Engineering Commons^™

Grid Connected Roof Top Solar Power Generation: A Review, Radhey Shyam Meena

Radhey Shyam Meena

India is blessed with rich solar energy and if exploited efficiently, the country has the potential of producing trillionkilowatts of electricity. Sunlight is converted to electricity directly when made to fall on solar photovoltaic (SPV) modules. Systems /devices are made for various applications based on SPV modules connected with suitably designed power conditioning units for meeting electricity requirements. These systems/devices are designed to work in offgrid mode (usually supported with batteries to allow use when sunlight is low or during night). In recent years solar PV systems became viable and attractive. Utility scale plants are being set up worldwide with …

Static Security Enhancement And Loss Minimization Using A Simulated Annealing Based Approach, Almoataz Youssef Abdelaziz

Almoataz Youssef Abdelaziz

A developed algorithm for optimal placement and sizing of thyristor controlled series capacitors (TCSC’s) for enhancing the static security of power system and minimizing the overall power system loss is presented in this paper. A procedure to determine the optimal locations and sizes of the thyristor controlled series capacitors is illustrated and presented. The locations are determined by evaluating contingency sensitivity index (CSI) for a given power system branch for a given number of contingencies. Optimal sizes of TCSC’s are determined by the optimization technique of simulated annealing (SA), where TCSC’s settings are chosen to minimize the overall power system …

Modeling Of Wide-Bandgap Power Semiconductor Devices—Part Ii, Kang Peng

Kang Peng

Energy Conservation Day: Symbolism Doesn’T Pay, Hippu Salk Kristle Nathan

Hippu Salk Kristle Nathan

The much publicised panting competition at school level on the occasion of Energy Conservation Day was a good effort to send message to consumers to influence their energy consumption behaviour. But the effect is minuscule.

As a child one might have walked or cycled to school. But as a breadwinner, once energy related decisions largely get influenced by one's income level and opportunities and restrictions.

Optimal Scheduling Of A Microgrid With Demand Response Resources, Daniela Proto, Guido Carpinelli, Fabio Mottola

Daniela Proto

A Portable Wireless Particulate Sensor System For Continuous Real-Time Environmental Monitoring, James A. Hall Jr., Sin Ming Loo, Dale Stephenson, Ross Butler, Michael Pook, Joshua Kiepert, Jordan Anderson, Nicholas Terrell

Dale J. Stephenson

Airborne particulate matter has been shown to be associated with morbidity and mortality, and may interfere with certain sensitive experiment. Understanding the levels and movements of particulate matter in an enclosed space can lead to a reduction in the impact of this material on health and experimental results. A system of environmental sensors including particulate matter, selected gasses, humidity, temperature, and pressure can be used to assist in tracking air movement, providing real-time mapping of potential contaminants as they move through a space. In this paper we present a system that is capable of sensing these environmental factors, collecting data …

H-Matrix-Based Fast Direct Finite Element Solver For Large-Scale Electromagnetic Analysis, Haixin Liu, Dan Jiao

Haixin Liu

In this work, we prove that the sparse matrix resulting from a finite-element-based analysis of electrodynamic problems can be represented by an H-matrix without any approximation, and the inverse of this sparse matrix has a data-sparse H-matrix approximation with error well controlled. Based on this proof, we develop an H-matrix-based direct finite-element solver of O(kNlogN) memory complexity and O(k2Nlog2N) time complexity for solving electromagnetic problems, where k is a small variable that is adaptively determined based on accuracy requirements, and N is the number of unknowns. Both inversebased and LU-based direct solutions are developed. The LU-based solution is further accelerated …

Lna Integrates Fast Shutdown Function, Chin-Leong Lim

Chin-Leong Lim

To minimize dead time in time domain duplex (TDD) transceiver, reception should ideally commence as soon as transmission ends. However, the low noise amplifier (LNA), which is typically shutdown during transmission to prevent device damage and receiver overload, can exhibit a turn-on delay. In older implementations, the shutdown function is external to the LNA device. So, one way to reduce part count and to miniaturize this class of LNA is to integrate the LNA and shutdown function in a microwave monolithic integrated circuit (MMIC). The integration also allows the shutdown circuit to be connected to the LNA at an optimum …

Power Variation With Electret Surface Potential And Frequency Of Vibration In Vertical Vibration Based Cantilever-Electret Micro-Power Generation, Innovative Research Publications Irp India, Akin-Ponnle A.E, Ponnle A.A, Falaki S.O.

