電気・電子システムジャーナル

The Uganda power network has suffered various transformer overloads which have reduced power availability and utility income generation. Although frequency monitoring ensures system stability and calls for the Under Frequency Load Shedding scheme, other conditions that threaten power system stability like the loss of a tie line, overload trip of a power transformer, and overload trip of a transmission line need to be automated as well. This will not only improve reliability and continuity of service but also fast decision making, reduce the blackout zone, unnecessary load shedding, and minimal downtime. This paper presents a load management scheme that performs automatic load monitoring and feeder restoration by strictly following the set threshold values using PCM600, an ABB tool. The 11KV feeder load shedding hierarchy was strictly selected according to utility income-priority, strategic supply and safety. The logic configuration from PCM600 was validated and the Generic Object Oriented Substation Events (GOOSE) report was published. The Configured IED Description (CID) file from each IED (in PCM600) was saved in Substation Configuration Language (SCL) format and imported into IEDScout to simulate the IEC61850 communication. The simulation using IEDScout achieved a 500ms GOOSE messaging sequence and the traffic on the Ethernet cable was captured and analyzed using WireShark, a graphic user interface network protocol. A cost benefit ratio of 1.647 (greater than 1) was obtained to declared economically acceptable. This design caters for emergencies, i.e. very rare, non-continuous but possible and very catastrophic occurrences on the power system. Therefore this research provides an efficient solution to transmission line and transformer overload by automating downstream load-shedding and load restoration.

A scheme for multi scale based feature level image fusion for Multimodal medical images has been proposed here. The scheme is based on joint cascaded framework of Lifting wavelet transform (LWT) with Non subsampled contourlet transform (NSCT). These multiscale decomposition (MSD) methods are used back to back to decompose the images of different medical modalities. The low and high frequency coefficients obtained from two stage decompositions are fused according to different fusion rules. At first stage high frequency components (detail information) are fused by Karhunen –Loeve (KL) transform while low frequency by weighted superposition. Later on at second stage the max rule fusion method has been employed for both. Image reconstruction at the intermediary level is obtained by applying Inverse LWT (ILWT) and at final stage Inverse NSCT has been employed. Haar wavelet function is chosen here for its less computational cost property. The effectiveness of the proposed method (LWT-NSCT) is observed by enhanced values of assessment parameters of evaluation indices metric as compared to contemporary and popular transform based fusion methods. Now the attractive features of both transforms i.e. lifting and NSCT like sparse data representation, integer to integer mapping, high vanishing moments and saving of auxiliary memory are attractable features of this method.

Problems involving power quality is an often occurrence which comes as nonstandard voltage, frequency or current which result in a complete failure or dysfunction of an end user equipment. Sensitive industrial loads, distribution networks and some very important commercial operation suffer the most from these forms of distortions which may lead an outage which will in turn cost a significant financial loss. With redesigning and restructuring of power systems, the problem involving power quality is going to take a different phase. In developing countries like Nigeria, power frequencies and many other things that determine power quality varies and this will lead to a serious question, it is extremely important to take great steps towards this direction. In order to achieve an acceptable distortion, which is the sole purpose of this thesis by reducing the harmonics as well as improving the overall power quality of the system, three phase filters which filter harmonics were connected in parallel these filters will help in suppressing the higher order harmonics. Variants of Butterworth, Chebyshev and Cauer filters were used in MATLAB SIMULINK. HVDC line was also checked for harmonics and also to correct the overall power factor of the system.

Nowadays, as the supply of smart phones becomes dynamic and a variety of functions of smart phones and services based on internet is utilized, a wide range of applications are being developed and deployed. Smart phones are becoming more favourite companions to users than desktops or notebooks. Despite the speedy growth of smart phones and the application market, the exam hall plan which is currently being used is still in its primal forms. Previously developed exam hall plan check system uses a notice board which is placed in the college. This project proposes a system that is based on a QR code, which displays the exam hall details of the students before the beginning of each exam. The students will need to scan the code in order to confirm their exam hall. This helps to save the time and more ease to assemble in the scheduled manner.

