Abstract: Green and renewable energy is getting extraordinary
consideration today, because of ecological concerns made by blazing
of fossil powers. Photovoltaic and wind power generation are the
basic decisions for delivering power in this respects. Producing
power by the sun based photovoltaic systems is known to the world,
yet control makers may get confounded to pick between on-grid and
off-grid systems. In this exploration work, an endeavor is made to
compare the off-grid (stand-alone) and on-grid (grid-connected)
frameworks. The work presents relative examination, between two
distinctive PV frameworks situated at V.V.P. Engineering College,
Rajkot. The first framework is 100 kW remain solitary and the
second is 60 kW network joined. The real-time parameters compared
are; output voltage, load current, power in-flow, power output,
performance ratio, yield factor, and capacity factor. The voltage
changes and the power variances in both frameworks are given
exceptional consideration and the examination is made between the
two frameworks to judge the focal points and confinements of both
the frameworks.
Abstract: Wavelength Division Multiplexing (WDM)
technology is the most promising technology for the proper
utilization of huge raw bandwidth provided by an optical fiber. One
of the key problems in implementing the all-optical WDM network is
the packet contention. This problem can be solved by several
different techniques. In time domain approach the packet contention
can be reduced by incorporating Fiber Delay Lines (FDLs) as optical
buffer in the switch architecture. Different types of buffering
architectures are reported in literatures. In the present paper a
comparative performance analysis of three most popular FDL
architectures are presented in order to obtain the best contention
resolution performance. The analysis is further extended to consider
the effect of different fiber non-linearities on the network
performance.
Abstract: In this paper, a prototype PEM fuel cell vehicle
integrated with a 1 kW air-blowing proton exchange membrane fuel
cell (PEMFC) stack as a main power sources has been developed for
a lightweight cruising vehicle. The test vehicle is equipped with a
PEM fuel cell system that provides electric power to a brushed DC
motor. This vehicle was designed to compete with industrial
lightweight vehicle with the target of consuming least amount of
energy and high performance. Individual variations in driving style
have a significant impact on vehicle energy efficiency and it is well
established from the literature. The primary aim of this study was to
assesses the power and fuel consumption of a hydrogen fuel cell
vehicle operating at three difference driving technique (i.e. 25 km/h
constant speed, 22-28 km/h speed range, 20-30 km/h speed range).
The goal is to develop the best driving strategy to maximize
performance and minimize fuel consumption for the vehicle system.
The relationship between power demand and hydrogen consumption
has also been discussed. All the techniques can be evaluated and
compared on broadly similar terms. Automatic intelligent controller
for driving prototype fuel cell vehicle on different obstacle while
maintaining all systems at maximum efficiency was used. The result
showed that 25 km/h constant speed was identified for optimal
driving with less fuel consumption.
Abstract: Brushless DC motors (BLDC) are widely used in
industrial areas. The BLDC motors are driven either by indirect ACAC
converters or by direct AC-AC converters. Direct AC-AC
converters i.e. matrix converters are used in this paper to drive the
three phase BLDC motor and it eliminates the bulky DC link energy
storage element. A matrix converter converts the AC power supply to
an AC voltage of variable amplitude and variable frequency. A
control technique is designed to generate the switching pulses for the
three phase matrix converter. For the control of speed of the BLDC
motor a separate PI controller and Fuzzy Logic Controller (FLC) are
designed and a hysteresis current controller is also designed for the
control of motor torque. The control schemes are designed and tested
separately. The simulation results of both the schemes are compared
and contrasted in this paper. The results show that the fuzzy logic
control scheme outperforms the PI control scheme in terms of
dynamic performance of the BLDC motor. Simulation results are
validated with the experimental results.
