Issue 1, Volume 8,
January 2009
Title of the Paper: Direct
Solution of Compensated Radial Distribution Networks with Constant
Impedance/Current Loads
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Authors:
Antonino Augugliaro, Luigi Dusonchet, Salvatore Favuzza, Mariano G. Ippolito,
Eleonora Riva Sanseverino
Abstract: In this paper, a methodology to solve radial distribution networks,
with constant current and/or impedance loads as well as shunt capacitor banks,
is proposed. The techniques currently available to solve such systems are
based either on iterative methods or on the bus impedance matrix. In both
cases, the elaboration times are quite high since these are related, for
iterative methods, to the overall number of iterations, and, for those methods
based on the impedance matrix, to the inversion of the admittance matrix. The
method developed here is the extension of a technique that is valid to solve
networks made of impedances with one supply point. The methodology can also be
applied in the solution, with the backward/forward methodology, of meshed
systems having voltage-dependent loads and PV nodes. After having described
the two cited networks’ analysis methodologies, the new methodology is
developed and its implementation is described. The comparison of the
computational performances, in terms of CPU times, between the iterative
method, the method using the bus impedance matrix and the one developed in
this paper provide evidence regarding the efficiency of the latter in strongly
reducing the calculation times.
Keywords: Distribution
networks, Backward/forward method, Ladder networks
Title of the Paper: An
Inversion/non-Inversion Dynamic Optically Reconfigurable Gate Array VLSI
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Authors:
Minoru Watanabe, Mao Nakajima, Shinichi Kato
Abstract: Up to now, an optically differential reconfigurable gate array
taking a differential reconfiguration strategy and a dynamic optically
reconfigurable gate array taking a photodiode memory architecture have been
proposed. The differential reconfiguration strategy provides a higher
reconfiguration frequency, with no increase in laser power, than other
optically reconfigurable gate arrays, however the differential reconfiguration
strategy can not achieve a high-gate-count VLSI because of the area occupied
by the static configuration memory. On the other hand, the photodiode memory
architecture can achieve a high-gate-count VLSI, but its configuration is
slower than that of the optically differential reconfigurable gate array using
equivalent laser power. So, this paper presents a novel
inversion/non-inversion dynamic optically reconfigurable gate array VLSI that
combines both architectures. It thereby achieves both advantages of rapid
configuration and a high gate count. The experiments undertaken in this study
clarify the effectiveness of the inversion/non-inversion optical configuration
method.
Keywords: Field
programmable gate arrays, Optical reconfigurations, Holographic memories,
Optically reconfigurable gate arrays
Title of the Paper: Study on the
Applications of Extra-high Pressure Water Jet Technology
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Authors:
Yuefeng Fang, Xiaoyong Wang
Abstract: High-pressure Water Jet is a new technology that develops rapidly
these decades. By the development of upsizing intelligentizing and customizing
high-pressure water jet equipment, this technology has infiltrated into many
application areas. The paper mainly discusses the mechanism of de-rusting by
ultra-high pressure (short for u.h.p.)pure water as high as 200 to 250Mpa. It
adopts u.h.p rotating waterjet, automatic wall-climbing and rust dregs vac
sorbing and recycling. Mechanism of water-jtetting de-rusting is to scour and
strip the rusty scale of the converted steel surface by normal hitting power
and edge angle of waterjet and twisting force of rotating. The testing proves
the mechanism equation.
Keywords: U.H.P Waterjet,
De-rusting, Mechanism Testing
Title of the Paper: Research and
Design of Meter Reading System Based on ZigBee Wireless Sensor Network
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Authors:
Dechao Sun, Shaohua Zheng
Abstract: With the rapid development of wireless technologies, it is possible
for Chinese automatic meter reading system (AMRS) to be equipped with wireless
sensor networks due to their low-cost, simplicity and mobility. In the current
study, we compared the advantages of ZigBee with other two similar wireless
networking protocols, Wi-Fi and Bluetooth, and proposed a wireless solution
for AMRS based on ZigBee technology. As an explorative application of ZigBee
technology in AMRS, The design reduces the system cost and power consumption
and improves the system’s flexibility and practicality.
Keywords: Wireless meter
reading, ZigBee, IEEE802.15.4, JN5121, Profile
Title of the Paper: Based on
Embedded Database Greenhouse Temperature and Humidity Intelligent Control
System
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Authors:
Sun Rong-Gao, Wan Zhong, Sun De-Chao
Abstract: The article based on embedded database of greenhouse temperature and
humidity control system intelligent. Put forward by embedded database system
set up in an ideal environment for data greenhouse temperature and humidity
control, greenhouse crops in the process of growth under control. To address
the growth of greenhouse crops in the process of temperature and humidity
controlled environment is not ideal at the same time improve the efficiency of
control and cost-effective system. The article focuses on the system design,
the structure of the control system, hardware software make up and the system
control strategy. At the same time outlines some research directions. This
control system has a simple hardware structure, reliable data records,
installation, maintenance and use of convenience features. Can used in kinds
of temperature and humidity automatic control of environment of type.
Keywords: Embedded
database, Temperature and Humidity, Control, data filtering, Greenhouse,
Microcontrollers
Title of the Paper: Research of
the Chinese CAPTCHA System Based on AJAX
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Authors:
Dong Chen
Abstract: In this paper, we firstly introduce that CAPTCHA technology
development and the various type of reading CAPTCHA, sound CAPTCHA, graph
CAPTCHA at present. The second, we build one kind of the Chinese CAPTCHA
model. The third, a new Chinese CAPTCHA system based on AJAX is proposed,
which proceed to generate character characteristic based random problem and
answer. On its performance, we show that the advantages of the Chinese CAPTCHA
system due to its improved security and the reliability of the technology
using it.
Keywords: CAPTCHA, AJAX,
system, network, attacker, random, XML
Title of the Paper: Design of MMIC
Based on Mean Selection Methed and Research the Model of MMIC Non-Dissipative
MESFET
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Authors:
Bolin Ke, Chunhua Li, Yang Ai-Min
Abstract: Multi-object mean selection, an efficient method applicable to
design mean of monolithic microwave integrated circuits (MMIC), is presented
in this article. Based on theories of Monte Carlo analysis and yield
histogram, this method first extracts multi-object mean points from yield
histograms, then picks out optimal mean upon them by yield comparison. In the
implementation of this method , a combination of interpolation sampling,
parametric sampling and sample recognition methods is developed to improve
Monte Carlo analysis, which keeps accuracy and attains more efficiency. With
this advanced numeric physical models, the method of multi-object mean
selection becomes far more accurate and reliable for MMIC designing. Analysis
on the principle and characteristic of Non-dissipative MESFET mixer circuit
has been discussed in detail in this paper. During research of CAD of this
type of mixer,the technique of expanding the MESFET model has been offered. On
the basis above,the 12.4~18GHz non-dissipative MESFET mixer have been designed
. The mixer performs -3dB of conversion gain.
Keywords: CAD, MESFET
mixer, MMIC, Transfer characteristics, Local oscillation, Non-dissipative
Title of the Paper: Dynamic
Application of Slicing Technique in Grid Calling and Network Resources
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Authors:
Lixia Wang, Aimin Yang, Yaohui Li, Liting Gao, Tieying Liu
Abstract: The grid links all resources in different structures widespread
geographically into one logical system via internet, characterized with
complexity of network structure, dynamism of network resources and autonomy of
each LAN. The high-efficient management of grid resources and high-efficient
scheduling of tasks are the important contents in today’s net grid research.
Slices technology is the present quite popular popular technology, the
application domain is widespread. The grid technology and the slice technology
fuse in together, may create the more reasonable task scheduling and the
scheduling of resources. In this article we divide the tasks into some small
tasks assigned with scheduling priorities for each level, and then slice all
resources in network into some time slices assigned with resource priorities
according to trust mechanism. It promotes the effectiveness and
high-efficiency by arranging task scheduling and resource scheduling in
priority.
Keywords: Grid computing,
Slicing Technique, Slice Min—min algorithm, Trust mechanism, Load Balancing,
Distributional dispatch, Toughness, Correspondence detention
Title of the Paper: The Optimal
Design and Simulation of Helical Spring based on Particle Swarm Algorithm and
Matlab
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Authors:
Xiao Qimin, Liu Liwei, Xiao Qili
Abstract: Optimal problem is often met in engineering practice. The method to
solve complex optimal problem is always studied by people. Springs are
important mechanical members which are often used in machines to exert force,
to provide flexibility, and to store or absorb energy. Helical spring is the
most popular type of springs. The method of helical spring optimization is a
typical one which can be used to solving other mechanical optimal design
problem. Particle Swarm Optimization algorithm is a good method in solving
optimal problem. MATLAB is a high-performance language for technical computing
and is an easy tool for us to simulate the optimization. In this paper, we
mainly introduce the optimization of helical spring based on particle swarm
algorithms and simulation in MATLAB. Directed by the theory of Particle Swarm
Optimization algorithm, with the minimum weight of helical spring as objective
function, with d, D2 and n as design variables, with shear stress, maximum
axial deflection, critical frequency, bucking, fatigue strength, coils not
touch, space and dimension as constraint conditions, the complex helical
spring optimal design mathematics model with three design variables and
fourteen inequality constraints conditions is established. When the model is
simulated in MATLAB the minimal optimal value of variables and the minimal
weight of helical spring can be obtained. Simulating Result shows that
Particle Swarm Optimization is practical in solving complicated optimal design
problems and effectively on avoiding constraint of solution. The fundamental
idea, the method of establishing mathematic model, the simulation process in
MATLAB of helical spring can be used for reference to other similar mechanical
optimal design.
Keywords: Particle Swarm
Optimization (PSO), fitness value, local best value, global best value,
helical spring, optimal design, mathematic model , objective function, design
variables, constraints condition, shear stress, deflection, critical
frequency, bucking, f
Title of the Paper: SAR Image
Localization and Target Recognition Research Based on the Azimuth Circle
Adjustment
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Authors:
GuangYang, Xiaojuan Wang, Dejun Li, BaiZhang, Kun Gao
Abstract: According to the work mechanism of space synthetic aperture radar
(SAR), this text introduced the localization algorithms of SAR image and the
method of system error adjustment. On the basis of the concept of the azimuth
circle and the combination of the north direction coordinate system of
geography, carries on the adjustment to the localization data, so increased
the SAR image localization accuracy at large scale, combines the simulated
data and the image of Radarsat satellite, validate the localization algorithm
and the adjustment method. The results had indicated that this algorithm might
enable the localization accuracy of Radarsat image to achieve 400-600m, if the
establishment of earth model might more accurate, the ground station could
provide the more precise orbital data, the localization accuracy may further
enhance. After the studying localization, summarizes to the research
evolvement and the development uptrend of the goal pretreatment, the automatic
detection and the recognition aspect in the SAR imagery, table the proposal
for the future SAR image’s recognition and the localization research.
Keywords: ITSM, Process
Model, Framework, ITIL, UML
Title of the Paper: Monitoring of the
Pressure Inside the Cylinder for an Internal-Combustion Engine
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Authors:
Sorin Ratiu, Gabriel Nicolae Popa, Vasile Alexa
Abstract: This work presents the achievement of a monitoring, recording,
processing and interpretation concept, at laboratory scale, of the pressure
inside the combustion chamber for a spark-ignition engine, based on electronic
equipment, which measures the values of 17 parameters that describe the
operation of an internal-combustion engine. The measured pressure depends on
the crankshaft’s position. Is used a pressure transducer with strain-gauge
socket, and measurement of the crankshaft’s position with a speed transducer
with variable reluctance. From experimental data, on one hand, can be analyzed
the pressure modification in the combustion chamber depending on the
crankshaft’s position, and on the other hand, the maximum pressure
modification in the cylinder depending on the speed.