A previously developed analytical thermal stress model is used for the assessment of the effect of the glasstransition
temperature (Tg) of the underfill encapsulant and the thickness of the underfill-solder composite bond (USCB)
on the induced stresses. The calculations were carried out for two Tg levels, above and below the operation and testing
temperature range for the flip-chip (FC) or the fine-pitch ball-grid-array (FPBGA) assembly with an USCB, and for two
thicknesses, 0.05 mm and 0.1 mm, of the USCB. Calculations indicated that the Tg level of the underfill material had a
significant effect on the induced stresses: the normal stresses in the USCB with a low-modulus (low Tg) underfill were
about half the stresses of the design with high-modulus (high Tg) underfill, and this was true for both thin (0.05 mm
thick) and thick (0.1 mm thick) USCB layers. As to the role of the USCB thickness, thicker USCBs exhibit somewhat
lower normal stresses, than thin layers, but the effect is insignificant. The maximum predicted shearing stresses occur
at the USCB/chip, and not at the USCB/substrate interface. This result is in agreement with the observed, in a number
of experiments, delaminations at the USCB/chip interface, and not at the USCB/substrate interface. The obtained data
indicate also that (in a way, contrary to the current practice) there is an incentive for using low Tg underfills, provided, of
course, that their adhesive strength is proven to be sufficient for the lower stress level. This is an important requirement,
of course, and might explain why electronic product manufacturers employ mostly high Tg underfills. As to the incentive
for using thicker USCBs, the increase in this thickness from 0.05 mm to 0.1 mm resulted in a minor relief in the normal
stress in the USCB for both high and low Tg underfills, but led to an appreciable relief in the interfacial stresses at the
USCB/chip interface, especially for high Tg underfills: the predicted stress relief in this case was as significant as 34%.
For low Tg underfills the stress relief was much lower, but still appreciable: about 19%. Thicker USCB layers could be
more effective, because, as has been shown in our earlier publications and confirmed experimentally, elevated stand-off
heights of solder joint interconnections are able to provide appreciable stress relief in the solder material by making the
bonding system more compliant. Indeed, for the thickness of 0.75 mm (impossible for FC designs, but rather typical for
FPBGA systems) the decrease in the normal stress acting in the USCB cross-sections is appreciable, and the decrease
in the shearing stress at the USCB/chip interface is as high as 70% in the case of high Tg underfill and even higher, 76%,
in the case of low Tg underfill. The employed analytical stress model used in this analysis can be used for the selection
of the adequate underfill material and establishing the appropriate USCB thickness at the design stage. It is noteworthy
that, as long as the linear approach is used and the induced stresses are proportional to the change in temperature, the
developed model can be used also in situations, when the underfill’s Tg is between the temperature extremes that the
assembly of interest experiences during its accelerated testing and in actual operation conditions.

With the proliferation of distributed generation technologies and renewable energy electric power system is
becoming more complex. In traditional grid system and current energy metering infrastructure line losses are growing
day by day. This project will enable smart net energy metering by using GSM technology, user will not only able to view
real time usage of energy but also will be able to sell excessive energy to utility which is produced in the vicinity of user.
Either Renewable or nonrenewable energy resources can be utilized and controlled remotely through mobile
application, the energy sold out to utility will be deducted from energy consumed from utility which enables dual way
smart net energy metering system. Net metering makes residential solar energy system ownership even more attractive
and affordable for many families. It can save homeowners hundreds more rupees per year on their utility bills, and it
makes the process of accounting for the energy flowing to and from the utility simpler and easier to administer.

Different protective devices types based on previous literature are discussed. Special attention is focused on metaloxide
surge arresters, their non-linear characteristics, models, factors affects on protective characteristics, effect and
behavior in working conditions. The paper presents the analysis of the influence of non-linear characteristic of protective
metal-oxide arrester on the overvoltage shape appeared on the protected transformer. The characteristic of the arrester
is approximated by power type function. As an example the overhead transmission line connected to transformer
through a busbar is considered. The line is characterized by their surge impedance and travel time and the transformer
by its surge impedance. The transformer is protected by protective device such as metal-oxide arrester connected in
parallel with it. The system of equations describing the overvoltage transmission line, transformer and the protective
device modeled by non-linear v-i characteristic, based on digital step-by-step solution is written. The computer modeling
software is used to solve the equations and compute overvoltage’s waveshape at transformer. The (v-i), (v-t), and (i-t)
characteristics obtained as the result of these computations are presented.

