Electrical Engineering

This paper introduces a simplified inverter circuit using a single dc source and an H-bridge with a least possible number of “switching devices”. This topology does not employ multiple “dc sources”, which enhances the reliability of the configuration. The topology consists of two parts, namely: “Level generation parts” as well as “Polarity generation parts”, it is the mixture of some of the switching devices, DC-link capacitor and a single DC source completes the part of level generation. The H-bridge in the proposed structure produces the polarity generation part. A detailed explanation of the modulation system and operating modes of the proposed framework are discussed. Finally, in the MATLAB/SIMULINK platform, the projected network topology is simulated and the outcomes are presented.

Electric vehicles contribute a major role in building an eco-friendly environment. Li-ion batteries are most widely used in electric vehicles. It is very important to maintain the operation of Li-ion batteries within their “safety operation area (SOA)”. Hence implementing a battery management system (BMS) becomes a necessity while using Li-ion batteries. This paper proposes an intelligent BMS for electric vehicles using proportional integral derivative (PID) control action along with artificial neural network (ANN). It prefers the improved pulse charging technique. The design consists of a battery pack containing four 12 V Li-ion batteries, MOSFETs, Arduino Uno, a transformer, a temperature sensor, a liquid-crystal displays (LCD), a cooling fan, and four relay circuit are used. Arduino Uno is used as a master controller for controlling the whole operation. Using this design approximately 38 minutes are required to fully charge the battery. Implementation results validate the system ...

Solar energy produced by concentrated solar heat collector panels requires tracking mechanisms for a more optimal direction. This paper presents the design and construction of a low energy solar tracking control system with telecontrol facilities. To accelerate the movement of the panel in always adjusting itself to the direction of the sun, a combination of the timer and light sensor was used. In this control system, the reference signal is taken from two pieces of light sensors while the feedback is taken from the position and temperature sensors. The program has been developed using C language and was implemented on the microcontroller ATMega8535 as the brain of the system. Telecontrol facilities for monitoring the data to a computer uses transceiver modules via RS-232 connection. A DC motor having power capacity of 0.74 watts was used and was clutched with 1:7,300 gearbox ratio. Experiments on light sensor characteristics and simulated movement of the panel were carried out. Fro...

Kendali putaran motor DC dapat dilakukan dengan menggunakan perintah suara melalui voice recognition. Perintah suara dapat mengakibatkan motor DC berputar ke kanan kekiri atau juga berhenti. Penelitian ini bertujuan untuk melakukan desain dan implementasi sistem kendali putaran motor DC dengan menggunakan voice recognition dan internet of things (IoT) sehingga putaran motor DC dapat dikendalikan dari jarak jauh dengan perintah suara. Sistem dirancang menggunakan perangkat keras berupa voice recognition berbasis IoT yaitu Echo Dot dan Google Assistant, NodeMCU+ESP8266, driver motor DC, dan Motor DC. Sedangkan perangkat lunak dan aplikasi yang digunakan adalah Arduino IDE dan Aplikasi Adafruit.io dan IFTTT. Perintah suara yang diterima oleh perangkat voice recognition akan diteruskan ke IFTTT yang terhubung dengan aplikasi Adafruit.io. Data dari Adafruit.io yang merupakan aplikasi IoT akan terhubung dengan hardware NodeMCU+ESP8266 yang akan memberikan perintah pada driver motor DC unt...

Project RAVEN is a research project at Memorial University of Newfoundland, whose aim is to establish an Uninhabited Aerial Vehicle (UAV) presence off the Eastern coast of Canada in support of maritime surveillance operations conducted by manned aircraft. Until recently, the use of radar on the small low altitude long endurance (LALE) class of UAV being considered for this role was thought impossible due to restrictive payload size and weight limits. However, RAVEN has acquired the use of a small Synthetic Aperture Radar (MicroSAR) that will be integrated onto the Aerosonde UAV, through a cooperative research project with Brigham Young University (BYU) in Utah, and the University of Colorado at Boulder. The intent is to use the MicroSAR system on an Aerosonde to take high-resolution imagery of sea ice off the Newfoundland Coast in 2007. The end application for such technology includes monitoring of sea ice changes in the Arctic, support for the Iceberg Patrol in the North Atlantic, ...

Cell imbalance can cause negative effects such as early stopping of the battery charging and discharging process which can reduce its capacity. In the previous active balancing research, the energy used for the balancing process was taken from the cell or battery pack, resulting in drop of electric vehicle driving range. In this paper, a cell charger based battery balancing system is proposed with a reduction in the number of switches. The use of a cell charger aims to increase the usable energy of the battery pack, since the energy used for the balancing process is taken directly from the grid. The use of fewer switches aims to reduce the cost and space used on the battery management system (BMS) hardware. The charger used for the balancing process has a maximum current of 3 A and a maximum voltage of 3.65 V while the number of switches used is n+5 for n batteries. A 15S1P 200 Ah LiFePO4 battery pack consists of 15 cells used for testing purpose. The test results show that the time...

