Journal Articles
Permanent URI for this collectionhttps://idr.nitk.ac.in/handle/123456789/19884
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Item Recent advances in 2D MXenes for enhanced cation intercalation in energy harvesting Applications: A review(Elsevier B.V., 2020) Hemanth, N.R.; Balasubramanian, B.An advanced energy harvesting device that can be powerful with rapid storage mechanism, effective conservation, intact and secure recycling presently fascinate and are increasingly developed with the proper synthesis strategy and combination of nanomaterials with complementary properties. In 2011 extensive research has led to the wide emanating family of two-dimensional (2D) multi-layered transition metal carbides, carbonitrides and nitrides in conjunction with surface terminations namely fluorine, hydroxyl or oxygen which add hydrophilicity to their surfaces, these are collectively known as MXenes, they are derived from a selective etching of atomically thin sheets of ‘A’ element from MAX phases in the acidic solutions which contain aqueous fluoride. The gifted chemistry and unique morphology of MXenes allow us to use them for distinct applications which includes energy storage, electromagnetic interference shielding, anti-bacterial activity, nanofiltration of water, reinforcements, nuclear waste management, and catalysis. The excellent properties inclusive of high lithium (Li) storage capacity, rapid diffusion of Li, and low operating voltage make the MXenes a promising electrode, the macroporous Ti3C2Tx sheets display gravimetric nearly 210 Fg−1 at scan rates of 10 Vs−1 which exceeds finest carbon supercapacitor and MXene hydrogels can have volumetric capacitances nearly 1500 F·cm−3. In this context, this review provides state of the art for the synthesis of MXenes, it's structure, intercalation, delamination, properties and thorough understanding between nanostructure and electrochemical performance which will encourage further study of 2D MXenes in energy harvesting applications. © 2019 Elsevier B.V.Item Multifunctional conjugated 1,6-heptadiynes and its derivatives stimulated molecular electronics: Future moletronics(Elsevier Ltd, 2020) Magisetty, R.; Hemanth, N.R.; Kumar, P.; Shukla, A.; Shunmugam, R.; Balasubramanian, B.Over the past decade conducting polymers have been studied for electronic applications, among them, molecular electronics: the study and investigation of molecular building blocks is a next-generation demanded area of research. Hence, the moletronic equivalent multi-functional advantages of cyclopolymerized 1,6-heptadiyne (HD) systems explored in this review. Further, this report elucidates physical properties via conditional cyclopolymerization methodologies, it describes the chemistry of tethering molecular-chains facilitated intrinsic-conductivity. HD and its derivatives induce superior conductivity characteristics via doping elements, wherein, significant electronic conductivity mechanism is attributable to the solitons and anti-solitons, which was described in this context. HD and their derivatives molecular mechanism, its compatibility are expounded for moletronic application, which is new insight of the article. Moreover, required inherent characteristics, for e.g., thermal-stability, chemical-resistance, mechanical properties, magnetic, and electronic properties have been discussed. Furthermore, failures, physical limitations, and its realizable similarity solutions for moletronics have described. Though electronic or moletronic components having failures and other physical limitations, HDs offers excellent conductivity with wide functional and physical properties that could lead to potential candidates to deliver efficient and low-cost moletronic devices. © 2019 Elsevier LtdItem EGA-FMC: Enhanced genetic algorithm-based fuzzy k-modes clustering for categorical data(Inderscience Enterprises Ltd., 2018) Narasimhan, M.; Balasubramanian, B.; Kumar, S.D.; Patil, N.Categorical data clustering is the unsupervised technique of grouping similar objects which have categorical attributes. We propose a genetic algorithm-based fuzzy k-modes categorical data clustering algorithm using multi-objective rank-based selection with enhanced elitism operation. Compactness of the clusters and inter-cluster separation were chosen as objectives to be optimised. During elitism, in every iteration, the best parent chromosomes were identified. The entire population was passed through the selection, crossover and mutation steps. The worst children were then replaced by the best parents. Our method was evaluated on three real-world datasets and resulted in clusters of better quality as compared to current methods with a significant reduction in computation time. Additionally, statistical significance tests were conducted to show the superiority of