The paper uses Arduino Microcontroller to design a Modified Sine Wave Inverter. It employs Fourier transform to
mathematically analyse its harmonic contents. It was shown that by eliminating third harmonics present, distortions
can be reduced. The paper employs step by step methods to design various stages having, Transistor and MOSFET
switches. Arduino codes were written using digitaWrite() and delayMicroseconds() functions in its Integrated
Development Environment IDE to generate drive waveforms. It highlights how Arduino sketch could be compiled and
hex files generated for simulation in Proteus ISIS. Power Transformer Simulation technique was explained. It is believed
that proliferation of Inverter technology will enhance economic prosperity especially in the third world countries where
dearth of electrical energy is being experienced. The design includes Liquid Crystal Display for the display of generated
voltage and frequency. It is recommended that future improvement could be improvement in Liquid Crystal Display
functions with robust programming that would foster ease of interactions between the device and the users.

Multilevel inverter is an effective and practical solution for increasing power demand and reducing harmonics of ac waveforms. Such inverters synthesize a desired output voltage from several levels of dc voltages as inputs. This paper analyzes the performance of five level cascaded H-bridge multilevel inverter with reduce number of power switches. Further by reducing switches and increasing level will reduce filter cost & harmonic content. 5- Level cascaded H-bridge asymmetrical multilevel inverter topology requires 8 switches but in this new multilevel inverter it requires 6 switches in which same multilevel is obtained. Invariably switching losses and cost also reduced. In this paper only multilevel inverter circuitry will be studied. The performance has been analyzed by the MATLAB/Simulink.

This paper presents a practical three-dimensional (3-D) outdoor channel model for multi-user distributed massive multi-input multi-output (MU-DMMIMO). As the dimension of the antenna and the distance between transmitter and receiver increasing, the elevation angles will be more challenge, especially at the cell edge. In this paper, the beam pattern is assumed in the proposed channel model instead of the spherical wave front assumption used in current 3-D channel models. These include the far-field effects were done jointly with azimuth and elevation angles in different appearance clusters with various times of elevation and azimuth angle of departure and arrival on both the time and array axes. In addition, their impacts on MU-DMMIMO at the cell edge are investigated via statistical properties including a measurement of the path-loss power control on the non-stationary model of the user at the receiver. It is demonstrated that the proposed 3-D channel model is more accurate in characterizing real propagation channel when users are handovers at the cell edge.

Wireless power transmission is the way to transfer power without using wire. Wireless power transmission helps to connect those area where people are unable to get a suitable power source. Everyone can get clean and green wireless power. In future all the devices will relate to the power supply source wirelessly. In this paper we have presented the successful experimental attempts to transmit power wirelessly and future scope of wireless power transmission. We have tried to represent the future use of wireless power transmission in various areas where wired power transmission is impossible to supply implement.

As the speed requirements of imaging and communications systems increase, the latency requirements of digital circuits also become stringent. Due to such tight latency or timing requirements, large-stage pipelined circuits need to be redesigned to meet the low-latency requirements. Most modern imaging and communications systems rely on digital signal processing (DSP) that compute complex mathematical operations. The emergence of powerful and low-cost field programmable gate array (FPGA) devices with hundreds of arithmetic multipliers has enabled many such DSP hardware applications, traditionally implemented only as software solutions. The reciprocal square root algorithm is a popular technique for computing square roots, used widely in many software applications. This paper shows how this algorithm can be implemented efficiently on hard ware, and is suitable for lowlatency mathematically-intensive applications. Using a low-cost FPGA device, the algorithm takes up less than 1000 look up-tables (LUTs), which on an Artix XC7A200T device, translates to less than 1% of all the LUT resources in the chip.