Cell imbalance has always happened in the series-connected battery. Series-connected battery needs to be balanced to maintain capacity and maximize the batteries lifespan. Cell balancing helps to dispart energy equally among battery cells. For active cell balancing, the use of a DC-DC converter module for cell balancing is quite common to achieve high efficiency, reliability, and high power density converter. This paper describes the implementation of a LiFePO4 battery charger based on the DC-DC converter module used for cell balancing application. A constant current-constant voltage (CC-CV) controller for the charger, which is a general charging method applied to the LiFePO4 battery, is presented for preventing overcharging when considering the nonlinear property of a LiFePO4 battery. The prototype is made up with an input voltage of 43V to 110V and the maximum output voltage of 3.75V, allowing to charge a LiFePO4 cell battery and balancing the battery pack with many cells from 15 ...

The ATC determination method in this study uses line  thermal constraints by calculating reactive power flow, and using Linear Power Transfer Distribution Factor. The ATC determination considers the magnitude of the voltage magnitude and the static voltage stability of each bus after the power transfer simulation is performed. Static voltage stability is calculated using the L Index. The results showed that the transfer of power equal to the ATC value in an electric power system caused a decrease in voltage stability or an increase in the L index value on the receiving bus on average 19 times the initial loading condition, even though it was still at a stable level. While the receiver bus voltage magnitude has decreased

Generalized frequency division multiplexing (GFDM) is a waveform for the next-generation communication systems to succeed in the drawbacks of orthogonal frequency division multiplexing (OFDM). The symbols of users are transmitted with the time- and frequency-shifted versions of a prototype filter. According to filtering operation, the computational complexity and processing load are high for the devices that suffer from energy consumption. The communication systems are required to support the new generation devices that need low energy consumption and low latency issues. Motivated by such demands of the next-generation communication system, we propose a novel GFDM waveform that we call hexagonal GFDM. The contributions of the hexagonal GFDM are that it: (i) supports short transmission time based on its hexagonal time–frequency allocations; and (ii) provides low latency communication with low computational complexity manner. Furthermore, we design a transmitter and receiver structure...

La recuperación de información multimedia es uno de los retos que actualmente se afrontan en el entorno de la web o en grandes colecciones de objetos multimedia (audio, video, imágenes y textos). En este artículo se presenta la experimentación realizada para mejorar la calidad de la búsqueda en una colección de imágenes anotadas como es IAPR TC-12. Se muestra cómo la fusión multimedia mejora los resultados de búsquedas monomodales basadas solo en texto o en imagen, y además se propone una aproximación semántica ...

This paper presents a fully integrated 0.18 μm CMOS Low-Dropout (LDO) Voltage Regulator specifically designed to meet the stringent requirements of a battery-operated impedance spectrometry multichannel CMOS micro-instrument. The proposed LDO provides a regulated 1.8 V voltage from a 3.6 V to 1.94 V battery voltage over a −40 °C to 100 °C temperature range, with a compact topology (<0.10 mm² area) and a constant quiescent current of only 7.45 μA with 99.985% current efficiency, achieving remarkable state-of-art Figures of Merit (FoMs) for the regulating⁻transient performance. Experimental measurements validate its suitability for the target application, paving the way towards the future achievement of a truly portable System on Chip (SoC) platform for impedance sensors.

This paper presents a performance evaluation of two solutions to reduce computational burden of the traditional Weighted Least Squares Algorithm for power system state estimation: Simplified methods SWLS1 / SWLS2 based on full constant matrices and Fast decoupled FDWLS based on decoupled constant matrices. First, the algorithms were tested on IEEE 14 and 118 bus transmission systems. Second, the solutions were tested on a rural distribution feeder to evaluate the response of the algorithms to high R/X ratio. Results show that for transmission systems, FDWLS is the fastest method but more sensitive to erroneous measurements. Simplifications considered in FDWLS, are not valid in distribution systems with high R/X ratio this results in slowing down the algorithm convergence speed considerably compared to SWLS2 which performs well. SWLS2 algorithm presents a promising solution to reduce computation time for application in future smart grid.

Smart as a Bug: A Computational Model of Learning in the Moth Olfactory Network, with Applications to Neural Nets Charles Boise Delahunt Co-Chairs of the Supervisory Committee: Professor J. Nathan Kutz Applied Mathematics Professor Eve Riskin Electrical Engineering The moth olfactory network is one of the simplest biological neural systems capable of Learning. It is thus ideal for exploring how learning occurs. The network, which includes the antenna lobe, mushroom body, and ancillary structures, contains several key structural motifs widespread in biological neural systems and of great interest. These include cascading networks, large dimension shifts from stage to stage, high-dimensional sparse codings of data, randomness, Hebbian (“fire together, wire together”) plasticity, and octopamine stimulation as a vital part of the learning mechanism. While these components are widespread in natural neural systems, they are largely absent from the engineered neural nets of machine learnin...