Keywords:
Internal-combustion engine, Sensors, Cylinder, Pressure, Speed
Title of the Paper: Assessment of Power
Quality for Line Frequency Coreless Induction Furnaces
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Authors:
Angela Iagar, Gabriel Nicolae Popa, Corina Maria Dinis
Abstract: This paper presents a study about power quality problems generated
by line frequency coreless induction furnaces. We analyzed a furnace with 12.5
t capacity of cast-iron. The measurements have been made in the primary of the
furnace transformer, on the MV line, using the CA8334 three-phase power
quality analyser. Experimental results emphasized the presence of harmonics
and interharmonics in the phase voltages and harmonics in the currents
absorbed from the MV network. Further to harmonic analysis of the measured
signals, we have been proposed some optimization methods for operation of
analyzed furnace, in such way to comply with the European norms of
Electromagnetic Compatibility (EMC).
Keywords: Power quality,
Harmonics, Interharmonics, Induction furnace
Title of the Paper: Quadratic Fluency
DA Functions as Non-Uniform Sampling Functions for Interpolating
Sampled-Values
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Authors:
Kazuki Katagishi, Kenichi Ikeda, Mitsuteru Nakamura, Kazuo Toraichi, Yasuhiro
Ohmiya, Hitomi Murakami
Abstract: Interpolation for sampled-values with non-uniform sampling points is
required for various cases of signal processing. In such a case, sampling
functions are useful to interpolate sampled-values and then to generate
signals as a linear combination of the sampling basis weighted by a sequence
of the sampled-values. This paper proposes sampling functions for non-uniform
sampling points, each of which is composed with piecewise polynomials of
degree 2. We name the sampling functions the fluency DA functions of degree 2.
The fluency DA functions generate smooth and undulate signals from a sequence
of sampled-values.
Keywords: Fluency
information theory, Fluency DA functions, Interpolation, Non-uniform sampling
functions, Piecewise polynomials
Title of the Paper: Transformer Fault
Diagnosis Based on Reasoning Integration of Rough Set and Fuzzy Set and
Bayesian Optimal Classifier
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Authors:
Hongsheng Su, Haiying Dong
Abstract: In accordance with intelligent complementary strategies, a new
transformer fault diagnosis method is proposed based on rough set (RS) and
fuzzy set (FS) and Bayesian optimal classifier in this paper. Through RS
reduction, the diagnostic decision table is greatly simplified and fault
symptoms information is compressed, dramatically, and the minimal decision
rules can be obtained. In the light of the minimal decision rules, the
complexity of Bayesian reasoning and difficulties of fault symptom acquisition
are dramatically decreased. Moreover, probability reasoning may be realized
applying Bayesian optimal classifier, it can be used to describe the
characteristics of fault information and investigate the fault reasons of
transformer. In the end, a practical application in transformer fault
diagnosis indicates that the proposed method is very effective and intelligent
and ubiquitous.
Keywords: Rough set, Fuzzy
set, Bayesian optimal classifier, Fault diagnosis, Information entropy,
Intelligent complementary, Transformer
Title of the Paper: The Star-Routing
Algorithm Based on Manhattan-Diagonal Model for Three Layers Channel Routing
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Authors:
Jiann-Chyi Rau, Po-Han Wu, Chia-Jung Liu, Yi-Chen Lin
Abstract: In this paper, we employ gridded model for channel routing and place
the terminals which are horizontally aligned. We have developed a two-layer
channel router that can eliminate the constraints due to overlap. The proposed
approach is suitable for cell/IP-based channel-less circuit with a few
channels. Our developed tool can route the nets in nearly linear time
achieving to the advantage of time to market, and lead to the area overhead of
6.34% increase in average. The area overhead results from the space insertion,
and we also have shown that the proposed algorithm can achieve 100% routing on
most ISCAS’85 benchmarks. In addition, the number of channel tracks can be
minimized by our algorithm. We proposed the star-routing algorithm for three
layers channel routing using Manhattan-Diagonal Model to solve the channel
routing problem. We drew up the smaller grid-model, and in order to avoid
violating the DRC, so the algorithm has a restriction for the third
metal-layer in routing step. We don’t need to increasing extra spaces and
moving any pins in order to finish the routing completely. The foregoing is
good for hard blocks to finish the routing easily, and it does not replace the
location of hard blocks because of routing incompletely. Therefore, the height
of the entire routing channel can reduce a lot.
Keywords: Channel routing,
Manhattan-Diagonal Model, Electronic Design Automation (EDA)
Title of the Paper: New Approach
Regarding the Electroerosion Estimation of the Circuit Breakers Contacts
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Authors:
Catalin Pancu, Adrian Baraboi, Maricel Adam
Abstract: In the estimation of the circuit breakers technical state, it is
very important to knows its contacts electroerosion. The electroerosion
depends on the following main parameters: switching number realised, currents
values that have been switched, existence time of electric arc at each
switching. Electroerosion estimation of the contacts realised in operation
leads to an overestimation inducing a supplementary maintenance. Thus it is
necessary an evaluation of short-circuit currents in the mounting place of
circuit breakers from electrical installations and a reconsideration of
switching number at short-circuit of its. In this paper is shown an
experimental model of an embedded intelligent system for the technical state
evaluation of the switchgears contacts, from electroerosion point of view.
This approach has the advantage that the architecture can be used, also, for
the monitoring of the some cinematic parameters for the operating mechanism,
like as: closing/opening velocity, closing/opening time, the stored energy in
the operating mechanism and others.
Keywords: Circuit breaker,
Contacts electroerosion, Contacts wearing, Intelligent system, Microcontroller
Title of the Paper: Modification of the
Cockcroft-Walton Charge Pump by using Switched Capacitors Technique for
Improved Performance under Capacitive Loads
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Authors:
Davor Vinko, Tomislav Svedek, Tomislav Matic
Abstract: This paper presents a modified Cockcroft-Walton charge pump designed
for driving capacitive or low current resistive loads. The proposed
modification by using switched capacitors technique shows great improvement in
output voltage levels that it achieves, and in number of capacitors needed for
reaching a certain voltage level. Also, it requires no additional clocking
scheme besides the present single phase AC signal. The proposed Switched
Cockcroft-Walton (SCW) charge pump was simulated and compared with the CW
charge pump.
Keywords: Charge pump,
Driving capacitive loads, Heap pump, High-voltage generation, Switched
capacitors, Voltage multiplier
Issue 2, Volume 8,
February 2009
Title of the Paper: Automated Meter
Reading System for Heat Costs Allocation
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Authors:
Ioan Lie, Virgil Tiponut, Ivan Bogdanov, Sabin Ionel, Catalin Daniel Caleanu
Abstract: The paper presents the design and the implementation of an automated
meter reading system for heat costs allocation. The system was developed on
three levels: the data acquisition level – where data are recorded from field
with costs allocators installed on the radiators; a data concentration level –
were data registered by allocators are read at a predetermined time interval
with data concentration units and a data processing level – for uploading
information in a PC hosted data base for various works afterwards. For each
level was defined the hardware requirements and the software specifications
including the communications modules, the meter and the user interfaces. A PWM
data encoding was proposed as an alternative encoding for wireless
communication through RF between data acquisition and concentration levels.
The system uses RF for data transmission but also includes a pair of RFID
modules facilitating remote programming and diagnostic procedures. In order to
fulfill the low power requirements the dedicated modules costs allocator and
data collection unit were implemented around MSP430 low power
microcontrollers.
Keywords: Costs allocator,
Sensor network, Temperature measuring, Data concentrator, Radio communication,
Automatic meter reading, RFID, Low power
Title of the Paper: The Analysis of
Circuit Breakers Kinematics Characteristics using the Artificial Neural
Networks
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Authors:
Maricel Adam, Adrian Baraboi, Catalin Pancu, Sorin Pispiris
Abstract: The paper presents the required parameters in the evaluation of the
technical state for the High Voltage (HV) circuit breakers. It details some
aspects regarding the influence of the kinematics characteristics to the
circuit breakers performances. Also, it presents a possibility to use the
artificial neural networks (ANN) in the analysis of the circuit breakers
kinematics characteristics, in order to diagnostic their technical state. The
required database necessary for learning of ANN has determined through the
modelling of the mechanical system of movement transmission, using the systems
of electrical nature, with RLC elements.
Keywords: Circuit breaker,
Kinematics characteristics, Modelling and simulation, Monitoring, Diagnostic,
Artificial neural network
Title of the Paper: Steady State
Modelling of Induction Motor Operating with Unbalanced Supply System
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Authors:
Kanwarjit Singh Sandhu, Vineet Chaudhary
Abstract: Three phase supply system is found to be quite balanced in both
magnitude and displacement at the generation levels but it is not so at
distribution end. Voltage unbalance which is a common and global phenomenon is
found to be very effective in deteriorating the performance of electrical
apparatus at user end. Such environment badly affects the performance of
induction motors, an important class of electric machines which is widely used
in industrial. Present paper is an attempt to tackle such operations with
specific recommendations & proposals. Symmetrical component approach is
adopted to estimate the performance of a three-phase induction motor operating
with unbalanced supply system. Further MATLAB/SIMULINK & PSIM environments
have been used simultaneously for simulation purpose. A new approach is
proposed to rerate the motor operating with voltage unbalance.
Keywords: Abnormal
operation, Three Phase Induction Motors, Rerating, Steady state Analysis,
Unbalanced Supply
Title of the Paper: Improved Design of
Three-Level NPC Inverters in Comparison to Two-Level Inverters
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Authors:
Ahmad Radan, Hengameh Kojooyan Jafari
Abstract: As voltage source 3-level NPC inverters are suitable for AC drives
in average voltage and FACT applications in distribution systems, this report
introduces optimized design of 3-level NPC inverter by decreasing inverter
losses and costs. At first optimization parameters and application functions
of losses are introduced[1], then by using MATLAM6.5 program and IGBT, diodes,
switching frequency and load current typical input parameters [1] are
considered then by SPWM switching algorithm in program, optimized RGon , RGoff
and gate voltage for 3-level NPC inverters are calculated for minimizing
switching and conduction losses of inverter among all amounts of calculated
RGon , RGoff and gate voltage in comparison to optimized design of 2-level
inverters[1]. Then results of NPC optimization are applied for simulation of
improved NPC, using SVM switching algorithm as the best method of switching
and results are presented.
Keywords: Design, IGBT
inverter, NPC, SPWM, SVM, loss model, optimization
Title of the Paper: Simulation of
Doubly-fed Machine with Improved Wind Turbine
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Authors:
Hengameh Kojooyan Jafari
Abstract: Most of wind turbines use induction generators that are very
reliable with low costs [2], but when it is straightly connected to the grid,
maximum power is not accessible [1] and only a few change of speed between
maximum speed and synchronous speed is possible [1].
In this report, a doubly-fed induction generator with winding-rotor
configuration, external rotor resistance and external rotor source that has a
variable phase and amplitude is used. This doubly-fed induction generator has
larger range of change of speed than induction generator and its application
in wind systems is very common. Also in doubly-fed machine, both active and
reactive power control is possible [3].
In this report, a doubly-fed induction machine with an improved wind turbine
has been simulated, then with selecting suitable control parameters by open
loop controlling, maximum turbine active power at an adapted speed is exerted
to the grid and the results is presented.