Abstract: The increase in electric power demand in face of
environmental issues has intensified the participation of renewable
energy sources such as photovoltaics, in the energy matrix of various
countries. Due to their operational characteristics, they can generate
time-varying harmonic and inter-harmonic distortions. For this
reason, the application of methods of measurement based on
traditional Fourier analysis, as proposed by IEC 61000-4-7, can
provide inaccurate results. Considering the aspects mentioned herein,
came the idea of the development of this work which aims to present
the results of a comparative evaluation between a methodology
arising from the combination of the Prony method with the Kalman
filter and another method based on the IEC 61000-4-30 and IEC
61000-4-7 standards. Employed in this study were synthetic signals
and data acquired through measurements in a 50kWp photovoltaic
installation.
Abstract: A broadband wire monopole antenna loaded by inhomogeneous stack of annular dielectric ring resonators (DRRs) is proposed. The proposed antenna exhibits a broad impedance bandwidth from 3 to 30 GHz. This is achieved by adding an external step matching network at the antenna feed point. The matching network is comprised of three annular DRRs possessing different permittivity values and sharing the same axial over a finite ground plane. The antenna performance is characterized using full-wave EM simulation. Compared to previous-reported wire antennas with improved bandwidth achieved by DRRs, the proposed topology provides relatively compact realization and superior broadband performance.
Abstract: This paper presents the effect of the orbit inclination
on the pointing error of the satellite antenna and consequently on its
footprint on earth for a typical Ku- band payload system. The performance assessment is examined using both analytical
simulations and practical measurements, taking into account all the
additional sources of the pointing errors, such as East-West station
keeping, orbit eccentricity, and actual attitude control performance. An implementation and computation of the sinusoidal biases in
satellite roll and pitch used to compensate the pointing error of the
satellite antenna coverage is studied and evaluated before and after
the pointing corrections performed. A method for evaluation of the performance of the implemented
biases has been introduced through measuring satellite received level
from a mono-pulse tracking 11.1m transmitting antenna before and
after the implementation of the pointing corrections.
Abstract: When evaluating the capacity of a generation park to
cover the load in transmission systems, traditional Loss of Load
Expectation (LOLE) and Expected Energy not Served (EENS)
indices can be used. If those indices allow computing the annual
duration and severity of load non covering situations, they do not take
into account the fact that the load excess is generally shifted from one
penury state (hour or quarter of an hour) to the following one. In this
paper, a sequential Monte Carlo framework is introduced in order to
compute adjusted LOLE and EENS indices. Practically, those
adapted indices permit to consider the effect of load excess transfer
on the global adequacy of a generation park, providing thus a more
accurate evaluation of this quantity.
Abstract: Hydrogen produced by means of polymer electrolyte
membrane electrolyzer (PEME) is one of the most promising
methods due to clean and renewable energy source. In the process,
some energy loss due to mass transfer through a PEM is caused by
diffusion, electro-osmotic drag, and the pressure difference between
the cathode channel and anode channel. In PEME, water molecules
and ionic particles transferred between the electrodes from anode to
cathode, Extensive mixing of the hydrogen and oxygen at anode
channel due to gases cross-over must be avoided. In recent times the
consciousness of safety issue in high pressure PEME where the
oxygen mix with hydrogen at anode channel could create, explosive
conditions have generated a lot of concern. In this paper, the steady
state and simulation analysis of gases crossover in PEME on the
temperature and pressure effect are presented. The simulations have
been analysis in MATLAB based on the well-known Fick’s Law of
molecular diffusion. The simulation results indicated that as
temperature increases, there is a significant decrease in operating
voltage.
Abstract: Microcantilevers are the basic MEMS devices, which
can be used as sensors, actuators and electronics can be easily built
into them. The detection principle of microcantilever sensors is based
on the measurement of change in cantilever deflection or change in its
resonance frequency. The objective of this work is to explore the
analogies between mechanical and electrical equivalent of
microcantilever beams. Normally scientists and engineers working in
MEMS use expensive software like CoventorWare, IntelliSuite,
ANSYS/Multiphysics etc. This paper indicates the need of developing
electrical equivalent of the MEMS structure and with that, one can
have a better insight on important parameters, and their interrelation of
the MEMS structure. In this work, considering the mechanical model
of microcantilever, equivalent electrical circuit is drawn and using
force-voltage analogy, it is analyzed with circuit simulation software.