En el presente documento se propone un analisis de la eficiencia de estructuras de devanado de motores monofasicos, mediante el modelamiento de campos magneticos utilizando la herramienta FEMM que realiza el analisis mediante elementos finitos. En el documento, en primer lugar se realiza el modelamiento de la maquina monofasica de arranque por capacitor mediante las matrices de secuencia. Se realiza los ensayos de cortocircuito y vacio. Luego se analizan las simulaciones realizadas para las diferentes estructuras de devanados de la maquina. Tambien se determinan las curvas de eficiencia y par electrico de la maquina. Finalmente se construye la maquina que mejores resultados dio tanto en eficiencia como en par.

Shifting table (manipulator) terletak pada setiap stand, dari stand 1 sampai dengan stand 5 yang berfungsi sebagai pengatur dan penyearah posisi baja untuk masuk kedalam area cooling bed serta kemudian langsung diarahkan kebagian produksi. Pada shifting table (manipulator) dibutuhkan sistem kendali otomatis menggunakan Programmable Logic Controller, secara jenisnya PLC yang digunakan pada sistem kendali tersebut yaitu Siemens S7-1500. Dengan metode observasi (pengamatan) dilapangan terhadap semua peralatan yang dikerjakan dan dengan metode literatur dapat diketahui sistem kendali dari manipulator. Dari hasil penelitian manipulator dapat diketahui pengendalian ini bertujuan untuk mengaktifkan shifting table (manipulator) supaya dapat bekerja secara otomatis kemudian digunakan untuk mengetahui ukuran baja yang akan diarahkan ke tahapan selanjutnya sampai dengan tahap produksi (finishing) dan akan ditampilkan pada layar monitor di HMI (Human Machine Interface).  

Firm growth is an important indicator of a thriving economy. Although the determinants of firm growth have been studied in various disciplines, an integrated analysis is still lacking. Many determinants of firm growth are summarized and classified into three dimensions: individual, organizational, and environmental determinants. The present paper attempts to provide an integrated analysis on the determinants of firm growth. It gives an opportunity to investigate the determinants of firm growth in a comprehensive way. The close-ended questionnaire was developed from standard questions of relevant literature as a research instrument. The sample size taken for the research is of 110 IT firms entrepreneurs. Among the individual determinants, need for achievement, risk taking propensity and self-efficacy are positively conducive to firm growth. Among the organizational determinants, formulation, preparedness to grow, organizational learning, financial performance have positive impacts on...

An analysis of the method for ensuring the sinusoidality of the output voltage in power generation systems with self-commutated voltage inverters under the requirements of the international standard IEEE-519 is presented. In a number of programs, especially low-power generation systems, a low-cost solution is needed to provide the sinusoidal waveform of the output voltage with the total harmonic distortion of 5 %. This solution is to use two-level voltage inverters with an output sine LC filter. However, the feature of the sine filter with the frequency converter is that the PWM frequency affects the spectrum of higher harmonics of the output voltage. In addition, there is the starting current of the filter capacitor, which can disable the power switches of the voltage inverter. The developed method for calculating the values of the LC filter with the two-level voltage inverter in the PWM mode is presented meeting the requirements of the international standard IEEE-519, taking into ...

Abstrak—Proses material handling yang menuntut ketepatan posisi yang tinggi sangat banyak digunakan di industri manufaktur, misalnya pemindahan benda kerja dari satu 1 jig ke jig yang lain dalam rangkaian proses pemesinan otomatis. Oleh karena itu, Laboratorium Otomasi Industri di Prodi Mekatronika Politeknik Manufaktur Astra sangat perlu untuk memiliki alat peraga pengendalian pergerakan axis agar dapat melakukan simulasi pengaturan posisi dengan tepat. Penelitian dilakukan melalui tahapan penentuan perancangan sistem sesuai capaian pembelajaran dan kurikulum Prodi Mekatronika, pemilihan komponen, perakitan hardware, pemrogramman software dan pengujian. Motor stepper dipilih pada penggerak axis dengan pertimbangan harga dan prinsip operasional yang sangat mendasar. Ditambah dengan encoder sebagai pendeteksi sejauh mana axis telah bergeser, sedangkan pengendali utama menggunakan Programmable Logic Control (PLC). Alat peraga yang dikembangkan telah mampu melakukan simulasi pengendali...

Aromaticity has already been shown to play a role in the fluorination of fullerenes and several studies have been reported concerning the aromaticity of carbon nanotubes.2 In this work, we have first examined the influence of nanotube curvature and length on the nucleus independent chemical shifts (NICS), and secondly the role of the aromaticity in the fluorination process of the nanotube surface.3 In particular, the influence of local aromaticity on the addition mechanism is discussed.4