Abstract: This paper demonstrates dynamic performance evaluation of load frequency control (LFC) with different intelligent techniques. All non-linearities and physical constraints have been considered in simulation studies such as governor dead band (GDB), generation rate constraint (GRC) and boiler dynamics. The conventional integral time absolute error has been considered as objective function. The design problem is formulated as an optimisation problem and particle swarm optimisation (PSO), bacterial foraging optimisation algorithm (BFOA) and differential evolution (DE) are employed to search optimal controller parameters. The superiority of the proposed approach has been shown by comparing the results with published fuzzy logic control (FLC) for the same interconnected power system. The comparison is done using various performance measures like overshoot, undershoot, settling time and standard error criteria of frequency and tie-line power deviation following a step load perturbation (SLP). It is noticed that, the dynamic performance of proposed controller is better than FLC. Further, robustness analysis is carried out by varying the time constants of speed governor, turbine, tie-line power in the range of +40% to -40% to demonstrate the robustness of the proposed DE optimized PID controller.
Abstract: This paper investigates the performance comparison of SVC (Static VAR Compensator) and DSTATCOM (Distribution Static Synchronous Compensator) to improve voltage stability in Radial Distribution System (RDS) which are efficient FACTS (Flexible AC Transmission System) devices that are capable of controlling the active and reactive power flows in a power system line by appropriately controlling parameters using ANFIS. Simulations are carried out in MATLAB/Simulink environment for the IEEE-4 bus system to test the ability of increasing load. It is found that these controllers significantly increase the margin of load in the power systems.
Abstract: In Ultra high-field MRI scanners (3T and higher),
parallel RF transmission techniques using multiple RF chains with
multiple transmit elements are a promising approach to overcome
the high-field MRI challenges in terms of inhomogeneity in the RF
magnetic field and SAR. However, mutual coupling between the
transmit array elements disturbs the desirable independent control of
the RF waveforms for each element. This contribution demonstrates
a 18 dB improvement of decoupling (isolation) performance due to
the very low output impedance of our 1 kW power amplifier.
Abstract: The out-of-band impedance environment is considered
to be of paramount importance in engineering the in-band impedance
environment. Presenting the frequency independent and constant outof-
band impedances across the wide modulation bandwidth is
extremely important for reliable device characterization for future
wireless systems. This paper presents an out-of-band impedance
optimization scheme based on simultaneous engineering of
significant baseband components IF1 (twice the modulation
frequency) and IF2 (four times the modulation frequency) and higher
baseband components such as IF3 (six times the modulation
frequency) and IF4 (eight times the modulation frequency) to
engineer the in-band impedance environment. The investigations
were carried out on a 10W GaN HEMT device driven to deliver a
peak envelope power of approximately 40.5dBm under modulated
excitation. The presentation of frequency independent baseband
impedances to all the significant baseband components whilst
maintaining the optimum termination for fundamental tones as well
as reactive termination for 2nd harmonic under class-J mode of
operation has outlined separate optimum impedances for best
intermodulation (IM) linearity.
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: Wireless Sensor Networks (WSNs), which sense
environmental data with battery-powered nodes, require multi-hop
communication. This power-demanding task adds an extra workload
that is unfairly distributed across the network. As a result, nodes run
out of battery at different times: this requires an impractical
individual node maintenance scheme. Therefore we investigate a new
Cooperative Sensing approach that extends the WSN operational life
and allows a more practical network maintenance scheme (where all
nodes deplete their batteries almost at the same time). We propose a
novel cooperative algorithm that derives a piecewise representation
of the sensed signal while controlling approximation accuracy.
Simulations show that our algorithm increases WSN operational life
and spreads communication workload evenly. Results convey a
counterintuitive conclusion: distributing workload fairly amongst
nodes may not decrease the network power consumption and yet
extend the WSN operational life. This is achieved as our cooperative
approach decreases the workload of the most burdened cluster in the
network.
Abstract: In this paper, a novel fuzzy approach is developed
while solving the Dynamic Routing and Wavelength Assignment
(DRWA) problem in optical networks with Wavelength Division
Multiplexing (WDM). In this work, the effect of nonlinear and linear
impairments such as Four Wave Mixing (FWM) and amplifier
spontaneous emission (ASE) noise are incorporated respectively. The
novel algorithm incorporates fuzzy logic controller (FLC) to reduce
the effect of FWM noise and ASE noise on a requested lightpath
referred in this work as FWM aware fuzzy dynamic routing and
wavelength assignment algorithm. The FWM crosstalk products and
the static FWM noise power per link are pre computed in order to
reduce the set up time of a requested lightpath, and stored in an
offline database. These are retrieved during the setting up of a
lightpath and evaluated online taking the dynamic parameters like
cost of the links into consideration.
