Electrical Engineering

<p>Shiv Nadar University is a comprehensive, multidisciplinary, research-focused, and student-centric University offering a full range of academic programs at the undergraduate, postgraduate and doctoral level. With state-of-the-art infrastructure, the University comprises of academic wings, sophisticated labs, international standard sports facilities, amphitheaters, auditorium, conference rooms and smart classrooms. The University&rsquo;s goal is to become internationally recognized for the quality of its research and creative endeavors and their applicability to improving quality of life, generating new insights and expanding the boundaries of human knowledge creativity. Committed to excellence in teaching, research and service, the University aims to serve the higher education needs of India and the world beyond.</p>

Shiv Nadar University

We report the effects of annealing in conjunction with CdCl2 treatment on the photovoltaic properties of CdTe/Zn0.1Cd0.9S thin film solar cells. CdTe layer is subjected to dry CdCl2 treatment by thermal evaporation method and subsequently, heat treated in air using a tube furnace from 400 to 500°C. AFM and XRD results show improved grain size and crystallographic properties of the CdTe film with dry CdCl2 treatment. This recrystallization and grain growth of the CdTe layer upon CdCl2 treatment translates into improved photo-conversion efficiencies of CdTe/Zn0.1Cd0.9S cell. The results of dry CdCl2 treatment were compared with conventional wet CdCl2 treatment. Photo-conversion efficiency of 5.2\% is achieved for dry CdCl2-treated cells in comparison with 2.4\% of wet-treated cell at heat treatment temperature of 425°C. © Indian Academy of Sciences.

(SoE) School of Engineering

World University root node

Fulltext

Bulletin of Materials Science

Effect of annealing temperature and CdCl2 treatment on the photo-conversion efficiency of CdTe/Zn0.1Cd0.9S thin film solar cells

This paper proposes a method for gesture classification based on Graph Fourier transform (GFT) coefficients. GFT coefficients are the projection of image pixel block onto the eigenvectors of a Laplacian matrix. This Laplacian matrix is generated from undirected graph, representing a spatial connectedness between each pixel within an image block. This work proposes a method for generating an undirected graph by using edge information of the image. Edge information of the image is obtained by average sum of absolute difference between the current pixel and its neighboring pixels by using an appropriate threshold. The resulting GFT based feature vector is formed by concatenating GFT coefficients of each block. The resultant feature vector is applied to linear Support Vector Machine (SVM) classifier to predict the gesture class. For NTU and Massey hand gesture datasets, threshold value 30 gives maximum prediction accuracy. We compare the results of the proposed GFT based descriptor approach with Karhunen-Loeve transform (K-LT) and Discrete Cosine transform (DCT) based descriptors on three different gesture datasets: NTU, Cambridge and Massey. Simulation results show that the proposed GFT based descriptor gives a comparable results with Karhunen-Loeve transform (K-LT) and Discrete Cosine transform (DCT) based descriptors for gesture classification. © 2017 IEEE.

Mathematics

(SoNS) School of Natural Sciences

2017 4th International Conference on Image Information Processing, ICIIP 2017

Graph fourier transform based descriptor for gesture classification

This paper proposes the precoder for Multi User-MassiveMIMO (MU-MaMI) frequency selective broadcast channels with few User Terminals(UTs) having single antenna each. The frequency selective effect of the MaMI channel will be manifested as ISI and IUI. In order to mitigate these interferences and to eliminate the group level decoding of UTs, a precoder is proposed utilizing the block time Channel Impulse Responses (CIRs). This proposed precoder is designed based on the following approaches, Matched Filter(MF), Zero Forcing (ZF), Minimum Mean Square Error (MMSE) and Regularized Channel Inversion (RCI). The performance of these precoders is evaluated using single symbol time (one time symbol) and block time symbols (N time symbols) of each UT. The optimal length N block time symbols and minimum number of Base Station (BS) antennas required for a given N block time and multipath L is evaluated with respect to the Signal-to-Interference Noise Ratio (SINR) asymptotic limits. © 2017 IEEE.

Proceedings of the 2017 International Conference on Wireless Communications, Signal Processing and Networking, WiSPNET 2017

Space-time block based linear precoders for multi user-MassiveMIMO frequency selective broadcast channels

It is mandatory to keep the total harmonic distortion in the output of most inverters below the limits prescribed by different international standards. The harmonic distortions caused due to nonlinear loads may not get corrected by typical magnitude controller, like PID controller. Repetitive controller is more effective in such situations. Often, repetitive controller is used as add-on block to the conventional magnitude controller. Design of repetitive controller can be easily implemented on digital platform. Rapid change in phase and magnitude of inverter-filter's transfer function near corner frequency causes instability problems in repetitive controller. Various techniques have been proposed by researchers to overcome this problem. Most of the reported techniques rely on digital compensation. However, it is hard to find a digital compensator, which simultaneously meets the phase and gain requirements at moderate computational effort. Here, a new output voltage feedback scheme has been proposed, which simplifies the requirement of digital compensation. The proposed scheme requires an extra hardware but at negligible added cost. In spite of this extra hardware, the proposed circuit turns out to be more energy efficient in comparison to few popular schemes, reported in literature, where some resistance is introduced in the inverter's filter for better stability of controller. In addition to the proposed modification the paper presents a simplified explanation of the various factors affecting stability of repetitive controller. The paper also discusses a novel experimental method for verifying the efficacy of repetitive controller in suppressing distortion of any particular harmonic order. © 1986-2012 IEEE.