Background: During last decades, an extraordinary improvement of bioinformatics has been observed that has prompted growth of a huge measure of biological data. The Bioinformatics and computational science aim to manage this huge volume of information. In the way biological data can be extracted, producing scientific knowledge, handling and mining huge information is at present a subject of incredible conspiracy and significance. Automation particularly in the information extraction step might be an essential technique to lessen the time important to finish an efficient research. However, the state of the art of automatically extricating information components from biological databases has not been all around portrayed.
Methods: Systematically PubMedInfo Crawler will identify potentially relevant articles and their details against different keywords. The included methodology met the following criteria: 1) Get keywords from user, send request to eutils.ncbi.nlm.nih.gov, fetch results from this server and then generate database to display output containing title and links of articles found against given keywords. 2) Transform these links into useful and structured form to get detailed information of each article: like PubMed id, title, abstract, journal name, authors’ name, publication date and country name to which authors belong. 3) Analyze the obtained details from different aspects that are discussed in detail in the methodology section.
Results: PubMedInfo Crawler (PMIC) has been developed to provide data extraction utilities for commonly used database PubMed. It is a simple web interface that enables input of query in the form of keyword and generates detailed useful information of each article against input keyword. Tool has been experimentally tested on different query keywords and has validated the results from PubMed. The overall accuracy of the crawler was found to be 96% for the number of articles against query terms. The tool is freely available.
Conclusion: This tools with help the public users to extract the data from Pubmed through an automatic way with less consumption of time. Furthermore it will help the researchers to accomplish their research in a better way with less effort.

Radiation induced soft errors are susceptible to most of the electronic products with the development of CMOS technology. A particle striking on any of the electronic products can produce soft errors that can be either single event upset or single event transient. There are various techniques such as FERST, BISER, TMR, DMR, DICE, SEC-DED, DEC-TED, EDAC, PARSHIELD, and STEM for soft error elimination. But these techniques do not provide self-checking capability, and has high area, output corruption. Soft Error and Timing error Tolerant Flip Flop (SETTOFF) is used to conquer these drawbacks. The self-checking is provided at the transition detection part. SETTOFF is designed for normal operation and fault operation. This has higher area overhead than BISER. So BISER by means of self-checking capability has been proposed to conquer the limitations by reducing the area. BISER by means of self-checking can yield better results with reduced area overhead, power and delay compared to SETTOFF architecture and BISER. The architecture is implemented using SPICE and simulation waveforms are obtained.

Most rural dwellers in developing countries do not have access to adequate and regular supply of energy and most of these estimated two billion people are poor with no sustainable means of livelihood and therefore rely on wood fuel for their cooking and heating needs. And due to lack of energy, including electricity, socio-economic development is either absent or at abysmally low level. To foster rural development and improved living conditions among this populace, there is need for a reliable, low cost and environmentally risk-free source of energy. This work designed, implemented and evaluated the performance of a dual axis solar tracking system (DATS) using LDR sensors, DC motors and microcontroller to make it capable of uninterruptible electricity supply for rural applications. Results of the experiment show that the proposed system is more cost-effective and produces 31.4% more energy than the single axis tracking system (SATS) and 67.9% more than the fixed PV panel system (FPPS). Owing to the unique design of the proposed tracking system, solar energy can be tracked and stored continuously so that there is adequate electricity for the consuming population at all times. Though tested on a rural community in Abia State, Nigeria, the proposed system can be adapted to rural communities anywhere in the world.

The anticipated research involve, Modeling and simulation of Renewable Energy Fed Brushless DC motor Drive using Improved DC-DC Converter for reducing vibration and noise. It consists of buck and boost converter, DC-link module. Compare with conventional converters, the designed system results in reduction of voltage tension across the switches, compact power switches, DC source reckoning and reduced inrush current. In this Enhanced converter DClink switching is achieved by abridged ripple voltage which results in improved quality of output power is obtained and it also reduces vibration, noise in the drive without affecting mechanical properties. Lessening in switch tot up makes the system more cost effective. A simulation of Buck-Boost converter is designed and its concert is analysed for various functioning factor conditions.

Line Start Permanent Magnet Synchronous Motors (LSPMSMs) combine the high efficiency of the permanent magnet synchronous motors (PMSM) with the ease of use, simplicity in design and high starting capability of the induction motors (IMs). Due to the rapidly growing usage of this relatively new motor, proposing a diagnostics method for broken rotor bar fault is necessity. In this paper, a diagnostics technique based on Artificial Neural Network (ANN) was developed to detect the broken bars fault in LSPMSM using Singular Value Decomposition (SVD) in order to extract distinguishing features from the stator phase current. This distinguishing attributes were proposed to be the inputs to the built neural network.