Abstract: This paper integrates Octagon and Square Search
pattern (OCTSS) motion estimation algorithm into H.264/AVC
(Advanced Video Coding) video codec in Adaptive Group of Pictures
(AGOP) mode. AGOP structure is computed based on scene change
in the video sequence. Octagon and square search pattern block-based
motion estimation method is implemented in inter-prediction process
of H.264/AVC. Both these methods reduce bit rate and computational
complexity while maintaining the quality of the video sequence
respectively. Experiments are conducted for different types of video
sequence. The results substantially proved that the bit rate,
computation time and PSNR gain achieved by the proposed method
is better than the existing H.264/AVC with fixed GOP and AGOP.
With a marginal gain in quality of 0.28dB and average gain in bitrate
of 132.87kbps, the proposed method reduces the average computation
time by 27.31 minutes when compared to the existing state-of-art
H.264/AVC video codec.
Abstract: On account of the concern of the fossil fuel is
depleting and its negative effects on the environment, interest in
alternative energy sources is increasing day by day. However,
considering the importance of transportation in human life, instead of
oil and its derivatives fueled vehicles with internal combustion
engines, electric vehicles which are sensitive to the environment and
working with electrical energy has begun to develop. In this study,
simulation was carried out for providing energy management and
recovering regenerative braking in fuel cell-battery hybrid electric
vehicle. The main power supply of the vehicle is fuel cell on the other
hand not only instantaneous power is supplied by the battery but also
the energy generated due to regenerative breaking is stored in the
battery. Obtained results of the simulation is analyzed and discussed.
Abstract: In this paper, various methods of providing restricted
earth fault protection are discussed. The proper operation of high and
low impedance Restricted Earth Fault (REF) protection for various
applications has been discussed. The maloperation of a relay due to
improper placement of CTs has been identified and a simple/unique
solution has been proposed in this work with a case study. Moreover,
it is found that the proper placement of CT in high impedance method
will provide the same result with reduced CT. This methodology has
been successfully implemented in Al Takreer refinery for a 2000
KVA transformer. The outcome of the paper may be included in
IEEEC37.91 standard to give the proper guidance for protection
engineers to sort out the issues related to mal functioning of REF
relays.
Abstract: Since the last decade, there has been a rapid growth in
digital multimedia, such as high-resolution media files and threedimentional
movies. Hence, there is a need for large digital storage
such as Hard Disk Drive (HDD). As such, users expect to have a
quieter HDD in their laptop. In this paper, a jury test has been
conducted on a group of 34 people where 17 of them are students
who are the potential consumer, and the remaining are engineers who
know the HDD. A total 13 HDD sound samples have been selected
from over hundred HDD noise recordings. These samples are
selected based on an agreed subjective feeling. The samples are
played to the participants using head acoustic playback system, which
enabled them to experience as similar as possible the same
environment as have been recorded. Analysis has been conducted and
the obtained results have indicated different group has different
perception over the noises. Two neural network-based acoustic
annoyance models are established based on back propagation neural
network. Four psychoacoustic metrics, loudness, sharpness,
roughness and fluctuation strength, are used as the input of the
model, and the subjective evaluation results are taken as the output.
The developed models are reasonably accurate in simulating both
training and test samples.
Abstract: Piezoelectric actuator is treated as RC load when it is
modeled electrically. For some piezoelectric actuator applications,
arbitrary voltage is required to actuate. Especially for unidirectional
arbitrary voltage driving like as sine wave, some special inverter with
circuit that can charge and discharge the capacitive energy can be
used. In this case, the difference between power supply level and the
object voltage level for RC load is varied. Because the control gain is
constant, the controlled output is not uniform according to the voltage
difference. In this paper, for charge and discharge circuit for
unidirectional arbitrary voltage driving for piezoelectric actuator, the
controller gain is controlled according to the voltage difference. With
the proposed simple idea, the load voltage can have controlled
smoothly although the voltage difference is varied. The
appropriateness is proved from the simulation of the proposed circuit.
Abstract: Lots of motors have been being used in industry.
Therefore many researchers have studied about the failure diagnosis of
motors. In this paper, the effect of measuring environment for
diagnosis of gear fault connected to a motor shaft is studied. The fault
diagnosis is executed through the comparison of normal gear and
abnormal gear. The measured FFT data are compared with the normal
data and analyzed for q-axis current, noise and vibration. For bad and
good environment, the diagnosis results are compared. From these, it
is shown that the bad measuring environment may not be able to detect
exactly the motor gear fault. Therefore it is emphasized that the
measuring environment should be carefully prepared.