IEEE Transactions on Power Electronics

A Modified Feedback Scheme Suitable for Repetitive Control of Inverter with Nonlinear Load

In this work, we have added p-type and n-type Si nanoparticles (NPs) obtained from cryomilling, in poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) organic photovoltaic cell at different weight ratios and their effect on organic-inorganic hybrid solar cell device parameters has been evaluated. It is observed that the addition of p-type nanoparticles tailors the energy band alignment at the P3HT/NP interface which provides efficient charge carrier transport enhancing the photo-conversion efficiency by more than 21%. Enhancement is reflected by an improvement in short-circuit current by ∼35% with respect to reference P3HT:PC61BM device without Si NPs. However, for n-type NPs where the optimum cascading band alignment does not occur, only 10% improvement in photo-conversion efficiency is observed. This work provides insight into how the performance of organic solar cells can be tailored by size factor as well as byenergy level tuning of the added nanoparticles. © 2018

Solar Energy

Doped silicon nanoparticles for enhanced charge transportation in organic-inorganic hybrid solar cells

This paper presents a new approach to physical relocation of photovoltaic (PV) modules in Totally Cross Tied (TCT) configuration of an array without altering the electrical connection. This proposed arrangement is a one time arrangement at the time of installation and this arrangement ensures for the enhancement of power generation of the PV array under partial shading conditions. In this arrangement, the shading effects are distributed over the entire array and hence reduce the multiple peaks in the power-voltage characteristics. The power generated by the proposed arrangement of a PV array is compared with the TCT configuration under different shading patterns. Also, the mismatch loss in the proposed configuration is compared with existing configurations under different shading patterns. © 2018 IEEE.

ITEC Asia-Pacific 2018 - 2018 IEEE Transportation Electrification Conference and Expo, Asia-Pacific: E-Mobility: A Journey from Now and Beyond

Maximum Power Output from a Solar PV Array under Partially Shaded Conditions

The paper presents the development of a new device for measuring continuous pulse pressure waveforms (PPW) from the radial artery via applanation tonometry. The development focuses on improved accuracy, open and affordable design using off-the-shelf components, and greater user control in setting operational and calibration parameters to address user variability. The device design parameters are optimized through a tissue device interaction study based on a computational model. The design incorporates modular components and includes a sensor module for arterial flattening and pressure pickup, a differential screw mechanism and a related algorithm for controlled stepwise motion and data collection during flattening, and a brace for wrist-flexion adjustment. Maximum pulse amplitude (PA) was used as an indicator of the optimum level of arterial flattening for recording the PPW. The PPW was observed to distort due to changes in parameters like gel-head placement, hold-down pressure (HDP), and wrist extension. The pressure waveforms collected using the device were validated using limited data against established products and showed good correlation within 61.96 standard deviation of the mean difference in a Bland-Altman plot. This paper thus details the development of a simple and validated mechanical design to measure PPW using arterial tonometry. © 2018 by ASME.

Journal of Medical Devices, Transactions of the ASME

A novel modular tonometry-based device to measure pulse pressure waveforms in radial artery

The rising energy demand and climate change issues have warranted the inclusion of renewable energy resources with existing conventional fuel based generation system. The intermittent renewable generation require adequate battery support in order to minimize load deficit issues in electrical grid. Hence, an attempt has been made in this paper to formulate a short term deterministic Unit Commitment problem in renewable integrated environment with battery storage. Ten thermal generators are scheduled with a 500 MW wind energy generation system supported by 200 MWh battery with backup of four hours. A three stage solution methodology is evolved involving hybrid Particle Swarm Optimization (PSO) technique to provide techno-economic solution to this complex optimization problem. The charge/ discharge scheduling of battery energy storage integrated to wind generation system is taken up as a co-optimization problem. The generation of battery energy storage integrated wind energy system is so scheduled that it relieves the costlier thermal generating units in the most economic manner. © 2018, International Journal of Renewable Energy Research.

International Journal of Renewable Energy Research

Optimized generation scheduling of thermal generators integrated to wind energy system with storage

Wireless Power Transfer System (WPTS) is gaining more attention across low power to high power applications. It is a convenient, safer, reliable, and user-friendly solution to wireless Electric Vehicle (EV) charger users. In WPTS, large air-gap between coils may cause high leakage of magnetic fields and it may also lower the coupling factor (k). In such systems, selection of coil structure and core configuration plays a key role to reduce the magnetic leakage. In this paper, a thorough mathematical analysis of various coil structures has been presented and observed the change in inductance from one coil structure to another. A finite element method is used in this paper to study the effect of coil structure on self-inductance, mutual inductance and coupling factor between the coils. This paper also provides the numerous core configurations, which have been added to WPTS and simulated to find its effect on power transfer efficiency between transmitter and receiver. The analysis on various coil-core configurations are performed for distinct air gaps between the transmitter and the receiver and found the supreme coil-core configuration to achieve the better coupling between them. © 2017 IEEE.

2017 IEEE Transportation Electrification Conference, ITEC-India 2017

A study on effect of coil structures and core configurations on parameters of wireless EV charging system

The history, culture, current and future socioeconomic status and environmental sustainability of India and its people are intricately linked to the water resources which are available from dams. These water resources available through dams are one of the main sources available for the usage to industries, livestock, irrigation etc. and there is a critical need to ensure the safety of the water level at these dams against any natural or anthropogenic threats and to develop an effective Water Level Management system using IoT. This paper gives an outline for the development of an information system based on the existing systems with the utilization of some sensors and IoT. This paper also proposes a novel idea of collecting and sharing real-time information about water levels to an authorized central command center through far field communication. The authorized central command center then takes a call whether to release the water by opening dam gates or keep them closed. By doing so, the operation of dams all over the country is centralized and automatized. © 2018 IEEE.