our approach over other clustering solutions. © © 2018 Inderscience Enterprises Ltd.Item Global Peak Tracking of Photovoltaic Array under Mismatching Conditions Using Current Control(Institute of Electrical and Electronics Engineers Inc., 2019) Ramana, V.V.; Mudlapur, M.; Damodaran, R.; Balasubramanian, B.; Mishra, S.Characteristics of photovoltaic arrays exhibit multiple peaks under mismatching conditions. In order to harness maximum energy, it is imperative to track the global maximum power point. A novel global peak tracking algorithm is proposed using current control in this paper. The proposed method operates in the backward phase and forward phase to track the global peak. The objective of the proposed algorithm is to track the global maximum accurately with minimum tracking time. The enhanced performance of the proposed algorithm is verified using simulations by comparing it with an existing method. Experimental validation is done using a solar array simulator, boost converter, resistive load, and dSPACE controller. Experimental results are in close agreement with simulation. The proposed algorithm is intended to track the global peak of a PV string that contains a group of modules. © 1986-2012 IEEE.Item Effect of Partial Shading on PV Fed Induction Motor Water Pumping Systems(Institute of Electrical and Electronics Engineers Inc., 2019) Mudlapur, M.; Ramana, V.V.; Damodaran, R.; Balasubramanian, B.; Mishra, S.Partial shading is one of the certain conditions in photovoltaic (PV) power plants. Often the panels get partially shaded due to soiling, clouds, and trees. The effect of shading is of high concern and importance especially in applications such as water pumps due to agricultural environments in which they are employed in. However, the research focus on PV fed pumps till date has been restricted to only uniform shading conditions. Unlike uniform shading conditions during maximum power tracking, where the panel voltage remains almost constant for an entire range of irradiance, partial shading offer conditions such as highly variable panel voltage and transitions of intermediate DC-DC power converter from continuous conduction mode to discontinuous conduction mode. These effects severely affect the performance of the power converter and, therefore, the power output of the pump. This paper presents a study on the effects caused by partial shading conditions on pumps through simulations and verified by experimentations. The simulation and experimental results are found to be in good agreement with each other. This research thus helps in understanding the detrimental effects caused by partial shading conditions and thus serves as a reference tool for practitioners who wish to study PV fed pumps. © 1986-2012 IEEE.Item An Iterative Analytical Solution for Calculating Maximum Power Point in Photovoltaic Systems under Partial Shading Conditions(Institute of Electrical and Electronics Engineers Inc., 2019) Mudlapur, M.; Ramana, V.V.; Damodaran, R.; Balasubramanian, B.Detection of maximum power point (MPP) is one of the most sought-after topics in the field of photovoltaic systems. There are many approaches to detecting MPP, amongst these are analytical methods. Analytical methods use mathematical functions to solve the given problem and therefore are one of the dominant strategies. However, their applications to detect MPP have been limited to study only uniform shading conditions. The use of analytical methods to detect MPP for more challenging cases like partial shading conditions is yet to be investigated. In this brief, an analytical solution to identify MPP under partial shading conditions is proposed. Equations describing photovoltaic panels and MPP conditions are derived by applying fundamental circuit laws. The derived equations are non-linear and can be solved using numerical techniques available in most of the simulation packages. The proposed model can theoretically detect the MPP amongst 'N' peaks. The results from the simulation are verified by conducting experimentation with standard algorithms available in the literature. The results from simulation and experimentation are found to agree with each other. © 2004-2012 IEEE.Item Small Signal Model for PV Fed Boost Converter in Continuous and Discontinuous Conduction Modes(Institute of Electrical and Electronics Engineers Inc., 2019) Mudlapur, M.; Ramana, V.V.; Damodaran, R.; Balasubramanian, B.Small signal models are of high importance in power electronic systems which exhibit highly non-linear properties. They provide access to stability and help in tuning controllers. Small signal models for many power electronic converters are seen in the literature. However, specific applications like photovoltaic systems demand the addition of a capacitor at the terminals of photovoltaic (PV) panel. Since this