Abstract: This paper proposes a novel heuristic algorithm that aims to determine the best size and location of distributed generators in unbalanced distribution networks. The proposed heuristic algorithm can deal with the planning cases where power loss is to be optimized without violating the system practical constraints. The distributed generation units in the proposed algorithm is modeled as voltage controlled node with the flexibility to be converted to constant power factor node in case of reactive power limit violation. The proposed algorithm is implemented in MATLAB and tested on the IEEE 37 -node feeder. The results obtained show the effectiveness of the proposed algorithm.
Abstract: In this paper we present the design of an optical
device based on a Herriott multi-pass cell fabricated on a small sized
acrylic slab for heat flux measurements using the deflection of a laser
beam propagating inside the cell. The beam deflection is produced by
the heat flux conducted to the acrylic slab due to a gradient in the
refractive index. The use of a long path cell as the sensitive element
in this measurement device, gives the possibility of high sensitivity
within a small size device. We present the optical design as well as
some experimental results in order to validate the device’s operation
principle.
Abstract: In internet of things (IoT) system, the communication
scheme with reliability and low power is required to connect a
terminal. Cooperative communication can achieve reliability and
lower power than multiple-input multiple-output (MIMO) system.
Cooperative communication increases the reliability with low
power, but decreases a throughput. It has a weak point that the
communication throughput is decreased. In this paper, a novel scheme
is proposed to increase the communication throughput. The novel
scheme is a transmission structure that increases transmission rate.
A decoding scheme according to the novel transmission structure is
proposed. Simulation results show that the proposed scheme increases
the throughput without bit error rate (BER) performance degradation.
Abstract: In this paper, synchronization of multiple chaotic
semiconductor lasers is achieved by appealing to complex system
theory. In particular, we consider dynamical networks composed by
semiconductor laser, as interconnected nodes, where the interaction
in the networks are defined by coupling the first state of each node.
An interest case is synchronized with master-slave configuration in
star topology. Nodes of these networks are modeled for the laser and
simulate by Matlab. These results are applicable to private
communication.
Abstract: This paper considers the design of Dual Proportional-
Integral (DPI) Load Frequency Control (LFC), using gravitational
search algorithm (GSA). The design is carried out for nonlinear
hydrothermal power system where generation rate constraint (GRC)
and governor dead band are considered. Furthermore, time delays
imposed by governor-turbine, thermodynamic process, and
communication channels are investigated. GSA is utilized to search
for optimal controller parameters by minimizing a time-domain based
objective function. GSA-based DPI has been compared to Ziegler-
Nichols based PI, and Genetic Algorithm (GA) based PI controllers
in order to demonstrate the superior efficiency of the proposed
design. Simulation results are carried for a wide range of operating
conditions and system parameters variations.
Abstract: There are a number of Distributed Generations (DGs)
installed in microgrid, which may have diverse path and direction of
power flow or fault current. The overcurrent protection scheme for the
traditional radial type distribution system will no longer meet the
needs of microgrid protection. Integrating the Intelligent Electronic
Device (IED) and a Supervisory Control and Data Acquisition
(SCADA) with IEC 61850 communication protocol, the paper
proposes a Microgrid Protection Management System (MPMS) to
protect power system from the fault. In the proposed method, the
MPMS performs logic programming of each IED to coordinate their
tripping sequence. The GOOSE message defined in IEC 61850 is used
as the transmission information medium among IEDs. Moreover, to
cope with the difference in fault current of microgrid between
grid-connected mode and islanded mode, the proposed MPMS applies
the group setting feature of IED to protect system and robust
adaptability. Once the microgrid topology varies, the MPMS will
recalculate the fault current and update the group setting of IED.
Provided there is a fault, IEDs will isolate the fault at once. Finally, the
Matlab/Simulink and Elipse Power Studio software are used to
simulate and demonstrate the feasibility of the proposed method.
Abstract: Space Vector Pulse Width Modulation is popular for
variable frequency drives. The method has several advantages over
carried based PWM and is computation intensive. The
implementation of SVPWM for multilevel inverter requires special
attention and at the same time consumes considerable resources. Due
to faster processing power and reduced over all computational
burden, FPGAs are being investigated as an alternative for other
controllers. In this paper, a space vector PWM algorithm is
implemented using FPGA which requires less computational area and
is modular in structure. The algorithm is verified experimentally for
Neutral Point Clamped inverter using FPGA development board
xc3s5000-4fg900.