Innovative Research Publications IRP India

A cantilever-electret based electrostatic micro-power generator for energy harvesting was set up in which Cyclic Transparent Optical Polymer (CYTOP) was used as the electret, and the upper electrode was made in form of an Ashaped cantilever which was fabricated from materials of copper with embedded glass epoxy. The cantilever was vibrated in the vertical direction in close to contact point mode of operation. Experimental result showed that the average output power increases with increasing electret surface potential, and the minimum distance to contact point decreases with increasing electret surface potential. Also, variation of output power with frequency was investigated by …

Desert Rhex Technical Report: Jornada And White Sands Trip, Sonia Roberts, Jeff Duperret, Aaron M. Johnson, Scott Van Pelt, Ted Zobeck, Nick Lancaster, Daniel E. Koditschek

Sonia F. Roberts

Researchers in a variety of fields, including aeolian science, biology, and environmental science, have already made use of stationary and mobile remote sensing equipment to increase their variety of data collection opportunities. However, due to mobility challenges, remote sensing opportunities relevant to desert environments and in particular dune fields have been limited to stationary equipment. We describe here an investigative trip to two well-studied experimental deserts in New Mexico with D-RHex, a mobile remote sensing platform oriented towards desert research. D-RHex is the latest iteration of the RHex family of robots, which are six-legged, biologically inspired, small (10kg) platforms with …

A Model For Rapid Charging Events On International Space Station, Debrup Hui

Debrup Hui

Surface charging by plasma can be a serious issue for any spacecraft. Though significant charging is not observed in all spacecrafts at all times, it only requires a single episode of extreme charging to result in serious damage. The International Space Station (ISS) is an interesting platform to study these charging effects because of its size and relatively high voltage systems. Of the many kinds of charging observed on ISS, the rapid charging events during solar eclipse exit in a low-density ionosphere is not yet understood. This report is an investigation to understand this phenomenon. This report proposes a simple …

Review Of Normal And Infrequent In-Feed Loss Risks In The Transmission System Of Oman, Omar H. Abdalla, Adil Al-Busaidi, Hilal Al-Hadi, Hisham A. Al-Riyami, Ahmed Al-Nadabi

Omar H. Abdalla

The paper presents technical studies performed to review the values of the Normal Infeed Loss Risk (NILR) and Infrequent Infeed Loss Risk (IILR) in the Transmission System Security Standard (TSSS). The objective is to facilitate the connection of the largest power station in Oman, which is Sur 2000 MW IPP, to the Main Interconnected Transmission System (MITS), while complying with the requirements of the TSSS. The full output of 2000 MW of Sur power plant is expected to available in 2015; therefore the MITS model of 2015 is used in the studies using the DIgSILENT professional software. The model includes …

Characterisation Of Large Disturbance Rotor Angle And Voltage Stability In Interconnected Power Networks With Distributed Wind Generation, Lasantha Meegahapola, T Littler

Dr Lasantha G Meegahapola

Wind generation in highly interconnected power networks creates local and centralised stability issues based on their proximity to conventional synchronous generators and load centres. This study examines the large disturbance stability issues (i.e. rotor angle and voltage stability) in power networks with geographically distributed wind resources in the context of a number of dispatch scenarios based on profiles of historical wind generation for a real power network. Stability issues have been analysed using novel stability indices developed from dynamic characteristics of wind generation. The results of this study show that localised stability issues worsen when significant penetration of both conventional …

Capability Constraints To Mitigate Voltage Fluctuations From Dfig Wind Farms When Delivering Ancillary Services To The Network, Lasantha Meegahapola, S Perera

Dr Lasantha G Meegahapola

Majority of the wind power resources are typically sited at remote locations in power networks and generated power is transmitted through rural transmission corridors to load centres. With increased penetration level of the wind generation there is an increased requirement to provide ancillary services from distributed wind power resources, hence they are operated under different control strategies to provide ancillary services to the network. The control strategies and capability characteristics will significant impact on voltage fluctuations in distribution networks. This paper presents a comparative analysis between different wind generator control strategies (i.e. power factor control strategy, voltage control strategy and …

Implementation Of Multi Mode Aes Algorithm Using Verilog, Innovative Research Publications Irp India, P Penchala Reddy, Dr.V. Thrimurthulu, K. Jagadeesh Kumar

Innovative Research Publications IRP India

Increasing need of high security in communication led to the development of several cryptographic algorithms hence sending data securely over a transmission link is critically important in many applications. NIST in the beginning selected Rijndael within October 2000 and formal adoption as being the AES standard started in December 2001. FIPS PUB 197 explains a 128-bit block cipher making Ause of a 128, 192, or 256-bit key. In cryptography, modes of operation enable the repeated and secure use of a block cipher under a single key. This paper presents implementation of multi mode AES algorithm with three modes ECB, CBC …

On Modeling Eavesdropping Attacks In Wireless Networks, Xuran Li, Jianlong Xu, Hong-Ning Dai, Qinglin Zhao, Chak Fong Cheang, Qiu Wang