Keywords: Doubly-fed
machine, Wind Turbine, Gearbox ratio, Low speed shaft, High speed shaft.
Title of the Paper: Online State
Diagnosis of Transformer Windings based on Time-frequency Analysis
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Authors:
Yuying Shao, Zhushi Rao, Zhijian Jin
Abstract: The power transformers are the key equipments in the power system.
To keep the stable operation of the transformers, it’s necessary to get their
state information on a real-time basis. Therefore, the efficient online
monitoring system is developed which obtain the state of the transformers by
the accelerometers attached on the tank. The locations of these accelerometers
can be determined by the method of varying current with constant frequency.
The vibration intensity change is used to initially detect the windings' state
by online monitoring the vibration signal of the shocks. Then the
time-frequency analysis further processes these signals in order to detect the
fault information contained. The short-circuit experiments have been done on
the large power transformer of 50000KVA, which finds that the time-frequency
analysis can be used to more precisely detect the fault characteristics of
windings. Compared with traditional off line short circuit reactance method,
the time-frequency analysis is more effective.
Keywords: Transformer
winding, time-frequency analysis, Vibration intensity,Short-circuit reactance,
Condition monitoring
Title of the Paper: The Circuit Design
of Current-Mode Image Sensor Embedded Smooth Spatial Filter with Flash A/D
Converter
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Authors:
Chia-Chun Tsai, Huang-Chi Chou, Trong-Yen Lee
Abstract: The paper presents a current-mode CMOS image sensor embedded smooth
spatial filter algorithm with a flash analog-to-digital (A/D) converter. The
sensor includes a 66?66 pixel array with an on-chip 6-bit A/D converter that
can identify the output value of pixels in gray level resolution. The last row
of pixel cells (1?66) based on the double sampling is used for reducing fixed
pattern noise (FPN). Processing circuits are dedicated for the spatial filter
algorithm and support reusability to increase the image processing speed and
to reduce the design complexity and chip area. The sensor chip has been
designed and implemented in TSMC 0.35?m 2P4M CMOS mixed-mode process.
Experimental results show that each pixel occupies a area of 15.8?m?10.6?m
with a fill factor of 37.2%. The power consumption is 35.15mW when the sensor
operates at 175 frames/second.
Keywords: Image senser,
smooth spatial filter, Flash A/D converter, pixel cell, CMOS process
Title of the Paper: An Adaptive Scheme
for Distributed Dynamic Security Assessment of Large Scale Power Systems
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Authors:
Xing-Zhi Wang, Zheng Yan, Li Li
Abstract: The requirements for significant computational resources imposed by
dynamic security assessment applications have led to an increasing interest in
the use of parallel and distributed computing technologies. This paper
presents an adaptive scheme that involves user-friendly flat application
program interfaces for scripting and an object-oriented programming
environment for distributed dynamic security assessment implementation.
Functional parallelism and data parallelism are supported by each of the
message passing interface model and TCP/IP model. Adaptive stochastic-based
objectives and conservative parameter prediction techniques are used to
produce more efficient data parallelism. Tests for a 39-bus network and a
3872-bus network are reported, and the results of these experiments
demonstrate that the proposed scheme is able to execute the distributed
simulations on either stand-alone personal computers, cluster systems, or a
computational grid infrastructure and provide efficient parallelism for the
given environment.
Keywords: Adaptive
systems, graph partitioning, parallel processing, parameter estimation, power
system
Title of the Paper: Forward
Transmission over a Multipath Faded Channel in a DS CDMA System
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Authors:
Abdel-Rahman Al-Qawasmi, Omar Al-Ayasrah, Ayman Al-Lawama
Abstract: The pseudorandom spreading sequence in the forward transmission in
the IS -95 system is assigned only to individual base stations . To separate
users, the system assigns orthogonal (Hadamard) sequences to each of them. In
this paper, a different scheme for the forward transmission is considered. In
this scheme pseudorandom sequences are u sed, instead of employing orthogonal
spreading sequence for individual users. The effect of fade amplitudes, phase
shifts, time -mismatching and AWGN on the detection process of Gold Sequence
Spread Spectrum Signal (GSSSS) is considered.
Keywords: Gold sequence,
Rake receiver, Time-mismatching, QPSK-GS SS receiver
Title of the Paper: Joint Optimization
Algorithm for Network Reconfiguration and Reactive Power Control of Wind Farm
in Distribution System
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Authors:
Jingjing Zhao, Xin Li, Jiping Lu, Congli Zhang
Abstract: In recent years, the number of small size wind farms used as DG
sources located within the distribution system are rapidly increasing. Wind
farm made up with doubly fed induction generators (DFIG) is proposed in this
paper as the continuous reactive power source to support system voltage
control due to the reactive power control capability of DFIG. In the
distribution system, considering network reconfiguration and wind farm
reactive power control are both used to improve power profile and they have an
inherent coupling relationship, in this paper, a joint optimization algorithm
of combining reactive power control of wind farm and network reconfiguration
is proposed. In the proposed joint optimization algorithm, an improved hybrid
particle swarm optimization with wavelet mutation algorithm (HPSOWM) is
developed for voltage profile improvement which utilized reactive power output
of wind farm as the control variable. In each particle updating instance at
each iteration of reactive power output optimization algorithm, a binary
particle swarm optimization algorithm (BPSO) is utilized to find the optimal
network structure. Finally, classical 16-node feeder is used as a test case to
evaluate the algorithm. The experimental result demonstrates the correctness
of the algorithm.
Keywords: Wind farm, DFIG
wind turbine, reactive power control, network reconfiguration, particle swarm
optimization
Title of the Paper: Semiconductor
Nanointerface Eigenstate-Photoevolution
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Authors:
E. A. Anagnostakis
Abstract: The dynamics of photonic evolution for the eigenstate of a generic
semiconductor-nanointerface is studied in terms of its two-dimensional
electron gas (2DEG) fundamental-sublevel eigenenergy’s correlation with
respective 2DEG areal density, versus instantaneous cumulative photonic
intake. Application of this treatment to the experimental photoresponse of
typical modulation – doped optoelectronic nanodevices leads to a realistic
tracing of the nanostructure pertinent photodynamics.
Keywords: Nanotechnology,
optoelectronics, functional eigenstate, nanodevice, photodynamics,
two-dimensional electron gas
Title of the Paper: High Speed Gate
Level Synchronous Full Adder Designs
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Authors:
Padmanabhan Balasubramanian, Nikos E. Mastorakis
Abstract: Addition forms the basis of digital computer systems. Three novel
gate level full adder designs, based on the elements of a standard cell
library are presented in this work: one design involving XNOR and multiplexer
gates (XNM), another design utilizing XNOR, AND, Inverter, multiplexer and
complex gates (XNAIMC) and the third design incorporating XOR, AND and complex
gates (XAC). Comparisons have been performed with many other existing gate
level full adder realizations. Based on extensive simulations with a 32-bit
carry-ripple adder implementation; targeting all the three process, voltage
and temperature (PVT) corners of the high speed (low Vt) 65nm
STMicroelectronics CMOS process, it was found that the XAC based full adder is
found to be delay efficient compared to all its gate level counterparts, even
in comparison with the full adder cell available in the library. The XNM based
full adder is found to be area efficient, while the XNAIMC based full adder
offers a slight compromise with respect to speed and area over the other two
proposed adders.
Keywords: Combinational
logic, Full adder, High performance, Standard cells, and Deep submicron design
Issue 3, Volume 8,
March 2009
Title of the Paper: Toward in Vivo
Digital Synchronous Sequential Circuits
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Authors:
Miha Moskon, Monika Ciglic, Nikolaj Zimic, Miha Mraz
Abstract: We present the model of a first digital synchronous sequential
circuit, i.e. 1-bit synchronous counter, which is about to be realized within
the living cell. Mathematical model was constructed upon gene expression based
logic with ordinary differential equations (ODEs), particularly Hill
equations. The behaviour of the counter was simulated in Matlab/Simulink
environment. With the promising simulation results presented in the paper
physical realization of the circuit described within the living cell can be
initiated. Introduction of synchronization with a special signal, i.e. clock
signal, brings many benefits to the field. Realization of such circuit would
therefore present an important step toward the construction of complex
biological information processing capable systems.
Keywords: Synthetic
biology, Protein-based computing, Sequential logic, Synchronization, Ordinary
differential equations, Biological modelling, Circuits, Master-Slave flip-flop
Title of the Paper: Responsivity
Robustness of Radioactivity-Irradiated Nanosensors
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Authors:
E. A. Anagnostakis
Abstract: The responsivity robustness of representative
photodetector-nanointerfaces with respect to the extent to which they exhibit
radiation hardness and the degree of functionally tolerable
radioactivity-induced responsivity de-emphasis, against increasing cumulative
radioactivity-dose, is notionally considered and modelled. Systematic
experimental findings concerning commercial p-i-n photodetectors being exposed
to regulated successive α-particle bombardments appear in compliance with the
analysis and reveal noteworthy trends of radiation-effected
optoelectronic-yield alteration.
Keywords: Responsivity
Robustness, Nanosensors, Radioactivity Irradiation Radiation-Hardness,
Optoelectronic Reliability, Photodetectors, Photoresponsive Nanointerfaces,
Quantum Efficiency & Detection Yield.
Title of the Paper: Computer-Aided
Design, Analysis and Optimization of HMIC SOP Broadband Balanced Amplifier
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Authors:
Said H. Ibrahim
Abstract: The purpose of this paper is to present a complete design and
analysis of new HMIC 3.5-4.5 GHz broadband balanced amplifier modules using
microstrip technology. Two different modules are designed and analyzed. Each
module is implemented in a single substrate. The first module used Lange
couplers as power splitters and combiners while the second used branch
couplers. The components of the modules are designed using full-scale computer
simulation program, performed by the author and named as MSDES, which takes
fully into account all the discontinuities included in the microstrip lines;
while the modules are analyzed and optimized using APLAC V7.61 software. A
short and efficient CAD procedure for the broadband amplifier design is
introduced. The first step is to design an initial narrowband high-gain
microstrip amplifier at a center frequency equal to 4 GHz. The second step is
to optimize the initial lengths and widths of the input and output microstrip-matching
circuits to get the broadband amplifier over the range 3.5-4.5 GHz. The
analyses of both narrow and broadband amplifiers are introduced in addition to
the complete analysis of the designed 3.5-4.5 broadband balanced amplifier
modules. The analysis of the designed balanced amplifier modules shows better
efficiency and good performance. The complete AC schematic diagrams of the
designed balanced amplifier modules are presented. These modules can be used
in many applications including sensors, pulse Doppler communications, airborne
radars, traffic control radars and satellite communications.
Keywords: Computer-Aided
Design and Analysis, Microstrip Technology, Microwave Devices and Systems
Issue 4, Volume 8,
April 2009
Title of the Paper: A Variable Voltage
MPPT Control Method for Photovoltaic Generation System
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Authors:
Liu Liqun, Wang Zhixin
Abstract: To increase the output efficiency of a photovoltaic (PV) generation
system it is important to have an efficient maximum power point tracking (MPPT)
technique. This paper describes the analysis, design and implementation of an
efficient tracking method for a stand-alone PV generation system, which
automatically adjusts the reference of output voltage to track the maximum
power point (MPP) by using the expiatory program. Compared with the
conventional constant voltage (CV) method, the proposed approach can
effectively improve the tracking speed and accuracy simultaneously.