By doing so, one can gain access to powerful set of intellectual tools
that have been developed for understanding electrical circuits Later
the analysis is performed using ANSYS/Multiphysics - software based
on finite element method (FEM). It is observed that both mechanical
and electrical domain results for a rectangular microcantlevers are in
agreement with each other.
Abstract: In this paper, approach to incoherent signal detection
in multi-element antenna array are researched and modeled. Two
types of useful signals with unknown wavefront were considered:
first one, deterministic (Barker code), and second one, random
(Gaussian distribution). The derivation of the sufficient statistics took
into account the linearity of the antenna array. The performance
characteristics and detecting curves are modeled and compared for
different useful signals parameters and for different number of
elements of the antenna array. Results of researches in case of some
additional conditions can be applied to a digital communications
systems.
Abstract: This paper introduces an effective method of
segmenting Korean text (place names in Korean) from a Korean road
sign image. A Korean advanced directional road sign is composed of
several types of visual information such as arrows, place names in
Korean and English, and route numbers. Automatic classification of
the visual information and extraction of Korean place names from the
road sign images make it possible to avoid a lot of manual inputs to a
database system for management of road signs nationwide. We
propose a series of problem-specific heuristics that correctly segments
Korean place names, which is the most crucial information, from the
other information by leaving out non-text information effectively. The
experimental results with a dataset of 368 road sign images show 96%
of the detection rate per Korean place name and 84% per road sign
image.
Abstract: This paper introduces a signal monitoring program
developed with a view to helping electrical engineering students get
familiar with sensors with digital output. Because the output of digital
sensors cannot be simply monitored by a measuring instrument such as
an oscilloscope, students tend to have a hard time dealing with digital
sensors. The monitoring program runs on a PC and communicates with
an MCU that reads the output of digital sensors via an asynchronous
communication interface. Receiving the sensor data from the MCU,
the monitoring program shows time and/or frequency domain plots of
the data in real time. In addition, the monitoring program provides a
serial terminal that enables the user to exchange text information with
the MCU while the received data is plotted. The user can easily
observe the output of digital sensors and configure the digital sensors
in real time, which helps students who do not have enough experiences
with digital sensors. Though the monitoring program was programmed
in the Matlab programming language, it runs without the Matlab since
it was compiled as a standalone executable.
Abstract: The power electronic components within Electric Vehicles (EV) need to operate in several important modes. Some modes directly influence safety, while others influence vehicle performance. Given the variety of functions and operational modes required of the power electronics, it needs to meet efficiency requirements to minimize power losses. Another challenge in the control and construction of such systems is the ability to support bidirectional power flow. This paper considers the construction, operation, and feasibility of available converters for electric vehicles with feasible configurations of electrical buses and loads. This paper describes logic and control signals for the converters for different operations conditions based on the efficiency and energy usage bases.
Abstract: In this paper, a robust fault detection and isolation
(FDI) scheme is developed to monitor a multivariable nonlinear
chemical process called the Chylla-Haase polymerization reactor,
when it is under the cascade PI control. The scheme employs a radial
basis function neural network (RBFNN) in an independent mode to
model the process dynamics, and using the weighted sum-squared
prediction error as the residual. The Recursive Orthogonal Least
Squares algorithm (ROLS) is employed to train the model to
overcome the training difficulty of the independent mode of the
network. Then, another RBFNN is used as a fault classifier to isolate
faults from different features involved in the residual vector. Several
actuator and sensor faults are simulated in a nonlinear simulation of
the reactor in Simulink. The scheme is used to detect and isolate the
faults on-line. The simulation results show the effectiveness of the
scheme even the process is subjected to disturbances and
uncertainties including significant changes in the monomer feed rate,
fouling factor, impurity factor, ambient temperature, and
measurement noise. The simulation results are presented to illustrate
the effectiveness and robustness of the proposed method.