Hong-Ning Dai

This paper concerns the eavesdropping attacks from the eavesdroppers’ perspective, which is new since most of current studies consider the problem from the good nodes’ perspective. In this paper, we originally propose an analytical framework to quantify the effective area and the probability of the eavesdropping attacks. This framework enables us to theoretically evaluate the impact of node density, antenna model, and wireless channel model on the eavesdropping attacks. We verify via extensive simulations that the proposed analytical framework is very accurate. Our results show that the probability of eavesdropping attacks significantly vary, depending on the wireless environments (such as …

Estimating Effective Connectivity From Fmri Data Using Factor-Based Subspace Autoregressive Models, Chee-Ming Ting Phd, Abd-Krim Seghouane Phd, Sh-Hussain Salleh Phd, Alias M. Noor Phd

Chee-Ming Ting

Refractory Plasmonics With Titanium Nitride: Broadband Metamaterial Absorber, W Li, U. Guler, N. Kinsey, G. Naik, A. Boltasseva, J. Guan, V Shalaev, A. Kildishev

U. Guler

A high-temperature stable broadband plasmonic absorber is designed, fabricated, and optically characterized. A broadband absorber with an average high absorption of 95% and a total thickness of 240 nm is fabricated, using a refractory plasmonic material, titanium nitride. This absorber integrates both the plasmonic resonances and the dielectric-like loss. It opens a path for the interesting applications such as solar thermophotovoltaics and optical circuits.

Modeling And Estimation Of Single-Trial Event-Related Potentials Using Partially Observed Diffusion Processes, Chee-Ming Ting Phd, Sh-Hussain Salleh, Z. M. Zainuddin, Arifah Bahar

Chee-Ming Ting

This paper proposes a new modeling framework for estimating single-trial event-related potentials (ERPs). Existing studies based on state-space approach use discrete-time random-walk models. We propose to use continuous-time partially observed diffusion process which is more natural and appropriate to describe the continuous dynamics underlying ERPs, discretely observed in noise as single-trials. Moreover, the flexibility of the continuous-time model being specified and analyzed independently of observation intervals, enables a more efficient handling of irregularly or variably sampled ERPs than its discrete-time counterpart which is fixed to a particular interval. We consider the Ornstein–Uhlenbeck (OU) process for the inter-trial parameter dynamics and …

Non-Linear Collision Analysis, Thomas Eisenbarth, Xin Ye, Cong Chen

Thomas Eisenbarth

As an unsolved issue for embedded crypto solutions, side channel attacks are challenging the security of the Internet of things. Due to the advancement of chip technology, the nature of side channel leakage becomes hard to characterize with a fixed leakage model. In this work, a new non-linear collision attack is proposed in the pursuit of the side channel distinguishers with minimal assumption of leakage behavior. The attack relies on a weaker assumption than classical DPA: it does not require a specific leakage model. The mechanism of collision generation enables independent recovery of partial keys so that for the first …

Suboptimal Mppt Control For Power Management In Pv-Diesel Remote Area Power Supply Systems, Lasantha Meegahapola, Y J Tan, K M Muttaqi

Dr Lasantha G Meegahapola

Maximum power point tracking (MPPT) is commonly being used in solar-photovoltaic (PV) power generation systems to maximise solar energy extraction. In this paper it is proposed to operate the solar-PV system at the suboptimal MPPT to manage power balance in a remote area power supply (RAPS) system. This is performed based on three different operating modes: 1) Frequency control mode; 2) Active power control mode; 3) MPPT control mode. The operating modes are decided based on the load level and the operating mode of the diesel generator (i.e. synchronous condenser mode or generator mode). This power management strategy balances the …

Dispatch Strategy To Minimise Uncertainty In Wind Power Generation In The Australian National Electricity Market, Lasantha Meegahapola, Amila Wickramasinghe, A P Agalgaonkar, S Perera

Dr Lasantha G Meegahapola

With increased penetration of wind power, scheduling generators to meet the forecast demand of a power system is becoming an increasingly challenging task for the system operators. Uncertainty associated with the generation expected from wind plants adds to the load demand uncertainty, making it necessary to retain additional reserves to maintain the balance between demand and supply of power. In the Australian national electricity market (NEM), sophisticated wind forecasting techniques are employed to reduce the uncertainty in wind generation. Despite being able to project the contribution of wind power to a reasonable accuracy, wind power plants are currently not considered …

Influence Of Oxygen On Electronic Properties Of Nanocrystalline Silicon, Shantan Kajjam