Furthermore, an improved control system is designed for the
pulse-width-modulation (PWM) inverter to achieve the objective of MPPT.
Theoretical analysis and principle of proposed method are presented and
simulation results are given to verify the validity of control method.
Keywords: Maximum power
point tracking (MPPT), Variable voltage, Pulse-width-modulation (PWM),
Photovoltaic generation system, Solar energy
Title of the Paper: An Equilibrium
Model for the Joint FTR/FGR Auction Market
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Authors:
Jianlin Yang, Zheng Yan, Wen Jiang
Abstract: As an important instrument to hedge against the risk of congestion
charges, transmission right has been successfully implemented in practice.
There are two basic transmission rights, point-to-point financial transmission
right (FTR) and flow-based right (FGR). The equilibrium model for the joint
FTR/FGR auction market is established in this paper. Every TR (transmission
right) bidder can bid for any portfolio of FTRs and FGRs in this model, and
the contingency constraints are also involved in the simultaneous feasible
test (SFT). Besides, the analysis for the established model is also presented.
The resulting equilibrium model is formulated in terms of a mixed linear
complementarity problem, which is converted into the computation of a convex
quadratic programming in this paper. The standard PJM-5-bus system is used to
illustrate the proposed equilibrium model.
Keywords: FTR obligation,
FTR option, FGR, simultaneous feasible test, convex quadratic programming
Title of the Paper: Electrical
Equivalent Circuit of Ceramic Insulators with RTV Silicone Rubber Coating and
Computer Simulation of Leakage Currents
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Authors:
Suwarno, Fari Pratomosiwi
Abstract: During operation, high voltage insulators may severe a certain
degree of pollution which may reduce their performances. RTV silicone rubber
coating was proposed to improve the performances of outdoor ceramic insulators
especially in highly polluted areas. This paper reports experimental results
on the leakage current (LC) on RTV silicone rubber-coated ceramic insulators.
The samples used were 20 kV post-pin ceramic insulators. The samples were
coated by RTV silicone rubber from Dow Corning. There were 2 kinds of samples.
The first one is clean and the second one is kaolin-salt polluted. The sample
was put in a climate chamber under certain condition of fog. AC voltage of 50
Hz was applied to the sample and the leakage current flowed on the insulator
surface was measured by measuring the voltage across a series resistance using
a Digital Oscilloscope with sampling rate of 1 GS/s. The digital data was
transferred to a personal computer trough a GPIB for further analysis. The
experimental results showed that LC waveforms of RTV-coated insulators in
general are distorted from sinusoidal applied voltage. The LC waveforms are
symmetrical for positive and negative half cycles and no flashover was
observed for applied voltage up to 60 kV. The THD as well as magnitude of the
LC increased with applied voltage for both clean and kaolin-salt polluted
samples. From the experimental results, electrical equivalent circuit models
are proposed. Using the proposed model computer simulation of leakage current
waveforms was done using APT/EMTP under various conditions and applied
voltages. The simulation was done by choosing appropriate values of
capacitances, non linearity and arc models. The simulated LC waveforms were
compared to those obtained from experiment. The similarity of the LC waveforms
was determined by comparing the LC magnitude, THD, dominant harmonic
components and symmetry. The results indicated that simulated leakage current
waveforms were similar to those obtained from experiment. These revealed the
validity of the proposed model.
Keywords: Ceramic
insulator, RTV coating, equivalent circuit, leakage current, harmonics,
computer simulation
Title of the Paper: CMOS Implementation
of an Artificial Neuron Training on Logical Threshold Functions
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Authors:
V. Varshavsky, V. Marakhovsky, H. Saito
Abstract: This paper offers a new methodology for designing in CMOS technology
analog-digital artificial neurons training on arbitrary logical threshold
functions of some number of variables. The problems of functional ability,
implementability restrictions, noise stability, and refreshment of the learned
state are formulated and solved. Some functional problems in experiments on
teaching logical functions to an artificial neuron are considered.
Recommendations are given on selecting testing functions and generating
teaching sequences. All results in the paper are obtained using SPICE
simulation. For simulation experiments with analog/digital CMOS circuits,
transistor models MOSIS BSIM3v3.1, 0.8μm, level 7 are used.
Keywords: Artificial
neuron, CMOS implementation, learnable synapse, excitatory and inhibitory
inputs, learning process, learning sequence, refreshment process, test
function, threshold logical element, threshold logical function, Horner's
scheme, Fibonacci sequence
Issue 5, Volume 8,
May 2009
Title of the Paper: Design and Analysis
of SOP-HMIC Transceiver with Integrated T/R Switch
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Authors:
Said H. Ibrahim, El-Sayed A. El-Badawy
Abstract: The demand for higher performance systems that are smaller and have
the potential to be more cost effective has lead the hardware designers to
adopt integration of many components and modules in a package (SOP) or on a
chip (SOC). Two compact SOP (single-substrate) SO-HMIC transceivers with
integrated T/R switch modules for high-resolution sensor application have been
demonstrated. These modules contain singly-balanced diode mixer; using either
rate-race or Lange coupler; lowpass filter, 7-dB power splitter using branch
coupler and T/R switch. A new and efficient methodology is investigated for
the design of microstrip T/R switch. The components of the modules are
designed using the full-scale computer simulation program performed with the
authors, while they are analyzed and optimized using the Aplac V7.61 software.
The analysis of the designed transceiver modules is introduced which reflects
a good performance and achieves a higher efficiency.
Keywords: Computational
Microstrip Circuit Design, Microwave Circuits and systems, Computer Aided
Design (CAD)
Title of the Paper: A Novel
Soft-Switching Converter for Switched Reluctance Motor Drives
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Authors:
Kuei-Hsiang Chao
Abstract: A high efficiency converter for switched reluctance motor (SRM)
drive is developed in this paper. In the proposed converter, the power
semiconductor device with shorter switching time is employed to implement its
high-speed PWM switches. And the soft-switching control is employed for
further reducing their switching losses. To achieve this, an auxiliary
resonant circuit is added to the PWM switch, and its zero-voltage-transition (ZVT)
soft switching is obtained by applying suitable switching signals to the main
and auxiliary switches. No extra voltage and/or current sensors are required.
Having derived the governing circuit equations, a design procedure is proposed
to systematically find the constituted components of the auxiliary branch. As
to the low-speed commutation switches, they are realized using the power
device having low on-state voltage. Owing to the ability of making PWM
switching control, the SRM motor drive with the proposed converter possesses
good driving performance. The performance of the designed converter is
demonstrated by some simulation and experimental results. An approach for
measuring the energy conversion efficiency of a SRM drive is also proposed.
Keywords: Switched
reluctance motor (SRM), Soft-switching converter, Zero voltage transition (ZVT),
PWM, Efficiency measurement, High-efficiency converter
Title of the Paper: A New Model for
Multi-Objective Load Curtailment Applied on Deregulated Environment
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Authors:
Sige Liu, Xiaoxin Zhou, Mingtian Fan, Haozhong Cheng
Abstract: In the deregulated environment, transmission congestion is one major
problem that needs to be handled in power system operation. This paper aims to
alleviate congestion using the multi-objective load curtailment (MOLC)
approach. The proposed MOLC approach optimizes the two objectives
simultaneous, namely the security margin and load curtailment cost. The
security margin is measured by a presented voltage instability indictor (VSI).
A fitting coefficient is adopted to combine the two conflicted objectives. The
primal dual interior point method (PDIPM) is adopted to solve the proposed
MOLC model. The effectiveness of both the improved PDIPM and the MOLC approach
has been tested and proven on the modified IEEE 30-bus system and IEEE 118-bus
system. The results obtained show that the proposed technique is able to
improve system security while yielding lower cost of load curtailment.
Keywords: Multi-objective
load curtailment, voltage instability indicator, security margin, cost of load
curtailment, fitting coefficient, primal dual interior point method
Issue 6, Volume 8,
June 2009
Title of the Paper: Timing-Driven
X-Architecture Routing Tree Construction among Rectangular and Non-Rectangular
Obstacles
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Authors:
Shu-Ping Chang, Hsin-Hsiung Huang, Cheng-Chiang Lin, Tsai-Ming Hsieh
Abstract: In this paper, we formulate a new X-architecture routing problem in
presence of non-rectangular obstacles, and propose an X-architecture
timing-driven routing algorithm to minimize the maximum source-to-sink delay
and the total wirelength simultaneously. First, a spanning graph is
constructed by the terminals and the corners of the obstacles. A minimal
spanning tree is then produced by performing searching algorithm to the
spanning graph. The feasible X-architecture is constructed by transforming all
slant edges of the minimal spanning tree. For the initial X-architecture
routing tree, the delay of source-to-terminal is estimated by the modified
Elmore delay model. According to the user defined delay threshold, an
efficient rerouting algorithm is used to fix the timing violated nets. The
critical terminals iteratively are rerouted by splitting two sub-trees and
merging into one tree. Compared to the routing result without rerouting, the
maximum source-to-sink delay is improved by 49.1% and only 2.5% of additional
total wirlength is increased.
Keywords: Timing-driven,
Non-rectangular obstacle, A-shaped pattern routing, Routing, X-architecture
Title of the Paper: Performance
Curve Fitting to the Operating Point of Fans
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Authors:
Cheng-Hsing Hsu, Kuang-Yuan Kung, Ching-Chuan Chang, Chia-Chuan Kuo
Abstract: This paper explores utilization of reverse engineering for
dimensionless analysis of the performance curve of the fan. Utilizing the
function curve and data provided in the reference material, this paper
identifies interactions among major parameters affecting the static pressure
and flow of the fan. Following the fitting, the equation P(X) is expressed via
Chebyshev polynomial. It simplifies the performance curve of the fan to match
the impedance curve of the system. The corresponding diagram obtained can be
used to predict the operating point of dimensionless performance curve of the
fan to match the impedance curve of the system. In comparison with the
conventional approach, the operating point of the research method registers an
error rate of under 4.97%. This method can help save the cost of experiment or
simulation, accelerate the speed of operating point search and reduce the size
of the fan databank.
Keywords: Chebyshev
polynomial, dimensionless, impedance curve, operating point, reverse
engineering, performance curve.
Title of the Paper: High-SFDR and
Multiplierless Direct Digital Frequency Synthesizer
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Authors:
Tze-Yun Sung, Hsi-Chin Hsin, Lu-Ting Ko
Abstract: This paper presents a hybrid COordinate Rotation DIgital Computer (CORDIC)
algorithm for designs and implementations of the direct digital frequency
synthesizer (DDFS). The proposed multiplier-less architecture with small ROM
(16 ? 4 -bit) and pipelined data path provides a spurious free dynamic range (SFDR)
of more than 84.4 dBc. A SoC (System on Chip) has been designed by 0.18μm 1P6M
CMOS, and then emulated on the Xilinx FPGA. It is shown that the hybrid CORDIC-based
architecture is suitable for VLSI implementations of the DDFS in terms of
hardware cost, power consumption, and SFDR.
Keywords: DDFS, hybrid
CORDIC, SoC, FPGA, SFDR
Title of the Paper: Reconfigurable
VLSI Architecture for FFT Processor
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Authors:
Tze-Yun Sung, Hsi-Chin Hsin, Lu-Ting Ko
Abstract: This paper presents a reusable intellectual property (IP) Coordinate
Rotation Digital Computer (CORDIC)-based split-radix fast Fourier transform (FFT)
core for orthogonal frequency division multiplexer (OFDM) systems, for
example, Ultra Wide Band (UWB), Asymmetric Digital Subscriber Line (ADSL),
Digital Audio Broadcasting (DAB), Digital Video Broadcasting – Terrestrial (DVB-T),
Very High Bitrate DSL (VHDSL), and Worldwide Interoperability for Microwave
Access (WiMAX). The high-speed 128/256/512/1024/2048/4096/8192-point FFT
processors and programmable FFT processor have been implemented by 0.18μm
(1p6m) at 1.8V, in which all the control signals are generated internally.