Abstract: The photovoltaic and the semiconductor industries are
in growth and it is necessary to supply a large amount of silicon to
maintain this growth. Since silicon is still the best material for the
manufacturing of solar cells and semiconductor components so the
pure silicon like solar grade and semiconductor grade materials are
demanded. There are two main routes for silicon production:
metallurgical and chemical. In this article, we reviewed the
electrotecnological installations and systems for semiconductor
manufacturing. The main task is to design the installation which can
produce SOG Silicon from river sand by one work unit.
Abstract: This paper describes the design and implementation of
a hardware setup for online monitoring of 24 refrigerators inside
blood bank center using the microcontroller and CAN bus for
communications between each node. Due to the security of locations
in the blood bank hall and difficulty of monitoring of each
refrigerator separately, this work proposes a solution to monitor all
the blood bank refrigerators in one location. CAN-bus system is used
because it has many applications and advantages, especially for this
system due to easy in use, low cost, providing a reduction in wiring,
fast to repair and easily expanding the project without a problem.
Abstract: In the Solid-State-Drive (SSD) performance, whether
the data has been well parallelized is an important factor. SSD
parallelization is affected by allocation scheme and it is directly
connected to SSD performance. There are dynamic allocation and
static allocation in representative allocation schemes. Dynamic
allocation is more adaptive in exploiting write operation parallelism,
while static allocation is better in read operation parallelism.
Therefore, it is hard to select the appropriate allocation scheme when
the workload is mixed read and write operations. We simulated
conditions on a few mixed data patterns and analyzed the results to
help the right choice for better performance. As the results, if data
arrival interval is long enough prior operations to be finished and
continuous read intensive data environment static allocation is more
suitable. Dynamic allocation performs the best on write performance
and random data patterns.
Abstract: The application of ESS (Energy Storage Systems) in
the future grids has been the solution of the microgrid. However, high
investment costs necessitate accurate modeling and control strategy of
ESS to justify its economic viability and further underutilization.
Therefore, the reasonable control strategy for ESS which is subjected
to generator and usage helps to curtail the cost of investment and
operation costs. The rated frequency in power system is decreased
when the load is increasing unexpectedly; hence the thermal power is
operated at the capacity of only its 95% for the Governor Free (GF) to
adjust the frequency as reserve (5%) in practice. The ESS can be
utilized with governor at the same time for the frequency response due
to characteristic of its fast response speed and moreover, the cost of
ESS is declined rapidly to the reasonable price. This paper presents the
ESS control strategy to extend usage of the ESS taken account into
governor’s ramp rate and reduce the governor’s intervention as well.
All results in this paper are simulated by MATLAB.
Abstract: A theoretical study of a humidification
dehumidification solar desalination unit has been carried out to
increase understanding the effect of weather conditions on the unit
productivity. A humidification-dehumidification (HD) solar
desalination unit has been designed to provide fresh water for
population in remote arid areas. It consists of solar water collector
and air collector; to provide the hot water and air to the desalination
chamber. The desalination chamber is divided into humidification
and dehumidification towers. The circulation of air between the two
towers is maintained by the forced convection. A mathematical
model has been formulated, in which the thermodynamic relations
were used to study the flow, heat and mass transfer inside the
humidifier and dehumidifier. The present technique is performed in
order to increase the unit performance. Heat and mass balance has
been done and a set of governing equations has been solved using the
finite difference technique. The unit productivity has been calculated
along the working day during the summer and winter sessions and
has compared with the available experimental results. The average
accumulative productivity of the system in winter has been ranged
between 2.5 to 4 (kg/m2)/day, while the average summer productivity
has been found between 8 to 12 (kg/m2)/day.