Shantan Kajjam

Nanocrystalline Silicon (nc-Si) is an important material for photovoltaic device applications. Its excellent absorption, low defect levels and many other interesting properties help build high efficiency solar cells. Its structure is very complex and is sensitive to contaminants and fabrication processes. It needs a careful study so that a maximum outcome can be attained from the material. Nc-Si is highly prone to be defective and oxygen is one of the major sources of the defects. In this thesis, systematic analysis of the fundamental properties of oxygen doped & boron compensated nc-Si are illustrated. Thin film solar cells were fabricated using …

Characterization Of Gas Turbine Lean Blowout During Frequency Excursions In Power Networks, Lasantha Meegahapola, D Flynn

Dr Lasantha G Meegahapola

While gas turbines are popular in power networks due to reduced emissions and economical operation, their frequency response characteristics are substantially different from other conventional generation technologies; hence, gas turbine dynamics may influence system stability during significant frequency excursions. This study characterizes the impact of gas turbine combustor lean blowout (LBO) while considering large frequency excursions and, in particular, during short-circuit faults. Studies have shown that combined-cycle gas turbines are more vulnerable to an LBO condition during short-circuit events when they operate at rated power output. A sensitivity analysis was also carried out against a number of factors influencing the …

Emerging Role Of Photovoltaics For Sustainably Powering Underdeveloped, Emerging, And Developed Economies, Rajendra Singh, Amir A. Asif, Ganesh K. Venayagamoorthy, Akhlesh Lakhtakia, Mahmoud Abdelhamid, Githin F. Alapatt, David A. Ladner

Mahmoud M Abdelhamid

With the advent of low-cost solar photovoltaic (PV) panels and our ability to generate, store, and use electrical energy locally without the need for long-range transmission, the world is about to witness transformational changes in electricity infrastructures. The use of DC electricity enhances systemwide efficiency. DC microgrids and nanogrids powered by solar PV systems and gigawatt batteries for electricity storage can sustainably power the needs of all human beings equitably and empower every individual. Ultralarge-scale manufacturing of PV systems and batteries, a vertically integrated business model, and a targeted monetary policy of quantitative easing can rapidly power all human activities.

Sptf: Smart Photo-Tagging Framework On Smart Phones, Hao Xu, Hong-Ning Dai, Walter Hon-Wai Lau

Hong-Ning Dai

Smart phones, as one of the most important platforms for personal communications and mobile computing, have evolved with various embedded devices, such as cameras, Wi-Fi transceivers, Bluetooth transceivers and sensors. Specifically, the photos taken by a smart phone has the approximate or even equivalent image quality to that of a professional camera. As a result, smart phones have become the first choice for people to take photos to record their ordinary life. However, how to manage thousands of photos on a smart phone becomes a challenge. In this paper, we propose a new architecture in terms of Smart Photo-Tagging Framework …

Development Of Impedance Spectroscopy Based In-Situ, Self-Calibrating, On-Board Wireless Sensor With Inbuilt Metamaterial Inspired Small Antenna For Constituent Detection In Multi-Phase Mixtures Like Soil, Gunjan Pandey

Gunjan Pandey

Real time and accurate measurement of sub-surface soil moisture and nutrients is critical for agricultural and environmental studies. This work presents a novel on-board solution for a robust, accurate and self-calibrating soil moisture and nutrient sensor with inbuilt wireless transmission and reception capability that makes it ideally suited to act as a node in a network spread over a large area. The sensor works on the principle of soil impedance measurement by comparing the amplitude and phase of signals incident on and reflected from the soil in proximity of the sensor. The permittivity of the soil dielectric mixture which is …

Evaluation Of On-Board Photovoltaic Modules Options For Electric Vehicles, Mahmoud M. Abdelhamid

Mahmoud M Abdelhamid

This paper presents an overview of different commercial photovoltaic (PV) module options to power on-board electric vehicles (EVs). We propose the evaluation factors, constraints, and the decision-making criteria necessary to assess the suitability of this PV module for this application. The incorporation of quality function deployment (QFD) and the analytical hierarchy process (AHP) is the decision-making methodology used in this study. Our approach is innovative and robust in that the evaluation depends upon data collected from PV manufactures datasheets. Unlike traditional research, a hybrid AHP and QFD innovative decision-making methodology has been created, and current commercial PV market data for …

Inferring The Global Cosmic Dust Influx To The Earth’S Atmosphere From Lidar Observations Of The Vertical Flux Of Mesospheric Na, Chester S. Gardner, Alan Z. Liu, Dan Marsh, Wuhu Feng, John Plane

Alan Z Liu

The Gasday Project At Marquette University: A Learning Laboratory In A Functioning Business, Ronald H. Brown, Thomas F. Quinn, George Corliss, Jay R. Goldberg, Mark L. Nagurka

George F Corliss

No abstract provided.