These FFT processors outperform the conventional ones in terms of both power
consumption and core area.
Keywords: IP, FFT, CORDIC,
split-radix, OFDM systems
Title of the Paper: Electromagnetic
and Thermal Model Parameters of Oil-Filled Transformers
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Authors:
Nikos E. Mastorakis, Cornelia Aida Bulucea, Marius Constantin Popescu,
Gheorghe Manolea, Liliana Perescu-Popescu
Abstract: The study of predictive control of temperature in oil-filled
transformers is performed in this work. In order to study transformers thermal
loss of life, complex models taking into account electrical and thermal
characteristics are required. Moreover, the precision of thermal models is
dependent upon the exactitude of the parameters. The work presented in this
article shows that, through electromagnetic similitude laws, for an
homogeneous series of transformers with different rated powers, the main
parameters required for the thermal model can be obtained. Different
methodologies to estimate thermal parameters with data from standardised
heat-run tests are compared. The foremost advantage of our alternative
methodology is its compactness, since parameters are obtained only from the
knowledge of transformer rated power. Theoretical results were compared with
data from transformer manufacturers and the good agreement between both
validates theoretical results is accomplished.
Keywords: Electromagnetic
similitude laws, Oil-filled transformers, Temperature control, Thermal
parameters
Title of the Paper: Non-Linear
Thermal Model for Transformers Study
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Authors:
Marius Constantin Popescu, Nikos E. Mastorakis, Cornelia Aida Bulucea,
Gheorghe Manolea, Liliana Perescu-Popescu
Abstract: This article begins with a study of transformer additional losses
due to the presence of non-sinusoidal loads, presents existing models to
represent these losses and proposes an original model. Consequent increment in
transformer loss of life is studied by means of a sensitivity analysis of the
model to transformer rated power, load amplitude, thermal inertia, profiles
correlation and harmonic spectrum content.
Keywords: Transformer
model, Non-sinusoidal loads, Thermal parameters
Title of the Paper: A Design of a Class
of Temperature Stabilization System and Implementation
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Authors:
Shieh-Shing Lin, Shih-Cheng Horng, Hen-Chia Hsu, Jia-Hau Chen, Tseng-Lin
Hsieh, Chih-Hao Ho, Kuang-Yao Lin
Abstract: In this paper, we proposed a design for a class of temperature
stabilization system based on the feedback control theory and the
corresponding technology of microchip MC89C51 and sensors theory. Besides, the
proposed design was implemented on a set of temperature control system to
determine whether the current status of fishes tank fitting fishes survival or
not. Therefore, we can control the temperature of fishes tank. There are three
stages in this design. First, we set the temperatures at the fish tank harming
fishes life are not suitable for the safety status. Second, we use the
MC89C51microprocessor combined with the A/D converter to process the analog
measuring temperatures of the sensor measurements into digital data. Finally,
a software program was designed to process the obtained digital data and
control the solid-state electric relay to increase or decrease the target
temperature of the water tank.
Keywords: MC89C51
microprocessor, A/D converter, Digital signals, Sensors, Feedback control
theory
Title of the Paper: Study of
Supercapacitor in the Application of Power Electronics
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Authors:
Yi Cheng Zhang, Li Wei, Xiaojun Shen, Haiquan Liang
Abstract: The purpose of this paper is to carry out a comprehensive study of
supercapacitor in the application of power electronics. According to the
practical demand and feasibility of power electronics, the modelling, voltage
management and topology of supercapacitor-based power system have been
discussed. Further more, in order to study the terminal behaviour of
supercapacitor and voltage balancing strategy for the application of power
electronics, a test bench based on HP-VEE has been built. The measurements on
supercapacitor’s capacitance, ESR (Equivalent serial resistance) and the
consistency of a group of serial supercapacitors, concerning practical
application have been suggested. As an example, Maxwell’s BCAP0120
supercapacitors have been selected for a 1.5kW hybrid supercapacitor- fuel
cell power system. Tests have been carried out and the results show that the
ESR is higher and the capacitance is lower compared with the values supplied
by manufacturers; and the consistency of them is good, thus the voltage
initialization strategy can be used for voltage balancing.
Keywords: Supercapacitor,
Power Electronics, Voltage-balancing, Capacitance, ESR
Title of the Paper: Modelling of a
SISO and MIMO Non Linear Communication Channel using Two Modelling Techniques
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Authors:
Nabiha Saidi, Okba Taouali, Hassani Messaoud
Abstract: In this paper, we consider the modelling of a Single Input Single
Output (SISO) and Multi Input Multi Output (MIMO) non linear communication
channels using two modelling techniques. The first titled Volterra model built
using Volterra series and possesses several important properties that make
them very useful for the modelling and analysis of non linear systems and the
second named RKHS model developed on a particular Hilbert Space the kernel of
which is reproducing. This space known as Reproducing Kernel Hilbert Space (RKHS)
uses the statistical learning theory to provide RKHS model.The performances of
both models in SISO case and in MIMO case are evaluated and the results were
successful.
Keywords: Modelling, SISO,
MIMO, RKHS, Volterra, communication channel
Title of the Paper: An Analysis of
the Instability Mechanism of a Low - Current Metal Vacuum Arc for Silver Based
Cathode Material
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Authors:
Narong Mungkung, Tanes Tanitteerapan, Somchai Arunrungrusmi, Weerachai
Chaokumnerd, Toshifumi Yuji
Abstract: The purpose of this research was to investigate instability
phenomena in low-current metal vacuum arc using the calculation data
comparison with the experimental data. The instability phenomena are
characterized by noise on the current trace prior to the actual current
chopping. The instability current was investigated for various electrode
materials. A cathode spot model is used to analyze the instability phenomena
of vacuum arc. The experiment of major commercial switching electrode such as
Ag-Pd is performed in this study. To study the parameters affecting the
stability arc factors, the parameter scan of cathode materials and ion current
fraction by numerical analysis, it was found that the critical current of the
stable current is highly dependent on the thermal conductivity of the cathode
material. However, the thermal conductivity effect on the instability
phenomena of low-current metal vacuum arc was important for low surge
switching electrode material development. An electrostatic probe was used to
confirm these findings, and the analytical results were found to be similar to
the measurement results. This is very important result for the development of
cathode materials for low-surge vacuum interrupters.
Keywords: Cathode spot
model, instability, thermal conductivity, silver
Issue 7, Volume 8,
July 2009
Title of the Paper: Nonlinear
Feedback System for an Inverter-Based Ring Oscillator
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Authors:
Chingyei Chung, Shou-Yen Chao, M. F. Lu
Abstract: In integrated circuits, ring oscillator (RO) has many applications.
In these applications, how to obtain the accurate oscillation frequency is an
important issue for the design. In this paper, we explore the feedback problem
of a N-stage ring oscillator. This paper proposes a more rigorous approach to
analyze the ring oscillator. It can be approximated that the feedback system
of a ring oscillator can be a nonlinear Lur’e problem. With this Lur’e
problem, circle criterion can be used to determine the stability of overall
feedback system. With this Lur’e problem, he describing-function method is
used to determine the oscillation frequency of the ring oscillator. A new
formula will be presented. It can be also observed that if N (number of
inverters) is large enough, the proposed formula will approach the
conventional formula. Moreover, with describing function method, a “necessary
condition”for the existence of fundamental mode and higher order modes of
oscillations are presented. Furthermore, it can be shown that as N ?7 and the
voltage gain is large enough; the higher harmonic oscillation may exists.
Finally, with Tsypkin Function method, a more accurate formula for the
oscillation frequency of ring oscillator will be presented. Finally,
Simulation examples will illustrate these results.
Keywords: Ring oscillator,
describing function, Tsypkin function, Extended Nyquist Diagram
Title of the Paper: A Design Method in
CMOS Operational Amplifier Optimization Based on Adaptive Genetic Algorithm
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Authors:
Jianhai Yu, Zhigang Mao
Abstract: A new method based on adaptive GA(genetic algorithm) for optimizing
the parameters of CMOS operational amplifier is presented in this paper. The
synthesis of the Op-amp (operational amplifier) can be translated into
multiple-objective optimization task, in which a large number of
specifications have to be taken into account. Such as DC-gain, bandwidth of
unity gain, phase-margin, power, noise and others. The feature of the method
is that combining the skills of manual experience of analog circuits design
and genetic algorithm, through adjusting the GA with the evolution process,
the problems of convergence and multiple objective optimization tasks can be
solved; and operational amplifiers for different use can be designed depending
on various performance specifications. The results of groups of simulation
show that this method can optimize the parameters of analog circuits
accurately and efficiently.
Keywords: Genetic
algorithm (GA); CMOS analog circuit; operational amplifier; evolution,
fitness, sizing
Title of the Paper: Applying FPGA-based
Chip to Apparent Power and Power Factor Measurement Considering Nonsinusoidal
and Unbalanced Conditions
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Authors:
Shu-Chen Wang, Chi-Jui Wu, Sheng-Wen Yang
Abstract: This paper proposes a field-programmable gate array (FPGA)-based
integrated circuit (IC) for computing apparent powers and power factors of
power systems. In a nonsinusoidal and unbalanced three-phase power system, the
calculation of apparent powers and power factors has many definitions. Load
characteristics of harmonic and unbalance can not be expressed in the
traditional apparent power and power factor, which only consider the
fundamental and three-phase balanced sinusoidal conditions. This paper
utilizes the FPGA chip to develop the platform to implement the calculation
methods of apparent powers and power factors. The proposed design scheme is
developed using the very high speed integrated-circuit hardware description
language (VHDL), which provides high flexibility and technology independence.
This paper discussed the effective power and power factor, the arithmetic
power and power factor, and the fundamental power and power factor. The design
of filters for the computation of fundamental frequency components is given.
ModelSim is used at first to simulate the calculation of apparent powers and
power factors to ensure the accuracy of timing and function. Research results
show that the designed chip can compute accurately the apparent powers and
power factors considering the effects of nonsinusoidal and unbalanced
conditions.
Keywords: FPGA, SoC, Power
Factor, Harmonic, Unbalanced Power System
Title of the Paper: Design and
Implementation of a System Bus – SPI Bridge for Wireless Radio Prototyping
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Authors:
Mohamad Yusri Mohamad Yusof, Devi Prasad, Smruti Santosh Palai
Abstract: Prototyping of wireless radio is one of the major stages of the
entire development process. It invariably has an interface to the Analog to
digital converters (ADC) / Digital to Analog converters (DAC) and RF front
end. This paper discusses in detail the design issues and solutions for
baseband- RF front end interface, of a wireless radio. In these kinds of
systems, the FPGA tends to be connected to the baseband DSP processor through
the system bus. The FPGA is then used to implement additional baseband
processing, hardware accelerators, ADC/DAC interfaces and RF control, to name
a few. The DSP processor will need to communicate with these components
through the system bus. Some of these components require high bandwidth and
others requires low bandwidth from the system bus. There is a need for a
design approach where that avoids slow interfaces, such as RF control
interface, from hogging the system bus, which in turn will affect the overall
performance of the entire system. This paper presents a System Bus-SPI bridge
design approach to mitigate the interfacing issues in wireless system
prototyping, especially when the supporting hardware, like RF module, is
predefined. The proposed design enables the DSP Processor to access the System
Bus concurrently while the SPI programming is in progress. Verilog hardware
description language is used to design the System bus –SPI Bridge and Modelsim
is used to verify the functionality of the design. The proposed design was
implemented on an Altera STRATIX II FPGA.
