Spitzer Space Telescopes. Our results show a feature-rich transmission spectrum, with absorption from Na, H 2 O, and CO 2 , and wavelength-dependent scattering from small-particle condensates. We ran two types of atmospheric retrieval models: one enforcing chemical equilibrium, and the other which fit the abundances freely. Our retrieved abundances at chemical equilibrium for Na, O and C are all super-solar, with abundances relative to solar values of 9 +15 -6 , 16 +7 -5 , and 26 +12 -9 respectively. Despite giving conflicting C/O ratios, both retrievals gave super-solar CO 2 volume mixing ratios, which adds to the likelihood that WASP-127b's bulk metallicity is super-solar, since CO 2 abundance is highly sensitive to atmospheric metallicity. We detect water at a significance of 13.7 𝜎. Our detection of Na is in agreement with previous ground-based detections, though we find a much lower abundance, and we also do not find evidence for Li or K despite increased sensitivity. In the future, spectroscopy with JWST will be able to constrain WASP-127b's C/O ratio, and may reveal the formation history of this metal-enriched, highly observable exoplanet.
Analysis of Photo Voltaic Based Active Boost Inverter for Asynchronous Motor Drives
2020 IEEE-HYDCON, 2020
This paper deals with the modification of switch position and minimize stress on Active buck boos... more This paper deals with the modification of switch position and minimize stress on Active buck boost inverter (ABI). The performance of conventional ABI is analysed with voltage stress and Total harmonic distortions (THD) for RL loads. Similarly the estimation for the performance of the modified ABI is analysed with same load parameters and it is compared with conventional ABI, which results in degrade of voltage stress. The variation in the irradiance of PV is analysed with modified ABI to obtain the voltage stress. The optimization of coupled inductor L1 and L2 is utilized in obtaining the variation with voltage stress. The effects of voltage stress results in the deviation of temperature distribution for MOSFET. The temperature distribution in MOSFET is observed using Finite Element Analysis (ANSYS). The Asynchronous motor is connected to the proposed ABI to determine its suitable applications.
Effect of Active Time Adjustment in Space Vector Pulse Width Modulation Strategy
2021 International Conference on Sustainable Energy and Future Electric Transportation (SEFET), 2021
This paper deals with space vector pulse width modulation (SVPWM) which is one of the most popula... more This paper deals with space vector pulse width modulation (SVPWM) which is one of the most popular techniques to control the inverter power switches. SVPWM is the implementation of space vector as modulating wave along with a carrier wave. In direct SVPWM the switching time is directly calculated from active and zero time equations and in modified SVPWM we increase the active times from above equations by simultaneously decreasing the zero state times. Thus direct SVPWM and modified SVPWM techniques are carried using MATLAB/ simulink for a 3 phase Voltage source inverter (VSI) and result is tabulated.
Modelling of Renewable Energy Source Fed Active Buck-Boost Inverter for Grid Interface Systems
UPB Scientific Bulletin, Series C: Electrical Engineering and Computer Science, 2020
In Renewable energy sources the voltage range is governed by environmental conditions, sunlight. ... more In Renewable energy sources the voltage range is governed by environmental conditions, sunlight. The energy systems must be capable enough for large input voltage and have operation like boosting voltage and vice versa. This article illustrates a single-phase inverter topology as buck-boost inverter which suits with extensive range of variations in the input. The various operating modes, voltage gain, efficiency of inverter is to be properly investigated, with the selection for the turn’s ratio with combined inductors, this inverter can be operated under both buck boost operations. In timely operation of duty ratio with AC/AC unit, coupled inductors voltage gain is achieved. Various control strategies of inverter are to be analyzed and compared. The power quality issues when renewable energy sources are integrated with grid through buck boost inverter are discussed. The mitigation of various power quality problems is to be designed and tested.
With oil supplies decreasing and prices increasing, the energy sources are being debated world-wi... more With oil supplies decreasing and prices increasing, the energy sources are being debated world-wide. Now a days with the growing population and energy demand we should take a renewable option of energy source and also we should keep in mind that energy should not cause pollution and other natural hazards. In this case the solar energy is the best option for us. India is a highly populated country so we should take the advantage of such an energy which requires a very less space to produce energy efficiently. In this case solar tree could be the best one for us. This paper introduces a new solar technology that emulates how trees convert sunlight into energy. With the tree structured arrangement we introduce a new idea to design a solar tree using nanowire solar cell. Nanoparticles exhibit a number of special properties relative to bulk material. A single Nanowire concentrates the sunlight upto 15 times of the normal sunlight intensity. Surprising results have the potential for developing a new kind of highly efficient solar cell. Nanowires possess some distinctive physical light absorption properties. Because of these properties, the limit of how much energy from the sun's rays we can use is higher than previously thought. For many years it has been a high mark for solar cells efficiency among researchers, but now there is possibility that it may be raised higher. Hence it is a revolutionary urban lighting concept that not just trees but other objects can also be decorated. These technologies eventually lead to the point of view and also more efficient. So this will be a very good option and should be implemented can be applied in street lightening system, industrial power supply etc. It is much better than the traditional solar PV system in area development of high efficiency solar cells .
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Papers by ABDUL KHADAR SHAIK