capacitor is connected between the PV panel terminals and the input of power converter, it is termed as input capacitor. The effect of the addition of input capacitor on system stability has not been addressed yet. In this brief, we derive the small signal models for PV fed boost converter operating in both continuous conduction mode (CCM) and discontinuous conduction modes (DCM) of operation. The load is assumed as purely resistive; however, the analysis holds good for any practical loads. It is observed that in both CCM and DCM the stability of the maximum power point tracking (MPPT) system is independent of the input capacitance. It is also shown that the MPPT system is open loop stable for all operating conditions. The studied models are further validated with the experimental setup. © 2004-2012 IEEE.Item A Novel AC Current Sensorless Hysteresis Control for Grid-Tie Inverters(Institute of Electrical and Electronics Engineers Inc., 2020) Damodaran, R.; Mudlapur, A.; Ramana, V.V.; Balasubramanian, B.; Mishra, S.Amongst the modulation techniques used for grid-Tie inverters (GTIs), hysteresis current control (HCC) facilitates simple, stable and rugged control with improved dynamic response. However the variable switching frequency of HCC demands high precision AC current sensors (CS) which introduce noise in the power circuit in addition to measurement noise and delay. Therefore, this brief presents a hysteresis current control without AC current sensor based on switching instant computation for a two-level GTI. The proposed control strategy uses the DC link and instantaneous grid voltages to calculate the switching instants. The conventional methods of calculating switching instant of HCC can result in tracking errors. Hence the computations are modified in the proposed algorithm considering the effects of non-linearity in error current and dynamic variations due to supply and load changes. A single-phase GTI is simulated with the proposed control and the results are verified experimentally. The proposed method is observed to considerably reduce the computational time, DC shift and total harmonic distortion compared to the commonly used sensorless current control. © 2004-2012 IEEE.Item Poly(1,6-heptadiyne)/NiFe2O4 composite as capacitor for miniaturized electronics(Bellwether Publishing, Ltd., 2020) Magisetty, R.; N R, H.; Shukla, A.; Shunmugam, R.; Balasubramanian, B.Impedance spectroscopy-based electrical measurements were conducted on different molecular weight (MW) Poly(1,6-heptadiyne)s (PHDs) embedded PHD/NiFe2O4 nanocomposites. Nanocomposites conductivity result demonstrated the conductivities of around (Formula presented.) (nanocomposite Root mean square (RMS) current is 12–15 times greater than DC current of PHDs at 27° C). Additionally, dielectric loss and capacitance characteristics suggested the nanocomposite (4500 MW PHD) device quality factor is 35.7 at 1 kHz, which is ~13.89 times superior than that of NiFe2O4 alone sample, also ‘Q’ value for highest MW PHD nanocomposite is 50% enhanced than NiFe2O4. Moreover, the capacitance result suggested the 12400 MW PHD nanocomposite nearly frequency-independent capacitance (15–20pF) over a frequency range of 500 Hz–500 kHz. © 2020 Taylor & Francis.Item Modified Current Control for Tracking Global Peak Under Fast Changing Partial Shading Conditions(Institute of Electrical and Electronics Engineers Inc., 2022) P, P.; Vignesh Kumar, V.; Balasubramanian, B.; Ramana, V.The power - voltage (P-V) characteristics of photovoltaic (PV) systems exhibit multiple power peaks under partially shaded conditions. Several global maximum power point tracking (GMPPT) algorithms in the literature recognize the irradiance change, only after the convergence of operating point to global peak, or use additional hardware to call GMPPT subroutine at definite time intervals to detect any insolation change, and thus track the global peak. However, during fast changing partial shading conditions, these methods are less effective, as they do not detect any irradiance change during the tracking phase of any shading pattern. This paper proposes a novel modified current control approach that uses current as a parameter to detect the insolation change during the tracking phase and track the global peak under fast changing partial shading conditions without any additional hardware. The proposed technique improves the tracking efficiency by as much as 39%, thus proving to be effective under fast-changing partial shading conditions. The superior tracking performance of the proposed algorithm over the existing techniques in terms of its tracking efficiency, dynamic tracking capability, tracking speed, and convergence to the global peak is demonstrated with extensive simulations using MATLAB/Simulink and experimental results. © 1986-2012 IEEE.