Keywords: FPGA, SPI,
Prototyping, System Bus, Wireless radio, Shared Bus
Title of the Paper: Multilayer
Perceptron and Neural Networks
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Authors:
Marius-Constantin Popescu, Valentina E. Balas, Liliana Perescu-Popescu, Nikos
Mastorakis
Abstract: The attempts for solving linear inseparable problems have led to
different variations on the number of layers of neurons and activation
functions used. The backpropagation algorithm is the most known and used
supervised learning algorithm. Also called the generalized delta algorithm
because it expands the training way of the adaline network, it is based on
minimizing the difference between the desired output and the actual output,
through the downward gradient method (the gradient tells us how a function
varies in different directions). Training a multilayer perceptron is often
quite slow, requiring thousands or tens of thousands of epochs for complex
problems. The best known methods to accelerate learning are: the momentum
method and applying a variable learning rate. The paper presents the
possibility to control the induction driving using neural systems.
Keywords: Backpropagation
algorithm, Gradient method, Multilayer perceptron, Induction driving
Title of the Paper: Production
Techniques of PV's and Polycrystalline PV Performance Analyses for Permanent
Resistive Load
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Authors:
Safak Saglam, Gokhan Kocyigit, Nevzat Onat
Abstract: Photovoltaic (PV) panels which are used to convert solar energy to
electrical energy one of the fastest growing source on energy sector. Their
efficiencies are increasing day by day with new technologies. Photovoltaic’s
average efficiencies are still 15-20% in daily usage. In this study general
photovoltaic production techniques are explained briefly. New technological
developments affect these production techniques so the new methods on
photovoltaic production are examined. During one year period polycrystalline
PV performance which feeds the permanent resistive load is tested
experimentally for Istanbul-Goztepe.
Keywords: Photovoltaic,
D.C. Loads, Energy Consumption, Production Techniques
Title of the Paper: Digitally
Controllable Delay Element Using Switched-Current Mirror
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Authors:
Sekedi B. Kobenge, Huazhong Yang
Abstract: Controllable delay elements are essential for shifting the edges of
signals in many digital and mixed-mode signal processing integrated circuits.
Digitally programmable delay elements (DPDEs) are more flexible, less
susceptible to noise and exhibit more robustness than their analog
counterparts. In this paper, a partially programmable and a fully programmable
delay elements are proposed. Together with a switched current mirror, a gate
decoupling technique is applied to the former while a Schmitt type inverter is
used in the later structure to achieve more significantly reduced static and
short-circuit current. The delay elements are implemented in a 0.18um
technology and simulation results with a 1V power supply show a more than 40%
power saving while operating at a speed of 450MHz in both structures.
Keywords: Current mirror,
delay element, inverter, low power, Schmitt trigger, switched current
Title of the Paper: On-line
Partial Discharge Monitoring System and Data Processing Using WTST-NST Filter
for High Voltage Power Cable
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Authors:
Hui Wang, Chengjun Huang, Li Zhang, Yong Qian, Junhua Liu, Linpeng Yao, Canxin
Guo, Xiuchen Jiang
Abstract: Defects inside insulation of HV XLPE cable accessories can lead to
partial discharge (PD) activity. When PD activity happens, leakage current may
flow through the grounded line. To acquire the PD current signal, one
practicable and effective method is placing a high frequency current
transformer (HFCT) winding the grounded line. In order to measure the
insulation degradation, a partial discharge on-line monitoring system is
developed and reported in this paper. Through the field test, the presented
monitoring system is effective and available for power cable in the condition
based maintenance (CBM). However, on-site partial discharger detection on XLPE
cables and cable accessories are very difficult of variable noise
interference, which gives much trouble to partial discharge detecting. This
paper introduced an adaptive filter stationary-non stationary filter based on
the wavelet transform (WTST-NST) to de-noise the stationary noise interference
in partial discharge detecting. The proposed method is a wavelet domain
filtering technique, based on the iterative multi-resolution decomposition
reconstruction (MRD-MRR) with hard threshold, for extracting PD signals from
stationary interference noise. Quantitative and qualitative analysis of the
experimental results, while using the WTST-NST filter to PD signals recorded
from power cables, prove that the ability to extract the PD from noise hidden
in it.
Keywords: Power cable,
Adaptive WTST-NST filter, On-line monitoring, Partial Discharge, MRD-MRR
Algorithm, Stationary noise interference, condition based maintenance(CBM)
Title of the Paper: Studies on
Multi-Agent Based Partial Discharge Online Monitoring System for High Voltage
Apparatus
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Authors:
Linpeng Yao, Chengjun Huang, Li Zhang, Yong Qian, Hui Wang, Junhua Liu, Canxin
Guo, Xiuchen Jiang
Abstract: In the contribution, the authors applied the Multi-Agent methodology
to the partial discharge (PD) online diagnosis for high voltage apparatus, and
a PD diagnosis Multi-Agent system for high voltage apparaus was implemented.
Based on the investigation of problems existing in partial discharge detection
and evaluation, such as preprocessing, features extraction, trend and
fingerprint analysis, corresponding methods and schemes were described. The
framework of the Multi-Agent system and detailed design of each agent were
also depicted. And furthermore, a complete system implemented by Zeus are
established for performing evaluation in field application.
Keywords: High voltage,
Partial discharge, Multi-Agent, Monitoring, .Net Framework, Zeus
Issue 8, Volume 8,
August 2009
Title of the Paper: Research of
Partial Discharge Localization Method in GIS Based on UHF Technique
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Authors:
Junhua Liu, Ming Yao, Chengjun Huang, Linpeng Yao, Hui Wang, Xiuchen Jiang
Abstract: Some small defects like fix protrusion or free moving particles
exist in GIS can induce partial discharge (PD) which will deteriorate
insulation condition and eventually cause insulation breakdown when GIS are in
service. It is very important to detect and locate the PD signal for early
detection of insulation defects and preventing insulation failure. Time of
flight method which based on Ultra High Frequency (UHF) technique is widely
used for locating PD in GIS for the merits such as simple principle and easy
implementation. But in application, the time of flight method can hardly be
applied effectively and will induce errors if the initial pulse of the PD
signal is small and blurry or its signal-to-noise ratio (SNR) is too low. In
this paper, the characteristics of electromagnetic wave (EM-wave) propagation
route in GIS were investigated and a new localization method was proposed. The
simulation and experiment results show that the EM-wave signals induced by PD
in GIS are related with EM-wave propagation routes, which were decided by the
location of PD source and detector’s position. The experiment results show
that the proposed PD localization method which based on the characteristics of
EM-wave propagation route can locate the PD signal well and effectively in the
case that the initial pulse of PD signals is very small and blurry when PD
source locates near the outer conductor of GIS.
Keywords: GIS, partial
discharge, UHF method, localization, EM-wave, propagation route
Title of the Paper: Design of a
Synchronous FFHSS Modulator on a FPGA with System Generator
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Authors:
Santiago T. Perez, Jesus B. Alonso, Carlos M. Travieso, Miguel A. Ferrer, Jose
F. Cruz
Abstract: This work is based on a previous Fast Frequency Hopping Spread
Spectrum (FFHSS) transceiver designed for wireless optical communications. The
core of the transmitter was a discrete Direct Digital Synthesizer (DDS). In
the first prototype the DDS control and the digital synchronization signal
were generated using a Programmable Logic Device (PLD), besides a discrete
external filter was necessary to eliminate high frequency components of
digital synchronization signal and generate analog synchronization signal. The
FFHSS and analog synchronization signals were emitted by two separated Light
Emitting Diodes (LED) to avoid adding them with discrete analog circuits. The
peak emission wavelength of the LED was 650 nanometers. The objective of this
work is redesign the modulator on a Field Programmable Gate Array (FPGA) using
System Generator from Xilinx and analyse the performances of this design
methodology. System Generator is one design tool in Simulink of Matlab. It
allows fast design of digital systems using block diagrams. The compilation
generates the files necessary for the Integrated System Environment (ISE) for
FPGA of Xilinx, where the description of the circuit is obtained in a standard
hardware description language. In ISE it is possible to compile the hardware
description language files, simulate the system, assign pins, obtain the
program file and program the FPGA.
Keywords: Spread spectrum,
modulator, DDS, FPGA, System Generator, Xilinx, Simulink, HDL, floating point,
fixed point
Title of the Paper: Assessment of
Three-phase Induction Motor Dynamic Regimes Following Ecosystem Patterns
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Authors:
Nikos E. Mastorakis, Cornelia A. Bulucea, Doru A. Nicola
Abstract: Within the present industrial society the humans further challenges
are doubtless related to a sustainable industrial metabolism, integrating
industrial activity into ecological systems. An approach of technical systems
and ecological systems as parts of the same system, the industrial ecosystem,
could provide a holistic view of the interactions and symbiosis
interrelationships among human activities, technical systems operation and
ecological processes. In this study are pointed the ecosystem key-features
suitable for the electrically driven transportation systems analysis. By
modeling the electrical traction machines dynamic regimes according to an
industrial ecosystem pattern, one could attempt to minimize the environmental
impacts and optimize the efficiency of energy use within the transportation
systems operation.
Keywords: Dynamic Regimes,
Induction Machine, Industrial Ecosystem, Transportation System
Title of the Paper: Parameters
Modelling of Transformer
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Authors:
Marius-Constantin Popescu, Gheorghe Manolea, Nikos Mastorakis, Liliana
Perescu-Popescu
Abstract: This paper analyses transformer loss of life attending to the
realistic variability of both structural and functional parameters. The
article begins with the modelling of load and ambient temperature profiles, by
means of chronological series theory. A simple additive model is proposed and
validated with realistic data, loss of life resulting from probabilistic
functional and structural parameters is analysed through a sensitivity study.
Keywords: Transformer
thermal, Estimate thermal parameters
Title of the Paper: Network
Optimization by Generalized Methodology
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Authors:
Alexander Zemliak, Ricardo Pena
Abstract: The design process for analog network design is formulated on the
basis of the optimum control theory. A special control vector is defined to
redistribute the compute expensive between a network analysis and a parametric
optimization. This redistribution permits the minimization of a computer time.
The problem of the minimal-time network design can be formulated in this case
as a classical problem of the optimal control for some functional
minimization. The principal difference between the new approach and before
elaborated generalized methodology is presented. This difference is based on a
higher level of the problem generalization. In this case the structural basis
of different design strategies is more complete and this circumstance gives
possibility to obtain a great value of computer time gain. Numerical results
demonstrate the efficiency and perspective of the proposed approach.
Keywords: Time-optimal
design algorithm, control theory formulation, general methodology
Title of the Paper: Analog Blocks
Design Automation
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Authors:
Hassen Aziza, Annie Perez, Emmanuel Bergeret
Abstract: The purpose of this paper is to present an automated design
methodology for analog blocks. This method focuses on analog blocks design
parameters automatic generation according to specific design constraints. This
method is based on analog circuits’ mathematical models. These models are
generated thanks to a “Design Of Experiment” (DOE) technique. The DOE
technique takes as input electrical simulation results of a given circuit for
different component geometries. DOE generates polynomial equations of the
circuits’ outputs. Using these equations and according to given design
specifications, the methodology provides the most suitable design parameter
values. This efficient methodology reduces extensive simulations to find the
right design parameters with respect to circuit accuracy.
Keywords: Analog circuits,
design automation, modelling, Charge Pumps (CP), Current References (CR)
Title of the Paper: Cooperative-PSO-Based
PID Neural Network Integral Control Strategy and Simulation Research with
Asynchronous Motor Controller Design
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Authors:
Piao Haiguo, Wang Zhixin, Zhang Huaqiang
Abstract: This paper focuses on the design of robustness controller for
asynchronous motor. a new PID neural network-integral (PIDNN-I) synthesis
control strategy is proposed for the controller design, in which NARMA-L2, an
approximated model of nonlinear auto regressive moving average(NARMA) model,
is employed to represent the input-output behavior of the motor and gives out
the expected control input. PID neurons network (PIDNN), as a kind of novel
neural network model with dynamic characteristics, is adopted in NARMA-L2 to
identify the motor. PIDNN integrates the advantages of PID with those of
artificial neuron network. However, the conventional back-propagation (BP)
algorithm, which easily gets trapped in local minimum and is being adopted in
the current model, constrains the identifying ability of PIDNN so as to harm
to the completion of the controller design. Particle swarm optimization (PSO)
algorithm, a new population-based evolutionary global optimization method, is
proposed to replace the BP algorithm to train the neurons model. Cooperative
particle swarm optimization (CPSO), an improved version of cooperative random
learning particle swarm optimization (CRPSO), is put forward to enhance the
performances of the conventional PSO in the design. Due to the existence of
the tracking error caused by approximate error between identifying and real
system, integral (I) control is introduced into the design, namely adopting
PIDNN control in large tracking error scale and PIDNN-I control in small
tracking error scale. Compared with conventional PID control strategy,
simulation results demonstrate that the CPSO-based PIDNN-I synthesis control
strategy has improved the control performances of asynchronous motor in
robustness and accuracy efficiently.
Keywords: NARMA-L2, PID
neural network, integral, synthesis control, asynchronous motor, BP, PSO,
Nonlinear, Cooperative particle swarm optimization
Title of the Paper: Voltage
Control Scheme in Distribution Network with Double Feed Induction Generator
Wind Farm
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Authors:
Jingjing Zhao, Xin Li, Jutao Hao
Abstract: This paper presents the particle swarm optimization (PSO) for
reactive power and voltage control (Volt/Var Control) in distribution system
considering DFIG wind farm. In this paper, the reactive power output of DFIG
wind farm has been considered as the control variables in the Volt/Var Control
scheme by considering the reactive power compensation capability of DFIG. The
minimization of total system real power loss and voltage deviation are
utilized as an objective and the PSO is used to determine the reactive power
output of DFIG wind farm, tap positions of load tap changer transformers (LTC)
and numbers of the capacitor banks. Finally, the proposed scheme is applied to
the 33-node distribution system. The results indicate that the proposed Volt/Var
control scheme can improve the voltage profiles of distribution networks on a
large scale.
Keywords: Distribution
network; DFIG wind turbine; wind farm; Volt/Var Control; particle swarm
optimization
Title of the Paper: Experimental
Wavelet Transient-State Analysis of Electrical Machines Directly Feeding by
Photovoltaic Cells
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Authors:
Nevzat Onat, Ismail Kiyak, Gokhan Gokmen
Abstract: Solar electric systems -also known as photovoltaic (PV) systems-
have very little impact on the environment, making them one of the cleanest
power-generating technologies available. While they're operating, PV systems
produce no air pollution, hazardous waste, or noise, and they require no
transportable fuels. In PV System design, the selection and proper
installation of appropriately-sized components directly affect system
reliability, lifetime, and initial cost. The features of the receivers fed
from PV systems have a direct impact on the cells; namely, the power
generators of the system. System behavior may change in receivers equipped
with electrical machines fed from photovoltaic’s, depending on the
characteristics of the machine used. The fact that in the design phase of the
photovoltaic systems which will feed electrical machines that the current
drawn by any electrical machines at the startup is higher than the nominal
operating current should be taken into account. In this study, the startup and
nominal operating behaviors of electrical machines directly connected to
photovoltaic system (not having any storage system or controller system) were
empirically examined, obtained power values (in p.u.) were decomposed to
sub-frequency components by means of the discrete wavelet transform than they
were compared to each others.
Keywords: Photovoltaic
Cells, Transient State, Electrical Machines, Wavelet Filter Bank,
Multiresolution Analysis
Title of the Paper: A Reconfigurable
FEC System based on Reed-Solomon Codec for DVB and 802.16 Network
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Authors:
Lamia Chaari, Mohamed Fourati, Nouri Masmoudi, Lotfi Kamoun
Abstract: This article proposes, a reconfigurable FEC system based on
Reed-Solomon codec for DVB and WiMax networks. The proposed architecture
implements various programmable primitive polynomials. A lot of VLSI
implementations have been described in literature. This paper introduces a
highly parametrical RS-coder-decoder on FPGAs. The implementation, written in
a hardware description language (HDL), is based on an Berlekamp massey, Chain
and Formey Algorithms. We have defined an advanced RS encoder-decoder
architecture based on parameterization approach which is a key solution for
software defined radio (SDR) systems. Our parameterization approach is used in
order to implement on FPGA a generic RS coder-decoder for DVB and WiMax
networks. IEEE Std. 802.16 specifies that the codec performs a variable number
of check symbols in a codeword ( ranges from 0 to 32, inclusive). The value of
check symbols are specified for each burst profile by the MAC layer according
to cross layer concept.
Keywords: Reedsolomon,
Berlekamp massey, Chain, Formey, FPGA, implementation , VHDL, WiMax, DVB
Title of the Paper: Wind Parks
Equivalent Models using System Identification Techniques based on Nonlinear
Model Structures
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Authors:
F. D. Kanellos, G. J. Tsekouras, N. E. Mastorakis
Abstract: In this paper models of Wind Parks (WPs) appropriate for simulation
purposes of large power systems with high wind power penetration are
developed. The proposed models of the WPs are developed using system
identification theory with NARX model structures. Data obtained from the
simulation of detailed WP models are used for system identification. The
obtained models are general and they can be applied to different
configurations of WPs as only system's input/output data are used and not any
internal states of the model. Simulation results confirm the accuracy and the
advantages of the proposed wind parks equivalent models.
Keywords: Wind parks, wind
turbines, modeling, system identification, wind integration
Issue 9, Volume 8,
September 2009
Title of the Paper: New Achievements in
Assisted Movement of Visually Impaired in Outdoor Environments
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Authors:
Ivan Bogdanov, Virgil Tiponut, Radu Mirsu
Abstract: In the last years, the traditional tools used by visually impaired
to navigate in real outdoor environments (white cane and guiding dogs) are to
be substituted with electronic travel aids (ETA). These devices are capable to
improve the mobility of blind users in unknown or dynamically changing
environment, but up to date no ETAs have been practically implemented. In this
paper, the most important theoretical and practical results obtained in the
field of ETAs are presented first. Some original results of the author’s team,
including new concepts in this field, like integrated environment for assisted
movement, acoustical virtual reality (AVR), bioinspired solutions are then
discussed in more detail. Conclusions and the further developments in this
area are also presented.
Keywords: Visually
impaired individuals, electronic travel aids, integrated environment for
assisted movement of visually impaired, acoustical virtual reality
Title of the Paper: Harmonic-Controlled
Three-Way Doherty Amplifier with Improved Linearity
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Authors:
Natasa Males-Ilic, Aleksandar Atanaskovic, Bratislav Milovanovic
Abstract: In this paper the efficiency and linearity behavior of three-way
Doherty amplifier is analyzed. The amplifier is designed in the configuration
with two quarter-wave impedance transformers in the output combining circuit
with LDMOSFETs in carrier and peaking amplifiers. The signals for
linearization (the fundamental signals’ second harmonics-IM2 and fourth-order
nonlinear signals-IM4 at frequencies that are close to the second harmonics)
are extracted at the output of peaking cells biased at various points. The
Doherty amplifier is designed with the frequency diplexer at the outputs of
the Doherty cells that separates the fundamental signals and signals for
linearization. The diplexer includes harmonic control circuit (HCC) which in
combination with matching circuits, provides an optimal impedance for an
adequate power level of signals for linearization, and either open circuit for
the third harmonics (HCC class-3F) or short circuit for the third harmonics (HCC
class-3IF). The linearization technique results in the suppression of the
third- and fifth-order intermodulation products of Doherty amplifier.
Keywords: Doherty
amplifier, class-F, harmonic control circuit (HCC), linearization,
power-added-efficiency, second harmonics, fourth-order nonlinear signals,
third- and fifth-order intermodulation products
Title of the Paper: Modified Direct
Torque Control for Single-phase Induction Motor Drives
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Authors:
Thanatchai Kulworawanichpong, Tawat Chuchit
Abstract: This paper illustrated a modified strategy of direct torque control
for single-phase induction motors. The proposed strategy was based on
classical six-sector hysteresis-type direct torque control scheme developed by
using stator reference frame. The modification made in this paper led to two
control strategies called modified six and twelve sectors, respectively. A
switching table was derived based on the voltage vectors generated by the
three-leg two-phase inverter topology. Simulations were carried out and
performance analysis was presented.
Keywords: Single-phase
induction motor drives, Direct torque control, Hysteresis control, Six-sector
based DTC, Twelve-sector based DTC
Title of the Paper: Mobile Robot Path
Planning using Exact Cell Decomposition and Potential Field Methods
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Authors:
Dusan Glavaski, Mario Volf, Mirjana Bonkovic
Abstract: In this paper two classic path planning procedures have been
explained and adopted to reduce computational time. When studying mobile
robotics and robot motion planning, there is always a gap which exists between
theoretical achievements and practical considerations of the described
methods. This paper clearly overrides the mentioned problem describing
minutely the procedures necessary for practical implementations and simulation
in the Matlab and MobileSim environment. The algorithms have been presented
together with their pseudo codes. The simulation results clearly show the
advantages and drawbacks of each of the method.
Keywords: Path planning,
mobile robot, exact cell decomposition, potential field
Issue 10, Volume 8,
October 2009
Title of the Paper: Modelling and
Simulations of Oil-filled Transformer Loss-of-Life Models
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Authors:
Marius-Constantin Popescu
Abstract: The purpose of this article is to analyse the tansformer thermal and
loss of life models will be studied. Based on the thermal model adopted by
International Standards, small improvements to increase model accuracy are
presented and a comparative study of resulted accuracy under different load
and ambient temperature profiles is performed.
Keywords: Loss of life
models, Modelling thermal parameters, Oil-filled transformer
Title of the Paper: Simulation the
Functionality of a Web Cam Image Capture System
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Authors:
Toadere Florin, Nikos E. Mastorakis
Abstract: The goal of this paper is to imagine the functionality of a web
camera image capture system. In order to do that we illuminate a spectral
image, we capture the reflected light using an achromatic doublet and finally
we focus the light on a CCD. We are interested to see what happens as the
image propagates trough the image capture pipeline. We present an illumination
algorithm, we design the achromatic doublet, we use an aperture and we compute
the CCD transfer function. Using the CCD integration times we take several
images in rapid succession, at different exposure levels; then we blend the
images in order to obtain a HDR (high dynamic range) image. We consider the
image capture system to be axial and the light is orthogonal to the system.
Keywords: Spectral image
illumination, achromatic doublet design, CCD transfer function, HDR image,
photon shot noise, colors enhancement
Title of the Paper: Selecting Feature
Detectors for Accurate Visual Odometry
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Authors:
Aldo Cumani, Antonio Guiducci
Abstract: This work analyzes the performances of different feature
detectors/descriptors in the context of incremental path estimation from
passive stereo vision (Visual Odometry). Several state-of-the-art approaches
have been tested, including a fast Hessian-based feature detector/descriptor
developed at INRIM. Tests on both synthetic image sequences and real data show
that in this particular application our approach yields results of accuracy
comparable to the others, while being substantially faster and much more
reliable.
Keywords: Robot
localisation, Stereo vision, Visual odometry, Feature descriptors, Feature
detectors
Title of the Paper: Parallel
Architecture for the Solution of Linear Equations Systems Based on Division
Free Gaussian Elimination Method Implemented in FPGA
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Authors:
R. Martinez, D. Torres, M. Madrigal, S. Maximov
Abstract: This paper presents a parallel architecture for the solution of
linear equations systems based on the Division Free Gaussian Elimination
Method. This architecture was implemented in a Field Programmable Gate Array (FPGA).
The division-free Gaussian elimination method was integrated in identical
processors in a FPGA Spartan 3 of Xilinx. A top-down design was used. The
proposed architecture can handle IEEE 754 single and double precision
floating-point data and the architecture was implemented in 240 processors.
Also, an algorithmic complexity of O(n2) was obtained using a n2 processors
scheme that perform the solution of the linear equations. Moreover, the
parallel division-free Gaussian elimination method, the architecture/s data
distribution and the internal processor-element (PE) architecture are
presented. Finally, this paper presents the obtained simulation results and
synthesis of the modules designed in very high-speed integrated circuit
hardware description language (VHDL) using 40 and 100 Mhz frequencies.
Keywords: Field
Programmable Gate Array (FPGA), Parallel Processing, Parallel Architectures,
linear systems equations, Division Free Gaussian elimination Method
Issue 11, Volume 8,
November 2009
Title of the Paper: A Survey on
Modeling and Simulation of a Signal Source with Controlled Waveforms for
Industrial Electronic Applications
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Authors:
Nazih Moubayed, Claude Bayeh, Mouafac Bernard
Abstract: In industrial electronic systems, power converters with power
components are used. Each controlled component has its own control circuit. In
this paper, the authors propose an original control circuit in order to
replace the different existing circuits. The proposed circuit is the
representation of an elliptical trigonometry function. Thus, by varying the
value of one of its parameter, the output waveform will change. Finally,
Labview and Matlab simulation results of the studied circuit are presented and
discussed.
Keywords: Power
converters, power electronics, power components, mathematics and trigonometry
Title of the Paper: Transient
Characteristics Analysis Based-on Circuit Models for a High-Speed Rail System
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Authors:
Kuei-Hsiang Chao, Pi-Yun Chen, Chun-Hsin Cheng
Abstract: The main purpose of this study is to analyze the current leakage of
the power grid due to the change in speed of high-speed rail (HSR). First,
using PSIM software as the fundamental basis, this study constructed an
overall HSR circuit-based model system, including Scott transformer,
auto-transformer, and the track equivalent circuit and grounding system. In
addition, this paper sought to study the current leakage transient responses
of a train’s change in speed using this equivalent circuit model. Through
simulation results, the study found that the dramatic change in DC voltage
from a change in the speed of electric locomotives causes current leakage
flowing through the high-speed rail power grid and a rise in ground potential.
The study’s analysis results provide possible performance improvements to the
high speed rail’s electric locomotives during changes in speed.
Keywords: High-Speed Rail
System, Scott Transformer, Leakage Current, Transient Behavior
Title of the Paper: Charge Equalization
Based-on Three-Level NPC Converter for Series Connected Battery Strings
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Authors:
Kuei-Hsiang Chao, Chia-Chang Hsu, Chun-Hsin Cheng
Abstract: The main purpose of this paper is to design a charge equalization
circuit for series connected lead-acid batteries. The charger utilizes a
three-level neutral point clamped (NPC) AC/DC converter with voltage balance
control to charge the series connected rechargeable battery strings. This
paper details the operation principles of the charge equalization circuit
under different operation modes and derives the governed equations. The
proposed charge equalization circuit can not only regulate the power factor of
AC source side, but also can balance the charge voltage for series connected
rechargeable batteries. Finally, some simulation results are made to
demonstrate the effectiveness of the charge equalization circuit scheme
presented in this paper.
Keywords: Lead-Acid
Battery, Charge Equalization Circuit, Three-Level Converter, Voltage Balance
Control, Neutral Point Clamped (NPC) Converter
Title of the Paper: Longitudinal
Control of Hybrid Electric Buses using Traction Motor and Pneumatic Braking
System
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Authors:
Jie Shu, Yong Zhang, Chengliang Yin
Abstract: Additional energy source of hybrid electric buses comprises new
control tasks. One of the main challenges of hybrid electric buses is the
integrated control between traction motor and brakes, associated with which is
the problem of switching traction motor and brakes. Existing control
techniques only provide a result of frequent switch and jerky ride. In this
paper, we propose a control strategy including two control laws, which are
calculated simultaneously to optimize a certain tracking criterion by a fuzzy
adaptive algorithm. Considering parametric uncertainties, the two control laws
are used to determine whether to activate the traction motor or the pneumatic
brake. The stability and convergence properties of the longitudinal brake
control system are analytically proved by using Lyapunov stability theory and
Barbalat’s lemma. We examine the proposed algorithm with different mass
uncertainties and the simulation results demonstrate stable behaviors when two
buses drive into a bus station.
Keywords: Hybrid electric
bus; platoon performance; coordinated control; fuzzy adaptive control; sliding
mode control
Issue 12, Volume 8,
December 2009
Title of the Paper: Non-Uniform
Sampling Delta Modulation-Principles of Parameters Design
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Authors:
Ryszard Golanski, Jacek Kolodziej, Stanislaw Kuta
Abstract: The parameters design of 1-bit adaptive delta modulations (ADM)
systems with uniform sampling rate is well known. Analytical study of delta
modulations with sampling rate adaptation have been carried out few years ago.
The described ADM systems encode the input signal by changing the sampling
intervals and/or step size according to its time-varying slope
characteristics. A proposition for design of the parameters of delta
modulators with adapting the sampling frequency have been presented. The
relation between the boundary values of sampling frequency changes, step size
and input power level have been described by the LambertW function. The method
presented in this study are useful for parameters design of NS-DM and ANS-DM
modulations.
Keywords: Adaptive delta
modulation, non-uniform sampling, sampling frequency adaptation, quantization
step size, LambertW function
Title of the Paper: Direction of Sound
Wave Arrival Determination Using Time-Delay Estimation and Beamforming Methods
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Authors:
Petr Dostalek, Vladimir Vasek, Jan Dolinay
Abstract: This paper deals with direction of sound wave arrival determination
using time-delay estimation and beamforming methods with utilization of static
microphone array with fixed geometry configuration. Theoretical part describes
main principle of both methods and possibility of program implementation.
Experimental part proposes hardware design of the sensory systems separately
for time-delay estimation and beamforming evaluation methods due to different
requirements on microphone array structure. Developed localization system is
based on standard personal computer equipped with Advantech PCI-1716
multichannel data acquisition device.
Keywords: Audio source
localization, microphone array, direction of arrival, time-delay estimation,
beamforming, signal processing
Title of the Paper: On Structure of the
Control Vector for Minimal-Time Networks Design Strategy
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Authors:
Alexander Zemliak, Miguel Torres
Abstract: The generalized methodology for the electronic networks optimization
was elaborated by means of the optimal control theory approach. In this case
the problem of the electronic system design is formulated as a classical
problem of functional minimization of the optimal control theory. The minimal
time system design algorithm was defined as a controllable dynamic process
with an optimal control vector. By this methodology the aim of the system
design process with minimal computer time is presented as a transition process
of some dynamic system that has the minimal transition time. The optimal
position of the control vector switch points was determined as a principal
characteristic of the minimal-time system design algorithm. The special
function that is a combination of Lyapunov function of the design process and
its time derivative was proposed to predict the optimal control vector to
construct an optimal system design algorithm.
Keywords: Minimal-time
system design, circuit optimization, control theory application, Lyapunov
function
Title of the Paper: SMES Device Charged
by Renewable Energy Used to Regulate Frequency of Interconnected Power System
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Authors:
Hongmei Li, Zheng Yan, Guoqin Yu, Yi Lin, Kai Niu
Abstract: Development and utilization of renewable energy source (RES) is an
important content of global energy development strategy. Being restricted by
natural conditions, the output characteristic of renewable energy generation
is stochastic. If renewable energy generator units be connected with public
grid directly, it will result in the instability of power grid. In this paper,
apply wind power as an example, using renewable energy as charge power supply
for Superconducting Magnetic Energy Storage (SMES) systems. SMES device
possesses some advantages of high efficiency, fast response and good
capability of exchange active and reactive power independently with power
system. It is a new idea for developing renewable energy. SMES can regulate
output depending on load changing on time, which can stabilize fluctuation of
frequency and reduce unnecessary power flow among tie lines. Simulation result
proved that SMES not only can improve frequency effectively, but also can
resolve the defect of inadequate spinning reserve.
Keywords: Renewable
energy, SMES, reserve capacity, primary frequency modulation. Automatic
generation control (AGC)
Title of the Paper: An Exponential
Family of Hyperbolic–Type Controllers
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Authors:
Francisco Terneus, Fernando Reyes, Eduardo Lebano
Abstract: This paper addresses the problem of position control for robot
manipulators. An Exponential family of Hyperbolic–Type controllers for robot
manipulators is presented. The proposed family consists of a large class of
control algorithms with nonlinear structure, which incorporates components of
hyperbolic type to quickly drive the position error to zero position. We
provide explicit sufficient conditions for ensuring directly global asymptotic
stability of the closed-loop system composed by the nonlinear robot dynamics
for n degrees of freedom and the proposed scheme. Besides the theoretical
results, a real-time experimental comparison is also presented to illustrate
the performance of the proposed family with other well-known control
algorithms such as PD and Hyperbolic Tangent schemes on a three degrees of
freedom direct-drive robot arm.
Keywords: Global
asymptotic stability, Lyapunov function, PD controller, robot manipulators,
position control
Title of the Paper: Design of a Cascade
Planar Transformer for Electrostatic Precipitator Use
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Authors:
Yan An Wang, Min Hu, Deng Ming Xiao, Yi Min Jiang
Abstract: The traditional high-voltage high-frequency transformer has a
drawback of low power density due to the rigorous requirements of high voltage
insulation. This paper proposes a new configuration for the magnetic core
based on planar EE cores. The parallel connection of planar cores was adopted
as a unit, and several units were cascaded to form the high-voltage
transformer. The electrical potential distribution of the proposed transformer
is more uniform than a traditional transformer, and enables a decrease in the
insulation distances. The mechanical configuration of a laboratory prototype
is discussed, as well as the electrical, parasitic, and thermal behaviors. A
prototype transformer has been designed and built with the following
characteristics: 30 kV output voltage, 30 kW output power, and 20 kHz
inverting frequency. The transformer was tested and found to have an
efficiency of better than 96%. Compared with traditional high-voltage
transformers, this transformer has good thermal behavior, good line insulation
properties and a high power density.
Keywords: High Voltage,
High Frequency, High Power Density, Planar Cores, Cascade Transformer,
Insulation
